Chapter 16 objectives: cardiovascular emergencies

pathophysiology of the cardiovascular system: acute coronary syndrome

-ACS -term used to describe a group of symptoms caused by myocardial ischemia (decrease in blood flow to the heart, which leads to chest pain through reduction of O2 and nutrients to the tissues of the heart). -can be a temporary situation known as AGINA PECTORIS or a more serious condition, an AMI

AEDs

-AEDs deliver electrical energy from one pad to the other to electrically stun the heart and allow it to resume normal function. -factors involved in the defibrillation include voltage, current, and impedance. most AEDs are set up to adjust the voltage based on impedance (or resistance of the body to the flow of electricity) to deliver the proper amount of current, which is what actually causes the cells to defibrillate. -computer inside the AED is specially programmed to recognize rhythms that require defibrillation to correct, most commonly ventricular fibrillation. -the machine is fast, and it delivers the most important treatment for a patient in ventricular fibrillation: an electrical shock. it can be delivered within 1 minute of your arrival at the patient's side. -they are easy to operate. the shock can be given through remote, adhesive defibrillator pads. make sure the pad is not lying on wet ground or touching metal objects when the patient is being shocked. -all patients in cardiac arrest should be analyzed with an AED but may not require shock. asystole (flatline) indicates that no electrical activity remains. pulseless electrical activity refers to a state of cardiac arrest that exists despite an organized electrical complex. in both cases, CPR should be initiated ASAP beginning with chest compressions.

discuss the reasons for early defibrillation

-CPR helps patients in cardiac arrest b/c it prolongs the period during which defibrillation can be effective. rapid defibrillation has successfully resuscitated many patients with cardiac arrest due to ventricular fibrillation. -defibrillation works best if it takes place within 2 minutes of the onset of the cardiac arrest. seconds matter when a patient is in cardiac arrest.

left ventricular assist devices

-LVADs are used to enhance the pumping of the LV in patients with severe heart failure or in patients who need a temporary boost due to an MI. -most common ones have an internal pump unit and an external battery pack. these pumps may pump the blood in pulsations just like the natural heart, or they may be continuous, in which the patient will not have any palpable pulses. -unless it malfunctions you should not need to deal with it. -contact medical control for assistance if you are unsure on what to do. -LVADs provide a number to call for assistance. transport all LVAD supplies and batter packs to the hospital with the patient.

anatomy, physiology, pathophysiology, assessment, and management of thromboembolism

-a blood clot that is floating through blood vessels until it reaches an area too narrow for it to pass, causing it to stop and block the blood flow at that point. -tissues downstream from the blood clot will have a lack of O2 (hypoxia). the hypoxic tissues will die eventually. -if a blockage occurs in a coronary artery this is known as: ACUTE MYOCARDIAL INFARCTION (AMI), classic heart attack. occurs when a blood clot prevents blood flow to an area of the heart muscle.

define cardiac arrest

-a complete cessation of cardiac activity: electrical, mechanical or both. it is indicated in the field by the absence of a carotid pulse. -when you arrive to find a patient who appears to be in cardiac arrest, you should automatically follow your CPR training.

AMI without the classic chest pain is referred to as

-a silent MI -heart disease is the number 1 killer of women in the US -EMTs should consider AMI even when the classic symptom of chest pain is not present.

sudden death: AMI

-about 40% of all patients with an AMI do not reach the hospital alive. sudden death is usually the result of cardiac arrest, in which the heart fails to generate effective blood flow. -cannot feel a pulse in someone experiencing cardiac arrest but the heart may still be twitching. the heart is using up energy without pumping any blood. such an abnormality of heart rhythm is a VENTRICAL DYSRHYTHMIA, known as ventricular fibrillation. -other dysrhythmias may follow an AMI, usually within the first hour. usually premature ventricular contractions or extra betas in the damaged ventricle occur. -premature ventricular contractions by themselves may be harmless and are common among healthy people and sick people

after AED shocks

-after care depends on location and EMS system SO follow local protocols. -after the AED protocol is completed, one of the following is likely: pulse is regained, no pulse and the AED indicates shock, or no pulse and the AED indicated no shock. -patients who do not regain a pulse on the scene of the cardiac arrest usually do not survive. what you do with these patients depends on your EMS system. whether you transport them or wait for ALS to arrive should be in the local protocols established by medical control. -if paramedics or another ALS service is responding to the scene, the best option usually is to stay where you are and continue the sequence of shocks and CPR -administering CPR while patients are being moved or transported is usually not effective. the best chance of survival is when the patient is resuscitated where found, unless the location is unsafe.

fully automated defibrillator vs. semiautomated

-all AEDs require a certain degree of operator interaction, beginning with turning on the machine and applying the pads. operator has to push a button to deliver an electrical shock regardless of the model. -there are few fully automatic AEDs: which would deliver a shock without the operator pressing the button. -all manufactures are now producing only semiautomated external defibrillators

recognize that not all patients in cardiac arrest require an electric shock

-all patients in cardiac arrest should be analyzed with an AED but may not require shock. asystole (flatline) indicates that no electrical activity remains. pulseless electrical activity refers to a state of cardiac arrest that exists despite an organized electrical complex. in both cases, CPR should be initiated ASAP beginning with chest compressions.

indications and contraindications for use of an AED

-all patients in cardiac arrest should be analyzed with an AED. -only apply the AED to a pulseless, unresponsive patient and stay clear of the patient while the AED is analyzing the heart rhythm and delivering shocks.

anatomy, physiology, pathophysiology, assessment, and management of aortic aneurysm/ dissection.

-an aortic aneurysm is a weakness in the wall of the aorta. the aorta dilates at the weakened area, which makes it susceptible to rupture. -a dissecting aneurysm occurs when the inner layers of the aorta become separated, allowing blood to flow b/w the layers at high pressure. -uncontrolled hypertension is the primary cause of dissecting aortic aneurysms. this separation of layers weakens the wall of the aorta, making it more likely to be ruptured under conditions of high blood pressure. -if the aorta ruptures, the amount of internal blood loss will be so large that the patient will die almost immediately. -signs and symptoms if dissecting aortic aneurysm: very sudden chest pain located in the anterior part of the chest or in the back b/w the shoulder blades. may be difficult to differentiate the chest pain of a dissecting aortic aneurysm from that of an AMI. -pain for an AMI is often preceded by other symptoms: nausea, indigestion, weakness, and sweating; and tends to come on gradually, getting more severe with time and often described as pressure rather than stabbing. -pain from a dissecting aortic aneurysm usually comes on full force from one minute to the next. patient may exhibit a difference in BP b/w arms or diminished pulses in the lower extremities. -aortic aneurysms are almost impossible to diagnose in the prehospital setting, but consider them a possibility in any patient with significant hypertension. transport the patient without delay.

recognize that many patients will have had cardiac surgery and may have defibrillators (implantable and vest)

-an automatic implantable cardiac defibrillator is attached directly to the heart and continuously monitors heart rhythm, delivering shocks as needed. the electricity from it is so low that it has no effects on rescuers. -treatment should include performing CPR and using an AED if the patient goes into cardiac arrest. -an alternate to the implantable cardiac defibrillator is the external defibrillator vest. this is vest with built in monitoring electrodes and defibrillation pads, which is worn by the patient under their clothing. the vest is attached to a monitor worn on a belt or hung from a shoulder strap. monitor provides alerts and voice prompts when it recognizes a dangerous rhythm and before a shock is delivered. this device uses high energy shocks similar to an AED, SO you should avoid contact with the patient if the device warns you that it is about to deliver a shock. blue gel under the large defibrillation pads indicates that the device has already delivered at least one shock. -if a patient is in cardiac arrest, the vest should remain in place while CPR is being performed unless it interferes with compressions. if it is necessary to remove the vest, remove the battery from the monitor and then remove the vest. you can use your own AED on the patient. any patient who is wearing the device that has already delivered a shock should be transported to the hospital for further evaluation.

