Volume Assured Pressure Support Research Articles

Adaptive non‐invasive ventilation treatment for sleep Apnea

AbstractThe purpose of this study was to investigate the effectiveness of two non‐invasive mechanical ventilation (NIV) modalities to treat sleep apnea: (1) Average Volume Assured Pressure Support (AVAPS) NIV, and (2) Pressure Support (PS) NIV with Continuously Calculated Average Required Ventilation (CCARV). Two detailed (previously developed and tested) simulation models were used to assess the effectiveness of the NIV modalities. One simulated subjects without chronic obstructive pulmonary disease (COPD), and the other simulated patients with COPD. Sleep apnea was simulated in each model (COPD and Non‐COPD), and the ability of each NIV modality to normalize breathing was measured. In both NIV modalities, a low level continuous positive airway pressure was used and a backup respiratory rate was added to the algorithm in order to minimize the respiratory work rate. Both modalities could help normalize breathing in response to an episode of sleep apnea within about 5 min (during which time blood gases were within safe limits). AVAPS NIV and PS NIV with CCARV have potential value to be used for treatment of sleep apnea. Clinical evaluations are needed to fully assess the effectiveness of these NIV modalities.

Development of a non-invasive ventilator for emergency and beyond

The SARS-CoV-2 pandemic led to the development and implementation of emergency ventilators owing to the shortage of ventilators globally. Using invasive ventilators for patient intubation has medical experts concerned about increasing mortality. Early intervention with oxygen and respiratory therapy reduces the need for intubation, increases survival rates, and reduces the stress of critical care ventilators in hospitals. This study explores the capabilities of an easy-to-build and accessible non-invasive ventilator during an emergency and the practical implementation of the ventilator beyond the scope of the emergency. The proposed system consists of a high-pressure turbine integrated with a microcontroller and pressure and flow sensors assembled in a portable design. The non-invasive pressure support system is tested with a single-chamber high-precision lung simulator capable of simulating multiple lung diseases. The system is operated in a spontaneous pressure support mode as a Bi-level Ventilator for varying degrees of pressure level and lung conditions. The proposed study implements two most commonly adapted non-invasive patient circuits, i.e., single passive limb leak circuit and single limb active circuit. Both circuits are tested with and without leakage compensation. Two clinically accepted ventilation modes, i.e., pressure support and volume-assured pressure support ventilation, are presented. The results demonstrate the feasibility of using this type of device for non-invasive respiratory support and highlight the need for further testing to assess its safety and effectiveness in various clinical settings.

P010 Delivery of volume assured pressure support (VAPS) through tracheostomy in paediatric patients

Abstract INTRODUCTION Volume assured pressure support (VAPS) allows the ventilator to deliver a constant pre-set tidal volume or alveolar ventilation by automatically adjusting the inspiratory pressures within a set range, providing targeted pressure support. Data on its use in children are limited. We describe a series of four children effectively and safely ventilated using VAPS mode through tracheostomy. METHODS Retrospective review of patient notes. PROGRESS TO DATE Four paediatric patients were identified in our cohort who were successfully and safely ventilated using the VAPS mode through tracheostomy. The patients were between 6-14 years of age inclusive, with four differing underlying disease processes – Prader-Willi syndrome, congenital central hypoventilation syndrome, Guillain-Barré syndrome and Moebius-type syndrome. INTENDED OUTCOME AND IMPACT Whilst there have been previous paediatric case reports and case series which have demonstrated efficacy of VAPS mode used non-invasively, the use of VAPS mode to provide effective and safe ventilation through tracheostomy in children has been described in only one recent case series. The advantages of its use over conventional bilevel positive airway pressure support include its ability to compensate for changes in tidal volume, which can occur with changes in lung compliance and during different stages of sleep. This case series highlights safe and effective use of VAPS mode in children with tracheostomy.

Volume assured pressure support mode use for non-invasive ventilation in pediatrics.

