One-Year Adherence to Continuous Positive Airway Pressure With Telemonitoring in Sleep Apnea Hypopnea Syndrome: A Randomized Controlled Trial

Study Objective: Telemedicine (TM) for continuous positive airway pressure (CPAP) treated patients may save health-care resources without compromising treatment effectiveness. We assessed the effect of TM (AirView Online System, ResMed) during the CPAP habituation phase on 3-month and 1-year treatment adherence and efficacy in patients with moderate-to-severe obstructive sleep apnea (OSA).

Methods: At CPAP initiation, 120 patients diagnosed with OSA were randomized to either usual care (UC) or TM during the habituation phase (clinical registration: ISRCTN12865936). Both groups received a first face-to-face appointment with a sleep care giver at CPAP initiation. Within the following month, 2 other physical visits were scheduled in the UC group whereas two phone consultations were planned in the TM group, in which CPAP parameters were remotely adapted. Additional physical visits were programmed at the patient's request. Face-to-face consultations were scheduled at 3 and 12 months after CPAP initiation. The primary outcome was the mean CPAP daily use over the course of 12 months.

Results: Twenty of 60 patients stopped CPAP therapy in the UC group vs. 14 of 60 in the TM group (p = 0.24). In per protocol analysis, mean [95% CI] daily CPAP use among 86 patients still using CPAP at 12 months was 279 [237; 321] min in the 38 patients on UC and 279 [247; 311] min in the 43 patients on TM, mean difference [95% CI]: 0 [−52; 52] min, P = 0.99. Total consultation time per patient was not different between groups, TM: 163 [147; 178] min, UC: 178 [159; 197] min, difference: −15 [−39; 9] min, p = 0.22.

Conclusions: Telemedicine during the CPAP habituation phase did not alter daily CPAP use or treatment adherence and did not require more healthcare time. Telemedicine may support clinic attendance for CPAP titration.

Clinical Trial Registration: [ISRCTN], identifier [ISRCTN12865936].

Copeptin, pro-atrial natriuretic peptide and pro-adrenomedullin as markers of hypoxic stress in patients with obstructive sleep apnea-a prospective intervention study

Study Objectives

Obstructive sleep apnea (OSA) might lead to oxidative stress, inflammation and elevated circulating copeptin, proANP and proADM levels. We aimed to evaluate whether the levels of these prohormones are higher in patients with OSA and whether they might change under continuous positive airway pressure (CPAP) therapy, serving as potential proxies for the diagnosis and therapy-response in OSA.

Methods

A total of 310 patients with suspicion of OSA were recruited. Screening for OSA was performed using overnight pulse oximetry followed by polygraphy and a venous puncture in the morning. All patients diagnosed with OSA underwent CPAP adaptation. A venous puncture was conducted in the night before CPAP and in the following morning. At 1 and 6 months of treatment, polygraphy was performed, followed by a venous puncture in the morning. In the acquired blood, copeptin, proANP and proADM levels were measured.

Results

We analyzed 232 patients with OSA and 30 patients without OSA. Our results indicated that only copeptin levels differed significantly among patients with and without OSA at baseline. In OSA patients, the levels of proADM significantly changed after 1 and 6 months on CPAP therapy, when compared to baseline (p < 0.001 and p = 0.020). Additionally, proANP levels significantly decreased after 12 h on CPAP therapy, as compared to baseline levels (p < 0.001).

Conclusions

Copeptin is significantly associated with the presence of OSA. ProANP levels might serve as a potential proxy for the acute response to non-invasive ventilation (12 h), while proADM reflects the long-term response (1 and 6 months).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01704-0.

Nursing postoperative lung cancer patients using continuous positive airway pressure treatment

OBJECTIVE

This study aimed to investigate the nursing of postoperative lung cancer patients treated with continuous positive airway pressure (CPAP).

METHODS

A total of 64 lung cancer patients in our hospital were recruited as the study cohort and randomly divided into a CPAP group and a control group. The patients in the CPAP group (n=30) were administered CPAP, while those in the control group (n=34) were given routine low flow oxygen inhalation, a respiratory stimulant, a bronchodilator, antibiotics, antitussives, anti-inflammatories (glucocorticoids), an apophlegmatisant (ambroxol), basic nutritional support, correcting acidosis, etc. Results: The patients in the CPAP group showed a more significant improvement in their blood gas analysis, and they also had better airway patency and secretion cleaning effects compared with those in the control group. One month after the treatment, the patients in the CPAP group had significantly less inappetence, weight loss, electrolyte disturbance, dyspnea, and pulmonary encephalopathy than the patients in the control group. One week after the treatment, the patients in the CPAP group had higher maximum ventilatory volumes (MVV), higher maximum mid-expiratory flows (MMF), higher forced expiratory volumes in 1s/forced vital capacity (FEV1/FVC), higher peak expiratory flows (PEF), and higher total lung capacity (TLC) than the patients in the control group.

