Med-Surg (Kinsella)-Chapter 9 (Nursing Care or Patients in Shock)

What are causes of extracardiac obstructive shock?

*All lead to decrease cardiac output* -pericardial tamponade -tension pneumothorax -acute pulmonary hypertension -tumors -pulmonary embolisms

What are some causes of hypovolemic shock

*Caused by severe loss of body fluid* -dehydration -hemorrhage (internal/external) -fluid loss from burns -vomiting -diarrhea -loss of intravascular fluid from sepsis or trauma -heat exhaustion -stroke

Why would prolonged shock cause extensive damage to the organs and organ systems?

*Caused from issue ischemia and injury* -Lungs: acute respiratory failure and distress syndrome -Renal system: renal failure -Heart: dysrhythmias, myocardial ischemia and depression -Liver: abnormal clotting, decreased production of plasma proteins, elevated serum levels -Immune system: depletion of defense components -GI system: mucosal injury, paralytic ileus, pancreatitis, absorption of endotoxins and bacteria -CNS: ischemic damage, necrosis, brain death

List the intervention priorities/therapeutic measures for shock in order.

*Look at Table 9.5 (p. 139) for therapeutic measures of these priorities* 1. Airway 2. Breathing and respiratory support 3. Cardiovascular support 4. Maintenance of circulatory volume 5. Control bleeding if present 6. Assessment of neurologic status 7. Treatment of life-threatening injuries 8. Determination and treatment of the cause of shock

How does neurogenic shock occur?

Occurs when *dysfunction or injury to the nervous system* causes *extensive dilation of peripheral blood vessels*

What are S/S of extracardiac obstructive shock?

S/S similar to hypovolemic shock, except *jugular veins usually distended*

What is the most common type of distributive shock?

Septic shock, which results from severe sepsis

What is the most severe type of distributive shock?

anaphylactic shock

Define anaphylactic shock.

extreme hypersensitivity to an antigen

How is septic shock characterized (distinguished, identified)?

low BP pressure despite fluid therapy

Supplying an organ or tissue with blood is known as what?

perfusion

What are the classifications of shock?

-*Hypovolemic:* decrease in circulating blood volume -*Cardiogenic:* cardiac failure as a pump -*Extracardiac obstructive:* blockage of blood flow outside the heart -*Distributive:* excessive dilation of venules and arterioles; occurs when peripheral vascular resistance lost due to massive vasodilation

What is usually the first sign of shock? What is the hallmark characteristic seen in ALL forms of shock?

-First sign: tachycardia -Sign seen in ALL forms of shock: decrease in BP

What are S/S of neurogenic shock?

-hypotension -altered mental status *During early stages:* -bradycardia -warm, dry skin *Later stages:* -tachycardia -cool, clammy skin

What are the most common causes of anaphylactic shock?

-insect stings -antibiotics: esp. penicillin -food allergies: shellfish, peanuts -anesthetics -contrast dye -blood products

What are clinical S/S of hypovolemic shock?

-restlessness -pale, clammy skin -tachypnea -tachycardia -flat, nondistended peripheral veins -decreased jugular vein circumference -decreased urine output -altered mental status -hypotension

Tissue perfusion and BP are maintained the the body by what three mechanisms?

1. Adequate blood volume 2. An effective cardiac pump 3. Effective blood vessels

Define pericardial tamponade.

Compression of the heart by an abnormal filling of the pericardial sac with blood

What is the main difference between hypovolemic and distributive shock?

Unlike hypovolemic shock in which there is an ACUTAL loss of blood volume, distributive shock occurs when the body's *fluid distribution is abnormally altered* within the body.

How should assessment be carried out for patients in shock?

*Must be carried out quickly and can follow a head-to-toe approach* -A: Airway checked for patency and opened as necessary -B: Breathing checked for rate, depth, and symmetry of chest movement; check accessory muscle use and adventitious lung sounds -C: checked with BP; peripheral pulses palpated; pulse assessed for quality; palaption of abd can reveal internal bleeding; *cap. refill check unreliable in shock pts* -D: Disability determined by pt's LOC; check CSM (circulation, sensation, and mobility) in all four limbs

What differentiates cardiogenic shock from other forms of shock?

