MODULE 4 CARING FOR THE PATIENTS WITH SHOCK
Metabolic Alterations caused by Shock: What happens when lipolysis occurs?
As shock progresses, adipose tissue is broken down (lipolysis) for energy production. Fat metabolism result in lactate production and acidosis
What should you assess for during a psychosocial Assessment for shock?
Changes in mental status and behavior occur early in shock: ₋ Assess mental status by evaluating LOC and noting whether the patient is asleep or awake. ₋ If the patient is asleep, attempt to awaken him or her and document how easily he or she is aroused. ₋ If the patient is awake, determine whether he or she is oriented to person, place, and time. ₋ Avoid asking questions that can be answered with a "yes" or a "no" response.
Nonsurgical Management: IV Therapy What are crystalloids and colloids used for?
Crystalloids and colloids are often used for volume replacement. o Colloid solutions contain large molecules of proteins or starches o Crystalloid solutions contain nonprotein substances (e.g., minerals, salts, sugars). o Colloid solutions contain large molecules of proteins or starches: ••• Two common solutions are normal saline and Ringer's lactate: ₋ Normal saline (0.9% sodium chloride in water) is a replacement solution used to increase plasma volume and can be infused with any blood product. ₋ Ringer's lactate contains sodium, chloride, calcium, potassium, and lactate. This isotonic solution expands volume, and the lactate buffers acidosis. o To date, no research has shown one type of crystalloid solution to be better than another overall. o Selection of specific fluid is based on the patient's fluid and electrolyte status, acid-base status, and organ function
Nonsurgical Management: Drug Therapy How do vasodilators act and what do they do to the body?
Decreasing the workload of the left ventricle. It reduces SVR and LVEDP in an effort to increase CO and improve left ventricular function.
Nonsurgical Management: Drug Therapy How do sympathomimetic drugs act and what do they do to the body?
(Vasoconstrictors)—may enhance CO by increasing contractility, heart rate, or SVR but simultaneously increase cardiac work.
Shock is characterized by which metabolic alterations?
- Anaerobic metabolism - Excessive catecholamine - insulin resistance - lipolysis
What alterations does shock lead to?
- Cardiovascular Alterations - Pulmonary Alterations - Hematologic Alterations - Metabolic Alterations
What are the learning outcomes for this module?
- Collaborate with the interprofessional team to coordinate high quality care and promote PERFUSION in patients who are experiencing shock. ₋ Teach adults how to decrease the risk for sepsis and shock. ₋ Implement nursing interventions to help the patient and family cope with the psychosocial impact caused by shock or its complications. ₋ Apply knowledge of anatomy and physiology to assess critically ill patients with respiratory problems affecting PERFUSION or IMMUNITY. ₋ Implement evidence-based nursing interventions to prevent complications of sepsis and shock.
Shock Assessment: - History: What risk factors should you ask about that relate to hypovolemic shock?
- If the patient is alert, question him or her directly. ₋ If the patient is not alert, collect information from family members.: ••• Ask about recent illness, trauma, procedures, or chronic health problems that may lead to shock (e.g., GI ulcers, general surgery, hemophilia, liver disorders, prolonged vomiting or diarrhea). ••• Ask about the use of drugs such as aspirin, other NSAIDs, and diuretics that may cause changes leading to hypovolemic shock. ••• Ask about fluid intake and output during the previous 24 hours. ••• Information about urine output is especially important because urine output is reduced during the first stages of shock, even when fluid intake is normal.
What occurs during Multiple Organ Dysfunction Syndrome (MODS)?
- In MODS, dysfunction, and the inflammatory response in one organ may trigger dysfunction in another. Therefore, failure of a particular organ makes the failure of a second or third organ more likely. ₋ Usually, the first organs to manifest signs of dysfunction are the lungs, heart, and kidneys. If hypoperfusion persists, all vital organs may fail.
What are the shock statistics?
- In the United States, sepsis results in over a million hospitalizations annually. ₋ Mortality increases dramatically with the severity of illness. Sepsis, severe sepsis, and septic shock are associated with mortality rates of 16%, 25%, and 50% respectively. ₋ Early recognition and treatment have a major impact on patient outcomes. ₋ Approximately one in four patients who present to the emergency department in sepsis will progress to septic shock within 72 hours. ₋ For patients who become hypotensive in the emergency department, each hour delay in the administration of antibiotics increases their mortality by 7%. ₋ Septic shock is a complex and generalized process that involves all organ systems. ₋ Sepsis, severe sepsis, and septic shock represent progressive stages of the same illness in response to infection.
