Pressure-controlled Ventilation-volume Guaranteed Research Articles

Lung ultrasound score evaluation of the effect of pressure-controlled ventilation volume-guaranteed on patients undergoing laparoscopic-assisted radical gastrectomy.

Laparoscopic-assisted radical gastrectomy (LARG) is the standard treatment for early-stage gastric carcinoma (GC). However, the negative impact of this procedure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation. To investigate the influence of pressure-controlled ventilation volume-guaranteed (PCV-VG) and volume-controlled ventilation (VCV) on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score (LUS). The study included 103 patients with GC undergoing LARG from May 2020 to May 2023, with 52 cases undergoing PCV-VG (research group) and 51 cases undergoing VCV (control group). LUS were recorded at the time of entering the operating room (T0), 20 minutes after anesthesia with endotracheal intubation (T1), 30 minutes after artificial pneumoperitoneum (PP) establishment (T2), and 15 minutes after endotracheal tube removal (T5). For blood gas analysis, arterial partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were observed. Peak airway pressure (Ppeak), plateau pressure (Pplat), mean airway pressure (Pmean), and dynamic pulmonary compliance (Cdyn) were recorded at T1 and T2, 1 hour after PP establishment (T3), and at the end of the operation (T4). Postoperative pulmonary complications (PPCs) were recorded. Pre- and postoperative serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay. Compared with those at T0, the whole, anterior, lateral, posterior, upper, lower, left, and right lung LUS of the research group were significantly reduced at T1, T2, and T5; in the control group, the LUS of the whole and partial lung regions (posterior, lower, and right lung) decreased significantly at T2, while at T5, the LUS of the whole and some regions (lateral, lower, and left lung) increased significantly. In comparison with the control group, the whole and regional LUS of the research group were reduced at T1, T2, and T5, with an increase in PaO2, decrease in PaCO2, reduction in Ppeak at T1 to T4, increase in Pmean and Cdyn, and decrease in Pplat at T4, all significant. The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively. Postoperative IL-1β, IL-6, and TNF-α significantly increased in both groups, with even higher levels in the control group. LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV. Under the lung protective ventilation strategy, the PCV-VG mode more significantly improved intraoperative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production, thereby alleviating lung injury.

Comparison of volume-controlled ventilation, pressure-controlled ventilation and pressure-controlled ventilation-volume guaranteed in infants and young children in the prone position: A prospective randomized study

Study objectiveTo explore if the pressure-controlled ventilation (PCV) and pressure-controlled ventilation-volume guaranteed (PCV-VG) modes are superior to volume-controlled ventilation (VCV) in optimizing intraoperative respiratory mechanics in infants and young children in the prone position. DesignA single-center prospective randomized study. SettingChildren's Hospital, Zhejiang University School of Medicine. PatientsPediatric patients aged 1 month to 3 years undergoing elective spinal cord detethering surgery. InterventionsPatients were randomly allocated to the VCV group, PCV group and PCV-VG group. The target tidal volume (VT) was 8 mL/kg and the respiratory rate (RR) was adjusted to maintain a constant end tidal CO2. MeasurementsThe primary outcome was intraoperative peak airway pressure (Ppeak). Secondary outcomes included other respiratory and ventilation variables, gas exchange values, serum lung injury biomarkers concentration, hemodynamic parameters and postoperative respiratory complications. Main resultsA total of 120 patients were included in the final analysis (40 in each group). The VCV group showed higher Ppeak at T2 (10 min after prone positioning) and T3 (30 min after prone positioning) than the PCV and PCV-VG groups (T2: P = 0.015 and P = 0.002, respectively; T3: P = 0.007 and P = 0.009, respectively). The prone-related decrease in dynamic compliance was prevented by PCV and PCV-VG ventilation modalities at T2 and T3 than by VCV (T2: P = 0.008 and P = 0.015, respectively; T3: P = 0.015 and P = 0.014, respectively). Additionally, there were no significant differences in other secondary outcomes among the three groups. ConclusionIn infants and young children undergoing spinal cord detethering surgery in the prone position, PCV-VG may be a better ventilation mode due to its ability to mitigate the increase in Ppeak and decrease in Cdyn while maintaining consistent VT.