CONCLUSION

CPAP can significantly improve postoperative dyspnea in lung cancer patients.

Lower socioeconomic status and co-morbid conditions are associated with reduced continuous positive airway pressure adherence among older adult medicare beneficiaries with obstructive sleep apnea

STUDY OBJECTIVES

To examine rates of adherence to continuous positive airway pressure (CPAP) therapy among a representative sample of older adult Medicare beneficiaries with obstructive sleep apnea (OSA), and to identify demographic and health-related factors associated with CPAP adherence.

METHODS

Using a 5% sample of Medicare claims data, we utilized Medicare policy and CPAP machine charges as a proxy for CPAP adherence. A cumulative logit model was used to identify demographic, medical, and psychiatric predictors of CPAP adherence status.

RESULTS

Of beneficiaries who initiated CPAP (n = 3,229), 74.9% (n = 2,417) met the so-called "90-day Medicare adherence criteria," but only 58.8% of these individuals (n = 1,420) continued to use CPAP throughout the entire 13-month rent-to-own period. Anxiety, anemia, fibromyalgia, traumatic brain injury, and lower socioeconomic status (SES) were all associated with reduced CPAP adherence.

CONCLUSIONS

These results provide the first national estimates of CPAP adherence among older adult Medicare beneficiaries in the United States. In addition, findings highlight the salience of medical and psychiatric comorbidity, as well as SES, as important markers of CPAP adherence among older adults in the United States. Future studies should seek to evaluate interventions to improve CPAP adherence among older adults of lower SES.

Plasma exosomes in OSA patients promote endothelial senescence: effect of long-term adherent continuous positive airway pressure

Obstructive sleep apnea (OSA) is associated with increased risk for end-organ morbidities, which can collectively be viewed as accelerated aging. Vascular senescence is an important contributor to end-organ dysfunction. Exosomes are released ubiquitously into the circulation, and transfer their cargo to target cells facilitating physiological and pathological processes. Plasma exosomes from 15 patients with polysomnographically diagnosed OSA at baseline (OSA-T1) after 12 months of adherent continuous positive airway pressure (CPAP) treatment (OSA-T2), 13 untreated OSA patients at 12-month intervals (OSA-NT1, OSA-NT2), and 12 controls (CO1 and CO2) were applied on naïve human microvascular endothelialcells-dermal (HMVEC-d). Expression of several senescence gene markers including p16 (CDKN2A), SIRT1, and SIRT6 and immunostaining for β-galactosidase activity (x-gal) were performed. Endothelial cells were also exposed to intermittent hypoxia (IH) or normoxia (RA) or treated with hydrogen peroxide (H2O2), stained with x-gal and subjected to qRT-PCR. Exosomes from OSA-T1, OSA-NT1, and OSA-NT2 induced significant increases in x-gal staining compared to OSA-T2, CO1, and CO2 (p-value < 0.01). p16 expression was significantly increased (p < 0.01), while SIRT1 and SIRT6 expression levels were decreased (p < 0.02 and p < 0.009). Endothelial cells exposed to IH or to H2O2 showed significant increases in x-gal staining (p < 0.001) and in senescence gene expression. Circulating exosomes in untreated OSA induce marked and significant increases in senescence of naïve endothelial cells, which are only partially reversible upon long-term adherent CPAP treatment. Furthermore, endothelial cells exposed to IH or H2O2 also elicit similar responses. Thus, OSA either directly or indirectly via exosomes may initiate and exacerbate cellular aging, possibly via oxidative stress-related pathways.

Obstructive sleep apnea and CPAP therapy alter distinct transcriptional programs in subcutaneous fat tissue

Obstructive sleep apnea (OSA) has been linked to dysregulated metabolic states, and treatment of sleep apnea may improve these conditions. Subcutaneous adipose tissue is a readily samplable fat depot that plays an important role in regulating metabolism. However, neither the pathophysiologic consequences of OSA nor the effects of continuous positive airway pressure (CPAP) in altering this compartment's molecular pathways are understood. This study aimed to systematically identify subcutaneous adipose tissue transcriptional programs modulated in OSA and in response to its effective treatment with CPAP. Two subject groups were investigated: Study Group 1 was comprised of 10 OSA and 8 controls; Study Group 2 included 24 individuals with OSA studied at baseline and following CPAP. For each subject, genome-wide gene expression measurement of subcutaneous fat was performed. Differentially activated pathways elicited by OSA (Group 1) and in response to its treatment (Group 2) were determined using network and Gene Set Enrichment Analysis (GSEA). In Group 2, treatment of OSA with CPAP improved apnea-hypopnea index, daytime sleepiness, and blood pressure, but not anthropometric measures. In Group 1, GSEA revealed many up-regulated gene sets in OSA subjects, most of which were involved in immuno-inflammatory (e.g. interferon-γ signaling), transcription, and metabolic processes such as adipogenesis. Unexpectedly, CPAP therapy in Group 2 subjects was also associated with up-regulation of several immune pathways as well as cholesterol biosynthesis. Collectively, our findings demonstrate that OSA alters distinct inflammatory and metabolic programs in subcutaneous fat, but these transcriptional signatures are not reversed with short-term effective therapy.

