Page 217 - TNFlipTest

Toronto Notes 2019 Medical Emergencies
Hypertensive Urgency
• definition:severelyelevatedBP(usuallysBP>180,dBP>110)withnoevidenceofend-organdamage • mostoftencausedbynon-adherencetoprescriptions
• treatment:re-initiateantihypertensivetherapy,acuteBPreductionnotindicated
• goal:differentiatehypertensiveemergenciesfromhypertensiveurgencies
Emergency Medicine ER37
Table 22. Commonly Used Agents for the Treatment of Hypertensive Crisis
With CNS manifestations of severe HTN,
it is often difficult to differentiate causal relationships (i.e. HTN could be secondary to a cerebral event with an associated Cushing reflex)
Drug
VASODILATORS
Sodium Nitroprusside (vascular smooth muscle dilator) 1st line
Nicardipine
(CCB)
Fenoldopam Mesylate (dopamine receptor antagonist)
Enalapril (ACEI) Nitroglycerin Hydralazine
Dosage
0.25-10 μg/kg/min
2 mg IV bolus, then 4 mg/kg/h IV
0.05-0.1 μm/kg/min IV
0.625-1.25 mg IV q6h 5-20 μg/min IV
5-10 mg IV/IM q20min (max 20 mg)
Onset of Action
Immediate
15-30 min
<5 min
15-30 min 1-2 min 5-20 min
5-10 min
1-2 min
1-2 min
Duration of Action
3-5 min
40 min
8-10 min
12-24 h 3-5 min 2-6 h
3-6 h
10-20 min
3-10 min
Adverse Effects*
N/V, muscle twitching, sweating, cyanide intoxication, coronary steal syndrome
Tachycardia, headache, flushing, local phlebitis (e.g. encephalopathy, renal failure, eclampsia, sympathetic crisis)
Tachycardia, headache, nausea, flushing
(e.g. acute RF)
Theoretical fall in pressure in high renin states not seen in studies
Hypotension,
bradycardia, headache, lightheadedness, dizziness
Dizziness, drowsiness, headache, tachycardia, Na+ retention
Vomiting, scalp tingling, burning in throat, dizziness, nausea, heart block, orthostatic hypotension
Hypotension, nausea, bronchospasm
Tachycardia, headache, flushing
Special Indications
Most hypertensive emergencies (especially CHF, aortic dissection)
Use in combination with β-blockers (e.g. esmolol) in aortic dissection Caution with high ICP and azotemia
Most hypertensive emergencies
Caution with acute CHF
Most hypertensive emergencies
Caution with glaucoma
Acute LV failure
Avoid in acute MI, pregnancy, acute RF
MI/pulmonary edema Eclampsia
Most hypertensive emergencies (especially eclampsia)
Avoid in acute CHF, heart block >1st degree
Aortic dissection, acute MI SVT dysrhythmias, perioperative HTN
Avoid in acute CHF, heart block >1st degree
Catecholamine excess (e.g. pheochromocytoma)
ADRENERGIC INHIBITORS
Labetalol
Esmolol
Phentolamine
20 mg IV bolus q10min or 0.5-2 mg/min
250-500 μg/kg/min
1 min, then 50 μg/kg/min for 4 min; repeat
5-15 mg q5-15min
*Hypotension may occur when using any of these agents
Acute Coronary Syndrome
• seeCardiologyandCardiacSurgery,C27
• definition:newonsetofchestpain,oracuteworseningofpreviouschestpain,orchestpainatrestwith:
■ negative cardiac biomarkers and no ECG changes = Unstable angina (UA)
■ positivecardiacbiomarkers(elevatedtroponin)andNSTEMI(orECGchangeswithoutSTelevation) ■ positive cardiac biomarkers (elevated troponin) and ST segment elevation on ECG = STEMI
• investigations
■ ECG STAT (as soon as history suggests possible ACS), troponin (2-6 h after symptom onset), CXR
(to rule out other causes of the patient's presentation) • management
■ stabilize: ABCs, oxygen, IV access, cardiac monitors, oximetry
■ ASA 162-325 mg chewed and swallowed
■ nitroglycerin 0.3 mg SL q5min x 3; IV only if persistent pain, CHF, or hypertensive
◆ contraindications: hypotension, phosphodiesterase inhibitor use, right ventricular infarctions (1/3 of all inferior MIs)