Monitored Anesthesia Care versus General Anesthesia for Intrauterine Fetal Interventions: Analysis of Conversions and...

Fetal intervention/surgery constitutes a relatively new field of maternal-fetal medicine in which monitored anesthesia care (MAC) or general anesthesia (GA) are utilized as anesthetic techniques when feasible. In this study, we sought to calculate the usage of MAC and GA in various fetal procedures as well as investigate any anesthetic complications and conversions from MAC to GA.

All intrauterine fetal intervention cases performed at the Texas Children's Hospital Pavilion for Women from 2012 to 2016 were retrospectively analyzed and categorized by mode of anesthesia. Anesthetic complications, conversions to GA, preoperative patient physical status, average number of intraoperative medications required, and average duration of procedure were compared between the MAC and GA groups.

A total of 480 fetal interventions were performed with 432 under MAC (90%) and 37 under GA (7.7%). There were 11 conversions from MAC to GA (2.3%). These conversions were due to poor visualization with ultrasound and change of surgical approach to laparoscopic-assisted technique (n = 5), inability to lay flat due to back pain (n = 3), persistent vomiting (n = 2), and unresponsiveness after a spinal block (n = 1). One anesthetic complication occurred due to a medication administration error and did not require conversion to GA. The average preoperative American Society of Anesthesiologists (ASA) physical status classification was 1.97 for the MAC group and 1.87 for the GA group (p = 0.23). Duration of the interventions averaged 129 min under MAC and 138 min under GA (p = 0.23). An average of 7.8 different medications were administered during MAC cases compared to 13.1 during GA cases (p < 0.0001).

This analysis suggests that MAC is the most commonly used anesthetic option for fetal interventions with a low complication rate and minimal conversion rates to GA. It is therefore preferable to use MAC when feasible due to the low complication rate and decreased drug exposure.