*Pulmonary edema* -Fluid therapy can CONTRIBUTE further to pulmonary edema, which can be life threatening

What are S/S of anaphylactic shock?

*S/S similar to hypovolemic shock except:* -urticaria: hives -pruritis: itchy skin -wheezing -laryngeal edema: swelling of larynx -angioedema: edema of skin, mucous membranes, or internal organs -severe bronchospasm *If conscious, pts can:* -be extremely apprehensive (ie. anxious, restless) -be SOB -report metallic taste

When is SIRS diagnosed?

*When two or more of the following signs are present:* -abnormal body temp. (high or low temp.) -heart rate grater than 90 BPM -resp. rate greater than 20 per min. -WBC less than 4000/mm3 or greater than 12,000/mm3, or 10% bands (immature neutrophils) *Left untreated, septic shock progresses to second phase c S/S similar to hypovolemic shock*

Define shock.

*inadequate tissue perfusion* in which there is insufficient delivery of O2 and nutrients to the body's tissues and inadequate removal of waste products; an imbalance between O2 supply and demand

Explain S/S of hypovolemic shock when there are different percentages of blood loss.

-*15% (750 mL):* body usually able to compensate; initial symptom may only be tachycardia, BP may initially rise then fall below 80 mm Hg -*20%-25%:* tachycardia, mild to moderate hypotension -*40% or greater (2000 mL):* all clinical S/S of shock

What are some complications of shock?

-*Acute respiratory distress syndrome (ARDS):* respiratory failure (supply pt c O2 and mechanical ventilation) -*Disseminated intravascular coagulation (DIC):* results from ischemic damage to lining of blood vessels and multiple tiny thrombi form -*Multiple organ dysfunction syndrome (MODS):* major cause of death following shock; usually failure of kidneys, heart, liver, and finally cerebral and GI function

Explain shock.

-*life-threatening* medical emergency -pt in a state of *circulatory collapse* -Results in *organ damage and death* without immediate treatment

What is SIRS?

-AKA systemic inflammatory response syndrome -Definition: systemic inflammation, which is the body's response to serious illness. (Thus, sepsis is SIRS from an infection.)

What occurs in the body when BP falls?

-Body responds by activating the *sympathetic nervous system* -*Epinephrine and norepinephrine* released from adrenal medulla and *increased cardiac output* (causes heart to beat faster and stronger) -Blood shunted away from skin, kidneys, and intestines (preserves blood flow to brain, liver, and heart) -Epinephrine, cortisol, and glucagon raise BS levels -Stimulation of renin-angiotensin-aldosterone system (causes vasoconstriction and retention of Na+ and H2O to further decrease further fluid loss) -Respiratory rate increases *These compensatory responses produce classic S/S of initial stage of shock*

What occurs when there is inadequate tissue blood flow?

-Causes a change to anaerobic metabolism due to lack of O2 -Results in production of *lactic acid* as an unwanted byproduct

What are causes of cardiogenic shock?

-Main cause: acute myocardial infarction (AMI) and myocardial ischemia -traumatic injury to the heart -myocarditis -cardiomyopathy -heart valve defects -endocarditis -severe dysrhythmias -end-stage heart disease

What are causes of sepsis?

-Most often cause: Gram-positive bacteria -Other bacteria, fungi, viruses, or parasites

When listening and palpating to the pulse of a pt in shock, how may it be charactereized?

-Peripheral pulse: bradycardic or absent in later stages -Apical pulse: commonly weak and thready

How are epinephrine autoinjectors used? Is it given IM, IV, ID, or SubQ?

-Prescription requested -Given subcutaneously -Teach pt to carry at all times -Medical treatment must be sought STAT p use *Asthma or delay of epi injections can increase risk of death*

What are S/S of cardiogenic shock?

