Choice of anaesthesia for category‐1 caesarean section in women with anticipated difficult tracheal intubation: the use of decision analysis

Abstract

SummaryA predicted difficult airway is sometimes considered a contra-indication to rapid sequence induction of general anaesthesia, even in an urgent case such as a category-1 caesarean section for fetal distress. However, formally assessing the risk is difficult because of the rarity and urgency of such cases. We have used decision analysis to quantify the time taken to establish anaesthesia, and probability of failure, of three possible anaesthetic methods, based on a systematic review of the literature. We considered rapid sequence induction of general anaesthesia with videolaryngoscopy, awake fibreoptic intubation and rapid spinal anaesthesia. Our results show a shorter mean (95% CI) time to induction of 100 (87-114) s using rapid sequence induction compared with 9 (7-11) min for awake fibreoptic intubation (p < 0.0001) and 6.3 (5.4-7.2) min for spinal anaesthesia (p < 0.0001). We calculate the risk of ultimate failed airway control after rapid sequence induction to be 21 (0-53) per 100,000 cases, and postulate that some mothers may accept such a risk in order to reduce potential fetal harm from an extended time interval until delivery. Although rapid sequence induction may not be the anaesthetic technique of choice for all cases in the circumstance of a category-1 caesarean section for fetal distress with a predicted difficult airway, we suggest that it is an acceptable option.

The obstetric difficult airway: if we can't predict it, can we prevent it?

“…The failure rate is low, approximately 1–2% , although there is a 5% chance for airway compromise secondary to local anaesthetic use. For the category 1 cesarean section though, awake fibreoptic intubation is not an apt choice considering the estimated 7–11 min it takes to secure the airway . We suggest that this time range, based on a personal communication between the authors and an airway expert, may be an underestimate.…”

“…Krom et al, in this issue of Anaesthesia, use an operational research model to determine the optimum solution in this scenario . By constructing a decision tree, they analyse three alternative management approaches (rapid sequence induction with videolaryngoscopy; awake fibreoptic intubation; and spinal anaesthesia), and show that videolaryngoscopy is associated with a significantly shorter time to successful readiness for surgery, with a low overall failure rate of 21 per 100,000 cases.…”

Anesthesia Considerations in Emergency C-Section and Perioperative Neonatal Resuscitation: A Case Report and Review of Literature

“…They calculated the risk of ultimate failed airway control after rapid sequence induction to be 21 (0 -53) per 100,000 cases, and postulate that some mothers may accept such a risk in order to reduce potential fetal harm from an extended time interval until delivery. Although rapid sequence induction may not be the anesthetic technique of choice for all cases in the circumstance of a category-1 caesarean section for fetal distress with a predicted difficult airway, they suggest that it is an acceptable option [7].…”

Accuracy, intra- and inter-rater reliability of three scoring systems for the glottic view at videolaryngoscopy

“…Future work should assess how these scores, especially the Fremantle Score, correlate with the occurrence of difficult or failed intubation. The routine and simple recording of view, ease and device would help provide clarity to clinically difficult areas of videolaryngoscopic use such as urgent caesarian section requiring general anaesthesia by facilitating the collection of registry data.…”