Pressure adjustment is the most useful intervention for improving compliance in telemonitored patients treated with CPAP in the first 6 months of treatment

PURPOSE

Telemonitoring (TMg) for patients treated with continuous positive airway pressure (CPAP) is now routine care in some sleep labs. The purpose of the present study was to identify technical interventions associated with improved CPAP compliance in a real-life cohort of newly telemonitored patients with obstructive sleep apnea (OSA) during the first 6 months of treatment.

METHODS

All patients with moderate-to-severe OSA (apnea-hypopnea index (AHI) ≥ 15/h) who were newly treated with CPAP were included in the study and telemonitored. A group educational session was scheduled after 1 month. Technical interventions were performed at the patient's request and during scheduled visits and the impact of each intervention on CPAP therapy compliance was collected.

RESULTS

Between May 2018 and Dec 2019, 349 patients newly diagnosed with OSA were hospitalized in the sleep lab for CPAP titration and 212 patients were included (mean age 54.6 ± 13.1 years, mean BMI 31.7 ± 5.8 kg/m², mean AHI 42.8 ± 22.0). TMg acceptance rate was 87%. Mean 6-month compliance was 275 ± 154 min, 13% stopped CPAP, and 17% were non-compliant. Correlations were observed between BMI (r = 0.15, p = 0.029), median and 95th percentile leaks (r = -0.23 and -0.18, p = 0.016 and 0.002), and CPAP compliance. During follow-up, 92 interventions were required, mainly for mask change (n = 80). Pressure modification (n = 16) was the only intervention that increased CPAP use > 30 min/night, p = 0.021.

CONCLUSION

Pressure modification was the only adaptation that significantly increased CPAP compliance during the first 6 months. Remote TMg allows providing daily, accurate, and immediate feedback that could help clinicians to confirm that the CPAP treatment is effective.

Loss of CPAP causes sustained EGFR signaling and epithelial-mesenchymal transition in oral cancer

Higher epidermal growth factor receptor (EGFR) signaling can contribute to tumor metastasis and resistance to therapies in oral squamous cell carcinoma (OSCC). EGFR signaling can promote epithelial-mesenchymal transition (EMT) in OSCC. EMT is a process by which epithelial cells acquire invasive properties and it can contribute to tumor metastasis. Not only do the abnormal functions of microtubule and microtubule-organizing centers (MTOC) such as centrosomes lead to cancers, but also the malignant tissues are characterized by aberrant centriolar features and amplified centrosomes. Microtubule inhibition therapies increase the sensitivity to EGFR targeting drugs in various cancers. In this study, we show that the loss of expression of a microtubule/tubulin binding protein, centrosomal protein 4.1-associated protein (CPAP), which is critical for centriole biogenesis and normal functioning of the centrosome, caused an increase in the EGFR levels and its signaling and, enhanced the EMT features and invasiveness of OSCC cells. Further, depletion of CPAP enhanced the tumorigenicity of these cells in a xeno-transplant model. Importantly, CPAP loss-associated EMT features and invasiveness of multiple OSCC cells were attenuated upon depletion of EGFR in them. On the other hand, we found that CPAP protein levels were higher in EGF treated OSCC cells as well as in oral cancer tissues, suggesting that the frequently reported aberrant centriolar features of tumors are potentially a consequence, but not the cause, of tumor progression. Overall, our novel observations show that, in addition to its known indispensable role in centrosome biogenesis, CPAP also plays a vital role in suppressing tumorigenesis in OSCC by facilitating EGFR homeostasis.

Comparison of High-Flow Humidified Oxygen With Conventional Continuous Positive Airway Pressure in Nonventilated Lungs During Thoracic Surgery: A Randomized Cross-Over Study

OBJECTIVE

This study assessed the efficacy of high-flow humidified oxygen (HFHO) as an alternative to continuous positive airway pressure (CPAP) for improving oxygenation while preserving nonventilated lung collapse during one-lung ventilation.

DESIGN

A prospective randomized cross-over trial.

SETTING

A tertiary medical center.

PARTICIPANTS

The study comprised 28 patients undergoing elective thoracotomy with one-lung ventilation using a double-lumen endobronchial tube placement.

INTERVENTIONS

The patients received prophylactic CPAP or HFHO to the nonventilated lung for 20 minutes and were then crossedover to the other oxygenation modality for 20 minutes, with a 20-minute recovery interval between the two modalities.

MEASUREMENTS AND MAIN RESULTS

Changes in respiratory parameters and lung deflation quality were recorded. Both CPAP and HFHO increased the partial pressure of arterial oxygen in either sequence in both groups, ranging from 31.8-to-66.0 mmHg. However, the increments from these two interventions were not statistically significant (95% confidence interval -12.84 to 21.87; p = 0.597). There were no differences in other parameters. Half the patients receiving CPAP experienced worsening of the surgical condition, whereas the HFHO patients experienced no change or reported a better lung deflation (p < 0.001).