pulse

-as the LV contracts, it ejects a forceful wave of blood through the arteries. as the blood passes through an artery during systole, a pulse is generated. this pulse can be felt by placing a finger on the skin over the artery at a point where the artery lies near the skin surface and gently compressing. -pulses felt in the extremities, such as the radial and the posterior tibial, are peripheral pulses. pulses near the trunk of the body, such as the femoral and carotid pulses, are known as central pulses. -EMTs should compare proximal and distal pulses bilaterally, when applicable, to determine any differences in quality or strength that could indicate the patient's condition is progressing to decompensated shock.

discuss the procedures to follow for standard operation of the various types of AEDs

-as the operator of the AED, you are responsible for making sure the electricity does not injure anyone, including yourself. remote defibrillation using pads allows you to distance yourself safely from the patient. as long as you place the pads in the correct position and make sure no one is touching the patient, you should be safe.

words of wisdom: heart rate

-athletes may have a slower heart rate as a result of normal physiologic changes related to physical conditioning -tachycardia is a normal physiologic response to exercise to ensure adequate tissue perfusion. -pain, fear, and excitement may also cause a person to be tachycardic.

aging with the cardiovascular system

-cardiovascular system undergoes changes as people get older. the heart will show the effects of aging. as the heart's muscle mass and tone decrease, the amount of blood pumped out of the heart per beat decreases. the residual (reserve) capacity of the heart is also reduced SO when the vital organs of the body need additional blood flow, the heart cannot meet the need. when the blood flow to the tissues is decreased, the organs suffer. -heart muscle is stimulated by electricity and has its own electrical system. under normal conditions, electrical impulses travel throughout the heart, resulting in the contraction of the heart muscle and the pumping of blood from the heart's chambers. with aging, the electrical system can deteriorate, causing the heart's contraction to weaken or, if blood flow to the heart muscle is affected, extra beats to form. with decreased strength of contraction, the heartbeat is weaker and blood flow to the tissues is reduced. if extra beats are produced, the patient's heart rhythm will be irregular. -arteries are also affected. arteriosclerosis (hardening of arteries) can develop, affecting perfusion of the tissues. increased chance of heart attack or stroke due to decreased blood flow or plaque formations in the narrowed arteries. -patients with diabetes can experience reduced circulation to the hands and feet, which makes peripheral pulses harder to detect. it also puts the hands and feet as risk for infection and ulceration. -in some older patients with angina and AMI, chest pain is absent, and the clinical picture can be confused with other, noncardiac conditions. patients may have a chief complaint of syncope (fainting), fatigue, or shortness of breath.

administrating nitroglycerin

-check the condition of the medication and its expiration date, and do not administer contaminated or expired meds. make sure the medication is prescribed to the patient. -be sure to where gloves when handling nitroglycerin tablets or spray b/c it is easily absorbed through the skin. if you handle it with your bare hands it may be absorbed into your body, causing you to experience a very painful headache. -if the patient has on a nitroglycerin patch when you arrive, be sure to carefully remove it if the patient is hypotensive or in cardiac arrest (before use of AED). -after you obtain permission from medical control help the patient administer prescribed nitroglycerin. it works in most patients within 5 mins. Nitrostat is one trade name for it. -patients take one dose of nitroglycerin under the tongue whenever they have an episode of angina that does not immediately go away with rest. if the pain is still present after 5 mins, patients are typically instructed by their physicians to take a second dose. if a second dose does not work, most patients are told to take a third and then call for EMS. if the patient has not taken all three doses, you can help to administer the medication, if you are allowed to by local protocol. -nitroglycerin will lose it potency over time, especially if exposed to light. when it loses its potency, patients may not feel the fizzing sensation when the tablet is placed under their tongue, and they may not experience normal burning sensation and headache that often accompany nitroglycerin administration. -fizzing only occurs with potent tablet, not with spray.

if the AED advises no shock and the patient has a pulse...

-check the patient's breathing. if the patient is breathing adequately, give O2 via nonrebreathing mask, adjusting the flow as soon as pulse oximetry gives a reading, and transport. -if the patient is not breathing adequately, provide artificial ventilations with a BVM or pocket mask device attached to 100 percent O2 and transport. -ensure that proper airway techniques are used at all times -if the patient has no pulse, perform 5 cycles of CPR beginning with chest compressions. after 2 mins of CPR, reanalyze the patients cardiac rhythm. if the AED advises shock, deliver it and do CPR. repeat steps if needed. -if the patient has no pulse and the AED advises no shock, perform 5 cycles of CPR. after 5 cycles, reanalyze the patients cardiac rhythm. if no shock is advised continue CPR. transport the patient and contact medical control as needed.

pathophysiology of the cardiovascular system

-chest pain or discomfort that is related to the heart usually stems from a condition called ischemia (decreased blood flow to the heart). -b/c of partial or complete blockage of blood flow through the coronary arteries, heart tissue fails to get enough O2 and nutrients. tissue begins to starve, and if blood flow is not restored, it dies. -ischemia heart disease involves a decrease in blood flow to one or more portions of the heart muscle. -coronary artery disease is the number one cause of death for men and women. peak incidence of heart disease occurs b/w 45-64. can also strike teens and people in their 90s.

major controllable risk factors for an AMI

-cigarette smoking -high BP -elevated cholesterol levels -elevated blood glucose level (diabetes) -lack of exercise -obesity

blood

-consists of fluid and several types of cells. red blood cells are the most numerous and give the blood its color. they carry O2 to the body's tissues and remove Co2. -larger white blood cells help to fight infection -platelets, which help the blood to clot, are much smaller than red and white blood cells. -plasma is the fluid that the cells float in. it is a mixture of water, salts, nutrients, and proteins

perfusion

-constant flow of oxygenated blood to the tissues. -good perfusion requires: a well-functioning heart/pump, an adequate volume of "fluid" or blood, and the blood must be carried in a properly sized "container" so the BV must be appropriately constricted to math the volume of blood available. -heart must operate at an appropriate rate b/c a rate that is too slow or fast will reduce the volume of blood circulated and reduce the cardiac output. when the heart beats too fast, there is not enough time b/w contractions for the heart to refill completely, and when the heart beats too slowly, the volume of blood circulated per minute decreases due to the slow pulse rate. -if there is blood loss through hemorrhage, the reduced volume will limit the amount of tissue that can be perfused. -if the BV dilate and the volume of fluid remains the same, there will not be enough blood to fill the BV and perfusion will be reduced.

post-arrest care

-continuing ventilation at less than 12 beats/min to achieve an ETCo2 of 35-40 mm Hg. -maintain oxygen saturation b/w 94-99 percent. -assure BP is above 90 mm Hg -maintain blood glucose levels in the patient who is hypoglycemic. -cardiopulmonary and neurologic support at the hospital

explain the role played by medical direction in the use of AEDs

-defibrillation of the heart is a medical procedure. -medical director of your service should approve the written protocol that you will follow in caring for patients in cardiac arrest -there should be a review of each incident in which the AED is used. after returning from the hospital or the scene, discuss with the rest of the team what happened. this will help all members of the team learn from the incident. review such events by using the written report and the devices recordings. -there should also be a review of the incident by your service's medical director or quality improvement officer. quality improvement involves people using AEDs and the responsible EMS system management. this review should focus on speed of defibrillation, the time from the call to the shock. the ultimate goal is shock 100% of patients within 1 minute of the call. all systems continuously work on improving patient care.

patient assessment procedures for cardiovascular problems: patient assessment procedures for cardiovascular problems: history taking

-determine and investigate the chief complaint and know more about the history of the present illness. -for a conscious medical patient, begin with taking a brief past history, identifying associated signs and symptoms, and identifying pertinent negatives. -a chief complaint of chest pain or discomfort, shortness of breath, or dizziness should be taken seriously. act professionally and be calm. speak to the patient in a normal voice. let them know that trained responders are present to provide care and that they will soon be taken to the hospital. most patients will be scared/ frightened. your professional attitude is important and do not lie and offer false reassurance. -begin by asking questions about the current situation. determine whether the patient is experiencing chest pain or discomfort and whether there are any other signs and symptoms. determine whether the patient is having respiratory difficulty b/c this is common with chest pain. -if the patient is experiencing dyspnea, find out whether it is related to exertion and whether it is related to the patient's position. often patients with chest pain experience worse difficulty breathing when they are lying down. determine whether the dyspnea is continuous or if it changes, especially with deep breathing. -note whether the patient has a cough or whether the cough produces sputum. ask about other signs and symptoms that are commonly found such as nausea and vomiting, fatigue, headache, and palpitations (a feeling of the heart skipping a beat or racing). -make sure to ask about any trauma the patient might have experienced during the last few days. be sure to record your findings, include those that are negative. -when you ask about medical conditions, be sure to ask whether the patient takes medications for those. if the patient tells you they take prescription meds, ask what condition they are for. -ask about the last oral intake. and ask about home remedies the patient might have used -be sure to include OPQRST questions when you are obtaining the symptoms as part of the SAMPLE history. using OPQRST helps you understand the details of specific complaints.

