Pressure-controlled Ventilation Group Research Articles

How to Prevent Ventilator-Induced Lung Injury in Intraoperative Mechanical Ventilation? A Randomized Prospective Study.

Intraoperative mechanical ventilation practices can lead to ventilator-induced lung injury (VILI) and postoperative pulmonary complications in healthy lungs. Mechanical power (MP) has been developed as a new concept in reducing the risk of postoperative pulmonary complications as it considers all respiratory mechanics that cause VILI. The most commonly used intraoperative modes are volume control ventilation (VCV) and pressure control ventilation (PCV). In this study, VCV and PCV modes were compared in terms of respiratory mechanics in patients operated in the supine and prone positions. The patients were divided into 4 groups (80 patients), volume control supine and prone, pressure control supine and prone with 20 patients each. MP, respiratory rate, positive end-expiratory pressure, tidal volume, peak pressure, plato pressure, driving pressure, inspiratory time, height, age, gender, body mass index, and predictive body weight data of the patients included in the groups have been obtained from "electronic data pool" with Structured Query Language queries. The supine and prone MP values of the VCV group were statistically significantly lower than the PCV group (P values were 0.010 and 0.001, respectively). Supine and prone MP values of the VCV group were calculated significantly lower than the PCV group. Intraoperative PCV may be considered disadvantageous regarding the risk of VILI in the supine and prone positions.

Nocturnal Pressure Controlled Ventilation Improves Sleep Efficiency in Patients Receiving Mechanical Ventilation.

Patients receiving mechanical ventilation commonly experience sleep fragmentation. The present meta-analysis compared the effects of pressure controlled ventilation (PCV) and pressure support ventilation (PSV) on sleep quality. We conducted a search of the PubMed, Embase, and Cochrane Library databases for studies published before November 2023. In this meta-analysis, individual effect sizes were standardized, and the pooled effect size was determined by using random-effects models. The primary outcome was sleep efficiency. The secondary outcomes were wakefulness, percentages of REM (rapid eye movement) sleep and stages 3 and 4 non-REM sleep, the fragmentation index, and the incidence of apneic events. This meta-analysis examined 4 trials that involved 67 subjects. Sleep efficiency was significantly higher in the PCV group than in the PSV group (mean difference 15.57%, 95% CI 8.54%-22.59%). Wakefulness was significantly lower in the PCV group than in the PSV group (mean difference -18.67%, 95% CI -30.29% to -7.04%). The percentage of REM sleep was significantly higher in the PCV group than in the PSV group (mean difference 2.32%, 95% CI 0.20%-4.45%). Among the subjects with a tendency to develop sleep apnea, the fragmentation index was significantly lower in those receiving PCV than PSV (mean difference -40.00%, 95% CI -51.12% to -28.88%). The incidence of apneic events was significantly lower in the PCV group than in the PSV group (risk ratio 0.06, 95% CI 0.01-0.45). Compared with PSV, PCV may improve sleep quality in patients receiving nocturnal mechanical ventilation.

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 versus Volumecontrolled Ventilation during One Lung Ventilation for Empyema Thoracis: A Randomised Control Trial

Pressure-controlled versus Volumecontrolled Ventilation during One Lung Ventilation for Empyema Thoracis: A Randomised Control Trial

Comparative study of ventilation techniques with supraglottic airway devices in cats: volume-controlled vs pressure-controlled techniques.

This study compared the effectiveness of a new supraglottic airway device (SGAD) in cats undergoing anaesthesia using two types of mechanical ventilation: volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). A total of 13 healthy cats (five male, eight female; median age 2 years [range 1-3]) were randomly allocated to either VCV or PCV. Five tidal volumes (6, 8, 10, 12 and 14 ml/kg) and five peak inspiratory pressures (4, 5, 6, 7 and 8 cmH2O) were randomly applied with a minute ventilation of 100 ml/kg/min. Various parameters, such as blood pressure, gas leakage, end-tidal CO2 (ETCO2) and work of breathing (WOB), were measured while using VCV or PCV. The occurrence of hypotension (mean arterial blood pressure <60 mmHg) was slightly less frequent with VCV (38 events, 65 ventilating sessions) than with PCV (40 events, 65 ventilating sessions), but this difference did not reach statistical significance (P = 0.429). The number of leakages did not differ between the VCV group (3 events, 65 ventilating sessions) and the PCV group (3 events, 65 ventilating sessions) (P = 1.000). Hypercapnia was identified when using VCV (10 events, 65 ventilating sessions) less frequently than when using PCV (17 events, 65 ventilating sessions), but this difference did not reach statistical significance (P = 0.194). The study found a significantly higher WOB in the PCV group compared with the VCV group (P <0.034). The present results suggested that both VCV and PCV can be used with an SGAD during anaesthesia, with VCV preferred for prolonged mechanical ventilation due to its lower workload. Adjusting tidal volume or inspiratory pressure corrects hypercapnia.

