Per-operative cerebral near-infrared spectroscopy (NIRS) predicts maternal hypotension during elective caesarean delivery in spinal anaesthesia.
BACKGROUND
Spinal anaesthesia-induced maternal hypotension is common during elective caesarean section. This study evaluated whether cerebral near-infrared spectroscopy predicts maternal hypotension, defined as a 25% reduction in systolic blood pressure or heart rate or presentation of clinical symptoms.


METHODS
Thirty-eight ASA I-II parturients scheduled for elective caesarean section with spinal anaesthesia were monitored by near-infrared spectroscopy for changes in cerebral oxygenation (ScO(2)) with the recordings blinded to the anaesthesiologist.


RESULTS
There was a 5% decrease in ScO(2) (median 8%, interquartile range 5-11%) in all 22 patients who developed hypotension, whereas only 2 of 13 women who did not develop hypotension had a 5% decrease in ScO(2). Median time from a 5% decrease in ScO(2) to hypotension was 81 (interquartile range 30-281) s. The sensitivity of near-infrared spectroscopy to predict hypotension was 1.00, with a specificity 0.85 and a predictability of 0.91.


CONCLUSIONS
The results demonstrate a relationship between ScO(2) and impending hypotension during low-dose spinal anaesthesia for elective caesarean section. We suggest that immediate measures are taken to stabilise blood pressure if the near-infrared spectroscopy determined cerebral oxygenation decreases by more than 5%.
Berlac
P A
PA
Department of Anaesthesia, Hvidovre Hospital, University of Copenhagen, Denmark. peter.berlac@dadlnet.dk
Rasmussen
Y H
YH
D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D001921:Brain / Q000378:metabolism*; D002585:Cesarean Section; D017558:Elective Surgical Procedures; D004809:Ephedrine / Q000494:pharmacology; D005260:Female; D006801:Humans; D007022:Hypotension / Q000175:diagnosis*; D007431:Intraoperative Complications / Q000175:diagnosis*; D010100:Oxygen / Q000378:metabolism*; D011247:Pregnancy; D019265:Spectroscopy, Near-Infrared
D004809:Ephedrine; D010100:Oxygen