2Learning Objectives List the types of shock. Describe the pathophysiology of each type of shock.List the signs and symptoms of each stage of shock.Explain the first aid emergency treatment of shock outside the medical facility.Identify general medical and nursing interventions for shock.Explain the rationale for the medical/surgical treatment of shock.Assist in developing care plans for patients in each type of shock.
3Definition of ShockInadequate tissue perfusion resulting in impaired cellular metabolismDeprives cells of essential oxygen and nutrients, forcing cells to rely on anaerobic (without oxygen) metabolismLess energy is produced and lactic acid, a by-product of anaerobic metabolism, causes tissue acidosis and subsequent organ dysfunctionShock begins when the cardiovascular system fails to function adequately because of an alteration in at least one of four vital components.What are the four vital components?
4Hypovolemic ShockInadequate blood volume to maintain the supply of oxygen and nutrients to body tissuesIntravascular or circulating volume deficits can occur from external or internal lossesBlood volume falls with excessive blood or fluid loss, inadequate fluid intake, or a shift of plasma from the blood vessels into body tissues/organsCauses of blood/fluid loss: hemorrhage, severe diarrhea or vomiting, excessive perspirationExcessive shift of plasma with pathologic states (burns, peritonitis, and intestinal obstruction)
5Cardiogenic Shock Occurs when heart fails as a pump Decreased myocardial contractility causes decreased cardiac output and impaired tissue perfusionDifficult to treat and usually results when diseased coronary arteries cannot meet the demand of the working myocardial cellsCauses include conditions that result in ineffective myocardial cell function, such as dysrhythmias, cardiomyopathy, myocarditis, valvular disease, and structural disorders
6Obstructive ShockPhysical impairment of adequate circulating blood flowObstruction of the heart or great vessels either blocks venous return to the right side of the heart or prevents effective pumping actionCauses: tension pneumothorax, pericardial tamponade, pulmonary embolus, abdominal distention, and aortic dissection
7Distributive ShockThe problem is not loss of blood, but excessive dilation of blood vessels or decreased vascular resistance causing the blood to be improperly distributedFluid pools in dependent areas of body and is not returned to the arterial circulation to supply critical cellular metabolic needsComplicated by increased capillary permeability; plasma leaks into interstitial compartment, decreasing intravascular blood volume
8Distributive Shock Anaphylactic shock A severe allergic reaction that results in the release of chemicals that dilate blood vessels and increase capillary permeabilityFluid leaks out of capillaries into the tissuesPooling of blood in peripheral tissues and the shift of fluid out of the capillaries cause venous return and cardiac output to fallAllergic reaction also causes constriction of the bronchi and airway obstructionWhat are some substances that people can be allergic to?The onset of anaphylaxis is typically sudden and dramatic following exposure to a substance to which the patient has developed antibodies.
9Distributive Shock Septic shock Hypotension unresponsive to fluid resuscitation along with metabolic acidosis, acute encephalopathy, oliguria, and/or coagulation disordersPathogenic organisms (bacteria, fungi, viruses, rickettsiae) release toxic substances that cause blood vessels to dilate and decrease vascular resistance and increase capillary permeabilityIncreased permeability: leakage of plasma proteins and reduced intravascular volume, preload, and cardiac output that contributes to inadequate tissue perfusion and oxygenationSepsis is a systemic inflammatory response to a documented or suspected infection; sepsis can progress to septic shock.
10Distributive Shock Neurogenic shock Disruption in the nervous system affects the vasomotor center in the medullaDisrupted sympathetic nerve impulses result in vasodilation or loss of vascular resistanceSigns and symptoms: pooling of blood in peripheral tissues with subsequent decreased venous return and cardiac output; bradycardia with hypotensionCauses: injury or disease of the upper spinal cord, spinal anesthesia, depression of the vasomotor center from certain drugsIn neurogenic shock, what is the result of disturbances that disrupt sympathetic nerve impulses?
