Levels Of Positive Airway Pressure Research Articles

High-flow nasal cannula therapy for infants with bronchiolitis.

Bronchiolitis is a common lower respiratory tract illness, usually of viral aetiology, affecting infants younger than 24 months of age and is the most common cause of hospitalisation of infants. It causes airway inflammation, mucus production and mucous plugging, resulting in airway obstruction. Effective pharmacotherapy is lacking and bronchiolitis is a major cause of morbidity and mortality. Conventional treatment consists of supportive therapy in the form of fluids, supplemental oxygen, and respiratory support. Traditionally, oxygen delivery is as a dry gas at 100% concentration via low-flow nasal prongs. However, the use of heated, humidified, high-flow nasal cannula (HFNC) therapy enables delivery of higher inspired gas flows of an air/oxygen blend, at 2 to 3 L/kg per minute up to 60 L/min in children. It can provide some level of continuous positive airway pressure (CPAP) to improve ventilation in a minimally invasive manner. This may reduce the need for invasive respiratory support, thus potentially lowering costs, with clinical advantages and fewer adverse effects. To assess the effects of HFNC therapy compared with conventional respiratory support in the treatment of infants with bronchiolitis. We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, and Web of Science (from June 2013 to December 2022). In addition, we consulted ongoing trial registers and experts in the field to identify ongoing studies, checked reference lists of relevant articles, and searched for conference abstracts. Date restrictions were imposed such that we only searched for studies published after the original version of this review. We included randomised controlled trials (RCTs) or quasi-RCTs that assessed the effects of HFNC (delivering oxygen or oxygen/room air blend at flow rates greater than 4 L/minute) compared to conventional treatment in infants (< 24 months) with a clinical diagnosis of bronchiolitis. Two review authors independently used a standard template to assess trials for inclusion and extract data on study characteristics, risk of bias elements, and outcomes. We contacted trial authors to request missing data. Outcome measures included the need for invasive respiratory support and time until discharge, clinical severity measures, oxygen saturation, duration of oxygen therapy, and adverse events. In this update we included 15 new RCTs (2794 participants), bringing the total number of RCTs to 16 (2813 participants). Of the 16 studies, 11 compared high-flow to low-flow, and five compared high-flow to CPAP. These studies included infants less than 24 months of age as stated in our selection criteria. There were no significant differences in sex. We found that when comparing high-flow to low-flow oxygen therapy for infants with bronchiolitis there may be a reduction in the total length of hospital stay (mean difference (MD) -0.65 days, 95% confidence interval (CI) -1.23 to -0.06; P < 0.00001, I2 = 89%; 7 studies, 1951 participants; low-certainty evidence). There may also be a reduction in the duration of oxygen therapy (MD -0.59 days, 95% CI -1 to -0.18; P < 0.00001, I2 = 86%; 7 studies, 2132 participants; low-certainty evidence). We also found that there was probably an improvement in respiratory rate at one and 24 hours, and heart rate at one, four to six, and 24 hours in those receiving high-flow oxygen therapy when compared to pre-intervention baselines. There was also probably a reduced risk of treatment escalation in those receiving high-flow when compared to low-flow oxygen therapy (risk ratio (RR) 0.55, 95% CI 0.39 to 0.79; P = 0.001, I2 = 43%; 8 studies, 2215 participants; moderate-certainty evidence). We found no difference in the incidence of adverse events (RR 1.2, 95% CI 0.38 to 3.74; P = 0.76, I2 = 26%; 4 studies, 1789 participants; low-certainty evidence) between the two groups. The lack of comparable outcomes in studies comparing high-flow and CPAP, as well as the small numbers of participants, limited our ability to perform meta-analysis on this group. High-flow nasal cannula therapy may have some benefits over low-flow oxygen for infants with bronchiolitis in terms of a greater improvement in respiratory and heart rates, as well as a modest reduction in the length of hospital stay and duration of oxygen therapy, with a reduced incidence of treatment escalation. There does not appear to be a difference in the number of adverse events. Further studies comparing high-flow nasal cannula therapy and CPAP are required to demonstrate the efficacy of one modality over the other. A standardised clinical definition of bronchiolitis, as well as the use of a validated clinical severity score, would allow for greater and more accurate comparison between studies.

