Effects of automatic gas control on sevoflurane gas monitor and recovery during pancreatico-duodenectomy operation: prospective randomized study

Background
The aim of the study was to evaluate the effect of automatic gas control (AGC) on sevoflurane gas monitoring, safety, and recovery of patients during pancreatico-duodenectomy operation.
Methods
Forty patients scheduled for the pancreatico-duodenectomy operation were allocated into group I manual gas control group (MGC,  = 20) and group II AGC ( = 20) group. In (the MGC group): The vaporizer set ranged from 3 to 5% Sevoflurane until reaching 1 MAC, fresh gas flow (FGF) 1–2 L/min, and FiO of 0.4 was set. In (the AGC group): Set target FiO of 0.4, end-tidal anesthetic agent (EtSev was set to 1.5–2%) with safely ventilate the patient with an FGF down to 0.3 liters per minute. Hemodynamics, anesthesia gas analysis (FiSev, EtSev, FiO, and EtO), total gas consumption, extubation time, incidence of perioperative hypercapnia, hypoxia, and accidental awareness were recorded.
Results
The volume of sevoflurane administered in the MGC group was in a mean ± standard deviation of 81.20 ± 16.47 ml which was statistically significantly greater than that administered in the AGC group (58.80 ± 10.54), ≤ 0.001. ETSevo, FISevo, and the EtO were significantly larger in the MGC group than in the AGC group. The extubation time was statistically prolonged in the MGC group than in the AGC group (14.10 ± 4.75 versus 7.70 ± 1.59 min,  < 0.001). No patient developed hypoxia, hypercapnia, or awareness in both groups.
Conclusion
AGC maintained the targeted end-tidal sevoflurane concentration with the least sevoflurane consumption. It reduced the manual adjustment of delivered sevoflurane and oxygen. General anesthesia with manual and AGC is safe and maintains hemodynamic stability.