Caesarean anaesthesia: spinal, CSE, general anaesthesia and spinal hypotension

Meet the patient

A 32-year-old in labour at 39 weeks has a non-reassuring CTG and is called for Category 1 caesarean. She has a working epidural that has been topping up slowly through the second stage. The registrar asks: top up the epidural, or convert to general anaesthetic? The answer depends on how reliably the block will build in the minutes you have — and whether you have a failed-intubation plan if it does not.^[1]

Two sentences frame the entire topic: phenylephrine is first-line because it gives better neonatal acid-base than ephedrine, and Category 1 does not excuse an unplanned airway. Everything below is the craft behind those two statements.^[1][6]

References9ShowHide

1. [1]Lee A, Ngan Kee WD, Gin T A quantitative, systematic review of randomized controlled trials of ephedrine versus phenylephrine for the management of hypotension during spinal anesthesia for cesarean delivery Anesth Analg, 2002.PMID 11916798
2. [2]Cooper DW, Carpenter M, Mowbray P, et al. Fetal and maternal effects of phenylephrine and ephedrine during spinal anesthesia for cesarean delivery Anesthesiology, 2002.PMID 12459688
3. [3]Ngan Kee WD, Khaw KS, Ng FF Comparison of phenylephrine infusion regimens for maintaining maternal blood pressure during spinal anaesthesia for Caesarean section Br J Anaesth, 2004.PMID 14977792
4. [4]Ngan Kee WD, Khaw KS, Tan PE, et al. Placental transfer and fetal metabolic effects of phenylephrine and ephedrine during spinal anesthesia for cesarean delivery Anesthesiology, 2009.PMID 19672175
5. [5]Singh PM, Singh NP, Reschke M, et al. Vasopressor drugs for the prevention and treatment of hypotension during neuraxial anaesthesia for Caesarean delivery: a Bayesian network meta-analysis of fetal and maternal outcomes Br J Anaesth, 2020.PMID 31810562
6. [6]Mushambi MC, Kinsella SM, Popat M, et al. Obstetric Anaesthetists' Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics Anaesthesia, 2015.PMID 26449292
7. [7]Palmer CM, Emerson S, Volgoropolous D, et al. Dose-response relationship of intrathecal morphine for postcesarean analgesia Anesthesiology, 1999.PMID 9952150
8. [8]Carvalho JC, Balki M, Kingdom J, et al. Oxytocin requirements at elective cesarean delivery: a dose-finding study Obstet Gynecol, 2004.PMID 15516392
9. [9]WOMAN Trial Collaborators Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial Lancet, 2017.PMID 28456509