Airway Pressure Release Ventilation Research Articles (Page 1)

RationaleRestrictive lung disease is common in pediatric patients, leading to acute-on-chronic respiratory failure and the need for invasive mechanical ventilation. There is no consensus on lung recruitment maneuvers.ObjectivesTo examine the use of airway pressure release ventilation (APRV) in patients with restrictive lung disease as an effective open-lung tool maneuver.MethodsThis single-center retrospective case series included patients with restrictive lung disease in a 28-bed pediatric intensive care unit from 2013 to 2024, who developed acute-on-chronic respiratory failure requiring invasive mechanical ventilation. Inclusion criteria were ventilation for at least 48 h, with at least 24 h in APRV. Descriptive statistics were performed.Measurements and main results18 patient encounters met inclusion criteria. Subjects were divided into two groups: neuromuscular disease (14 encounters) and truncal obesity (4 encounters). Lung surface area improved significantly in the first 12–24 h of APRV use: neuromuscular group by 7,600 mm2 [95% CI, 4,000–11,000 mm2]; p < 0.001, and obesity group by 15,000 mm2 [95% CI, 3,000–27,000]; p = 0.018. Atelectasis improved at 12–24 h and 48 h from starting APRV, with mean differences of 14% [95% CI, 4%–24%]; p = 0.005 and 14% [95% CI, 3%–25%]; p = 0.009, respectively. As expected, oxygenation improved substantially in both groups.ConclusionAPRV is a safe and effective method for improving atelectasis and oxygenation in children with RLD related to neuromuscular conditions and obesity. Further high-quality prospective studies are needed to establish clear guidelines for its use.

Airway pressure release ventilation on veno-venous extracorporeal membrane oxigenation (ECMO).

To use digital twins constructed based on data from patients with acute respiratory distress syndrome (ARDS) to calculate all key indices of ventilator-induced lung injury (VILI) during airway pressure release ventilation (APRV), and to compare them with corresponding values obtained during pressure-controlled ventilation (PCV). Digital twins were created by matching a high-fidelity cardiopulmonary simulation model to each patient's data. Interdisciplinary Collaboration in Systems Medicine Research Network. A dataset consisting of pairs of ventilator settings and arterial blood gases for 98 patients with ARDS receiving PCV. VILI indices were calculated for each recorded PCV datapoint, and for typical APRV settings in fixed and time-controlled adaptive modes, in the same digital twins. Global optimization algorithms evaluated greater than 4.8 million changes to these settings to identify the lowest values of VILI indices that could be achieved in both modes while preserving adequate gas-exchange. In digital twins, APRV settings of inspiratory pressure equals to 25 cm H2O, low-pressure setting equals to 0 cm H2O, inspiration time equals to 5 s, and expiration time set to achieve 75% of peak expiratory flow rate (mean 0.5 s), reduced mean mechanical power (MP) by 32% and mean tidal alveolar recruitment/de-recruitment by 34% compared with documented PCV settings, at the cost of moderate hypercapnia (mean PaCO2 58.5 mm Hg, pHa 7.32 vs. PaCO2 45.6 mm Hg, pHa 7.37). Mean driving pressure, tidal volume, and lung stress/strain were similar in both modes. Computational optimization showed that these settings were close to optimal in terms of minimizing both mean MP and mean levels of tidal recruitment/de-recruitment during APRV. Using digital twins we found possible lung-protective conditions and beneficial effects of APRV which need further evaluation in randomized clinical trials.

According to the progress in medical devices, respirators are improving to avoid ventilator-associated lung injury with new technology and concepts. At first, we need to know the methods of respirator settings; they are the respiratory mode and method. Respiratory modes are assist/control (A/C), synchronized intermittent mandatory ventilation (SIMV), and continuous positive airway pressure (CPAP). The respiratory methods are volume-controlled ventilation (VCV), pressure-controlled ventilation (PCV), and pressure support ventilation (PSV). The new methods of ventilation are airway pressure release ventilation (APRV) and neurally adjusted ventilatory assist (NAVA). To protect the lung injury by ventilation, we need to control the limitation of ventilation volume in one breath, high positive end-expiratory pressure, plateau pressure in lung alveoli, auto positive end-expiratory pressure, and driving pressure in respiration. Coming to the new devices, lung injury would be mitigated by mechanical ventilation.

