0071643192.pdf

■ Maintenance fluids: Calculate maintenance fluids (see Table 1.15)

and add to deficit replacement.

■ Solution:Use D5.25 NS (D5^1 / 4 NS) for infants and D5.45 NS

(D5^1 / 2 NS) in children.

■ Treatment of the underlying cause should be simultaneous.

A 22-year-old previously healthy male presents to the ED complaining of

flulike symptoms and progressive shortness of breath. On examination

he appears ill with BP 80/50, HR 120, RR 30 and T 38.0ºC. He has evi-

dence of poor perfusion, bilateral rales, and jugular venous distention. Bedside

cardiac ultrasound shows diffuse hypokinesis. What is the best initial manage-

ment of this patient?

This patient is in cardiogenic shock from acute myocarditis. The goal of

treatment is to improve myocardial contractility and pump function. Ensuring

adequate ventilation and oxygenation is the first step in management, followed

by the initiation of dopamine or dobutamine (if SBP > 90 mmHg) to improve

pump function.

Cardiogenic Shock

Occurs when a primary cardiac disorder results in a decrease in cardiac output

to a level that is insufficient to meet tissue demands for oxygen.

Cardiac output is determined by HR and stroke volume.

CO (L/min) = HR (beats/min) ×SV (L/beat)

Stroke volume is itself determined by the interrelation of preload, afterload, and

contractility. Problems in any of the determinants of CO may cause cardiogenic

shock.

ETIOLOGY

Etiologies include:

■ Classically thought of as pump failure from myocardial injury or

dysfunction: Myocarditis, cardiomyopathy, ischemia, infarct, contusion

■ Arrhythmias

RESUSCITATION

TABLE 1.15. Calculating Maintenance Fluids

PATIENTWEIGHT DAILYMAINTENANCEFLUIDS

For the first 0–10 kg 100 mL/kg/day

For the next 10–20 kg 50 mL/kg/day

From 20–70 kg 20 mL/kg/day

Deficit fluids (in liters) = Add up total mL and divide by 24 to obtain hourly rate.

% fluid loss ×weight in kg.

Replace one-half the deficit

over first 8 hours, the rest over

the next 16 hours.

Acute MI is the most common

cause of cardiogenic shock.