Management of hypertensive crises in the el(6)

3 Clinical manifestations

Many elderly patients with severe uncontrolled HTN are totally asymptomatic. Pinna and collaborators, in a study of 1,546 patients (mean age = 69 years) presented with acute hypertensive crises, reported that 55.6% of the patients referred non-specific symptoms such as dizziness, palpitations, and headache.[18]Whereas symptoms related to end-organ damage, such as chest pain and focal neurologic deficits, were evident in 28.3% and 16.1% of patients, respec-tively.[18]Elderly patients are more likely to have hypertensive emergencies, rather than urgencies, than the general population.[13]

The most frequent end-organ damage associated with hypertensive emergencies are cerebral infarction, acute pulmonary edema, and hypertensive encephalopathy (24%, 23%, and 16%, respectively).[2]

4 Management

The management of hypertensive crises in elderly re-quires prompt understanding of the pathophysiology of the disease, the physiological changes among them, and me-chanism of action and side effects of the medications available (See Table 1). Most experts advise to generally reduce the mean arterial pressure by approximately 10%–15% during the first hour, and another 10%–15% during the next 2 to 4 hours due to the risk of hypoperfusion if the BP is lowered too suddenly or too far (e.g., into the range of < 140/90 mmHg).[19–21]However, faster drop in BP is required in certain conditions, such as aortic dissection, in which BP should be kept between 100 and 120 mmHg systolic and less than or equal to 60 to 70 mmHg diastolic as fast as possible.[20,22,23]While in the acute phase of ischemic stroke, it has been recommended that lowering of BP should be delayed unless BP is > 220/120 mmHg or > 200/100 mmHg with end organ damage or if the patient will receive thrombolytics.[24]In hemorrhagic stroke, the target BP is variable but generally systolic blood pressure (SBP) can be reduced safely to￡140 mmHg.[25]The INTERACT2 trial showed that a rapid decrease of BP does not have a representative reduction in primary outcome of mortality or severe disability in patients with an acute intracerebral hemorrhage, however, their analysis of modified Rankin scores revealed that patients had a better functional outcome when their BP was intensively decreased.[26]

Table 1. Pharmacokinetics of different medications used in the management of hypertensive crises in the (s)DosageOnsetHalf-life NitroglycerinActivation of guanylyl cyclase via NO5 to 200 μg/min2–5 min1–4 min NitroprussideActivation of guanylyl cyclase via NO0.3 to 10 mcg/kg/min< 2 min–2 min Nifedipine1st generation dihydropyridine calcium-channel blocker10 to 20 mg 3 times daily–20 min2.5–5 h Nicardipine1st generation dihydropyridine calcium-channel blocker5–25 mg/h5–15 min4–6 h Clevidipine3rd generation dihydropyridine calcium-channel blocker1–2 mg/h Increase every 10 min up to 16 mg/h2–4 min5–15 min LabetalolSelective α1-adrenergic receptor blocker and nonselective β-adrenergic blocker200–400 mg per o.s. every 2–3 h30–120 min2–6 h EsmololBeta1 receptor –1 mg/kg loading dose. 50–300 μg/kg/min infusion60 s20 min ClonidineAlpha2 adrenergic agonist and imidazoline I1 receptor agonist500 μg/kg in bolus and 25–300 μg/kg/min30 min12–16 h FenoldopamDopamine type-1 receptor –1.6 μg/Kg/ min5–10 min5 min HydralazineInhibition of calcium influx in vascular smooth muscle cells20 mg initial bolus; 20–80 mg repeat boluses5–15 min3 h

Regardless of the target BP, the pharmacological management must include agents that are titratable and easily reversible. The choice of the medications also depends on the patient’s comorbidities, availability, and end-organ involvement (Table 2).

Table 2. Specific indications and adverse effects of different drugs used in the management of acute hypertension in the IndicationsAdverse Effects NitroglycerinAcute coronary syndrome, pulmonary edema, volume overloadHeadache, vomiting reflex tachycardia and methemoglobinemia NitroprussideUse only in the elderly when other alternatives are not availableThiocyanate and cyanide intoxication, coronary steal syndrome NifedipineNot recommended in the elderly patientHypotension, coronary steal syndrome, reflex tachycardia NicardipineMost hypertensive crises as a potent vasodilatorHeadache, local phlebitis, vomiting ClevidipineMost hypertensive crisesHeadache, tachycardia, heart failure LabetalolAcute aortic dissectionHeart block and bronchoconstriction EsmololPost-operative hypertension, useful in increased cardiac output, easily titrationHeart block and heart failure ClonidineSevere hypertension associated with pain and anxietyRebound hypertension and sedative effects FenoldopamRenal arterial disease, glomerulonephritis or vascular diseases with impaired renal function, very usefulHeadache, tachycardia, nausea and exacerbation of glaucoma HydralazineNot recommended in elderly patientsReflex tachycardia and severe hypotension

In patients presenting with hypertensive urgencies, a less drastic approach can be considered. Some authors suggest a decrease of BP over a period of 24–48 hours with an oral short-acting agent, such as angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker, followed by close monitoring of the patient for several hours.[1,21]

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