There has been increasing interest in utilizing volume assured pressure support (VAPS) modes of ventilation for children, which historically had only been favored in adult populations. In addition to patients with obesity hypoventilation syndrome, newer pediatric populations for which it has recently been prescribed include congenital central hypoventilation syndrome and children with neuromuscular disease such as Duchenne muscular dystrophy and spinal muscular atrophy. Given its expanding use in pediatrics, greater familiarity with VAPS is essential for pediatric pulmonologists and sleep physicians. This review article will highlight methods of initiation for this mode, specific ventilator settings, discussion of suitable pediatric patient populations, ventilator titrations via formal polysomnograms and detailed ventilator data downloads specific interpretation. Finally, common challenges to be aware of and how to troubleshoot relevant machine alarms will be reviewed.

Effect of Non-Invasive Mechanical Ventilation with Average Volume Assured Pressure Support (AVAPS) in Patients with Chronic Obstructive Pulmonary Disease with Acute Exacerbation

Background: Patients with acute respiratory failure have traditionally been evaluated for non-invasive mechanical ventilation (NIV) based on clinical evaluation and changes in blood gases, with NIV support pressures manually adjusted by an operator. Bilevel positive airway pressure-spontaneous/timed (BiPAP S/T) with average volume assured pressure support (AVAPS) uses a fixed tidal volume that automatically adapts to a patient's needs. Objective: To see the effective of non-invasive mechanical ventilation with average volume assured pressure support (AVAPS) in patients with chronic obstructive pulmonary disease with acute exacerbation. Materials and Methods: This single-center prospective study was carried out at the Gazi Medical College (GMC), Khulna, Bangladesh, in the department of medicine. The research's participants were all admitted between December 1, 2021, and January 1, 2023. The trial included all patients with acute exacerbations of chronic obstructive pulmonary disease. Age, gender, and disease severity were determined using the APACHE II scoring system. A structured proforma was used to collect data. The percentage and absolute number were used to express all category data. All numerical continuous data were reported as mean standard deviation. SPSS version 23 was used to analyze the data. All tests were evaluated using a 95% confidence interval, and a P value of 0.05 was deemed significant. Results: The mean MBS, NRS, dyspnea/comfort scale, respiration rates, systolic blood pressure, and diastolic blood pressure- post treatment were statistically significant (p <0.05) when compared to pretreatment in the BiPAP S/T with AVAPS group. Mean PaCO2, MBS, NRS, dyspnea/comfort scale, heart rate, respiration rates, and systolic blood pressure- post treatment were statistically significant (p <0.05) when compared to pretreatment in the BiPAP S/T group. Conclusion: BiPAP S/T with AVAPS promotes a quicker return to awareness in patients with chronic .......

Average Volume-assured Pressure Support as Rescue Therapy after CPAP Failure in Pediatric Obstructive Sleep Apnea: A Retrospective Case Series Study.

Continuous positive airway pressure (CPAP) is frequently prescribed for patients with residual obstructive sleep apnea (OSA) following adenotonsillectomy. The goal was to examine the efficacy of noninvasive ventilation with average volume-assured pressure support (AVAPS) as a potential option for children with failed CPAP titration. In a single-center retrospective study, we included children aged 1-17 years, with polysomnographically confirmed OSA who underwent AVAPS titration following failed CPAP titration. In addition to describing the clinical characteristics of the included patients, we compared polysomnographic parameters before and after AVAPS. Nine patients met the inclusion criteria; out of them, 8 (89%) were males with an age range of 6.7 ± 3.9 years and a body mass index percentile of 81.0 ± 28.9. Reasons for failed CPAP titration were: 3 (33%) patients due to inability to control apnea-hypopnea index (AHI), 3 (33%) patients due to sleep-related hypoventilation, 2 (22%) patients due to treatment-emergent central sleep apnea, and 1 (11%) patient due to intolerance to CPAP. AVAPS resulted in a greater reduction in AHI than CPAP (reduction following CPAP = 24.6 ± 29.3, reduction following AVAPS = 42.5 ± 37.6, p = 0.008). All patients had resolution of the problems which caused CPAP failure. In this case a series of children with OSA and with failed CPAP titration, AVAPS resulted in a greater reduction in AHI compared with CPAP as well as resolution of the problems which caused CPAP failure.

