Inspiratory Positive Airway Pressure Research Articles

A comparison of two weaning strategies for non-invasive ventilation in chronic obstructive pulmonary disease patients with acute respiratory failure.

Non-Invasive Ventilation (NIV) is a crucial therapy for managing acute exacerbations of Chronic Obstructive Pulmonary Disease (COPD) with hypercapnic respiratory failure. Research has shown that NIV can decrease the rate of endotracheal intubation, length of hospital and Intensive Care Unit stays, and mortality. There are three main strategies for weaning patients off NIV: gradual reduction of NIV duration, gradual reduction of NIV pressure support, and immediate cessation of NIV. To compare the rate of successful withdrawal of COPD patients with acute hypercapnic respiratory failure, one group will use a stepwise reduction of duration of NIV, while the other group will use a stepwise reduction of pressure support. This study was a prospective observational study conducted at the Department of Pulmonary Medicine, Institute of Chest Diseases, Government Medical College, Kozhikode, over a period of 15months. The study population consisted of all COPD patients admitted to the Pulmonary Medicine ward or ICU with acute hypercapnic respiratory failure who were managed with non-invasive ventilation (NIV) without the need for invasive mechanical ventilation. Exclusions included patients requiring NIV for respiratory diseases other than COPD, those with significant comorbiditieslike acute left ventricular failure or fluid overload states as in chronic kidney disease, COVID-19 positive patients, patients on home NIV, patients who needed intubation early in treatment, and patients unwilling to participate in the study. The sample size was 140. Initial NIV settings and other management decisions prior to enrolment in the study were made by the treating physician according to standard protocols. Once weaning criteria were met (i.e., arterial pH > 7.35, SpO2 ≥ 90% at an FiO2 ≤ 50%, respiratory rate ≤ 25 breaths per minute, heart rate ≤ 120 beats per minute, systolic BP > 90mm Hg, and no signs of respiratory distress), patients were assigned to either group 1 or group 2 by purposive sampling. Group 1: stepwise reduction of duration of NIV use, with a reduction to 16h per day on day 1 of enrolment, 12h on day 2 (including 6-8h of nocturnal NIV), 6-8h on day 3, and NIV withdrawal on day 4. Group 2: stepwise reduction of pressure support, with pressure support reduced by 2-4cm every 4-6h until Inspiratory Positive Airway Pressure is < 8cm H2O and Expiratory Positive Airway Pressure is < 4cm H2O, followed by NIV withdrawal. The clinical outcome was classified as either improved or weaning failure. Improved was defined as an objective or subjective sense of improvement. Weaning failure was defined as the presence of any of the following: respiratory rate ≥ 25/minute or increase of ≥ 50% from baseline, heart rate ≥ 140/minute or increase of ≥ 20% from baseline, SpO2 ≤ 90% on FiO2 ≥ 50%, arterial pH ≤ 7.35, or respiratory distress. Data was collected using a pro forma that included demographic details, smoking status, GOLD COPD category, comorbidities, and vital signs. ABG parameters, NIV settings at the time of hospital admission, at the time of study enrolment, and 48h after weaning were also recorded. Independent sample t-test was used to test the statistical significance of the difference between means of variables between the two groups. Pearson Chi square test and Fisher's exact test were used to compare categorical variables between the groups. A p-value of < 0.05 was considered statistically significant. NIV was successfully withdrawn in 56/70 (80%) and 50/70 (71.4%) patients in Groups 1 and 2, respectively. This difference was not statistically significant. The length of hospital stay was longer in the stepwise reduction of duration group (Group 1), but this was not statistically significant. On comparison of two methods of NIV withdrawal, it was found that neither method is superior to the other in terms of weaning failure, intubation rates, and average length of hospital stay.

Virtual Learning Environment for Respiratory Support: A Simulation-Based Approach to Asynchronous Recognition and Correction of Ventilation Issues

The widespread utilization of medical ventilators, particularly during the COVID-19 pandemic, underscores the critical need for effective training in respiratory care. This paper introduces a web-based e-learning platform designed to simulate the complexities of mechanical ventilation systems, focusing on pressure mode control. The platform incorporates models representing various ventilation types, allowing users to manipulate crucial parameters such as IPAP (Inspiratory Positive Airway Pressure), EPAP (Expiratory Positive Airway Pressure), Ti (Inspiration Time), and BR (Breath Rate). By offering a realistic training environment, this system not only addresses the increasing demand for healthcare professional education but also facilitates effective monitoring and assessment of students’ progress by educators.

