Anesthetic Considerations in Hypertensive Emergencies in Pregnant Patients

Abstract

SUMMARY H ypertension is one of the most important chronic medical conditions affecting approximately one billion people worldwide (Lloyd-Jones et al., 2010). It is defined by the 7th Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) as Blood Pressure above 140/90 mm Hg for most and above 130/80 mm Hg for diabetics and chronic kidney disease patients (Egan et al., 2010). Hypertensive disorders in pregnancy (HDP) are associated with severe maternal obstetric complications and are a leading contributor to maternal mortality (Berg et al., 2010). Furthermore, HDP lead to preterm delivery, fetal intrauterine growth restriction, low birth weight and perinatal death. Hence, promoting quality services and enhancing communication among the providers who provide health care to pregnant women, including obstetricians, family practice physician, emergency department physicians, midwives, anesthesiologists, nurses and others became mandatory (Roberts et al., 2003). Hypertensive emergency (crisis) is characterized by a severe elevation in blood pressure (> 180/120 mm Hg) complicated by evidence of impending or progressive target organ dysfunction, manifested by clinical sequelae or diagnostic test abnormalities. It requires immediate intervention with parenteral therapy and admission to a monitored setting (Chobanian et al., 2003). A pregnant patient could experience a hypertensive emergency as sequelae of: Pregnancy itself (eclampsia/severe pre-eclampsia), essential hypertension, renal disease such as: pyelonephritis, glomerulonephritis, systemic lupus erythematosus, renal artery stenosis, drugs either due to abrupt withdrawal of a centrally acting α2-adrenergic agonist (clonidine, methyldopa) or Phencyclidine, cocaine or other sympathomimetic drug intoxication, or interaction with monoamine oxidase inhibitors, endocrinal disease such as: pheochromocytoma, primary aldosteronism, glucocorticoid excess, renin-secreting tumors, thyrotoxic crisis, and finally, central nervous system disorders such as: cerebrovascular accidents (infarction/hemorrhage) and head injury (Polgreen et al., 2015). The American College of Obstetrician and Gynecologists have classified the hypertensive disorders of pregnancy into the following four categories: 1. Pre-eclampsia is defined as the triad of hypertension, proteinuria and generalized edema, developing after the 20th week of gestation. 2. Chronic hypertension is the presence of sustained hypertension prior to pregnancy and continuing throughout the pregnancy. 3. Superimposed pre-eclampsia implies the development of increased blood pressure, proteinuria, and/or edema in a gravida with chronic hypertension. 4. Transient gestational hypertension refers to development of hypertension without proteinuria or edema in a previously normotensive gravida followed by return to normotension within 10 days postpartum.