Shock

Shock is a life-threatening condition with a variety of underlying causes. It is characterized by inadequate tissue perfusion that, if untreated, results in cell death. The nurse caring for the patient with shock or at risk for shock must understand the underlying mechanisms of shock and recognize its subtle as well as more obvious signs. Rapid assessment and response are essential to the patient’s recovery.

1. Dr.Vinoli.S.G,M.Sc (N), Ph.D (N),PGDHM Professor, Universal College of Nursing SHOCK

2. INTRODUCTION Shock is a life-threatening condition with a variety of underlying causes . It is characterized by inadequate tissue perfusion that, if untreated, results in cell death. The nurse caring for the patient with shock or at risk for shock must understand the underlying mechanisms of shock and recognize its subtle as well as more obvious signs . Rapid assessment and response are essential to the patient’s recovery . 11/29/2019 2 Vinoli.S.G

3. DEFINITION Shock can be defined as a condition in which systemic blood pressure is inadequate to deliver oxygen and nutrients to support vital organs and cellular function (Mikhail, 1999). 11/29/2019 3 Vinoli.S.G

4. Shock is a syndrome characterized by decreased tissue perfusion and impaired cellular metabolism. This results in an imbalance between the supply of and demand for oxygen and nutrients. 11/29/2019 4 Vinoli.S.G

5. Classification of shock 11/29/2019 5 Vinoli.S.G

6. PRECIPITATING FACTORS 11/29/2019 6 Vinoli.S.G

7. CARDIOGENIC SHOCK Systolic dysfunction myocardial infarction cardiomyopathy Diastolic dysfunction pericardial tamponade Dysrhythmias Bradydysrhythmias Tachydysrhythmias Structural factors valvular abnormality (e.g., stenosis or regurgitation) ventricular septal rupture tension pneumothorax 11/29/2019 7 Vinoli.S.G

8. HYPOVOLEMIC SHOCK Absolute Hypovolemia External loss of whole blood (e.g., hemorrhage from trauma, surgery, GI bleeding) Loss of other body fluids (e.g., vomiting, diarrhea, excessive diuresis , diabetes insipidus , diabetes mellitus) 11/29/2019 8 Vinoli.S.G

9. Relative Hypovolemia Pooling of blood or fluids (e.g., bowel obstruction) Fluid shifts (e.g., burn injuries, ascites ) Internal bleeding (e.g., fracture of long bones, ruptured spleen, hemothorax , severe pancreatitis) Massive vasodilation (e.g., sepsis) 11/29/2019 9 Vinoli.S.G

10. NEUROGENIC SHOCK Disease to the spinal cord Spinal anesthesia Vasomotor center depression (e.g., severe pain, drugs, hypoglycemia, injury) 11/29/2019 10 Vinoli.S.G

11. ANAPHYLACTIC SHOCK Contrast media Blood/blood products Drugs Insect bites Anesthetic agents Food/food additives Vaccines Environmental agents 11/29/2019 11 Vinoli.S.G

12. SEPTIC SHOCK Infection (e.g., urinary tract, respiratory tract, invasive procedure, indwelling lines and catheters) At-risk patients: older adults, patients with chronic diseases (e.g., diabetes mellitus, chronic kidney disease, heart failure), patients receiving immunosuppressive therapy, who are malnourished or debilitated. Gram-negative bacteria most common; also gram-positive bacteria, viruses, fungi, and parasites Gastrointestinal. 11/29/2019 12 Vinoli.S.G

13. CARDIOGENIC SHOCK Cardiogenic shock occurs when either systolic or diastolic dysfunction of the pumping action of the heart results in compromised cardiac output (CO). The heart's inability to pump the blood forward is classified as systolic dysfunction . Diastolic dysfunction is an impaired ability of the right or left ventricle to fill during diastole. 11/29/2019 13 Vinoli.S.G

14. PATHOPHYSIOLOGY 11/29/2019 14 Vinoli.S.G

15. CLINICAL MANIFESTATION Cardiovascular ↓ Capillary refill time ↑ MVO 2 Chest pain may or may not be present Pulmonary Tachypnea Cyanosis Crackles Rhonchi 11/29/2019 15 Vinoli.S.G

16. Renal ↑ Na + and H 2 O retention ↓ Renal blood flow ↓ Urine output Skin Pallor Cool, clammy 11/29/2019 16 Vinoli.S.G

17. Neurologic ↓ Cerebral perfusion: anxiety, confusion, agitation Anxiety Confusion Agitation Gastrointestinal ↓ Bowel sounds Nausea/vomiting 11/29/2019 17 Vinoli.S.G