Profile of Sleep-related Breathing Disorders in Chronic Obstructive Pulmonary Disease-obstructive Sleep Apnea Overlap Syndrome

Introduction: Overlap syndrome (OS) is defined by the combined occurrence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD). Sleep-related breathing disorders (SRBDs) in OS can also manifest with central sleep apnea (CSA) and hypoventilation; besides OSA. Methods: This study was carried out to evaluate various SRBD in OS and its therapeutic implications patients having postbronchodilator obstruction in spirometry with respiratory symptoms were classified as COPD. Those found to have an apnea–hypopnea Index (AHI) &gt;5/h in polysomnography (PSG) were diagnosed as OS. All 37 patients diagnosed as OS underwent a subsequent positive airway pressure (PAP) titration. Results: On the evaluation of the SRBD, over half (51%) of the patients had OSA with no hypoventilation. More than one-third of the patients (35%) had associated hypoventilation with OSA, three patients had hypercapnic CSA, and two patients had hypocapnic CSA with Cheyne–Stokes breathing (CSA-CSB). The OSA group was easily titrated and corrected by CPAP therapy. OSA with hypoventilation group had underlying COPD with severe obstruction requiring bilevel PAP titration. Patients with CSA-CSB were elderly hypertensive patients with congestive heart failure who were corrected by PAP and optimization of cardiac medications. Patients with hypoventilation and hypercapnic CSA were most difficult to titrate and needed a backup rate along with PAP therapy for correction. On classifying patients on the basis of severity of OSA and COPD, there was no correlation found between AHI and forced expiratory volume 1 (FEV1). Patients with mild COPD with severe OSA were easily titrated with CPAP with a mean pressure of 8 cm H2 0. The most challenging cases were with severe COPD with severe OSA who required high pressures in both exhalation PAP and inspiratory PAP titration; two of such patients required backup rate by spontaneous/timed mode of PAP therapy. Conclusions: There are many profiles of SRBD in OS, and a detailed in-hospital PSG with a PAP titration can help in effectively managing the patients.

Hypothermia in preterm very-low-birthweight infants in a neonatal care unit of a tertiary hospital in Limpopo Province, South Africa

Background. Despite numerous interventions to prevent neonatal heat loss, preventing hypothermia after delivery continues to be aconcern in developing countries.Objective. To determine the prevalence of hypothermia and its risk factors among preterm very-low-birthweight infants admitted to the neonatal care unit (NCU) of a tertiary hospital in Limpopo Province, South Africa.Method. A retrospective study (January - July 2015) was undertaken to analyse data from the medical records of infants admitted tothe NCU of Mankweng Hospital. Hypothermia at admission was the major outcome and was defined as an axillary body temperature&lt;36.5°C. Maternal data collected were age, parity, use of antenatal corticosteroids, and mode of delivery, while neonatal data included sex, birthweight, gestational age, Apgar score, resuscitation at delivery, admission and discharge dates, length of stay, morbidity, interventions and infant outcomes.Results. A total of 252 neonate-and-mother pairs were included in the study, with hypothermia on admission being present in 35%of infants. Factors associated with hypothermia on admission include being born in the winter season, resuscitation at delivery, use ofsynchronised inspiratory positive airway pressure (SiPAP), respiratory distress syndrome and mortality.Conclusion. Hypothermia on admission in our study is relatively high and is associated with resuscitation in the delivery room, respiratory distress syndrome, use of SiPAP, winter season and neonatal mortality. Therefore maintaining infant temperature in the desired range of 36.5°C to 37.5°C after delivery, during transport and on NCU admission might improve neonatal outcomes.

Evaluation of Frequency and Risk Factors of Barotrauma among Patients with Severe Covid-19 Pneumonia Underwent Non-Invasive Ventilation in Afzalipour Hospital Kerman

Background: Acute respiratory distress syndrome (ARDS) following Covid-19 pneumo-nia is an important complication; using non-invasive ventilation (NIV) is one of the best supportive options available. In the recent Covid-19 pandemic, we have seen a significant increase in baro-trauma incidence following the use of NIV in patients with severe Covid-19 pneumonia. We aimed to identify the risk factors of barotrauma in patients with Covid-19 pneumonia under-going NIV. Methods: In this retrospective study, all adult patients with severe Covid-19 pneumonia who under-gone NIV and suffered from any form of barotrauma from July to September 2021 in Afzalipour Hospital, Kerman, Iran were evaluated. Laboratory tests and NIV machine settings were collected from patients' files. A chi-square test and an independent t-test were used for analytical statistics. Results: Twenty patients with barotrauma secondary to severe Covid-19 pneumonia were enrolled. The most common manifestation of barotrauma was pneumomediastinum in 19 patients (95%). No significant relationship was seen between the occurrence of barotrauma and Laboratory tests. The mean ± SD Inspiratory Positive Airway Pressure (IPAP) level in passed-away patients (17.8 ± 1.1) was significantly higher than in recovered patients (13.5 ± 0.5) (p = 0.04). Conclusion: According to the results of the study, using a low level of IPAP in the ventilator ma-chine settings of patients with barotrauma secondary to severe Covid-19 pneumonia will reduce the mortality rate.