Influence of various positive airway pressure levels on catheterization of the right internal jugular vein

Background: Central venous catheterization is a commonly used method of administering drugs and measuring central venous pressure during major surgery. Chronic obstructive pulmonary disease, acute respiratory distress syndrome, and obstructive sleep apnea are among the respiratory disorders that can be treated with positive airway pressure (PAP). While PAP therapy benefits patients with respiratory disorders, its impact on central venous catheterization must be more adequately studied, particularly in the right internal jugular vein (RTIJV). Aims and Objectives: The study aimed to predict the most applicable PAP for RTIJV catheterization and to evaluate the complications with different airway pressures. Materials and Methods: This study was conducted using a comparative prospective randomized control trial study design in a tertiary care hospital. One hundred participants were selected from subjects who came for gastrointestinal tract surgery and urological surgery, and they were randomized through a computer-generated random number table. Results: Participants were divided into four different groups (A, B, C, and D), and they were subjected to four pressures 0 cmH2O, 10 cmH2O, 15 cmH2O, and 20 cmH2O, respectively. The cross-sectional area of RTIJV is significantly increased in Groups C and D compared to Groups A and B. The number of completed catheterizations was higher in Groups C and D. The number of first-pass punctures was also higher in Groups C and D. Depth of needle insertion is significantly reduced with increased pressure. Conclusion: Moderate-to-high PAPs, specifically around 15 cmH2O to 20 cmH2O, boost catheterization success. This is achieved through improved vein dilation, enhanced accuracy, and decreased needle insertion depth.

The Beginning of the AI-Enabled Preventative PAP Therapy Era: A First-in-Human Proof of Concept Interventional Study.

Positive Airway Pressure (PAP) therapy is the most common and efficacious treatment for Obstructive Sleep Apnea (OSA). However, it suffers from poor patient adherence due to discomfort and may not fully alleviate all adverse consequences of OSA. Identifying abnormal respiratory events before they have occurred may allow for improved management of PAP levels, leading to improved adherence and better patient outcomes. Our previous work has resulted in the successful development of a Machine-Learning (ML) algorithm for the prediction of future apneic events using existing airflow and air pressure sensors available internally to PAP devices. Although researchers have studied the use of ML for the prediction of apneas, research to date has focused primarily on using external polysomnography sensors that add to patient discomfort and has not investigated the use of internal-to-PAP sensors such as air pressure and airflow to predict and prevent respiratory events. We hypothesized that by using our predictive software, OSA events could be proactively prevented while maintaining patients' sleep quality. An intervention protocol was developed and applied to all patients to prevent OSA events. Although the protocol's cool-down period limited the number of prevention attempts, analysis of 11 participants revealed that our system improved many sleep parameters, which included a statistically significant 31.6% reduction in Apnea-Hypopnea Index, while maintaining sleep quality. Most importantly, our findings indicate the feasibility of unobtrusive identification and unique prevention of each respiratory event as well as paving the path to future truly personalized PAP therapy by further training of ML models on individual patients.

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.

Focused transoesophageal TOE (fTOE): A new accreditation pathway.

The concept of a focused ultrasound study to identify sources of haemodynamic instability has revolutionized patient care. Point-of-care ultrasound (POCUS) using transthoracic scanning protocols, such as FUSIC Heart, has empowered non-cardiologists to rapidly identify and treat the major causes of haemodynamic instability. There are, however, circumstances when a transoesphageal, rather than transthoracic approach, may be preferrable. Due to the close anatomical proximity between the oesophagus, stomach and heart, a transoesphageal echocardiogram (TOE) can potentially overcome many of the limitations encountered in patients with poor transthoracic ultrasound windows. These are typically patients with severe obesity, chest wall injuries, inability to lie in the left lateral decubitus position and those receiving high levels of positive airway pressure. In 2022, to provide all acute care practitioners with the opportunity to acquire competency in focused TOE, the Intensive Care Society (ICS) and Association of Anaesthetists (AA) launched a new accreditation pathway, known as Focused Transoesophageal Echo (fTOE). The aim of fTOE is to provide the practitioner with the necessary information to identify the aetiology of haemodynamic instability. Focused TOE can be taught in a shorter period of time than comprehensive and teaching programmes are achievable with support from cardiothoracic anaesthetists, intensivists and cardiologists. Registration for fTOE accreditation requires registration via the ICS website. Learning material include theoretical modules, clinical cases and multiple-choice questions. Fifty fTOE examinations are required for the logbook, and these must cover a range of pathology, including ventricular dysfunction, pericardial effusion, tamponade, pleural effusion and low preload. The final practical assessment may be undertaken when the supervisors deem the candidate's knowledge and skills consistent with that required for independent practice. After the practitioner has been accredited in fTOE, they must maintain knowledge and competence through relevant continuing medical education. Accreditation in fTOE represents a joint venture between the ICS and AA and is endorsed by Association of Cardiothoracic Anaesthesia and Critical care (ACTACC). The process is led by TOE experts, and represents a valuable expansion in the armamentarium of acute care practitioners to assess haemodynamically unstable patients.