11Effects of Shock on Body Systems and Functions Respiratory systemTissue hypoxia and anoxia, respiratory failure, acute respiratory distress syndrome (ARDS)Acid-base balanceMetabolic acidosisCardiovascular systemMyocardial depression, disseminated intravascular coagulation (widespread clotting caused by sluggish flow of acidic blood combined with bacterial endotoxins or clotting factors released by destruction of red blood cells)
12Effects of Shock on Body Systems and Functions Neuroendocrine systemRelease of catecholamines (epinephrine and norepinephrine), mineralocorticoids (aldosterone and desoxycorticosterone), glucocorticoids (hydrocortisone), and antidiuretic hormone; decreased level of consciousness when cerebral blood flow fallsImmune systemDepressed immune response
13Effects of Shock on Body Systems and Functions Gastrointestinal systemDecreased peristalsis, ischemia of intestinal submucosa, impaired liver functionRenal systemReduced glomerular filtration, inadequate renal perfusion, tubular necrosis, renal ischemia
15Early, Reversible, and Compensatory Stages Continued reduction in cardiac output triggers set of neural, endocrine, and chemical compensatory mechanisms in an effort to overcome the consequences of anaerobic metabolism and maintain blood flow to vital organsDuring this stage the following may occur:Activation of baroreceptors in the carotid arteries and the aorta stimulate the sympathetic nervous systemSympathetic stimulation: increased heart rate, constriction of peripheral blood vessels, and reduced blood flow to the kidneys, lungs, muscles, skin, and gastrointestinal (GI) tract
16Early, Reversible, and Compensatory Stages EventsDecreased renal blood flow triggers the release of renin and a sequence of events that produces angiotensin IIAdrenal cortex secretes aldosterone, which promotes sodium retention by the kidneysAntidiuretic hormone released by posterior pituitary, resulting in additional retention of water by the kidneysFalling blood pH and increasing arterial carbon dioxide detected by chemoreceptors in the carotid arteries, which stimulate the respiratory centerIncreased respiratory rate and depth help to eliminate excess carbon dioxide and normalize the blood pH
17Early, Reversible, and Compensatory Stages SymptomsMental statusIrritability, restlessnessBlood pressureNormal or slightly decreased, decreasing pulse pressure, orthostatic hypotensionPulseIncreased rate; may be thready (as a result of vasoconstriction) or bounding (caused by vasodilation) decreased rate (bradycardia) may be present in neurogenic shock due to loss of sympathetic stimulationRespirationsIncreased rate and depth
18Early, Reversible, and Compensatory Stages Urine outputDecreasedSkinCool and paleException: warm and dry with septic shockAbdomenDecreased bowel soundsBlood glucoseIncreasedOtherThirst
19Intermediate (Progressive) Stage Cause of shock is not corrected or if compensatory mechanisms continue without reversing the shockNeural, endocrine, chemical compensatory mechanisms begin to function independently and in oppositionSystemic circulation continues to vasoconstrict in the attempt to maintain blood flow to vital organsDecrease in peripheral blood flow leads to weak or absent pulses and ischemia of the extremitiesBlood becomes more viscous or thick, causing clumping of red blood cells, platelets, and proteinsDeprived of oxygen, cells resort to anaerobic metabolism and produce lactic acid, resulting in metabolic acidosisDepressant effect on myocardial cells
20Intermediate (Progressive) Stage SymptomsMental statusListlessness, confusionBlood pressureDecreased; narrow pulse pressurePulseWeak and thready, tachycardia, dysrhythmiasRespirationsIncreased, deep, crackles present on auscultation
21Intermediate (Progressive) Stage TemperatureSubnormal, except with septic shockUrine outputDecreased; possible renal failureSkinCold, pale, clammy, slow capillary refill, cyanosisOtherDry mouth, thirst, sluggish pupillary response, peripheral edema, and muscle weaknessWhat is MODS?