Multiple Organ Dysfunction Syndrome (MODS): What happens during neurologic dysfunction that occurs during MODS?
- It can be manifested by altered levels of consciousness, confusion, and delirium. - The dysfunction may be secondary to poor cerebral perfusion or an increase in metabolic substances that are neurotoxic (ammonia), or it can be due to electrolyte imbalances.
Shock Physical Assessment: What Signs and Symptoms should you assess for?
- Most signs and symptoms of hypovolemic shock are caused by the changes resulting from compensatory efforts. ₋ Shock may first be evident as changes in cardiovascular function. ₋ As shock progresses, changes in the renal, respiratory, integumentary, musculoskeletal, and central nervous systems become evident. ₋ Ensure that vital sign measurements are accurate and monitor them for trends indicating shock. ₋ Assess the patient for factors that can lead to shock. Areas to examine for poor CLOTTING and hemorrhage include the gums, wounds, and sites of dressings, drains, and vascular accesses. ₋ Also check under the patient for blood. ₋ Observe for any swelling or skin discoloration that may indicate an internal hemorrhage.
Distributive Shock: What could the loss of blood vessel tone be due to?
- Neural Induced - Chemical-Induced: o Anaphylaxis o Sepsis o Capillary Leak Syndrome
What are forms of Nonsurgical Management?
- Oxygen Therapy - IV Therapy - Drug Therapy - Monitoring vital signs and level of consciousness
What does the combination of intravascular coagulation and decreased circulating blood volume result in?
- Results in reduced perfusion of vital organs, which can progress to multiple organ dysfunction syndrome (MODS) and death
Nonsurgical Management: Drug Therapy What drugs types are used for shock?
- Sympathomimetic drugs - Inotropic Agents - Vasodilators - N.B. Sympathomimetic
What is SIRs manifested by?
- The SIRS is manifested by two or more of these conditions: o Temperature greater than 38°C or less than 36°C (greater than 100.4°F or less than 96.8°F) o Heart rate more than 90 beats/min o Respiratory rate more than 20 breaths/min or PaCO2 less than 32 mm Hg o WBC count greater than 12,000 cell/mm3 or less than 4,000 cells/mm3 . *Any of these manifestations especially in patients who are at risk for shock (e.g. patients in ICU and postoperative patients) should alert the nurse that the patient might be in shock and SIRS.*
What happens during the Non progressive stage?
- The nonprogressive stage of shock occurs when MAP decreases by 10 to 15 mm Hg from baseline. ₋ Kidney and hormonal compensatory mechanisms are activated because cardiovascular responses alone are not enough to maintain MAP and supply oxygen to vital organs. ₋ As a result, urine output decreases, sodium and water retention, and widespread blood vessel constriction occurs. ₋ Together these actions compensate for shock by maintaining the fluid volume within the central blood vessels. ₋ Tissue hypoxia occurs in nonvital organs (e.g., skin, GI tract) and in the kidney, but it is not great enough to cause permanent damage. ₋ Buildup of metabolites from anaerobic metabolism causes acidosis (low blood pH) and subsequently increased blood potassium levels. - If the patient is stable and compensatory mechanisms are supported by interventions, he or she can remain in this stage for hours without having permanent damage. ₋ Stopping the conditions that started shock and providing supportive interventions can prevent the shock from progressing. ₋ The effects of this stage are reversible when nurses recognize the problem and coordinate the interprofessional health care team to start appropriate interventions.
Nonsurgical Management: IV Therapy What are protein-containing colloid fluids used for?
- help restore osmotic pressure and fluid volume. o Blood products are used when shock is caused by blood loss. (PLASMA AND PRBCs)
Nonsurgical Management: IV Therapy What are PRBC's used for?
- help restore osmotic pressure and fluid volume. o Blood products are used when shock is caused by blood loss. ₋ PRBCs increase hematocrit and hemoglobin levels along with some fluid volume. ₋ Massive transfusion therapy, defined as 10 units of PRBCs given within the first 6 hours of severe hemorrhage, can improve outcomes and prevent death from acute traumatic coagulopathy.
Nonsurgical Management: IV Therapy What is plasma used for?
- help restore osmotic pressure and fluid volume. o Plasma, an acellular blood product containing clotting factors, is given to restore osmotic pressure when hematocrit and hemoglobin levels are normal. ₋ Plasma protein fractions (e.g., Plasmanate) and synthetic plasma expanders (e.g., hetastarch [hydroxyethyl starch, Hespan]) increase volume and are used for hypovolemic shock before a cause is identified.
What is the pathophysiology of shock?
