Effect Of Driving Pressure-guided Individualized PEEP Titration On Atelectasis In Elderly Patients Undergoing Robot-assisted Radical Prostatectomy

Objective:To evaluate the impact of driving pressure-guided individualized PEEP titration on atelectasis in elderly patients with robot-assisted radical prostatectomy.Methods:Fifty elderly patients,aged 65-80 years,ASA grade II-III,BMI 19-28 kg-/m²,underwent elective robot-assisted radical prostatectomy under general anesthesia.Patients were randomly divided into two groups（n=25）according to random number table method:traditional lung protective ventilation group（group C）and driving pressure-guided individualized PEEP group（group D）.Setting method of PEEP:In group C,5 cm H2O PEEP was used throughout the operation.The optimal PEEP was titrated for patients in group D after mechanical ventilation with intubation and Trendelenburg position-pneumoperitoneum construction,and the initial value was the lowest PEEP allowed by anesthesia machine.The PEEP was increased by 1 cm H₂O（PEEP≤12 cm H₂O）every 4 min.At this time,plateau pressure and PEEP were recorded to calculate driving pressure.When the driving pressure reaches the minimum,the corresponding PEEP is the optimal PEEP value of the individual.Ultrasound examination was performed after radial artery catheterization（T₀）,after anesthesia induction（T₁）,after Trendelenburg position-pneumoperitoneum established optimal PEEP ventilation 4 minutes（T₂,Group C was after Trendelenburg position-pneumoperitoneum establishment of ventilation 4 minutes）,after position recovery（T₃）,before extubation（T₄）,after admission to PACU 2 hours（T₅）,respectively.And atelectatic aeration loss scores were recorded at T₀,T₁,T₄ and T₅.Bilateral optic nerve sheath diameter（ONSD）was measured at T_0-4.Hemodynamic indexes were recorded at T_0-5.Arterial blood gas analysis was performed at T₀,T₂,T₃ and T₅,when Pa O₂,Pa CO₂ and OI were recorded.The occurrence of postoperative pulmonary complications on the third day after operation was recorded.Results:Compared with T₀,the atelectasis loss scores of the two groups showed an upward trend with time[（group C from 1.7±1.4 to 9.5±2.6,P<0.05）VS（group D from 1.6±1.4 to 4.8±1.5,P<0.05）],the patients in group D reached the highest value of 4.8±1.5 at T₅,and the patients of group C reached the highest value of 10.2±2.3 at T₄.Compared with group C,atelectasis aeration loss score in group D was plummeted at T₄ and T₅（P<0.05）,Pa O₂ and OI were soaring at T_2,3,5,and Pa CO₂ was significantly decreased at T_2,3（P<0.05）.There were no significant resemblance in ONSD,hemodynamics and the incidence of postoperative pulmonary complications on the third day after surgery between the two groups.Conclusion:Driving pressure-guided individualized PEEP can be safely and effectively used in elderly patients with robot-assisted radical prostatectomy,which can significantly reduce the atelectasis loss scores and improve oxygenation in such patients without increasing the risk of intracranial pressure.