Objective:To evaluate the effect of preoperative respiratory muscle exercise combined with intraoperative lung protective ventilation strategy on atelectasis in elderly patients undergoing robot-assisted radical prostatectomy.Methods:In the prospective study, a total of 45 patients aged 65-80 years undergoing scheduled robot-assisted radical prostatectomy in First Hospital of Shanxi Medical University from August 2020 to November 2020 were divided into three groups( N=15, each): respiratory muscle exercise combined with lung protective ventilation strategy group(combined group), lung protective ventilation strategy group(pulmonary protective group)and conventional ventilation strategy(control group). Heart rate, systolic blood pressure, diastolic pressure, and pulse oxygen saturation as well as blood gas analysis of arterial blood and the calculated oxygenation index were measured and recorded immediately after establishing invasive artery monitoring in operating room, 10 min after endotracheal intubation, 1 h after the flexitic position, 30 min after tracheal extubation, 24 h after operation in all three groups of patients.The lung compliance values, peak airway pressure, and end-tidal carbon dioxide were recorded at 10 minutes after tracheal intubation, 30 minutes after tracheal extubation, 1 hour after succession position.A single-slice chest CT scan was performed at 1 h after surgery while satisfying the anesthesia recovery steward score ≥ 5.And the percentage of atelectasis area was calculated. Results:The American Society of Anesthesiologisits(ASA)classification of patients was 11/4, 12/3, and 11/4 in the combination group, lung protection group and control group respectively, and the difference was not statistically significant( χ2=0.127, P>0.05). Oxygenation index(mmHg)(1 mmHg=0.133 kPa)at 24 h after surgery was significantly higher in the combined group(351.1±11.2)than in lung protection group(337.0±13.4)( t=3.287, P<0.05). Atelectasis area(Median, Interquartile range)assessed by CT imaging at 30 min after tracheal extubation was 1.92(0.77)% in the combination group, 2.09(1.13)% in lung protection group, and 3.01(1.01)% in control group, with statistically significant difference( χ2 values, 26.036, 12.313, both P<0.05). Atelectasis area at 30 minutes after tracheal extubation was statistically significant smaller in the combination group than in lung protection group( χ2=6.240, P<0.05). Conclusions:Preoperative respiratory muscle exercise combined with intraoperative lung protective ventilation strategy can achieve the better effect of lung protection, reduce the degree of perioperative atelectasis in elderly patients, and improve oxygenation function.

Objective:To explore the effect of spontaneous breathing during induction of general anesthesia on atelectasis in patients undergoing laparoscopic resection of gastrointestinal tumors.Methods:A total of 60 patients aged 18-60 years scheduled for laparoscopic resection of gastrointestinal tumors under general anesthesia in the First Hospital of Shanxi Medical University from October 2021 to August 2022 were selected. The body mass index was 18.5-28.0 kg/m 2 and the American Society of Anesthesiology grade wasⅠ-Ⅱ. All patients were divided into the spontaneous breathing group (group S, 30 cases) and the controlled breathing group (group C, 30 cases) according to the random number table method. Patients in group S received 0.2-0.3 mg/kg etomidate (pumping at the speed of 200 ml/h) and 2 μg/kg remifentanil (slowly injected more than 30 s) for anesthesia induction; patients in group C received 0.2-0.3 mg/kg etomidate and 2 μg/kg remifentanil (slowly injected more than 30 s) and 0.2 mg/kg cisatracurium. After bispectral index (BIS) decreased to 80, the patients had no response to the language stimulation; and then the mask was used to closely fit the face and maintain spontaneous breathing in group S; patients in group C received manual positive pressure ventilation. Atelectasis scores were collected immediately after endotracheal intubation (T 1) and 15 min after transferring to the recovery room (T 3), and oxygenation index (OI) was collected 5 min after endotracheal intubation (T 2) and at T 3. The postoperative pulmonary complication (PPC) on the 3rd day after the operation was recorded. Results:A total of 56 patients were finally enrolled, 27 cases in group S and 29 cases in groups C. Compared with group C, the atelectasis score of group S at T 1 and T 3 decreased [T 1: (2.4±0.8) scores vs. (4.2±0.7) scores, t = -9.12, P < 0.001; T 3: (8.2±1.8) scores vs. (10.5±1.6) scores, t = -4.96, P < 0.001]. The OI increased at T 2 and T 3 in group S [T 2: (334±11) mmHg (1 mmHg = 0.133 kPa) vs. (323±13) mmHg, t = 3.45, P = 0.001; T 3: (362±23) mmHg vs. (347±25) mmHg, t = 2.31, P = 0.025]. The incidence of PPC was 20.7% (6/29) and 18.5% (5/27), respectively in group C and group S on the 3rd day after the operation, and the difference was statistically significant ( χ2 = 0.04, P = 0.838). Conclusions:Maintaining spontaneous breathing during induction of general anesthesia can reduce atelectasis caused by general anesthesia and improve oxygenation for patients undergoing laparoscopic resection of gastrointestinal tumors.