- hypoperfusion, hypercoagulability, and activation of the inflammatory response, are common to all shock states. ₋ Once a shock state develops, the subsequent course of illness is less dependent on the initial cause and more significantly influenced by the physiologic response to shock, including the activation of: ooo The sympathetic nervous system ooo The inflammatory response ooo The immune system ooo Coagulation cascade. ₋ Thus, shock can be considered as a derangement of compensatory mechanisms that results in further circulatory and respiratory dysfunction with subsequent multiple organ damage. ₋ During shock states, oxygen is consumed at a much greater rate than it is delivered. Oxygen supply is insufficient to meet oxygen demand, resulting in cellular hypoxia and dysfunction. ₋ Initial compensatory mechanisms by the respiratory, endocrine, and circulatory systems respond to the cells' need for oxygen by increasing oxygen delivery through increasing in heart rate, systemic vascular resistance (SVR), preload, and cardiac contractility. ₋ If the compensatory mechanisms failed and oxygen availability continues to be insufficient to meet cellular demands for energy, cell death ensues. As more cells die, tissues and organs become progressively dysfunctional.
Metabolic Alterations caused by Shock: What is catecholamine and what does excessive amounts of it cause?
- neurotransmitters.... epinephrine, norepinephrine, dopamine released by the adrenal cortex - stimulates hepatic gluconeogenesis (Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrates) and insulin resistance. - This compromises cellular metabolism, causing hyperglycemia in patients with shock who do not have diabetes.
What is distributive shock?
- occur due to loss of blood vessel tone - blood vessel dilation = pooling of blood in venous and capillary beds - increased capillary leak resulting in the distribution of blood volume to the interstitial tissues where it cannot perfuse organs.
What compensatory mechanism happens when renal perfusion decreases during shock?
-- Decreased renal perfusion would result in the activation of the Renin-angiotensin aldosterone mechanism: ••• The kidney will release renin to stimulate angiotensin I. Angiotensin I is converted to angiotensin II by the Angiotensin Converting Enzyme. ••• Angiotensin II causes vasoconstriction increasing SVR and blood pressure. It also stimulates the adrenal cortex to release aldosterone which results in sodium and water retention and subsequent increase in cardiac output.
Nonsurgical Management: Drug Therapy How do Inotropic Agents act and what do they do to the body?
Directly stimulate beta-adrenergic receptors on the heart muscle, improving contractility
Distributive Shock: What is chemical induced blood vessel tone loss?
Due to vasodilating substances in the blood such as in case of: o Anaphylaxis o Sepsis o Capillary Leak Syndrome
What cardiovascular alterations happen early in shock?
Early in shock, activation of the sympathetic nervous system and release of vasodilatory substances such as NO promote development of a hyperdynamic state, with a resulting increased heart rate, contractility and CO.
Nonsurgical Management: What is hemodynamic monitoring?
Hemodynamic monitoring in critical care settings includes: o Central Venous Pressure Monitoring o Intra-arterial Monitoring o Mixed Venous Oxygen Saturation (SvO2) o Pulmonary Artery Monitoring o Pulmonary Capillary Wedge Pressures.
Nonsurgical Management: Drug Therapy What are examples of sympathomimetic drugs?
High dose Dopamine, Epinephrine & Norepinephrine (Levophed)
What compensatory mechanism happens when you are hypoxic during shock?
Hypoxic states activate respiratory compensatory mechanisms that increase the depth and rate of respirations.
Metabolic Alterations caused by Shock: What happens in Anaerobic Metabolism?
If the compensatory mechanisms failed to provide the cells with the required oxygen, cells resort to anaerobic which produces lactate as a by-product; this can result in systemic metabolic acidosis which further increased hypoxia.
What is disseminated intravascular coagulation (DIC)?
Is a condition in which small blood clots develop throughout the bloodstream, blocking small blood vessels. The increased clotting depletes the platelets and clotting factors needed to control bleeding, causing excessive bleeding.
Distributive Shock: What is Capillary Leak Syndrome (chemical induced) blood vessel tone loss?
Is the response of capillaries to the presence of histamine and other chemicals that enlarge capillary pores and allow fluid to shift from the capillaries into the interstitial tissues
Nonsurgical Management: Drug Therapy How do N.B. Sympathomimetic drugs act and what do they do to the body?
N.B. Sympathomimetic drugs mimic the effects of sympathetic activation on the heart and circulation. Like the sympathetic nerves innervating the heart, sympathomimetics stimulate the heart through activation of beta-adrenoceptors, and sympathomimetics cause vascular smooth muscle contraction and vasoconstriction through activation of alpha-adrenoceptors.
Nonsurgical Management: How is oxygen therapy used?