Background: The airway pressure release ventilation (APRV)-based time controlled adaptive ventilation (TCAV) protocol can potentially minimize ventilator-induced lung injury (VILI). Inspiratory pressure rise time (IPRT) is a parameter available in pressure-controlled ventilation modes, yet its role within TCAV remains unclear. We hypothesized that varying IPRTs impact lung emptying and associated ventilatory parameters (driving pressure [ΔP], intrinsic PEEP [PEEPi], exhaled tidal volume [VTe]). Methods: This single-center, prospective exploratory study included 10 intubated subjects ventilated utilizing the TCAV protocol. Subjects underwent consecutive experimental trials with IPRTs of 500 and 1,000 ms, each preceded by a baseline (BL) with an IPRT of 0 ms. Analyzed parameters were ventilator-derived ΔP (ΔPvent), PEEPi, and VTe. Elastance (ERS = ΔPvent/VTe) and elastance-derived ΔP (ΔPelast = ERS × VTe) were calculated. End-expiratory lung volume (EELV) and end-inspiratory lung volume were assessed through electrical impedance tomography (EIT). Results: Prolonged IPRT increased ΔPelast compared with ΔPvent in each baseline/trial combination (ΔPvent 13.5 ± 1.5 cm H2O vs ΔPelast 18.4 ± 2.7 cm H2O at 1,000 ms IPRT, P < .001) through a loss of PEEPi. Conventional PEEPi measurements did not detect these changes. The EIT data showed a reduction in EELV during the trials. Conclusions: IPRT prolongation under TCAV reduced EELV/PEEPi, therefore increasing ΔP. Conventional PEEPi measurement methods are misleading in this context. We therefore suggest adding the recommendation to set IPRT to 0 ms for the TCAV protocol.

Combination of airway pressure release ventilation and furosemide-induced metabolic alkalosis in a pediatric patient with severe acute respiratory distress syndrome: A case report

Abstract Background: The scholarship of teaching and learning (SoTL) emphasizes the synergy between teaching and research, focusing on knowledge creation, sharing and the translation of research into learning. During the COVID-19 pandemic the critical care environment faced significant challenges as novel mechanical ventilation strategies were implemented. This article explores the conceptualisation of an interactive workshop as a research methodology within the pragmatic paradigm, emphasizing authenticity to address ethical tensions inherent in researcher-participant collaboration. Objectives: This study aimed to evaluate the workshop as a collaborative platform for creating actionable knowledge. The workshops yielded dense qualitative data while addressing authenticity criteria to balance ethical considerations and data integrity. Methods: Adopting a pragmatic stance, the researchers facilitated a three-step, semi-structured, interactive workshop involving 19 purposefully selected content specialists (critical care nursing specialists) in South Africa. The workshop emphasized collaboration, co-creation, and dialogic consensus-building to explore the solution to a practical problem [using Airway Pressure Release Ventilation (APRV) for mechanically ventilating adult patients with ARDS]. Strategies such as silent ideation and argumentative dialectics were employed to co-create knowledge. Results: The workshops demonstrated the effectiveness of collaborative engagement in generating actionable solutions and addressing ethical tensions through a focus on authenticity. A draft document [clinical pathway (CP)] was developed, showcasing the workshop’s capacity for structured co-creation and qualitative data collection. Conclusion: Aligning pragmatic assumptions with the notion of authenticity mitigated ethical tensions and enhanced the integrity of the data collection process. Workshops as research methodology offer a dynamic approach to addressing complex problems in practice-oriented fields, creating opportunities for collaboration and actionable outcomes.

Revolutionizing Mechanical Ventilation: Latest Advances and Practical Applications of Airway Pressure Release Ventilation.

Comparison of early and late time-controlled adaptive ventilation on pulmonary gas exchange in anesthetized horses.

