Volume-controlled Ventilation Group Research Articles

A clinical trial of volume- versus pressure-controlled intraoperative ventilation during laparoscopic bariatric surgeries.

Intra-operative ventilation is often challenging in patients with morbid obesity undergoing bariatric surgery. To test the noninferiority of pressure-controlled ventilation (PCV) to volume-controlled ventilation (VCV) in respiratory mechanics. Bariatric Surgery Center, Iran. In a randomized open-labeled clinical trial, 66 individuals with morbid obesity undergoing laparoscopic bariatric surgeries underwent intraoperative ventilation with either PCV or VCV. The measurements taken were peak and mean airway pressures (H2O), partial pressure of arterial oxygen (PaO2), partial pressure of arterial carbon dioxide (PaCO2) and end-tidal carbon dioxide (CO2). We additionally collected pulse-oximetric oxygen saturation, inspiratory concentration of oxygen (FiO2), and hemodynamic variables. Data were analyzed with repeated measures over the time of intubation, after peritoneal insufflation, and every 15 minutes, thereafter up to one hour. PCV mode was successful to sustain adequate ventilation in 97% of the patients, which was similar to the 94% success rate of the VCV mode. Peak airway pressure increased 6 cmH2O and end-tidal CO2 rose by 5 mm Hg after abdominal insufflation in both groups (P = .850 and .376). Alveolar-arterial oxygen gradient similarly increased within 30 minutes after tracheal intubation both in PCV and VCV groups, with small trend of being higher in the VCV group. The ratio of dead space to tidal volumes (VD/VT) did not have a meaningful change (P = .724). PCV was noninferior to VCV during laparoscopic bariatric surgery. Either mode of ventilation could be alternatively used during the anesthesia care of these patients.

Comparative study between volume-controlled ventilation and pressure-controlled ventilation in prevention of postoperative pulmonary atelectasis in morbidly obese patients undergoing laparoscopic gastric sleeve surgery

BackgroundAtelectasis can result during general anesthesia from mechanical ventilation and decrease in lung volume particularly in morbidly obese patients undergoing abdominal laparoscopic sleeve surgery, which may result in the development of postoperative pulmonary complications (PPCs), including hypoxemia and pneumonia, with an increased risk of postoperative morbidity and mortality.ObjectiveTo compare between volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) in prevention of postoperative pulmonary atelectasis in morbidly obese patients undergoing laparoscopic gastric sleeve surgery.MethodsThis is a randomized prospective comparative clinical study with a total of 52 morbidly obese patients who were randomly divided into 2 groups; 26 patients in group (V) for VCV and 26 in group (P) for PCV arterial blood samples were obtained, and PaCO2, PaO2, and SaO2 were obtained and recorded. ABG analyses were also obtained 30 min, 12 h, and 24 h post-extubation, and PaCO2, PaO2, and SaO2 were obtained and recorded.ResultsThe results of this study revealed no significant differences between PCV and VCV as regards the incidence of postoperative lung atelectasis immediately postoperative (69.2% with VCV vs 61.5% with PCV, p = 0.368), 12 h postoperative (61.5% with VCV vs 53.8% with PCV, p = 0.282), and 24 h postoperative (53.8% with VCV vs 46.2% with PCV, p = 0.325). There were also no significant differences between VCV and PCV as regards baseline, intra-, and post-operative PaCO2 levels as well as baseline and postoperative SaO2 and PaO2 values. However, PCV showed better intraoperative oxygenation compared to VCV. SaO2 was 96.32% ± 1.85 and 97.25% ± 1.37 in VCV and PCV groups respectively (p = 0.027) while PaO2 was 212.75 mmHg ± 20.13 and 225.8 mmHg ± 18.69 in VCV and PCV groups respectively (p = 0.011).ConclusionDespite a slight improvement in intraoperative oxygenation parameters (PO2, SaO2) with PCV than VCV, there is no significant difference between VCV and PCV in the prevention of postoperative pulmonary atelectasis; moreover, there is no difference in postoperative oxygenation parameters in morbidly obese patients who undergo laparoscopic sleeve surgery.

Comparison between volume-controlled ventilation and pressure-controlled volume-guaranteed ventilation in postoperative lung atelectasis using lung ultrasound following upper abdominal laparotomies: a prospective randomized study