Oxygen therapy is used at any stage of shock and is delivered by mask, hood, nasal cannula, endotracheal tube, or tracheostomy tube.
What is shock?
Shock can best be defined as a condition in which tissue perfusion (Blood flow to tissues) is inadequate to deliver oxygen and nutrients to support vital organs and cellular function.
Nonsurgical Management: Drug Therapy What are examples of vasodilators?
Sodium nitroprusside (Nipride), nitroglycerin
What is the net effects of these metabolic derangements?
The net effect of these metabolic derangements is that cells become energy starved. This energy deficit is implicated in the emergence of multiple organ failure that frequently develops regardless of interventions designed to support the circulatory and organ systems.
What occurs with systemic inflammatory response syndrome (Sirs)?
The result is an overwhelming, unregulated inflammation with uncontrolled coagulation, disruption of capillaries and intravascular volume loss, and imbalance between cellular oxygen supply and demand.
What are the stages of shock?
The syndrome of shock progresses in four stages when the conditions that cause shock remain uncorrected and poor cellular oxygenation continues. These stages are: 1. Initial stage 2. Non Progressive stage 3. Progressive stage 4. Refractory stage
Nonsurgical Management: Drug Therapy What are examples of Inotropic agents?
low-dose dopamine, Dobutamine (Dobutrex), Amrinone, Milrinone
What pulmonary alterations occur with shock?
o Activation of the sympathetic nervous system and release of epinephrine from the adrenal medulla cause bronchodilation. However, inflammatory cytokines override the effect of epinephrine, and the net result is bronchoconstriction. o Vasodilatation results in increased capillary permeability causing capillary leak into the pulmonary interstitium, resulting in interstitial edema and fluid filled alveoli with resulting impaired gas exchange and hypoxemia. o The pulmonary alterations may culminate in acute respiratory distress syndrome (ARDS), which is frequently associated with septic shock. o Also, Mechanical ventilation, which is common in patients with ARDS, may provide an avenue of entry for microorganisms into the lungs. Therefore, a secondary pneumonia may develop, possibly caused by a different organism than that which produced the sepsis.
Distributive Shock: What is Anaphylaxis (chemical induced) blood vessel tone loss?
o Anaphylaxis is an extreme type of allergic reaction. ₋ It begins within seconds to minutes after exposure to a specific allergen in a susceptible adult. ₋ The result is widespread loss of blood vessel tone, with decreased blood pressure and cardiac output
Shock Physical Assessment: What skin COLOR changes occur with shock?
o Color changes appear first in oral mucous membranes and in the skin around the mouth. ••• In dark-skinned patients, pallor or cyanosis is best assessed in the oral mucous membranes. ••• Other color changes are noted first in the skin of the extremities and then in the central trunk area. o As shock progresses, skin becomes mottled. ••• Lighter-skinned patients have an overall grayish-blue color; and darker-skinned patients appear darker, without an underlying reddish glow.
Shock Physical Assessment: What skin color changes occur with capillary refill during shock?
o Evaluate capillary refill time by pressing on the patient's fingernail until it blanches and then observing how fast the nail bed resumes color when pressure is released. •••Normally capillaries resume color as soon as pressure is released. ••• With shock, capillary refill is slow or may be absent. ••• *Capillary refill is not a reliable indicator for peripheral blood flow in older patients or those with anemia, diabetes, or peripheral vascular disease.*
Nonsurgical Management: How is Drug therapy used?
o Is used in addition to fluid therapy when volume loss is severe, and the patient does not respond sufficiently to fluid replacement and blood products. • Drugs for shock increase venous return, improve cardiac contractility, and improve cardiac PERFUSION by dilating the coronary vessels.
Distributive Shock: What is neural induced blood vessel tone loss?
o Loss of sympathetic innervation to blood vessels (such as in neurogenic shock) o Problems leading to loss of sympathetic tone include Pain, Anesthesia, Stress, Spinal cord injury & Head trauma
What vasodilating substances are released and what does it cause? (Inflammatory response)
o Nitric oxide (NO), histamine, and bradykinin o It increases capillary permeability causing widespread extravasation of fluid into the interstitial compartment.
Nonsurgical Management: What vital signs should the nurse monitor?
o Pulse (rate, regularity, and quality) o Blood pressure o Pulse pressure o Central venous pressure (CVP) o Respiratory rate o Skin and mucosal color o Oxygen saturation o Cognition o Urine output *Assess these parameters at least every 15 minutes until the shock is controlled and the patient's condition improves.*
What does the activation of the inflammatory response cause?
o Release of vasodilating substances o Systemic activation of the coagulation cascade. perfusion by obstructing blood flow. o Over time, clotting factors are depleted, and a coagulopathy occurs, with the potential of progressing to disseminated intravascular coagulation (DIC).