pathophysiology of the cardiovascular system: congestive heart failure (left and right side heart failure)

-failure of the heart occurs when the ventricular heart muscle is so permanently damaged that is can no longer keep up with the return flow of blood from the atria. -CHF can occur any time after a AMI, in the setting of heart valve damage, or as a consequence of long standing high blood pressure. any condition that weakens the pumping strength of the heart may cause CHF and this often happens b/w the first few hours and the first few days after a heart attack. -pumping function of the LV can be damaged by coronary artery disease and also by diseased heart valves or chronic hypertension. when the muscle can no longer contract effectively, the heart tries other ways to maintain an adequate cardiac output. the heart rate increases and the LV enlarges in an effort to increase the amount of blood pumped each minute. -when these adaptations can no longer make up for the decreased heart function, CHF develops. lungs become congested with fluid once the left side of the heart fails to pump the blood effectively. blood tends to back up in the pulmonary veins, increasing the pressure in the capillaries of the lungs. when the pressure in the capillaries exceeds a certain level, fluid passes through the walls of the capillary vessels and into the alveoli. this is PULMONARY EDEMA. may occur suddenly, as in an AMI, or slowly over months, as in chronic CHF. -sometimes in patients with an onset of acute CHF, severe pulmonary edema occurs and the patient has pink, frothy sputum and severe dyspnea. -if the right side of the heart is damaged, fluid collects in the body, often showing up as swelling in the feet and legs. this collection of fluid in the part of the body that is closest to the ground is DEPENDENT EDEMA. -chronic dependent edema may indicated underlying heart disease. since the right side of the heart supplies the preload for the left side, right heart failure can result in inadequate supply of blood to the LV resulting in a drop in the systemic BP. -left sided failure often leads to right sided failure.

anatomy, physiology, pathophysiology, assessment, and management of angina pectoris

-for a brief time, heart tissues are not getting enough O2, pain is called angina pectoris -temporary -can result for a spasm of an artery, but most often a symptom of atherosclerotic coronary artery disease. -occurs when the heart's need for O2 exceeds its supply, usually during periods of physical or emotional stress when the heart is working hard. large meal or sudden fear may trigger an attack too. -when the increased O2 demand goes away, the pain typically does too. -anginal pain is describes as crushing, squeezing, or like someone is standing on your chest. usually felt in the mid portion of the chest, under the sternum. pain can radiate to the jaw, arms (frequently left), and the midportion of the back or epigastrium (upper middle region of the abdomen). -pain usually lasts for 3-8 mins, rarely longer than 15. -may be associated with shortness of breath, nausea, or sweating. -usually disappears promptly with rest, supplemental O2, or nitroglycerin, all of which decrease the need or increase the supply of oxygen to the heart. -does not mean that the heart cells are dying. it is a warning that you and the patient should take seriously. b/c the O2 supply is diminished, the electrical system can be compromised, and the person is at risk for significant cardiac rhythm problems. -can be separated into stable and unstable. -unstable= characterized by pain or discomfort in the chest of coronary origin that occurs in response to progressively less exercise or fewer stimuli than ordinarily required to produce angina. can lead to AMI if untreated. -stable= characterized by pain in the chest of the coronary origin that is relived by the things that normally relive it in a given patient (rest, or taking nitroglycerin). -EMS is usually involved when stable angina becomes unstable. a patient whose pain is normally relieved by something isn't working. -patients experiencing chest pain or discomfort, should always be treated as if they are having an AMI.

blood pressure

-force of circulating blood against the walls of the arteries -systolic BP is the maximum pressure generated in the arms and legs during the contraction of the LV, during the time period known as systole. -as the LV relaxes in the stage known as diastole, the arterial pressure falls. when the LV relaxes, the aortic valve closes and blood flow b/w the LV and the aorta stops. diastolic BP is the pressure exerted against the walls of the arteries while the LV is at rest. -cardiac cycle consists of one systolic and one diastolic time period

patient assessment procedures for cardiovascular problems: primary assessment

-form a general impression of their condition to recognize and address life threats. -perform a primary assessment of the patient. if the patient is unresponsive and is not breathing, begin CPR, starting with chest compressions, and call for an AED. -AED should be applied if the patient is pulses, not breathing (apneic), and unresponsive. consider calling for ALS backup -next assess airway and breathing. -unless the patient is unresponsive, the airway will most likely be patent. responsive patients should be able to maintain their own airway. some episodes of cardiac compromise may produce dizziness or even fainting spells (syncope). if dizziness or fainting has occurred, consider the possibility of a spinal injury from a fall. assess and treat the patient as appropriate. -assess the patient's breathing to determine if is adequate to provide enough O2 to an ailing heart. if the rate is too fast or slow, the depth of respiration seems to be too shallow, or the patient is struggling to breathe, respirations are inadequate. -listen for abnormal breath sounds at this time b/c these can be important indicators of respiratory distress. some patients feel shortness of breath even though there are no obvious signs of respiratory distress. pulse oximetry is a good tool in treatment of respiratory distress and should be applied at this time. -if the patient is having chest pain and their O2 saturation is less than 94%, administer O2 at 4 L/min via a nasal cannula. if they do not improve quickly, increase the O2 concentration. apply a nonrebreathing mask at 15 L/min. the goal is to maintain the O2 saturation level b/w 95% and 99%. -if the patient is not breathing or has inadequate breathing, ensure adequate ventilations with A BVM and 100% oxygen. -patients experiencing pulmonary edema may require positive pressure ventilation with a BVM or CPAP. -CPAP is the most effective way to assist a person with CHF to breathe effectively and prevent an invasive airway managing technique. -now assess circulation. determine the rate and quality of the patient's pulse. is the pulse rhythm regular or irregular? is the pulse too fast or slow? if you find abnormalities in the pulse you should be more suspicious. -assess the patient's skin color, condition, moisture, and temp as well as the capillary refill time. -consider treatment for cardiogenic shock early to reduce the workload of the heart. place the patient in a comfortable position, usually sitting up and well supported. provide reassurance that appropriate treatment is begin given for the condition to reduce the patient's anxiety. -make a transport decision based on whether you were able to stabilize life threats during the primary assessment. remainder of assessment can be performed en route if time allows. -most patients with chest pain should be transported immediately. patients with cardiac problems should be transported in the most gentle, stress relieving manner possible. you can do a lot to calm your patient and reduce the release of heart damaging adrenaline through your reassurance and by creating a ride to the hospital that is pleasant. try not to allow the patient to exert themselves, strain, or walk. lift the patient if needed. -some medical directors have written protocols requiring patients with suspected cardiac emergencies to be transported to cardiac specialty centers with certain capabilities. be sure to know your local protocol

furosemide (lasix), digoxin, and metoprolol (toprol)

-furosemide is a diuretic, digoxin increases the strength of heart contractions, and metoprolol lowers BP -these meds are often prescribed together for patients with chronic heart failure and may alert you to carefully evaluate the lungs for presence of crackles, which indicate fluid in the lungs, and need to increase the amount of O2 being delivered.

if the patient is responsive, obtain the SAMPLE history and ask the following questions specific to a cardiovascular emergency: history taking

-have you had a heart attack? -have you been told that you have heart problems? -have you ever been diagnosed with angina, heart failure, or heart valve disease? -have you ever had high BP? -have you ever been diagnosed with an aneurysm? -do you have any respiratory diseases such as emphysema or chronic bronchitis? -do you have diabetes or have you ever had any problems with your blood sugar? -have you ever had kidney disease? -do you have any risk factors for coronary artery disease: smoking, high BP, or high stress lifestyle? -is there a family history of heart disease? -do you currently take any medications?