0444 Racial Differences in Positive Airway Pressure Requirements Amongst Obstructive Sleep Apnea Patients (The RACE-PAP Study)

Abstract Introduction Prior studies of patients with obstructive sleep apnea (OSA) show racial differences in clinical presentation. When compared with White patients, Black patients present with more severe OSA and greater sleepiness. Racial differences in upper airway collapsibility could explain these differences. Here, we investigated whether mean positive airway pressure (PAP) levels, a clinically accessible measure of upper airway collapsibility, differed by race in a cohort of patients adherent to PAP. Methods We conducted a retrospective analysis of White and Black adults with OSA who were prescribed auto-adjusting PAP (aPAP) therapy at a single academic center between January 2018 and January 2020. The analysis included adherent patients (usage on &amp;gt;70% of nights for ≥4 hours per night) with well-controlled OSA (defined as ≥50% reduction in apnea-hypopnea index [AHI] on aPAP and residual AHI&amp;lt; 10). Mean PAP level was compared between White and Black patients using linear regression controlled for age, gender, body mass index (BMI), AHI, O2 nadir, and mask type (full face, nasal, or unknown). Results Overall, 148 Black (56% women) and 230 White (36% women) patients were included. On average, Black patients were younger (50.7±14.6 vs. 53.8±12.7 years; p=0.037) with higher BMI (40.4±9.5 vs. 34.9±7.6 kg/m2; p&amp;lt; 0.0001). Black patients had less severe OSA on average, but this difference was not statistically significant (AHI of 33.9±25.5 vs 38.6±24.9 events/hour; p=0.077). After adjusting for covariates, Black patients had a 0.62 cm H2O (95% CI: 0.21 to 1.03) higher mean PAP level than White patients (p=0.003). There was a larger racial difference in mean PAP level among men (0.76 [0.16, 1.35] cm H2O; p=0.013) compared to a non-significant difference among women (0.34 [-0.23, 0.91] cm H2O; p=0.242). While statistically significant, differences were &amp;lt; 1 cm H2O and, thus, not clinically meaningful. Conclusion Black patients with OSA had a statistically significant but clinically insignificant difference in mean PAP level when compared with White patients. There was evidence of stronger differences in men than women. Further studies are needed to explore other potential mechanisms, including craniofacial anatomy, which may underlie racial differences in OSA presentation and outcomes. Support (if any) National Institutes of Health R01 1R01HL144859 (PIs: Schwartz, Dedhia)

MEGF10 gene mutations causing a recessive congenital multiminicore myopathy (P9-9.010)

