Blind Orotracheal Intubation with the Intubating Laryngeal Mask versus Fibreoptic Guided Orotracheal Intubation with the Ovassapian Airway. A Pilot Study of Awake Patients

Abstract

In a randomized, prospective pilot study, we compared awake blind orotracheal intubation using the intubating laryngeal mask airway (blind-ILM) with awake fibreoptic-guided orotracheal intubation using an Ovassapian airway (FOS-OA). Fifty-four patients (ASA 1 to 3, aged 18 to 85 years) requiring awake intubation for elective surgery were randomly allocated by coin toss into two groups: 31 patients were intubated blindly through the ILM (blind-ILM) and 23 were intubated using fibreoptic guidance through the Ovassapian airway (FOS-OA). Sedation to a target clinical end-point (spontaneous eye-closing, but responsive to verbal command) was obtained with fentanyl/midazolam and a cricothyroid puncture was performed with 3 ml lignocaine 4%. The oropharynx was then topicalized until tolerance of a Guedel airway was achieved. The number of failed attempts (maximum of three allowed), overall success rates, the time from insertion of the airway to capnographic (blind-ILM) or fibreoptic (FOS-OA) confirmation of intubation or until three failed attempts, and cardiovascular responses before and during intubation, were recorded. The first time (blind-ILM, 25/31 [81%]; FOS-OA, 20/23 [87%], P=0.6) and overall (blind-ILM, 26/31 [84%]; FOS-OA, 22/23 [96%], P=0.2) intubation success rates were similar. The mean±SD time to intubation was shorter for the blind-ILM group (104±65 vs 158±115 sec, P=0.05). There were no clinically significant differences in blood pressure or heart rate between groups. Compared with baseline values, there was no cardiovascular response to intubation in either group. We conclude that the blind-ILM and FOS-OA techniques have similar success rates and cardiovascular responses, but intubation is slightly quicker with the blind-ILM technique.