Background Mechanical power (MP), as a new comprehensive index to evaluate the effect of mechanical ventilation (MV) on pulmonary respiratory mechanics, can reflect the overall energy transfer in the process of MV, and is closely related to the occurrence of lung injury and the prognosis of patients.Objective To examine the impact of individualized positive end-expiratory pressure (PEEP) guided by electrical impedance tomography (EIT) on the MP in patients undergoing robot-assisted laparoscopic surgery.Methods A secondary analysis of a previous randomized controlled study of 72 patients undergoing robotic hepatobiliary and pancreatic surgery was performed. PEEP settings of patients undergoing surgery were respectively conducted using EIT guidance (PEEPEIT group) and conventional methods (PEEP5 cmH2O group). Respiratory parameters of patients 10 minutes after induction, 60 minutes after PEEP titration with pneumoperitoneum and 10 minutes after deflation were screened from the data, including tidal volume (Vt), respiratory rate (f), peak airway pressure (Ppeak), plateau pressure (Pplat), respiratory compliance (Crs), driving pressure (DP), etc. MP and mechanical energy per breath (MEper breath) received by the respiratory system at different time points of both groups were calculated and compared.Results There were 48 cases in the PEEPEIT group, including 26 males and 22 females, with the mean age of 53.7±14.0 years, in the PEEP5 cmH2O group, there were 24 cases, including 10 males and 14 females, with the mean age of 57.3±14.5 years. No significant difference was found in age and gender between the two groups (P＞0.05). The PEEPEIT group exhibited significantly lower MP than the PEEP5 cmH₂O group at all time points: before pneumoperitoneum (4.54± 1.53 J/min vs 5.49±1.23 J/min), during pneumoperitoneum (6.68±2.35 J/min vs 7.81±2.23 J/min), and after pneumoperitoneum (5.24±1.70 J/min vs 6.09±1.55 J/min) (all P<0.05). Crs was significantly higher in the PEEPEIT group compared to the PEEP5 cmH₂O group during pneumoperitoneum (44.27±11.33 mL/cmH₂O vs 31.88±6.58 mL/cmH₂O) and after pneumoperitoneum (63.56±13.06 mL/cmH₂O vs 48.13±10.59 mL/cmH₂O, both P<0.05). DP was significantly lower in the PEEPEIT group during pneumoperitoneum (11.50±2.08 cmH₂O vs 13.96±2.37 cmH₂O) and after pneumoperitoneum (7.60±1.92 cmH₂O vs 9.75±2.17 cmH₂O) (both P<0.05).Conclusion Individualized PEEP guided by EIT can reduce MP in patients undergoing robotic-assisted hepatobiliary and pancreatic surgery, which may be related to the optimization of Crs and DP.