Prognostic factors of intraoperative accidental extubation during laryngeal surgeries

Head and neck surgery is considered high-risk for difficult intubation and accidental extubation. Laryngomicroscopy implies surgical manipulations at the level of the vocal cords. Also, this type of surgery demands a particular position for the patient during the whole surgical intervention. All of this makes accidental extubation even more possible.

We included a total of 100 patients scheduled for laryngomicroscopy in the study. We have assessed patients' general and clinical data and provided necessary measurements. After the intubation, we documented the depth of the endotracheal tube at the level of the upper incisors and repeated the measurement after the surgical intervention. We recorded all possible difficulties encountered by the surgeon.

We found a significantly more frequent tube dislocation in patients from the difficult intubation group, with χ² =6.632, p =0.010. Inter-incisor gap (IIG) and modified Mallampati score showed statistical significance regarding tube dislocation, with p values of 0.002 and 0.047, respectively. There was statistical significance between tube dislocation and difficulties experienced by surgeons, with χ² =13.504 and p =0.001. According to the area under the curve (AUC) at the Receiver operating characteristic (ROC) curve, the cut-off value for significant tube dislocation was 1.15 cm. When we divided the enrolled patients into two groups, below and above the cut-off value, the IIG maintained statistical significance with a cut-off value of 5.25 cm.

Modified Mallampati score and IIG are considered valuable parameters for rapid preoperative risk assessment of possible accidental extubation. The final depth of the endotracheal tube should be about two cm deeper than necessary, as long as there is adequate ventilation on both sides of the lungs. Difficult intubation undoubtedly represents a risk for accidental extubation occurrence. HIPPOKRATIA 2023, 27 (4):141-147.