Clinical evaluation of ventilation mode on acute exacerbation of chronic obstructive pulmonary disease with respiratory failure.

At present, understanding of the most effective ventilation methods for treating chronic obstructive pulmonary disease (COPD) patients experiencing acute worsening symptoms and respiratory failure remains relatively limited. This report analyzed the efficiency and side effects of various ventilation techniques used for individuals experiencing an acute COPD exacerbation. To determine whether pressure-controlled ventilation (PCV) can lower peak airway pressures (PAPs) and reduce the incidence of barotrauma compared to volume-controlled ventilation (VCV), without compromising clinical outcomes and oxygenation parameters. We have evaluated 600 patients who were hospitalized due to a severe COPD exacerbation, with 400 receiving mechanical ventilation for the respiratory failure. The participants were divided into two different groups, who were administered either VCV or PCV, along with appropriate management. We thereafter observed patients' attributes, clinical factors, and laboratory, radiographic, and arterial blood gas evaluations at the start and during their stay in the intensive care unit (ICU). We have also employed appropriate statistical methods for the data analysis. Both the VCV and PCV groups experienced significant enhancements in the respiratory rate, tidal volume, and arterial blood gas values during their time in the ICU. However, no significant distinctions were detected between the groups in terms of oxygenation indices (partial pressures of oxygen/raction of inspired oxygen ratio) and partial pressures of carbon dioxide improvements. There was no considerable disparity observed between the VCV and PCV groups in the hospital mortality (32% vs 28%, P = 0.53), the number of days of ICU stay [median interquartile range (IQR): 9 (6-14) d vs 8 (5-13) d, P = 0.41], or the duration of the mechanical ventilation [median (IQR): 6 (4-10) d vs 5 (3-9) d, P = 0.47]. The PCV group displayed lower PAPs compared to the VCV group (P < 0.05) from the beginning of mechanical ventilation until extubation or ICU departure. The occurrence of barotrauma was considerably lower in the PCV group in comparison to the VCV group (6% vs 16%, P = 0.03). Both VCV and PCV were found to be effective in treating patients with acute COPD exacerbation. However, PCV was associated with lower PAPs and a significant decrease in barotrauma, thus indicating that it might be a safer ventilation method for this group of patients. However, further large-scale study is necessary to confirm these findings and to identify the best ventilation approach for patients experiencing an acute COPD exacerbation.

Volume-targeted ventilation vs pressure-controlled ventilation for very low birthweight infants: a protocol of a randomized controlled trial

BackgroundMechanical ventilation (MV) is essential in the management of critically ill neonates, especially preterm infants. However, inappropriate or prolonged use of invasive MV may result in ventilator-associated lung injury. A systemic review comparing pressure control ventilation (PCV) with volume-targeted ventilation mode (VTV) approved that VTV reduces the incidence of death or bronchopulmonary dysplasia (BPD) in neonates; however, this study did not analyze subgroups of very low birthweight (VLBW) infants. Therefore, the aim of this study was to compare the use of VTV and PCV in VLBW infants and to provide clinical evidence for reducing mortality and complications of MV in VLBW infants.MethodA single-center randomized controlled trial will be performed. All eligible infants will be randomized and assigned to either VTV or PCV group with 1:1 ratio using sealed envelopes. Death or BPD at 36 weeks’ postmenstrual age will be used as the primary outcome. Secondary outcomes include BPD, death, length of invasive MV, noninvasive mechanical ventilation, and oxygen use, length of hospital stay, failure of conventional MV, rate of using high-frequency oscillatory ventilation (HFOV) as rescue therapy, rate of reintubation within 48 h, and hospital expenses.DiscussionSystemic review suggested that VTV decreases the incidence of death or BPD in neonates compared to PLV; however, this study did not specifically analyze subgroups of VLBW infants. We designed this single-center randomized controlled trials (RCT) to add a significant contribution regarding the benefits of VTV for VLBW patients.