22Irreversible (Refractory) Stage Irreversible changes in vital organs as compensatory mechanisms failTissue perfusion deteriorates, as blood remains pooled in the capillary bed where sluggish flow is further compromised by clumping and the formation of clotsCoronary artery perfusion is reduced causing ischemia and dysrhythmiasCerebral ischemia occurs as a result of the decrease in cerebral blood flowDeath is imminentEven patients who are resuscitated during this stage often die within a week or two
24Diagnosis Based on history and physical examination Tests and procedures that help establish type of shock, stage, and the causeBlood and urine studies, measurement of hemodynamic pressures, chest radiograph, ECG and continuous cardiac monitoring, pulse oximetry and arterial blood gases, and urine output
25First Aid for Shock Outside the Medical Facility Treatment provided before medical care is available can have a significant effect on the chances of survivalHealthy People 2010 objectives (2000): the necessity for increasing public awareness of how and whom to call for emergency assistance in addition to providing education concerning initial lifesaving procedures to be followed until arrival of emergency respondersWhat first aid interventions should be performed for the patient in shock?
26OxygenationBrain cells begin to die after 4 minutes without oxygen, and oxygen consumption increases as delivery decreases in shock: poor prognosisOxygen delivery such as increasing arterial oxygen saturation, hemoglobin, and cardiac outputSupplemental oxygen may be used or mechanical ventilation may be necessaryParalytics, sedatives, and analgesics may be ordered to decrease oxygen requirements
27Fluid Replacement Normal saline is usually administered initially Subsequent fluids may include various crystalloids and colloids depending on situationCrystalloids provide replacement water and electrolytes for all fluid compartmentsColloids remain in the vascular system and draw fluid into the bloodstreamEspecially important when large amounts of plasma proteins have been lostExcept for cardiogenic shock, all types of shock require significant fluid volume replacement.The hemorrhaging patient will require blood to replace deficient hemoglobin.The patient’s response must be closely monitored during fluid replacement to ensure adequate, but not excessive, replacement.How is adequate fluid replacement best determined?
28Pharmacologic Therapy Based on manipulation of the cardiac dynamics: contractility, preload, afterload, and heart rateNo one drug will provide nutrients and oxygen to the cells; several agents assist in manipulation of the four circulatory componentsSee the Drug Therapy table on pp
29Mechanical Management Management of shock may include the use of mechanical devices that assist in the restoration of cellular perfusionWhat mechanical devices may be used to manage shock?
33AssessmentContinuous monitoring of cardiac rate and rhythm; blood pressure; body temperature; hemodynamic values; respiratory rate, rhythm, and depth; and arterial blood gasesObserve skin color; palpate for warmth and moistureNote pupil size, equality, and response to lightDescribe patient’s level of consciousness and response to commands, and assess reflexesAuscultate heart, lung, and bowel sounds
34AssessmentObserve movement of the chest wall with respirations; inspect and palpate abdomen for distentionPalpate for bladder distention, and note the appearance of urine and the hourly outputInspect the extremities for color, and palpate for peripheral pulses and edemaInspect IV infusion sites for pallor, swelling, or coolness that suggests extravasation
36Nursing DiagnosisThe primary nursing diagnosis for all patients in shock is Altered Tissue PerfusionMay be related to alteration(s) in circulating blood volume, myocardial contractility, blood flow, or vascular resistance
37Ineffective Tissue Perfusion Assessment must include all body systemsIf not corrected, shock eventually results in failure of all major organs
38Decreased Cardiac Output Administer intravenous fluids as orderedAssess for fluid volume deficit and excessAdminister inotropic and antidysrhythmic agents as ordered; continuous cardiac monitoringMaintain adequate body heatFever may be treated with acetaminophen or nonsteroidal anti-inflammatory drugsContinuous cardiac monitoring enables you to assess the effectiveness of the drugs.How can you reduce oxygen requirements?