Moving toward standardization: physician reporting of sleep studies.

Lastra AC, Ingram D, Park J, etal. Moving toward standardization: physician reporting of sleep studies. J Clin Sleep Med. 2023;19(3):595-603.

Role of Average Volume Assured Pressure Support Mode (AVAPS) in the Management of Acute Exacerbation of Chronic Obstructive Pulmonary Disease With Type 2 Respiratory Failure.

Background Non-invasive ventilation (NIV) is a well-established approach in the treatment of acute exacerbation of chronic obstructive pulmonary disease (COPD) with type 2 respiratory failure. Average volume-assured pressure support (AVAPS) mode integrates the characteristics of both volume and pressure-controlled modes of NIV. In bilevel positive airway pressure (BiPAP) mode, volume is the dependent variable, whereas in AVAPS mode, pressure is the dependent variable. In this study, we aimed to compare the role of AVAPS mode with BiPAP spontaneous/timed (S/T) mode for the management of patients with acute exacerbation of COPD with type 2 respiratory failure. Methodology A hospital-based comparative and analytical study was carried out on 100 patients with acute exacerbation of COPD with type 2 respiratory failure admitted to respiratory disease hospital, Sardar Patel Medical College, Bikaner (Rajasthan, India). Patients were randomly divided into two groups of 50 patients each. Group A patients were treated with AVAPS mode and group B patients with BiPAP (S/T) mode. Arterial blood gases, average duration of hospital stay, and need for invasive mechanical ventilation were compared between the two groups. Results There was a statistically significant difference in favor of group A in terms of improvement in pH andpCO2as compared to group B at 6 h (pH, p=0.027; pCO2, p=0.012) and 24 h (pH, p=0.032; pCO2, p=0.013). The duration of hospital stay was found to be lower in group A(p=0.003). However, no significant difference was found in terms of need for invasive mechanical ventilation between both groups (p=0.338). Conclusion Application of AVAPS mode results inmore rapid and steady improvement inpatients of COPD as compared to BiPAP (S/T) mode. Thus, managementthrough non-invasive ventilation AVAPS mode should be considered inpatients with acute exacerbation of COPD with type 2 respiratory failure.

Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support versus BiPAP S/T in De Novo Hypoxemic Respiratory Failure.

Background Bilevel positive airway pressure in spontaneous/time and average volume-assured pressure support (BiPAP·S/T–AVAPS) could maintain an adequate tidal volume by reducing the patient's inspiratory effort; however, this ventilatory strategy has not been compared with other ventilatory modes, especially the conventional BiPAP S/T mode, when noninvasive mechanical ventilation (NIMV) is used. The primary objective of this study was to determine the rate of success and failure of the use of BiPAP·S/T-AVAPS versus BiPAP·S/T alone in patients with mild-to-moderate “de novo” hypoxemic respiratory failure. Methods This was a matched-cohort study. Subjects with mild-to-moderate de novo hypoxemic respiratory failure were divided into two groups according to the ventilatory strategy used. The subjects in the BiPAP·S/T group were paired with those in the BiPAP·S/T-AVAPS group. Results A total of 58 subjects were studied. Twenty-nine subjects in the BiPAP·S/T group were paired with 29 subjects in the BiPAP·S/T-AVAPS group. Twenty patients (34.5%) presented with “failure of NIMV,” while 38 (65.5%) patients did not. In addition, 13 (22.4%) patients died, while 45 (77.6%) recovered. No differences were found in the percentage of intubation (P=0.44) and mortality (P=0.1). Conclusion The BiPAP S/T-AVAPS ventilator mode was not superior to the BiPAP·S/T mode. A high mortality rate was observed in patients with NIMV failure in both modes. This trial is registered with https://doi.org/10.1186/ISRCTN17904857.

Average volume-assured pressure support for patients with obstructive sleep apnea with failed CPAP titration.

