This paper reviews and discusses three controversial subjects regarding treatment of intraoperative
nausea and other complications experienced by patients undergoing cesarean delivery under
spinal anesthesia: (1) the administration of supplemental
oxygen, (2) prophylactic vasopressors and (3) the use of low-dose combined spinal
epidural anesthesia (CSE). While not universally acknowledged, recent data suggest that the routine administration of supplemental
oxygen to normal-weight, healthy patients undergoing elective cesarean delivery is unnecessary, especially when spinal
hypotension is minimized. Supplemental
oxygen administration does not prevent intraoperative or
postoperative nausea and vomiting. Additionally, although higher inspired
oxygen fractions modestly increase fetal oxygenation, they also cause a concomitant increase in
oxygen free radical activity in both mother and fetus, which may weaken the infant's ability to withstand subsequent neonatal insult. The use of prophylactic vasopressor infusions may benefit some patients, but parenteral preanesthetic
ephedrine administration is not warranted. Heart rate variability guided
therapy could help identify patients at risk for developing severe
hypotension after
spinal anesthesia. High-dose
phenylephrine infusion in conjunction with rapid co-hydration is efficient, but is unfortunately associated with a relatively high incidence of maternal
bradycardia.
Oxygen, fluid administration and prophylactic vasopressors may not be the
solution to
hypotension,
nausea and
vomiting associated with
spinal anesthesia during cesarean delivery. Lower dose
spinal anesthesia as part of a CSE technique reduces the incidence of maternal
hypotension, and in our opinion is the best option currently available.