IntroductionAPRV-TCAV(Habashi) is mechanistic approach in improvement of alveolar recruitment. It causes reduction in alveolar and alveolar duct micro strain and stress raisers, reduction in alveolar Vt. Time is critical component in determining alveolar inflation and deflation during each mechanical breath.1Primary ObjectiveTo assess the changes in Oxygenation Index (OI) at multiple time pointsTo analyze the evolution of Tidal Volume (Vt) and Inspiratory Pressure (P high) settingsSecondary ObjectiveTo compare mortality rates between pulmonary and extrapulmonary ARDSTo assess occurrence of hemodynamic instability after the initiation of APRVTo evaluate relationship between spontaneous breathing and sedation requirementsTo monitor air leaks (e.g pneumothorax, pneumomediastinum, subcutaneous emphysema) after APRV initiation.To identify and analyze the factors associated with failure of APRVMaterials and methodsIt was a single Centre Retrospective Observational study carried out in PICU at RCH, Bangalore over a period of 25 months.Inclusion criteriaChildren 1-18 years, with ARDS, as defined by the PALICC2 criteria started on APRV mode of mechanical ventilation.Exclusion criteriaPreemptive APRV in Dengue: Children with dengue receiving transfusions or in leaking phase, before developing hypoxiaSevere Right Ventricular Dysfunction & Pulmonary HypertensionRaised Intracranial Pressure, Refractory Shock, Neuromuscular disorderMethodologya In Children with ARDS who were started on APRV- Habashi's TCAV protocolb P High, T High, T Low, Fio2, Prior conventional setting (If rescue mode) minute ventilation, PaO2, PCo2, Tidal value were enteredc Oxygenation Index and Dead space fraction were calculatedd VIS Score, Sedation used and dose, hemodynamic parameters were noted.e Time Points for Measurement: Baseline, Subsequent Time Points were at 6, 12, 24, 48, and 72 hours post-APRV initiation.Statistical testsDescriptives, chi square tests, repeated variables ANOVA.Results48 patients were started on APRV. 62%(30/48) of them had pulmonary ARDS and 37.5% (18/48) had extrapulmonary ARDS. 25%(12/48) had severe ARDS. Among 17 patients in whom APRV was initiated as rescue mode, 12(70%) had pulmonary ARDS. Among them, mean P Plat was 21(18-27), Mean PEEP was 8(7-15)and mean FiO2 was 67.7(60-100%). Patients with Mild to moderate ARDS, TV at initiation of APRV was 6.07 mL/kg (4-8) compared to 4.4 mL/kg (3-6) in severe ARDS. At extubation in Mild to moderate ARDS, TV was 7.5 mL/kg(4.2-12) and in severe ARDS it was 7.06 mL/kg (3.5-12) along with increase in Minute Ventilation. Consistent reduction in P High(21->17) (p0.00) and OI (20 to 9) were noted, which were statistically significant(p<0.000). 7 (18%) were proned. 5(13%) needed HFOV. Sedation requirement decreased over time and spontaneous breathing was allowed by 12 hrs. 13(27%) died, all showed improvement in OI over time. Cause of death were due to non pulmonary reasons(MODS and complications).DiscussionConsistent improvement in Vt and MV with decreasing Phigh suggests lung recruitment over time. Improvement in OI and reduction in dead space fraction also suggest lung recruitment. Reduction in sedation and spontaneous breathing suggest reduction in asynchrony.

The Use of Airway Pressure Release Ventilation in a Patient With Severe Respiratory Alkalosis Following Intubation

Background Airway Pressure Release Ventilation (APRV), particularly with the Time-Controlled Adaptive Ventilation (TCAV) protocol, is known to improve oxygenation and respiratory mechanics. However, its role in managing refractory hypercapnia remains underexplored. This case report highlights APRV with TCAV as a potential strategy to tackle refractory hypercapnia. Case Report A 43-year-old woman with acute hypoxic and hypercapnic respiratory failure was admitted to our intensive care unit. Over the first 24 hours of management via conventional ventilation modes, she progressed to refractory hypercapnia, leading us to initiate modified APRV settings with TCAV protocol on the Puritan Bennett 980 ventilator (PB 980). This intervention led to rapid improvement in PaCO2, successful transition to PSV, and eventual liberation. Discussion Our literature review revealed limited research on the use of higher controlled respiratory rates in APRV with TCAV. This case demonstrates the potential of this approach, emphasizing the importance of adhering to TCAV principles while optimizing respiratory rate settings. Additionally, we provide insights into APRV titration on the PB 980. Conclusion This report supports the use of APRV with higher controlled respiratory rates, adhering to TCAV protocols, as an effective strategy for managing refractory hypercapnia. Further research is warranted to establish evidence-based guidelines. Keywords: CPAP, Time-Controlled Adaptive Ventilation (TCAV), Refractory Hypercapnia, Ventilation Strategies, Airway Pressure Release Ventilation (APRV)

