Changes in modified Mallampati class in patients undergoing percutaneous nephrolithotomy in prone position – A prospective observational study

Objective: Assessment and evaluation of changes in modified Mallampati class (MMC) in patients undergoing percutaneous nephrolithotomy (PCNL) in the prone position. Patients and Methods: Seventy-one patients undergoing PCNL in prone position who satisfied inclusion criteria were studied and their MMC was assessed preoperatively. The MMC was assessed immediately after surgery and 6 h, 12 h and 24 h postoperatively. The number of attempts for successful intubation, duration of surgery, the quantity of intraoperative fluids and irrigation fluids used, and blood loss was recorded to identify any significant correlation with changes in MMC. Results: MMC changed in 17 patients (23.9%) with the grade increasing by one in all the patients. Among the 17 patients who showed a change in MMC, 8 patients returned to baseline within 6 h, 6 patients at 12 h and the remaining 3 patients at 24 h. Conclusion: MMC worsened by one grade in almost one-quarter of the patients undergoing PCNL in the prone position. This change in MMC had no clinically significant correlation with the number of attempts for successful intubation, duration of surgery, quantity of intraoperative fluids and irrigation fluids used, and blood loss.