Chapter 19 Shock Elsevier items and derived items

Chapter 19 Shock Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 1

Definition of Shock • Inadequate tissue perfusion resulting in impaired cellular metabolism • Deprives cells of essential oxygen and nutrients, forcing cells to rely on anaerobic (without oxygen) metabolism • Less energy is produced and lactic acid, a byproduct of anaerobic metabolism, causes tissue acidosis and subsequent organ dysfunction Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 2

Hypovolemic Shock • Inadequate blood volume to maintain the supply of oxygen and nutrients to body tissues • Intravascular or circulating volume deficits can occur from external or internal losses • Blood volume falls with excessive blood or fluid loss, inadequate fluid intake, or a shift of plasma from the blood vessels into body tissues/organs • Causes of blood/fluid loss: hemorrhage, severe diarrhea or vomiting, excessive perspiration • Excessive shift of plasma with pathologic states (burns, peritonitis, and intestinal obstruction) Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 3

Cardiogenic Shock • Occurs when heart fails as a pump • Decreased myocardial contractility causes decreased cardiac output and impaired tissue perfusion • Difficult to treat and usually results when diseased coronary arteries cannot meet the demand of the working myocardial cells • Causes include conditions that result in ineffective myocardial cell function, such as dysrhythmias, cardiomyopathy, myocarditis, valvular disease, and structural disorders Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 4

Distributive Shock • The problem is not loss of blood, but excessive dilation of blood vessels or decreased vascular resistance causing the blood to be improperly distributed • Anaphylactic • Septic • Neurogenic Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 5

Effects of Shock on Body Systems and Functions • • • Respiratory system Cardiovascular system Neuroendocrine system Immune system Gastrointestinal system Renal system Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 6

Early, Reversible, and Compensatory Stages • Symptoms • Mental status • Irritability, restlessness • Blood pressure • Normal or slightly decreased, decreasing pulse pressure, orthostatic hypotension • Pulse • Increased 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 stimulation • Respirations • Increased rate and depth Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 7

Early, Reversible, and Compensatory Stages • Urine output • Decreased • Skin • Cool and pale • Exception: warm and dry with septic shock • Abdomen • Decreased bowel sounds • Blood glucose • Increased • Other • Thirst Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 8

Intermediate (Progressive) Stage • Symptoms • Mental status • Listlessness, confusion • Blood pressure • Decreased; narrow pulse pressure • Pulse • Weak and thready, tachycardia, dysrhythmias • Respirations • Increased, deep, crackles present on auscultation Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 9

Intermediate (Progressive) Stage • Temperature • Subnormal, except with septic shock • Urine output • Decreased; possible renal failure • Skin • Cold, pale, clammy, slow capillary refill, cyanosis • Other • Dry mouth, thirst, sluggish pupillary response, peripheral edema, and muscle weakness Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 10

Irreversible (Refractory) Stage • Symptoms • Mental status • Loss of consciousness • Blood pressure • Systolic continues to fall; diastolic approaches zero • Pulse • Progressive slowing, irregular • Respirations • Slow, shallow, irregular • Urine output • Minimal • Skin • Cold, clammy, cyanosis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 11

Diagnosis • Based on history and physical examination • Tests and procedures that help establish type of shock, stage, and the cause • Blood and urine studies, measurement of hemodynamic pressures, chest radiograph, ECG and continuous cardiac monitoring, pulse oximetry and arterial blood gases, and urine output Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 12

Oxygenation • Brain cells begin to die after 4 minutes without oxygen, and oxygen consumption increases as delivery decreases in shock: poor prognosis • Oxygen delivery such as increasing arterial oxygen saturation, hemoglobin, and cardiac output • Supplemental oxygen may be used or mechanical ventilation may be necessary • Paralytics, sedatives, and analgesics may be ordered to decrease oxygen requirements Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 13

Fluid Replacement • Normal saline is usually administered initially • Subsequent fluids may include various crystalloids and colloids depending on situation • Crystalloids provide replacement water and electrolytes for all fluid compartments • Colloids remain in the vascular system and draw fluid into the bloodstream • Especially important when large amounts of plasma proteins have been lost Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 14

Pharmacologic Therapy • Based on manipulation of the cardiac dynamics: contractility, preload, afterload, and heart rate • No one drug will provide nutrients and oxygen to the cells; several agents assist in manipulation of the four circulatory components Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 15

Figure 19 -1 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 16

Figure 19 -2 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 17

Assessment • Continuous monitoring of cardiac rate and rhythm; blood pressure; body temperature; hemodynamic values; respiratory rate, rhythm, and depth; and arterial blood gases • Observe skin color; palpate for warmth and moisture • Note pupil size, equality, and response to light • Describe patient’s level of consciousness and response to commands, and assess reflexes • Auscultate heart, lung, and bowel sounds Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 18

Assessment • Observe movement of the chest wall with respirations; inspect and palpate abdomen for distention • Palpate for bladder distention, and note the appearance of urine and the hourly output • Inspect the extremities for color, and palpate for peripheral pulses and edema • Inspect IV infusion sites for pallor, swelling, or coolness that suggests extravasation Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 19

Nursing Diagnosis • The primary nursing diagnosis for all patients in shock is Altered Tissue Perfusion • May be related to alteration(s) in circulating blood volume, myocardial contractility, blood flow, or vascular resistance Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 20

• • • Decreased Cardiac Output Disturbed Thought Processes and Anxiety Deficient Fluid Volume Risk for Injury Risk for Infection Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 21

Systemic Inflammatory Response Syndrome (SIRS) • Generalized inflammation that threatens vital organs • Conditions that can lead to SIRS are shock, multiple transfusions, massive tissue injury, burns, and pancreatitis • Effects are damage to the endothelium of blood vessels and a hypermetabolic state • Hypotension, microemboli, and shunting of blood flow compromise organ perfusion • The hypermetabolic state is characterized by increased serum glucose, which eventually depletes carbohydrate, fat, and protein stores Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 22

Diagnosis • Diagnosis 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 bpm • Respiratory rate more than 20/min, or Paco 2 less than 32 mm Hg • WBC count less than 4000 cells/mm 3 or more than 12, 000 cells/mm 3, or more than 10% immature (band) neutrophils Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 23

Medical Treatment and Nursing Interventions • • Prevent and treat infection Maintain tissue oxygenation Provide nutritional and metabolic support Support failing organs Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 24