Pediatric acute respiratory distress syndrome (PARDS) has a mortality rate of up to 75%, which can be up to 90% in high-risk patients. Even with the use of advanced ventilation strategies, mortality remains unacceptably high at 40%. Airway pressure release ventilation (APRV) mode is a new strategy in PARDS. Our aim was to evaluate whether use of APRV mode in severe PARDS was associated with reduced hospital mortality compared to other modes of ventilation. This was a retrospective comparative study using data from case files in a pediatric intensive care unit of a university-affiliated tertiary-care hospital. The study period (January 2014 to December 2019) covered three years before routine use of APRV mode to three years after its implementation. We compared severe PARDS patients in two groups: The APRV group (who received APRV as rescue therapy after failing protective ventilation); and The Non-APRV group, who received other modes of ventilation. A total of 24 patients in each group were analyzed. Overall in-hospital mortality in the APRV group was 79% versus 91% in the Non-APRV group. In-hospital mortality was significantly lower in the APRV group (univariate analysis: hazard ratio [HR], 0.27; 95% CI, 0.14-0.52; P=0.001 and multivariate analysis: HR, 0.03; 95% CI, 0.005-0.17; P=0.001). Survival times were significantly longer in the APRV group (median time to death: 7.5 days in APRV vs. 4.3 days in non-APRV; P=0.001). Use of rescue APRV mode in severe PARDS may yield lower mortality rates and longer survival times.

Background: Airway Pressure Release Ventilation (APRV) is an alternate mode of ventilation in acute respiratory failure (ARF), but there is inconsistent data to support its use over other modes of ventilation. Because of increased intrathoracic pressure for most of the respiratory cycle, a negative impact of APRV on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) has been hypothesized. We evaluated the effects of APRV ventilation, with particular attention to ICP, CPP and ICP-directed therapy, in a real-world cohort of neuro-ICU patients. Methods: Retrospective single-center analysis from January 2021 to December 2023 of neurosurgical ICU patients with ICP monitoring. APRV was used as a rescue mode at the physician's discretion when the Horovitz index (PaO2/FIO2 ratio) fell below 150 despite optimized conventional ventilation. Results: Between 2021 and 2023, APRV was utilized in 29 patients undergoing a total of 60 episodes. Forty patients (66.7%) were female, median age was 49.5 (Q1 34; Q3 61.25) years.After transition to APRV, mean FiO2 decreased by 4.3% (t = 3.5, p < .001) and mean PaO2 increased by 22.7 mm Hg (t = 4.2, p < .001). The Horovitz index improved by 44.6 mm Hg (t = 4.9, p < .001). Mean compliance did not differ after transition to APRV (-1.5 ml/mbar, t = -0.9, p = .4).During the APRV episode, mean ICP was 1.2 mm Hg lower (t = 2.6, p = .01), while mean CPP was 1.6 mm Hg higher (t = -0.9, p = .4) and the intensity of ICP-directed therapy (TIL) was significantly lower (X2 = 92.771, p < .001). Conclusion: APRV was hemodynamically tolerated in 29 out of 33 patients, and was safe with regard to ICP, CPP, and the intensity of ICP-directed therapy. Oxygenation was increased by APRV. 4 out of 33 patients would not tolerate APRV for hemodynamic reasons, APRV therefore was stopped immediately.

BackgroundAPRV has been used for ARDS in the past. Little is known about the risk of ventilator- induced lung- injury (VILI) in APRV vs. BIPAP in the management of in COVID19-associated ARDS (CARDS). This study aimed to compare transpulmonary pressures (TPP) in APRV vs. BIPAP in CARDS in regard to lung protective ventilator settings.MethodsThis retrospective, monocentric cohort study (ethical approval: 21-1553) assessed all adult ICU- patients with CARDS who were ventilated with BIPAP vs. APRV and monitored with TPP from 03/2020 to 10/2021. Ventilator-settings / -pressures, TPP, hemodynamic and arterial blood gas parameters were compared in both modes.Results20 non- spontaneously breathing patients could be included in the study: Median TPPendexpiratory was lower / negative in APRV (-1.20mbar; IQR − 4.88 / +4.53) vs. positive in BIPAP (+ 3.4mbar; IQR + 1.95 / +8.57; p < .01). Median TPPendinspiratory did not differ. In APRV, mean tidal- volume per body- weight (7.05 ± 1.28 vs. 5.03 ± 0.77 ml; p < .01) and mean airway- pressure (27.08 ± 1.67 vs. 22.68 ± 2.62mbar; p < .01) were higher. There was no difference in PEEP, peak-, plateau- or driving- pressure, compliance, oxygenation and CO2- removal between both modes.ConclusionDespite higher tidal- volumes / airway-pressures in APRV vs. BIPAP, TPPendinspiratory was not increased. However, in APRV median TPPendexpiratory was negative indicating an elevated risk of occult atelectasis in APRV- mode in CARDS. Therefore, TPP- monitoring could be a useful tool for monitoring a safe application of APRV- mode in CARDS.

