A model to predict difficult airway alerts after videolaryngoscopy in adults with anticipated difficult airways – the VIDIAC score

Abstract

A model to classify the difficulty of videolaryngoscopic tracheal intubation has yet to be established. The videolaryngoscopic intubation and difficult airway classification (VIDIAC) study aimed to develop one based on variables associated with difficult videolaryngoscopic tracheal intubation. We studied 374 videolaryngoscopic tracheal intubations in 320 adults scheduled for ear, nose and throat or oral and maxillofacial surgery, for whom airway management was expected to be difficult. The primary outcome was whether an anaesthetist issued a `difficult airway alert´after videolaryngoscopy. An alert was issued after 183 (49%) intubations. Random forest and lasso regression analysis selected six intubation-related variables associated with issuing an alert: impaired epiglottic movement; increased lifting force; direct epiglottic lifting; vocal cords clearly visible; vocal cords not visible; and enlarged arytenoids. Internal validation was performed by a 10-fold cross-validation, repeated 20 times. The mean (SD or 95%CI) area under the receiver operating characteristic curve was 0.92 (0.05) for the cross validated coefficient model and 0.92 (0.89-0.95) for a simplified unitary score (VIDIAC score with component values of À1 or 1 only). The calibration belt for the coefficient model was consistent with observed alert probabilities, from 0% to 100%, while the unitary VIDIAC score overestimated probabilities < 20% and underestimated probabilities > 70%. Discrimination of the VIDIAC score for patients more or less likely to be issued an alert was better than discrimination by the Cormack-Lehane classification, with mean (95%CI) areas under the receiver operating characteristic curve of 0.92 (0.89-0.95) vs. 0.75 (0.70-0.80), respectively, p < 0.001. Our model and score can be used to calculate the probabilities of difficult airway alerts after videolaryngoscopy.

Transnasal Videoendoscopy for Preoperative Airway Risk Stratification: Development and Validation of a Multivariable Risk Prediction Model

“…Patients with pharyngolaryngeal lesions are at high risk for difficult tracheal intubation [6][7][8][9][10] with an expected incidence up to 28%, 7 which is attributed to the size, location, bleeding tendency, risk of swelling, and impaired view during airway management. 6,7,28 Predictive tests, developed in cross-sectional surgical populations with a low average risk, are suspected to have poor discrimination in patients with laryngopharyngeal disease, as they are not tailored to these patients.…”

“…First, the sample size should ensure an accurate estimate of the overall outcome risk. Based on literature review and our own in-house data, 6 , 7 , 9 , 22 we assumed a primary end point prevalence of 0.15 in patients undergoing otorhinolaryngologic surgery and a margin of error ≤0.05. Second, the sample size should lead to a shrinkage of predictor effects of 10%.…”

“…Current guidelines recommend that airway evaluation may include preoperative bedside endoscopy. 5 However, although patients with pharyngolaryngeal lesions are at high risk for difficult airway management, [6][7][8][9][10] the diagnostic value of these pathological TVE findings for predicting risk associated with airway management is still unknown. An evidencebased score, assessment tool, or structured workflow is lacking.…”

A universal classification for videolaryngoscopy using the VIDIAC score requires real world conditions: a reply

“…It is well known that airway operator skill and experience affect performance of tracheal intubation [2]; therefore, skilled senior airway operators are often favoured participants in interventional studies. However, this should not be confused with the videolaryngoscopic intubation and difficult airway classification (VIDIAC) study [3], which is a prospective observational multivariable prediction model development and validation study.…”

Investigation of tracheal intubation operator and patients in difficult airway study

“…We read with great interest the study by Kohse et al. [1], who have developed a scoring system: the videolaryngoscopic intubation and difficult airway classification (VIDIAC) score and concluded that this model will be of significant help to anaesthetists in terms of airway management when planning follow‐up anaesthesia. However, we would like to raise some questions regarding the study.…”