Noninvasive Ventilation or CPAP for Postextubation Support in Small Infants.

Infants with a high risk of extubation failure are often treated with noninvasive ventilation (NIV) or CPAP, but data on the role of these support modalities following extubation are sparse. This report describes our experience using NIV or CPAP to support infants following extubation in our pediatric ICUs (PICUs). We performed a retrospective study of children < 10 kg receiving postextubation NIV or CPAP in our PICUs. Data on demographics, medical history, type of support, vital signs, pulse oximetry, near-infrared spectroscopy (NIRS), gas exchange, support settings, and re-intubation were extracted from the electronic medical record. Support was classified as prophylactic if planned before extubation and rescue if initiated within 24 h of extubation. We compared successfully extubated and re-intubated subjects using chi-square test for categorical variables and Mann-Whitney test for continuous variables. We studied 51 subjects, median age 44 (interquartile range 0.5-242) d and weight 3.7 (3-4.9) kg. There were no demographic differences between groups, except those re-intubated were more likely to have had cardiac surgery prior to admission (0% vs 14%, P = .040). NIV was used in 31 (61%) and CPAP in 20 (39%) subjects. Prophylactic support was initiated in 25 subjects (49%), whereas rescue support was needed in 26 subjects (51%). Twenty-two subjects (43%) required re-intubation. Re-intubation rate was higher for rescue support (58% vs 28%, P = .032). Subjects with a pH < 7.35 (4.3% vs 42.0%, P = .003) and lower somatic NIRS (39 [24-56] vs 62 [46-72], P = .02) were more likely to be re-intubated. The inspiratory positive airway pressure, expiratory positive airway pressure, and FIO2 were higher in subjects who required re-intubation. NIV or CPAP use was associated with a re-intubation rate of 43% in a heterogeneous sample of high-risk infants. Acidosis, cardiac surgery, higher FIO2 , lower somatic NIRS, higher support settings, and application of rescue support were associated with the need for re-intubation.

0953 A Novel Active Humidifier for Non-Invasive Ventilated Patients

Abstract Introduction The RespirAq® humidifier is a novel, active heated humidifier that humidifies without the need for additional water. Within milliseconds, the humidifier switches between a super-hydrophilic state to capture moisture during expiration, and a super-hydrophobic state, returning moisture during inspiration. The device delivers gases at 37°C/100% relative humidity to individuals requiring humidification, including those with tracheostomies. We demonstrated the device meets EN ISO 80601 2 74:2020 during bench testing. This study aimed to compare the performance of the novel humidifier with a heated humidifier - HH (MR850™ Fisher &amp; Paykel Healthcare) and a heat and moisture exchanger - HME (DAR™ Covidien) in healthy volunteers during non-invasive ventilation (NIV) using a non-vented full face mask. Methods Ten healthy volunteers were recruited. NIV was performed at different settings (inspiratory positive airway pressure (IPAP) range 5-20cmH20, expiratory positive airway pressure (EPAP) = 5cmH20) over a one-hour period. Humidity and temperature were collected continuously during the study. Results Sixty per cent of participants were female. Mean age of 35.6 ± 5.89 years (M±SD, n=10). Absolute humidity inside the face mask increased from 22.55 ± 2.41 mg/L without humidification to 30.18 ± 2.07 mg/L with an HME, and 39.09 ± 1.05 mg/L and 38.23 ± 1.78 mg/L when using a water-based heated humidifier and the novel humidifier, respectively. When comparing the performance of the humidification devices head-to-head, the two heated humidifiers significantly outperformed the HME (HME vs Novel = P &amp;lt; 0.0001, HME vs HH = p &amp;lt; 0.0001) and there was no significant difference seen between the two active humidifiers (p =0.2047). Conclusion Results show that the device meets the 12 mg/L absolute humidity established by the EN ISO 80601-2-74:2020 standards and that there is no significant difference in performance compared to traditional heated humidification. This suggests that the novel device can deliver the performance of a heater humidifier at the size, reliability and ease of use of a heat and moisture exchanger. Due to the mechanism of action, droplet/aerosol transmission of COVID-19 may also be mitigated. Further studies are warranted to confirm these findings. Support (if any) This research was supported by Tier 2 KiwiNet funding.

High-pressure NIV for acute hypercapnic respiratory failure in COPD: improved survival in a retrospective cohort study

IntroductionUpdated treatment guidelines for acute hypercapnic respiratory failure (AHRF) in chronic obstructive pulmonary disease (COPD) with non-invasive ventilation (NIV) in 2016 recommended a rapid increase in inspiratory positive airway pressure...

