ECG, electrocardiogram; LE, lower extremity; ICU, intensive care un it; IV, intravenous;

PND, paroxysmal nocturnal dyspnea.

0.4 mg every 5 minutes. Severe exacerbations warrant IV

nitroglycerin infusions. Start at a rate between 20 and 50

meg/min and rapidly increase in increments of 20-40

meg/min every 5-10 minutes. Titrate the infusion to

symptomatic relief or systemic hypotension. Consider

nitroprusside in patients who don't adequately respond, as

it is a more potent arterial vasodilator. It is important to

ask any patient requiring vasodilator therapy about the

current use of phosphodiesterase-S inhibitors (eg,

sildenafil, used in erectile dysfunction and pulmonary

hypertension), as the combination of agents may lead to

life-threatening drops in systemic blood pressure. Avoid

overaggressive vasodilation in patients with r ight ventricular infarction, aortic stenosis, and hypertrophic cardiomy ­

opathy, as all are preload dependent conditions.

Initiate IV loop diuretics (eg, furosemide) in all

patients with signs of volume overload. Furosemide is

not only a potent diuretic but also an effective venodilator, often producing symptomatic improvement long

before the onset of diuresis. Start the dosing at 40 mg IV

in patients naive to the drug, whereas those who take the

agent chronically should have their home dose doubled.

Evaluate patients who fail to diurese within 30 minutes

for any evidence of urinary obstruction and re-dose as

necessary. Bumetanide, torsemide, and ethacrynic acid

are alternative loop diuretics, with ethacrynic acid being

the agent of choice in patients with a history of severe

sulfa allergy.

A summary of medications used to treat acute CHF

exacerbations is listed in Table 15-1.

CONGESTIVE HEART FAILURE

Table 1 5-1. Med ications used in CHF.

Dosing Titration

Vasodilators

Nitroglycerin 0.4 mg SL Repeat q 3-5 min to

sublingual symptoms

Nitroglycerin IV 25-50 meg/min Titrate by 1 0-20 meg/min

q 3-5 min to symptoms.

Max: 400 meg/min

Nitroprusside IV 1 0-20 meg/min Titrate by 5-10 mcgjmin

q 5 min

Max: 400 meg/min

Loop Diuretiu

Furosemide 40-80 mg IV May re-dose at 30 min if no

diuresis, then q 12 hour

dosing

Max: 200 mg/ dose

Bumetanide 1 mg IV May re-dose at 2 hours

Torsemide 10 mg IV May re-dose at 2 hours

Ethacrynic acid 50 mg IV May be re-dosed at 8 hours

lnotropesjPressors

Dobutamine 2-5 meg/kg/min Titrate to effect,

Max: 20 meg/kg/min

Dopamine 3-5 meg/kg/min Titrate to effect,

Max: 20 meg/kg/min

Norepinephrine 2-5 meg/min Titrate to effect,

Max: 30 meg/min

Mechanism of

Action

Preload reduction

Preload reduction;

some afterload

reduction at

higher doses

Marked afterload