Manual In-Line Stabilization for Acute Airway Management of Suspected Cervical Spine Injury: Historical Review and Current Questions
Direct laryngoscopy with manual in-line stabilization is standard of care for acute trauma patients with suspected cervical spine injury. Ethical and methodologic constraints preclude controlled trials of manual in-line stabilization, and recent work questions its effectiveness. We searched MEDLINE, Index Medicus, Web of Knowledge, the Cochrane Database, and article reference lists. According to this search, we present an ancestral review tracing the origins of manual in-line stabilization and an analysis of subsequent studies evaluating the risks and benefits of the procedure. All manual in-line stabilization data came from trials of uninjured patients, cadaveric models, and case series. The procedure was adopted because of reasonable inference from the benefits of stabilization during general care of spine-injured patients, weak empirical data, and expert opinion. More recent data indicate that direct laryngoscopy and intubation are unlikely to cause clinically significant movement and that manual in-line stabilization may not immobilize injured segments. In addition, manual in-line stabilization degrades laryngoscopic view, which may cause hypoxia and worsen outcomes in traumatic brain injury. Patients intubated in the emergency department with suspected cervical spine injury often have traumatic brain injury, but the incidence of unstable cervical lesions in this group is low. The limited available evidence suggests that allowing some flexion or extension of the head is unlikely to cause secondary injury and may facilitate prompt intubation in difficult cases. Despite the presumed safety and efficacy of direct laryngoscopy with manual in-line stabilization, alternative techniques that do not require direct visualization warrant investigation. Promising techniques include intubation through supraglottic airways, along with video laryngoscopes, optical stylets, and other imaging devices.