Effect of pressures and type of ventilation on aerosol delivery to chronic obstructive pulmonary disease patients

BackgroundContinuous Positive Airway Pressure (CPAP), BiPhasic Positive Airway Pressure (BiPAP), and high flow nasal cannula (HFNC) show some evidence to have efficacy in COVID-19 patients. Delivery during noninvasive mechanical ventilation (NIV) or HFNC gives faster and more enhanced clinical effects than when aerosols are given without assisted breath. The present work aimed to compare the effect of BiPhasic Positive Airway Pressure (BiPAP) mode at two different pressures; low BiPAP (Inspiratory Positive Airway Pressure (IPAP)/Expiratory Positive Airway Pressure (EPAP) of 10/5 cm water) and high BiPAP (IPAP/EPAP of 20/5 cm water), with HFNC system on pulmonary and systemic drug delivery of salbutamol. On the first day of the experiment, all patients received 2500 μg salbutamol using Aerogen Solo vibrating mesh nebulizer. Urine samples 30 min post-dose and cumulative urinary salbutamol during the next 24 h were collected on the next day. On the third day, the ex-vivo filter was inserted before the patient to collect the delivered dose to the patient of the 2500 μg salbutamol. Salbutamol was quantified using high-performance liquid chromatography (HPLC).ResultsLow-pressure BiPAP showed the highest amount delivered to the lung after 30 min followed by HFNC then high-pressure BiPAP. But the significant difference was only observed between low and high-pressure BiPAP modes (p = 0.012). Low-pressure BiPAP showed the highest delivered systemic delivery amount followed by HFNC then high-pressure BiPAP. Low-pressure BiPAP was significantly higher than HFNC (p = 0.017) and high-pressure BiPAP (p = 0.008). No significant difference was reported between HFNC and high-pressure BiPAP. The ex-vivo filter was the greatest in the case of low-pressure BiPAP followed by HFNC then high-pressure BiPAP. Low-pressure BiPAP was significantly higher than HFNC (p = 0.033) and high-pressure BiPAP (p = 0.008). Also, no significant difference was found between HFNC and high-pressure BiPAP.ConclusionsOur results of pulmonary, systemic, and ex-vivo drug delivery were found to be consistent. The low BiPAP delivered the highest amount followed by the HFNC then the high BiPAP with the least amount. However, no significant difference was found between HFNC and high BiPAP.

Protocol-driven early tracheal extubation in patients with flaccid neuromuscular scoliosis and pre-existing lung disease.

To review the results of a postoperative respiratory pathway for patients with muscular dystrophy (MD) and spinal muscular atrophy (SMA) undergoing spinal surgery. With IRB approval, a retrospective review was done on all patients with SMA and MD undergoing spinal surgery on a neuromuscular protocol. Baseline demographics, perioperative results, and long-term outcomes were collected. Per the protocol, patients remained intubated after surgery and were transported to the intensive care unit (ICU) for extubation. We present the results of protocol implementation and compare patients with MD to those with SMA. Twenty-four patients were treated using the protocol. Average age was 13.1years. Severe restrictive lung disease was present in 75% of patients. Nocturnal BiPAP was required in 68% of patients. Average number of instrumented levels was 17. All patients were immediately extubated upon entering the ICU. There were three respiratory complications and only was patient was re-intubated. Average ICU stay was 1.8days and average hospital length of stay was 6.7days. No differences in postoperative inspiratory or expiratory positive airway pressures were observed between the MD and SMA groups. Through a multidisciplinary neuromuscular protocol, excellent clinical outcomes were achieved in patients with neuromuscular scoliosis and restrictive lung disease, with complication rates and length of stay significantly lower than previously published data. IV.

Clinical Profile and Outcome of Children Requiring Noninvasive Ventilation (NIV).

To determine the clinical profile and outcome of children requiring noninvasive ventilation (NIV) in a PICU. This prospective observational study was conducted in the PICU at Dayanand Medical College and Hospital, Punjab. Children (1 mo-18 y) with moderate-to-severe respiratory distress who received NIV during one-year period were included. Failure was defined as the need for endotracheal intubation. The patients received bilevel positive airway pressure (BiPAP) with inspiratory and expiratory positive airway pressure (8-18cm H2O and 4-8cm), respectively and indigenous continuous positive airway pressure (CPAP) were included. Vital signs (heart rate, respiratory rate) and gasometric parameters (pH, HCO3, pCO2, pO2) were recorded. Out of total 115 patients, 81.7% were successfully treated by NIV whereas 18.3% constituted NIV failure group. Two types of NIV were used, 65.2% were started on BiPAP and 34.8% on indigenous bubble CPAP. Most common diagnosis was tropical fever (24.3%), bronchopneumonia (20%), and sepsis with multiple organ dysfunction syndrome (MODS) (7.8%). Commonest indication of NIV was respiratory distress (70.4%) and prevention of postextubation respiratory failure (20.8%). Seven patients (6.9%) died during the study. NIV failure is higher in children with sepsis with MODS, abnormal blood gas (acidosis), and moderate-to-severe acute respiratory distress syndrome (ARDS). This study demonstrates that NIV is an effective form of respiratory support for children with acute respiratory distress/failure. Sepsis with MODS, acidosis and ARDS (moderate to severe) were predictors of NIV failure. Careful patient selection may help in judicious use of NIV in PICU.