BackgroundAtelectasis is a common side effect of general anesthesia. Prevention of lung atelectasis, carbon dioxide retention, and chest infection would improve the quality of medical care and decrease hospital stay and costs. The aim of this study was to compare the effects of volume-controlled ventilation (VCV) and pressure-controlled volume-guaranteed ventilation (PCVG) on postoperative lung atelectasis using lung ultrasound (LUS) following upper abdominal laparotomies.ResultsSixty patients (male and female) scheduled for upper abdominal laparotomies. They were randomly allocated into two equal groups: Group A (n = 30): received intraoperative volume-controlled ventilation (VCV) mode and group (n = 30): received intraoperative pressure-controlled ventilation volume-guaranteed (PCV-VG) mode. Arterial blood samples were obtained immediately after extubation, and 30, 120, 240, and 360 min postextubation. Lung ultrasound was done intraoperatively at 30 min from induction, immediate, and 120 and after 360 min postoperatively. There was difference between two groups favoring PCV-VG group but that difference failed to be statically significant regarding arterial partial pressure of oxygen (PaO2) and arterial carbon dioxide tension (PaCo2) between the two groups in preoperative, immediate postoperative, and 120, 240, and 360 min postoperative. Arterial oxygen saturation (SaO2) was significantly lower among patients in the VCV group immediate postextubation compared with patients in group PCV-VG (p value = 0.009*). Although signs of atelectasis were low in group B, 36.7% of the patients showed normal lung ultrasound, 63.3% showed various abnormalities, 46.7% showed the presence of lung pulse (vertical rhythmic movement synchronous with cardiac pulsation through motionless lung), and 46.7% showed B lines (vertical lines indicate abnormal lung aeration), while 30% of the patients showed the absence of A-lines (indicates the absence of lung sliding and abnormal lung aeration). Also, some patients demonstrated more than one sign. However, there was no a significant difference between the two groups both showed atelectasis immediate, 2 h and 6 h postoperatively.ConclusionPCV-VG offered no significant advantage over VCV regarding the occurrence of the postoperative atelectasis. However, we prefer to use PCV-VG as postoperative hypoxia and atelectasis was much less in that mode. Further, large-scale studies are required to confirm these findings and to establish a definite conclusion.

Pressure-Controlled Ventilation-Volume Guaranteed Mode Combined with an Open-Lung Approach Improves Lung Mechanics, Oxygenation Parameters, and the Inflammatory Response during One-Lung Ventilation: A Randomized Controlled Trial.

We evaluated the effectiveness of pressure-controlled ventilation-volume guaranteed (PCV-VG) mode combined with open-lung approach (OLA) in patients during one-lung ventilation (OLV). First, 176 patients undergoing thoracoscopic surgery were allocated randomly to four groups: PCV+OLA (45 cases, PCV-VG mode plus OLA involving application of individualized positive end-expiratory pressure (PEEP) after a recruitment maneuver), PCV (44 cases, PCV-VG mode plus standard lung-protective ventilation with fixed PEEP of 5 cmH2O), VCV+OLA (45 cases, volume-controlled ventilation (VCV) plus OLA), and VCV (42 cases, VCV plus standard lung-protective ventilation). Mean airway pressure (Pmean), dynamic compliance (Cdyn), PaO2/FiO2 ratio, intrapulmonary shunt ratio (Qs/Qt), dead space fraction (VD/VT), and plasma concentration of neutrophil elastase were obtained to assess the effects of four lung-protective ventilation strategies. At 45 min after OLV, the median (interquartile range (IQR)) Pmean was higher in the PCV+OLA group (13.00 (12.00, 13.00) cmH2O) and the VCV+OLA group (12.00 (12.00, 14.00) cmH2O) than in the PCV group (11.00 (10.00, 12.00) cmH2O) and the VCV group (11.00 (10.00, 12.00) cmH2O) (P < 0.05); the median (IQR) Cdyn was higher in the PCV+OLA group (27.00 (24.00, 32.00) mL/cmH2O) and the VCV+OLA group (27.00 (22.00, 30.00) mL/cmH2O) than in the PCV group (23.00 (21.00, 25.00) mL/cmH2O) and the VCV group (20.00 (18.75, 21.00) mL/cmH2O) (P < 0.05); the median (IQR) Qs/Qt in the PCV+OLA group (0.17 (0.16, 0.19)) was significantly lower than that in the PCV group (0.19 (0.18, 0.20)) and the VCV group (0.19 (0.17, 0.20)) (P < 0.05); VD/VT was lower in the PCV+OLA group (0.18 ± 0.05) and the VCV+OLA group (0.19 ± 0.07) than in the PCV group (0.21 ± 0.07) and the VCV group (0.22 ± 0.06) (P < 0.05). The concentration of neutrophil elastase was lower in the PCV+OLA group than in the PCV, VCV+OLA, and VCV groups at total-lung ventilation 10 min after OLV (162.47 ± 25.71, 198.58 ± 41.99, 200.84 ± 22.17, and 286.95 ± 21.10 ng/mL, resp.) (P < 0.05). In conclusion, PCV-VG mode combined with an OLA strategy leads to favorable effects upon lung mechanics, oxygenation parameters, and the inflammatory response during OLV.

Effect of Pressure-Controlled Ventilation-Volume Guaranteed on One-Lung Ventilation in Elderly Patients Undergoing Thoracotomy