CONCLUSION

HFHO could be an alternative method to CPAP for improving arterial oxygenation while preserving lung deflation during one-lung ventilation. However, additional studies are warranted in regard to its cost-effectiveness and establishment as a routine treatment.

Predictor Factors of Continuous Positive Airway Pressure Failure in Preterm Infants with Respiratory Distress

Respiratory distress contributes significantly to mortality, and morbidity in preterm infants. The incidence of nasal continuous positive airway pressure (CPAP) failure is remarkably high. There are limited data available regarding nasal CPAP failure in Indonesia, and this study is expected to be a reference in taking preventive measures to reduce mortality and morbidity in preterm infants. To determine predictive factors of nasal CPAP failure in preterm infants with respiratory distress. A retrospective cohort study was conducted in preterm infants with respiratory distress at the Neonatology ward of Dr. Sardjito Hospital during January 2017-July 2019. Chi-square or Fisher's exact tests, followed by multivariate logistic regression analysis with backward method, was used to identify factors contributing to nasal CPAP failure. A total of 150 infants were included in this study. Fifty-three (37.8%) infants had nasal CPAP failure. Bivariate analysis showed birth weight <1000 g, singleton, APGAR score 4-7, premature rupture of membrane (PROM), Downes score, and initiation of fractional concentration of inspired (FiO2) requirement were all risk factors of nasal CPAP failure. However, only birth weight <1000 g (P = .022; OR 2.69; CI 95% 1.34-5.44), initial Downes score (P = .035; OR 2.68; CI 95% 3.10-24.11), and initiation of FiO2 requirement ≥30% (P = .0001; OR 3.03; CI 95% 2.04-4.50) were significant predictors for nasal CPAP failure by multivariate analysis. Birth weight <1000 g, singleton, initial Downes score, and initiation of FiO2 requirement >30% were significant predictors of nasal CPAP failure in preterm infants with respiratory distress.

Original and minimally invasive approach to a left-lung refractary atelectasis after reparation of an aortic recoarctation in a lactant: Selective endobronchial CPAP

Atelectasis is one of the most common respiratory complications in pediatric patients after open-heart surgery, and may lead to weaning failure and increased morbidity. We report the use of an original, minimally invasive approach to refractory left lung atelectasis after repair of an aortic coarctation in a 2 month-old infant, in which a CPAP system connected to a flexible endobronchial tube resolved the atelectasis.

Respiratory activity of the cricopharyngeus muscle in the neonatal period

While phasic electrical activity of the cricopharyngeus muscle (EAcp)-the main component of the upper esophageal sphincter-occurs with inspiration and forceful expiration in adults, no such data is available for newborns. In addition, the effect of nasal respiratory support commonly used in newborns is unknown. We aimed to describe the phasic respiratory EAcp and to assess the potential effect of nasal CPAP (nCPAP, 6 cmH₂O) or high-flow nasal cannula (HFNC, 7 L/min) in newborn lambs during 6-h recordings. Phasic EAcp was present in 11/17 lambs, including in 32 % (25, 81) [(median (Q1, Q3)] of respiratory cycles in wakefulness, 40 % (27, 70) in NREM sleep, and 10 % (0, 23) in REM sleep. In addition, EAcp was observed only during post-inspiration and/or expiration. Nasal CPAP or HFNC assessed in 7 of the 17 lambs did not have any effect. We conclude that phasic respiratory EAcp occurs in post-inspiration and expiration in newborn lambs.

Evaluation of Obstructive Sleep Apnea Phenotypes Treatment Effectiveness

Background and Objective: Obstructive sleep apnea (OSA) is a heterogeneous chronic sleep associated disorder. A common apnea-hypopnea index (AHI)-focused approach to OSA severity evaluation is not sufficient enough to capture the extent of OSA related risks, it limits our understanding of disease pathogenesis and may contribute to a modest response to conventional treatment. In order to resolve the heterogeneity issue, OSA patients can be divided into more homogenous therapeutically and prognostically significant groups-phenotypes. An improved understanding of OSA phenotype relationship to treatment effectiveness is required. Thus, in this study several clinical OSA phenotypes are identified and compared by their treatment effectiveness. Methods and materials: Retrospective data analysis of 233 adult patients with OSA treated with continuous positive airway pressure (CPAP) was performed. Statistical analysis of data relating to demographic and anthropometric characteristics, symptoms, arterial blood gas test results, polysomnografic and respiratory polygraphic tests and treatment, treatment results was performed. Results: 3 phenotypes have been identified: "Position dependent (supine) OSA" (Positional OSA), "Severe OSA in obese patients" (Severe OSA) and "OSA and periodic limb movements (PLM)" (OSA and PLM). The highest count of responders to treatment with CPAP was in the OSA and PLM phenotype, followed by the Positional OSA phenotype. Treatment with CPAP, despite the highest mean pressure administered was the least effective among Severe OSA phenotype. Conclusions: Different OSA phenotypes vary significantly and lead to differences in response to treatment. Thus, treatment effectiveness depends on OSA phenotypes and treatment techniques other than CPAP may be needed. This emphasizes the importance of a more individualized approach when treating OSA.

