The predictor role of FEV1 in airway management of patients under laryngeal tumor surgery.

Background and objective: Because of fixed airway obstruction in patients with laryngeal tumors, measurement of FEV1 can help in predicting the degree of airway obstruction and deciding the safe plan for anesthesia. Materials and methods: 154 patients, 40-80 years old, with ASA class II-III who were scheduled for elective surgery enrolled in this study. Pulmonary function tests (PFT) was done before surgery for all patients. They were divided into three groups based on the result of PFT: Group 1: FEV1 > 2.5 L which received standard anesthesia induction. Group 2: FEV1=1.5-2.5 L, induction was performed by keeping spontaneous breathing and Group 3: FEV1 < 1.5 L: which awake intubation was performed with topical anesthesia. Results: there was significant difference in intubation time and attempts among 3 groups (8.91.8, 10.7±1.7, 15.6±6.3 sec.p=.000; 1.2±0.5, 1.4± 0.6, 1.7±0.8, p=.002 respectively). Failed intubations were 3, 4, 9 in three groups respectively, which was not statistically different (P=0.1). Conclusion: Due to fixed airway obstruction in patients with laryngeal tumors, FEV1 can be used as a predictor for classification and choosing a safe method for induction of anesthesia