While few studies have determined the optimal intra-abdominal CO2 insufflation pressure to achieve optimal surgical condition during LCs with deep-NMB and moderate-NMB in laparoscopic cholecystectomy (LC), previous studies suggested that the use of deep neuromuscular blockade (deep-NMB) can improve surgical condition and reduce the pressure for CO2 insufflation to achieve "optimal surgical space condition".

this difference in the pressure of intra-abdominal CO2 insufflation due to different strategies employing deep-NMB and moderate-NMB for LC may produce possible difference in patient's respiratory pattern and cerebral oxygenation. Although previous study (studies) showed that intra-abdominal CO2 insufflation (10-12 mmHg) decreases cerebral oxy-hemoglobin (HbO2) and total Hb measured by near-infrared spectroscopy (NIRS) during laparoscopic cholecystectomy (LC), few studies have speculated possible impact of different degree of NMB and intra-abdominal CO2 insufflation pressure on patient's cardiorespiratory profile and cerebral oxygenation, so far.

The present study determines and compares the changes CO2 absorption and cerebral oxygenation (cerebral perfusion) after applying CO2 insufflation with different intra-peritoneal pressure 8 vs 12 mmHg during deep-NMB.

Inclusion Criteria:

• cholecystitis
• provision of written informed consent

Exclusion Criteria:

• COPD
• asthma
• low LV ejection fraction