<h3>Objective:</h3> Congenital myopathies are classified into five main types: core myopathies, nemaline myopathies, centronuclear myopathies, congenital fiber-type disproportion, and myosin storage myopathies. The most common forms are core myopathies. Despite their phenotypic diversity, patients demonstrate common symptoms including hypotonia, muscle weakness, dysmorphic features, and respiratory problems. There are several mutations in <i>MEGF10</i> that have been reported to cause autosomal recessive congenital myopathy, areflexia, respiratory distress, muscle weakness, dysphagia with early or late-onset syndrome, minicore myopathy and limb girdle muscular dystrophy. Affected individuals frequently become ventilator dependent or die secondary to respiratory failure. <h3>Background:</h3> A 5-year-old girl from a consanguineous couple was referred to our service due to weakness and hypotonia. After birth, she developed respiratory failure. Severe motor delay was already evident in the first months of life: at 6 months she had no cervical control and at 12 months she could not sit without support. At age 3 she developed respiratory problems with apnea and hypercapnia, requiring ventilation with two levels of positive airway pressure. She was indicated for gastrostomy at age 4 after aspiration pneumonia. On her evaluation, she had axial and proximal muscle weakness, facial weakness, scoliosis, and nasal speech. Despite presenting hypotonia and gait difficulties, she was able to walk independently and had no cognitive changes. A muscle biopsy was performed which suggested multiminicore myopathy. Genetic investigation resulted in a homozygous mutation of the <i>MEGF10</i> gene. <h3>Design/Methods:</h3> NA <h3>Results:</h3> NA <h3>Conclusions:</h3> <i>MEGF10</i> mutations should be considered in the differential diagnosis of individuals with respiratory insufficiency and myopathy, particularly when accompanied by facial weakness, scoliosis or dysphagia. The phenotypic similarities with other congenital neuromuscular disorders may cause difficulties in reaching a definite diagnosis. Treatment with a multidisciplinary team is important and family counseling is essential since consanguineous unions play a role in recessive genetic mutations manifestations. <b>Disclosure:</b> Miss Faria has nothing to disclose. Dr. Barbosa has nothing to disclose. Mrs. Ribeiro Torres has nothing to disclose. Mr. E Souza Filho has received research support from Universidade Federal de Minas Gerais. Mrs. Thiersch has nothing to disclose. Mrs. Oliveira has nothing to disclose.

Real-world data evaluation of PAP responsiveness in pediatric obstructive sleep apnea.

The use of positive airway pressure (PAP) in children is a complex process determined by multiple factors. There are limited data on the response of the pediatric population to PAP therapy at home. The goal of the study was to examine real-world responses using PAP home monitoring in children with obstructive sleep apnea. The study included PAP therapy data for 195 children aged between 1 month and 18 years with obstructive sleep apnea and polysomnogram baseline study. We collected demographics, clinical variables, and polysomnogram parameters in all study participants. The individual response to PAP therapy was calculated comparing the apnea-hypopnea index (AHI) in the initial polysomnogram with the mean AHI provided by the download of PAP devices. Multivariate models (logistic regression) were used to examine the predictors of positive PAP response defined as a reduction in AHI ≥ 75%. We found excellent responses to PAP therapy in children (median 85% AHI reduction). However, there was substantial heterogeneity in AHI reductions while on PAP therapy. The best PAP responses were linked to more severe obstructive sleep apnea and higher PAP levels. We also identified that the response to PAP was higher in obese children and lower in males. The best predictive model for individual PAP response was biological sex, obesity, and obstructive AHI ≥ 20 events/h (area under the receiver operating characteristic curve of 0.791). Real-world data show that PAP is overall an effective therapy in children but the response is heterogeneous. Obstructive sleep apnea parameters and individual factors can be used to predict individual AHI reductions while on PAP and optimize PAP responses at home. Aguilar H, Kahanowitch R, Weiss M, etal. Real-world data evaluation of PAP responsiveness in pediatric obstructive sleep apnea. J Clin Sleep Med. 2023;19(7):1313-1319.

Efficacy of high-flow nasal oxygen during drug-induced sleep endoscopy in patients with obstructive sleep apnea.

High-flow nasal oxygenation (HFNO) can provide a low level of continuous positive airway pressure and alveolar recruitment. We aimed to compare the efficacy of pre-oxygenation with HFNO and low-flow nasal oxygenation (LFNO) during drug-induced sleep endoscopy (DISE). In the LFNO group, preoxygenation was performed for 10 min at 3 L·min-1. In the HFNO group, preoxygenation was performed for 10 min at 30 L·min-1 at a fraction of inspired oxygen of 100% using the Optiflow device. From the start of sedative administration to the end of DISE, vital signs were monitored continuously. The primary outcome was the lowest oxygen saturation (SpO2) during DISE. Of 24 patients enrolled, 12 were randomly assigned to the LFNO and 12 to the HFNO groups. Theprevalence of hypoxia events was 75% in the LFNO group and 58% in the HFNO group. The difference in lowest oxygen saturation between the two groups was not significant between the two groups (P=0.665). The lowest SpO2 during all procedures was comparable between the two groups (86.8 ± 6.5% in the LFNO group and 87.2 ± 8.0% in the HFNO group; P=0.912). The findings suggest thatHFNO may not be superior to LFNO as a preoxygenation tool to prevent hypoxia during DISE.