BackgroundVolume-controlled ventilation (VCV) in one-lung ventilation (OLV) is most commonly used in thoracotomy, but pressure-controlled ventilation-volume guaranteed (PCV-VG) is used in elderly patients to improve arterial oxygenation, reduce inflammatory factors, and decrease acute lung injury (ALI). The purpose of this study was to investigate the effects of these 2 different ventilation modes – VCV versus PCV-VG – during OLV in elderly patients undergoing thoracoscopic lobectomy.Material/MethodsSixty patients undergoing thoracoscopic lobectomy from September 2018 to February 2019 at Cangzhou Central Hospital, Hebei, China were randomly assigned to a VCV group or a PCV-VG group. Pulmonary dynamic compliance (Cdyn), peak inspiratory pressure (PIP), arterial blood gas, and inflammatory factors were monitored to assess lung function. The Clinical Trial Registration Identifier number is ChiCTR1800017835.ResultsCompared with the VCV group, PIP in the PCV-VG group was significantly lower (P=0.01) and Cdyn was significantly higher at 30 min after one-lung ventilation (P=0.01). MAP of the PCV-VG group was higher than in the VCV group (P=0.01). MAP of the PCV-VG group was also higher than in the VCV group at 30 min after one-lung ventilation (P=0.01). The concentration of neutrophil elastase (NE) in the PCV-VG group was significantly lower than in the VCV group (P=0.01).ConclusionsCompared with VCV, PCV-VG mode reduced airway pressure in patients undergoing thoracotomy and also decreased the release of NE and reduced inflammatory response and lung injury. We conclude that PCV-VG mode can protect the lung function of elderly patients undergoing thoracotomy.

Comparison of pressure- and volume-controlled ventilation during laparoscopic colectomy in patients with colorectal cancer

This study investigated the differences in airway mechanics and postoperative respiratory complications using two mechanical ventilation modalities and the relationship between biomarkers and postoperative respiratory complications in patients with colorectal cancer who underwent laparoscopic colectomy. Forty-six patients with colorectal cancer scheduled for laparoscopic colectomy were randomly allocated to receive mechanical ventilation using either volume-controlled ventilation (VCV) (n = 23) or pressure-controlled ventilation (PCV) (n = 23). Respiratory parameters were measured and plasma sRAGE and S100A12 were collected 20 minutes after the induction of anesthesia in the supine position without pneumoperitoneum (T1), 40 minutes after 30° Trendelenburg position with pneumoperitoneum (T2), at skin closure in the supine position (T3), and 24 hours after the operation (T4). The peak airway pressure (Ppeak) at T2 was lower in the PCV group than in the VCV group. The plateau airway pressures (Pplat) at T2 and T3 were higher in the VCV group than in the PCV group. Plasma levels of sRAGE at T2 and T3 were 1.6- and 1.4-fold higher in the VCV group than in the PCV group, while plasma S100A12 levels were 2.6- and 2.2-fold higher in the VCV group than in the PCV group, respectively. There were significant correlations between Ppeak and sRAGE, and between Ppeak and S100A12. There were also correlations between Pplat and sRAGE, and between Pplat and S100A12. sRAGE and S100A12 levels at T2 and T3 showed high sensitivity and specificity for postoperative respiratory complications. Postoperative respiratory complications were 3-fold higher in the VCV group than in the PCV group. In conclusion, during laparoscopic colectomy in patients with colorectal cancer, the peak airway pressure, the incidence of postoperative respiratory complications, and plasma sRAGE and S100A12 levels were lower in the PCV group than in the VCV group. Intra- and postoperative plasma sRAGE and S100A12 were useful for predicting the development of postoperative respiratory complications.

Comparison of pressure-controlled volume-guaranteed ventilation and volume-controlled ventilation in obese patients during gynecologic laparoscopic surgery in the Trendelenburg position

Background and objectivesThe aim of this study was to investigate the efficacy of the pressure-controlled, volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) modes for maintaining adequate airway pressures, lung compliance and oxygenation in obese patients undergoing laparoscopic hysterectomy in the Trendelenburg position. MethodsPatients (104) who underwent laparoscopic gynecologic surgery with a body mass index between 30 and 40 kg.m−2 were randomized to receive either VCV or PCV-VG ventilation. The tidal volume was set at 8 mL.kg−1, with an inspired oxygen concentration of 0.4 with a Positive End-Expiratory Pressure (PEEP) of 5 mmHg. The peak inspiratory pressure, mean inspiratory pressure, plateau pressure, driving pressure, dynamic compliance, respiratory rate, exhaled tidal volume, etCO2, arterial blood gas analysis, heart rate and mean arterial pressure at 5 minutes after induction of anesthesia in the and at 5, 30 and 60 minutes, respectively, after pneumoperitoneum in the Trendelenburg position were recorded. ResultsThe PCV-VG group had significantly decreased peak inspiratory pressure, mean inspiratory pressur, plateau pressure, driving pressure and increased dynamic compliance compared to the VCV group. Mean PaO2 levels were significantly higher in the PCV-VG group than in the VCV group at every time point after pneumoperitoneum in the Trendelenburg position. ConclusionsThe PCV-VG mode of ventilation limited the peak inspiratory pressure, decreased the driving pressure and increased the dynamic compliance compared to VCV in obese patients undergoing laparoscopic hysterectomy. PCV-VG may be a preferable modality to prevent barotrauma during laparoscopic surgeries in obese patients.