18. HYPOVOLEMIC SHOCK Hypovolemic shock occurs when there is a loss of intravascular fluid volume. In hypovolemic shock, the volume is inadequate to fill the vascular space. The volume loss may be either an absolute or a relative volume loss. 11/29/2019 18 Vinoli.S.G

19. Absolute hypovolemia results when fluid is lost through hemorrhage, gastrointestinal (GI) loss (e.g., vomiting, diarrhea), fistula drainage, diabetes insipidus , hyperglycemia, or diuresis . In relative hypovolemia , fluid volume moves out of the vascular space into the extravascular space (e.g., interstitial or intracavitary space). This type of fluid shift is called third spacing . 11/29/2019 19 Vinoli.S.G

20. PATHOPHYSIOLOGY 11/29/2019 20 Vinoli.S.G

21. CLINICAL MANIFESTATION Increase in heart rate, CO, and respiratory rate and depth. The stroke volume and PAWP are decreased because of the decreased circulating blood volume. The patient may appear anxious and urine output will begin to decrease 11/29/2019 21 Vinoli.S.G

22. NEUROGENIC SHOCK Neurogenic shock is a hemodynamic phenomenon that can occur within 30 minutes of a spinal cord injury at the fifth thoracic (T5) vertebra or above and last up to 6 weeks. 11/29/2019 22 Vinoli.S.G

23. PATHOPHYSIOLOGY 11/29/2019 23 Vinoli.S.G

24. CLINICAL MANIFESTATION Hypotension Bradycardia inability to regulate temperature. (Initially, the patient's skin will be warm Later, the patient's skin may be cool or warm). absence of all voluntary and reflex neurologic activity below the level of the injury. 11/29/2019 24 Vinoli.S.G

25. ANAPHYLACTIC SHOCK Anaphylactic shock is an acute and life-threatening hypersensitivity (allergic) reaction to a sensitizing substance (e.g., drug, chemical, vaccine, food, insect venom). 11/29/2019 25 Vinoli.S.G

26. PATHOPHYSIOLOGY 11/29/2019 26 Vinoli.S.G

27. SIGNS & SYMPTOMS respiratory distress, because of laryngeal edema or severe bronchospasm , circulatory failure, because of massive vasodilation . sudden onset of symptoms, including Dizziness chest pain Incontinence swelling of the lips and tongue Wheezing stridor . Skin changes include Flushing pruritus , Urticaria Angioedema . anxious and confused and feel an impending sense of doom. 11/29/2019 27 Vinoli.S.G

28. SEPTIC SHOCK Septic shock is the presence of sepsis with hypotension despite fluid resuscitation along with the presence of tissue perfusion abnormalities. 11/29/2019 28 Vinoli.S.G

29. Diagnostic Criteria for Sepsis Infection General Variables • Fever (core temperature >100.9° F [38.3° C]) • Hypothermia (core temperature <97.0° F [36° C]) • Heart rate >90 beats/min • Tachypnea • Altered mental status • Significant edema or positive fluid balance (>20 ml/kg over 24 hr) • Hyperglycemia (blood glucose >120 mg/dl) in the absence of diabetes 11/29/2019 29 Vinoli.S.G

30. Inflammatory Variables • Leukocytosis (WBC count >12,000 cells/ml) • Leukopenia (WBC count <4000 cells/ml) • Normal WBC count with >10% immature forms • Elevated C-reactive protein 11/29/2019 30 Vinoli.S.G

31. Hemodynamic Variables • Arterial hypotension (SBP <90 mm Hg, MAP <70, or a decrease in SBP of >40 mm Hg) • SvO 2 >70% • Cardiac index >3.5 L/min/m 2 11/29/2019 31 Vinoli.S.G

32. Organ Dysfunction Variables • Arterial hypoxemia (PaO 2 /FIO 2 <300) • Acute oliguria (urine output <0.5 ml/kg/hr for at least 2 hr) • Coagulation abnormalities (INR >1.5 or PTT >60 sec) • Paralytic ileus (absent bowel sounds) • Hyperbilirubinemia (total bilirubin >4 mg/dl) 11/29/2019 32 Vinoli.S.G

33. Tissue Perfusion Variables • Hyperlactatemia (>1 mmol /L) • Decreased capillary refill or mottling 11/29/2019 33 Vinoli.S.G

