Airway scope and StyletScope for tracheal intubation in a simulated difficult airway.

Background: Direct laryngoscopy is difficult when the cervical spine is immobilized. The Airway Scope and StyletScope are new laryngoscopes designed to facilitate intubation under these circumstances. Thus, in patients wearing a rigid cervical collar to simulate a difficult airway, we tested the hypothesis that the intubation success rates of the Airway Scope and StyletScope are similar, but that intubation with Airway Scope is faster.

Methods: Adult patients requiring tracheal intubation as part of anesthesia were enrolled. After anesthesia induction and muscle relaxation, patients' necks were stabilized with a rigid Philadelphia collar and patients were randomly assigned to tracheal intubation with Airway Scope (n = 50) or StyletScope (n = 50). Overall intubation success rate, time required for intubation, the number of attempts required for successful intubation, and airway complications related to intubation were recorded.

Results: Overall intubation success rates were 98% with Airway Scope and 96% with StyletScope. Intubation was 19 s faster with Airway Scope (32[8] s; mean) versus StyletScope (51[29] s). The number of required intubation attempts was similar with each device: 26/18/5 (first/second/third attempt) for Airway Scope versus 26/17/5 for StyletScope. The incidence of mucosal trauma and lip injury was similar, except esophageal intubation occurred only with StyletScope (n = 6); neither dental injury nor hypoxia occurred.

Conclusions: Both the Airway Scope and StyletScope offer high success rates in a simulated difficult airway achieved by a rigid collar. However, the Airway Scope is faster and less likely to cause esophageal intubation.