Segmental cervical spine movement with the intubating laryngeal mask during manual in-line stabilization in patients with cervical pathology undergoing cervical spine surgery

We quantified the extent and distribution of segmental cervical movement pr oduced by the intubating laryngeal mask (ILM) during manual in-line stabili zation in 20 anesthetized patients with cervical pathology undergoing cervi cal spine surgery. All patients had neurological symptoms preoperatively. T he ILM was inserted with the head and neck in the neutral position. Intubat ion was facilitated by transillumination of the neck with a lightwand. Cerv ical movement was recorded with single-frame lateral radiographic images ta ken 1) immediately before induction (baseline); 2) during ILM insertion (in sertion); 3) when transillumination was first seen at the cricothyroid memb rane (intubation A); 4) when the tube was being advanced into the trachea ( intubation B); and 5) during ILM removal (removal). Radiographic images wer e digitized and the degree of flexion/extension and posterior movement meas ured for the occiput (CO) through to C5. During ILM insertion, C0-5 were fl exed by an average of 1-1.6 degrees (all P < 0.05). During intubation A/B, CO-4 were flexed by an average of 1.4-3.0 degrees (all P < 0.01), but C5 wa s unchanged. During ILM removal, C0-3 were flexed by an average of 1 degree (all: P < 0.05), but C3-5 were unchanged. During insertion and intubation A/B, C2-5 were displaced posteriorly by an average of 0.5-1.0 mm (all: P < 0.05). During removal, there was no change at C1-5. Neurological symptoms I mproved in all patients. We conclude that the ILM produces segmental moveme nt of the cervical spine despite manual in-line stabilization in patients w ith cervical spine pathology undergoing cervical spine surgery. This motion is in the opposite direction to direct laryngoscopy, suggesting that diffe rent approaches to airway management may be more appropriate depending on t he nature of the cervical instability.