Aerosol delivery through high flow nasal cannula compared to biphasic positive airway pressure, at two different pressure: an in-vitro study

BackgroundBoth non-invasive ventilation and high flow oxygen therapy are preferred over low flow oxygen therapy in many conditions. Nebulizers, for aerosol delivery, can be used within them without interrupting the circuit. The present study aimed to compare the efficiency of drug delivery within high flow nasal cannula (HFNC) and biphasic positive airway pressure (BiPAP) ventilation mode using two different inspiratory positive airway pressures. The aerosol delivery was examined in HFNC system at low flow, 5 L min−1, and BiPAP non-invasive ventilation under 2 different pressures [high pressure; inspiratory positive airway pressure/expiratory positive airway pressure (IPAP/EPAP) of 20/5 cm water, and low pressure; IPAP/EPAP of 10/5 cm water]. The total inhalable dose (TID) was measured by inserting an Aerogen Solo nebulizer installed with 1 mL salbutamol respiratory solution (5000 μg mL−1) within the circuit, and the salbutamol was collected on an inhalation filter placed in a filter holder connected to a breathing simulator. The breathing simulator was adjusted at a tidal volume of 500 mL, respiratory rate of 15 breaths min−1, and inhalation to exhalation (I:E) ratio of 1:1 for the adult setting. In each technique of the three (HFNC, and low, and high-pressures BiPAP), TID was determined 5 times (n = 5). For particle size characterization, cooled Anderson Cascade Impactor (ACI) was inserted instead of the inhalation filter and the breathing simulator with the same scheme. In each technique of the three, particle size characterization was determined 3 times (n = 3).ResultsThe BiPAP mode at low inspiratory pressure had the highest TID, followed by HFNC at flow 5 L min−1, then BiPAP mode at high inspiratory pressure. There was a significant difference only between low and high inspiratory pressure modes of BiPAP mode. Low-inspiratory pressure BiPAP delivered the highest mean ± SD fine particle dose (FPD). It was significantly higher than that delivered in high inspiratory pressure BiPAP, and HFNC. Also, FPD in HFNC was significantly higher than that in high inspiratory pressure BiPAP. HFNC system had the smallest mass median aerodynamic diameter (MMAD) and the highest FPF followed by low then high inspiratory pressure BiPAP.ConclusionsIncreasing the inspiratory positive airway pressure in BiPAP, from 10 to 20 cm water, decreased the total inhalable dose and FPF nearly by half. Low inspiratory pressure BiPAP delivered the highest TID and FPD. The HFNC system at low oxygen flow resulted in the least MMAD, and the highest FPF. Using HFNC delivered a TID that was non-significant from that delivered by low inspiratory pressure BiPAP.Graphical

Is bilevel PAP more effective than CPAP in treating hypercapnic obese patients with COPD and severe OSA?

Commentary on Zheng Y, Yee BJ, Wong K, Grunstein R, Piper A. A pilot randomized trial comparing CPAP versus bilevel PAP spontaneous mode in the treatment of hypoventilation disorder in patients with obesity and obstructive airway disease. J Clin Sleep Med. 20XX;XX(XX):XXX-XXX. doi:10.5664/jcsm.9506.