Objective To evaluate the effect of dynamic lung compliance (Cdyn)-guided positive end-expiratory pressure (PEEP) titration on the pulmonary function of elderly patients undergoing roboticassisted radical prostatectomy.Methods Forty patients,aged 65-80 yr,with body mass index of 19-28 kg/m2,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective robotic-assisted laparoscopic radical prostatectomy,were divided into 2 groups (n=20 each) using a random number table method:control group (group C) and PEEP group (group P).After anesthesia induction and endotracheal intubation,all the patients were mechanically ventilated in pressure-controlled ventilation-volume guaranteed mode,with tidal volume 6-8 ml/kg,respiratory rate 12 breaths/min,fraction of inspired oxygen 50％,and inspiratory/expiratory ratio 1 ∶ 2.Respiratory rate was adjusted after onset of pneumoperitoneum to maintain the end-tidal pressure of carbon dioxide at 30-45 mmHg.Immediately after intubation and immediately after establishing pneumoperitoneum-Trendelenburg position,patients received PEEP titration from the lowest PEEP available in the anesthesia machine,with an increment of 2 cmH2O every 4 min until the maximal Cdyn was achieved in group P.Patients in group C received no PEEP during procedure.At 4 min after completion of the first PEEP titration,4 min and 1 and 2 h after completion of the second PEEP titration,and 1 min after closure of abdominal cavity in group P and at 4 min after the end of intubation,4 min and 1 and 2 h after establishing pneumoperitoneum-Trendelenburg position in group C,blood samples from the radical artery were obtained for blood gas analysis,peak airway pressure was recorded,and oxygenation index,driving pressure,alveolar-arterial oxygen difference,and ratio of physical dead space to tidal volume were calculated.Results Compared with group C,the oxygenation index and partial pressure of arterial oxygen were significantly increased,and driving pressure and alveolar-arterial oxygen difference were decreased at each time point (P＜0.05),and no significant change was found in peak airway pressure,ratio of physical dead space to tidal volume or partial pressure of arterial carbon dioxide in group P (P＞0.05).Conclusion Cdyn-guided PEEP titration can improve pulmonary function of elderly patients undergoing robotic-assisted radical prostatectomy.

Objective To evaluate the effect of dynamic lung compliance ( Cydn)-guided positive end-expiratory pressure (PEEP) titration on lung injury in the patients undergoing robot-assisted radical prostatectomy. Methods Forty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients, aged 65-80 yr, with body mass index of 19-28 kg∕m2 , scheduled for elective robot-assisted radical prosta-tectomy under general anesthesia, were divided into 2 groups ( n=20 each) using a random number table method: control group (group C) and PEEP group (group P). Mechanical ventilation was performed ac-cording to preset parameters after tracheal intubation in group C, and PEEP was set by a double titration method after tracheal intubation and after pneumoperitoneum in group P. At 4 min after intubation (T1), 4 min, 1 h and 2 h after establishing pneumoperitoneum-Trendelenburg position ( T2-4 ) , and 1 and 30 min after extubation ( T5,6 ) in group C or at 4 min after completing the first PEEP titration ( T1 ) , 4 min, 1 h and 2 h after completing the second PEEP titration (T2-4) and T5,6 in group P, blood samples were collect-ed from the radial artery for determination of club cell protein 16, surfactant protein-D, tumor necrosis fac-tor-alpha and interleukin-6 concentrations in serum ( by enzyme-linked immunosorbent assay) . Results Compared with group C, the serum concentrations of club cell protein 16 at T2-6 and surfactant protein-D, tumor necrosis factor-alpha and interleukin-6 at T3-6 were significantly decreased in group P (P<0. 05). Conclusion Cydn-guided PEEP titration can reduce the lung injury in patients undergoing robot-assisted radical prostatectomy.