Relationship between level CPAP titration, anthropometric variables, and drug-induced sleep endoscopy DISE.

Subjects with palatal obstruction alone vs. multilevel obstruction on DISE had better outcomes after palate surgery. We asked ourselves if the therapeutic level positive airway pressure (PAP) titration could predict the level of airway obstruction and its complexity. The aim of this study was to identify possible relationships between therapeutic level of positive airway pressure initial titration and levels of collapse in drug-induced sleep endoscopy (DISE). A secondary objective wasto establish the relationship the other variables and DISE. We analyzed retrospective clinical histories between March 2020 to March 2022 of 37 patients with polysomnography or cardiorespiratory polygraphy studies and PAP initial titration who were taken to drug-induced sleep endoscopy. Sleep study data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with PAP initial titration levels. Most of the patients with complex collapse had concentric velum collapse (p < 0.006). A significant association was found between the apnea-hypopnea index (AHI) and oropharyngeal collapse; (p < 0.0030) and finally we demonstrated relationship between neck circumference and gender with epiglottis collapse (p < 0.046), (p < 0.037), respectively. Our findings show a strong relationship between that complex collapses and concentric velum collapse; patients with greater oropharyngeal collapse have a higher mean AHI. Patients without epiglottic collapse have a higher mean neck circumference. An association between mean pressure initial titration and complex collapse could not be established.

Ultrasound Assessment of Gastric Volume in Parturients After High-Flow Nasal Oxygen Therapy.

High-flow nasal oxygen (HFNO) therapy is widely used in critical care obstetrics to improve oxygenation. Much of the benefit of HFNO is linked to the creation of modest levels of positive airway pressure. Pregnant women are generally considered to be at high risk of regurgitation and aspiration. It is unknown whether HFNO may cause gas insufflation into the stomach and further increase this risk. Therefore, this study aimed to systematically evaluate the possible safety effects of HFNO on gastric volume in healthy fasted parturients. Sixty fasted parturients scheduled for elective cesarean delivery were enrolled in an observer-blinded, prospective, interventional study. We used ultrasonography to assess changes of antral cross-sectional area (CSA) and gastric volume before and after a 20-minute treatment with HFNO at a rate of 50 L·min -1 . The primary outcome was the change in gastric volume from before to after HFNO therapy, and the secondary outcome was the distribution of antral grades. In semirecumbent right lateral position, the antral CSA at baseline and after treatment with HFNO was 3.81 (3.01-4.72) cm 2 and 3.79 (3.03-4.54) cm 2 , respectively. The estimated fluid volume at baseline and after treatment with HFNO was 38.51 (33.39-54.62) mL and 39.71 (32.00-52.82) mL, respectively. All participants had either a grade 0 or grade 1 antrum, and most of them had a grade 0 antrum. There was no significant difference in gastric volume and distribution of antral grades before and after HFNO therapy. Gastric air distension was not shown in any of the parturients either at baseline or after treatment with HFNO. Treatment with HFNO for 20 minutes at flow rates up to 50 L·min -1 did not increase gastric volume in term pregnant women breathing spontaneously when evaluated by gastric ultrasonography.

Factors determining the therapeutic level of positive airway pressure in patients with obstructive sleep apnea syndrome.

In daily practice, we encounter with obstructive sleep apnoea syndrome (OSAS) patients who require different levels of positive airway pressure (PAP) despite having a similar apnoea-hypopnea index (AHI). We aimed to determine the parameters contributing to the determination of the therapeutic level of PAP. Data on 548 patients who underwent polysomnography and PAP titration were analysed retrospectively. Patients were divided into groups according to OSAS severity (mild, moderate, and severe) and the mean pressure in each group was determined, after which patients were further divided into those who required a PAP below the mean and those who required a PAP above the mean. The mean optimal PAP level in the mild, moderate, and severe OSAS groups was 7.4 ± 2.3, 8.6 ± 2.4, and 9.8 ± 2.9 cm H2O, respectively. In the moderate and severe OSAS group, the subgroup that needed high pressure had a higher supine AHI, a longer apnoea time, and a longer SaO2 <90% time as compared with the subgroup that needed low pressure. A longer apnoea duration and a higher supine AHI are associated with a higher PAP level in patients with moderate and severe OSAS.