Pressure-controlled ventilation-volume guaranteed mode improves bronchial mucus transport velocity in patients during laparoscopic surgery for gynecological oncology: a randomized controlled study

BackgroundMechanical ventilation during general anesthesia may impair airway mucosal function. This study aimed to investigate the effect of pressure-controlled ventilation-volume guaranteed (PCV-VG) on bronchial mucus transport velocity (BTV) in patients during laparoscopic surgery for gynecological oncology compared with volume controlled ventilation (VCV).Methods66 patients undergoing elective a laparoscopic surgery for gynecological oncology. The patients were randomized into two group receiving either PCV-VG or VCV. a drop of methylene blue was placed on the surface of the airway mucosa under the bronchoscopeand, then the distance the dye movement was measured after 2, 4, and 6 min. Outcomes were assessed at T0 (5 min after endotracheal intubation and before initiation of pneumoperitoneum), T1 and T2 (1 and 2 h after stabilization of pneumoperitoneum respectively). BTV at T0, T1 and T2 was the primary outcome. Secondary outcomes included heart rate (HR), mean arterial pressure (MAP), body temperature, end-tidal CO2 pressure (PETCO2), tidal volume(VT), peak inspiratory pressure (PIP), mean inspiratory pressure (Pmean), respiratory rate (RR), and dynamic compliance (CDyn) at T0, T1, and T2.Results64 patients were included in the analysis. The median [interquartile range] BTV was significantly lower in VCV group at T1 and T2 that at T0 (P < 0.05). Furthermore, BTV was slightly reduced in PCV-VG compared with VCV. BTV in PCV-VG was significantly decreased at T2 compared with BTV at T0 (P < 0.05) and slightly decreased at T1 compared with T0(P > 0.05). Compared with the PCV-VG group, BTV in VCV group significantly decreased at T2 (P < 0.05). No participants experienced respiratory complications.ConclusionsPCV-VG is more suitable for patients undergoing laparoscopic surgery for gynecological oncology than VCV since it can protect mucociliary clearance function.Trial registrationThis trial is registered on https://www.chictr.org.cn/ in Chinese Clinical Trial Registry (ChiCTR.2200064564: Date of registration 11/10/2022).

Effect of pressure-controlled ventilation-volume guaranteed mode combined with individualized positive end-expiratory pressure on respiratory mechanics, oxygenation and lung injury in patients undergoing laparoscopic surgery in Trendelenburg position

The study aimed to investigate the efficacy of PCV-VG combined with individual PEEP during laparoscopic surgery in the Trendelenburg position. 120 patients were randomly divided into four groups: VF group (VCV plus 5cmH2O PEEP), PF group (PCV-VG plus 5cmH2O PEEP), VI group (VCV plus individual PEEP), and PI group (PCV-VG plus individual PEEP). Pmean, Ppeak, Cdyn, PaO2/FiO2, VD/VT, A-aDO2 and Qs/Qt were recorded at T1 (15 min after the induction of anesthesia), T2 (60 min after pneumoperitoneum), and T3 (5 min at the end of anesthesia). The CC16 and IL-6 were measured at T1 and T3. Our results showed that the Pmean was increased in VI and PI group, and the Ppeak was lower in PI group at T2. At T2 and T3, the Cdyn of PI group was higher than that in other groups, and PaO2/FiO2 was increased in PI group compared with VF and VI group. At T2 and T3, A-aDO2 of PI and PF group was reduced than that in other groups. The Qs/Qt was decreased in PI group compared with VF and VI group at T2 and T3. At T2, VD/VT in PI group was decreased than other groups. At T3, the concentration of CC16 in PI group was lower compared with other groups, and IL-6 level of PI group was decreased than that in VF and VI group. In conclusion, the patients who underwent laparoscopic surgery, PCV-VG combined with individual PEEP produced favorable lung mechanics and oxygenation, and thus reducing inflammatory response and lung injury.Clinical Trial registry: chictr.org. identifier: ChiCTR-2100044928

