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October 14, 2007
2:00 PM - 4:00 PM
Room Hall D, Area P,
A Comparison of the AuraOnce™ and LMA-Unique™ as an Intubation Conduit in Elective Surgery
Carin A. Hagberg, M.D., Nicholas Lam, M.D., Melissa Chan, M.D., John Craig, M.D., Dawn Iannucci, M.S.-1
Department of Anesthesiology, The University of Texas Medical School at Houston, Houston, Texas
Background: The Laryngeal Mask Airway (LMA) is a supraglottic airway device first introduced into clinical practice in the 1980's.1 Since the 1996 revision of the 1993 ASA Practice Guidelines for the Management of Difficult Airway to include the LMA as a rescue device, there is an increasing need to exchange the LMA for an endotracheal tube (ETT) after failed direct laryngoscopy (DL).2 One technique of exchange is using the Aintree Intubation Catheter® (AIC; Cook Critical Care, Bloomington, IN) in combination with a fiberoptic bronchoscope (FOB). This study compares the LMA-Unique™ (LMA; North America, San Diego, CA) and the AuraOnce™ (AO; A/S, Denmark) as intubation conduits using a fiberoptic-guided AIC.

Methods: Following approval by the Institutional Review Board and written informed consent, 148 ASA I-III and Mallampati I-III patients undergoing elective surgery under general anesthesia were enrolled. Anesthesia was induced with intravenous propofol (2mg/kg) and fentanyl (1-2ug/kg). After verbal instruction, resident anesthesiologists performed all airway procedures. Following successful insertion of the LMA (AuraOnce™ n=74; LMA-Unique™ n=74), intracuff pressure was adjusted to 60 cmH20, and a leak test performed. Using a FOB, the AIC was guided through the LMA and positioned above the carina. The FOB then was removed from the AIC, followed by removal of the LMA, leaving the AIC in place. An ETT was guided over the AIC using DL to ensure proper placement. Time to insert the LMA (entering oropharynx until 1st capnograph breath), AIC (FOB enters LMA to placement above carina), and ETT (laryngoscope enters oropharynx until 1st capnograph breath) were recorded. Ease of exchange (# of attempts), leak pressure, intraoperative complications (laryngospasm, blood, coughing, etc.), and airway morbidities at 2 and 24 hrs postoperatively (sore throat, hoarseness, odynophagia, etc.) were also documented.

Results: Patient demographics were comparable between the 2 groups regarding age, sex and BMI. Both the AO and LMA performed similarly with respect to adequate ventilation, leak pressure (AO 22.6 cmH2O ± 5.53, LMA , 20.3 cmH2O ± 5.66 ) ease and time to place the device (AO 23.9 sec ± 12.41, LMA 26.3 sec ± 12.94) FOB-AIC insertion (AO 49.1 sec ± 46.40, LMA 42.8 sec ± 31.57), and AIC-ETT exchange (AO 31.6 sec ± 18.93, LMA 33.2 sec ± 15.41). There were no placement failures and all airways were secured by an ETT < 3 attempts. Intraoperative and postoperative complications were similar with the exception of a significant difference (p < 0.05) in the incidences of sore throat at 24 hours (AO 31, LMA 18) and odynophagia at 24 hours (AO 24, LMA 10).

Discussion: Using FOB-guided AIC, AO is comparable to the LMA as an intubation conduit in securing effective airway in mechanically ventilated anesthetized adults. This technique is both safe and easy to perform. Proper insertion technique should be utilized to minimize complications.


1. 1. Brain AIJ: The laryngeal mask: a new concept in airway management. Br J Anaesth 1983;55:801-5

2. Practice Guideline for Management of Difficult Airway; ASA 2003.

Anesthesiology 2007; 107: A944