Predictors of optimum continous positive airway pressure level in obstructive sleep apnoea patients

Background: Obstructive sleep apnoea (OSA) is a breathing disorder during sleep which leads to life-threatening events. The recommended treatment for moderate to severe OSA is continuous positive pressure therapy (CPAP). Aim: To predict the optimal CPAP level in OSA. Methodology: This was a cross sectional observational study, carried out in pulmonary medicine department at a tertiary referral centre in South India. Twenty patients were recruited in the study over a period of 6 months. All patients in study group underwent CPAP titration with optimal or good titration over a full night polysomnography. Results: We correlated the optimal CPAP level with demographic, anthropometric and polysomnographic variables, which showed a trend of association between body mass index (BMI), neck circumference, apnoea hypopnoea index (AHI), oxygen desaturation index (ODI) and severity of OSA with optimal CPAP level Conclusion: No statistically significant association was observed between demographic, clinical, anthropometric and polysomnographic variables with optimal CPAP level.

The Effect of Pharyngeal Surgery on Positive Airway Pressure Therapy in Obstructive Sleep Apnea: A Meta-Analysis.

There is controversy about the effect of pharyngeal surgery for obstructive sleep apnea (OSA) on positive airway pressure (PAP) adherence, and the related results of meta-analysis have not yet been available. Therefore, the purpose of this meta-analysis was to assess the effect of pharyngeal OSA surgery on PAP therapy parameters such as optimal pressure levels and usage time. We selected studies investigating optimal PAP levels or usage time before and after pharyngeal OSA surgery, regardless of the study design. Pharyngeal OSA surgery included uvulopalatopharyngoplasty and its variants, tonsillectomy, Pillar implants, radiofrequency ablation, tongue base surgery and its variants, and genioglossus advancement. Studies in which isolated nasal surgery was performed were excluded. The random-effects model was used due to significant heterogeneity among the studies. Nine studies were included in the meta-analysis of optimal PAP levels, and five studies in the meta-analysis of PAP usage time. After pharyngeal OSA surgery, the summed optimal PAP level was significantly decreased (standardized mean difference (SMD), -1.113; 95% confidence interval (CI), -1.667 to -0.559)), and the summed usage time of PAP was significantly increased (SMD, 0.794; 95% CI, 0.259 to 1.329). This study illustrated that pharyngeal OSA surgery lowered optimal PAP levels and enhanced PAP usage time. The results of the meta-analysis contribute to our understanding of the role of pharyngeal OSA surgery in patients with PAP intolerance.

The Need for Titration With Polysomnography of Noninvasive Positive Pressure Ventilation in a Patient With Hypoventilation Syndrome With Kyphoscoliosis

Attended noninvasive positive airway pressure (PAP) with polysomnography (PSG) is recommended for determining the level of ventilatory support and bilevel PAP required for patients with chronic alveolar hypoventilation syndromes. We present a case of a 24-year-old male with kyphoscoliosis who presented with dyspnea. The patient was diagnosed with chronic alveolar hypoventilation and had bilevel PAP titrated by referring to tidal volume and arterial gas analysis during the day. After further titration with PSG there was stable ventilation during non-rapid eye movement sleep but unstable on entering rapid eye movement sleep.