The basic anatomy of the cardiovascular system:

-heart is a simple organ. divided down the middle into two sides (left and right) by a wall called the septum. each side of the heart has an atrium/ upper chamber, to receive incoming blood, and a ventricle/lower chamber to pump outgoing blood. -blood leaves each of the 4 chambers of the heart through a one-way valve. these valves keep the blood from moving through the circulatory system in the proper direction. -aorta: the body's main artery, receives the blood ejected from the LV and delivers it to ALL the other arteries so they can carry blood to the tissues of the body. -the right side of the heart receives oxygen-poor blood from the veins of the body. blood from the vena cava enters the RA, which then fills the RV, blood flows into the pulmonary circulation in the lungs, where the blood is oxygenated. as the blood reaches the lungs, it receives fresh oxygen from the alveoli and carbon dioxide waste is removed from the blood and moved into the alveoli. the blood then returns to the heart through the pulmonary veins. -left side of the heart receives oxygen-rich blood from the lungs through the pulmonary veins. blood enters the LA and then passes into the LV. the LV is more muscular than the RV because it must pump blood into the aorta to supply all the other arteries of the body. -ANS has two parts: sympathetic nervous system and the parasympathetic nervous system.

the basic physiology of the cardiovascular system

-hearts job is to pump blood to supply oxygen-enriched red blood cells to the tissues of the body -heart contains more than muscle tissue. heart's electrical system controls heart rate and enables the atria and ventricles to work together. normal electrical impulses begin in the sinus node, which is in the upper part of the RA and is also know as the sinoatrial (SA) node. impulses travel across both atria, stimulating them to contract. b/w the atria and ventricles, the impulses cross a bridge of special electrical tissue called the atrioventricular (AV) Node. the signal is slowed for about 1-2 tenths of a second to allow blood time to pass from the atria to the ventricles. the impulses then exit the atrioventricular node and spread throughout both ventricles via the bundle of His, the right and left bundle branches, and the Purkinjie fibers, causing the ventricular muscle cells to contract. -cardiac muscle cells have a special characteristic called automaticity that is not found in any other type of muscle cells. automaticity allows a cardiac cells to contract spontaneously without a stimulus from a nerve source. -normal impulses in the heart start at the sinoatrial node. as long as impulses come from this node, the other myocardial cells will contract when the impulse reaches them. if no impulse arrives, the other myocardial cells are capable of creating their own impulses and stimulating a contraction of the heart, although at a generally slower rate. -the stimulus that originates in the sinoatrial node is controlled by impulses from the brain, which arrive by way of the autonomic nervous system. the ANS is the part of the brain that controls that functions of the body that do not require conscious thought (heartbeat, respirations, dilation and constriction of BV, and digestion of food). -sympathetic nervous system is also known as the fight or flight system and makes adjustments to the body to compensate for increased physical activity. speeds up HR, increases RR and depth, dilates BV in the muscles, and constricts BV in the digestive system. -parasympathetic nervous system directly opposes the sympathetic nervous system. it slows the heart and respiratory rates, constricts BV in the muscles, and dilates BV in the digestive system. -these two systems balance each other out but in stressful situations the sympathetic nervous system gains primary control, whereas in times of relaxation, the parasympathetic system takes control.

anatomy, signs and symptoms, and management of hypertensive emergencies

-hypertension is any systolic blood pressure greater than 140 mm Hg or a diastolic pressure greater than 90 mm Hg. -hypertensive emergency: occurs only with a systolic pressure greater than 180 mm Hg or a rapid rise in the systolic pressure. -signs and symptoms are related to the effects of hypertension. some patients with chronic hypertension may not experience signs or symptoms until their systolic pressure is significantly higher than this value. -one of the most common signs is a sudden severe headache. others include: strong bounding pulse, ringing in the ears, nausea and vomiting, dizziness, warm skin (dry or moist), nosebleed, altered mental status, and even sudden development of pulmonary edema. -untreated situations can lead to a stroke or a dissecting aortic aneurysm. -if you suspect your patient is experiencing a hypertensive emergency: attempt to make them feel comfortable and monitor the blood pressure regularly. position the patient with the head elevated and transport rapidly to the ED. consider ALS assistance for the patient. paramedics may be able to administer meds to lower the BP to a safer level. if ALS can be on the scene quickly, contact them early and allow them to transport the patient from the scene. if the transport distance is long, consider asking ALS unit to meet you along the way and take over patient care and transportation. -best prehospital care is getting the patient to the hospital as quickly and safely as possible.

if you transport a patient while performing CPR, you need a plan for managing the patient in the ambulance...

-ideally you will have two EMTs in the patient compartment while a third drives. you may deliver additional shocks at the scene or en route with the approval of medical control. -AEDs cannot analyze the rhythm while the vehicle is in motion, nor is it safe to defibrillate in a moving ambulance. you should come to a complete stop if more shocks are needed.

steps to take in the assessment of a patient with chest pain or discomfort

-if the patient is having chest pain and their O2 saturation is less than 94%, administer O2 at 4 L/min via a nasal cannula. if they do not improve quickly, increase the O2 concentration. apply a nonrebreathing mask at 15 L/min. the goal is to maintain the O2 saturation level b/w 95% and 99%. -most patients with chest pain should be transported immediately. patients with cardiac problems should be transported in the most gentle, stress relieving manner possible. you can do a lot to calm your patient and reduce the release of heart damaging adrenaline through your reassurance and by creating a ride to the hospital that is pleasant. try not to allow the patient to exert themselves, strain, or walk. lift the patient if needed.

asystole

-if uncorrected, unstable ventricular tachycardia or ventricular fibrillation will eventually lead to asystole. -absence of all heart electrical activity. -without CPR it may occur within minutes. it usually reflects a long period of ischemia, and nearly all patients you find in asystole will die.

Management of return of spontaneous circulation

-if you are able to restore a heartbeat through the use of an AED, monitor for spontaneous respirations, provide O2 via a BVM at 10-12 breaths/min and maintain an oxygen saturation b/w 94-99 percent. -assess the patient's BP and see if they can follow simple commands -if ALS is not on scene or en route, begin transport to the closest hospital depending on local protocol

cardiac arrest during transport

-if you are traveling to the hospital with an unconscious patient, check the pulse at least every 30 seconds. if a pulse is not present... 1. stop the vehicle 2. if the AED is not ready, perform CPR until it is available 3. call for help in the form of ALS support or any other available resource as appropriate based on circumstances and local protocol. 4. analyze the rhythm. 5. deliver one shock, if indicated, and resume CPR 6. continue resuscitation according to local protocol.

discuss the emergency medical care for the patient with cardiac arrest: performing defibrillation

-if you witness a patient in cardiac arrest, begin CPR starting with chest compressions and attach the AED ASAP. -as soon as the AED is turned on and attached, follow the instructions to analyze and deliver shocks to the patient. make sure to minimize the time when you are not performing chest compressions. -at each defibrillation the person performing compressions should switch places with the person providing ventilations so that neither get overtired. -after each defibrillation, resume CPR with compressions first.

recognize that many patients will have had cardiac surgery and may have implanted pacemakers or defibrillators

-in a coronary artery bypass graft, a blood vessel from the chest or leg is sewn directly from the aorta to a coronary artery beyond the point of the obstruction. -percutaneous transluminal coronary angioplasty: aims to dilate, rather than bypass, the coronary artery. a tiny balloon is attached to the end of a long, thin tube. tube is introduced through the skin into a large artery, usually in the groin, and then threaded into the narrowed coronary artery, with radiographs serving as a guide. once the balloon is in position inside the coronary artery, it is inflated. the balloon is then deflated, and the tube is removed from the body. -sometimes a metal mesh cylinder called a stent is placed inside the artery instead of or after the balloon. it is left in place permanently to help keep the artery from narrowing again. -a patient who has had an AMI or angina in the past will maybe have one of these procedures. patients who have had a bypass graft will have a long surgical scar on the chest. patients who have had an angioplasty or a coronary artery stent will usually not. -pacemakers are inserted when the electrical control system of the heart is so damaged that it cannot function properly. they deliver an electrical impulse through wires that are in direct contact with the myocardium. it is generally placed under a heavy muscle or a fold of skin. typically resembles a small silver dollar under the skin in the left upper portion of the chest. -if a pacemaker does not function properly, as when the battery wears out, the patient may experience syncope, dizziness, or weakness b/c of an excessively low HR. the pulse ordinally will be less than 60 beats/min b/c the heart is beating without the stimulus of the pacemaker and without the regulation of its own electrical system. the heart tends to assume a fixed slow rate that is not fast enough to allow the patient to function normally. -a patient with a malfunctioning pacemaker should be transported to the ED. when an AED is used, the patched should not be placed directly over the pacemaker.