ObjectivesObstructive sleep apnea (OSA) is a common disease, often treated using continuous positive airway pressure (CPAP) therapy. In many cases, patients fail a CPAP titration study due to inadequate control of the apnea-hypopnea index (AHI, events/hour) or due to treatment-emergent central sleep apnea (TE-CSA). We report our experience using a mode of non-invasive ventilation for alternative treatment of these patients.Material and MethodsWe reviewed records of adults who had OSA with AHI≥15 diagnosed on polysomnography (PSG) with failed CPAP titration and in whom titrations with average volume-assured pressure support (AVAPS) with auto-titrating expiratory positive airway pressure were performed.ResultsForty-five patients, age 57.9±13.1 y, 26 males, body mass index (BMI) 40.2±8.7kg/m2. Reasons for CPAP titration failure included: TE-CSA (25, 55.6%) and inadequate control of AHI at maximum CPAP of 20cm H2O (20, 44.4%). Changes noted from baseline PSG to AVAPS titration: AHI: 65.3±29.3 decreased to 22.3±16.1 (p<0.001). Median time SpO2 ≤88%: 63.7 to 6.9min (p<0.001). In 16 patients the AHI was reduced to <15 and in 16 additional patients the AHI was reduced to <30. Improvement in AHI was not related to gender, age, or opioid use, but was correlated with BMI: ∆AHI=12.2 - (1.4 * BMI); p=0.05. AVAPS resulted in improved sleep architecture: median N3 sleep increased: 1.4% to 19.6% total sleep time (TST) (p<0.001), and median R sleep increased: 6.4% to 13.6% TST (p<0.01).DiscussionFor patients with OSA for whom CPAP titration failed, titration with AVAPS may be an effective treatment.

0529 Average volume-assured pressure support as rescue therapy after CPAP failure in pediatric obstructive sleep apnea

Abstract Introduction Average volume-assured pressure support with autotitrating EPAP (AVAPS-AE) is an automatically titrating mode of noninvasive ventilation (NIV) which provides a targeted tidal volume through adjustment of inspiratory pressures within a set range. In pediatric obstructive sleep apnea (OSA), adenotonsillectomy (AT) is often the first-line treatment and CPAP is often poorly tolerated as an alternative. We aimed to evaluate the efficacy of AVAPS as a potential option for children in whom CPAP titration is unsuccessful. Methods Retrospective review of records of children diagnosed with OSA with failed CPAP titration and in whom an in-laboratory AVAPS titration was performed. Results A total of 9 patients with OSA (8 male, age (95% CI) = 6.7 ± 2.6, BMI percentile (95% CI) = 81.0 ± 18.9) were identified. Of these patients, 6 had prior AT. All 9 patients had failed CPAP titration prior to AVAPS titration: 3 failed due to inability to control the apnea-hypopnea index (AHI, events/hour), 2 due to persistent hypercapnia, 2 due to treatment-emergent central sleep apneas, and 2 due to pressure intolerance. All 9 patients showed improvement in AHI following AVAPS titration (mean change = -17.9, 95% CI = 17.9 ± 9.5) as well as improvement in AHI from initial PSG to AVAPS titration (mean change = -42.5, 95% CI = 42.5 ±24.6). 7 patients had reduction in total sleep time with oximetry recording below 90% (T&amp;lt;90) from CPAP to AVAPS titration (mean change = -4.7 minutes, 95% CI = 4.7 ± 14.7), while 8 patients had reduction in T&amp;lt;90 from initial PSG to AVAPS titration (mean change = -14.0 minutes, 95% CI = 14.0 ±24.5). 7 patients had increase in REM sleep from CPAP to AVAPS titration (mean change = +15.9 minutes, 95% CI = 15.9 ±18.3), while 6 patients had increase in REM sleep from initial PSG to AVAPS titration (mean change = +7.7 minutes, 95% CI = 7.7 ±26.6). Conclusion In this case series of children with OSA and with failed CPAP titration, AVAPS is an effective treatment modality. Support (If Any)