34. PATHOPHYSIOLOGY 11/29/2019 34 Vinoli.S.G

35. CLINICAL MANIFESTATION Cardiovascular Chest pain Third spacing of fluid ↓/↑ Temperature Biventricular dilation: ↓ ejection fraction Pulmonary Swelling of lips and tongue Shortness of breath Edema of larynx and epiglottis Wheezing Rhinitis Stridor 11/29/2019 35 Vinoli.S.G

36. Skin Flushing Pruritus Urticaria Angioedema Warm and flushed → cool and mottled (late) Neurologic Anxiety Feeling of impending doom Confusion ↓ LOC Metallic taste 11/29/2019 36 Vinoli.S.G

37. Gastrointestinal Cramping Abdominal pain Nausea Vomiting Diarrhea 11/29/2019 37 Vinoli.S.G

38. STAGES OF SHOCK 11/29/2019 38 Vinoli.S.G

39. COMPENSATORY STAGE In the compensatory stage, the body activates neural, hormonal, and biochemical compensatory mechanisms in an attempt to overcome the increasing consequences of anaerobic metabolism and to maintain homeostasis. 11/29/2019 39 Vinoli.S.G

40. PROGRESSIVE STAGE The progressive stage of shock begins as compensatory mechanisms fail. Continued decreased cellular perfusion and resulting altered capillary permeability are the distinguishing features of this stage. 11/29/2019 40 Vinoli.S.G

41. Altered capillary permeability allows leakage of fluid and protein out of the vascular space into the surrounding interstitial space. In addition to the decrease in circulating volume, there is an increase in systemic interstitial edema. The patient may have anasarca , or diffuse profound edema. Fluid leakage from the vascular space also affects the solid organs (e.g., liver, spleen, GI tract, lungs) and peripheral tissues by further decreasing perfusion. 11/29/2019 41 Vinoli.S.G

42. REFRACTORY STAGE In the refractory stage, decreased perfusion from peripheral vasoconstriction and decreased CO exacerbate anaerobic metabolism. The accumulation of lactic acid contributes to an increased capillary permeability and dilation of the capillaries. Increased capillary permeability allows fluid and plasma proteins to leave the vascular space and move to the interstitial space. Blood pools in the capillary beds secondary to the constricted venules and dilated arterioles. The loss of intravascular volume worsens hypotension and tachycardia and decreases coronary blood flow. 11/29/2019 42 Vinoli.S.G

43. The patient in this stage of shock will demonstrate profound hypotension and hypoxemia. The failure of the liver, lungs, and kidneys will result in an accumulation of waste products, such as lactate, urea, ammonia, and carbon dioxide. The failure of one organ system will have an effect on several other organ systems. 11/29/2019 43 Vinoli.S.G

44. DIAGNOSTIC EVALUATION History collection Physical examination 12 lead ECG Continuous cardiac monitoring Chest X-ray Continuous pulse oximetry Hemodynamic monitoring 11/29/2019 44 Vinoli.S.G

45. LABORATORY STUDIES Test Result RBC, Hb & hematocrit Decreased Creatine kinase Increased Troponin Increased BUN Increased Creatinine Increased Glucose Increased Serum Electrolytes Sodium Potassium Increased Increased Arterial blood gases Respiratory alkalosis Metabolic acidosis Blood cultures Growth of organisms who are in septic shock Lactic acid Increased Liver enzymes (ALT, AST, GGT) Increased Urine Specific gravity Increased 11/29/2019 45 Vinoli.S.G

46. EMERGENCY MANAGEMENT Initial • Establish and maintain patent airway. • Administer high-flow oxygen (100%) by non- rebreather mask or bag-valve-mask. • Anticipate need for intubation and mechanical ventilation. • Stabilize cervical spine as appropriate. • Establish IV access with two large-bore catheters (14-16 gauge) and begin fluid resuscitation with crystalloids (e.g., normal saline solution). • Draw blood for laboratory studies (e.g., blood cultures, lactate, WBC). • Control any external bleeding with direct pressure or pressure dressing. • Assess for life-threatening injuries (e.g., pericardial tamponade , liver laceration, tension pneumothorax ). • Consider vasopressor therapy only after hypovolemia has been corrected. • Insert an indwelling bladder catheter and nasogastric tube. • Antibiotic therapy if sepsis is suspected. • Treat dysrhythmias . 11/29/2019 46 Vinoli.S.G