the pain of AMI (how it differs from the pain of angina)

-it may or may not be caused by exertion but can occur at any time, sometimes when a person is sitting quietly or even sleeping -it does not resolve in a few minutes, it can last b/w 30 minutes and several hours -it may or may not be relieved by rest or nitroglycerin ***not all patients who are having an AMI experience pain or recognize it when it occurs. middle-aged men are likely to minimize their symptoms. some patients, particularly older people, women, and people with diabetes, do not experience any pain during an AMI but have other common complaints associated with ischemia. -others may only feel mild discomfort and call it indigestion. not uncommon for the only complaint, especially in older patients and women, to be fatigue. -EMTs should consider AMI even when the classic symptom of chest pain is not present.

pathophysiology of the cardiovascular system: atherosclerosis

-low blood flow to heart tissue is caused by coronary artery atherosclerosis (disorder in which calcium and a fatty material called cholesterol build up and form a plaque inside the walls of vessels, obstructing flow and interfering with their ability to dilate or contract). -this can cause complete occlusion/ blockage of a coronary artery. -problem begins when the first trace of cholesterol is deposited on the inside of an artery. as a person ages, more of this fatty material is deposited. the lumen/inside diameter of the artery narrows. as the cholesterol deposits grow, calcium deposits can form too. the inner wall of the artery, which is normally smooth and elastic, becomes rough and brittle with these atherosclerotic plaques. -damage to the coronary arteries may become so extensive that they cannot accommodate to increased blood flow during times of maximum need. -a brittle plaque will sometimes develop a crack, exposing the inside of the atherosclerotic wall. acting like a torn BV, the ragged edge of the crack activates the blood-clotting system. this blood clot will partially or completely block the lumen of the artery. if it does not block the artery at that location, the blood clot may break loose and begin floating in the blood, becoming a THROEMBOLISM.

discuss the importance of practice and continuing education with AED

-mandatory continuing education with skill competency review is generally required for EMS providers.

coordination with ALS

-notify the ALS personnel as soon as possible after you recognize a cardiac arrest, but do not delay defibrillation. after the paramedics arrive at the scene, inform them of your actions to that point and then interact with them according to local protocols.

major uncontrollable risk factors for an AMI

-older age -family history of atherosclerotic coronary artery disease -race -ethnicity -male sex

AMI vs Dissecting Aortic Aneurysm

-onset of pain: AMI is gradual, with additional symptoms. DA is abrupt, without additional symptoms -quality of pain: AMI is tightness or pressure. DA is sharp or tearing -severity of pain: AMI increases with time. DA is maximal from onset. -timing of pain: AMI may wax and wane. DA does not abate once it has started -region/radiation: AMI is substernal, back is rarely involved. DA back is possibly involved, b/w the shoulder blades. -clinical signs: AMI peripheral pulses are equal. DA blood pressure discrepancy b/w arms or decrease in a femoral or carotid pulse.

anatomy, physiology, pathophysiology, assessment, and management of acute myocardial infarction

-pain of AMI signals the actual death of cells in the area of the heart muscle where blood flow is obstructed. -once dead, the cells will turn into scar tissue and become a burden to the beating heart. -fast action is critical in treating a heart attack. the sooner the arterial blockage can be cleared, the fewer cells that may die. about 30 mins after blood flow is cut off, some heart muscle cells begin to die. after 2 hours, as many as half the cells in the area can be dead. in most cases after 4-6 hours more than 90% will be dead. -opening the coronary artery with "clot-busting" (thrombolytic) medications or angioplasty (mechanical clearing of the artery) can prevent permanent damage to the heart muscle if done within the first few hours after the onset of symptoms. SO immediate prehospital treatment and transport to the ED are essential. -an AMI is more likely to occur in the larger, thick-walled LV, which needs more blood and oxygen than the RV. -when you are called to a scene where the chief complaint is chest pain, complete a thorough assessment, no matter what the patient says. patient with cardiac risk factors should also be carefully assessed f they have any of the associated symptoms, even if no chest pain is present. any complaint of chest discomfort is a serious matter.

special populations: AED

-pediatric patient with chest pain is not a common call. usually associated with preexisting heart condition usually present since birth. in pediatric situations, see family members or caregivers as a valuable source of info -cardiac arrest in infants and children is usually the result of respiratory failure, not a primary cardiac event. -AEDs are safe to use in infants and children. if the patient is 8 or younger, pediatric-sized pads and dose attenuating system (energy reducer) are preferred. -if the child is b/w 1 month and 1 year of age, a manual defibrillator is preferred to an AED.

indications and contraindications for the use of aspirin and nitroglycerin

-prepare to administer low-dose aspirin and assist with prescribed nitroglycerin. aspirin prevents clots from forming or getting bigger. administer low-dose aspirin according to local protocol. it comes in 81 mg chewable tablets. the recommended dose is 162 mg to 324 mg (2-4 tablets). be sure you have verified that the patient is not allergic to aspirin before you give it. ask the patient if they have a history of internal bleeding such as stomach ulcers, and if so, contact medical control before giving the patient aspirin. -nitroglycerin may help to relieve the pain of angina. it comes in several forms. it relaxes the muscles of blood vessel walls, dilates coronary arteries, increased blood flow and the supply of oxygen to the heart muscle, and decreases the workload of the heart. it also dilated BV in other parts of the body and can sometimes cause low BP and or a severe headache. other side effects: changes in the patient's pulse rate, including tachycardia or bradycardia. SO take the patients BP within 5 mins after each dose. -if the systolic pressure is less than 100 mm Hg, do not give more medication. other contraindications: presence of a head injury, use of erectile dysfunction drugs within the previous 24-48 hours, and the max prescribed dose of nitroglycerin has already been given (usually 3).

SAMPLE history

-provides basic info on the patient's overall medical history. -you will want to determine any signs and symptoms as you can. the more you know the easier it is to identify a particular problem. -ask whether the patient has had the same pain before. if so ask "do you take any medication for the pain" and "do you have any of the medication with you" -if the patient has had a heart attack or angina before, ask whether the pain is similar -make sure you ask about allergies b/c the patient will probably be give medication in the hospital. if the patient is taking meds, determine whether they are prescribed, over the counter, and or recreational drugs.

AED maintence

-read the operator's manual. if your defibrillator does not work on scene you will be asked to show proof that you maintained the defibrillator properly and attended any mandatory in-service sessions. -to avoid a battery that is not charged, many defibrillator companies have built smarter machines that will warn the operator that the battery is unlikely to work. some of the older machines do not have this. -check your equipment, including your AED, daily at the beginning of each shift and exercise the battery as often as the manufacturer recommends. ask the manufacturer for a checklist of items that should be checked daily, weekly, or less often. -if the AED fails while you are caring for the patient, you must report the problem to the manufacturer and the US Food and Drug administration. be sure to follow the appropriate EMS procedures for notifying these organizations.

patient assessment procedures for cardiovascular problems: patient assessment procedures for cardiovascular problems: Reassessment

-repeat primary assessment by checking to see whether the patient's chief complaint and condition have improved or worsened. -vital signs should be reassessed at least every 5 mins or any time significant changes in the patient's condition occur. -monitor the patient with a suspected AMI closely b/c sudden cardiac arrest is always a risk. if cardiac arrest occurs, be ready to begin AED or chest compressions immediately. if an AED is immediately available, use it, if not perform CPR until an AED is ready. -reassess interventions to see whether they are helping and whether the patient's condition is improving. reassessment will determine whether further interventions are indicated or contraindicated. -transport the patient. early, prompt transport to the ED or specialty center is critical so that treatments such as clot-busting meds or angioplasty can be initiated. -do not delay transport to assist with administration of nitroglycerin. the drug can be given en route. -alert the ED staff about the status of your patient's condition and your ETA. follow the instructions of medical control. describe the patient's condition to the ED staff on arrival. -document assessment and treatment of patient. all interventions should be initiated according to protocol. if an intervention required an order from medical control, document the intervention and or medication requested and that prior approval was granted. must be clear in documentation that the patient was reassessed appropriately following any intervention. patient's response to intervention and the time of each intervention must be recorded. -obtain medical control physician's signature showing approval of medication administration.