Pressure versus volume-controlled ventilation with BASKA mask airway in laparoscopic cholecystectomy: A randomized clinical study

ABSTRACT Background The best ventilation mode that suits with LMAs is still unclear. In this study, we investigated the ventilatory performance of Baska masks in patients who underwent elective laparoscopic cholecystectomy under general anaesthesia and pneumoperitoneum with either volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) mode. Methods Fifty-Six patients with ASA I – II, who underwent laparoscopic cholecystectomy, were randomly classified into VCV (n = 28) and PCV (n = 28) groups. The lung was ventilated with a tidal volume of 8 ml/kg in the VCV group. It was ventilated initially using an inflating pressure that delivered a tidal volume of 8 ml/kg with a maximum of 35 cmH2O in the PCV group. The primary outcome was the intraoperative oropharyngeal leak pressure (OLP) of the Baska mask. Secondary outcomes were intraoperative lung mechanics, arterial carbon dioxide levels, and perioperative adverse effects. Results After pneumoperitoneum inflation, the OLP, peak inflation pressure (PIP), mean pressure (Pmean), PaCO2, and end-tidal CO2 significantly increased, and the calculated dynamic compliance significantly decreased in both ventilation modes. All variables partially returned to baseline after pneumoperitoneum deflation. Patients ventilated with PCV mode demonstrated significantly lower PIP and PaCO2 levels but higher dynamic compliance with statistically comparable OLP-PIP difference and higher leak fraction. Conclusion In this study, Patients ventilated with PCV mode showed lower PIP and PaCO2 but higher dynamic compliance, and higher leak fraction. However, both modes investigated provided effective Baska mask ventilation and maintained the OLP throughout the procedure with a statistically comparable OLP-PIP difference.

Comparison of volume-controlled and pressure-controlled ventilation during laryngeal mask airway anesthesia in cataract surgery

Introduction: Most patients undergoing eye surgery are elderly adults with underlying cardiovascular diseases. One of the complications during recovery is gastric insufflation, which can cause detrimental effects on cardiovascular patients. The present study compares two methods of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). Methods: The study enrolled 81 patients undergoing cataract surgery (41 in the PCV group and 40 in the VCV group). According to the American Society of Anaesthesiologists (ASA) classes I and II received general anaesthesia and laryngeal mask airway (LMA) ventilation using VCV or PCV. Maximum pressure (Ppeak), dynamic compliance, expiratory tidal volume, Spo2, non-invasive blood pressure, heart rate, and pain in the epigastrium and umbilical region were monitored at intervals of 1, 5, 10, and 20 minutes after the initiation of anaesthesia and the results of two groups were compared. Results: The means of Ppeak and tidal volume in the PCV group as well as the means of dynamic compliance and end-tidal carbon dioxide (EtCO2) in the VCV group were significantly high. The mean diastolic blood pressure was significantly different between two groups at 20th minute. There were no significant differences in heart rate, mean systolic blood pressure, arterial oxygen saturation, or abdominal pain between two study groups. Conclusion: VCV had a lower Ppeak and a higher dynamic compliance, but PCV had a larger tidal volume and lower EtCO2. There were no differences in terms of abdominal and umbilicus pain, as well as hemodynamic parameters, between two groups.