0859 AVAPS to the rescue: A case of severe obstructive sleep apnea with treatment resistant to UPPP and CPAP in a pediatric patient with Prader-Willi syndrome

Abstract Introduction Prader-Willi syndrome (PWS) has a prevalence of 1/10,000 to 1/30000 and is the most common syndromic form of obesity. Prader-Willi syndrome is defined by a multitude of features that develop from early childhood to adolescents, but one of the primary developments is obesity in the setting of hyperphagia during early childhood. Due to the development of obesity, there is a high prevalence of obstructive sleep apnea (OSA) among PWS patients. Report of Cases: A 6-year-old boy with PWS with a 2-year history of loud snoring underwent polysomnography (PSG) which showed severe OSA with Apnea-Hypopnea Index (AHI, events/h) 133.7. The patient underwent surgical intervention with a combined uvulopalatopharyngoplasty and adenotonsillectomy and a follow up PSG showed a residual AHI of 37. On CPAP titration the AHI improved to 1.2 with CPAP 14 cm H2O and the patient was discharged on home nasal CPAP. Over the next several years, the patient had suboptimal CPAP compliance. At 11 years of age, the patient was admitted to the intensive care unit (ICU) with volume overload –with a normal cardiac workup- and respiratory failure requiring high flow nasal cannula oxygen. Venous blood gas (VBG) showed pH 7.34 and severe hypercapnia with pCO2 73 mmHg c/w obesity hypoventilation syndrome (OHS). The patient was started on CPAP then changed to bilevel PAP ST with supplemental oxygen. Due to persistent hypercapnia in the high 60s noninvasive ventilation (NIV) was switched to Average Volume-assured Pressure Support with auto titrating EPAP (AVAPS-AE) with significant improvement in hypercapnia and overall tolerance. Discharge VBG showed pH 7.35 and PCO2 56 mm Hg. The patient was discharged home, is doing well and has avoided readmission for at least 6 months. Conclusion This case highlights the potential for newer modes of noninvasive ventilation with autotitrating EPAP to treat severe OSA with OHS and hypercapnic respiratory failure in patients with PWS and other conditions. With the growing obesity epidemic, rates of treatment failures with CPAP and traditional bilevel PAP therapy may increase and consideration of alternative modes of NIV therapy should be considered. Support (If Any)

0837 Average Volume-Assured Pressure Support (AVAPS) after CPAP Failure in A Pediatric Patient with Severe Obstructive Sleep Apnea and Sleep-Related Hypoventilation

Abstract Introduction Obstructive sleep apnea (OSA) has become an increasingly pervasive sleep disorder in the pediatric population. Current mainstream treatments include adenotonsillectomy and positive airway pressure therapy. Average volume-assured pressure support (AVAPS) is a relatively new mode of non-invasive ventilation, which has been increasingly used in the treatment of respiratory failure and hypoventilation syndromes. Here we present a case of a pediatric patient with severe OSA and sleep-related hypoventilation who was successfully treated with AVAPS after failure of CPAP therapy. Report of Cases: A four year old boy with history of severe OSA, severe obesity, asthma, and allergic rhinitis underwent polysomnography one year after adenotonsillectomy and nasal turbinate reduction due to continued symptoms of sleep-disordered breathing. Results showed elevated residual apnea-hypopnea index (AHI = 30.4 events/hour), sleep-related hypoventilation (T ETCO2≥50 = 228.3 minutes), and sleep-related hypoxemia (T≤90% = 7 minutes). Therefore the patient underwent repeated adenotonsillectomy and turbinate reduction, with post-operative course complicated by pulmonary edema requiring intubation. He was extubated and weaned to nocturnal CPAP. Following discharge, CPAP titration failed to control AHI at maximal pressure (AHI 54.5 on 20 cm H2O, T≤90% = 15.3 minutes). The patient was then started on AVAPS with auto-titrating EPAP (AVAPS-AE, settings Pmax 20 cm H2O, PS 2-10 cm H2O, EPAP 5-10 cm H2O, RR auto, room air) with subsequent improvement of snoring and witnessed apneas, as well as reduction of daytime sleepiness. Afterwards, AVAPS-AE titration confirmed resolution of obstructive sleep apnea, sleep-related hypoxemia, and sleep-related hypoventilation (AHI = 2.5, T≤90% = 1.2 minutes, T ETCO2 ≥50 = 6.5 minutes.) The patient has since remained stable on AVAPS-AE until age ten, with the most recent AVAPS titration demonstrating continued resolution of sleep-disordered breathing. Conclusion AVAPS was an effective treatment for a pediatric patient with severe OSA and sleep-related hypoventilation who had failed CPAP therapy. Support (If Any) None.