patient assessment procedures for cardiovascular problems: patient assessment procedures for cardiovascular problems: Secondary assessment

-secondary assessment of a conscious patient with chest pain or discomfort would likely focus on the patient's cardiac and respiratory systems. -physical exam of a patient with chest pain begins with the cardiovascular system. evaluate the patient's circulation by assessing pulses at various locations, and assess skin color, temp, and condition. is the skin cool or moist? how do the mucous membranes look? are they pink, ashen, or cyanotic? are the pulses of equal strength bilaterally? does the patient have any edema in the extremities? these physical findings can help identify poor circulation, which may be caused by failure of the cardiovascular system. -examine the respiratory system for signs of inadequate ventilation. respiratory and cardiovascular systems are closely related, and cardiovascular issues can cause problems with the respiratory system. are the lung sounds clear? wet sounding lungs indicate fluid is being moved into the lungs from the circulatory system, possibly b/c of a problem with the heart. are the breath sounds equal? are the neck veins distended? is the trachea deviated, or is it midline? -measure and record the patient's vital signs, including pulse, respirations, and blood pressure. take blood pressure on both arms it time allows. use a pulse oximetry if available. -pulse oximetry may not give accurate readings if the patient has poor circulation, has been exposed to a toxic chemical, or is in cardiac arrest, but it should be used and the readings noted for all patients with possible cardiac problems. -if you have assess to continuous BP monitoring, be sure to use it, making sure you get an accurate manual BP first. -repeat the vital signs at appropriate intervals, and use the settings on the automatic BP monitoring machine to remind you when it is time to recheck and record vital signs. be sure to note the time that each set of vitals is taken. -in patients with chest pain it is valuable to have a 12-lead ECG tracing from as early as possible after onset of the pain. EMTs may assist with placing electrodes.

pathophysiology of the cardiovascular system: cardiogenic shock

-shock is present when body tissues do not get enough O2, causing body organs to malfunction -in cardiogenic shock, often caused by a heart attack, the problem is that the heart lacks enough power to force the proper volume of blood through the circulatory system. -more commonly found in an AMI that effects the inferior and posterior regions of the LV of the heart b/s it provides circulation to the majority of the body. -can occur immediately or 24 hour after the onset of AMI.

cardiac monitoring

-some EMS systems will allow you to place electrodes, attach the leads, and obtain an electrocardiogram (ECG) tracing prior to transport. -electrodes must be placed in consistent positions on each patient. there are predetermined locations for each electrode. electrodes used in prehospital settings are usually adhesive and have a gel center to aid in skin contact. -artifact refers to an ECG tracing that is a result of interference, such as patient movement, rather than the heart's electrical activity. ***Guiding principles: 1. to maintain correct lead placement, it may occasionally be necessary to shave body hair from the electrode site. do not be fooled by a hairy chest. it may initially appear that you have good skin contact, but the electrode will rise off the skin and stick to the hair. if you must shave it, be very careful to avoid nicking skin. if one is available, it is best to use an electric razor to remove hair, b/c single-blade manual razors irritate the skin and can easily cut a patient. 2. to remove oils and dead tissues from the surface of the skin, rub the electrode site briskly with an alcohol swab before application. wait for the alcohol to dry before applying electrodes or dry it with a quick wipe of a 4 inch by 4 inch gauze pad. this step may need to be repeated if the patient is sweaty as many cardiac patients are. 3. attach the electrodes to the ECG cables before placement. confirm that the appropriate electrode now attached to the cable is placed at the correct location on the patient's chest or limbs (each cable is marked and color coded as to the correct location for placement) 4. once all electrodes are in place, switch on the monitor, and print a sample rhythm strip. if the strip shows any interference (artifact), verify that the electrodes are firmly applied to the skin and the monitor cable is plugged in correctly. -patient movement, including deep breathing or muscle tremor, may cause a wavy baseline or small up and down squiggles on the baseline. these will prevent the ECG from being usable. make sure the patient is supine if possible or in the semi-Fowler position of they are having difficulty breathing. make sure the patients arms are relaxed by their side and that their feet are uncrossed.

signs and symptoms of AMI

-sudden onset of weakness, nausea, and sweating without an obvious cause -chest pain, discomfort, or pressure that is often crushing or squeezing and that does not change with each breath -pain, discomfort, or pressure in the lower jaw, arms, back, abdomen, or neck -irregular heartbeat and syncope (fainting) -shortness of breath/ dyspnea -nausea/ vomiting -pink, frothy sputum (indicating possible pulmonary edema) -sudden death

dangerous dysrhythmias

-tachycardia: rapid beating of the heart, 100 beats/min or more -bradycardia: unusually slow beating of the heart, 60 beats/min or less -ventricular tachycardia: rapid heart rhythm, usually at a rate of 150-200 beats/min. electrical activity starts in the ventricle instead of the atrium. rhythm does not allow adequate time b/w beats for the LV to fill with blood. patient's BP may fall, and the pulse may be lost. patient may feel weak or light headed or may even become unresponsive. existing chest pain may worsen or chest pain that was not there before onset of the dysrhythmia may develop. can deteriorate into ventricular fibrillation -ventricular fibrillation (V fib): disorganized, ineffective quivering of the ventricles. no blood is pumped through the body, and the patient usually become unconscious within seconds. only way to convert this is to defibrillate the heart. *** to defibrillate means to shock the heart with a specialized electric current in an attempt to stop the chaotic, disorganized contraction of the myocardial cells and allow them to start again in a synchronized manner to restore a normal rhythmic beat. if a defibrillator is not available, CPR must be initiated until the defibrillator arrives.

explain the reason not to touch the patient, such as by delivering CPR, while the AED is analyzing the heart rhythm and delivering shock

-the AED may not be able to distinguish other movements from ventricular fibrillation. SO apply the AED to only pulseless, unresponsive patients and stay clear of the patient (do not touch them) while the AED is analyzing the heart rhythm and delivering shocks. -stop CPR and let the AED do its job

explain the circumstances that may result in inappropriate shocks from an AED and common errors

-the AED may not be able to distinguish other movements from ventricular fibrillation. SO apply the AED to only pulseless, unresponsive patients and stay clear of the patient (do not touch them) while the AED is analyzing the heart rhythm and delivering shocks. -stop CPR and let the AED do its job -main legal risk in using the AED is failing to deliver shock when one was needed. 3 most common errors: failure of the machine to shock fine V fib, applying the AED to a patient who is moving or squirming or being transported, and turning off the AED before analysis or shock is complete. also failure due to a battery that did not work. -operator errors include: failing to apply the AED to a patient in cardiac arrest, not pushing the analyze or shock buttons when the machine advises you to do so, or pushing the power button instead of pushing the shock button when a shock is advised. -error can also occur when the AED is applied to a responsive patient with a rapid heart rate. most AEDs identify a regular rhythm faster than 150 or 180 beats/min as ventricular tachycardia, which should be shocked. sometimes a patient has another heart rhythm that should be shocked but that is fast enough to confuse the computer. to avoid this, only apply an AED to an unresponsive patient with no pulse.

cardiac output

-the amount of blood pumped out of the LV in 1 min -to obtain an accurate measure of the efficiency of the heart, we have to measure the volume of blood pumped and the heart rate. this is determined by calculating the cardiac output. cardiac output is calculated by multiplying the HR by the stroke volume. -this is the volume of blood that passes through the heart in 1 minute and is the best measure of the output of the heart. -in the field there is no way of directly measuring the volume of blood being pumped, so we must rely on the HR and the strength of the pulse to estimate the cardiac output.

cardiac arrest

-the death of a heart muscle can lead to sever diminishment of the heart's ability to pump or cause it to stop completely

if an ALS service is not responding to the scene and your local protocols agree, you should begin transport when one of the following occurs:

-the patient regains a pulse -6 to 9 shocks have been delivered -the machine gives 3 consecutive messages (separated by 2 minutes of CPR) that no shock is advised

explain the use of remote adhesive defibrillator pads

-the shock can be given through remote, adhesive defibrillator pads. the pad area is larger than manual paddles, which means that the transmission of electricity is more efficient. -usually there are pictures on the pads to remind you where they go on the patient's chest. -make sure the patient is not lying on wet ground or touching metal objects when the patient is being shocked.

stroke volume

-the volume of blood pumped out by the LV in one contraction. affected by preload, afterload, and contractility. -preload: related to the venous return to the RA -afterload: associated with systemic vascular resistance, which is a function of the constriction of the systemic blood vessels. as the BV constrict, it is harder for the ventricle to pish the blood into them. -contractility refers to how forcefully the heart contracts

list quality improvement goals related to AEDs

-there should also be a review of the incident by your service's medical director or quality improvement officer. quality improvement involves people using AEDs and the responsible EMS system management. this review should focus on speed of defibrillation, the time from the call to the shock. the ultimate goal is shock 100% of patients within 1 minute of the call. all systems continuously work on improving patient care.

explain the need for a case review of each incident in which an AED is used

-there should be a review of each incident in which the AED is used. after returning from the hospital or the scene, discuss with the rest of the team what happened. this will help all members of the team learn from the incident. review such events by using the written report and the devices recordings. -there should also be a review of the incident by your service's medical director or quality improvement officer. quality improvement involves people using AEDs and the responsible EMS system management. this review should focus on speed of defibrillation, the time from the call to the shock. the ultimate goal is shock 100% of patients within 1 minute of the call. all systems continuously work on improving patient care.

different types of AEDs

-they come in different models with different features. -many AEDs use a computer voice synthesizer to advise the operator which steps to take on the basis of the AED's analysis. -some have a button that tells the computer to analyze the heart's electrical rhythm. other models start doing this as soon as they are turned on. -most are semiautomated.

anatomy and physiology of the cardiovascular system: circulation

-to carry out its function of pumping blood, the myocardium/ heart muscle must have a continuous supply of oxygen and nutrients. during periods of physical exertion/stress the myocardium requires more O2. heart muscle must increase cardiac output to meet the increased metabolic requirements of the body. -cardiac output is increased by increasing the heart rate or stroke volume: the volume of blood ejected with each ventricular contraction. -in a normal heart, increased O2 demand of the myocardium itself is supplied by dilation of the coronary arteries, which increases blood flow. coronary arteries are the BV that supply blood to the heart muscle. they start at the first part of the aorta, just above the aortic valve. the right coronary artery supplies blood to the RA and RV and in most people, the bottom part or inferior wall of the LV. the left coronary artery supplies blood to the LA and LV and divides into two major branches, just a short distance from the aorta. -after blood travels through the arteries, it enters smaller and smaller vessels called arterioles and eventually enters the capillaries (tiny blood vessels about one cell thick that connect arterioles to venules). capillaries are found in all parts of the body and they allow the exchange of nutrients and waste at the cellular level. -venules are the smallest branches of veins. after traveling through capillaries, oxygen-poor blood enters the systems of veins, starting with the venules, on its way back to the heart. the veins become larger and larger and eventually form the two large venae cavae: the superior and inferior. -the superior vena cava carries blood from the head and arms back to the RA. the inferior vena cava carries blood from the abdomen, kidneys, and legs back to the RA. they join at the RA of the heart, where blood is returned into the pulmonary circulation for oxygenation. -rate of cardiac contractions can be increased or decreased by the ANS. the heart has the ability to increase or decrease the volume of blood it pumps which each contraction based on the ANS response.

how to provide emergency medical care for chest pain or discomfort

-treatment begins with proper positioning. some patients will not tolerate being positioned supine, so they should be allowed to sit up (leaning back on the stretcher). -loosen tight clothing, trying to make the patient comfortable -if it is indicated, you should be giving the patient O2 by this time, but continually reassess the O2 saturation and patient's respiratory status. -for patients with mild dyspnea, a nasal cannula may be all that is needed BUT patients with more serious respiratory difficulty may require a nonrebreathing mask. remember to titrate the O2 to obtain an oxygen saturation b/w 95% to 99%. -a patient who is unconscious or in obvious respiratory distress may need assistance with breathing. use a BVM or another positive-pressure ventilation device if available and if you have been approved to use it in your service. consider CPAP depending on local protocol. be aware that ALS may be needed to support the use of positive end- expiratory pressure, CPAP, bilevel positive airway pressure, and transport ventilators. -prepare to administer low-dose aspirin and assist with prescribed nitroglycerin.

branching arteries

-two major arteries branching from the upper aorta supply blood to the head and arms. the right and left carotid arteries supply the head and brain with blood. the right and left subclavian arteries supply to the upper extremities. as the subclavian artery enters each arm, it becomes the brachial artery, the major vessels that supplies blood to each arm. just below the elbow, the brachial artery divides into two major branches: the radial and ulnar arteries, supplying blood to the lower arms and hands. -@ the level of the umbilicus, the descending aorta divides into 2 main branches called the right and left iliac arteries, which supply blood to the groin, pelvis, and legs. as the iliac arteries enter the legs through the groin, they become the right and left femoral arteries. at the level of the knee, the femoral artery divides into the anterior and posterior tibial arteries and the peroneal artery, supplying blood to the lower legs and feet.

explain the relationship b/w airway management and the patient with cardiac compromise

-unless the patient is unresponsive, the airway will most likely be patent. responsive patients should be able to maintain their own airway. some episodes of cardiac compromise may produce dizziness or even fainting spells (syncope). if dizziness or fainting has occurred, consider the possibility of a spinal injury from a fall. assess and treat the patient as appropriate. -assess the patient's breathing to determine if is adequate to provide enough O2 to an ailing heart. if the rate is too fast or slow, the depth of respiration seems to be too shallow, or the patient is struggling to breathe, respirations are inadequate. -patients experiencing pulmonary edema may require positive pressure ventilation with a BVM or CPAP. -CPAP is the most effective way to assist a person with CHF to breathe effectively and prevent an invasive airway managing technique. -changes in perfusion may indicate more serious cardiac compromise

discuss the emergency medical care for the patient with cardiac arrest: preparation

-when dispatch reports an unresponsive patient with CPR being performed, the AED is probably one of the first pieces of equipment you will obtain from the ambulance. -as the operator of the AED, you are responsible for making sure the electricity does not injure anyone, including yourself. remote defibrillation using pads allows you to distance yourself safely from the patient. as long as you place the pads in the correct position and make sure no one is touching the patient, you should be safe. -do not defibrillate a patient who is pooled in water. electricity follows the path of least resistance, instead of traveling b/w the pads and through the patients heart, it will diffuse into the water. the heart will not receive enough electricity to cause defibrillation. -you can defibrillate a soaking wet patient, but try first to dry the patient's chest. do not defibrillate someone who is touching metal that others are touching, and carefully remove a nitroglycerin patch from a patient's chest and wipe the area with a dry towel before defibrillation to prevent ignition of the patch. it is helpful to shave a hairy patient's chest before pad placement to increase conductivity. -determine the NOI and or MOI. if the incident involves trauma, consider spinal immobilization as you begin the primary assessment. is there only one patient? if you are in a tiered system and the patient is in cardiac arrest, call for ALS. if you suspect the patient is in cardiac arrest, discuss who will perform which resuscitation responsibilities prior to arrival on the scene.

patient assessment procedures for cardiovascular problems: scene size up

-while en route to the scene, consider the standard precautions that will be needed. the precautions can be as simple as gloves for a patient with chest pain or full precautions for a patient in cardiac arrest -always ensure that the scene is safe for all. look for and address any hazards. determine the necessary and standard precautions and whether you will need additional resources. -identification of the NOI is important to start your patient assessment. -use the info you get from the dispatcher, clues at the scene, and comments of bystanders or family members to begin to develop an idea about the type of problem the patient might be experiencing. -for patients with cardiac problems, the clues often include a report of chest pain, difficulty breathing, or sudden loss of consciousness. -once you establish a preliminary NOI you will be able to guide your assessment to find the important info much more effectively.