NON-INVASIVE VENTILATION WITH AVERAGE VOLUME-ASSURED PRESSURE SUPPORT FOR ACUTE HYPERCAPNIC RESPIRATORY FAILURE

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Average volume-assured pressure support (AVAPS) is a comparatively newer modality of non-invasive ventilation that incorporates the properties of both volume and pressure-control ventilation. Though its benefits were well documented in chronic respiratory failure, studies illustrating its usage in acute respiratory failure are still insubstantial. Herein, we aim to showcase the utility of AVAPS in the management of acute on chronic hypercapnic respiratory failure. CASE PRESENTATION: An 80-year-old female with a body mass index (BMI) of 37 kg/m2 and chronic opiate use presented to the Emergency Department (ED) following a two-day history of increasing shortness of breath and confusion. Her medical history was notable for hypersensitivity pneumonitis secondary to bird exposure, former smoker, paroxysmal atrial fibrillation, and recent acute pericarditis for which she is taking aspirin and colchicine. An arterial blood gas (ABG) showed a pH of 7.14, PaCO2 of 124 mmHg (FiO2 28%), PaO2 of 94 mmHg, and bicarbonate of 41 mmol/L. A chest x-ray showed increased bilateral interstitial infiltrates. The patient received IV methylprednisolone and was placed on Spontaneous/Timed mode Bilevel positive airway pressure (BiPAP S/T) with an Inspiratory positive airway pressure (IPAP) of 10 mmHg, Expiratory positive airway pressure (EPAP) of 5 mmHg, and a respiratory rate of 12/min. At these set pressures, her inspired tidal volumes were around 400ml. The patient continued to remain confused (GCS 12/15) and thus, she was switched to average volume-assured pressure support (AVAPS) with a target tidal volume of 500ml. With this modality, she displayed rapid improvement in her symptoms and an ABG drawn eight hours after initiation revealed a pH of 7.34, PaO2 of 66 mmHg, PaO2 of 135 mmHg (FiO2 50%), and bicarbonate of 34 mmol/L. The patient was discharged home on the 5th day after admission. DISCUSSION: AVAPS is an intelligent modality of non-invasive pressure support that gives us the option to set a maximum and a minimum IPAP, in place of one fixed IPAP setting, along with a target tidal volume. The ventilator automatically adjusts the inspiratory pressure within the set range to ensure the delivery of pre-set tidal volume. Patient-ventilator dyssynchronization is prevented and previous studies have reported better patient comfort and satisfaction with AVAPS, thereby, improving patient compliance to the treatment. AVAPS was shown to be superior to BiPAP S/T and associated with a rapid improvement of ABG values and GCS score in patients with acute hypercapnic respiratory failure complicated with hypercapnic encephalopathy (GCS <10/15). CONCLUSIONS: Our case highlights the valuable utility of AVAPS and how, in certain clinical situations, it may be a preferred first-line modality over standard BiPAP S/T for the treatment of acute hypercapnic respiratory failure. REFERENCE #1: Yarrarapu SNS, Saunders H, Sanghavi D. Average Volume-Assured Pressure Support. 2021 Jan 5. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 32809435. DISCLOSURES: No relevant relationships by Pramod Guru, source=Web Response No relevant relationships by Devang Sanghavi, source=Web Response No relevant relationships by Hollie Saunders, source=Web Response No relevant relationships by Siva Naga Yarrarapu, source=Web Response

Sleep increases leaks and asynchronies during home noninvasive ventilation: a polysomnographic study.

In patients treated with noninvasive ventilation, sleep-related breathing changes can modify patient-ventilator interactions, which could reduce its effectiveness. The aim of this prospective observational study was to determine the impact of sleep/wake state on leaks, upper airway obstructive events, and asynchronies in patients treated by long-term noninvasive ventilation. Stable patients adapted to noninvasive ventilation were considered for nocturnal polysomnography. Unintentional leaks, upper airway obstructive events, and asynchronies were compared between sleep and awake periods. Twenty-eight patients were enrolled. Underlying diagnoses were neuromuscular disease (n = 11), chest wall disease (n = 8), and obesity-hypoventilation (n = 9). Leaks were more frequent in sleep than in awake periods, with a median of 10% (interquartile range [IQR], 0%-75%) vs 1% (IQR, 0%-9%) of time (P < .001), respectively. During sleep, asynchronies with and without associated leak affected 27% of breaths (IQR, 16%-39%) compared with non-leak-related asynchronies that were recorded in 8% (IQR, 3%-25%) of breaths (P < .001). Asynchronies affecting more than 10% of total breaths were more frequent in sleep (25 patients, 89%) than in awake time (8 patients, 29%; P = .25). Eleven patients (39%) presented with 5 or more upper airway obstructive events without reduction in ventilatory drive per hour of sleep. In patients adapted to home noninvasive ventilation, leaks, asynchronies, and upper airway obstructive events are frequent during the night and are concentrated in sleep periods. Asynchronies are often associated with leaks. These findings may have clinical implications considering that in patients with low sleep efficiency respiratory events could be underestimated if sleep is not evaluated. Martí S, Ferré A, Sampol G, etal. Sleep increases leaks and asynchronies during home noninvasive ventilation: a polysomnographic study. J Clin Sleep Med. 2022;18(1):225-233.

Current Practices in Home Mechanical Ventilation for Chronic Obstructive Pulmonary Disease: A Real-Life Cross-Sectional Multicentric Study.

