11 Hypertensive Emergencies, part 2 Flashcards
Presentation of acute renal failure
patients may have
- peripheral edema
- oliguria
- loss of appetite
- nausea and vomiting
- orthostatic changes
- confusion
Elevated serum creatinine confirms the diagnosis
therapeutic goal for acute renal faiulre
reduce BP by no more than 20% acutely
Antihypertensive agents that are all suitable for acute hypertension-induced isolated renal failure
Fenoldopam (improves natriuresis and creatinine clearance)
Nicardipine
Clevidipine
These reduce systemic vascular resistance while preserving renal blood flow
Drugs to avoid in acute renal failure
Nitroprusside, as it results in cyanide and thiocyanate toxicity.
ACE inhibitors (in acute failure)
therapeutic goal for preeclampsia
Aim for SBP <140 mm Hg in the first hour
preferred agents for preeclampsia
hydralazine
labetalol
nifedipine
How to administer hydralazine
10 mg SIVP (max initial dose is 20 mg)
repeat every 4 -6 h as needed
AVOID in patients with myocardial ischemia, pulmonary edema, and aortic dissection. Reflex tachy increases myocardial demand
How to administer labetalol?
bolus: 10-20 mg IV over 2 mins;
may administer 40-80 mg at 10-min intervals,
up to 300 mg total dose
infusion: initially, 2 mg/min; titrate to response up to 300 mg total dose, if needed
may cause fetal bradycardia
risk in patients with asthma, COPD, and heart failure
remarks on labetalol
combined selective a1- adrenergic and non-selective B-adrenergic receptor blocker
a- to B-blocking ratio of 1:7
safe in pregnancy
4 settings in which an excess of catecholamines can result in a hypertensive emergency
a.k.a. “Acute Sympathetic Crisis”
- abrupt discontinuation of oral or transdermal clonidine
this withdrawal syndrome is potentiated by concomitant B-blocker therapy due to unopposed a-mediated vasoconstriction - pheochromocytoma
- Sympathomimetic drugs (e.g., cocaine, amphetamines, MAOI toxicity)
- autonomic dysfunction (d/t spinal cord or severe head injury or abn such as spina bifida)
Therapy goals for acute sympathetic crisis
Reduce excessive sympathetic drive
Symptomatic relief
Aim for SBP <140 mm Hg int he first hour
How to manage acute sympathetic crisis
In general, IV benzodiazepine (BZD) is first-line to decrease adrenergic stimulation
If BZD is ineffective, add nitroglycerine or phentolamine
calcium channel blocker is 3rd-line
For patients with pheochromocytoma in hypertensive emergency, IV phentolamine is first-line
first-line agent for cocaine-induced hypertension
benzodiazepines
drugs given in pheochromocytoma
IV phentolamine is first-line for patients with pheochromocytoma in hypertensive emergency
Phenoxybenzamine is a long-acting oral adrenergic a-receptor blocker, used only in the preoperative setting in patients who are hypertensive but not in crisis
For patients who have undergone fibrinolysis/thrombolysis for acute ischemic stroke, the BP goal for the first 24 hours is _______
≤180/105
(In contrast to the goal prior starting thrombolysis which is ≤185/110)
