Hypertensive emergencies in children.

Hypertensive emergencies, though uncommon in children, are potentially life threatening. While targeting blood pressure reduction to below the 90th percentile for age, gender and height, mean arterial blood pressure should be gradually lowered by one-fourth of the planned reduction over 8-12 h, a further fourth over the next 8-12 h, and the final 50% over the 24 h after that. Frequent invasive or non-invasive blood pressure monitoring is essential, as is monitoring for sensorial alteration and loss of papillary reflexes. Few antihypertensive agents have been examined in children. Continuous intravenous infusions of short acting drugs such as nitroprusside, labetalol and nicardipine are preferred to intravenous boluses of hydralazine or diazoxide. If severe symptoms are absent, oral agents such as nifedipine, clonidine, minoxidil, hydralazine, labetalol, captopril, and prazosin may be used. Nicardipine and labetalol are particularly suited in emergencies with intracranial bleeding or ischemic stroke, while furosemide, sodium nitroprusside and nitroglycerine are useful in congestive cardiac failure. Therapy with oral antihypertensive drugs should be instituted within 6-12 h of parenteral therapy, and the latter gradually withdrawn over the next 12-48 h. Oral agents have limited application as primary therapy, except when administration of intravenous infusion is likely to be delayed. This article provides a summary of the clinical approach to evaluation and management of severe symptomatic hypertension in children.