PurposeHome mechanical ventilation (HMV) use in chronic obstructive pulmonary disease (COPD) is becoming increasingly widespread. The aim of this study was to provide an accurate description of the current practices and clinical characteristics of COPD patients on HMV in Portugal.MethodsThe study was designed as a cross-sectional, multicenter real-life study of COPD patients established on HMV for at least 30 days. Data related to clinical characteristics, adaptation and ventilatory settings were collected.ResultsThe study included 569 COPD patients on HMV from 15 centers. The majority were male, with a median age of 72 years and a high prevalence of obesity (43.2%) and sleep apnea (45.8%). A high treatment compliance was observed (median 8h/day), 48.7% with inspiratory positive airway pressure ≥20 cmH2O and oronasal masks were the preferred interface (91.7%). There was an equal distribution of patients starting HMV during chronic stable condition and following an exacerbation. Patients in stable condition were initiated in the outpatient setting in 92.3%. Despite the differences in criteria and setting of adaptation and a slightly lower BMI in patients starting HMV following an exacerbation, we found no significant differences regarding age, gender, ventilation pressures, time on HMV, usage, severity of airflow obstruction or current arterial blood gas analysis (ABGs) in relation to patients adapted in stable condition.ConclusionPatients were highly compliant with the therapy. In agreement with most recent studies and recommendations, there seems to be a move towards higher ventilation pressures, increased use of oronasal masks and an intent to obtain normocapnia. This study shows that chronic hypercapnic and post exacerbation patients do not differ significantly regarding patient characteristics, physiological parameters or ventilatory settings with one exception: chronic hypercapnic patients are more often obese and, subsequently, more frequently present OSA.

Characterizing respiratory parameters, settings, and adherence in real-world patients using adaptive servo ventilation therapy: big data analysis.

There is minimal guidance around how to optimize inspiratory positive airway pressure (IPAP) levels during use of adaptive servo ventilation (ASV) in clinical practice. This real-world data analysis investigated the effects of IPAP and minimum pressure support settings on respiratory parameters and adherence in ASV-treated patients. A United States-based telemonitoring database was queried for patients starting ASV between August 1, 2014 and November 30, 2019. Patients meeting the following criteria were included: United States-based patients aged ≥ 18 years; AirCurve 10 device (ResMed); and ≥ 1 session with usage of ≥ 1 hour in the first 90 days. Key outcomes were mask leak and residual apnea-hypopnea index at different IPAP settings, adherence and therapy termination rates, and respiratory parameters at different minimum pressure support settings. There were 63,996 patients included. Higher IPAP was associated with increased residual apnea-hypopnea index and mask leak but did not impact device usage per session (average > 6 h/day at all IPAP settings; 6.7 h/day at 95th percentile IPAP 25 cm H2O). There were no clinically relevant differences in respiratory rate, minute ventilation, leak, and residual apnea-hypopnea index across all possible minimum pressure support settings. Patients with a higher 95th percentile IPAP or with minimum pressure support of 3 cm H2O were most likely to remain on ASV therapy at 1 year. Our findings showed robust levels of longer-term adherence to ASV therapy in a large group of real-world patients. There were no clinically important differences in respiratory parameters across a range of pressure and pressure support settings. Future work should focus on the different phenotypes of patients using ASV therapy. Malhotra A, Benjafield AV, Cistulli PA, etal. Characterizing respiratory parameters, settings, and adherence in real-world patients using adaptive servo ventilation therapy: big data analysis. J Clin Sleep Med. 2021;17(12):2355-2362.

Treatment of critically ill patients with acute hypercarbic respiratory failure by average volume‐assured pressure support mode

Average volume-assured pressure support (AVAPS), a dual mode, delivers a set tidal volume (TV) per kg by adjusting the pressure between upper and lower inspiratory positive airway pressures (IPAP). Thus, ventilation is presumed to be happened effectively by sending a guaranteed TV. This study was aimed to evaluate the effectiveness of AVAPS mode in critically ill patients with acute hypercarbic respiratory failure (HRF) and compare the results with bilevel positive airway pressure-spontaneous/timed (BPAP-S/T) mode. Sixty patients were assigned to BPAP-S/T (n=29) and AVAPS modes (n=31). Maximum IPAP was started at 20 cmH2 O and minimum IPAP was set at 5 cmH2 O higher than expiratory positive airway pressure (EPAP) in AVAPS mode. IPAP was started at 15 cmH2 O in BPAP-S/T mode. IPAP levels were titrated up to 30 cmH2 O during noninvasive mechanic ventilation (NIMV) with a targeted TV of 6-8 mL/kg. Patients were followed for 5 days. No differences were found in pH, paCO2 , HCO3 , TV and EPAP between the two groups when compared separately by days. Maximum IPAP levels were significantly high in AVAPS mode in all times (P<0.001). The length of stay (LOS) in intensive care unit (ICU) (P=0.994) and hospital (P=0.509), hours of NIMV use per day (P=0.101) and NIMV success rate (P=0.931) were identical between the two groups. ICU (P=0.931), hospital (P=0.800), 6-month (P=0.919) and 1-year (P=0.645) mortality rates were also not different between the both groups. AVAPS mode had similar efficiency with BPAP-S/T mode regarding the NIMV treatment success in critically ill patients with acute HRF.