Use of volume controlled vs. pressure controlled volume guaranteed ventilation in elderly patients undergoing laparoscopic surgery with laryngeal mask airway

BackgroundThe peak inspiratory pressure (PIP) is crucial in mechanical ventilation with supraglottic airway device (SAD). Pressure-controlled ventilation volume-guaranteed (PCV-VG), delivering a preset tidal volume with the lowest required airway pressure, is being increasingly used during general anesthesia. In this study, we compared respiratory mechanics and circulatory parameters between volume-controlled ventilation (VCV) and PCV-VG in elderly patients undergoing laparoscopic surgery using the laryngeal mask airway supreme (LMA).MethodsEighty participants scheduled for laparoscopic surgery were enrolled in this prospective, randomized clinical trial. The participants were randomly assigned to receive VCV or PCV-VG. PIP, dynamic compliance (Cdyn) and mean inspiratory pressure (Pmean) were recorded at 5 min after induction of anesthesia (T1), 5 min after pneumoperitoneum(T2), 30 and 60 min after pneumoperitoneum (T3 and T4). Data including other respiratory variables, hemodynamic variables, and arterial blood gases were also collected. The difference in PIP between VCV and PCV-VG was assessed as the primary outcome.ResultsPIP was significantly lower at T2, T3, and T4 in both groups compared with T1 (all P < 0.0001), and it was significantly lower in the PCV-VG group than the VCV group at T2, T3, and T4 (all P < 0.001). Cydn was decreased at T2, T3, and T4 in two groups compared with T1 (all P < 0.0001), but it was higher in PCV-VG group than in VCV group at T2, T3, and T4 (all P < 0.0001). There were on statistically significant differences were found between the groups for other respiratory and hemodynamic variables.ConclusionIn elderly patients who underwent laparoscopic surgery using an LMA, PCV-VG was superior to VCV in its ability to provide ventilation with lower peak inspiratory pressure and greater dynamic compliance.

COMPARATIVE STUDY BETWEEN THE EFFECT OF VOLUME-CONTROLLED VENTILATION AND PRESSURE CONTROLLED VENTILATION VOLUME GUARANTEED ON GAS EXCHANGE AND RESPIRATORY DYNAMICS DURING ONE-LUNG VENTILATION

ABSTRACT Background: Impairment of gas exchange is a common problem during one lung ventilation (OLV) with a hazardous effect on morbidity and mortality. The current study compares the effect of volume-controlled ventilation (VCV) versus pressure-controlled ventilation volume guaranteed (PCV-VG) on gas exchange during OLV. Settings and Design: This study was a prospective randomized study. Methods: The study was carried out on 30 adult patients who were randomly assigned to two groups. Group VCV: VCV was performed throughout the operation. Group PCV-VG: PCV-VG was performed throughout the operation. Haemodynamic parameters ((HR), MAP), and (CVP)), blood gas analysis, and PaO2/FiO2 were recorded: before induction of anaesthesia (T0); during TLV (T1); ½ an hour after OLV (T2); 1 h after OLV (T3); 20 minutes after resuming TLV (T4); 6, 12, and 24 hours after surgery (T5, 6, and T7). (Ppeak), (Pmean) and (Cdyn) were recorded during (T1, 2, 3, and T4) time intervals. TNFα level was measured in venous Samples in the following times: (1) before induction of anaesthesia (T0); (2) Directly after surgery (T1); (3) 5th postoperative day (T2). The patients were followed for 5 days for recording of PPCs. Results: PCV-VG ventilation leads to a significant decrease in Ppeak and Pmean and significant increase in Cdyn (P ≤ 0.05). However, it had no effect on intra- and postoperative oxygenation values. Conclusion: PCV-VG is superior to VCV as regard respiratory dynamics during one lung ventilation (OLV), while it does not differ as regard items of gas exchange, inflammatory response and PPCs. Abbreviations: OLV: one lung ventilation; TLV: two lung ventilation; VCV: volume-controlled ventilation; PCV-VG: pressure-controlled ventilation volume guaranteed; PaO2: arterial oxygen tension; FiO2: fraction of inspired oxygen; Ppeak: Peak inspiratory pressure; Pmean: mean inspiratory pressure; Cdyn: dynamic compliance TNFα: Tumour necrosis factor α; PPCs: postoperative pulmonary complications.

