Difficult direct laryngoscopy in patients with cervical spine disease

TLDR

The study evaluated 253 pre‑operative cervical spine patients, grading glottic visibility at direct laryngoscopy with the Cormack‑Lehane scale. Difficulty (Cormack‑Lehane grades 3–4) occurred in 20 % of patients, was more common in occipito‑atlanto‑axial disease, and was best predicted by reduced C1‑C2 posterior element separation on lateral radiographs and high Mallampati scores, with class A protrusion associated with rare difficulty and class C with inevitable difficulty.

Abstract

Summary Two hundred and fifty three patients were examined before surgery for cervical spine disease. The grade of glottic visibility was determined at direct laryngoscopy, using the classification proposed by Cormack and Lehane. The overall prevalence of difficulty (grades 3 and 4) was 20%. Patients with disease that includes the occipito‐atlanto‐axial complex have a higher prevalence of difficulty than those with disease below the axis vertebra. Occipito‐atlanto‐axial disease is associated with poor mandibular protrusion. The best single predictor of difficulty was reduced separation of the posterior elements of the first and second cervical vertebrae on lateral radiographs. The Mallampati examination was the best single predictor on physical examination. The Mallampati may be an indicator of poor cranio‐cervical extension. Difficulty was rare in patients with class A mandibular protrusion, and invariable in patients with class C protrusion.