[Spinal anaesthesia for caesarean section: fluid loading, vasopressors and hypotension].

OBJECTIVE: To analyze the different preventive and curative strategies for the management of hypotension during spinal anaesthesia for caesarean section.

DATA SOURCES: Data related to hypotension during spinal anesthesia for caesarean section were searched in the Medline database. Trials published in English or French were reviewed.

DATA SYNTHESIS: Hypotension during caesarean section under spinal anaesthesia is very frequent (55 to 90%) if not prevented. It can induce complications for the mother and/or the fetus. Crystalloid preload alone is ineffective. Colloid preload is effective but might be better used as a second line treatment. Ephedrine has been the vasopressor of choice for long, but has a weak prophylactic efficacy. In addition, it can induce maternal cardiovascular adverse effects and fetal acidosis. Prophylactic phenylephrine, with or without ephedrine according to maternal heart rate, is at least as effective as ephedrine, with less adverse effects. Crystalloid loading at the time of spinal injection ("co-/post-loading") enhances the haemodynamic control provided by vasopressors.

CONCLUSION: Hypotension during spinal anesthesia for caesarean section must be systematically detected, prevented and treated without delay. The association of vasopressor(s) (phenylephrine with or without ephedrine) with a rapid crystalloid loading at the time of spinal injection represents the most interesting strategy nowadays.