Care of Patients with Shock Chapter 39 Care of Patients with Shock

Shock Widespread abnormal cellular metabolism that occurs when the human need for oxygenation and tissue perfusion is not met to the level needed to maintain cell function. “Whole-body” response. Shock is a “syndrome.” Any problem that impairs oxygen delivery to tissues and organs can start the syndrome of shock and lead to a life-threatening emergency.

Classification of Shock by Functional Impairment Hypovolemic shock Cardiogenic shock Distributive shock Obstructive shock

Classification of Shock by Origin of the Problem Hypovolemic Cardiogenic Basogenic Septic

Processes of Shock Initial stage (early shock) Nonprogressive stage (compensatory stage) Progressive stage (intermediate stage) Refractory stage (irreversible stage)

Review of Oxygenation and Tissue Perfusion Total blood volume Cardiac output Size of the vascular bed

Hypovolemic Shock Occurs when low circulating blood volume causes a mean arterial pressure decrease; the body’s oxygen need is not met Commonly caused by hemorrhage (external or internal) and dehydration S&P

Cardiogenic Shock Actual heart muscle is unhealthy, and pumping is directly impaired. Myocardial infarction is the most common cause of direct pump failure.

Distributive Shock Blood volume is not lost but is distributed to the interstitial tissues where it cannot circulate and deliver oxygen Caused by loss of sympathetic tone, blood vessel dilation, pooling of blood in venous and capillary beds, capillary leak Neural-induced distributive shock Chemical-induced distributive shock

Chemical-Induced Distributive Shock Anaphylaxis Sepsis Capillary leak syndrome

Obstructive Shock Caused by problems that impair the ability of the normal heart muscle to pump effectively Heart is normal, but conditions outside the heart prevent either adequate filling of the heart or adequate contraction of the healthy heart muscle Pericarditis Cardiac tamponade

Stages of Shock Initial stage Nonprogressive stage Progressive stage Refractory stage

Initial Stage of Shock Baseline MAP decreased by less than 10 mm Hg Heart and respiratory rate increased from the baseline or a slight increase in diastolic blood pressure Adaptive responses of vascular constriction and increased heart rate

Nonprogressive Stage MAP decreases by 10 to 15 mm Hg. Kidney and hormonal adaptive mechanisms activated. Tissue hypoxia in nonvital organs. Acidosis and hyperkalemia. Stopping conditions that started shock and supportive interventions can prevent shock from progressing.

Progressive Stage of Shock Sustained decrease in MAP of more than 20 mm Hg from baseline. Vital organs develop hypoxia. Life-threatening emergency. Immediate interventions are needed. Conditions causing shock need to be corrected within 1 hour of the onset of the progressive stage.

Refractory Stage of Shock Too much cell death and tissue damage result from too little oxygen reaching the tissues. Body can no longer respond effectively to interventions, and shock continues.

Multiple Organ Dysfunction Syndrome Sequence of cell damage caused by the massive release of toxic metabolites and enzymes. Metabolites released from dead cells. Microthrombi form. MODS occurs first in the liver, heart, brain, and kidney. Myocardial depressant factor from the ischemic pancreas.

Health Promotion and Maintenance Primary prevention of hypovolemic shock Secondary prevention of hypovolemic shock

Physical Assessment/Clinical Manifestations Cardiovascular changes Pulse Blood pressure Oxygen saturation Skin changes Respiratory changes Renal and urinary changes Central nervous system changes Musculoskeletal changes

Assessment Psychosocial assessment Laboratory tests

Nonsurgical Management Goals of shock management are to maintain tissue oxygenation, increase vascular volume to normal range, and support compensatory mechanisms Oxygen therapy IV therapy Drug therapy

Drug Therapies Vasoconstrictors, such as dopamine, epinephrine, norepinephrine, phenylephrine Agents that enhance contractility Agents that enhance myocardial perfusion

Sepsis and Septic Shock Complex type of distributive shock—usually begins as a bacterial or fungal infection and progresses to a dangerous condition over a period of days Sepsis—widespread infection coupled with a more general inflammatory response, known as systemic inflammatory response syndrome (SIRS), that is triggered when an infection escapes local control

Severe Sepsis Progression of sepsis with an amplified inflammatory response

Septic Shock Stage of sepsis and SIRS when multiple organ failure is evident and uncontrolled bleeding occurs. Even with appropriate intervention, the death rate among patients in this stage of sepsis exceeds 60%.

Septic Shock (Cont’d) Etiology and genetic risk Incidence/prevalence Health promotion and maintenance

Septic Shock: Clinical Manifestations Cardiovascular changes Respiratory changes Skin changes Renal urinary changes Psychosocial assessment Laboratory tests

Septic Shock: Interventions Oxygen therapy Drug therapy Blood replacement therapy

Community-Based Care Home care management Health teaching