Assessment of Perioperative Atelectasis Using Lung Ultrasonography in Patients Undergoing Pneumoperitoneum Surgery in the Trendelenburg Position: Aspects of Differences according to Ventilatory Mode.

BackgroundDuring robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position, aeration loss leads to perioperative atelectasis. Recently developed ventilator mode pressure-controlled ventilation volume-guaranteed (PCV-VG) mode could provide adequate ventilation with lower inspiratory pressure compared to volume-controlled ventilation (VCV); we hypothesized that PCV-VG mode may be beneficial in reducing perioperative atelectasis via low tidal volume (VT) of 6 mL/kg ventilation during robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position. We applied lung ultrasound score (LUS) for detecting perioperative atelectasis. We aimed to compare perioperative atelectasis between VCV and PCV-VG with a low VT of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position using LUS.MethodsPatients scheduled for robotic gynecologic surgery were randomly allocated to the VCV (n = 41) or PCV-VG group (n = 41). LUS, ventilatory, and hemodynamic parameters were evaluated at T1 (before induction), T2 (10 minutes after induction in the supine position), T3 (10 minutes after desufflation of CO2 in the supine position), and T4 (30 minutes after emergence from anesthesia in the recovery room).ResultsEighty patients (40 with PCV-VG and 40 with VCV) were included. Demographic data showed no significant differences between the groups. The total LUS has changed from baseline to T4, 0.63 (95% confidence interval [CI], 0.32, 0.94) to 1.77 (95% CI, 1.42, 2.21) in the VCV group and 0.86 (95% CI, 0.56, 1.16) to 1.43 (95% CI, 1.08, 1.78) in the PCV-VG group (P = 0.170). In both groups, total LUS increased significantly compared to the baseline values.ConclusionUsing a low VT of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position, our study showed no evidence that PCV-VG ventilation was superior to VCV in terms of perioperative atelectasis.Trial RegistrationClinical Research Information Service Identifier: KCT0006404

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.

Effects of small tidal volume and positive end-expiratory pressure on oxygenation in pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation

Introduction The purpose of this study was to investigate whether tidal volume (TV) of 8 mL/kg without positive end-expiratory pressure (PEEP) and TV of 6 mL/kg with or without PEEP in pressure-controlled, ventilation-volume guaranteed (PCV-VG) mode can maintain arterial oxygenation and decrease inspiratory airway pressure effectively during one-lung ventilation (OLV). Methods The study enrolled 27 patients undergoing thoracic surgery. All patients were ventilated with PCV-VG mode. During OLV, patients were initially ventilated with TV 8 mL/kg (group TV8) without PEEP. Ventilation was subsequently changed to TV 6 mL/kg with PEEP (5 cmH2O; group TV6+PEEP) or without (group TV6) in random sequence. Peak inspiratory pressure (Ppeak), mean airway pressure (Pmean), and arterial blood gas analysis were measured 30 min after changing ventilator settings. Ventilation was then changed once more to add or eliminate PEEP (5 cmH2O), while maintaining TV 6 mL/kg. Thirty min after changing ventilator settings, the same parameters were measured once more. Results The Ppeak was significantly lower in group TV6 (19.3±3.3 cmH2O) than in group TV8 (21.8±3.1 cmH2O) and group TV6+PEEP (20.1±3.4 cmH2O). PaO2 was significantly higher in group TV8 (242.5±111.4 mmHg) than in group TV6 (202.1±101.3 mmHg) (P = 0.044). There was no significant difference in PaO2 between group TV8 and group TV6+PEEP (226.8±121.1 mmHg). However, three patients in group TV6 were dropped from the study because PaO2 was lower than 80 mmHg after ventilation. Discussion It is postulated that TV 8 mL/kg without PEEP or TV 6 mL/kg with 5 cmH2O PEEP in PCV-VG mode during OLV can safely maintain adequate oxygenation.