Objective To evaluate the effect of dynamic lung compliance ( Cdyn) -guided positive end-expiratory pressure (PEEP) titration on extravascular lung water in elderly patients undergoing robot-assisted radical prostatectomy. Methods Forty American Society of Anesthesiologists physical statusⅡ orⅢ patients, aged 65-80 yr, with body mass index of 19-28 kg∕m2 , scheduled for elective robot-assisted radical prostatectomy, were divided into 2 groups ( n=20 each) using a random number table method:control group (group C) and PEEP group (group P). In group P, immediately after endotracheal intuba-tion, immediately after establishing pneumoperitoneum-Trendelenburg position and after restoring the supine position, PEEP was set starting from the lowest PEEP allowed by the machine, increasing by 2 cmH2 O ev-ery 4 min until the maximum Cdyn was obtained. PEEP was not set in group C. Immediately after establis-hing the invasive blood pressure monitoring ( T1 ) , at 10 min after the first successful PEEP titration ( T2 ) , 10 min, 1 h and 2 h after the second successful PEEP titration ( T3-5 ) , 10 min after the third successful PEEP titration (T6), and 30 min after tracheal extubation (T7) in group P, or at T1, 10 min after intu-bation ( T2 ) , 10 min, 1 h and 2 h after establishing pneumoperitoneum-Trendelenburg position ( T3-5 ) , 10 min after restoring the supine position ( T6 ) and T7 in group C, blood samples were collected from the radial artery for blood gas analysis, and the oxygenation index was calculated. The B-line score was recor-ded at T1 and T7 . Results Compared with group C, the B-line score was significantly decreased at T7 , and the oxygenation index was increased at T5-7 in group P (P<0. 05). Conclusion Cdyn-guided PEEP titration can decrease the formation of extravascular lung water in elderly patients undergoing robot-assisted radical prostatectomy.

Objective:To evaluate the effect of driving pressure-guided individualized positive end-expiratory pressure (PEEP) titration on atelectasis in elderly patients undergoing robot-assisted radical prostatectomy.Methods:Fifty elderly patients, aged 65-80 yr, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, with body mass index of 19-28 kg/m 2, undergoing elective robot-assisted radical prostatectomy under general anesthesia, were divided into 2 groups ( n=25 each) according to the random number table method: traditional lung-protective ventilation group (group C) and driving pressure-guided individualized PEEP group (group D). The method for setting PEEP was as follows: PEEP 5 cmH 2O was used throughout operation in group C. In group D, the optimal PEEP was titrated after intubation and mechanical ventilation and Trendelenburg position-pneumoperitoneum construction, the initial value was the lowest PEEP allowed by the anesthesia machine, the PEEP was increased by 1 cmH 2O (PEEP≤12 cmH 2O) every 4 min, the plateau pressure and PEEP were simultaneously recorded to calculate the driving pressure, and the corresponding PEEP was considered as the optimal PEEP for the individual when the driving pressure reached the minimum.Ultrasound examination was performed after catheterization of radial artery (T 0), after anesthesia induction (T 1), 4 min after developing optimal PEEP ventilation (T 2, 4 min after developing ventilation in group C), after restoration of body position (T 3), before extubation (T 4), and at 2 h after admission to postanesthesia care unit (T 5). Atelectatic aeration loss scores were recorded at T 0, T 1, T 4 and T 5.Bilateral optic nerve sheath diameter was measured at T 0-4.Arterial blood gas analysis was performed at T 0, T 2, T 3 and T 5, PaO 2 and PaCO 2 were recorded, and oxygenation index was calculated.The postoperative pulmonary complications within 3 days after operation were recorded. Results:Compared with group C, atelectasis aeration loss scores at T 4, 5 and PaCO 2 at T 2, 3 were significantly decreased, and PaO 2 and oxygenation index were increased at T 2, 3, 5 in group D ( P<0.05). There were no significant differences in the bilateral optic nerve sheath diameter and incidence of postoperative pulmonary complications between the two groups ( P>0.05). Conclusion:Driving pressure-guided individualized PEEP can increase intraoperative oxygenation and decrease the development of atelectasis in elderly patients undergoing robot-assisted radical prostatectomy.