The effect of non-benzodiazepine sedative hypnotics on CPAP adherence in patients with OSA: a systematic review and meta-analysis

STUDY OBJECTIVES

This meta-analysis aimed to explore the effect of non-benzodiazepine sedative hypnotics (NBSH) on continuous positive airway pressure (CPAP) adherence in patients with obstructive sleep apnea (OSA).

METHODS

We conducted a systematic search through PubMed, Medline, the Cochrane Library, EMBASE, Scopus and ClinicalTrials (all searched from inception to 15 August 2020). Publications were limited to articles, clinical conferences and letters, including randomized controlled trials and retrospective studies. We used a random-effects model to calculate the odds ratio (OR) and mean difference (MD) with corresponding confidence interval (CI). Subgroup analyses were conducted to analyze the sources of heterogeneity.

RESULTS

Eight studies fulfilled the inclusion and exclusion criteria for patients newly diagnosed with obstructive sleep apnea. Overall, the use of NBSH was associated with increased use of CPAP per night (MD = 0.62 h; 95% CI = 0.26-0.98) and use for more nights (MD = 12.08%; 95% CI = 5.27-18.88). When a study seriously affecting heterogeneity was removed, more patients adhered well with CPAP use (pooled OR = 2.48; 95% CI = 1.75-3.52) with good adherence defined as CPAP use for＞4 h/night on＞70% of nights. Among prescribed NBSHs, eszopiclone showed the most significant effect on CPAP adherence.

CONCLUSION

CPAP adherence may increase in OSA patients treated with non-benzodiazepine sedative hypnotics especially eszopiclone. The effect of zolpidem and zaleplon on CPAP adherence requires further investigation by larger scale, randomized, controlled trials.

Obstructive Sleep Apnea Treatment and Dementia Risk in Older Adults

STUDY OBJECTIVES

To examine associations between PAP therapy, adherence and incident diagnoses of Alzheimer's disease (AD), mild cognitive impairment (MCI), and dementia not-otherwise-specified (DNOS) in older adults.

METHODS

This retrospective study utilized Medicare 5% fee-for-service claims data of 53,321 beneficiaries, aged 65+, with an OSA diagnosis prior to 2011. Study participants were evaluated using ICD-9 codes for neurocognitive syndromes [AD(n=1,057), DNOS(n=378), and MCI(n=443)] that were newly-identified between 2011-2013. PAP treatment was defined as presence of ≥1 durable medical equipment (HCPCS) code for PAP supplies. PAP adherence was defined as ≥2 HCPCS codes for PAP equipment, separated by≥1 month. Logistic regression models, adjusted for demographic and health characteristics, were used to estimate associations between PAP treatment or adherence and new AD, DNOS, and MCI diagnoses.

RESULTS

In this sample of Medicare beneficiaries with OSA, 59% were men, 90% were non-Hispanic whites and 62% were younger than 75y. The majority (78%) of beneficiaries with OSA were prescribed PAP (treated), and 74% showed evidence of adherent PAP use. In adjusted models, PAP treatment was associated with lower odds of incident diagnoses of AD and DNOS (OR=0.78, 95% CI:0.69-0.89; and OR=0.69, 95% CI:0.55-0.85). Lower odds of MCI, approaching statistical significance, were also observed among PAP users (OR=0.82, 95% CI:0.66-1.02). PAP adherence was associated with lower odds of incident diagnoses of AD (OR=0.65, 95% CI:0.56-0.76).

CONCLUSIONS

PAP treatment and adherence are independently associated with lower odds of incident AD diagnoses in older adults. Results suggest that treatment of OSA may reduce risk of subsequent dementia.

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy

INTRODUCTION

Obstructive sleep apnea (OSA) results in chronic intermittent hypoxia leading to systemic inflammation, increases in pro-inflammatory cytokines TNF-Alpha and IL-6, and increased risk for a number of life threatening medical disorders such as cardiovascular and kidney disease.

METHODS

A BioPlex Array was used to examined the serum levels of four cytokines also expressed in endothelial cells and/or macrophages and associated with cardiovascular and kidney disease risk.

RESULTS

Relative to untreated OSA patients, airways treated OSA patients had a 5.4-fold higher median level of MMP2 (p = 9.1x10-11), a 1.4-fold higher level of TWEAK (p = 1.8x10-7), a 1.7-fold higher level of CD163 (p = 1.4x10-6), but a 2.0-fold lower level of MMP3 (p = 7.9x10-7). Airway treatment resulted in levels more similar to or indistinguishable from control subjects. Both t-SNE or UMAP analysis of the global structure of these multi-dimensional data revealed two data clusters, one populated primarily with data for controls and most airways treated OSA patients and a second populated primarily with data for OSA patients.