Non Progressive Stage: What are the signs and symptoms of this stage include changes resulting from decreased tissue perfusion?
o Subjective changes include thirst and anxiety. o Objective changes include restlessness, tachycardia, increased respiratory rate, decreased urine output, falling systolic blood pressure, rising diastolic blood pressure (due to vasoconstriction), narrowing pulse pressure, cool extremities, and a 2% to 5% decrease in oxygen saturation. o Comparing these changes with the values and observations obtained earlier is critical to identifying this stage of shock.
Shock Physical Assessment: What skin Temperature changes occur with shock?
o With shock, it feels cool or cold to the touch and is moist. ••• The skin feels clammy or moist to the touch, not because sweating increases but because the normal fluid lost through the skin does not evaporate well on cool skin.
What early manifestations should the nurse assess for in hypovolemic shock?
• Assess all patients with invasive procedures or trauma for obvious or occult bleeding from impaired CLOTTING. • Compare pulse quality and rate with baseline. • Compare urine output with fluid intake. • Check vital signs of patients who have persistent thirst. • Assess for shock in any patient who develops a change in mental status, an increase in pain, or an increase in anxiety. • Teach patients who have invasive procedures about the signs and symptoms of shock. **Stress the importance of seeking immediate help for obvious heavy bleeding, persistent thirst, decreased urine output, light-headedness, or a sense of impending doom.**
Nonsurgical Management: Drug Therapy What should you assess for while taking vasodilators?
• Assess blood pressure at least every 15 min because the drug can cause systemic vasodilation and hypotension, especially in older adults. • For Sodium nitroprusside, protect drug container from light because light degrades the drug quickly.
Nonsurgical Management: Drug Therapy What should you assess for while taking Inotropic agents?
• Assess for chest pain because these drugs increase myocardial oxygen consumption and can cause angina or infarction. • Assess blood pressure every 15 min because hypertension is a symptom of overdose.
Nonsurgical Management: Drug Therapy What should you assess for while taking sympathomimetic drugs?
• Assess patient for chest pain because these drugs increase myocardial consumption and can cause angina or ischemia. • Monitor urine output hourly because higher doses decrease kidney perfusion and urine output. • Assess blood pressure every 15 min because hypertension is a symptom of overdose. • Assess patient for headache because headache is an early symptom of drug excess. • Assess every 30 min for extravasation; check extremities for color and perfusion because if the drug gets into the tissues, it can cause severe vasoconstriction, tissue ischemia, and tissue necrosis. • Assess for chest pain because the drug can cause rapid onset of vasoconstriction in the myocardium and impair cardiac oxygenation.
What major pathophysiologic effects does shock have on the cardiovascular system?
• Massive vasodilation • Widespread extravasation of fluid into the interstitial compartment • Myocardial depression.
What does the ADH hormone do?
• The antidiuretic hormone causes salt and water retention which increased preload and cardiac output.
What occurs during hypovolemic shock?
₋ A decrease in MAP of 5 to 10 mm Hg below the patient's normal baseline value due to loss of intravascular volume results in decreased venous return to the heart, reduced CO and decreased stimulation of baroreceptors ₋ This information is transmitted to brain centers, which stimulate compensatory mechanisms to help ensure continued blood flow and oxygen delivery to vital organs while limiting blood flow to less vital areas. ₋ If volume is not replaced, compensatory mechanisms eventually become ineffective resulting in tissue hypoxia, cellular death and eventually MODS.
What laboratory assessments should be done during shock?
₋ Although no single test confirms or rules out shock, changes in laboratory data may support the diagnosis. ₋ As shock progresses, arterial blood gas values become abnormal. ₋ The pH decreases, the partial pressure of arterial oxygen (PaO2) decreases, and the partial pressure of arterial carbon dioxide (PaCO2) increases. ₋ ↑ or ↓Hematocrit and hemoglobin levels ₋ ↑ Potassium ₋ ↑ Lactic acid
What questions should you ask during the psychosocial assessment?
₋ Avoid asking questions that can be answered with a "yes" or a "no" response. Consider these points during assessment: • Is it necessary to repeat questions to obtain a response? • Does the response answer the question asked? • Does the patient have difficulty making word choices? • Is the patient irritated or upset by the questions? • Can the patient concentrate on a question long enough to answer, or is the attention span limited? • Talk with the family to determine whether the patient's behavior and cognition are typical or represent a change.