common pulse points

1. carotid pulse is felt in the neck 2. femoral pulse is felt in the groin 3. brachial pulse is felt on the inside of the upper arm 4. radial pulse is felt on the thumb side of the wrist 5. the posterior tibial pulse is felt on the inside of the ankle 6. the dorsalis pedis pulse is felt on the top of the foot

if you are en route with a conscious patient who is having chest pain and become unconscious, take the following steps

1. check for pulse 2. stop the vehicle 3. if the AED is not ready perform CPR until it is 4. analyze the rhythm 5. deliver a shock if indicated, and resume CPR 6. begin compressions, and continue resuscitation accord to local protocol, including transporting the patient

physical findings of AMI and cardiac compromise

1. general appearance: patient often appears frightened. there may be nausea, vomiting, and a cold sweat. the skin if often pale or ashen gray b/c of poor cardiac output and the loss of perfusion, or blood flow through the tissue. the skin may have a bluish tint (cyanosis), the result of poor oxygenation of the circulating blood. 2. pulse: generally pulse rate increases as a normal response to pain, stress, fear, or actual injury to the myocardium. dysrhythmias are common in an AMI so you may feel an irregularity or even a slowing of the pulse. pulse may be dependent on the area of the heart that has been affected by the AMI. damage to the inferior area of the heart often presents with bradycardia. 3. blood pressure: may fall as a result of diminished cardiac output and diminished capability of the LV to pump. most patients with an AMI will have a normal, or possibly elevated BP. 4. respiration: RR is usually normal until the patient has CHF. then the respirations may become rapid and labored with a higher likelihood of cyanosis and possibly frothy sputum. a complaint of difficulty breathing is common with cardiac compromise, so even if the rate seems normal, look at the work of breathing and treat the patient as if respiratory compromise were present. 5. mental status: often experience confusion or agitation and sometimes an almost overwhelming feeling of impending doom.

demonstrate the use of an AED

1. if bystander CPR is in progress, assess the effectiveness of chest compressions by palpating for a carotid or femoral pulse. if compressions are effective, you should be able to feel a pulse. if you do, leave your fingers in that position and stop compressions. if you lose the pulse when compressions stop, resume them. it is important to limit the amount of time compressions are interrupted. if the patient is responsive, do not apply the AED. 2. if the patient is unresponsive and CPR has not been started yet, begin providing chest compressions and rescue breaths at a ratio of 30 to 2 breaths and a rate of 100-120 compressions per minute, continuing until the AED arrives and is ready for use. important to start compressions and use the AED ASAP. compressions provide vital blood flow to the heart and brain, improving the patient's chance of survival. high quality compressions provide the best cardiac output. 3. turn on the AED. remove clothing from the patient's chest area. apply the pads on the chest: one just to the right of the breastbone/sternum just below the collarbone/ clavicle, the other on the left lower chest area with the top of the pad 2 inches to 3 inches below the armpit. do not place the pads on top of breast tissue in women. move the breast out of the way with the back of your hand and place the pad underneath. ensure that the pads are attached to the patient cables. plug in the pads connector to the AED. 4. stop CPR when the AED instructs you to 5. state aloud "clear the patient' and ensure that no one is touching the patient. 6. push the analyze button, if there is one, and wait for the AED to determine whether a shockable rhythm is present. if a shock is advised, perform chest compressions while the AED is charging. 7. if a shock is not advised, perform 5 cycles of CPR, beginning with chest compressions, and then reanalyze the cardiac rhythm. if a shock is advised, reconfirm that no one is touching the patient and push the Shock button. if at any time the AED advises to check the patient, quickly assess for a carotid or femoral pulse. this should take no longer than 5-10 seconds. if you feel a pulse, the patient has experience return of spontaneous circulation. ROSC is defined as the return of a pulse and effective blood flow to the body in a patient who previously was in cardiac arrest. continue to monitor them. 8. after the shock is delivered, resume CPR beginning with chest compressions. remember to change to a different person for chest compressions each time CPR is paused to prevent rescuer fatigue. 9. after 5 cycles of CPR, reanalyze the patient's cardiac rhythm. do not interrupt chest compressions for more than 10 seconds. 10. if the AED advises shock, clear the patient, push the Shock button, and resume CPR compressions. if no shock is advised, resume CPR with chest compressions and remember to change the person providing compressions. 11. gather additional info about the arrest event 12. after 5 cycles of CPR, reassess the patient 13. repeat the cycle of 2 minutes of CPR, one shock if indicated, and 2 minutes of CPR 14. transport, and contact medical control as needed

steps to assist the patient with nitroglycerin

1. obtain an order from medical control (online or through off-line protocol) 2. take the patient's BP. administer nitroglycerin only if the systolic BP is greater than 100 mm Hg. 3. check that you have the right medication, the right patient, and the right deliver route. check the expiration date. make sure the patient has no contraindications, such as having taken medication for erectile dysfunction in the past 24 hours. 4. ask the patient about the last dose they took and its effects. make sure that the patient understands the route of administration. be prepared to have the patient lie down to prevent fainting if the nitroglycerin substantially lowers the patient's BP (patient gets dizzy or feels faint) 5. ask the patient to lift their tongue. place the tablet or spray under the tongue (while wearing gloves), or have the patient do so. have the patient lower the tongue and keep their mouth closed with the tablet or spray under the tongue until it is dissolved and absorbed. caution the patient against chewing or swallowing the tablet. 6. recheck the BP within 5 minutes. record the medication and the time of administration. reevaluate the chest pain, and note the response to the medication. if the chest pain persists and the patient still has a systolic BP greater than 100 mm Hg, repeat the dose every 5 minutes as authorized by medical control. a max of three doses is given for any one episode of chest pain.

chain of survival is a way of describing the ideal sequences of events that can take place when sudden cardiac arrest occurs

1. recognition of early warning signs and immediate activation of EMS 2. immediate CPR with emphasis on high quality chest compressions 3. rapid defibrillation 4. basic and advanced EMS 5. ALS and postarrest care

consequences of AMI

1. sudden death 2. cardiogenic shock 3. congestive heart failure

demonstrate how to attach a cardiac monitor to obtain an ECG

1. take standard precautions 2. explain the procedure to the patient. prepare the skin for electrode placement. 3. attach the electrodes to the leads before placing them on the patient 4. position the limb electrodes on the patient, on the torso if performing continuous monitoring, on the limbs if you will be acquiring a 12-lead ECG. the RA electrode goes on the right arm distal to the shoulder or on the wrist (avoid placing it directly over a bone). the LA electrode goes on the left arm at the same location as the RA. the LL electrode is placed on the left leg on the thigh or ankle, although if you do not plan to obtain a 12-lead ECG tracing, this electrode is often placed on the lower left side of the abdomen (slightly lower than the AED pad would be placed). place the RL electrode at the same location on the right side of the body as the LL on the left. 5. if you plan to obtain a 12-lead ECG tracing, place the chest leads on the chest as shown. The v1 is placed on the right side of the sternum b/w the 4th and 5th ribs. the v2 electrode is placed on the left side of the sternum directly across from the v1. v4 is placed next, b/w the 5th and 6th ribs in a straight line down from the middle of the clavicle. the v3 is placed halfway b/w the v2 and v4. the v6 is placed next and is located horizontally even with v4 in a straight line down from the middle of the armpit. v5 is placed halfway b/w v4 and v6. 6. turn on the monitor 7. record tracings. as soon as a rhythm is visible on screen, press the print button on the monitor and print a strip while counting slowly to six or seven. then press the print button again to stop the printout. if the time is not printed correctly on the strip, write it on the edge of the strip. if you are obtaining a 12-lead ECG tracing, ask the patient to hold their breath or to take very shallow breaths. press the 12-lead button and wait for the machine to acquire, analyze, and print or transmit the 12-lead ECG tracing. gently tear off the tracing when the printer automatically stops. 8. label each strip.

words of wisdom for documentation

documenting exactly how a patient describes chest discomfort, in the patients own words, is a valuable source of info for hospital staff.

infarction

infarction means the death of tissue.

heart rate

the number of times the heart contracts in 1 min