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 small tidal volume and positive end-expiratory pressure on oxygenation in pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation.

BackgroundThe purpose of this study was to investigate whether tidal volume (TV) of 8 mL/kg without positive end-expiratory pressure (PEEP) and TV of 6 mL/kg with or without PEEP in pressure-controlled ventilation-volume guaranteed (PCV-VG) mode can maintain arterial oxygenation and decrease inspiratory airway pressure effectively during one-lung ventilation (OLV).MethodsThe study enrolled 27 patients undergoing thoracic surgery. All patients were ventilated with PCV-VG mode. During OLV, patients were initially ventilated with TV 8 mL/kg (group TV8) without PEEP. Ventilation was subsequently changed to TV 6 mL/kg with PEEP (5 cmH2O; group TV6+PEEP) or without (group TV6) in random sequence. Peak inspiratory pressure (Ppeak), mean airway pressure (Pmean), and arterial blood gas analysis were measured 30 min after changing ventilator settings. Ventilation was then changed once more to add or eliminate PEEP (5 cmH2O), while maintaining TV 6 mL/kg. Thirty min after changing ventilator settings, the same parameters were measured once more.ResultsThe Ppeak was significantly lower in group TV6 (19.3±3.3 cmH2O) than in group TV8 (21.8±3.1 cmH2O) and group TV6+PEEP (20.1±3.4 cmH2O). PaO2 was significantly higher in group TV8 (242.5±111.4 mmHg) than in group TV6 (202.1±101.3 mmHg) (p=0.044). There was no significant difference in PaO2 between group TV8 and group TV6+PEEP (226.8±121.1 mmHg). However, three patients in group TV6 were dropped from the study because PaO2 was lower than 80 mmHg after ventilation.ConclusionIt is postulated that TV 8 mL/kg without PEEP or TV 6 mL/kg with 5 cmH2O PEEP in PCV-VG mode during OLV can safely maintain adequate oxygenation.

Effect of pressure-controlled ventilation-volume guaranteed mode on respiratory mechanics in gynecologic laparoscopic surgery

Objective To explore the effects of pressure-controlled ventilation-volume guaranteed(PCV-VG) mode on hemodynamics, blood gas analysis and respiratory mechanics in patients undergoing gynecologic laparoscopic surgery, compared with volume-controlled ventilation(VCV) mode. Methods Forty patients undergoing gynecologic laparoscopic surgery were randomly allocated into 2 groups(n=20): group PCV-VG and group VCV. The HR, MAP were recorded before induction of anesthesia without oxygen inhalation (T0), 10 min after tracheal intubation (T1), 40 min after pneumoperitoneum in trendelenburg position (T2), 5 min after closing pneumoperitoneum in supine position(T3) and 5 min after extubation(T4). PaO2, PaCO2, the peak airway pressure (Ppeak), plateau pressure (Pplat) and thoracic compliance (Cdyn) were measured at T1, T2, T3. Results The PaO2 at T2 was significantly lower than that at T1 and T3 in both groups (P 0.05). There were higher Ppeak and Pplat and lower Cdyn at T2 than those at T1 and T3 in both groups (P 0.05). Conclusions In comparison with VCV, PCV-VG can effectively enhance thoracic compliance, lower the airway peak pressure and plateau pressure, improve arterial oxygenation and gas exchange, and decrease the risk of lung injury after mechanical ventilation in patients undergoing gynecologic laparoscopic surgery. Key words: Volume-controlled ventilation; Pressure-controlled ventilation-volume guaranteed; Gynecologic laparoscopic surgery; Respiratory mechanics