0804 Enhanced Drug-Induced Sleep Endoscopy: Distinguishing Central from Obstructive Apneas

Abstract Introduction Drug-induced sleep endoscopy (DISE) is a useful tool for assessing upper airway collapse in patients with obstructive sleep apnea (OSA) and frequently influences surgical plans. The standard DISE setup of an endoscopic tower with flexible bronchoscope is adequate for visualizing collapse configurations, but endoscopic findings do not always correlate with actual respiratory physiology. We describe our enhanced clinical DISE setup incorporating nasal flow and respiratory effort measurements, which facilitates differentiation between central and obstructive events. Central sleep apnea was detected in two patients who were originally diagnosed with OSA and underwent DISE during hypoglossal nerve stimulation candidacy workup. Report of Cases: Case 1 is a 58-year-old male with cardiomyopathy, atrial fibrillation and congestive heart failure who was diagnosed with moderate OSA on a home sleep apnea test. He was PAP intolerant due to claustrophobia. DISE during baseline breathing revealed complete anteroposterior collapse at the palate, tongue base and epiglottis. However, central apneas with Cheyne-Stokes breathing were noticed when positive airway pressure (PAP) was applied. A subsequent polysomnogram revealed severe sleep apnea which was primarily central in nature with Cheyne-Stokes breathing and OSA. He declined retrying PAP and opted for phrenic nerve stimulation. Case 2 is a 48-year-old male with a history of aortic valve repair, hypothyroidism, atrial fibrillation provoked by excessive thyroxine, hypertension and moderate OSA diagnosed on several polysomnograms. He had been treated previously with nasal and palatal surgery, oral appliances and PAP. DISE revealed complete anteroposterior collapse of the palate and tongue base, but also central apneas during baseline breathing and at low PAP levels. Polysomnogram performed following his DISE confirmed central sleep apnea which was positional in nature. He chose to undergo positional therapy instead of PAP or phrenic nerve stimulation. Conclusion The nasal flow and respiratory effort measurements included in our enhanced DISE setup enable the sleep surgeon to recognize the absence of respiratory effort even in the face of soft tissue collapse observed on videoendoscopy. These cases demonstrate the ability of propofol to preserve pathophysiologic mechanisms of sleep apnea (i.e. central versus obstructive), and underscore the importance of DISE as a diagnostic tool prior to sleep surgery. Support (If Any) NIH 1R01HL144859-01

Fraction of apnea is associated with the required continuous positive airway pressure level and reflects upper airway collapsibility in patients with obstructive sleep apnea.

We aimed to determine whether the fraction of apnea (Fapnea) could be used as an alternative index to reflect upper airway collapsibility. We retrospectively recruited 161 patients (16 women, mean age 47.8 years, body mass index [BMI] 28.0 kg/m2, and apnea-hypopnea index 46.4 events/h) with moderate to severe obstructive sleep apnea who had undergone nasal continuous positive airway pressure (CPAP) titration. Fapnea is defined as the percentage of apneic events relative to the total number of apneic and hypopneic events during sleep in a supine position on diagnostic polysomnography. We randomly split the data (70/30) into the development and validation datasets. In the development dataset, we conducted a multiple regression analysis to assess the association of variables, including age, sex, BMI, supine rapid eye movement (REM) sleep apnea-hypopnea index, and apnea with a CPAP level during supine REM sleep (REM_CPAP). Moreover, we developed an equation for predicting the CPAP level. Thereafter, we evaluated the correlation between the actual CPAP level and the value calculated using the model. BMI and Fapnea were the only significant factors that predicted the REM_CPAP level (adjusted r = .60, P < .001) in the development dataset. The validation data revealed a significant correlation between the actual and predicted CPAP levels (r = .69, P < .0001). We observed similar associations during supine non-REM sleep. Fapnea could significantly predict the CPAP levels during both REM and non-REM sleep, which likely reflects the upper airway collapsibility, independent of the BMI. Nakayama H, Takei Y, Kobayashi M, Yanagihara M, Inoue Y. Fraction of apnea is associated with the required continuous positive airway pressure level and reflects upper airway collapsibility in patients with obstructive sleep apnea. J Clin Sleep Med. 2022;18(5):1243-1249.

Positive Airway Pressure at Extubation Minimizes Subglottic Secretion Leak In Vitro.

Accumulated secretion above the endotracheal tube cuff can be aspirated during extubation after deflation. The possible techniques for minimizing pulmonary aspiration from subglottic secretion during extubation have not been well explored. This study aimed to determine the effect of different extubation techniques on secretion leakage. An endotracheal tube was placed in a tube mimicking an airway. We measured the leak volume of water or artificial sputum of different viscosities with three extubation techniques—negative pressure with suctioning; positive pressure with a resuscitator; and continuous positive airway pressure set at 5, 10, and 20 cm H2O. Extubation with continuous positive airway pressure resulted in lower secretion leakage than that with negative pressure with suctioning and positive pressure with a resuscitator. Increasing the continuous positive airway pressure level decreased secretion leakage volume during extubation. We further determined a correlation of leak volume with sputum viscosity. Continuous positive airway pressure at 5 cm H2O produced lower volume secretion leakage than the other two techniques, even with higher secretion viscosity. Based on these results, using continuous positive airway pressure with a previous ventilator continuous positive airway pressure/positive end-expiratory pressure setting for extubation is recommended.

