GENERAL ANAESTHESIA FOR CAESAREAN DELIVERY IN WOMEN WITH CLASS 3 OBESITY – A RETROSPECTIVE STUDY FROM THE NORTH-WEST OF ENGLAND

A. ASHOUR, K. BHATIA, M. COLUMB ON BEHALF OF GROUP OF OBSTETRIC ANESTHETISTS OF LANCASHIRE, GREATER MANCHESTER, AND MERSEY (GOAL-GM) STUDY COLLABORATORS

Introduction:

▪ Women with class 3 obesity (body mass index [BMI] ≥ 40 kg.m-2 ) are at increased risk of requiring a caesarean delivery (CD). ¹

▪ Though regional anaesthesia (RA) is the preferred technique, a general anaesthetic (GA) may need to be administered during CD.

Methods:

▪ We retrospectively reviewed electronic records of 56 (7.4%) of the 760 women with booking BMI ≥ 40 kg.m-2 who had a GA for CD across nine maternity units in the North-West of England between 1 st of October 2022 to 30th of September 2023 .

▪ Our aims were to evaluate the GA technique utilised for CD, and airway complications during induction including ascertaining incidence of oxygen (SpO2 ) desaturation (< 94%) and difficult (> 2 attempts) or failed intubation in this cohort.

Results:

▪ The mean (SD) BMI in the cohort was 44.2 (6.2) kg. m-2 whilst the mean age was 30.6 (5.8) years.

▪ A BMI 40-49 kg.m-2 was recorded in 51 (91.1%), 50-59 kg.m-2 in 4 (7.1%) whilst > 60kg.m-2 was recorded in 1 (1.8%)

▪ GA was administered to 26 (46.4%), 15 (26.8%) and 15 (26.8%) for category (Cat) 1, 2-3 and 4 CDs respectively.

▪ Propofol as induction agent was utilised in 44 (78.6%), opioid predelivery in 29 (51.8%), whilst rocuronium use was documented in 38 (67.9%) women.

▪ No cases of failed intubation or can’t-intubate, can’t oxygenate were observed in our cohort.

▪ Difficult intubation was recorded in one (1.8%; 95%CI 0.0, 9.6) woman having Cat 1 CD.

Discussion:

• Our findings indicate that desaturation was observed in 25% (95%CI 14.4, 38.4) of women with class 3 obesity.

• Face mask oxygenation technique was the most employed technique for pre-oxygenation.

• Difficult intubation incidence during GA for CD was 1 in 56 in women with class 3 obesity, which is in line with that reported in the literature. ²

• Face mask-only oxygenation technique use significantly increased whilst video-laryngoscopy use declined as urgency of CD increased.

• Significant variations in the pre-oxygenation and the anaesthetic technique are common in women with class 3 obesity.

• Propofol use was associated with lower risk of desaturation in women with class 3 obesity.

• Standardising the GA technique in women with class 3 obesity may be useful to decrease airway complications and enhance preparedness in managing difficult intubation in this cohort.

References:

1. Chu SY, Kim SY, Schmid CH, et al. Maternal obesity and risk of cesarean delivery: a meta‐analysis. Obes Rev 2007; 8:385–94. https://doi.org/10.1111/j.1467-789X.2007.00397.x

2. Reale SC, Bauer ME, Klumpner TT et al; Multicenter Perioperative Outcomes Group Collaborators. Frequency and Risk Factors for Difficult Intubation in Women Undergoing General Anesthesia for Cesarean Delivery: A Multicenter Retrospective Cohort Analysis. Anesthesiology 2022; 136:697-708. doi: 10.1097/ALN.0000000000004173