Emergency states The State Education Institution of Higher Professional Training The First Sechenov Moscow State Medical University under Ministry of Health of the Russian Federation Lecture presentation Professor Pirozhkov S.V. Department of Pathophysiology education year

Collapse – acute severe decrease in systemic blood pressure due to rapidly developing incongruity between the volume of circulating blood and the capacity of the vascular bed

TYPES OF COLLAPSE BY ORIGIN cardiogenic orthostatic hypovolemic vasodilatory ● postinfarction ● arrhythmic ● cardiomyopathic ● posthemorrhagic ● dehydrationary ● toxico-infectious ● hyperthermic ● toxico-infectious ● psychogenic

Shock is the state in which failure of the circulatory system to maintain adequate tissue perfusion results in widespread reduction in delivery of O 2 and nutrients to cells

CLASSIFICATION OF SHOCK 1. HYPOVOLEMIC decrease in CPV decrease in SV and CO shock 2. CARDIOGENIC decrease in myocardial contractility decrease in CO (cardiac index < 1.8 L/min/m 2 ) shock 3. EXTRACARDIAC OBSTRUCTIVE increased pericardial pressure impaired ventricular diastolic filling decrease in SV and CO shock 4. DISTRIBUTIVE considerable increase in the peripheral vascular capacity discrepancy between the perfusion pressure and the demand of tissues and organs in blood flow, despite N or increased CO shock stroke volume cardiac output circulating plasma volume

ADAPTIVE REACTIONS AT THE NONPROGRESSIVE STAGE OF SHOCK ► Activation of the sympathetic nervous system by: - baroreceptor reflex - low-pressure vascular stretch receptors - central nervous system ischemic response (when BP < 50 mm Hg) ► Activation of the renin-angiotensin-aldosterone mechanism ► Increased secretion of vasopressin by the posterior pituitary ► Activation of mechanisms that return the blood volume back toward normal: - increased absorption of water from the intestinal tract - conservation of water and salt by the kidneys - thirst and increased appetite for salt

IMPORTANT FACTORS THAT CAUSE IRREVERSIBLE CHANGES IN THE PROGRESSING SHOCK Ischemia of tissues, O 2 and substrate deficiency Acidosis Activation of endothelial cells Activation of leukocytes Excessive, uncontrolled release of inflammatory mediators and active oxygen species (О 2 -, ОН*) Progressively developing and extending inflammatory process Massive injury to cellular membranes Intense release of lysosomal enzymes Widespread depletion of the cellular energy stores

TYPES OF DISTRIBUTIVE SHOCK ● Neurogenic shock - deep general anesthesia - spinal anesthesia - brain damage in concussion or contusion ● Pain shock ● Anaphylactic shock ● Drug overdose shock ● Adrenal shock (Addisonian crisis) ● Septic shock

Heart failure Shock Deterioration of the heart function in shock Ventricular diastolic pressure Pressure gradient for coronary perfusion Ischemia Heart rate Diastolic compliance

THE MOST COMMON CAUSES OF COMA ■ Wide-spread damage in both hemispheres (ischemia, trauma etc.). ■ Suppression of cerebral function by extrinsic drugs, toxins, hypoxia, internal metabolic derangements (hypoglycemia, azotemia, hepatic failure etc.). ■ Brainstem lesions that cause proximate damage to the reticular activating system (RAS).