ABC | Volume 114, Nº4, April 2020

Statement Luso-Brazilian Position Statement on Hypertensive Emergencies – 2020 Arq Bras Cardiol. 2020; 114(4)736-751 Table 4 – Flowchart from the 7 th Brazilian Guideline of Arterial Hypertension for clinical and laboratory diagnosis of cases of pheochromocytoma and paraganglioma Clinical findings Suspected diagnosis Additional studies - Paroxysmal hypertension with headache, sweating, and palpitations - Resistant hypertension Pheochromocytoma - Free plasma metanephrines - Urinary metanephrines and serum catecholamines - Imaging tests urine), increase in preexisting proteinuria, clinical or laboratory abnormality characteristic of preeclampsia, or elevation in preexisting BP levels after the 20 th gestational week in a patient with chronic hypertension. 11.1. Treatment The two main key points in the treatment of HC in pregnancy are (1) stabilization of the mother, including the use of antihypertensive medications that are safe and appropriate for use in pregnancy, and delivery recommendation; and (2) fetal well-being, which must be confirmed by fetal monitoring and ultrasound. Pharmacological treatment should be initiated at BP levels > 150/100 mmHg, aiming at maintaining the levels at 130 to 150/80 to 100 mmHg (degree of recommendation [DR]: IIa; level of evidence [LE]: B). In patients with preeclampsia in stable clinical condition without the need for immediate delivery, oral antihypertensive treatment is indicated. 72 In Brazil, the oral medications that are usually administered are methyldopa, hydralazine, calcium-channel antagonists (long- acting nifedipine, amlodipine), and beta-blockers (preferably pindolol). Pregnant women with chronic hypertension may continue the use of thiazides, as long as they do not promote volume depletion. 73 The use of renin-angiotensin system blockers is contraindicated in pregnancy (DR: I; LE: B). 72 Urgent pharmacological treatment is indicated in severe hypertension (SBP > 155 to 160 mmHg) and in the presence of premonitory signs (DR: I; LE: B). Intravenous hydralazine is recommended (5 mg, repeat 5 to 10 mg every 30 minutes to a maximum of 20 mg). Sodium nitroprusside may be considered for urgent BP control, especially in the presence of APE and severe and refractory hypertension. 72 Magnesium sulfate is the medication of choice for both treatment and prevention of seizures during eclampsia. The patient should be monitored in terms of urine output, patellar reflexes, respiratory rate, and oxygen saturation. Plasma magnesium should be maintained between 4 and 7 mEq/L and measured in the occurrence of renal disease. If magnesium sulfate intoxication is suspected, calcium gluconate should be administered. 70,71 12. Adrenergic Emergencies Neuroendocrine tumors associated with sympathetic tissue with the potential to secrete catecholamines are rare and include pheochromocytomas (adrenal medulla) and paragangliomas (non-adrenal tissue). Diagnosis, location, and anatomical delineation of these tumors involve measurement of catecholamines and their metabolites in blood and urine, computed tomography and/or magnetic resonance imaging, and metaiodobenzylguanidine (I¹²³) scintigraphy. Symptoms may occur at any stage of life, are nonspecific, and depend on the release of catecholamines into the bloodstream; BP elevation, palpitations, and headache may occur. Surgical removal of these tumors is always indicated to cure or prevent cardiovascular disease secondary to catecholamine excess. 74 BP in these patients may be sustained or paroxysmal, and a marked increase in BP may characterize an impending life- threatening HE. This occurs by activation of alpha receptors by catecholamines. The Brazilian Guideline on Hypertension recommends a diagnostic flowchart for neuroendocrine tumors (pheochromocytoma and paragangliomas), which is shown in Table 4. 75 Figure 4 shows the imaging methods used for diagnostic confirmation in the occurrence of an abnormal biochemical test. Whole-body scintigraphy is obtained to identify the location of extra-adrenal neuroendocrine tumors (paragangliomas). This test is recommended in cases of abnormal biochemical tests and negative imaging tests. It should always be performed after verification and discontinuation of medications that may interfere with their interpretation (sympathomimetics, calcium-channel blockers, cocaine, antidepressants, and labetalol), which should be suspended 14 days prior to the test. Whole-body scintigraphy is contraindicated during pregnancy. 76 After a diagnosis of neuroendocrine tumor, the proposed treatment is always surgical, preceded by pharmacological preparation and hydration to prevent or mitigate the occurrence of HC or hypotension during surgery (Table 5). 76 In this situation, intravenous antihypertensive medications are administered (initially alpha-blockers and later beta-blockers). Continuous infusion of sodium nitroprusside (0.25 to 10 mg/kg/min) or phentolamine (continuous infusion of 1 to 5 mg with a maximum dose of 15 mg) may be used with markedly increased BP. 75-77 13. Illicit Drugs and Hypertensive Emergency In the emergency room, patients with HC and sympathetic hyperactivity should raise suspicion of amphetamine or cocaine intoxication, as well as abusive use of other drugs like serotonin reuptake inhibitors, monoamine oxidase inhibitors, and use of cytotoxic or antiangiogenic medications. 52 Cocaine has multiple cardiovascular and hematological effects that contribute to BP elevation, development of myocardial ischemia, and/or AMI due to coronary vasoconstriction. Cocaine, even in small doses, blocks norepinephrine and dopamine reuptake in presynaptic adrenergic terminals, causing catecholamine accumulation in the postsynaptic receptor, thus acting as a powerful sympathomimetic agent. 78 As a result, cocaine causes a dose-dependent increase in heart rate and BP. 79 In addition, cocaine use may reduce left ventricular function associated with increased parietal stress at the end of systole and increased oxygen demand. The chronotropic effects of 746