Page 241 - Critical Care Notes

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■ Stimulation of the adrenal medulla → release of epinephrine and norepi-
nephrine → cell metabolism changes from aerobic to anaerobic → lactic
acidosis.
■ Cardiac hypoperfusion → ventricular failure.
■ Cerebral hypoperfusion → failure of sympathetic nervous system, cardiac
and respiratory depression, and thermoregulatory failure.
■ Respiratory depression → ↑ pulmonary capillary membrane permeability →
pulmonary vasoconstriction → acute respiratory failure and ARDS.
■ Renal hypoperfusion → acute tubular necrosis → acute renal failure.
■ GI hypoperfusion → failure of GI organs.
■ MODS is failure of two or more body systems → death.
Clinical Presentation

■ SBP <90 mm Hg. MAP <70 mm Hg and cardiac index <2.2 L/min/m 2 ,
pulmonary wedge pressure >18 mm Hg, and systemic vascular resistance
>1,400 dynes/sec/cm -5 in cardiogenic shock. Hypotension indicates
>30% blood volume loss.
■ ↑ HR, weak and thready pulse, narrowing of pulse pressure, dysrhythmias,
absent peripheral pulses, dysrhythmias, chest pain.
■ Delayed capillary refill and flat jugular veins. Distended neck veins are seen
in cardiogenic shock.
■ Altered mental status, confusion, altered level of consciousness (LOC) →
lethargy and unconsciousness or unresponsiveness.
■ Hypoxemia and respiratory alkalosis initially from RR and ↑ depth of respi-
rations → respiratory distress → respiratory failure → respiratory and meta-
bolic acidosis. Crackles or wheezing may also be present.
■ Oliguria progressing to anuria, and ↑ urine osmolarity and specific gravity.
Urine is dark and concentrated.
■ ↑ BUN and creatinine.
■ Pale and cool skin progressing to ashen, cold-clammy to cyanotic, mottled,
and diaphoretic skin.
Hemodynamic Effects

Type of Shock Preload Afterload Cardiac Output
Cardiogenic ↑ ↑ ↓
Hypovolemic ↓ ↑ ↓
Distributive ↓ ↑↓ ↓↑

MULTISYS