Shock Physical Assessment: What kidney and urinary changes occur with shock?
₋ Kidney and urinary changes occur with shock to compensate for decreased mean arterial pressure (MAP) by saving body water through decreased filtration and increased water reabsorption. o Assess urine for volume, color, specific gravity, and the presence of blood or protein. o Decreased urine output is a sensitive indicator of early shock. o Measure urine output at least every hour. In severe shock, urine output may be absent. o When hypoxia or anoxia persists beyond about an hour, patients are at risk for acute kidney injury (AKI) and kidney failure.
What cardiovascular alterations happen later in shock?
₋ Later, such stress on the heart causes an increase in myocardial metabolism and myocardial oxygen consumption and eventually cause the myocardium to fatigue. ₋ Also, as circulating myocardium depressants (Inflammatory Cytokines) increase, the heart becomes hypodynamic, with low CO
Multiple Organ Dysfunction Syndrome (MODS): What happens when Liver Failure occurs?
₋ Liver failure tends to occur later because the liver has a considerable compensatory capacity. Progressive liver dysfunction results in hepatic failure. - Hepatic failure affects multiple body systems, because the liver has so many functions, including synthesis of albumin, clotting factors, and drug metabolism.
What is hypovolemic shock?
₋ Occurs when inadequate circulating blood volume decreases MAP. ₋ Most commonly, hypovolemic shock is caused by: • sudden blood loss or • severe dehydration
How do you prevent Hypovolemic shock?
₋ Prevention is the best treatment. Avoid trauma and hemorrhage through: • Proper safety equipment • Seat belts • Awareness of hazards in home/workplace ₋ Recognizing hypovolemic shock is a major nursing responsibility. Please keep in mind that just being a patient in the acute care setting is a risk factor. ₋ The nurse should identify patients at risk for dehydration and assess for early signs and symptoms. This is especially important for those who have reduced cognition or mobility or who are on NPO status. ₋ The nurse should assess for early manifestations
Multiple Organ Dysfunction Syndrome (MODS): What happens during renal dysfunction?
₋ Renal dysfunction can occur secondary to poor renal perfusion and prolonged ischemia to renal tubular cells, or intrarenal causes such as nephrotoxic drugs.
Shock Physical Assessment: What Respiratory changes occur with shock?
₋ Respiratory changes with shock are an adaptive response to help maintain GAS EXCHANGE when tissue PERFUSION is decreased.: o Assess the rate and depth of respiration. o Respiratory rate increases during shock to ensure that oxygen intake is increased so it can be delivered to critical tissues. o Oxygen saturation is assessed through pulse oximetry. o Pulse oximetry values between 90% and 95% occur with the nonprogressive stage of shock, and values between 75% and 80% occur with the progressive stage of shock. o Any value below 70% is considered a life-threatening emergency and may signal the refractory stage of shock.
What is cardiogenic shock?
₋ Results from loss of contractile function of the heart. ₋ It is usually diagnosed when more than 40% of ventricular mass is damaged resulting in inadequate CO and tissue perfusion and systemic and pulmonary hemodynamic alterations.
What is SIRs caused by? What is the big problem SIRs leads to?
₋ SIRS may be caused by any type of shock or by other insults such as massive blood transfusion, traumatic injury, brain injury, surgery, burns, and pancreatitis and infection. - If left unrecognized and untreated, can cause MODS. Thus, SIRS criteria should be evaluated in any patient with shock or any condition that might lead to shock.
What are the signs of the refractory stage?
₋ Signs are a rapid loss of consciousness; nonpalpable pulse; cold, dusky extremities; slow, shallow respirations; and unmeasurable oxygen saturation.
Shock Physical Assessment: What skeletal muscle changes occur with shock?
₋ Skeletal muscle changes during shock include weakness and pain in response to tissue hypoxia and anaerobic metabolism, which are later indications. o Weakness is generalized and has no specific pattern. o Deep tendon reflexes are decreased or absent.
Shock Physical Assessment: Why do skin changes occur with shock?
₋ Skin changes occur because of reduced blood flow in the skin. o An early compensatory mechanism is skin blood vessel constriction, which reduces skin PERFUSION. o This allows more blood to perfuse the vital organs, which cannot tolerate low oxygen levels. o Assess the skin for temperature, color, and moisture. o Evaluate Capillary Refill
What occurs during the Initial Stage of shock?
