Background: Preoperative airway assessment plays a key role in the context of difficult airway management. Several scores have been proposed to predict difficult intubation including the el-Ganzouri index (EL.GA). Anatomical parameters such as the opening of the mouth or the circumference of the neck (which currently is not usually evaluated) are used to predict difficult intubation. The nutritional status of super-morbid obesity (body mass index [BMI] > 50 kg m-2) is a recognised risk factor for difficult intubation.
Methods: This is a single-centre, retrospective, observational study whose aim is to validate an additional parameter (anatomical plus nutritional) to the El.GA index, hence the choice of the acronym for the definition of the study: EL.GA+, in predictivity of airway management; multiple logistic regression analysis was performed to determine the predictive role of BMI, neck circumference and opening of the mouth of intubation difficulty measured with the gold standard.
Results: In total, 240 patients who had an elective surgical procedure under general anaesthesia, requiring endotracheal intubation, were examined. The predictive value of the EL.GA score was confirmed by the values of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) according to the data reported in the literature. Furthermore, based on the values of the PPV and NPV (0.69 and 0.60 respectively), neck circumference of 42.5 cm can be taken as a cut-off value for which EL.GA+ becomes predictive of difficult intubation in patients with mild obesity (BMI of 30 to 35).
Conclusions: The EL.GA+ score greatly increases the prediction of difficult laryngoscopy in mildly obese patients.
Keywords: decision support techniques; difficult airways; el-Ganzouri index; intratracheal intubation; airway management.