RESUMO
OBJECTIVES: The aim of this study was to investigate the effects of CO2 insufflation on the pressure of the middle ear cavity (PMEC) during laparoscopic surgery under total intravenous anesthesia (TIVA) with propofol or sevoflurane as an inhalational anesthetic maintenance. MATERIAL AND METHODS: Sixty patients who underwent laparoscopic/or non-laparoscopic surgery under general anesthesia were included in the study. For anesthetic maintenance with inhalation agents, 20 non-laparoscopic surgery patients in Group 1 were applied sevoflurane (2-2.5%). Forty patients who underwent laparoscopic surgery were randomized into two groups. Anesthesia was maintained with sevoflurane (2-2.5%) in twenty patients in Group 2 and the TIVA technique in 20 patients in Group 3. In Group 1, PMEC was measured before anesthesia, 10 and 30 min after endotracheal intubation, 10 min before extubation, and 15, 30, 60 min and 6 hours in the postoperative period. In Group 2 and 3, PMEC was measured before the anesthesia, 10 min after intubation, 10 and 30 min after CO2 insufflation, just before the CO2 elimination, 10 min before the extubation, and 15, 30, 60 min and 6 hours after extubation in the postoperative period. RESULTS: PMEC was significantly increased in Group 1 at 10 min after intubation, at 30 min of the operation, before extubation, and at postoperative 15 and 30 min (p < 0.05). In Group 3, differences between PMECs were detected at the 30th min of insufflation (p = 0.005), and during elimination (p = 0.035) compared to the initial measurement. Generally, the values remained positive in Group 1 and negative in Group 3. There was a significant difference between Group 1 and Group 3 at 10 min after the induction (p = 0.001). There was no statistically significant difference in PMECs between Group 2 and 3 patients undergoing laparoscopic surgery. CONCLUSIONS: Our results indicate that, in laparoscopic surgery, TIVA used for the maintenance of anesthesia did not increase the PMEC and the changes caused by sevoflurane were also in the normal range of middle ear pressures. In patients with previous ear surgery, if there is a need of classical surgical procedures in the future, sevoflurane anesthesia should not be the first choice due to its effects on PMEC, which cause it to be increased over 50 daPa, especially at 30 min after intubation. Patient characteristics including previous ear surgery should be considered in selecting the optimum anesthetic agents and technique.