Surgical bleeding in patients undergoing posterior lumbar inter-body fusion surgery: a randomized clinical trial evaluating the effect of two mechanical ventilation mode types

BackgroundThe purpose of the study was to compare the effect of using volume-controlled ventilation (VCV) versus pressure-controlled ventilation (PCV) on blood loss in patients undergoing posterior lumbar inter-body fusion (PLIF) surgery.MethodsIn a randomized, single-blinded, parallel design, 78 patients, candidates for PLIF surgery, were randomly allocated into two groups of 39 to be mechanically ventilated using VCV or PCV mode. All the patients were operated in prone position by one surgeon. Amount of intraoperative surgical bleeding, transfusion requirement, surgeon satisfaction, hemodynamic parameters, heart rate, and blood pressure were measured as outcomes.ResultsPCV group showed slightly better outcomes than VCV group in terms of mean blood loss (431 cc vs. 465 cc), transfusion requirement (0.40 vs. 0.43 unit), and surgeon satisfaction (82.1% vs. 74.4%); however, the differences were not statistically significant. Diastolic blood pressure 90 and 105 min after induction were significantly lower in PCV group (P = 0.043–0.019, respectively); however, blood pressure at other times, hemoglobin levels, and mean heart rate were similar in two groups.ConclusionsIn patients undergoing posterior lumbar inter-body fusion surgery, mode of ventilation cannot make significant difference in terms of blood loss; however, some minor benefits in outcomes may lead to the selection of PCV rather than VCV. More studies with larger sample size, and investigating more factors may be needed.

Effect of volume-controlled and pressure-controlled ventilation modes on cerebral oximetry in laparoscopic cholecystectomy: a randomized controlled trial

This study aimed to compare the effect of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes on cerebral oximetry during laparoscopic cholecystectomy using near-infrared spectroscopy (NIRS). Seventy patients who underwent elective laparoscopic cholecystectomy were randomized to receive either VCV (group V) or PCV (group P). Demographic and operative data (anesthesia, surgery and insufflation durations) were recorded. The primary outcome was the NIRS value, while the secondary outcomes were peripheral oxygen saturation (SpO2), blood gas parameters and peak and plateau pressures in mechanical ventilation. Measurements were conducted at the start of anesthesia (T0), end of intubation (T1), 5 min after insufflation (T2), just before desufflation (T3), and 5 min after desufflation (T4). Both groups were comparable in terms of age, sex, body mass index, intraoperative time, anesthesia and insufflation durations. The average NIRS right T1–T2–T3 and left T2–T3 values were significantly higher in group P than in group V (p = 0.030, p = 0.001, p = 0.001, p = 0.006 and p = 0.002 respectively). In contrast, the mean peak and mean plateau pressures in group P at T1, T2 and T4 were significantly lower than those in group V (p = 0.003, p = 0.001, p &lt; 0.001, p = 0.011, p = 0.001 and p &lt; 0.001 respectively).The PCV mode allows better cerebral oxygenation than VCV while maintaining lower peak pressure and plateau pressures.

Individualised flow-controlled ventilation versus pressure-controlled ventilation in a porcine model of thoracic surgery requiring one-lung ventilation: A laboratory study.

Flow-controlled ventilation (FCV) enables precise determination of dynamic compliance due to a continuous flow coupled with direct tracheal pressure measurement. Thus, pressure settings can be adjusted accordingly in an individualised approach. The aim of this study was to compare gas exchange of individualised FCV to pressure-controlled ventilation (PCV) in a porcine model of simulated thoracic surgery requiring one-lung ventilation (OLV). Controlled interventional trial conducted on 16 domestic pigs. Animal operating facility at the Medical University of Innsbruck. Thoracic surgery was simulated with left-sided thoracotomy and subsequent collapse of the lung over a period of three hours. When using FCV, ventilation was performed with compliance-guided pressure settings. When using PCV, end-expiratory pressure was adapted to achieve best compliance with peak pressure adjusted to achieve a tidal volume of 6 ml kg -1 during OLV. Gas exchange was assessed by the Horowitz index (= P aO 2 /FIO 2 ) and CO 2 removal by the P aCO 2 value in relation to required respiratory minute volume. In the FCV group ( n = 8) normocapnia could be maintained throughout the OLV trial despite a significantly lower respiratory minute volume compared to the PCV group ( n = 8) (8.0 vs. 11.6, 95% confidence interval, CI -4.5 to -2.7 l min -1 ; P < 0.001), whereas permissive hypercapnia had to be accepted in PCV ( P aCO 2 5.68 vs. 6.89, 95% CI -1.7 to -0.7 kPa; P < 0.001). The Horowitz index was comparable in both groups but calculated mechanical power was significantly lower in FCV (7.5 vs. 22.0, 95% CI -17.2 to -11.8 J min -1 ; P < 0.001). In this porcine study FCV maintained normocapnia during OLV, whereas permissive hypercapnia had to be accepted in PCV despite a substantially higher minute volume. Reducing exposure of the lungs to mechanical power applied by the ventilator in FCV offers a possible advantage for this mode of ventilation in terms of lung protection.