DISCUSSION

We discuss a concept in which the aberrant levels of these cytokines in untreated OSA patients may represent a chronic response after years of experiencing intermittent nightly hypoxia, which attenuated the acute response to hypoxia. A balanced therapeutic correction of the aberrant levels of these cytokines may limit the progression of CVD and kidney disease in OSA patients.

Pneumomediastinum in patients with SARS-CoV-2 treated with non-invasive ventilation

SARS-CoV-2, causing the pandemic COVID-19, has rapidly spread, overwhelming healthcare systems. Non-invasive positive pressure ventilation (NIV) can be used as a bridging therapy to delay invasive mechanical ventilation or as a standalone therapy. Spontaneous pneumomediastinum is rare and self-limiting, but there is an increased incidence documented in COVID-19.

Here we document two cases of pneumomediastinum-related prolonged NIV therapy in severe COVID-19. Patient 1, a 64-year-old man, who developed symptoms after NIV therapy was weaned and survived. Patient 2, an 82-year-old woman, failed to improve despite NIV therapy, on investigation was found to have a pneumomediastinum. After review, the patient was placed on best supportive care and died 3 days later.

We highlight the importance of recognising less common causes of deterioration in severe COVID-19 treated with NIV. In addition, pneumomediastinum in these cases may not always lead to poor outcomes.

The Role of Positive Airway Pressure Therapy in Adults with Obesity Hypoventilation Syndrome. A Systematic Review and Meta-Analysis

Rationale: Obesity hypoventilation syndrome (OHS) is an undesirable complication of severe obesity. Although weight loss is an accepted component of management, it is difficult to achieve and sustain the degree of weight loss necessary to reverse OHS. As such, positive airway pressure (PAP) during sleep has become the cornerstone therapy for most patients with OHS. However, the value of PAP therapy remains uncertain.Objective: To perform a systematic review to determine whether adults with OHS should be treated with PAP therapy or not.Methods: This systematic review informed an international, multidisciplinary panel of experts who had converged to develop a clinical practice guideline on OHS for the American Thoracic Society. MEDLINE, the Cochrane Library, and Embase were searched from January 1946 to March 2019 for studies that compared PAP therapy (i.e., continuous PAP or noninvasive ventilation) to no PAP therapy in patients with OHS. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to appraise the quality of evidence.Results: The search identified 2,994 unique articles. The full text of 56 articles was reviewed, and 25 studies were selected, including 3 randomized trials, 12 nonrandomized comparative studies, and 10 randomized and nonrandomized studies without a comparator group. Sample size ranged from 21 to 1,527 patients. PAP was associated with increased resolution of OHS and improvements in mortality, gas exchange, daytime sleepiness, sleep quality, quality of life, and emergency department visits. Nearly half of patients experienced trivial adverse effects related to PAP therapy. Certainty in the estimated effects was low or very low for most outcomes.Conclusions: The panel made a conditional (i.e., weak) recommendation that PAP therapy during sleep be offered to patients with OHS to improve outcomes. This recommendation was based on very low-quality evidence.

The rapid development and deployment of a new multidisciplinary CPAP service outside of a critical care environment during the early stages of the COVID-19 pandemic

The COVID-19 pandemic has led to a dramatic increase in patients presenting with type 1 respiratory failure. In order to protect our limited critical care capacity, we rapidly developed a new ward-based inpatient continuous positive airway pressure (CPAP) service with direct input from the respiratory, infectious diseases and critical care teams. Close collaboration between these specialties and new innovative solutions were required to facilitate this. CPAP equipment (normally reserved for domiciliary care) was adapted to reduce the pressure on our strained oxygen infrastructure. Side rooms on the infectious diseases ward were swiftly converted into new negative pressure areas using temporary installed ventilatory equipment, reducing the viral aerosol risk for staff. Novel patient monitoring solutions were used to protect staff while also ensuring patient safety. Staff training and specialist oversight was organised within days. The resulting service was successful, with over half (17/26 (65%)) of patients avoiding invasive ventilation.

Successful use of CPAP in a pregnant patient with COVID-19 pneumonia

A 35-year-old nurse, who was 27 weeks pregnant at the time, was admitted to hospital with a short history of cough, fever and worsening shortness of breath. Oral and nasopharyngeal swabs were positive for SARS-CoV-2 on real-time viral PCR. During her admission, her breathing further deteriorated and she developed type 1 respiratory failure. A decision was made to trial treatment with continuous positive airway pressure (CPAP) as a means of avoiding intubation. The patient tolerated this well and made rapid improvements on this therapy. She was quickly weaned off and fully recovered before being discharged home. This case highlights the potential for CPAP to be used as a means of avoiding mechanical ventilation and iatrogenic preterm birth in COVID-19 pneumonia in pregnancy. Furthermore, it highlights the need for robust evidence to support this treatment.