47. Ongoing Monitoring Level of consciousness. Vital signs, including pulse oximetry , peripheral pulses, capillary refill. Respiratory status. Cardiac rhythm. Urine output. 11/29/2019 47 Vinoli.S.G

48. Successful management of the patient in shock includes the following: 1. Identification of patients at risk for the development of shock 2. Integration of the patient's history, physical examination, and clinical findings to establish a diagnosis 3. Interventions to control or eliminate the cause of the decreased perfusion 4. Protection of target and distal organs from dysfunction 5. Provision of multisystem supportive care 11/29/2019 48 Vinoli.S.G

49. DRUG THERAPY dobutamine ( Dobutrex ) Positive inotropic effects dopamine ( Intropin ) vasopressor Drotrecogin alpha ( Xigris ) Anticoagulant effect by inhibiting factor Va / VIIIa Profibrinolytic and antiinflammatory properties epinephrine (Adrenalin) Low doses: -adrenergic agonist (cardiac stimulation, bronchial dilation, peripheral vasodilation ) High doses: -adrenergic agonist (peripheral vasoconstriction) 11/29/2019 49 Vinoli.S.G

50. hydrocortisone ( Solu-Cortef ) Decreases inflammation; reverses increased capillary permeability norepinephrine ( Levophed ) β 1 -Adrenergic agonist (cardiac stimulation) α-Adrenergic agonist (peripheral vasoconstriction) Renal/ splanchnic vasoconstriction phenylephrine (Neo- Synephrine ) α-Adrenergic agonist Vasoconstriction: renal, mesenteric, splanchnic , cutaneous , and pulmonary vessels 11/29/2019 50 Vinoli.S.G

51. sodium nitroprusside ( Nipride ) Arterial and venous vasodilation nitroglycerin ( Tridil ) Vasodilation vasopressin ( Pitressin [ Pressyn ]) Antidiuretic hormone, nonadrenergic vasoconstrictor 11/29/2019 51 Vinoli.S.G

52. Diuretics (e.g., furosemide ) Antibiotics as ordered Atropine (for bradycardia ) Antihistamines (e.g., diphenhydramine ) Bronchodilators: nebulized (e.g., albuterol ) Corticosteroids (if hypotension persists) 11/29/2019 52 Vinoli.S.G

53. FLUID THERAPY Crystalloids Isotonic • 0.9% NaCl (NSS) • Lactated Ringer's (LR) Fluid primarily remains in the intravascular space, increasing intravascular volume. Used for initial volume replacement in most types of shock. 11/29/2019 53 Vinoli.S.G

54. Hypertonic • 1.8%, 3%, 5% NaCl Fluid remains in the intravascular space, rapid volume expansion May be used for initial volume expansion in hypovolemic shock 11/29/2019 54 Vinoli.S.G

55. Blood/Blood Products • Whole blood/packed red blood cells • Fresh frozen plasma Replaces blood loss, increases oxygen-carrying capability. Replaces coagulation factors. All types of shock if hemoglobin is <12 g/dl (120 g/L) or if the patient does not respond to crystalloids. 11/29/2019 55 Vinoli.S.G

56. Colloids • Hetastarch ( Hespan ) • Human serum albumin (5%, 25%), plasma protein fraction (5% albumin in 500 ml NSS) • dextran Can increase plasma colloid osmotic pressure; rapid volume expansion 11/29/2019 56 Vinoli.S.G

57. SUPPORTIVE THERAPIES • Correct dysrhythmias • Correct the cause (e.g., stop bleeding, GI losses) • Use warmed fluids • Obtain cultures (e.g., blood, wound) before beginning antibiotics • Monitor temperature • Control blood glucose • Stress ulcer prophylaxis • Minimize spinal cord trauma with stabilization • Monitor temperature • Identify and remove offending cause • Prevention via avoidance of known allergens • Premedication with history of prior sensitivity (e.g., contrast media) 11/29/2019 57 Vinoli.S.G

58. NUTRITIONAL THERAPY Protein-calorie malnutrition is one of the primary manifestations of hypermetabolism in shock. Enteral nutrition should be initiated within the first 24 hours. parenteral nutrition is used if enteral feedings are contraindicated or fail to meet at least 80% of the patient's caloric A patient in shock should be weighed daily on the same scale at the same time of day. If the patient experiences a significant weight loss, dehydration should be ruled out before additional calories are provided. Large weight gains are common because of third spacing of fluids. Serum protein, nitrogen balance, BUN, serum glucose, and serum electrolytes are all used to assess nutritional status. 11/29/2019 58 Vinoli.S.G