Objective:To evaluate the effect of driving pressure (ΔP)-guided PEEP titration on lung injury in elderly patients undergoing robot-assisted radical prostatectomy (RARP).Methods:Forty-six American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients, aged 65-80 yr, with body mass index of 19-28 kg/m 2, with Assess Respiratory Risk in Surgical Patients in Catalonia score assessed as medium to high risk, scheduled for elective RARP, were divided into control group (group C, n=23) and ΔP titration group (group D, n=23) using a random number table method.Volume-controlled mechanical ventilation was used after anesthesia induction and tracheal intubation.In group C, 5 cmH 2O was used to fix PEEP.In group D, the optimal PEEP was titrated after computer-controlled breathing and after establishing Trendelenburg position and pneumoperitoneum, the first titration started from 4 cmH 2O and increased by 1 cmH 2O every 4 min until ΔP reached the minimum value or PEEP increased to 12 cmH 2O, and the second titration was increased in increments as the method described above based on the optimal PEEP of the first titration.At 4 min after completion of the first PEEP titration (T 1, 4 min after mechanical ventilation with fixed PEEP in group C), 2 h after establishment of Trendelenburg position (T 2), 1 min after extubation (T 3) and 2 h after operation (T 4), serum concentrations of Clara cell protein (CC16), surfactant protein D (SP-D), soluble receptor for advanced glycation end-products (sRAGE) and soluble intercellular adhesion molecule-1 (sICAM-1). Pulmonary complications were assessed within 7 days after operation. Results:The serum concentrations of CC16, SP-D, sRAGE and sICAM-1 were significantly higher at T 2-4 than at T 1 in two groups ( P<0.05). Compared with group C, the serum concentrations of CC16, SP-D, sRAGE and sICAM-1 were significantly decreased at T 2-4 ( P<0.05), and no significant change was found in the incidence of pulmonary complications within 7 days after operation in group D ( P>0.05). Conclusions:ΔP-guided PEEP titration can reduce lung injury in elderly patients undergoing RARP.

Objective:To evaluate the effect of continuous positive airway pressure (CPAP) ventilation during induction of anesthesia on perioperative atelectasis and oxygenation in elderly patients.Methods:Forty-six elderly patients of either sex, aged 65-80 yr, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective cerebrovascular intervention surgery under general anesthesia, were divided into 2 groups ( n=23 each) according to the random number table method: control group (group C) and CPAP ventilation group (group CPAP). During induction of anesthesia, CPAP was set at 5 cmH 2O during spontaneous breathing, and PEEP was set at 5 cmH 2O when spontaneous breathing disappeared, and the ventilation mode was changed to pressure-controlled ventilation (PCV) mode in group CPAP. CPAP was not set, and PEEP was set at 0 cmH 2O for PCV when spontaneous breathing disappeared in group C. During anesthesia maintenance, PCV-volume guaranteed mode was used in both groups, and PEEP was set at 5 cmH 2O. Whole lung CT scanning was performed immediately after radial artery catheterization (T 0), at 1 min after endotracheal intubation (T 1), and before tracheal extubation (T 2) at the end of operation to calculate the percentage of atelectasis area at 1 cm above the right diaphragm. At T 0, T 1, T 2 and 30 min after entering postanesthesia care unit (T 3), blood samples from the radial artery were taken to record PaO 2 and PaCO 2 and calculate the oxygenation index (OI). Results:Compared with the baseline at T 0, the percentage of atelectasis area was significantly increased at T 1 and T 2 in two groups ( P<0.05); PaO 2 was significantly increased at T 1 and T 2 and decreased to T 0 level at T 3, OI was decreased at T 1 and T 2 and increased to T 0 level at T 3 in two groups ( P<0.05). Compared with group C, the percentage of atelectasis area was significantly decreased and PaO 2 and OI were increased at T 1 and T 2 in group CPAP ( P<0.05). There was no significant difference in PaCO 2 at each time point between the two groups ( P>0.05). Conclusions:CPAP ventilation during induction of anesthesia can reduce the development of perioperative atelectasis and improve the oxygenation in elderly patients.