Determinants of usage and nonadherence to noninvasive ventilation in children and adults with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to chronic respiratory insufficiency and failure. Use of home noninvasive ventilation (NIV) has been linked to improved outcomes including reduced mortality. Despite the importance of NIV, factors promoting optimal NIV usage and determinants of nonadherence have not been rigorously examined. Moreover, given that respiratory issues in DMD span between childhood and adulthood, examination across a broad age group is needed. The objectives of this study were to (1) evaluate NIV usage across a broad spectrum of patients with DMD, including both children and adults, and (2) identify biological and socioeconomic determinants of NIV usage and NIV nonadherence. We performed a retrospective review of all patients with DMD from February 2016 to February 2020 who underwent evaluation at associated pediatric and adult neuromuscular disease clinics. NIV use was determined objectively from device downloads. A priori, we defined nonadherence as < 4 hours use per night, quantified as the percentage of nights below this threshold across a 30-day period within 6 months of a clinic visit. We also assessed the average hours of NIV usage over this time period. Predictors examined included demographics, social determinants, and pulmonary function. 33 patients with DMD were identified, 29 (87%) of whom were using NIV (13 age < 21 years). Mean age was 22.9 ± 6.6 years (range 13-39 years), body mass index was 23.4 ± 10.4 kg/m2, and seated forced vital capacity was 23% ± 18% predicted. Mean nightly NIV usage was 7.4 ± 3.8 hours and mean percentage of nonadherent nights was 13% ± 30%. In univariable analysis, age did not predict use. Those with lower forced vital capacity had higher NIV usage hours (P = .01) and a trend toward less nonadherence (P = .06). Higher estimated household income demonstrated a trend toward increased usage hours and less nonadherence (both P = .08). Multivariable analysis found increased usage hours were predicted best by higher income, higher inspiratory positive airway pressure, and higher bicarbonate. Nonadherence was higher in those with lower income or higher forced vital capacity. In this cohort of adult and pediatric patients with DMD, most individuals were using NIV. While usage hours were higher with lower lung function, substantial variability remains unexplained by examined factors. Nonadherence was observed in some individuals, including those with advanced disease. Further investigations should focus on evaluating patient-oriented outcomes to define optimal NIV usage across the spectrum of disease and determine strategies to counteract issues with nonadherence. Hurvitz MS, Bhattacharjee R, Lesser DJ, Skalsky AJ, Orr JE. Determinants of usage and nonadherence to noninvasive ventilation in children and adults with Duchenne muscular dystrophy. J Clin Sleep Med. 2021;17(10):1973-1980.

The Effect of Different Interfaces on the Aerosol Delivery with Vibrating Mesh Nebulizer During Noninvasive Positive Pressure Ventilation

Background: The effect of different interfaces on the aerosol delivery with vibrating mesh nebulizer during noninvasive positive pressure ventilation (NIV) is not clear. Materials and Methods: Noninvasive ventilator and four interfaces were connected to IngMar ASL 5000 lung simulator. Meanwhile, the vibrating mesh nebulizer was connected to a ventilator circuit to simulate the nebulization during noninvasive ventilation. The nebulizer position was placed at proximal position (near the mask) and distal position (15 cm away from the mask); the inspiratory positive airway pressure (IPAP) and the expiratory positive airway pressure (EPAP) were set to 16/4, 16/8, 20/4, and 20/8 cmH2O, respectively. The aerosol was collected through a disposable filter placed between the simulated lung and the mask, after which the aerosol delivery was calculated. Meanwhile, we recorded the inspiratory tidal volume and the mean inspiratory flow. Results: The aerosol delivery varied between 1.7% ± 0.0% and 21.1% ± 1.1%. Only when EPAP was set to 4 cmH2O, the statistical difference in aerosol delivery was observed between the two types of interface, and between different leak port locations (p < 0.01; p = 0.04, respectively). When IPAP/EPAP was set to 16/4 and 20/4 cmH2O, respectively, at different nebulizer positions, there was a statistical difference between the interface with the same type but different leak port locations and between the interface with same leak port location but different inner volumes (all p < 0.01). Also, there was a correlation between the aerosol delivery and interface volume (p < 0.01, R2 = 0.55; p < 0.01, R2 = 0.51, respectively), and between aerosol delivery and the intentional leak of interfaces (p < 0.01, R2 = 0.59; p < 0.01, R2 = 0.48, respectively). When EPAP was set to 4 and 8 cmH2O, respectively, the aerosol delivery of nebulizer distal position was significantly higher than that of proximal position (12.2% ± 5.0% vs. 9.1% ± 4.1%, p < 0.05; 2.5% ± 0. 5% vs. 2.1% ± 0.3%, p < 0.01, respectively). Conclusion: Interfaces have a significant effect on aerosol delivery during NIV. The interfaces with different inner volumes, intentional leak, and leak port location may all have an effect on aerosol delivery. The addition of a 15 cm tube between the nebulizer and the mask significantly increases the aerosol delivery.