A Maternal Airway Database: Lessions Learned
Abstract Number: S-37
Abstract Type: Original Research
Introduction: The best approach for managing the failed epidural for c-section is a topic frequently discussed at SOAP. The recent NAP4 study included 2 of 4 failed intubations that occurred following unsuccessful epidural anesthesia. Is sedated fiberoptic a reasonable mandate following a failed regional block or should a rapid sequence induction be performed with a LMA available for rescue?
Methods: We reviewed our maternal airway database from 1974- 2011 to determine how the introduction of newer technology: fiberoptics, LMA, and Glidescope has impacted airway management over the past 30yrs. A meta-analysis of difficult airway predictors (Mallampati, thyromental, interincisor) was conducted to determine the area under the composite receiver –operator curve(aucROC).
Results: The incidence of failed rigid laryngoscopy(FRL) from 1974-1985 was 1/264. The incidence of FRL in our obstetric unit for the years 1985-2004 was 1/833 with a prophylactic sedated fiberoptic rate(PSFO) of 14%. The FRL for the years 2005-2010 was 1/50 with a PFSO of under 5%. The LMA was used as a rescue device in 5/10 cases. Since the introduction of the Glidescope in 2010, no failed rigid laryngoscopies occurred.
Discussion: Failed regional anesthesia accounts for 20% of the general anesthesia cases in our database. To prevent 50% of FRL would require a PSFO of 15% (figure), unachievable in most obstetrical units where a designated fiberoptic is not readily available. With over 50 reported airway rescues attributed to the LMA in the literature, a practical approach is to use a Glidescope for a rapid sequence induction with a LMA in reserve.
References: Cook, BJA 106 (5): 617–31 (2011) Bullough,IJOA( 18): 342-45(2009)