Objective:To evaluate the effect of continuous positive airway pressure(CPAP) ventilation strategy during induction of general anesthesia on atelectasis after induction in obese patients.Methods:A total of 86 patients, aged 30-60 yr, with body mass index of 28-35 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱor Ⅲ, scheduled for elective cerebrovascular intervention under general anesthesia, were divided into 2 groups ( n=43 each) using a random number table method: CPAP group (group C) and routine group (group R). Group C received CPAP 5 cmH 2O-assisted ventilation after preoxygenation for spontaneous breathing and disappearance of spontaneous breathing. Chest CT scan and arterial blood gas analysis were performed after entering the operating room (T 1) and 5 min after endotracheal intubation (T 2) to calculate the percentage of atelectasis area and to record PaO 2. Dynamic lung compliance and plateau pressure were recorded at T 2. Mean minute ventilation under controlled breathing, P ETCO 2, and use of vasoactive drugs during induction were recorded. The occurrence of reflux and aspiration during mask ventilation was recorded. The development of pulmonary complications within 3 days after operation was recorded. Results:Compared with group R, the percentage of atelectasis area at T 2 was significantly decreased, PaO 2, dynamic lung compliance and plateau pressure were increased ( P<0.05), and no significant change was found in mean minute ventilation, P ETCO 2, requirement for vasoactive drugs and incidence of pulmonary complications in group C ( P>0.05). No reflux or aspiration was observed during mask ventilation. Conclusions:CPAP (5 cmH 2O) strategy during anesthesia induction can reduce the degree of atelectasis after induction in obese patients.

Objective:To investigate the effects of driving pressure(DP)-guided individualized positive end-expiratory pressure(PEEP)on intraoperative pulmonary function in elderly patients undergoing robot-assisted laparoscopic radical prostatectomy.Methods:This was a retrospective case-control study.A total of 40 elderly patients undergone robot-assisted radical resection of prostate cancer were enrolled and divided into the control group and the DP-guided group(n=20, each group)based on the random number table method.Data on the peak inspiratory pressure(PIP)at time points including 4 min after the first PEEP set(T1), 4 min, 1 hour, 2 hours(T2-4)after the second PEEP set, and 1 min after closing abdomen(T5), lung compliance(Crs), PEEP and the partial pressure of carbon dioxide in end expiratory gas(PetCO 2)were recorded and compared between the two groups.Blood gas analysis was conducted, and the oxygenation index(OI), alveolar-arterial oxygen tension difference(A-aDO 2)and the dead space volume/tidal volume(Vd/Vt)were calculated. Results:Compared with the control group, Crs, OI and PaO 2 were increased and DP, Vd/Vt, A-aDO 2 and PaCO 2 were decreased in the DP-guided group at each time point( P<0.05). PIP showed no significant difference between the two groups at each time point( P>0.05). Compared with T1, PIP and DP were increased and Crs was decreased( P<0.05)in both groups at T2-T4( P<0.05). At T5, PIP was increased in both groups( P<0.05), Crs was decreased and DP was increased in the control group( P<0.05), while Crs and DP had no significant difference in the DP group at T1( P>0.05). OI and PaO 2 showed no significant difference between the two groups at T2-T5( P>0.05). Vd/Vt and PaCO 2 were increased in both groups at T3-T5( P<0.05). Compared with T1 levels, A-aDO 2 was increased in the control group at T3-T5( P<0.05)and in the DP group at T4( P<0.05). Conclusions:DP-guided individualized PEEP can reduce the occurrence of intraoperative atelectasis, improve intraoperative respiratory mechanical state and gas exchange, reduce the risk of potential ventilator-related lung injury and has good lung-protective effects of PEEP in elderly patients undergoing robot-assisted laparoscopic prostatectomy.