COMPLICATIONS OF REGIONAL ANESTHESIA

Hypotension

Hypotension is present when systolic blood pressure decreases to less than 100 mm Hg or to more than 20% less than baseline readings, and it occurs in many patients after placement of neuraxial anesthesia. The incidence and severity of hypotension depend on the height of the block, the position of the parturient, and whether prophylactic measures were taken to avoid such hypotension. Measures that decrease the risk of hypotension to varying degrees include intravenous administration of fluids, avoidance of aortocaval compression (left uterine displacement), and vigilant monitoring of blood pressure at frequent intervals after placement of a regional anesthetic. In addition, FHR evaluation is helpful so that any adverse effects on the fetus can be corrected if possible. If recognized and treated promptly, transient maternal hypotension should not be associated with maternal or neonatal morbidity. ^[198] As previously discussed, although intravenous ephedrine in 5- to 10-mg increments remains the first-line treatment, recent evidence supports the use of phenylephrine.^[41] The prophylactic administration of commonly used doses of ephedrine does not appear to be of benefit. ^{[199] [200]}