Biphasic Positive Airway Pressure Ventilation Research Articles

Biphasic positive airway pressure spontaneous breathing attenuates lung injury in an animal model of severe acute respiratory distress syndrome

ObjectiveTo compare the effects of unassisted spontaneous breathing (SB) and complete muscle paralysis (PC) on early severe acute respiratory distress syndrome (ARDS) in an animal model, and to explore the possibility of biphasic positive airway pressure (BIPAP) as lung protective ventilation support for patients in the early stage of severe ARDS.MethodsTwelve healthy beagle dogs between the ages of 10 and 15 months were randomly divided into two groups: the SB group (BIPAPSB) and the PC group (BIPAPPC). Arterial blood samples were drawn before modelling. Arterial blood gas analysis and mechanical tests were conducted. The animal model of severe ARDS was established using a deep intravenous injection of oleic acid, and BIPAP ventilation was performed for 8 hours. Lung tissue and blood were taken to detect lung function, inflammatory reactions and degree of pathological damage.ResultsAt the beginning of the experiment, there was no significant difference in the arterial blood gas analysis between the two groups (p > 0.05). After successful modelling, the oxygenation index and the end-expiratory lung volume in the SB group were significantly higher than those in the PC group 8 hours after MV. Pathologically, the wet-dry ratio and pathological score of the PC group were higher than those of the SB group; the lung injury in the gravity-dependent area in the SB group was less than that in the PC group (p< 0.05).ConclusionsIn the early stage of severe ARDS induced by oleic acid, compared with PC, retention of the BIPAP mode of SB can reduce the risk of lung injury and improve respiratory function.

Impact of different frequencies of controlled breath and pressure-support levels during biphasic positive airway pressure ventilation on the lung and diaphragm in experimental mild acute respiratory distress syndrome.

We hypothesized that a decrease in frequency of controlled breaths during biphasic positive airway pressure (BIVENT), associated with an increase in spontaneous breaths, whether pressure support (PSV)-assisted or not, would mitigate lung and diaphragm damage in mild experimental acute respiratory distress syndrome (ARDS). Wistar rats received Escherichia coli lipopolysaccharide intratracheally. After 24 hours, animals were randomly assigned to: 1) BIVENT-100+PSV0%: airway pressure (Phigh) adjusted to VT = 6 mL/kg and frequency of controlled breaths (f) = 100 bpm; 2) BIVENT-50+PSV0%: Phigh adjusted to VT = 6 mL/kg and f = 50 bpm; 3) BIVENT-50+PSV50% (PSV set to half the Phigh reference value, i.e., PSV50%); or 4) BIVENT-50+PSV100% (PSV equal to Phigh reference value, i.e., PSV100%). Positive end-expiratory pressure (Plow) was equal to 5 cmH2O. Nonventilated animals were used for lung and diaphragm histology and molecular biology analysis. BIVENT-50+PSV0%, compared to BIVENT-100+PSV0%, reduced the diffuse alveolar damage (DAD) score, the expression of amphiregulin (marker of alveolar stretch) and muscle atrophy F-box (marker of diaphragm atrophy). In BIVENT-50 groups, the increase in PSV (BIVENT-50+PSV50% versus BIVENT-50+PSV100%) yielded better lung mechanics and less alveolar collapse, interstitial edema, cumulative DAD score, as well as gene expressions associated with lung inflammation, epithelial and endothelial cell damage in lung tissue, and muscle ring finger protein 1 (marker of muscle proteolysis) in diaphragm. Transpulmonary peak pressure (Ppeak,L) and pressure-time product per minute (PTPmin) at Phigh were associated with lung damage, while increased spontaneous breathing at Plow did not promote lung injury. In the ARDS model used herein, during BIVENT, the level of PSV and the phase of the respiratory cycle in which the inspiratory effort occurs affected lung and diaphragm damage. Partitioning of inspiratory effort and transpulmonary pressure in spontaneous breaths at Plow and Phigh is required to minimize VILI.

