The temporary effect of short-term endotracheal intubation on vocal function

The objective of the study was to assess and perceive the vocal and pharyngeal symptoms and acoustic changes of voice after short-term endotracheal intubation and to evaluate the relation between these changes and the endotracheal tube parameters, number of intubation attempts, duration of anaesthesia, experience of anaesthesiologist. A total of 108 patients were evaluated preoperatively, 1–2 and 24 h after extubation. The vocal and pharyngeal symptoms, voice acoustic characteristics and maximum phonation time (MPT) were evaluated to find the relationship with endotracheal tube parameters, number of intubation attempts, duration of anaesthesia, experience of anaesthesiologist. All vocal and pharyngeal symptoms increased significantly at 24 h and remained significantly increased at 24 h after general anaesthesia. The vocal acoustic parameters changed significantly at 1–2 h: decrease of MPT and increase relative average perturbation were recorded. The day after the short-term intubation: only noise to harmony ratio and habitual pitch remains significantly changed. The most important endotracheal tube parameters that affect significantly (P value <0.05) the vocal function were the size of tube, cuff volume and number of intubation attempts. In relation to the anaesthesia, the changes of the acoustic parameters did not associate significantly with the anaesthesia-related parameters. No statistically significant relationship between experience of an anaesthesiologist and changes of the voice after anaesthesia was detected. Though being short-term, endotracheal anaesthesia is an invasive procedure, and its temporary influence on vocal function is important.