Obesity and the Other Independent Predictors in Elective Endotracheal Tube Intubations: A Narrative Review

Obesity is one of the challenging elements in health care. Studies have shown that as the body mass index (BMI) increases, the risk of chronic conditions tends to increase due to altered physiologic and metabolic demands. In addition to underlying physiological changes, anatomical changes can lead to common procedural challenges, such as difficult intravenous (IV) cannulation, difficult airway, and difficult intubation, which makes their preoperative and postoperative care challenging for the anesthesiologists. According to previous studies, there is no single best predictor for difficult airway or intubations and no designed protocol for choosing an intubation technique in obese patients. Some of the preoperative risk factors and techniques such as the modified Mallampati class, sternomental distance, thyromental distance, neck circumference, indirect mirror laryngoscopy, BMI, and intraoperative risk factors such as inappropriate positioning of the patient, suboptimal medication dosing, inappropriate laryngoscopy device acted as independent predictors for difficult airway and difficult intubation. Analyzing each element's importance and making suitable decisions for the individual will reduce the complications and prepare for unplanned emergencies in the operating room. This review is convincing with previous studies that obesity itself is not an independent predictor. Instead, as a preoperative risk factor, and till date, sternomental distance and the number of intubation attempts were demonstrated as significant independent predictors for adverse events. All the other independent factors and considerations were discussed, which can help with further research.