The Predictive Value of Videoryngoscopy in Preoperative Airway Evaluation in Obese Patients

Overview

The aim of this study is the evaluation of preoperativevideolaryngoscopy, as a possible predictor of difficult laryngoscopy and intubation during elective general anesthesia in an obese population. Videolaryngoscopy is a minimally invasive examination performed during difficult intubation evaluation but not used routinely . On the other hand, current strategies used to predict the ease of intubation are still not sufficiently sensitive and specific. An unexpected difficult or failed intubation at the induction of general anesthesia is a seriuos, and potentially fatal, emergency in anesthesia. In literature, a correlation between anatomical and functional parameters highlighted by videolaryngoscopy and difficulty of laryngoscopy and intubation has never been demonstrated nor indagated. There is only some case reports related evaluation of diffucult airway by videolaryngoscopy . If proven, this might give the Anesthestiologist further information about the expected difficulty of laryngoscopy and intubation, guiding a different anesthesiological strategy.

This is a prospective, single-center, observational study. Aim of this study is the evaluation of preoperative videolaryngoscopy as a predictor of difficult laryngoscopy and intubation during elective general anesthesia in an obese population. Unexpected difficult of failed intubation is a serious, and potentially fatal, occurrence at the induction of general anesthesia. However, current strategies used to predict the ease of intubation are still not sufficiently sensitive and specific. Routine airway evaluation will be performed by the same anesthesiologist for patients with a BMI above 30 who will undergo general anesthesia for scheduled surgery. In the preoperative operating room, these patients will undergo videoingoscopy and a POGO score will be applied (10% lidocaine will be sprayed on tonsil sites). The investigators who do not performed preoperative videolaryngoscopy evaluation will be also collected data about the preoperative evaluation made by the Anesthesiologist as well as the effective difficulty of laryngoscopy and intubation encountered at the induction of general anaesthesia, expressed by the Cormack - Lehane scale and the Intubation Difficulty Scale (IDS) as described in literature. General anesthesia will be performed as usual and will not be influenced by videolaryngoscopic evaluation as the Anesthesiologist will be blind to it, and he/she will be free to choose the best anesthesiological plan for his/her patient; whether an elective awake intubation will be chosen, this will exclude the patient from the study. For safety reasons, the only exception to blindness is an expected difficulty of intubation (POGO score 0%) by senior anesthesiologist, based upon the physician's experience. In this case, he will talk to the Anesthesiologist about and the patient will be excluded from the study. Preoperative data obtained by videolaryngoscopy and intraoperative data recorded by the Anesthesiologist will be matched and analyzed, to explore a possibile relationship.