Pediatric Average Volume Assured Pressure Support.

Average volume assured pressure support (AVAPS) is a modality of non-invasive ventilation that enables the machine to deliver a pre-set tidal volume by adjusting the inspiratory pressure support within a set range. Data on its use in the pediatric population are limited to case reports and single centre case series. This article reviews paediatric data on use of AVAPS and highlights the need for validation to help develop specific guidelines on use of AVAPS in children.

PAP therapy and readmission rates after in-hospital laboratory titration polysomnography in patients with hypoventilation.

Hypoventilation associated with sleep-disordered breathing in inpatients is associated with higher risk of morbidity, hospitalizations, and death. In-hospital titration polysomnography qualifies patients for positive airway pressure (PAP) therapy and optimizes settings, but impact is unknown. This study describes a process for in-hospital sleep testing and evaluates subsequent PAP adherence and readmission. A retrospective cohort of patients with hypoventilation and in-hospital titration polysomnography with available PAP data were analyzed to determine whether PAP adherence was associated with 90-day readmission. Absolute differences were obtained using logistic regression models. Models were adjusted for body mass index, age, and Elixhauser index. PAP adherence and nonadherence were defined as ≥ 4 and < 4 hours of daily average use prior to readmission or first 90 days postdischarge. Eighty-one patients, 50.6% male, with age (mean ± SD) 61.1 ± 13.5 years were included. Comorbid sleep disorders included 91.4% with obstructive sleep apnea and 23.5% with central sleep apnea. Twenty-eight of 52 (53.8%) nonadherent and 6 of 29 (20.7%) adherent patients had 90-day readmissions. Eleven (13.6%) patients (all nonadherent) were readmitted within 2 weeks of discharge. The adjusted model showed a 35.6% (95% confidence interval 15.9-55.2%) reduction in 90-day readmission in the adherent group compared with the nonadherent group (P = .004). Similar reductions in readmission were found with adherence of ≥ 50% and ≥ 70% of days ≥ 4 hours. Male sex, treatment with iVAPS (intelligent volume-assured pressure support), and highest CO2 ≥ 60 mmHg on polysomnography were associated with the largest differences in readmission rates between adherent and nonadherent patients. Adherence to optimized PAP therapy after in-hospital titration polysomnography in patients with hypoventilation may decrease readmissions. Johnson KG, Rastegar V, Scuderi N, Johnson DC, Visintainer P. PAP therapy and readmission rates after in-hospital laboratory titration polysomnography in patients with hypoventilation. J Clin Sleep Med. 2022;18(7):1739-1748.

Alveolar Ventilation-Targeted Versus Spontaneous/Timed Mode for Home Noninvasive Ventilation in Amyotrophic Lateral Sclerosis.

