Join now to get access to this content and more.
Become a SOAP member and have access to our benefits.
- For Review: SOAP Consensus Statement on Neuraxial Procedures in Thrombocytopenic Parturients
- Sample Centers of Excellence Applications
- ASA Corner
- SOAP Policy and Procedure Manual (P&P Manual)
- SOAP Expert Opinions
- SOAP's Learning Modules
- 2019 Annual Meeting Lecture Videos
- December 2018 - SOAP Unofficial Guide to ASA Committees Webinar
- Submit a Position
- View Job Postings
- Previous Meeting Archives
- Previous Meeting Abstract Search
- CMS Guidelines
- Member Benefits
- Newsletter Clinical Articles
- ACOG Documents
- Search our Patient Safety Archive
- Ask SOAP a Question
- Global Health Opportunities
- And more…
Analysis of Dose Response of intravenous Anesthetic for Fetal procedures
Abstract Number: GM 5
Abstract Type: Original Research
Pre-natal procedures on fetuses are a relatively new phenomenon but with increasing successful outcomes they are increasing in demand in our institution. In one example of its utility is in the twin to twin transfusion syndrome which is known to have a perinatal loss ranging between 80-90%. During a fetal procedure, fetal immobility is of the utmost importance for success of the procedure and to avoid fetal injuries and complications. Even though remifentanil has been approved by the FDA for use during fetal procedures, there were only a handful of studies investigating its use in fetal procedures. One study showed that remifentanil is superior to local or regional anesthesia and another showed it was superior to diazepam. Both studies demonstrated that it produced excellent fetal immobility and maternal sedation safely. In Jackson Memorial Hospital it is the anesthetic of choice for fetal procedures and standard of care. Due to the scarcity of information in the literature, we have conducted a prospective clinical study to determine the minimum effective dose of Remifentanil required to achieve excellent fetal immobility during a fetal procedure using the Dixon and Massey up down sequential allocation method. A high resolution ultrasonographic examination of the gravid uterus was done to assess fetal activity prior to initiating the remifentanil infusions.
Forty eight pregnant females 18 yrs or older with no history of cardiac, renal or hepatic diseases scheduled to undergo a fetal procedure, were enrolled. Average age of our study population was 29 years, ranging from 47-20 years. Almost half (49%) of our patients were between 89-70 kg and 15% were more than 90kg. More than three quarters of the cases (77.8%); fetuses were noted to be active and only 22.2% had sluggish or low activity. Fetal movements were still present in 20 of 47 (43%) of the patients after the first 10 minutes, indicating a 57.4% (27/47) effective rate for the initial dose. Our study showed a mean effective remifentanil infusion of 0.097mcg/kg/min. The most rapid infusion required was 0.150mcg/kg/min and the least was 0.025mcg/kg/min. The resulting minimum effective remifentanil dose using the Dixon and Massey method was 0.085mcg/kg/min (95% CI 0.0599, 0.1095)
Studies have shown that fetoscopic surgeries performed successfully under local or regional anesthesia, did not result in excellent maternal sedation or fetal immobilization. Our study showed that we were able to achieve optimal surgical conditions by providing excellent fetal immobility and maternal sedation without a single case of fetal injury or maternal respiratory depression, with a minimum effective remifentanil dose of 0.085mcg/kg/min.