Influence of biphasic positive airway pressure ventilation on lung function and serum cytokines in patients with bronchial asthma

Objective To explore the influence of biphasic positive airway pressure (BiPAP) ventilation on lung function and serum cytokines in the treatment of patients with bronchial asthma. Methods 107 patients with moderate to severe bronchial asthma were divided into two groups according to the random number table method.The control group (n=54) received general supportive treatment such as expectorant, suck oxygen, balancing the water and electrolyte, anti-infection treatment.The observation group (n=53) was given BiPAP non-invasive ventilation based on the treatment of the control group.After treatment for 7 days, the clinical efficacy, improvement of lung function and serum cytokines between the two groups were compared. Results The effective rate of the observation group was 88.68%, which was higher than 72.22% of the control group, the difference was statistically significant (χ2=4.592, P=0.032). The total effective rate of the observation group was 96.23%, which was higher than 83.64% of the control group, the difference was statistically significant (χ2=4.677, P=0.031). The FEV1, FEV1/FVC, PEF levels of the observation group after treatment were (1.95±0.27)L, (65.33±6.21)%, (5.55±0.34)L/s, respectively, which were higher than those of the control group[(1.66±0.24)L, (58.24±6.09)%, (4.70±0.39)L/s], the differences were statistically significant (t=-5.872, -5.961, -12.016, all P<0.05). The serum levels of IL-4, IL-5, IL-13, IL-17, IFN-γ of the observation group after treatment were (136.77±84.63)pg/mL, (145.06±67.33)pg/mL, (12.67±4.02)ng/mL, (7.15±0.87)ng/L, (507.51±169.33)ng/L, respectively, which were lower than those of the control group[(186.95±81.36)pg/mL, (193.35±63.20)pg/mL, (14.59±3.97)ng/mL, (7.76±0.99)ng/L, (655.76±183.95)ng/L], the differences were statistically significant (t=3.136, P=0.000; t=3.832, P=0.000; t=2.497, P=0.015; t=3.389, P=0.000; t=4.341, P=0.000). Conclusion BiPAP non-invasive ventilation in the treatment of patients with moderate to severe bronchial asthma can effectively improve the lung function and reduce inflammatory cytokines, which has important reference value in clinic. Key words: Biphasic positive airway pressure; Bronchial asthma; Lung function; Cytokines

Effects of different levels of spontaneous breathing activity during biphasic positive airway pressure ventilation on lung function and pro-inflammatory response in an experimental model of acute lung injury

Carvalho, N. C.,; Güldner, A.; Beda, A.; Spieth, P; Rentzsch, I.; de Abreu, Gama M. Author Information

Regional lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in experimental lung injury

IntroductionThere is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute lung injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional lung aeration and ventilation during ALI are only poorly defined.MethodsIn 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at lung apex, hilum and base.ResultsCompared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern.ConclusionsIn this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean.

Effectiveness of Alveolar Opening in Patients with Acute Lung Injury and Concomitant Pneumothorax

Objective: to study the efficiency of a lung opening maneuver in patients with acute lung injury (ALI) and concomitant pneumothorax, who were on biphasic positive airway pressure ventilation (BIPAP) and synchronized intermittent mandatory ventilation. Subject and methods. Seventy-three patients with acute lung injury and concomitant pneumoth-orax resulting from blunt chest trauma were examined. Their condition was an APACHE II of 18—24 scores. After elimination of pneumothorax, an open lung maneuver was made using different modes of lung support 3—5 times daily. Results. The study has shown that BIPAP used in patients with ALI and concomitant pneumothorax reduces the time of pleural cavity drainage, which allows the lung opening maneuver to be applied earlier. The employment of the latter in patients with ALI and pneumothorax permits a prompter recovery of lung function during different types of respiratory support, which is attended by reductions in the number of complications, artificial ventilation, and mortality. When the lung opening maneuver is combined with BIPAP, its efficiency considerably increases. Key words: acute lung injury, pneumothorax, BIPAP, lung opening maneuver.