₋ The initial stage is present when the patient's baseline MAP is decreased by less than 10 mm Hg. ₋ Compensatory mechanisms are effective at returning systolic pressure to normal at this stage; thus, oxygen PERFUSION to vital organs is maintained. ₋ Cellular changes include increased anaerobic metabolism in some tissues with production of lactic acid, although overall metabolism is still aerobic. ₋ The compensation responses of vascular constriction and increased heart rate are effective, and both cardiac output and MAP are maintained within the normal range. ₋ Because vital organ function is not disrupted, the indicators of shock are difficult to detect at this stage. **Early identification of the SIRS symptoms, could help the early diagnosis and management of shock**
What can cause cardiogenic shock?
₋ The most common cause of cardiogenic shock is an extensive left ventricular myocardial infarction. ₋ Other causes of cardiogenic shock include papillary muscle rupture, ventricular septal rupture, cardiomyopathy, acute myocarditis, cardiac valve disease, and dysrhythmias. ₋ Acute cardiogenic shock following a myocardial infarction is associated with in-hospital mortality rates of more than 50%.
What occurs during the progressive stage?
₋ The progressive stage of shock occurs when there is a sustained decrease in MAP of more than 20 mm Hg from baseline. ₋ Compensatory mechanisms are functioning but can no longer deliver sufficient oxygen, even to vital organs. ₋ Vital organs develop hypoxia, and less vital organs become anoxic (no oxygen) and ischemic (cell dysfunction or death from lack of oxygen). ₋ As a result of poor PERFUSION and a buildup of metabolites, some tissues die.
Shock: Planning and Implementing What are the purposes of shock management?
₋ The purposes of shock management are to reverse the shock, maintain tissue oxygenation, restoring vascular volume, support compensatory mechanisms, and preventing complications. ₋ Monitoring is critical to determine whether the patient is responding to therapy or whether shock is progressing and a change in intervention is needed.
What occurs during the Refractory Stage?
₋ The refractory stage of shock occurs when too much cell death and tissue damage result from too little oxygen reaching the tissues. ₋ Vital organs have extensive damage and cannot respond effectively to interventions, and shock continues.
What happens if you do not treat shock?
₋ Without treatment, inadequate blood flow to the tissues results in poor delivery of oxygen and nutrients to the cells, cellular starvation, cell death, organ dysfunction progressing to organ failure, and eventual death. ₋ During shock, the body struggles to survive, utilizing a variety of homeostatic, compensatory mechanisms to restore tissue perfusion
Metabolic Alterations caused by Shock: What happens when there is insulin resistance?
₋ cells are progressively unable to use glucose, protein, and fat as energy sources. ₋ Hyperglycemia that is resistant to insulin therapy is a frequent finding in early shock.
What are normal Lactate levels and what indicates shock?
↑ Lactic acid (lactate) (arterial) (3-7 mg/dL, 0.3-0.8 mmol/L) ₋ Increases due to anaerobic metabolism with buildup of metabolites
What are normal potassium levels and what indicates shock?
↑ Potassium (3.5-5.0 mEq/L) - Increases due to dehydration and acidosis
What are normal hematocrit and hemoglobin levels and what indicates shock?
↑ or ↓ Hematocrit (F : 37%-47%, M: 42%-52%) ↑ or ↓ Hemoglobin (F: 12-16 g/dL, M: 14-18 g/dL) • Decrease if shock is caused by hemorrhage from poor CLOTTING. • When shock is caused by dehydration or a fluid shift, hematocrit and hemoglobin levels are elevated.
What are normal pH, PaO2, and PaCO2 levels and what indicates shock?
↓ pH (arterial) (7.35-7.45) - Decreases during shock ↓ PaO2 (80-100 mm Hg) - Decreases during shock ↑ PaCO2 (35-45 mm Hg) - Increases during shock
Shock Physical Assessment: What cardiovascular changes occur with shock?
₋ Cardiovascular changes that occur with hypovolemic shock start with decreased mean arterial pressure (MAP) leading to compensatory responses: o Increased heart rate is the first sign of shock. o Assess the central and peripheral pulses for rate and quality. o In the initial stage of shock, the pulse rate increases above the patient's baseline to keep cardiac output and MAP at normal levels, even though the actual stroke volume (amount of blood pumped out from the heart) per beat is decreased. o Because stroke volume is decreased, the peripheral pulses are difficult to palpate and easily blocked: ••• As shock progresses, peripheral pulses may not be palpable, and a Doppler may be needed. o With vasoconstriction, diastolic pressure increases, but systolic pressure remains the same. - As a result, the difference between the systolic and diastolic pressures (pulse pressure) is smaller or "narrow.": ••• Systolic pressure decreases as shock progresses and cardiac output decreases. •••A reduced systolic pressure narrows the pulse pressure even further. ••• When shock continues and interventions are not adequate, compensation fails, both systolic and diastolic pressures decrease, and blood pressure is difficult to hear. Palpation or a Doppler device may be needed to detect the systolic blood pressure. o Monitor blood pressure for changes from baseline levels and for changes from the previous measurement. o For accuracy, use the same equipment on the same extremity. o Validate an abnormal electronic BP reading with a manual BP reading.