39Disturbed Thought Processes and Anxiety May be anxious, then confused and disoriented, and finally unconsciousRemain calm; give simple explanations of what is being doneProtect patient from constant, excessive noise and lightRepeat orientation, instructions, and reassurance oftenIn the presence of unconscious patients, remember that they may hear even when they cannot respondContinue to speak to the patient and beware of negative comments
40Deficient Fluid Volume Monitor for hypovolemiaTachycardia, hypotension, tachypnea, decreased urine output, and decreased central venous pressure and pulmonary artery pressureAdminister intravenous fluids cautiously while assessing output of urineAssess for fluid overloadFull, bounding pulse; dilute urine, increased respiratory rate; abnormal lung sounds; dyspnea; and edemaWhen should the physician be notified about a decreasing urine output?
41Risk for Injury Related to changes in consciousness Related to therapeutic measuresAntidysrhythmics can depress cardiac activityAnticoagulants can permit excessive bleedingExtravasation of vasopressors (drugs that raise blood pressure by vasoconstriction) can cause local tissue necrosisHigh risk for complications of immobilityPersonal hygiene may be limited by the patient’s tolerance of such activityClosely monitor the patient for both therapeutic and adverse effects of drugs used to treat the patient in shock.What measures should be instituted to prevent pressure ulcers?
42Risk for InfectionIV lines, indwelling urinary catheters, chest tubes, airways, ventricular assist devices, and other equipment provide avenues for infection in patient in shockWash your hands thoroughly between patientsFollow agency guidelines for care of IV and urinary cathetersUse aseptic technique when inserting these devices, caring for insertion sites, and providing wound careMonitor for signs of infectionWhen antibiotics are ordered, administer them on schedule to maintain a therapeutic blood levelWhich patients have the greatest risk for infection?What are the signs of infection?
43Ineffective Family Coping Be sensitive to the needs of the family for information and supportExplain the nursing care and encourage them to ask questionsOffer the services of a counselor or patient representative
44Systemic Inflammatory Response Syndrome (SIRS) Generalized inflammation that threatens vital organsConditions that can lead to SIRS are shock, multiple transfusions, massive tissue injury, burns, and pancreatitisEffects are damage to the endothelium of blood vessels and a hypermetabolic stateIncreases capillary permeability; allows fluid to leak into body tissuesHypotension, microemboli, and shunting of blood flow compromise organ perfusionThe hypermetabolic state is characterized by increased serum glucose, which eventually depletes carbohydrate, fat, and protein stores
45DiagnosisDiagnosis of SIRS is made when a patient manifests two or more of the following:Temperature less than 97° F (36° C) or more than 100.4° F (38° C)Heart rate more than 90 bpmRespiratory rate more than 20/min, or Paco2 less than 32 mm HgWBC count less than 4000 cells/mm3 or more than 12,000 cells/mm3, or more than 10% immature (band) neutrophils
46SIRS Manifestations Range from mild to severe Sepsis A patient has SIRS with a confirmed infectionAdvanced SIRS and failure of more than one organDeterioration of cardiac, pulmonary, renal, and central nervous systems, liver, pancreas, and GI tractThrombocytopenia may develop and progress to disseminated intravascular coagulationIf three or more organs fail, the prognosis is very poorMultiple organ dysfunction syndrome (MODS)More than one organ begins to fail
47Medical Treatment and Nursing Interventions Prevent and treat infectionMonitor potential sites; assess for signs and symptomsMaintain strict asepsis with invasive procedures and equipmentExercise scrupulous hand washingAdminister antimicrobials as orderedAdminister enteral feedings as ordered to enhance perfusion of the GI tract
48Medical Treatment and Nursing Interventions Maintain tissue oxygenationAdminister sedatives and analgesics as ordered to reduce oxygen requirementsMonitor the patient on mechanical ventilationAdminister drugs to improve cardiac output and tissue perfusion as orderedPlan care to minimize physical demands on patientProvide nutritional and metabolic supportProvide enteral or parenteral nutrition as orderedMonitor blood glucose and weight
49Medical Treatment and Nursing Interventions Support failing organsMechanical ventilation for respiratory distress syndromeReplacement therapy for renal failure