Changes in Functional Residual Capacity During Weaning from Mechanical Ventilation: A Pilot Study

Reduction of high positive end-expiratory pressure levels and pressure support ventilation (PSV) are frequently used before tracheal extubation in critically ill patients, but the impact of PSV on functional residual capacity (FRC) is unknown. In this study, we sought to detect the changes of FRC and pulmonary function during a weaning protocol in patients ventilated after cardiac surgery. The LUFU system (Dräger Medical, Lübeck, Germany) estimates FRC by oxygen washout, a variant of multiple breath nitrogen washout, using a sidestream O(2) analyzer. Postoperative cardiac surgery patients were initially ventilated using biphasic positive airway pressure ventilation (BiPAP) with a positive end-expiratory pressure of 10 mbar. The upper pressure limit was adjusted to deliver a tidal volume of 6-8 mL/kg (BIPAP 10). After 30 min, the upper and lower pressure limits were both reduced by 3 mbar (BIPAP 7). When spontaneous breathing efforts were detected, ventilation mode was switched to continuous positive airway pressure (CPAP) with PSV using the former lower pressure limit as the CPAP level and the corresponding pressure support of the former BIPAP adjustment (CPAP 7_1). Measurements were repeated after 30 min (CPAP 7_2). Ten patients were studied. FRC decreased (BIPAP 10: 3.6 [1.0] L; BIPAP 7: 3.1 [0.9] L; CPAP 7_1: 2.9 [0.9] L; CPAP 7_2: 2.7 [0.6] L [Mean (SD)]; MANOVA: P = 0.017), as did PF ratio (BIPAP 10: 420 [114] mm Hg; BIPAP 7: 405 [110] mm Hg; CPAP 7_1: 353 [70] mm Hg; CPAP 7_2: 340 [70] mm Hg [Mean (SD)]; MANOVA: P = 0.045). PaCO(2) did not change significantly over time (P = 0.221). Decreasing FRC during the weaning process after cardiac surgery may, at least in part, be explained by alveolar derecruitment. Whether this variable could help guide a weaning protocol has to be studied further.

Application of biphasic positive airway pressure mechanical ventilation in neonatal respiratory failure

Objective To evaluate the effect of biphasic positive airway pressure(BIPAP) mechanical ventilation on neonatal respiratory failure and compare it with conventional mechanical ventilation(CMV).Methods Fifty neonates with respiratory failures were randomly divided into BIPAP group (n=28) and CMV group (n=22).The dosage of Luminal was recorded and blood gas as well as mean airway pressure(MAP) were monitored at 0 h,6～12h、24～48h、48h after ventilation.Results 48 patients were discharged from the hospital,2 died of multiple organ failure.In BIPAP group,the total duration of mechanical ventilation was (70±35)h,which was significantly less than that (99±44)h in CMV group (P<0.05).The dosage of Luminal used during mechanical ventilation was significantly greater in CMV group than that in BIPAP group (P<0.05).MAP was significantly higher in CMV group than that in BIPAP group 24?h after ventilation (P<0.05).No significant difference in PaO2、PaCO2 and pH was found between the two modes.Conclusion BIPAP is an effective mode of mechanical ventilation therapy for neonatal respiratory failure and is operated easily and safely. Key words: Biphasic positive airway pressure ventilation; Conventional mechanical ventilation; Respi-ratory failure; Infant,newborn

Airway Pressure Release and Biphasic Intermittent Positive Airway Pressure Ventilation: Are They Ready for Prime Time?

Airway pressure release ventilation and biphasic positive airway pressure ventilation are being used increasingly as alternative strategies to conventional assist control ventilation for patients with acute respiratory distress syndrome (ARDS) and acute lung injury. By permitting spontaneous breathing throughout the ventilatory cycle, these modes offer several advantages over conventional strategies to improve the pathophysiology in these patients, including gas exchange, cardiovascular function, and reducing or eliminating the need for heavy sedation and paralysis. Whether these surrogate outcomes will translate into better patient outcomes remains to be determined. The purpose of this review is to summarize the rationale behind the use of these ventilatory strategies in ARDS, the clinical experience with the use of these modes, and their future applications in trauma patients.