Comparação entre ventilação garantida por volume controlado por pressão e ventilação controlada por volume em pacientes obesos durante cirurgia laparoscópica ginecológica na posição de Trendelenburg

Background and objectivesThe aim of this study was to investigate the efficacy of the pressure‐controlled, volume‐guaranteed (PCV‐VG) and volume‐controlled ventilation (VCV) modes for maintaining adequate airway pressures, lung compliance and oxygenation in obese patients undergoing laparoscopic hysterectomy in the Trendelenburg position. MethodsPatients (104) who underwent laparoscopic gynecologic surgery with a body mass index between 30 and 40kg.m-2 were randomized to receive either VCV or PCV‐VG ventilation. The tidal volume was set at 8mL.kg-1, with an inspired oxygen concentration of 0.4 with a Positive End‐Expiratory Pressure (PEEP) of 5mmHg. The peak inspiratory pressure, mean inspiratory pressure, plateau pressure, driving pressure, dynamic compliance, respiratory rate, exhaled tidal volume, etCO2, arterial blood gas analysis, heart rate and mean arterial pressure at 5minutes after induction of anesthesia in the and at 5, 30 and 60minutes, respectively, after pneumoperitoneum in the Trendelenburg position were recorded. ResultsThe PCV‐VG group had significantly decreased peak inspiratory pressure, mean inspiratory pressur, plateau pressure, driving pressure and increased dynamic compliance compared to the VCV group. Mean PaO2 levels were significantly higher in the PCV‐VG group than in the VCV group at every time point after pneumoperitoneum in the Trendelenburg position. ConclusionsThe PCV‐VG mode of ventilation limited the peak inspiratory pressure, decreased the driving pressure and increased the dynamic compliance compared to VCV in obese patients undergoing laparoscopic hysterectomy. PCV‐VG may be a preferable modality to prevent barotrauma during laparoscopic surgeries in obese patients.

Impact of the modality of mechanical ventilation on bleeding during pituitary surgery: A single blinded randomized trial.

Background:Bleeding modifies the surgeon's view of the field during transsphenoidal endoscopic pituitary surgery. Since ventilation can alter venous return, we compared the effect of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) on intraoperative bleeding.Methods:Eighty-six patients were randomized to VCV or PCV in this single blinded study; comparisons concerned 42 in the PCV group and 43 in the VCV group.Results:Intraoperative bleeding, the primary endpoint, did not differ between groups whether analysis focused on 7 levels of the score, from minimal bleeding to bleeding with significant change in the conduct of surgical procedure (P = .89) or on a stratification into 3 categories, mild, moderate, and major (P = .47). Median [interquartile range] peak airway pressure was lower in the PCV group (13.5 [12.5–15] vs 16.3 [14.4–19.1] cm H2O, P < .001) while mean airway pressures were similar (P = .08). Means ± SD of tidal volumes were lower in the VCV group when expressed as absolute values (470.6 ± 84 vs 434.7 ± 71.7 ml, P = .05) or as tidal volume/theoretical ideal weight ratio (6.7 [6.5–7] vs 7.2 [6.9–7.9], P < .001). The 2 groups were similar for postoperative complications and number of patients cured.Conclusion:In conclusion, ventilation mode does not influence intraoperative bleeding during transsphenoidal pituitary surgery.Trial registration:Clinicaltrials.gov identifier: NCT01891838; July 3, 2013

Lung ultrasound score-based perioperative assessment of pressure-controlled ventilation-volume guaranteed or volume-controlled ventilation in geriatrics: a prospective randomized controlled trial.

PurposeRecent studies have shown the potential benefits of pressure-controlled ventilation-volume guaranteed (PCV-VG) compared to volume-controlled ventilation (VCV), but the results were not impressive. We assessed the effects of PCV-VG versus VCV in elderly patients by using lung ultrasound score (LUS).Patients and methodsElderly patients (aged 65–90 years) scheduled for hip joint surgery were randomly assigned to either the PCV-VG or VCV group during general anesthesia. LUS and mechanical ventilator parameters were evaluated before induction, 30 mins after a semi-lateral position change, during supine repositioning before awakening, and 15 mins after arrival to the post-anesthesia care unit (PACU). Pulmonary function tests were performed before and after surgery. Other recovery indicators were also assessed in the PACU.ResultsA total of 76 patients (40 for PCV-VG and 36 for VCV) were included this study. Demographic data showed no significant difference between the two groups. In both groups, LUSs before induction were significantly lower than those at other time points. LUSs of the VCV group were significantly increased during perioperative periods compared with the PCV-VG group (p=0.049). Visualized LUS modeling suggested an intuitive difference in the two groups and unequal distribution in lung aeration. Higher dynamic compliance and lower inspiratory peak pressure were observed in the PVC-VG group compared to the VCV group (33.54 vs 27.36, p<0.001; 18.93 vs 21.19, p<0.001, respectively). Postoperative forced vital capacity of the VCV group was lower than that of PCV-VG group, but this result was not significant (2.06 vs 1.79, respectively; p=0.091). The other respiratory data are comparable between the two groups.ConclusionThe PCV-VG group showed better LUS compared with the VCV group. Moreover, LUS modeling in both groups suggests non-homogeneous and positional change in lung aerations during surgery.Clinical trial registrationThis study was registered at the UMIN clinical trials registry (unique trial number: UMIN000029355; registration number: R000033510)

Effects of aerosol inhalation on respiratory mechanical parameters under different ventilation patterns and ventilator parameters

