Correlation between voice parameters and number of intubations attempts: a prospective study

Abstract

Purpose: Predicting difficult airway management remains challenging so far. All predictors available to the present moment feature just a poor performance to anticipate problems over the airway manipulation. In this field, voice parameters have been proved to be associated with upper airway anatomy besides being deemed to predict difficult airway management. These conceptions led us to investigate the correlation between the formant frequencies (Figure 1) and the number of intubations attempts. Methods: We performed a prospective study involving 453 patients who underwent elective surgeries under general anaesthesia with tracheal intubation. Before transporting the patients to the operating room, we collected their data on sex, age, weight, height, ASA physical status, Body Mass Index (BMI), and acoustic parameters from five phonemes (/a/, /e/, /i/, /o/, /u/). In the operating room, during the airway management maneuvers, the number of attempts to successfully allocate the orotracheal tube was noted. The Spearman correlation test was performed among the quantitative variables. Results: The number of intubation attempts were correlated to the formants ef2 (r=-0.123, p=0.016); of2 (r=0.097, p=0.037); and of4 (r=0.114, p=0.014). Age, weight, height, and BMI did not show any correlation to the number of intubations attempts. Conclusions: Voice formants were correlated to the number of intubations attempts and may constitute an alternative tool for preoperative upper airway assessment.