Observational study of Mallampati changes after prone spinal surgery

Abstract

Study ObjectiveTo evaluate airway changes in patients undergoing surgery in the prone position. DesignSingle-arm observational study. PatientsPatients between 18 to 65years old, scheduled for prone spinal surgery; 74 patients were enrolled and 54 patients were analyzed. InterventionThe initial airway examination was graded according to the Samsoon and Young modification of the Mallampati classification (MMP). Airway photographs were obtained in a standardized manner and were repeated 20minutes after extubation. The photographs were then randomized. MeasurementsSubjects’ age, gender, race, weight, duration of surgery, amount of crystalloid fluid given, and estimated blood loss were recorded. Three senior anesthesiologists who were blinded to the origin of the photographs analyzed and graded the airways. Main ResultsAll statistical tests showed significance between preMMP and postMMP scores (P<0.001). There was no difference between pre and post interobserver MMP scores. The MMPs of 12 patients (22%) did not change and MMP scores were changed in 42 patients (78%): 30 (71%) patients by one class, 10 (24%) patients by two classes, and two patients (5%) by three classes. There was no correlation between patients whose MMP was changed and length of surgery or crystalloid administered. ConclusionModified Mallampati scores increased in the majority of patients after spinal surgery in the prone position.