Home noninvasive ventilation (NIV) is increasingly used in amyotrophic lateral sclerosis (ALS) to improve symptoms and survival. Our primary objective was to compare intelligent volume-assured pressure support (iVAPS) versus spontaneous/timed (S/T) modes regarding time to first change in ventilator parameters and the number of interventions over 6 months in subjects with ALS in a respiratory therapist (RT)-led program. In this study, 30 subjects with ALS meeting criteria for NIV initiation were randomized to iVAPS or S/T. NIV was initiated using standardized protocols targeting optimal tidal volume and comfort in a daytime session. Download data were recorded at 1 week and 1 and 6 months. Any changes in ventilator parameters were recorded. Of the 30 subjects, 56.7% had bulbar onset ALS, 8 died, and 11 in each group completed the study. Median time to first parameter change was 33.5 (interquartile range [IQR] 7.7-96.0) d versus 41.0 (IQR 12.5-216.5) d for iVAPS versus S/T groups, respectively, (P = .48). The average number of RT interventions was similar between groups (1.1 ± 1.1 vs 0.9 ± 0.9 at 1 month, P = .72; 2.4 ± 2.1 vs 2.4 ± 2.3 at 6 months, P = .95, for iVAPS vs S/T, respectively). Adherence was significantly lower with iVAPS than S/T at 1 week but not at 1 or 6 months. Download parameters were similar between groups at 1 week and 6 months except for higher residual apnea-hypopnea index (AHI) and less spontaneously triggered breaths with iVAPS at 6 months. The time to first change of parameters and the number of interventions at 6 months from NIV initiation were similar for the iVAPS and S/T modes in subjects with ALS. With iVAPS, adherence was lower transiently at NIV initiation, and the residual AHI was higher at 6 months. Alveolar ventilation-targeted NIV may require a longer adaptation period and result in greater upper-airway instability predominantly in patients with bulbar ALS.

Comparison of Volume Support, Volume-Assured Pressure Support, and Spontaneous Modes in Postoperative Early Extubated Patients.

This study aimed to compare respiratorily, arterial blood gas (ABG), and hemodynamics parameters among patients undergoing surgery who were admitted to intensive care unit (ICU), using three ventilation modes, including volume-assured pressure support (VAPS), volume support (VS), and spontaneous modes. One hundred and thirty-two patients were randomly assigned into three groups of VAPS, VS, and spontaneous modes utilizing randomized block procedure. Patients were followed between 12 and 30 h until extubation. Respiratory parameters including; peak inspiratory pressure (PIP), static compliance, resistance, rapid shallow breathing index (RSBI), and P 0.1(P0.1 correlates with respiratory drive and is defined as the negative pressure measured at the airway opening 100 ms after the initiation of an inspiratory effort), along with ABG parameters including; pH level, PaCO2,HCO3,PaO2/FiO2 ratio, extra hydrogen ion, and hemodynamics parameters including; mean arterial blood pressure and heart rate were measured every 3 h and compared among groups. All studied parameters in three groups improved during the study. PIP, Resistance, PH, HCO3, extra hydrogen ion, PCo2, PaO2/FiO2 ratio, mean arterial blood pressure were similar among the three groups in most of the time points (P > 0.05). In most of the time points, RSBI (from 92.7 to 55.4), P 0.1 (from 6.8 to 1.7) in the VAPS group, static compliance (from 55.3 to 55.7) in the VS group, and heart rate (from 108.5 to 90.1) in spontaneous groups were significantly better than other modes (P < 0.05). Changes in RSBI, P 0.1, PCo2, HCO3, and heart rate during the study were significantly different among studied groups (P < 0.05). The length of stay in the ICU in patients who underwent VAPS was significantly shorter than the other modes. VAPS mode with better effects or at least as effective as VS and spontaneous modes could be select as the best mode of ventilation in postoperative early extubated patients admitted to ICU.

Intelligent volume assured pressure support (iVAPS) vs. spontaneous/timed mode as a weaning strategy for intubated COPD patients with acute exacerbation.