To investigate the effects of aerosol inhalation on respiratory mechanical parameters under different ventilation patterns and ventilator parameters in patients on mechanical ventilation and simulated model of aqualung in vitro. (1) Clinical research: the patients needed sedative undergoing mechanical ventilation admitted to intensive care unit (ICU) of Qingdao Municipal Hospital from January 2016 to January 2018 were enrolled. They were randomly divided into volume controlled ventilation (VCV) group and pressure controlled ventilation (PCV) group according to random number table. Main parameters setting of respirator: the predetermined tidal volume (VT) was set at 500 mL in the VCV group; the preset pressure was regulated, so that when the atomizer was connected to the atomization device, the VT was nearly equal to or slightly larger than 500 mL in the PCV group. Respiratory mechanical indices [peak airway pressure (Ppeak), inspiratory tidal volume (VTi), exhaled tidal volume (VTe)] were recorded before atomization (atomized oxygen flow was 0) and 10 minutes after the beginning of atomization under the condition of 7 L/min and 9 L/min of atomized oxygen flow respectively. (2) Simulated scuba test in vitro: the ventilator was connected to the simulated scuba, and an external mechanical ventilation model was constructed. They were divided into VCV group and PCV group according to ventilation mode. Main parameters setting of respirator: VCV group was given 450, 550, 650 mL preset VT, and PCV group was given 12, 16, 20 cmH2O (1 cmH2O = 0.098 kPa) preset suction pressure. The changes in respiratory mechanical indexes were observed under different ventilation patterns and ventilator parameters of 0 (only connected with atomizing device), 5, 7, 9 L/min atomizing oxygen flow. (1) Clinical research results: all 77 patients were enrolled in the final analysis, including 20 patients with 7 L/min of atomized oxygen flow under VCV mode, 18 patients with 9 L/min of atomized oxygen flow, and 21 patients with 7 L/min of atomized oxygen flow under PCV mode and 18 patients with 9 L/min of atomized oxygen flow. Under VCV mode, the levels of Ppeak and VTe were increased with the increase in atomized oxygen flow, and there was significant difference at 9 L/min as compared with those before atomization [Ppeak (cmH2O): 29.44±4.58 vs. 24.39±4.64, VTe (mL): 896.26±24.91 vs. 497.61±8.67, both P < 0.05]. There was no significant change in VTi, and no significant difference at 9 L/min of atomized oxygen flow as compared with that before atomization (mL: 494.67±3.07 vs. 492.61±6.05, P > 0.05). Under PCV mode, with the increase in oxygen atomization flow, VTi was decreased gradually, and VTe was increased gradually, with significant difference as compared with those before atomization when the atomized oxygen flow was 9 L/min [VTi (mL): 322.78±17.75 vs. 518.17±8.97, VTe (mL): 730.89±31.20 vs. 519.00±9.06, both P < 0.05]. There was no significant change in Ppeak, and no significant difference at 9 L/min of atomized oxygen flow as compared with that before atomization (cmH2O: 21.44±2.23 vs. 21.39±2.55, P > 0.05). (2) Simulated scuba results in vitro: under VCV mode, VTe monitored by respirator and VT showed by simulated scuba in different preset VT groups were continuously increased with the increase in oxygen atomization flow, while VTi monitored by ventilator was not significantly changed. At 10 minutes after the beginning of atomization, the VTi monitored by ventilator in different preset VT groups was significantly lower than VT showed by simulated water lung (mL: 649.67±5.03 vs. 840.00±10.00 at 650 mL of preset VT and 9 L/min of atomized oxygen flow, P < 0.05), and VTe was significantly higher than VT showed by simulated water lung (mL: 1 270.33±11.06 vs. 840.00±10.00 at 650 mL of preset VT and 9 L/min of atomized oxygen flow, P < 0.05). Under PCV mode, with the increase in atomized oxygen flow, VTi monitored by ventilator in different preset suction pressure groups was decreased gradually, and VTe was increased gradually, but Ppeak monitored by ventilator did not changed significantly. At 10 minutes after the beginning of atomization, the VTi monitored by ventilator in different preset suction pressure groups was significantly lower than VT showed by simulated water lung (mL: 917.33±4.51 vs. 1 103.33±5.77 at 20 cmH2O of preset suction pressure and 9 L/min of atomized oxygen flow, P < 0.05), and VTe was significantly higher than VT showed by simulated water lung (mL: 1 433.33±4.73 vs. 1 103.33±5.77 at 20 cmH2O of preset suction pressure and 9 L/min of atomized oxygen flow, P < 0.05). Under the VCV mode, the oxygen flow outside the atomization could lead to the increase in VT of the patient side, while under the PCV mode, the VT and Ppeak in the patient side had no significant change. Both VTi and VTe monitored by ventilator could not reflect the patient's VT under either VCV or PCV mode.

