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

Abstract

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. 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. 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. 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.