Predictors of difficult intubation in patients with cervical spine limitations

Cervical spine function is of paramount importance to the management of the airway. What has not been reported in the literature is a systematic analysis of airway management in patients with cervical spine limitation (CSL) compared with their normal counterparts or a predictive model of difficult intubation (DI) in patients with CSL.

We reviewed the electronic charts of 14,053 patients and identified those with CSL based on the preoperative airway evaluation. We then compared various airway parameters in patients with CSL to those without CSL and further assessed risk factors for DI in patients with CSL. We develop a predictive model on the basis of multivariate analysis of such risk factors.

Of the cohort studied, 1145 or 8.1% of patients were documented as having some form of CSL, with an average age of 60. In the <60 population, CSL was associated with a statistically significant increase in difficult and impossible mask ventilation, difficult laryngoscopy, and DI. In the population > or =60 years old, CSL was associated with a statistically significant increase in difficult laryngoscopy and DI. There were no significant differences in mask ventilation between normal and CSL patients in the population > or =60. Multivariate modeling revealed age > or =48, Mallampati 3 or 4, and thyromental distance <6 cm as independent preoperative risk factors of DI in patients with CSL. A predictive model is developed on the basis of these findings.

Limitations of cervical spine mobility are relatively common and increase the incidence of difficulty throughout the spectrum of airway management. DI should be anticipated in CSL patients who are > or =48 years old, have a Mallampati class 3 or 4, and a thyromental distance of <6 cm.