Physiological Comparison of Airway Pressure Release Ventilation and Low Tidal Volume Ventilation in Acute Respiratory Distress Syndrome: A Randomized Controlled Trial

629 Limits of airway pressure release ventilation (APRV) as a mode of non-invasive ventilation using the RAM Cannula

There is a limited data examining the practice of using the airway pressure release ventilation mode for patients with acute respiratory distress syndrome among respiratory therapists. To evaluate the current practice and barriers when using airway pressure release ventilation mode in the management of patients with acute respiratory distress syndrome. A cross-sectional online survey was disseminated between November 2022 and April 2023 to respiratory therapists in Saudi Arabia. Descriptive statistics were used to analyze the respondents' characteristics. Overall, 802 respiratory therapists (male: 59.60%) completed the survey. Five hundred nineteen (64.71%) did not receive training on airway pressure release ventilation mode. Moreover, 325 (40.52%) and 391 (48.75%) did not know if airway pressure release ventilation was used at their hospitals and if the mode was managed via protocol with acute respiratory distress syndrome patients. Of the participants, 276 (34.41%) reported that plateau pressure should be used as a target when setting P-high initially, while 427 (53.24%) believed that the initial P-low should be equal to 0 cmH2O. Moreover, 468 (58.36%) believed that the initial T-high should be between 4 and 6 s, while 548 (68.33%) believed the initial T-low should be a set time (between 0.4 and 0.8) seconds. The most appropriate intervention to improve ventilation and oxygenation was to increase the P-high, which was reported by 370 (46.14%) and 326 (40.65%) respiratory therapists, respectively. Inadequate training was the most common barrier (678, 84.54%) to airway pressure release ventilation implementation. Airway pressure release ventilation management varies between respiratory therapists which may be due to inadequate training and the absence of protocols.

BackgroundPostoperative negative pressure pulmonary edema (NPPE) can occur in any patient undergoing general anesthesia. There are several risk factors for it, especially postoperative laryngospasm. The disease is usually benign and quickly reversible. In our case the severity and need for advanced critical care therapy was unusual.CaseWe report a severe case of postoperative negative pressure pulmonary edema in a 62-year-old male patient undergoing elective right-sided retroperitoneoscopic adrenalectomy. The patient developed a severe case of acute respiratory distress syndrome (ARDS) after postoperative laryngospasm, possibly in conjunction with a suspected anaphylactic reaction. The patient was consequently treated with a combination of invasive airway pressure release ventilation (APRV) and a prone positioning regimen. After drastic improvement in respiratory function, the patient was discharged from the intensive care unit after 10 days and from the hospital after 14 days.ConclusionNPPE is a rare but relevant complication of anesthesia and laryngospasm. The disease can basically occur in any patient undergoing general anesthesia and therefore should be considered.

BackgroundAirway pressure release ventilation (APRV) has been shown to be protective against atelectrauma if expirations are brief. We hypothesize that this is protective because epithelial surfaces are not given enough time to come together and adhere during expiration, thereby avoiding their highly damaging forced separation during inspiration.MethodsWe investigated this hypothesis in a porcine model of ARDS induced by Tween lavage. Animals were ventilated with APRV in 4 groups based on whether inspiratory pressure was 28 or 40 cmH2O, and whether expiration was terminated when end-expiratory flow reached either 75% (a shorter expiration) or 25% (a longer expiration) of its initial peak value. A mathematical model of respiratory system mechanics that included a volume-dependent elastance term characterized by the parameter E2 was fit to airway pressure-flow data obtained each hour for 6 h post-Tween injury during both expiration and inspiration. We also measured respiratory system impedance between 5 and 19 Hz continuously through inspiration at the same time points from which we derived a time-course for respiratory system resistance (Rrs).ResultsE2during both expiration and inspiration was significantly different between the two longer expiration versus the two shorter expiration groups (ANOVA, p < 0.001). We found that E2 was most depressed during inspiration in the higher-pressure group receiving the longer expiration, suggesting that E2 reflects a balance between strain stiffening of the lung parenchyma and ongoing recruitment as lung volume increases. We also found in this group that Rrs increased progressively during the first 0.5 s of inspiration and then began to decrease again as inspiration continued, which we interpret as corresponding to the point when continuing derecruitment was reversed by progressive lung inflation.ConclusionsThese findings support the hypothesis that sufficiently short expiratory durations protect against atelectrauma because they do not give derecruitment enough time to manifest. This suggests a means for the personalized adjustment of mechanical ventilation.