COMPLIANCE-GUIDED FLOW CONTROLLED VENTILATION VS PRESSURE-CONTROLLED VENTILATION IN AN EXPERIMENTAL MODEL OF OLEIC ACID-INDUCED ARDS

TYPE: Abstract TOPIC: Critical Care PURPOSE: Aim of this study was to investigate efficiency of gas exchange and impact on circulation of individualized flow controlled ventilation (FCV) compared to pressure controlled ventilation (PCV) in a porcine model of oleic acid induced acute respiratory distress syndrome (ARDS). METHODS: In lung healthy pigs ARDS was induced by intravenous application of oleic acid until moderate to severe ARDS at a stable Horowitz index of 80-120 (paO2 / FiO2) was reached over a period of 30 minutes. Ventilation was either performed with individualized FCV established by compliance-guided pressure settings or PCV with compliance-guided titration of positive end-expiratory pressure and peak pressure set to achieve a tidal volume of 6 ml/kg over a period of 2 hours. RESULTS: The FCV group (n=8) showed significantly improved oxygenation (149.2 vs. 110.4 Horowitz index, p=0.027) and CO2 removal (paCO2 54.4 vs. 67.9 mmHg, p=0.006) at a significantly lower respiratory minute volume (8.4 vs. 11.9 l/min, p=0.005) compared to the PCV group (n=8). Additionally, in FCV hemodynamic stabilisation without an increase of cardiac index (4.5 vs. 8.6 l/min/m2, p<0.001) and a significant reduction of catecholamine support (norepinephrine 0.26 vs. 0.86 μg/kg/min, p=0.037) during 2 hours of ventilation was found. CONCLUSIONS: In this oleic acid induced porcine ARDS model individualized FCV significantly improved gas exchange and hemodynamic stability compared to best clinical practice PCV. CLINICAL IMPLICATIONS: FCV may represent a promising ventilation mode to improve outcome in ARDS patients but further clinical studies are warranted to safely implement FCV in routine patient care. DISCLOSURE: Support was provided from institutional and department sources, as well as research funding provided by Ventinova Medical B.V. to cover animal costs. KEYWORD: ARDS

Effects of pressure- and volume-controlled ventilation on the work of breathing in cats using a cuffed endotracheal tube.

Background and Aim:Mechanical ventilation is essential for supporting patients’ respiratory function when they are under general anesthesia. For cats with limited lung capacity, the different effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) on respiratory function remain elusive. The objective of the present study was to compare the efficacy of VCV and PCV in cats under general anesthesia using a cuffed endotracheal tube (ETT).Materials and Methods:Twelve healthy cats were randomly allocated to either a VCV or PCV group. Five tidal volumes (6, 8, 10, 12, and 14 mL/kg) were randomly applied to assess the efficacy of VCV, and respiratory rates were adjusted to achieve a minute ventilation of 100 mL/kg/min. Peak inspiratory pressures (4, 5, 6, 7, and 8 mmHg) were randomly applied to assess the efficacy of PCV, and respiratory rates were adjusted to achieve a minute ventilation of 100 mL/kg/min. Blood pressure, gas leakages, and end-tidal CO2 were recorded from 60 trials for airway control during the use of VCV or PCV. Data were compared using Fisher’s exact test with a significance level of p<0.05.Results:Leakages did not differ between VCV (1/60 events) and PCV (0/60 events; p=0.500). Hypercapnia was identified when using VCV (6/60 events) less frequently than when using PCV (7/60 events; p=0.762), but did not reach statistical significance. Hypotension (mean arterial blood pressure <60 mmHg) occurred less frequently with VCV (0/60 events) than with PCV (9/60 events; p=0.003). Moreover, VCV provided a significantly lower work of breathing (151.10±65.40 cmH2O mL) compared with PCV (187.84±89.72 cmH2O mL; p<0.05).Conclusion:VCV in cats using a cuffed ETT causes less hypotension than PCV. It should be noted that VCV provides a more stable tidal volume compared with PCV, resulting in a more stable minute volume. Nonetheless, VCV should not be used in patients with an airway obstruction because higher peak airway pressure may occur and lead to lung injury.