Lung-protective effect of lung-protective ventilation combined with pressure-controlled ventilation-volume guaranteed in elderly patients undergoing one-lung ventilation

Objective To evaluate the lung-protective effect of lung-protective ventilation(LPV)combined with ventilatory mode pressure-controlled ventilation-volume guaranteed(PCV-VG)in elderly patients undergoing one-lung ventilation(OLV). Methods Eighty American Society of Anesthesiologists physical statusⅠ-Ⅲ patients, aged 65-80 yr, with body mass index of 15-28 kg/m2, scheduled for elective radical resection for esophageal cancer performed via video-assisted thoracoscope, were divided into 4 groups(n=20 each)using a random number table: control group(group C), PCV-VG group, LPV group and LPV combined with PCV-VG group(group LPV+ PCV-VG). At 20 min after changing the body position during two-lung ventilation(T1), 30 min of OLV(T2)and 20 min after restoration of two-lung ventilation(T3), blood samples were collected from the radial artery for blood gas analysis and for determination of peak airway pressure(Ppeak), mean airway pressure(Pmean)and dynamic lung compliance(Cdyn). Alveolar-arterial oxygen gradient, intrapulmonary shunt(Qs/Qt), dead space fraction(Vd/VT)and respiratory index were calculated at T2.Blood samples were collected from the radial artery before induction of anesthesia and at the end of operation for determination of plasma neutrophil elastase(NE)concentrations by enzyme-linked immunosorbent assay.The Clinical Pulmonary Infection Score(CPIS)was assessed at 1 and 7 days after operation, and the development of pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection was recorded within 7 days after operation. Results Compared with group C, Ppeak was significantly decreased, and Pmean was increased in group PCV-VG, Ppeak and PaCO2 were significantly increased and pH value, Vd/VT and Qs/Qt were decreased in group LPV, Ppeak, Vd/VT, Qs/Qt, pH value and postoperative CPIS were significantly decreased, and Pmean, Cdyn and PaO2 were increased in group LPV+ PCV-VG, and the NE concentration at the end of operation was significantly decreased in PCV-VG, LPV and LPV+ PCV-VG groups(P<0.05). Compared with group PCV-VG, Pmean, Cdyn and PaO2 were significantly increased, and pH value, Qs/Qt, NE concentration at the end of operation and CPIS were decreased in group LPV+ PCV-VG(P<0.05). Compared with group LPV, Ppeak, Qs/Qt, NE concentration at the end of operation and CPIS were significantly decreased, and Cdyn was increased in group LPV+ PCV-VG(P<0.05). Pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection were not observed after operation in the four groups. Conclusion LPV combined with PCV-VG can optimize the lung-protective effect in elderly patients undergoing OLV. Key words: Respiration, artificial; Aged

Comparison of volume-controlled ventilation and pressure-controlled ventilation volume guaranteed during laparoscopic surgery in Trendelenburg position

Study objectiveTo analyze the effects of pressure-controlled ventilation-volume guaranteed (PCV-VG) and volume controlled ventilation (VCV) on airway pressures and respiratory and circulatory indicators during laparoscopic surgery in Trendelenburg position. DesignProspective randomized comparative clinical study. SettingTertiary hospital. PatientsForty ASA physical status 1 and 2 patients who underwent elective laparoscopic surgery in Trendelenburg position. InterventionsPatients were randomly allocated to either VCV group (n=20) or the PCV-VG group (n=20). After induction of anesthesia, for both modes of ventilation, the target tidal volume (VT) was 8mL/kg and the respiratory rate was adjusted to avoid hypercarbia. MeasurementsThe peak and mean inspiratory pressures, dynamic compliance, exhaled VT, oxygenation index and physiological dead space were calculated and recorded at T1, 5minutes after induction of anesthesia in supine position, T2, 5minutes after stabilization of pneumoperitoneum, T3 and T4, 15 and 60minutes after 30° Trendelenburg position with pneumoperitoneum respectively. Main resultsPCV-VG group had significantly lower peak inspiratory pressure and greater dynamic compliance than VCV group (P<.001). ConclusionsIn patients who underwent laparoscopic surgery in Trendelenburg position, PCV-VG was superior to VCV in its ability to provide ventilation with lower peak inspiratory pressure and greater dynamic compliance.

