Thread by @akhadilkarMD

As a Cardiology fellow, we get a lot of consults for hypertensive urgency/emergency.

Part 3A: Therapy

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Therapy:
- The presence of acute/rapidly progressive end-organ damage and not the absolute BP determines whether the situation is an emergency
- Goals should be based on mean arterial pressure (MAP) with close monitoring in ICU setting with arterial line

Therapy:
- In general, should reduce no more than 25% of MAP in the first 24 hours; after this time will be more gradual and allow auto-regulatory mechanisms to reset
- Exceptions: more aggressive BP reduction in aortic dissection, post-operative bleeding, and pulmonary edema

1) Sodium Nitroprusside:
- Drug of choice for most hypertensive emergencies due to favorable hemodynamic profile, rapid onset, and rapid cessation of action
- Direct smooth muscle relaxant, decreased preload & afterload (arteriolar dilator & increases venous capacitance)

1) Sodium Nitroprusside:
- Leads to decrease in MAP, afterload, & preload
- Can improve renal function if cardiac output improves
- Does not raise intra-cranial pressure or cause headaches
- Very rapid onset of action; effect stops within 1-5 minutes of stopping infusion

1) Sodium Nitroprusside:
- Side-effects: RBC and muscle cells metabolize nitroprusside to cyanide, which is converted to thiocyanate in the liver and excreted in the urine.
- Thiocyanate levels increase in renal insufficiency
- Cyanide accumulates in hepatic disease

2) Labetalol
- Alpha & beta-blocker, relatively long duration of action
- Decreases SVR, MAP, and HR with little change in cardiac output
- No effect on cerebral vasculature
- Begins to lower blood pressure in 5 minutes; effects last 1-3 hours after cessation

2) Labetalol
- Should not give in acutely decompensated HF, cardiogenic shock, bradycardia, 2nd/3rd degree AV block, or reactive airway disease
- Should not use w/o alpha-blockade with heightened adrenergic tone (pheochromocytoma)

3) Nitroglycerin
- Important in the setting of myocardial ischemia, acute MI, and acute cardiopulmonary edema
- Primarily a venodilator
- Decreases preload & afterload, decreases myocardial O2 demand, dilates epicardial coronary arteries, inhibits vasospasm

3) Nitroglycerin
- Favorably redistributes blood to the endocardium
- Should not be used in patients w/ high ICP
- Can develop tachyphylaxis with increased BP after prolonged administration and can have tachycardia from reflex sympathetic activation

*Not to use for medical advice and always discuss with your fellow or attending*

These are 3 common drugs in your toolbox to help treat hypertensive urgency/emergency on the exams and in real life. Let me know what you think! Stay tuned for part 3B on therapies!