Efficacy and safety of an open lung ventilation strategy with staircase recruitment followed by comparison on two different modes of ventilation, in moderate ARDS in cirrhosis: A pilot randomized trial.

BackgroundMechanical ventilation in cirrhosis with acute respiratory distress syndrome (ARDS) is not widely studied. We aimed to study the effect of the staircase recruitment manoeuvre followed by two different modes of ventilation.MethodsThirty patients with cirrhosis with moderate ARDS underwent the staircase recruitment manoeuvre followed by randomisation to volume control or pressure control group.ResultsThe PaO2/FiO2 ratio showed a significant improvement in both the groups after recruitment. The improvement was significantly higher in the pressure control ventilation (PCV) group at the end of the first hour as compared to the volume control ventilation (VCV) group. However, this difference was not significant at the end of 6 and 12 h. In the PCV group it improved from 118.47 ± 10.21 at baseline to 189.87 ± 55.18 12 h post-recruitment. In the VCV group it improved from 113.79 ± 13.22 at baseline to 180.93 ± 81.971. Static lung compliance also improved in both the groups significantly (P < 0.001). The PCV group showed an improvement from 25.42 ± 11.94 mL/cm H2O at baseline to 29.51 ± 14.58 mL/cm H2O. In the VCV group the lung compliance improved from 24.78 ± 4.87 mL/cm H2O to 31.31 ± 10.88 mL/cm H2O.ConclusionThis study shows that stepwise recruitment manoeuvre is an effective rescue therapy to improve oxygenation in cirrhosis with moderate ARDS. PCV may have an advantage over VCV in terms of better oxygenation.

Airway Pressure Release Ventilation Mode Improves Circulatory and Respiratory Function in Patients After Cardiopulmonary Bypass, a Randomized Trial.

ImportancePostoperative pulmonary complications and cardiovascular complications are major causes of morbidity, mortality, and resource utilization in cardiac surgery patients.ObjectivesTo investigate the effects of airway pressure release ventilation (APRV) on respiration and hemodynamics in post cardiac surgery patients.Main Outcomes and MeasuresA single-center randomized control trial was performed. In total, 138 patients undergoing cardiopulmonary bypass were prospectively screened. Ultimately 39 patients met the inclusion criteria and were randomized into two groups: 19 patients were managed with pressure control ventilation (PCV) and 20 patients were managed with APRV. Respiratory mechanics after 4 h, hemodynamics within the first day, and Chest radiograph score (CRS) and blood gasses within the first three days were recorded and compared.ResultsA higher cardiac index (3.1 ± 0.7 vs. 2.8 ± 0.8 L⋅min–1⋅m2; p < 0.05), and shock volume index (35.4 ± 9.2 vs. 33.1 ± 9.7 ml m–2; p < 0.05) were also observed in the APRV group after 4 h as well as within the first day (p < 0.05). Compared to the PCV group, the PaO2/FiO2 was significantly higher after 4 h in patients of APRV group (340 ± 97 vs. 301 ± 82, p < 0.05) and within the first three days (p < 0.05) in the APRV group. CRS revealed less overall lung injury in the APRV group (p < 0.001). The duration of mechanical ventilation and ICU length of stay were not significantly (p = 0.248 and 0.424, respectively).Conclusions and RelevanceCompared to PCV, APRV may be associated with increased cardiac output improved oxygenation, and decreased lung injury in postoperative cardiac surgery patients.

Effects of ventilation mode type on intra-abdominal pressure and intra-operative blood loss in patients undergoing lumbar spine surgery: A randomised clinical study.

