The effect of different end-tidal carbon dioxide levels on the end-tidal concentration of sevoflurane in patients undergoing laparoscopic cholecystectomy: randomized prospective trial

Background Carbon dioxide (CO 2 ) has anesthetic potency and effectively influences the circulatory system. There’s a relationship between end-tidal carbon dioxide (EtCO 2 ) levels and the anesthetic’s requirements during the surgical procedure. Aims We aimed to evaluate how varying EtCO 2 levels influence end-tidal sevoflurane (EtSevo) concentration in patients undergoing laparoscopic cholecystectomy. Patients and methods A total of 90 patients aged 30–65, both sexes, American Society of Anesthesiology class I-II, undergoing elective laparoscopic cholecystectomy were recruited for this randomized double-blinded prospective study. Patients were classified by computer-generated random sequence into three equal groups (L, N, and H). The measured EtSevo concentration at 30 min after pneumoperitoneum was the primary outcome. Results EtSevo at all recordings presented statistically significant variance ( P <0.05). The overall sevoflurane consumption in group L was significantly higher than in group N, and group H ( P <0.001). There was a statistically significant variance in the patients’ number who needed to increase sevoflurane and IV bolus fentanyl between the three studied groups ( P <0.05). The intracranial pressure and surgical field quality comparisons showed no statistically significant differences. ( P >0.05). Conclusions The high EtCO 2 levels (40–45 mmHg) could be valuable in patients undergoing laparoscopic cholecystectomy as it had better hemodynamic stability, lower-end-tidal and total consumption of sevoflurane with an effective anesthesia depth and nonclinical significant changes in ABG and no changes in intracranial pressure and surgical field quality assessments compared with the low EtCO 2 (25–30 mmHg) and normal EtCO 2 (30–40 mmHg).