Comparison between volume-controlled and pressure-controlled ventilation in COPD patients undergoing laparoscopic cholecystectomy

Background: Chronic obstructive pulmonary disease (COPD) is a well-known independent risk factor for the development of postoperative pulmonary complications. Managing ventilation and oxygenation during laparoscopic cholecystectomy (with creation of pneumoperitoneum) in these patients presents many challenges. Aim of this study: was to compare between volume-controlled and pressure-controlled ventilation in COPD patients undergoing laparoscopic cholecystectomy. Methods: A case control study was conducted on 60 participants aged between 18 and 60 years, diagnosed with COPD and scheduled for laparoscopic cholecystectomy. To start with, all patients received volume-controlled ventilation (VCV). Fifteen minutes after creation of pneumoperitoneum, they were randomized to receive either VCV (Group A) or pressure-controlled ventilation; PCV (Group B). Hemodynamics, ventilatory parameters, arterial blood gas analyses were noted. All data were analyzed statistically. Results: There was no significant difference between study groups as regards hemodynamic variables. Peak airway pressure was significantly lower in PCV group compared with VCV group. Mean airway pressure was significantly higher in PCV group compared with VCV group. As regards arterial blood gas analyses, there was no significant difference between study groups as regards PaO2 and SpO2. Patients in PCV group had higher PaCO2 (yet not clinically significant) at 35 min, compared with patients in VCV group. Conclusion: PCV and VCV were generally effective in maintaining adequate ventilation, oxygenation and hemodynamic stability. Peak airway pressure was significantly lower in PCV group compared with VCV group, thus decreasing the risk of barotrauma. PCV may be a better choice than VCV in COPD patients undergoing laparoscopic cholecystectomy.

Comparison between volume-controlled and pressure-controlled ventilation in COPD patients undergoing laparoscopic cholecystectomy

Background: Chronic obstructive pulmonary disease (COPD) is a well-known independent risk factor for the development of postoperative pulmonary complications. Managing ventilation and oxygenation during laparoscopic cholecystectomy (with creation of pneumoperitoneum) in these patients presents many challenges. Aim of this study: was to compare between volume-controlled and pressure-controlled ventilation in COPD patients undergoing laparoscopic cholecystectomy. Methods: A case control study was conducted on 60 participants aged between 18 and 60 years, diagnosed with COPD and scheduled for laparoscopic cholecystectomy. To start with, all patients received volume-controlled ventilation (VCV). Fifteen minutes after creation of pneumoperitoneum, they were randomized to receive either VCV (Group A) or pressure-controlled ventilation; PCV (Group B). Hemodynamics, ventilatory parameters, arterial blood gas analyses were noted. All data were analyzed statistically. Results: There was no significant difference between study groups as regards hemodynamic variables. Peak airway pressure was significantly lower in PCV group compared with VCV group. Mean airway pressure was significantly higher in PCV group compared with VCV group. As regards arterial blood gas analyses, there was no significant difference between study groups as regards PaO2 and SpO2. Patients in PCV group had higher PaCO2 (yet not clinically significant) at 35 min, compared with patients in VCV group. Conclusion: PCV and VCV were generally effective in maintaining adequate ventilation, oxygenation and hemodynamic stability. Peak airway pressure was significantly lower in PCV group compared with VCV group, thus decreasing the risk of barotrauma. PCV may be a better choice than VCV in COPD patients undergoing laparoscopic cholecystectomy.

The Effect of Pressure Controlled Ventilation on Pulmonary Mechanics in Prone Patients Undergoing Elective Spine Surgeries: Comparative Study with Volume Controlled Ventilation

Abstract Background: As patients turned into prone position expe-rienced more decrease in lung compliance than those on supine position, this prospective, randomized study was designed to compare the effect of PCV and volume-controlled ventilation (VCV) on lung mechanics and heamodynamics in the prone position using the Wilson frame during elective lumbar spine surgery.Patients and Methods: Sixty patients scheduled for elective lumbar spine surgery were randomly allocated to receive mechanical ventilation using either the VCV (n=30) or PCV (n=30) mode. Respiratory variables (peak airway pressure, mean airway pressure, shunt fraction, alveolar-arterial oxygen gradient). Dynamic compliance (Cdyn) of the respiratory system was calculated as VT/ (Ppeak-PEEP). The alveolar dead space-to-tidal volume ratio (VD/VT) will be estimated using the Hardman and Aitkenhead equation: VD/VT=1. 135– (PaCO2-ETCO2)/(PaCO2-0. 005). Results: The Ppeak in the PCV group was lower than that in the VCV group throughout the study period (p-value=0.961 and 0. 0.109 at supine position and prone position, respectively) and was increased at prone position compared with supine position in both groups. Cdyn was decreased from supine to prone position in both groups. However, the Cdyn in the PCV group was higher than that in the VCV group during the study period however it is only statistically significant after 1.5 and 2hrs. The arterial oxygen tension was comparable between the 2 groups during the study period.Conclusions: PCV provides lower Ppeak compared with VCV when the ventilator is set to deliver the same tidal volume and variable respiratory rate to maintain a constant end-tidal carbon dioxide tension in patients undergoing pos-terior lumbar spine surgery in the prone position using the Wilson frame.

