Abstract
BACKGROUND: Oral cavity and oropharyngeal cancer impose significant threat to airway management. Head and neck radiotherapy (HNRT) may further increase the difficulty of tracheal intubation. We hypothesized that a history of HNRT would be associated with a high rate of difficult tracheal intubation. METHODS: Adult patients with a history of HNRT were identified. Non-HNRT controls were case-matched by age, sex and body mass index. The tracheal intubation status between the two patient groups (treated vs. untreated with HNRT) was compared. The t test was used to evaluate differences in continuous variables between the 2 groups. Fisher's exact test or a chi-square test was used to test for associations between radiation status and patient characteristics that may be associated with difficult tracheal intubation. Odds ratio and its confidence interval were used to assess the effect of radiation status on intubation status. RESULTS: The final cohort of 472 matched patients in age, sex and body mass index consisted of 236 patients who had HNRT before surgery and 236 who had upfront surgery without HNRT. The percentage of patients who had restricted neck range of motion in the HNRT group was significantly higher than in the control group (22.3% vs. 11.0%; p = 0.001). The proportion of patients with trismus (p = 0.11) or difficult tracheal intubation (p = 0.73) did not differ significantly between the 2 groups. 12.7% patients in the study had difficult tracheal intubation. Patients who had mallampati scores of 3 or 4 had significantly higher rate of difficult tracheal intubation than did patients with mallampati scores of 1 or 2 (17.8% vs. 8.7%; p = 0.004). Multivariate logistic regression model showed no difference between HNRT and intubation status after adjusting neck range of motion and mallampati score (OR = 0.91, 95% CI: 0.510 to1.612). CONCLUSIONS: Previous treatment with HNRT was not associated with additional risk of difficult tracheal intubation. Mallampati score may be a sensitive measurement for difficult tracheal intubation in this patient population.