Background and Aims:The aim of the study was to evaluate the effect of mode of mechanical ventilation; pressure-controlled ventilation (PCV) vs. volume-controlled ventilation (VCV) on airway pressures, intra-abdominal pressure (IAP) and intra-operative surgical bleeding in patients undergoing lumbar spine surgery.Methods:This was a prospective, randomised study that included 50 American Society of Anesthesiologists class I and II patients undergoing lumbar spine surgery who were mechanically ventilated using PCV or VCV mode. The respiratory parameters (peak and plateau pressures) and IAP were measured after anaesthesia induction in supine position, 10 min after the patients were changed from supine to prone position, at the end of the surgery in prone position, and after the patients were changed from prone to supine position. The amount of intraoperative surgical bleeding was measured by objective and subjective methods.Results:The primary outcome was the amount of intraoperative surgical bleeding. It was significantly less in the PCV group than in the VCV group (137 ± 24.37 mL vs. 311 ± 66.98 mL) (P = 0.000). Similarly, on comparing other parameters like peak inspiratory pressures, plateaupressures and IAP, the patients in PCV group had significantly lower parameters than those in VCV group (P < 0.05). No harmful events were recorded.Conclusion:In patie,nts undergoing lumbar spine surgery, use of PCV mode decreased intraoperative surgical bleeding, which may be related to lower intraoperative respiratory pressures and IAP.

Pressure Controlled Ventilation versus Volume-Controlled Ventilation Regarding Hemodynamics and Stress Response for Posterior Lumbar Spine Surgeries in The Prone Position

Background: Prone positioning may induce alterations of airway pressures and hemodynamic that may affect intraoperative blood loss. Ventilation mode may modify these alterations. Objective: Our study aimed to differences between pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) in their effects on hemodynamic changes during posterior lumbar surgeries performed in the prone position. Patients and Methods: This is a prospective randomized controlled study, which was performed in the Department of Anaesthesiology and Surgical ICU, Aswan university, Egypt at the duration from 1-6-2017 to 13-12-2018 for 60 patients who had posterior lumbar spine surgery in prone position who were eligible to inclusion/exclusion criteria divided into two groups; Group (I) were received VCV mode (n = 30) and Group (II) were received PCV mode (n = 30) then study parameters were recorded intraoperatively and postoperatively in the two groups of ventilation modes. Results: As regarding heart rate, mean arterial blood pressure, serum glucose level, and serum cortisol level, they were statistically significantly lower in PCV group than VCV group both intraoperative and postoperative which reflects that stress response is lower with PCV more than VCV and that may have also a rule in decreasing intraoperative blood loss and improving the surgical field in these surgeries. Conclusions: for lumbar spine surgeries in the prone position, PCV was associated with decreased HR, blood pressure, cortisol, glucose levels compared with VCV. The stress response is lesser with PCV which is better for this type of patients.

Pressure Controlled Ventilation versus Volume-Controlled Ventilation Regarding Hemodynamics and Stress Response for Posterior Lumbar Spine Surgeries in The Prone Position

Background: Prone positioning may induce alterations of airway pressures and hemodynamic that may affect intraoperative blood loss. Ventilation mode may modify these alterations. Objective: Our study aimed to differences between pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) in their effects on hemodynamic changes during posterior lumbar surgeries performed in the prone position. Patients and Methods: This is a prospective randomized controlled study, which was performed in the Department of Anaesthesiology and Surgical ICU, Aswan university, Egypt at the duration from 1-6-2017 to 13-12-2018 for 60 patients who had posterior lumbar spine surgery in prone position who were eligible to inclusion/exclusion criteria divided into two groups; Group (I) were received VCV mode (n = 30) and Group (II) were received PCV mode (n = 30) then study parameters were recorded intraoperatively and postoperatively in the two groups of ventilation modes. Results: As regarding heart rate, mean arterial blood pressure, serum glucose level, and serum cortisol level, they were statistically significantly lower in PCV group than VCV group both intraoperative and postoperative which reflects that stress response is lower with PCV more than VCV and that may have also a rule in decreasing intraoperative blood loss and improving the surgical field in these surgeries. Conclusions: for lumbar spine surgeries in the prone position, PCV was associated with decreased HR, blood pressure, cortisol, glucose levels compared with VCV. The stress response is lesser with PCV which is better for this type of patients.

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.