Interobserver variability for non-invasive prediction of difficult intubation in different years of anesthesiology residency.

Background: The incidence of a difficult laryngoscopy/intubation, which could lead to failed intubation is in the range of 1.5%-13%. Failed intubation may lead to hypoxia, brain damage or death. Preoperative evaluation of the airway can be accomplished by non-invasive bedside clinical tests during physical examination. We studied interobserver variability for non-invasive prediction of difficult intubation in different anesthesiology residency years.

Methods: Three hundred eighty four adult patients undergoing elective surgery with general anesthesia and endotracheal intubation were enrolled this study. The investigators were divided in to two groups: three of them were in 4th (Group 1) and the other three were in 1st (Group 2) year of their anesthesiology residency. The variables evaluated were age, weight, height, submental-cervical angle, measurements of mandibular space, deviation of trachea, jaw-hyomental distance, swelling or scar tissue at neck, limited mouth opening, small mouth cavity, macroglossia, cleft lip-palate, long teeth and modified Mallampati score.

Results: The incidence of difficult intubation is 4.9%. Group 1 is more successful than Group 2 in predicting difficult intubation.

Conclusions: Regarding Mallampati score, measurements of mandibular space, jaw-hyomental distance, mouth opening and mouth cavity; interobserver variability is detected in predicting difficult intubation among different years of anesthesiology residency. In means of submental-cervical angle, tracheal deviation, swelling or scar tissue at neck and macroglossia, similar results which are statistically significant, are obtained.