The dual mode of ventilation ′pressure-controlled ventilation-volume guaranteed′ does not provide anymore benefit in obese anesthetized patients

Background Ventilatory strategies aim at the prevention of atelectasis and the improvement of oxygenation, but yet none is optimal. On comparing pressure-controlled ventilation (PCV) with volume-controlled ventilation (VCV) with the same tidal volume and inspiratory time, PCV tends to produce higher mean airway pressures, and thereby improves oxygenation. However, volume-targeted ventilators (VTV) allow to set the tidal volume directly. In order to deliver that volume. We compared PCV and pressure-controlled ventilation volume guaranteed (PCV-VG) with regard to the airway pressures produced when aiming to achieve the same tidal volume. Patients and methods Thirty obese ASA I-III patients scheduled for abdominal surgery were ventilated with PCV for 45 min; then, the PCV-VG mode was applied to all patients with the same parameters, targeting the same tidal volume of conventional PCV during the first phase. The plateau pressure and the mean airway pressure were recorded and compared between both modes. Vital signs, EtCO 2 , SpO 2 , arterial blood gases, and the oxygenation index were compared. Results No difference was observed between both modes of ventilation in terms of the plateau airway pressure (34.2 ΁ 1.8 vs. 34.1 ΁ 2.9 cmH 2 O, P = 0.484) and the mean airway pressure (13.4 ΁ 1.6 vs. 13.2 ΁ 1.8 cmH 2 O, P = 0.326). No significant difference was observed between PCV and PCV-VG with regard to the hemodynamics, EtCO 2 , and SpO 2 . No significant change was observed in the arterial blood gas analysis including pH (7.39 ΁ 0.3 versus 7.4 ΁ 0.2 with P value 0.204), PaCO 2 (30.8e 0.204) change in 0.2 with P value 0.06), PaO 2 (155.8 0.06)) change in0.2 with blood P value 0.316) and oxygenation index (4.34 oxygenation index.2 with bP value 0.176). ConclusionNo significant difference was observed between both modes of ventilation (PCV vs. PCV-VG) in obese patients.

Volume-controlled versus pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation.

BackgroundThe purpose of this study was to investigate the changes in airway pressure and arterial oxygenation between ventilation modes during one-lung ventilation (OLV) in patients undergoing thoracic surgery.MethodsWe enrolled 27 patients for thoracic surgery with OLV in the lateral decubitus position. The subjects received various modes of ventilation in random sequences during surgery, including volume-controlled ventilation (VCV) and pressure-controlled ventilation-volume guaranteed (PCV-VG) with a tidal volume (TV) of 8 ml/kg of actual body weight. Target-controlled infusion (TCI) with propofol and remifentanil was used for anesthesia induction and maintenance. After double-lumen endobronchial tube (DLT) insertion, the proper positioning of the DLT was assessed using a fiberoptic bronchoscope. Peak inspiratory pressure (Ppeak), exhaled TV, and arterial blood gas were measured 30 min after each ventilation mode.ResultsPpeak was significantly reduced with the PCV-VG mode (19.6 ± 2.5 cmH2O) compared with the VCV mode (23.2 ± 3.1 cmH2O) (P < 0.000). However, no difference in arterial oxygen tension was noted between the groups (PCV-VG, 375.8 ± 145.1 mmHg; VCV, 328.1 ± 123.7 mmHg) (P = 0.063). The exhaled TV was also significantly increased in PCV-VG compared with VCV (451.4 ± 85.4 vs. 443.9 ± 85.9 ml; P = 0.035).ConclusionsDuring OLV in patients with normal lung function, although PCV-VG did not provide significantly improved arterial oxygen tension compared with VCV, PCV-VG provided significantly attenuated airway pressure despite significantly increased exhaled TV compared with VCV.