Continuous Positive Airway Pressure Improves Renal Function in Obese Patients With Obstructive Sleep Apnea Syndrome

Background: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for cardiovascular morbidity and mortality, and it has a detrimental effect on renal function. Obesity is the major risk factor for OSAS, and represents a risk factor for chronic kidney disease. Continuous positive airway pressure (CPAP) is the suggested therapy for moderate-to-severe OSAS. We designed this study to evaluate the effect of CPAP on estimated glomerular filtration rate (e-GFR) in a cohort of obese patients with moderate-to-severe OSAS and normal renal function. Methods: We enrolled 198 obese subjects, divided into two groups (OSAS+ and OSAS-), on the basis of cardiorespiratory monitoring; mild OSAS patients (n = 33) were excluded from the study, thus the analyses were conducted on 165 patients. Comparisons between groups were made by Student t-test or χ² test as appropriate. Linear regression analyses were used to assess the relationship between baseline e-GFR and different covariates and, in the OSAS+ group, between Δe-GFR and different covariates. A multivariate regression analysis was performed to determinate the independent predictor of the Δe-GFR. Results: OSAS+ subjects showed significantly increased values of systolic blood pressure, HOMA, pulse wave velocity, high-sensitivity C reactive protein and uric acid compared with OSAS- group. OSAS+ group showed significantly lower values of e-GFR and increased values of microalbuminuria. At linear regression analysis e-GFR resulted significantly and inversely related to AHI in the whole study population and in the two groups. After 6 months of CPAP therapy, OSAS+ subjects showed an improvement in respiratory parameters, as well as a significant increase in e-GFR values (104.2 + 19.0 vs. 84.0 + 13.1 ml/min/1.73 m², P < 0.0001). At multiple regression analysis, Δ apnea/hypopnea index (AHIa) resulted the main independent predictor of Δe-GFR explaining 22% of its variation. Conclusions: Obese OSAS patients show significantly lower values of e-GFR, even if in the normal range, compared with obese non-OSAS subjects. After 6 months of CPAP, e-GFR significantly improved (+20 ml/min/1.73 m²) and ΔAHIa resulted the most important independent predictor of Δe-GFR.

Recommended Approaches to Minimize Aerosol Dispersion of SARS-CoV-2 During Noninvasive Ventilatory Support Can Cause Ventilator Performance Deterioration: A Benchmark Comparative Study

Background

SARS-CoV-2 aerosolization during noninvasive positive-pressure ventilation may endanger health care professionals. Various circuit setups have been described to reduce virus aerosolization. However, these setups may alter ventilator performance.

Research Question

What are the consequences of the various suggested circuit setups on ventilator efficacy during CPAP and noninvasive ventilation (NIV)?

Study Design and Methods

Eight circuit setups were evaluated on a bench test model that consisted of a three-dimensional printed head and an artificial lung. Setups included a dual-limb circuit with an oronasal mask, a dual-limb circuit with a helmet interface, a single-limb circuit with a passive exhalation valve, three single-limb circuits with custom-made additional leaks, and two single-limb circuits with active exhalation valves. All setups were evaluated during NIV and CPAP. The following variables were recorded: the inspiratory flow preceding triggering of the ventilator, the inspiratory effort required to trigger the ventilator, the triggering delay, the maximal inspiratory pressure delivered by the ventilator, the tidal volume generated to the artificial lung, the total work of breathing, and the pressure-time product needed to trigger the ventilator.

Results

With NIV, the type of circuit setup had a significant impact on inspiratory flow preceding triggering of the ventilator (P < .0001), the inspiratory effort required to trigger the ventilator (P < .0001), the triggering delay (P < .0001), the maximal inspiratory pressure (P < .0001), the tidal volume (P = .0008), the work of breathing (P < .0001), and the pressure-time product needed to trigger the ventilator (P < .0001). Similar differences and consequences were seen with CPAP as well as with the addition of bacterial filters. Best performance was achieved with a dual-limb circuit with an oronasal mask. Worst performance was achieved with a dual-limb circuit with a helmet interface.

Interpretation

Ventilator performance is significantly impacted by the circuit setup. A dual-limb circuit with oronasal mask should be used preferentially.

Characteristics and outcomes in hospitalized COVID-19 patients during the first 28 days of the spring and autumn pandemic waves in Milan: An observational prospective study

BACKGROUND

The therapeutic approach to COVID-19 and healthcare system preparedness improved during 2020. We compared characteristics and outcomes of hospitalized COVID-19 patients during the first 28 days of the March and October pandemic waves in Milan, Italy.

