Pressure ventilation vs. volume ventilation and its impact on the level of CO 2 expired in surgery laparoscopic Ventilaci¢n por presi¢n vs ventilaci¢n por volumen y su impacto en el nivel de CO 2 expirado en una cirug¡a laparosc¢pica
The anesthetic management has been fi tted to the needs of the laparoscopic surgery, as a way to keep the blood CO 2 levels in between the physiologic needs. The equilibrium between the production and elimination of this gas, seems to be affected by the introduction of a large amount of CO 2 in the abdominal cavity, gas normally used in this surgery to insufl ate and start a pneumoperitoneum. The purpose of this study is to know the adequate parameters in the pressure controlled ventilation in laparoscopic surgery and make a comparison against the volume controlled ventilation to determine in wich of the 2 modes establish a diminutive end tidal CO 2. The sample size was 92 patients between 18 and 80 years old with an ASA I-II classifi cation, who didn't present cardiopulmonary illness and were programmed for laparoscopic cholecystectomy. The total of the patients were randomly divided into 2 groups of 46 patients each, they all were managed by general anesthesia and every group was assigned with a ventilation mode. The measured parameters at the beginning, during, and at the end of the pneumoperitoneum were oxygen saturation, cardiac frequency, blood pressure, tidal volume, minute volume, air way pressures, end tidal CO 2, and intraabdominal pressure. The statistical analysis was realized by panel data with random effects, analyzed by the program STATA 11. There were found signifi cant differences in the levels of end tidal CO 2,being lower in the pressure controled ventilation group, and even more markedly in female patients.