-S/S similar to hypovolemic shock -May also have distended jugular and peripheral veins -Symptoms of HF ie pulmonary edema

What are the types of distributive shock?

-Septic shock -Neurogenic shock -Anaphylactic shock

How are therapeutic measures for shock carried out?

-The *exact nature* of the *shock must be determined WHILE life-threatening S/S are treated.* This must be done quickly. -Interventions are prioritiezed

What are some adventitious lung sounds that can be accompanied with shock?

-Wheezing: anaphylactic shock -Crackles: cardiogenic shock or if pt received too much fluid IV

What occurs if the one of the body's mechanisms for maintenance of tissue perfusion and BP fail?

-When one fails, body compensates by making change in one or both of the other two mechanisms not affected. -Shock occurs when compensatory mechanisms fail, resulting in inadequate tissue perfusion.

Besides spinal cord injury, what are other causes of neurogenic shock?

-general anesthesia -fever -metabolic disturbances -brain contusions -concussions

What conditions increase risk of septic shock?

-older age -chronic illness -trauma -diabetes -immunocompromised pts: chemo, corticosteroid therapy, HIV -burns -malnutrition -invasive catheters, procedures, and devices -antimicrobial resistant organisms

What are the classic S/S of initial stage of shock?

-tachycardia: *pts on meds that block the sympathetic NS response will not exhibit tachycardia* -tachypnea -restlessness -anxiety -cool, clammy skin with pallor -oliguria -acidosis *S/S included from Table 9.7 (p. 141):* -hypotension -cyanosis -altered mental status

Internal bleeding may be indicated in palpation of the abdomen. How may the abdomen feel?

-tender -distended -a "boardlike" abdomen

What are common causes of shock?

1. Inadequate cardiac output (caused by HF) 2. Sudden loss of blood volume (resulting from hemorrhage) 3. Sudden decrease in peripheral vascular resistance (caused by anaphylaxis, sepsis, or neurologic alterations); Arteries are excessively dilated causing peripheral vascular resistance to decrease *Help for #3: As the arteries constrict, the resistance increases and as they dilate, resistance decreases. This also causes low BP. Vascular resistance is the resistance that must be overcome to push blood through the circulatory system and create flow*

Define acidosis.

A decrease in blood pH *below 7.35* which is one of the classic signs of shock

Define cardiac output.

A measure of the pumping ability of the heart; amount of blood pumped by the heart per min.

Define anaphylaxis.

A sudden severe allergic reaction to an allergen.

Define tension pneumothorax.

Abnormal accumulation of air with buildup of pressure in the pleural space

What is the most common cause of neurogenic shock?

Although a *rarer form of shock*, most commonly from *spinal cord injury* (referred to as spinal shock) -Factors stimulate parasympathetic nervous system or block sympathetic nervous system

Define acute pulmonary hypertension.

An excessive buildup of pressure in the pulmonary arteries caused by sudden obstruction of the pulmonary artery

Define sepsis.

An infection that has spread to the bloodstream; a serious bloodstream infection resulting from systemic infection and inflammation

Why is anaerobic metabolism necessary and helpful if it produces the complication of metabolic acidosis?

Because cells are deprived of O2, anaerobic metabolism can supply the energy and nutritional needs of the cell for only a few minutes to prevent cell death. (Similar suggested answer can be found on p. 144 in textbook under "Anaerobic Metabolism.")

Define ischemia.

Condition of inadequate blood supply

What occurs in the body when a pt is experiencing septic shock?

Extensive release of chemical mediators and endotoxins causes dilation of blood vessels and loss of fluid into the interstitial space

Define myocarditis.

Inflammation of the heart muscle

Which organs are commonly injured first after tissue ischemia and injury caused by prolonged shock? How can this be prevented?

Kidneys -Can tolerate reduced blood flow for about *1 hr* -Can be prevented and treated by *replacing lost fluids*