Effects of volume-controlled ventilation vs. pressure-controlled ventilation on respiratory function and inflammatory factors in patients undergoing video-assisted thoracoscopic radical resection of pulmonary carcinoma

The best ventilation approach for patients undergoing video-assisted thoracic surgery (ATS) for pulmonary carcinoma remains undefined. This study aimed to assess hemodynamics, airway pressure, arterial blood gas, and inflammatory factors in patients undergoing VATS for pulmonary carcinoma under volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV). This was a prospective study of 60 patients with pulmonary carcinoma treated at a tertiary center in 2015-2016. The subjects were randomized to the VCV or PCV group after anesthesia and total lung ventilation (TLV). Hemodynamics and blood gas parameters were compared between the two groups pre-OLV (one-lung ventilation) (T1) and after 30 (T2), 60 (T3), and 120 (T4) minutes of OLV. Radial artery blood was collected to measure interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α levels. Hemodynamic and blood gas parameters were similar between the two groups (all P>0.05). During OLV, airway resistance (RAW) was significantly lower in the PCV group compared with the VCV group at T2 (26.0±3.8 vs. 29.9±7.3 cmH2O/L/s), T3 (26.0±3.7 vs. 30.2±7.7 cmH2O/L/s), and T4 (25.8±4.1 vs. 29.6±6.7 cmH2O/L/s). Similar trends were found for peak pressure (Ppeak) and plateau pressure (Pplat). Mean pressure (Pmean) was similar between the two groups. Compared with the PCV group, TNF-α and IL-6 levels in the VCV group were significantly increased (all P<0.05). The levels of the anti-inflammatory mediator IL-10 were higher in the PCV group compared with the VCV group. PCV for OLV during radical resection of pulmonary carcinoma by VATS could reduce Ppeak and downregulate pro-inflammatory factors, likely decreasing airway injury.

Efficacy of PCV-VG mode for lung protective ventilation in patients requiring one-lung ventilation during thoracoscopic surgery

Objective To evaluate the efficacy of pressure-controlled volume-guaranteed (PCV-VG) mode for lung protective ventilation in patients requiring one-lung ventilation (OLV) during thoracoscopic surgery. Methods Sixty patients, aged 50-70 yr, with body mass index of 18-26 kg/m2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective radical resection of esophageal cancer performed via video-assisted thoracoscope under general anesthesia, were divided into 2 groups (n=30 each) using a random number table: volume-controlled ventilation group (group V) and PCV-VG group (group P). The ventilator settings were adjusted, with a tidal volume 10 ml/kg and respiratory rate 10-12 breaths/min during two-lung ventilation, and with a tidal volume 6 ml/kg and respiratory rate 12-16 breaths/min during OLV.The inspiratory/expiratory ratio was 1∶2, pressure restriction was 35 cmH2O, and 33% oxygen was inhaled at 2 L/min.The end-tidal pressure of carbon dioxide was maintained at 35-40 mmHg.Visual analog scale score was maintained ≤ 3 after operation.After admission to the operation room (T0) and at 1, 3 and 7 days after operation (T1-3), forced vital capacity (FVC), forced expiratory volume in first second (FEV1), and maximal mid-expiratory flow (MMEF) were measured, arterial blood samples were collected for blood gas analysis, arterial carbon dioxide partial pressure and arterial oxygen partial pressure (PaO2) were recorded, and alveolar-arterial oxygen tension difference (PA-aO2)was calculated.Clinical Pulmonary Infection Score was assessed at T1, T2 and T3.The chest tube removal time and length of postoperative hospital stay were recorded. Results Compared with the baseline at T0, FVC, FEV1, MMEF and PaO2 were significantly decreased, and PA-aO2 was increased at T1-3 in the two groups (P<0.05). Compared with group V, FVC, FEV1, MMEF and PaO2 were significantly increased, PA-aO2 and Clinical Pulmonary Infection Score were decreased, and the chest tube removal time and length of postoperative hospital stay were shortened at T1-3 in group P (P<0.05). Conclusion PCV-VG mode can achieve lung protective ventilation, which is helpful in improving outcomes in the patients requiring OLV during thoracoscopic surgery. Key words: Respiration, artificial; Thoracoscopy

Comparison of volume controlled ventilation and pressure controlled ventilation in patients undergoing robot-assisted pelvic surgeries: An open-label trial.

Background and Aims:Although volume controlled ventilation (VCV) has been the traditional mode of ventilation in robotic surgery, recently pressure controlled ventilation (PCV) has been used more frequently. However, evidence on whether PCV is superior to VCV is still lacking. We intended to compare the effects of VCV and PCV on respiratory mechanics and haemodynamic in patients undergoing robotic surgeries in steep Trendelenburg position.Methods:This prospective, randomized trial was conducted on sixty patients between 20 and 70 years belonging to the American Society of Anesthesiologist Physical Status I–II. Patients were randomly assigned to VCV group (n = 30), where VCV mode was maintained through anaesthesia, or the PCV group (n = 30), where ventilation mode was changed to PCV after the establishment of 40° Trendelenburg position and pneumoperitoneum. Respiratory (peak and mean airway pressure [APpeak, APmean], dynamic lung compliance [Cdyn] and arterial blood gas analysis) and haemodynamics variables (heart rate, mean blood pressure [MBP] central venous pressure) were measured at baseline (T1), post-Trendelenburg position at 60 min (T2), 120 min (T3) and after resuming supine position (T4).Results:Demographic profile, haemodynamic variables, oxygen saturation and minute ventilation (MV) were comparable between two groups. Despite similar values of APmean, APpeak was significantly higher in VCV group at T2 and T3 as compared to PCV group (P < 0.001). Cdyn and PaCO2 were also better in PCV group than in VCV group (P < 0.001 and 0.045, respectively).Conclusion:PCV should be preferred in robotic pelvic surgeries as it offers lower airway pressures, greater Cdyn and a better-preserved ventilation-perfusion matching for the same levels of MV.