Comparison of ventilatory and haemodynamic effects of BIPAP and S-IMV/PSV for postoperative short-term ventilation in patients after coronary artery bypass grafting

The aim of the present multiple cross-over study was to compare the effects of biphasic positive airway pressure (BIPAP) ventilation with synchronized intermittent mandatory ventilation combined with pressure support ventilation (S-IMV/PSV) in sedated and awake patients after coronary artery bypass grafting (CABG) surgery. Twenty-four patients with no evidence of preoperative respiratory dysfunction and an uncomplicated intraoperative course were investigated. The patients were randomly assigned to one of two groups starting with either BIPAP or S-IMV/PSV mode. Haemodynamic measurements and blood gas analyses were performed during sedation with 2.0 mg kg−1 h−1 propofol in the primary mode, after switching to the alternative ventilatory mode, and in the primary mode again. The same sequence of measurements was repeated in awake patients who had reached extubation criteria. In awake patients, PSV was performed instead of S-IMV. Statistical analysis of data was performed using non-parametric tests. Inspiratory peak pressure increased significantly during S-IMV/PSV in sedated patients in both groups. Other ventilatory parameters did not differ significantly between BIPAP and S-IMV/PSV in both groups. Similarly, haemodynamic parameters and blood-gas analyses did not vary with the ventilatory mode. Our results demonstrate that BIPAP ventilation has comparable effects on haemodynamics and pulmonary gas exchange compared with S-IMV/PSV and PSV when used for short-term ventilatory support in patients after cardiac surgery.

Prinzipien für die Entwöhnung von der mechanischen Beatmung und deren Berücksichtigung in neuen Beatmungsmodi

Transfer of both ventilatory work and control of breathing from the ventilator to the patient are the hallmarks of weaning from mechanical ventilation. According to these principles, we investigated four modern ventilatory modes for supported spontaneous breathing: Pressure Support Ventilation (PSV; ASB, IPS), Biphasic Positive Airway Pressure Ventilation (BIPAP), and Proportional Assist Ventilation (PAV, PPS) with Automatic Tube Compensation (ATC).

Volume-controlled versus biphasic positive airway pressure ventilation in leukopenic patients with severe respiratory failure

To study comparatively the effects of volume-controlled vs. biphasic positive airway pressure mechanical ventilation on respiratory mechanics and oxygenation in leukopenic patients with severe respiratory failure. Prospective, comparative study. Medical intensive care unit of a university hospital. Leukopenic (<1000 leukocytes/microliter) patients (n=20) after cytoreductive chemotherapy requiring mechanical ventilation for severe respiratory failure (Murray score of > 2.5). Patients were assigned in a consecutive, alternating manner to receive either volume-controlled or biphasic positive airway pressure mechanical ventilation, starting within 12 to 24 hrs after endotracheal intubation. Tidal volume, inspiratory flow, peak inspiratory and positive end-expiratory pressures, FIO2, and arterial blood gas analyses were recorded hourly for a study period of 48 hrs. Biphasic positive airway pressure ventilation was associated with a significant reduction in peak inspiratory pressure (mean differences at 24, 36, and 48 hrs: 4.4, 3.4, and 4.2 cm H2O; p = .024, .019, and .013, respectively) and positive end-expiratory pressures (mean differences at 24, 36, and 48 hrs: 1.6, 1.4, and 1.5 cm H20; p = .023, .024, and .023, respectively) at significantly lower FIO2 (mean differences at 12, 24, 36, and 48 hrs; p = .007, .015, .016, and .011, respectively). PaO2/FIO2 ratios and CO2 removal were similar under ventilatory conditions. Biphasic positive airway pressure ventilation offers the advantage of significantly reduced peak inspiratory and positive end-expiratory pressures at a lower FIO2 and with at least similar oxygenation and CO2 removal as achieved by volume-controlled mechanical ventilation. Our results are in line with previous reports on nonleukopenic patients and suggest that the positive effects of pressure-limited mechanical ventilation are independent of circulating white blood cells. Further studies are mandatory to demonstrate clinical benefit in this critically ill patient population.