Noninvasive positive-pressure ventilation (NPPV) is applied to facilitate weaning process and decrease complications associated with prolonged intubation. Interest has emerged in using Intelligent Volume Assured Pressure Support (iVAPS) to facilitate earlier removal of an endotracheal tube. This study was conducted to compare the effectiveness of iVAPS versus standard Spontaneous/timed (S/T) mode in facilitating weaning process of mechanically ventilated chronic obstructive pulmonary disease (COPD) in acute exacerbation. In a prospective randomized study, 80 invasively ventilated COPD patients in acute exacerbations were extubated then immediate applicationof NPPV using either S/T mode (Group I) or iVAPS mode (Group II) was done. Clinical parameters (heart rate, respiratory rate, and arterial blood gas parameters at selected time intervals of treatment were recorded for both groups and analyzed. No significant differences were found between both groups regarding age, sex, mMRC dyspnea scale, CAT score and APACHE II score. Heart rate and mean arterial blood pressure in the two groups decreased with time, but no significant differences were found between the two groups. Likewise, there was no significant difference in RR between S/T and iVAPS groups. Regarding arterial blood gas analysis, there were no detectable differences in PaCO₂ level, PaO₂ level or oxygen saturation. The successful outcome was achieved in (82.5%) in the S/T group vs (80%) in the iVAPS group. The two modes achieved comparable levels of comfort as assessed by VAS and the total Mask Fitness Score. There was no statistically significant difference in reintubation, the duration of NPPV, duration of ICU stay or in mortality rate. iVAPS mode is as effective as fixed-pressure S/T mode in facilitating weaning of hypercapnic COPD patients.

APAP, BPAP, CPAP, and New Modes of Positive Airway Pressure Therapy.

Positive airway pressure (PAP) is the primary treatment of sleep-disordered breathing including obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. Just as clinicians use pharmacological mechanism of action and pharmacokinetic data to optimize medication therapy for an individual, understanding how PAP works and choosing the right mode and device are critical to optimizing therapy in an individual patient. The first section of this chapter will describe the technology inside PAP devices that is essential for understanding the algorithms used to control the airflow and pressure. The second section will review how different comfort settings including ramp and expiratory pressure relief and modes of PAP therapy including continuous positive airway pressure (CPAP), autotitrating CPAP, bilevel positive airway pressure, adaptive servoventilation, and volume-assured pressure support control the airflow and pressure. Proprietary algorithms from several different manufacturers are described. This chapter derives its descriptions of algorithms from multiple sources including literature review, manufacture publications and websites, patents, and peer-reviewed device comparisons and from personal communication with manufacturer representatives. Clinical considerations related to the technological aspects of the different algorithms and features will be reviewed.

Apnea-Hypopnea Index in Chronic Obstructive Pulmonary Disease Exacerbation Requiring Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support

Introduction This study intends to determine the Apnea-Hypopnea Index in patients hospitalized with acute hypercapnic respiratory failure from chronic obstructive pulmonary disease exacerbation, who require noninvasive ventilation with average volume-assured pressure support (AVAPS), as well as describes the clinical characteristics of these patients. Materials and Methods We designed a single-center prospective study. The coexistence of Apnea-Hypopnea Index and clinical, gasometric, spirometric, respiratory polygraphy, and ventilatory characteristics were determined. The clinical characteristics found were categorized and compared according to the Apnea-Hypopnea Index (AHI) < 5, AHI 5–15, and AHI >15. A p value <0.05 was considered statistically significant. Results During the study period, a total of 100 patients were admitted to the ICU with a diagnosis of acute hypercapnic respiratory failure due to COPD exacerbation. 72 patients presented with acute respiratory failure and fulfilled criteria for ventilatory support. Within them, 24 received invasive mechanical ventilation and 48 NIV. After applying the inclusion criteria for this study, 30 patients were eligible. An AHI >5 was present in 24 of the 30 patients recruited (80%). Neck circumference (cm), Epworth scale, and Mallampati score evidenced significant differences when compared to the patient's AHI <5, AHI 5–15, and AHI >15 (p < 0.05). Furthermore, patients with an AHI >5 had longer hospital admissions, prolonged periods on mechanical ventilation, and a higher percentage of intubation rates. Conclusion Apnea-Hypopnea Index and chronic obstructive pulmonary disease exacerbation are a frequent association found in patients with acute hypercapnic respiratory failure and COPD exacerbations that require NIV. This association could be a determining factor in the response to NIV, especially when AVAPS is used as a ventilatory strategy.