MATERIAL AND METHODS

A prospective, observational study enrolling adult patients hospitalized with COVID-19 pneumonia during March 7-April 4 (1st period) and October 15-November 12 (2nd period). During the 1st period hydroxychloroquine, lopinavir/ritonavir and therapeutic enoxaparin when thrombosis was confirmed were administered; systemic corticosteroids were given in case of severe pneumonia. During the 2nd period dexamethasone, methylprednisolone, remdesivir, thromboprophylaxis or anticoagulation were administered according to international recommendations. Patients with respiratory distress on oxygen masks initiated CPAP. Outcomes were: length of hospital stay, all-cause in-hospital mortality and need for intubation.

RESULTS

We included 70 patients (75% males) during the 1st and 76 patients (51% males, p = 0.522) during the 2nd period. Prevalence of severe respiratory failure (30% vs. 12%, p = 0.006), and D-dimer >3000 FEU (34% vs. 15%, P = 0.012) were reduced during the 2nd period, while anticoagulation and corticosteroids were more frequently administered (both p < 0.01). Mortality and time to referral were also reduced (39.4% vs. 22.4%, p = 0.019 and 6 vs. 5 days, p = 0.014), while need for intubation didn't change. Hospitalization length was comparable, but the proportion of patients discharged home was higher during the 2nd period (28.2% vs. 55.4%, p = 0.001).

CONCLUSIONS

Changing treatment paradigms and early referral might have reduced mortality in COVID-19 patients. The effects of specific therapeutic regimens needs further confirmation in future clinical studies.

Incidence of pulmonary embolism in patients with non-invasive respiratory support during COVID-19 outbreak

While the incidence of thrombotic complications in critically ill patients is very high, in patients under non-invasive respiratory support (NIS) is still unknown. The specific incidence of thrombotic events in each of the clinical scenarios within the broad spectrum of severity of COVID-19, is not clearly established, and this has not allowed the implementation of thromboprophylaxis or anticoagulation for routine care in COVID-19. Patients admitted in a semi-critical unit treated initially with NIS, especially Continuous-Positive Airway Pressure (CPAP), were included in the study. The cumulative incidence of pulmonary embolism was analyzed and compared between patients with good response to NIS and patients with clinical deterioration that required orotracheal intubation. 93 patients were included and 16% required mechanical ventilation (MV) after the NIS. The crude cumulative incidence of the PE was 14% (95%, CI 8-22) for all group. In patients that required orotracheal intubation and MV, the cumulative incidence was significantly higher [33% (95%, CI 16-58)] compared to patients that continued with non-invasive support [11% (CI 5-18)] (Log-Rank, p = 0.013). Patients that required mechanical ventilation were at higher risk of PE for a HR of 4.3 (95%CI 1.2-16). In conclusion, cumulative incidence of PE is remarkably higher in critically patients with a potential impact in COVID-19 evolution. In this context, patients under NIS are a very high-risk group for developing PE without a clear strategy regarding thromboprophylaxis.

How to improve CPAP failure prediction in preterm infants with RDS: a pilot study

We aimed to test the diagnostic accuracy in predicting continuous positive airway pressure (CPAP) failure in premature infants with respiratory distress syndrome (RDS) by integrating oxygen saturation (SpO₂)/fraction of inspired oxygen (FiO₂) (SF ratio) with the measurement of peak velocity of the right diaphragmatic excursions (RD-PV), during the inspiration (I-Peak) and expiratory (E-Peak) phases, performed by pulsed-wave Tissue Doppler imaging. This is a prospective, observational pilot study conducted over a 2-year period. Neonates at ≤ 32 weeks gestation supported by early CPAP were eligible. Natural surfactant was delivered via a minimally invasive technique. We performed serial measurements of SF ratio and RD-PV during the early post-natal hours to test the accuracy in predicting surfactant administration as well as invasive ventilation support within 72 h from birth because of the RDS worsening. Of 56 preterm infants enrolled, 34 (61%) failed CPAP support. SF ratio showed a significant inverse relationship with both Silverman-Andersen score at birth (rho = - 0.417; P = .001) and RD-PV [E-Peak] (rho = - 0.361; P = .007). We achieved a high accuracy in predicting CPAP failure (AUC = 95%; 95% CI, 89-100%) by integrating gender, SF ratio, and RD-PV [E-Peak] at the restricted, multivariate analysis.Conclusions: SF ratio and RD-PV, as measured by pulsed-wave Tissue Doppler, may help physicians to improve their confidence in optimizing therapeutic options in preterm infants with RDS. What is Known: • Continuous positive airway pressure is the recommended first-line treatment for respiratory distress syndrome in preterm infants, but failure rates remain unacceptably high. • Choosing the optimal treatment in terms of non-invasive ventilation effectiveness and timeliness of surfactant administration for these patients is often challenging, also due to our inability to identify a worsening respiratory failure. What is New: • The integration of oxygen saturation, as measured by SpO₂/FiO₂, with right diaphragm peak motion velocities, as measured by pulsed-wave tissue Doppler, allows for high prediction accuracy of non-invasive ventilation support failure in premature infants at risk of respiratory distress syndrome. • These measurements may help physicians in providing optimal supportive therapy for these patients.