Does pressure-controlled ventilation-volume guaranteed differ from pressure-controlled ventilation in anesthetized patients

Background General anesthesia causes depression of both respiratory centers and respiratory muscles. Hence, patients under general anesthesia require ventilatory support to maintain arterial oxygenation and eliminate carbon dioxide. Mechanical ventilation can improve patients outcome. The purpose of this study was to determine whether pressure-controlled ventilation-volume guaranteed (PCV-VG) provide better oxygenation than pressure-controlled ventilation (PCV) in anesthetized patients. Patients and methods A total of 30 patients scheduled for abdominal cancer surgery under general anesthesia were enrolled in the study. Mechanical ventilation was started with PCV for 60 min then PCV-VG was applied to all patients with the same parameters, targeting the obtained tidal volume (Vt). Arterial blood pressures, heart rate, ETCO 2 , SpO 2 , pH, PaCO 2 , and PaO 2 were measured after 60 min of intubation during PCV and after 60 min of initiation of PCV-VG. Vt, mean airway pressure, and peak airway pressure (during PCV-VG) were recorded. Oxygenation index calculation was performed at the preset times. Results All parameters were comparable with no significant difference between both modes of ventilation in anesthetized patients ( P ≥ 0.05). Conclusion While maintaining constant Vt and I/E ratio, there were no significant differences in respiratory and ventilatory parameters, and also the oxygenation index was comparable between both PCV and PCV-VG modes of ventilation.

Efficiency of the newly introduced ventilatory mode “pressure controlled ventilation-volume guaranteed” in thoracic surgery with one lung ventilation

BackgroundAnesthesia for thoracic surgery routinely involves one lung ventilation (OLV). Volume controlled ventilation (VCV) was and still the most common method of performing OLV. We assumed that pressure controlled ventilation-volume guaranteed (PCV-VG) is a better ventilation strategy for OLV than VCV as regard the inspiratory pressures, oxygenation parameters and post-operative ventilatory outcome.MethodsForty patients undergoing elective thoracic surgery in the lateral position requiring at least 1 h of OLV were randomly assigned into two groups. Group VCV: VCV was performed throughout the operation. Group PCV-VG: PCV-VG was performed throughout the operation. Blood gas analysis, peak inspiratory pressure (Ppeak), mean inspiratory pressure (Pmean), plateau inspiratory pressure (Pplateau) were measured: (1) During two lung ventilation (TLV1) 30 min after turning the patient to the lateral decubitus prior the beginning of OLV; (2) 30 min after initiation of OLV(OLV); (3) End of surgery: 30 min after reestablishing TLV (TLV2).ResultsThe Ppeak and the Pplateau were significantly lower in PCV-VG compared with VCV in all stages of the study (P value < 0.05). There was significant increase in all pressure values in OLV compared with TLV1 in the two groups (P value < 0.05). There were significant decrease in the mean Pao2 values during OLV and TLV2 compared with TLV1 in the two groups (P value < 0.05). Yet the Pao2 was significantly higher in the PCV-VG group at OLV and TLV2 compared to the OLV and TLV2 in VCV group. Also Pao2 was significantly lower in TLV2 compared with TLV1 in both groups (P value < 0.05).ConclusionIn patients undergoing thoracic surgery with OLV, pressure controlled volume guaranteed mode of ventilation decreases inspiratory pressure parameters and improve arterial oxygenation better than volume controlled ventilation.