A study on noninvasive ventilation in Type-II respiratory failure in a tertiary care center

Background: Type II respiratory failure is a common complication with considerable morbidity and mortality. Noninvasive ventilation (NIV) has been used preferentially with better results. The objective of this study was to assess the outcome and complications of NIV in type II respiratory failure patients. Methods: A clinical observational study of 67 consecutive adult patients with Type II respiratory failure who were assigned NIV, fulfilling inclusion and exclusion criteria were recruited in the study. NIV Bi level positive airway Pressure (Bi PAP) (spontaneous mode) was used in all patients with settings of 12/6 initially. Based on arterial blood gas values and clinical status, settings were adjusted and followed up as per British Thoracic Society guidelines (2016). In case of worsening of mental status, deterioration of potential of hydrogen (PH), increased partial pressure of carbon dioxide, and intolerance to NIV, patients were subjected to invasive ventilation within the first 4 h of NIV initiation. Results: Patients diagnosed with acute exacerbation of chronic obstructive pulmonary disease (–92.5%), and cases of obstructive sleep apnea (7.5%), showed significant improvement in NIV trial over 24 h in 91.7% and 100%, respectively, by the way of reduction of PCO2 levels and improvement in partial pressure of oxygen, oxygen saturation, which was statistically significant in 89.5% of patients. Clinical improvement noted by the decrease in heart rate, respiratory rate was also statistically significant with a P < 001. However, PH did not show significant changes in our study. Conclusions: A trial of NIV is a useful alternative to mechanical ventilation in many different situations with Type II respiratory failure. Advantages of cost-effectiveness, minimal utilization of intensive care unit resources, low morbidity and mortality rates with patient-friendly equipment features contribute to its preference over invasive ventilation.

Different Continuous Positive Airway Pressure Titration Modalities in Obstructive Sleep Apnea Syndrome Patients.

BackgroundPatients with obstructive sleep apnea syndrome are mainly treated with continuous positive airway pressure. Polysomnography-guided full-night manual titration is the gold standard for continuous positive airway pressure titration, but it is cost-, time-, and effort-consuming. Alternative ways of titration are easier with less cost, time, and effort. In the era of the COVID-19 pandemic, the need to establish more safe strategies is increased.AimTo choose a rapid, efficient, simple, and safe method with less effort and cost in the measurement of a suitable level of positive airway pressure in the management of obstructive sleep apnea syndrome.MethodsThis study enrolled 48 adult patients who had been diagnosed with obstructive sleep apnea syndrome at our sleep unit and were candidates for treatment with continuous positive airway pressure according to AASM 2008 after exclusion of other sleep-related breathing disorders. All patients underwent both laboratory full-night manual titration and auto-titration (by Prisma20A of WEINMANN medical technology, Germany). Manual titration pressure and P95 of auto-titration were obtained and compared with calculated pressures by five predictive formulas (Miljeteig and Hoffstein, Sériès, Stradling, Loredo, and Lee).ResultsPatients included in the study were 25 females (52.1%) and 23 males (47.9%) with a mean±SD of age of 49.98±10.36 years. Mean±SD of manual pressure was 10.44±2.49 cmH2O, P95 was 10.16±2.64 cmH2O, and calculated pressures by different equations were: Miljeteig and Hoffstein, 8.53±2.03; Sériès, 11.40±1.81; Stradling, 9.68±1.65; Loredo, 9.90±1.79; and Lee, 10.61±2.68 cmH2O. No significant differences were reported between manual pressure and pressures of auto-titration with Sériès, Stradling, Loredo, and Lee equations (p=0.112, 0.09, 0.212, 0.213, and 0.657, respectively).ConclusionAuto-titration can be used as an effective alternative to manual titration with less cost and effort and is more comfortable to patients. Predictive formulas can be used instead of standard and auto-titration especially in resource-limited facilities and in pandemics.