Hypotension after spinal anesthesia for cesarean section: how to approach the iatrogenic sympathectomy

Hypotension during cesarean section remains a frequent complication of spinal anesthesia and is associated with adverse maternal and fetal events.

Despite ongoing research, no single measure for sufficient treatment of spinal-induced hypotension was identified so far. Current literature discusses the efficacy of low-dose spinal anesthesia, timing and solutions for adequate fluid therapy and various vasopressor regimens. Present guidelines favor the use of phenylephrine over ephedrine because of decreased umbilical cord pH values, while norepinephrine is discussed as a probable superior alternative with regard to maternal bradycardia, although supporting data is limited. Alternative pharmacological approaches, such as 5HT3-receptor antagonists and physical methods may be taken into consideration to further improve hemodynamic stability.

Current evidence favors a combined approach of low-dose spinal anesthesia, adequate fluid therapy and vasopressor support to address maternal spinal-induced hypotension. As none of the available vasopressors is associated with relevantly impaired maternal and fetal outcomes, none of them should be abandoned from obstetric practice. Rapid crystalloid co-loading is of equivalent efficacy as compared with colloids and should be preferred because of a more favorable risk profile.