Preoperative pulmonary function evaluation for laparoscopic cholecystectomy.

Abstract

OBJECTIVE: Hypercarbia with respiratory acidosis is a recognized complication of laparoscopic cholecystectomy. This study was performed to identify preoperatively those patients who may develop hypercarbia and acidosis during the procedure. DESIGN: Retrospective analysis of preoperative variables. PATIENTS: Thirty-one consecutive patients underwent laparoscopic cholecystectomy at one institution who were receiving both preoperative pulmonary function tests and arterial blood gas analysis. RESULTS: More than 80 demographic, laboratory, and perioperative variables were entered into a univariate analysis to identify predictors of intraoperative acidosis (pH, < 7.35). Patient age, duration of the procedure, and preoperative blood gas values were not predictors of intraoperative acidosis. Several univariant predictors for patients experiencing carbon dioxide pneumoperitoneum-induced hypercarbia were identified; these included an elevated American Society of Anesthesiologists classification and significant decreases in forced expiratory flow at 25% of maximum, maximal forced expiratory flow, maximal voluntary ventilation, vital capacity, inspiratory capacity, and diffusing capacity of the lung for carbon monoxide. CONCLUSIONS: This study suggests that neither age nor preoperative arterial blood gas values are predictive of intraoperative hypercarbia and acidosis during periods of carbon dioxide pneumoperitoneum. However, preoperative pulmonary function measures of decreased flow, limited capacity, and compromised diffusion do correspond to the development of intraoperative acidosis. Preoperative evaluation with pulmonary function tests demonstrating forced expiratory volumes less than 70% of predicted values and diffusion defects less than 80% of predicted values can identify those patients who are at risk of developing hypercarbia and acidosis.