CURRENT Essentials of Critical Care.pdf

Chapter 9 Cardiology 123Hypertensive Crisis & Malignant Hypertension■ Essentials of Diagnosis• Hypertensive crisis: blood pressure 240/130 or hypertensionwith comorbid condition requiring urgent control: angina, heartfailure, cerebral hemorrhage, edema• Malignant hypertension: severe hypertension with end-organdamage such as papilledema, encephalopathy, renal failure• Irritability, headache, visual changes, nausea, confusion, chestpain, seizures• Tachycardia, retinal hemorrhage or exudates, neurologic deficits• Azotemia, disseminated intravascular coagulation• Hematuria, red cell casts, proteinuria• ECG: left ventricular hypertrophy, ischemic changes■ Differential Diagnosis• Accelerated essential hypertension• Renovascular disease: renal artery stenosis• Pheochromocytoma• Acute glomerulonephritis• Collagen vascular disease• Food/drug interaction with monoamine oxidase inhibitor■ Treatment• Rapid reduction of blood pressure with short-acting titratableagents: nitroprusside, labetalol, esmolol, nitroglycerin• Nitroprusside drug of choice; monitor thiocyanate levels after24 hours of infusion especially in renal failure• Labetalol or esmolol drip: utilize with underlying coronaryartery disease• ACE inhibitors: use in heart failure, myocardial infarction• Nitroglycerin: primarily venodilator; variable blood pressure reduction;indicated for myocardial ischemia and heart failure• Hydralazine: used as bridge from intravenous to oral medications• Phentolamine preferred if pheochromocytoma suspected• Hemodialysis can help with blood pressure control• Assess degree of end-organ damage based on symptoms: headCT, renal ultrasound, echocardiogram■ PearlOverly aggressive blood pressure reduction, especially in the case ofan acute stroke, may lead to further cerebral ischemia and infarctionsecondary to impaired cerebral autoregulation.ReferencePhillips RA et al: Hypertensive emergencies: diagnosis and management. ProgCardiovasc Dis 2002;45:33. [PMID: 12138413]