Valor predictivo de los test preoperatorios para estimar la intubación difícil en pacientes sometidos a la laringoscopia directa para la cirugía de oído, nariz y garganta

Background and objectives

Predictive value of preoperative tests in estimating difficult intubation may differ in the laryngeal pathologies. Patients who had undergone direct laryngoscopy were reviewed, and predictive value of preoperative tests in estimating difficult intubation was investigated.

Methods

Preoperative, and intraoperative anesthesia record forms, and computerized system of the hospital were screened.

Results

A total of 2.611 patients were assessed. In 7.4% of the patients, difficult intubations were detected. Difficult intubations were encountered in some of the patients with Mallampati scoring (MS) system class 4 (50%), Cormack–Lehane classification grade 4 (95.7%), previous knowledge of difficult airway (86.2%), restricted neck movements (cervical range of motion) (75.8%), short thyromental distance (81.6%), vocal cord mass (849.5%) as indicated in parentheses (P < .0001). MS had a low sensitivity, while restricted cervical range of motion, presence of a vocal cord mass, short thyromental distance, and MS each had a relatively higher positive predictive value. Incidence of difficult intubations increased 6.159 and 1.736-fold with each level of increase in Cormack–Lehane classification grade and MS class, respectively. When all tests were considered in combination difficult intubation could be classified accurately in 96.3% of the cases.

Conclusion

Test results predicting difficult intubations in cases with direct laryngoscopy had observedly overlapped with the results provided in the literature for the patient populations in general. Differences in some test results when compared with those of the general population might stem from the concomitant underlying laryngeal pathological conditions in patient populations with difficult intubation.