Shock Physical Assessment: What central nervous system (CNS) changes occur with shock?
₋ Central nervous system (CNS) changes with shock first manifest as thirst. o Thirst is caused by stimulation of the thirst centers in the brain in response to decreased blood volume. o Assess the patient's level of consciousness (LOC) and orientation, which are sensitive to cerebral hypoxia. o In the initial and nonprogressive stages, patients may be restless or agitated and may be anxious or have a feeling of impending doom. o As hypoxia progresses, confusion and lethargy occur, which progress to loss of consciousness as cerebral hypoxia worsens.
What compensatory mechanism happens when arterial pressure decreases during shock?
₋ Decreased arterial pressure would also result in stimulating the posterior pituitary gland to secrete ADH. (THEN ADH CAUSES WHAT?
What compensatory mechanism happens when blood pressure decreases during shock?
₋ Decreased blood pressure would result in decreased baroreceptors stimulation (pressure sensitive nerve receptors at the aortic arch and carotid sinus), which will stimulate sympathetic nerves and adrenal medulla. • This would result in the release of norepinephrine into sympathetic synapses and into blood stream. • Which in turn would result in systemic arteriolar and venous vasoconstriction, increased myocardial contractility and increased heart rate. • The end result is increased cardiac output and blood pressure.
What does compensatory mechanisms of shock mean?
₋ During shock, the body struggles to survive, utilizing a variety of homeostatic, compensatory mechanisms to restore tissue perfusion and O2 delivery to cells
Why should you teach family members about post surgical shock?
₋ Hypovolemic shock is a complication of another condition and is resolved before patients are discharged from the acute care setting. ₋ Because surgery and many other invasive procedures now occur on an ambulatory care basis, more patients at home are at increased risk for hypovolemic shock. ₋ Teach patients and family members the early indicators of shock (increased thirst, decreased urine output, light-headedness, sense of apprehension) and to seek immediate medical attention if they appear.
What are the types of shock?
₋ Hypovolemic shock, cardiogenic shock, obstructive shock, and distributive shock. ₋ Types of shock vary because shock is a problem caused by a pathologic condition rather than a disease state. ₋ More than one type of shock can be present at the same time. For example, trauma caused by a car crash may trigger hemorrhage (leading to hypovolemic shock) and a myocardial infarction (leading to cardiogenic shock).
Nonsurgical Management: How is IV therapy used?
₋ IV therapy for fluid resuscitation is a primary intervention for hypovolemic shock. - Types of IV Therapy: ••• Crystalloids and colloids ••• Protein-containing colloid fluids ••• Blood products - PRBCs - Plasma
What is the systemic inflammatory response syndrome (Sirs)? (with shock)
₋ In addition to the activation of the compensatory mechanisms, the progression of shock states involves systemic activation of the inflammatory response. ₋ The term systemic inflammatory response syndrome (SIRS) is used to describe patients in whom the inflammatory response is fully and systemically activated throughout the body.
What are indications of the progressive change?
₋ Indications of the progressive stage include a worsening of changes resulting from decreased tissue PERFUSION. • The patient may express a sense of "something bad" (impending doom) about to happen. • He or she may be confused, and thirst increases. • Objective changes are a rapid, weak pulse; low blood pressure; pallor to cyanosis of oral mucosa and nail beds; cool and moist skin; anuria; and a 5% to 20% decrease in oxygen saturation. • Laboratory data may show a low blood pH, along with rising lactic acid and potassium levels.
Distributive Shock: What is Sepsis (chemical induced) blood vessel tone loss?
₋ Is a widespread infection that triggers Systemic Inflammatory Response resulting in massive vasodilation
What is obstructive shock? What is the most common cause?
₋ Is caused by problems that impair the ability of the normal heart to pump effectively. ₋ The heart itself remains normal, but conditions outside the heart prevent either adequate filling of the heart or adequate contraction of the healthy heart muscle. - The most common cause of obstructive shock is cardiac tamponade.
What is Multiple Organ Dysfunction Syndrome (MODS)?
₋ Is defined as a progressive physiologic failure of several organ systems in acutely ill patients. ₋ The inability to maintain end-organ perfusion and oxygenation because of SIRS or any type of shock may result in MODS.
