Effects Of Open-lung Strategy On Cardiopulmonary Function And Postoperative Delirium In Elderly Patients Undergoing Laparoscopic Surgery

PartⅠ Effects of open-lung strategy on cardiopulmonary function in elderly patients undergoing laparoscopic surgeryObjective:To evaluate the effect of open-lung strategy(OLS)on cardiopulmonary function in frail elderly patients undergoing laparoscopic surgery.Methods:Ninety-four frail elderly patients undergoing laparoscopic radical rectal cancer or radical prostate cancer surgery under elective general anesthesia of all genders,aged 65-80 years,with body mass index of 18.5-30.0 kg/m2,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,were divided by random number table into two groups:the non-open lung ventilation(NOLS)group and the open lung ventilation(OLS)group.The patients in the OLS group were given recruitment maneuvers(RM)and individualized positive end-expiratory pressure(PEEP),while patients in the NOLS group were given fixed PEEP(5 an H2O).Cardiac function indexes was measured by transoesophageal echocardiography(TEE)at 10 minutes after endotracheal intubation(T0,baseline value),immediately after the peak of recruitment maneuvers(T1),30 min(T2)and 1 h(T3)after individualised PEEP setting and 10 minutes before the end of surgery(T4),and pulmonary function indexes and optic nerve sheath diameter(ONSD)were recorded at each time point.The levels of serum troponin T(cTnT),creatine kinase-MB(CK-MB)and precursor of type B natriuretic peptide(NT-proBNP)were determined by chemiluminescence before surgery,1d and 2d after surgery in the two groups of patients.The incidence of postoperative pulmonary complications(PPCs)within 7 d after surgery and the postoperative outcome were also recorded in both groups.Results:Eighty-one patients were finally included:41 in the NOLS group and 40 in the OLS group.Compared with the NOLS group,in the OLS group,at T1 and T2,left ventricular end diastolic area,left ventricular ejection fraction,stroke volume,ratio of early mitral flow velocity to early mitral annulus velocity,mitral annular plane systolic excursion,left ventricular global longitudinal strain,right ventricular end diastolic area,right ventricular fractional area change,tricuspid annular plane systolic excusion and right ventricular global longitudinal strain were significantly decreased(P<0.05),and the differences in the above indices at the remaining time points were not statistically significant(P>0.05).At T1-T4,PaO2,oxygenation index,and lung compliance increased,while PaCO2 and alveolar arterial partial pressure difference of oxygen decreased.The total incidence of pulmonary complications was reduced within 7 days after operation,and the retention time of PACU,the time to first out-of-bed activity and the postoperative hospital stay were shortened(P<0.05).The differences in ONSD,serum cTnT,CK-MB,and NT-proBNP concentrations at each time point were not statistically significant(P>0.05).Conclusion:(1)OLS can effectively improve intraoperative respiratory mechanics and oxygenation in elderly patients,reduce the incidence of PPCs,and benefit patient prognosis.(2)OLS does not have significant negative cardiac effects and can be safely used for intraoperative airway management in elderly patients without significant cardiac dysfunction.PartⅡ Effects of open-lung strategy on cerebral oxygenation and postoperative delirium in elderly patients undergoing laparoscopic surgeryObjective:To evaluate the effect of open-lung strategy on cerebral oxygen saturation(rSO2)and postoperative delirium(POD)in elderly patients undergoing laparoscopic surgery.Methods:Eighty-four elderly patients undergoing laparoscopic radical rectal cancer or radical prostate cancer surgery under elective general anesthesia were selected,regardless of gender,aged 65-80 years,with BMI 18.5-30.0 kg/m2 and ASA physical status Ⅱ or Ⅲ.They were divided into two groups by random number table method:the non-open lung strategy(NOLS)group and the open lung strategy(OLS)group.Patients in the OLS group were given small tidal volume ventilation,recruitment maneuvers(RM)and individualized positive end-expiratory pressure(PEEP).In contrast,patients in the NOLS group were given fixed positive end expiratory pressure(5 cm H2O).The rSO2 values were recorded before induction of anesthesia(T0,baseline value),10 min after tracheal intubation(T1),1 h after pneumoperitoneum(T2),2 h after pneumoperitoneum(T3)and 10 min after extubation(T4),and arterial blood was collected for blood gas analysis.The delirium assessment scale was used to assess the occurrence of delirium in patients within three days postoperatively.The levels of serum interleukin-6(IL-6),interleukin-10(IL-10)and calcium-binding protein(S100β)were also measured by ELISA in the two groups of patients before surgery,at the end of surgery,and 1d after surgery.Results:Compared with the NOLS group,patients in the OLS group had significantly higher rSO2 values,PaO2,and PaO2/FiO2 at T2-T4(P<0.05);significantly lower pH values at T3(P<0.05);significantly lower expression levels of IL-6 and S100β and higher expression of IL-10 at the end of surgery and 1 d postoperatively respectively(P<0.05).The overall incidence of POD was significantly lower(P<0.05)on the first day and within three days postoperatively.The rSO2 values were significantly lower in the NOLS group at T2-T4 compared with those at T0(P<0.05).The expression levels of IL-6,IL-10 and S100β were significantly higher in both groups at the end of surgery and 1 d after surgery compared with preoperative levels(P<0.05).Conclusion:(1)OLS can optimize the oxygenation function of elderly patients and improve patients’ rSO2.(2)OLS can reduce the postoperative inflammatory response and significantly decrease the risk of POD in elderly patients undergoing laparoscopic surgery.