Focus the history on elucidating the cause and effect (if any) of hypertension in the child. First and foremost, ascertain use of hypertensive medication as sudden withdrawal of medication can lead to pathologic increase in blood pressures. Numerous studies have demonstrated substantial usage of and safety of angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), and calcium-channel blockers in pediatric patients with essential hypertension. Although generally considered safe, these medicines have the same potential complications in children as they do in adults.6 A full medication history of both prescription and recreational drugs is important; oral contraceptives and steroids as well as cocaine and amphetamines can cause elevated pressures. Birth history indicating problems such as umbilical artery catheterization as well as with chronic lung disease risk factors for high blood pressure. Renal disease can be both cause and effect of elevated pressures. Thus, ask about symptoms of renal disease, specifically gross hematuria, edema, generalized fatigue, and recent infections. Endocrine problems can cause symptoms in addition to hypertension such as flushing, tachycardia and weight changes. It is especially important in the obese patient to inquire about sleep disturbance as sleep-disordered breathing is associated with hypertension.
The effects of elevated blood pressures on the pediatric patient can be quite vague. The kidneys can be profoundly affected by prolonged high pressures with few signs. Symptoms are more often recognized in the cardiovascular and neurologic systems. Chest pain, exertional dyspnea, and palpitations can occur. Ask about a history of headaches, visual disturbances, and in more severe cases, altered mental status and seizures.
Carefully look for clues to the etiology and the effects of high blood pressure. Pay attention to the vital signs. Blood pressure measurements should be performed in both upper extremities and at least in one lower extremity. Leg pressures should measure at least 10 to 20 mm Hg higher than arm pressures and, if not, could signify coarctation of the aorta. Tachycardia can point toward an endocrine etiology, whereas bradycardia can signify increased intracranial pressure and impending herniation. After vital signs, the most important part of the physical examination is the neurologic examination, especially in the younger child, as altered mental status can be a cause or a result of pathologically elevated pressures. Fundoscopic examination should be attempted to look for elevated intracranial pressure as well as signs of long-term hypertension. Examination of the cardiovascular system includes checking pulses in all four extremities, evaluation for murmurs and gallops, as well as location of the cardiac apex.
Other physical findings can provide important clues. Adenotonsillar hypertrophy causes sleep disturbance that can lead to hypertension. Signs of heart failure should be noted, such as pulmonary edema or hepatomegaly. Edema in the lower extremities or periorbitally can indicate renal disease. Evaluate the skin for striae, flushing, acne, hirsutism, and acanthosis nigricans, all of which are signs of endocrine abnormalities. Young children should also undergo a urogenital examination to evaluate for ambiguous genitalia.
Two things must be accomplished in the ED: the initiation of testing for the etiology and for end-organ damage and deciding whether the child requires admission or can be safely discharged with follow-up (Fig. 43-2). The results of initial screening examinations can help with this decision. An electrocardiogram, a CBC, and a basic metabolic panel as well as urinalysis and urine culture should be done on every patient with blood pressures >95th percentile prior to deciding disposition from the ED. Electrocardiogram can show left ventricular hypertrophy in the cases of prolonged or severe hypertension and can be a useful tool for deciding whether a child requires more urgent reduction in blood pressure. Electrolytes can evaluate for mineralocorticoid function and an elevated glucose, in the setting of obesity, can point toward diabetes with primary hypertension. BUN and creatinine are vital, as acute renal failure and numerous parenchymal and glomerular kidney disorders can cause hypertension. A CBC should be performed to look for signs of anemia and infection.
Algorithm for the assessment of pediatric hypertension.
If a child is admitted with hypertensive urgency or emergency, consider obtaining other tests that the child will require for the workup. These tests include rennin levels, plasma and urine steroids, plasma and urine catecholamines, drug screening, and heavy metal levels, if deemed appropriate. Clearly, if the child shows signs of neurologic dysfunction, a head CT scan is mandatory. Patients with severe hypertension will need an echocardiogram, but if the child is not in extremis and has neither critical valvular disease nor aortic coarctation, this can be completed as part of the inpatient evaluation.