Abstract
Background: The obstetric airway is a significant cause of maternal morbidity and mortality. Endotracheal intubation is considered the standard of care but the laryngeal mask airway (LMA) has gained acceptance as a rescue airway and has been incorporated into the obstetric airway management guidelines. In this randomized controlled trial, we compared the Supreme LMA (SLMA) with endotracheal intubation (ETT) in managing the obstetric airway during Caesarean section.
Methods: Parturients who underwent elective Caesarean section under general anesthesia were randomized to receive either an SLMA or ETT as their airway device. Our primary outcome was first-attempt insertion success. Successful insertion was defined as adequate bilateral air entry with auscultation and the presence of end-tidal carbon dioxide on the capnogram. The first-attempt insertion success rate was compared using the Chi-Square test. Secondary outcomes included time-to-ventilation, seal pressure, ventilation/hemodynamic parameters, occurrence of clinical aspiration, fetal outcomes, and maternal side effects associated with the airway device.
Results: We recruited 920 parturients (460 SLMA, 460 ETT) who underwent elective Caesarean section under general anesthesia. Patient characteristics were similar between the groups. First attempt success was similar (Risk Ratio--RRETT/SLMA: 1.00 (95%CI: 0.25, 4.02), p= 1.00). SLMA was associated with reduced time to effective ventilation (Mean Difference-- MD -22.96; 95%CI: -23.71, -22.21 seconds) compared to ETT group (p<0.0001). Ventilation parameters, maternal and fetal outcomes were similar between the groups, and there was no aspiration.
Conclusions: SLMA could be an alternative airway management technique for a carefully selected low risk obstetric population, with similar insertion success rates, reduced time to ventilation and less hemodynamic changes compared with ETT. Our findings are consistent with the airway guidelines in recommending the second line use of LMA in the management of obstetric airway.
Ethics Approval: This study was approved by the Institutional Review Board (approval obtained on 25th October 2012) at the Quanzhou Women’s and Children’s Hospital, Fujian Province, China (clinical trials registration number: NCT01858467).
Keywords: Laryngeal Mask Airway, Obstetric, Cesarean Section, General Anesthesia.