Comparison of volume control and pressure control ventilation in patients undergoing single level anterior cervical discectomy and fusion surgery.

Background and Aims:Pressure control and volume control ventilation are the most preferred modes of ventilator techniques available in the intraoperative period. The study compared the intraoperative ventilator and blood gas variables of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) in patients undergoing single level anterior cervical discectomy and fusion (ACDF).Methods:After obtaining Institutional Ethical Committee approval and informed consent, sixty patients scheduled for single level ACDF surgery performed in supine position under general anaesthesia were included. Group V (30 patients) received VCV and Group P (30 patients) received PCV. The primary objective was oxygenation variable PaO2/FiO2 at different points of time i.e. T1–20 min after the institution of the ventilation, T2–20 min after placement of the retractors and T3–20 min after removal of the retractors. The secondary objectives include other arterial blood gas parameters, respiratory and haemodynamic parameters. NCSS version 9 statistical software was used for statistics. Two-way repeated measures for analysis of variance with post hoc Tukey Kramer test was used to analyse continuous variables for both intra- and inter-group comparisons, paired sample t-test for overall comparison and Chi-square test for categorical data.Results:The primary variable PaO2/FiO2 was comparable in both groups (P = 0.08). The respiratory variables, PAP and Cdynam were statistically significant in PCV group compared to VCV (P < 0.05), though clinically insignificant. Other secondary variables were comparable. (P > 0.05)Conclusion:Clinically, both PCV and VCV group appear to be-equally suited ventilator techniques for anterior cervical spine surgery patients.

The role of ventilation mode using a laryngeal mask airway during gynecological laparoscopy on lung mechanics, hemodynamic response and blood gas analysis

There are two methods for ventilation in gynecological laparoscopy: volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). To compare the lung mechanics, hemodynamic response and arterial blood gas analysis and gas exchange of two modes of VCV and PCV using laryngeal mask airway (LMA) at different time intervals. Sixty infertile women referred for diagnostic laparoscopy, based on ventilation mode, were randomly divided into two groups of VCV (tidal volume: 10 ml/kg) and PCV. In the PCV group, ventilation was initiated with a peak airway pressure (tidal volume: 10 ml/kg, upper limit: 35 cm H2O). In both groups, the arterial blood samples were taken in several time intervals (5, 10 and 15 min after LMA insertion) for blood gas evaluation. Also the lung mechanics parameters were continuously monitored and were recorded at different time intervals. There were no significant differences for patient's age, weight, height and BMI in two groups. The peak and plateau airway pressure were significantly higher in VCV group compared to PCV group 5 and 10 min after insertion of LMA. PaO2 was significantly higher after 10 and 15 min in VCV group compared to PCV group (p=0.005 and p=0.03, respectively). PaCO2 showed significant increase after 5 min in PCV group, but the differences were not significant after 10 and 15 min in two groups. The end tidal CO2 showed significant increase after 10 and 15 min in VCV compared to PCV group. Both VCV and PCV seem to be suitable for gynecological laparoscopy. However, airway pressures are significantly lower in PCV compared to VCV.

Effect of Mechanical Ventilation Mode Type on Intra- and Postoperative Blood Loss in Patients Undergoing Posterior Lumbar Interbody Fusion Surgery: A Randomized Controlled Trial.

The aim of study was to evaluate the effect of mechanical ventilation mode type, pressure-controlled ventilation (PCV), or volume-controlled ventilation (VCV) on intra- and postoperative surgical bleeding in patients undergoing posterior lumbar interbody fusion (PLIF) surgery. This was a prospective, randomized, single-blinded, and parallel study that included 56 patients undergoing PLIF and who were mechanically ventilated using PCV or VCV. A permuted block randomization was used with a computer-generated list. The hemodynamic and respiratory parameters were measured after anesthesia induction in supine position, 5 min after patients were changed from supine to prone position, at the time of skin closure, and 5 min after the patients were changed from prone to supine position. The amount of intraoperative surgical bleeding, fluid administration, urine output, and transfusion requirement were measured at the end of surgery. The amount of postoperative bleeding and transfusion requirement were recorded every 24 h for 72 h. The primary outcome was the amount of intraoperative surgical bleeding, and 56 patients were analyzed. The amount of intraoperative surgical bleeding was significantly less in the PCV group than that in the VCV group (median, 253.0 [interquartile range, 179.0 to 316.5] ml in PCV group vs. 382.5 [328.0 to 489.5] ml in VCV group; P < 0.001). Comparing other parameters between groups, only peak inspiratory pressure at each measurement point in PCV group was significantly lower than that in VCV group. No harmful events were recorded. Intraoperative PCV decreased intraoperative surgical bleeding in patients undergoing PLIF, which may be related to lower intraoperative peak inspiratory pressure.