59. NURSING DIAGNOSIS Ineffective tissue perfusion: renal, cerebral, cardiopulmonary, gastrointestinal, hepatic, and peripheral related to low blood flow or maldistribution of blood as evidenced by the following possible findings: • Renal urinary output <0.5 mg/kg/hr; ↑ BUN ↑ plasma creatinine , ↑ BUN/ creatinine ratio, ↑ urine specific gravity • Cerebral anxiety, confusion, agitation, altered mentation , ↓ LOC ↑ ↓ temperature • Cardiopulmonary: ↓ BP, orthostatic hypotension, tachycardia; dysrhythmias , ↓ CVP and PAWP weak, thready pulses; flat neck veins; tachypnea , ↓ S p O 2 crackles; ↑ ventilation-perfusion mismatch, refractory hypoxemia, respiratory failure • Gastrointestinal: ↓ bowel sounds, paralytic ileus , hyperglycemia or hypoglycemia • Hepatic: ↑ liver enzymes (e.g., ALT, AST, GGT), ↑ NH 3 and lactate • Peripheral: ↓ peripheral pulses, cool and clammy skin, decreased capillary refill, pallor or cyanosis 11/29/2019 59 Vinoli.S.G

60. Fear; related to of condition as evidenced by verbalization of anxiety about condition and fear of death, or withdrawal with no communication; restlessness; sleeplessness; increase in heart and respiratory rate 11/29/2019 60 Vinoli.S.G

61. NURSING INTERVENTIONS Monitor vital signs, orthostatic blood pressure, mental status, and urinary output to assess trends in patient's condition and evaluate patient's response to treatment . • Monitor trends in hemodynamic parameters (e.g., CVP, PAP, PAWP) to assess patient's status and detect fluid deficits or excesses and to evaluate patient's response to treatment . • Administer fluids to maintain blood pressure and cardiac output . • Monitor laboratory evidence of inadequate tissue perfusion (e.g., increased lactic acid levels, decreased arterial pH levels) to assess trends in patient's status and evaluate patient's response to treatment . 11/29/2019 61 Vinoli.S.G

62. Monitor determinants of tissue oxygen delivery (e.g., PaO 2 , SpO 2 , ScvO 2 SvO 2 , hemoglobin levels, cardiac output) to assess trends in patient's status and evaluate patient's response to treatment . Monitor for symptoms of respiratory failure (e.g., low PaO 2 , elevated PaCO 2 levels, respiratory muscle fatigue) to plan respiratory interventions . Monitor fluid status, including intake and output, to evaluate response to treatment . Monitor renal function (e.g., BUN, Cr levels) to evaluate response to treatment . Provide oxygen therapy and/or mechanical ventilation to maximize oxygenation and maintain SpO 2 ≥ 90% . Monitor blood glucose levels, as indicated, to maintain normal levels . 11/29/2019 62 Vinoli.S.G

63. • Monitor for symptoms of inadequate coronary artery perfusion (e.g., ST changes on ECG or angina). • Promote optimal preload to improve contractility while minimizing heart failure (e.g., administer nitroglycerin and maintain PAWP within prescribed range). • Promote coronary artery perfusion (e.g., maintain mean arterial pressure and control tachycardia) to prevent myocardial ischemia >60 mm Hg • Remove stimuli precipitating neurogenic reaction to control symptoms . 11/29/2019 63 Vinoli.S.G

64. • Administer antibiotics, antihistamines, epinephrine, and antiinflammatory drugs, if appropriate, to control symptoms . • Monitor the patient closely for hemorrhage. • Note hemoglobin/ hematocrit level before and after blood loss to evaluate response to treatment . • Administer blood products (e.g., platelets or fresh frozen plasma) to replace lost volume . 11/29/2019 64 Vinoli.S.G

65. • Seek to understand the patient's perspective of a stressful situation to validate patient's feelings . • Use a calm, reassuring approach. • Listen attentively. • Administer medications if appropriate to reduce anxiety . 11/29/2019 65 Vinoli.S.G

66. Stay with patient to promote safety and reduce fear . • Control stimuli for patient needs to reduce patient's anxieties and oxygen need . • Provide factual information concerning diagnosis, treatment, and prognosis to reduce patient's fear of the unknown and assist patient in making informed decisions . • Encourage family to stay with patient to reduce anxiety level . 11/29/2019 66 Vinoli.S.G

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