CPAP Group Research Articles

Formyl peptide receptor 1 up-regulation and formyl peptide receptor 2/3 down-regulation of blood immune cells along with defective lipoxin A4/resolvin D1 production in obstructive sleep apnea patients.

BackgroundThis study aims to investigate the role of FPR 1/2/3 expressions in patients with obstructive sleep apnea (OSA).MethodWe made cross-sectional comparisons of FPR1/2/3 expressions of blood neutrophil, M1/M2a monocyte, and natural killer (NK) cell between 16 healthy subjects (HS), 16 primary snoring (PS) subjects, 46 treatment-naive OSA patients, and 18 severe OSA patients under long-term continuous positive airway pressure treatment (severe OSA on CPAP).ResultsFPR1 expressions on neutrophil were increased in treatment-naive OSA and severe OSA on CPAP groups versus either HS or PS. FPR2 expressions on neutrophil were decreased in treatment-naive OSA versus HS, and returned to normal in severe OSA on CPAP group. FPR1/FPR2 expression ratio on neutrophil was increased in treatment-naive OSA versus either HS or PS. Serum lipoxin A4, resolvin D1 levels, and FPR3 expressions of M1, M2a and NK cells were all decreased in treatment-naive OSA versus HS. OSA patients with hypertension had decreased FPR2 expressions on neutrophil and FPR3 expressions of NK cell. FPR1 expression, FPR1/FPR2 expression ratio on neutrophil, and FPR3 expression of M1 cell were all reversed after > 6-month CPAP treatment in 9 selected patients. In vitro intermittent hypoxia with re-oxygenation treatment in THP-1 cells resulted in increased FPR1/FPR2 expression ratio of M1 cells, and increased FPR1/FPR3 expression ratio of M2a cells.ConclusionsFPR1 over-expression and insufficiency of FPR2 and FPR3 in association with defective lipoxin A4 and resolving D1 production were associated with disease severity of OSA and its adverse consequences.

High-flow nasal cannula versus nasal continuous positive airway pressure for respiratory support in preterm infants: a meta-analysis of randomized controlled trials

Background: As a noninvasive respiratory support mode, high-flow nasal cannula (HFNC) is widely used in preterm infants at neonatal care units. HFNC is often used as an alternative to nasal continuous positive airway pressure (NCPAP) for initial or post-extubation respiratory support. The purpose of this meta-analysis is to evaluate and compare the efficacy and safety of HFNC and NCPAP for respiratory support in preterm infants.Methods: We searched PubMed, Web of Science, Embase, Cochrane Library, Clinicaltrials.gov, Controlled-trials.com, Google Scholar, VIP, and Wang Fang for articles from their inception to December 2018. All published randomized controlled trials (RCTs) evaluating and comparing the effects of HFNC and NCPAP therapy for primary respiratory support in newborns were included. All meta-analyses were performed using Review Manager 5.3.Results: In total, 21 RCTs involving 2886 preterm infants were included. The results of the meta-analysis revealed the following: (1) for primary respiratory support, the rates of treatment failure at trial entry were similar between HFNC and CPAP (relative risk 1.03, 95% confidence interval 0.79–1.33), and HFNC had reduced nasal trauma (p < .00001); and (2) for respiratory support after extubation, CPAP was associated with a lower likelihood of treatment failure than HFNC (relative risk 1.23, 95% confidence interval 1.01–1.50). The incidences of nasal trauma and pneumothorax in the HFNC group were significantly lower than that in the CPAP group (p < .0001 and p = .03). Serious adverse events did not significantly differ.Conclusions: HFNC had effects similar to those of CPAP regarding the failure of initial respiratory support in premature infants and was associated with reduced nasal trauma compared to CPAP. Following extubation, CPAP had fewer treatment failures than HFNC, but CPAP had a significantly increased rate of nasal trauma and pneumothorax. Further studies are needed to clarify the potential benefits of HFNC as primary respiratory support in extremely low birth weight or extremely preterm infants.

High flow nasal cannula vs non-invasive ventilation in pediatric ARDS: an RCT

Introduction: Pediatric Acute Respiratory Distress syndrome (PARDS) has been re-defined (2015) as per the final recommendations of the Pediatric Acute Lung Injury Consensus Conference. The use of high flow nasal cannula is a promising treatment but its efficacy compared with non invasive ventilation (NIV) is not known. Aims and Objectives: The current study was undertaken to study the efficacy of high flow nasal cannula compared with NIV in PARDS. Methods: This was a pilot randomized controlled trial done in the PICU of a tertiary care teaching hospital over 10 months (December 2017 – September 2018). All patients aged 1-18 years of age, who presented with or developed ARDS during their course of hospitalization, and who fulfilled the inclusion criteria, were randomized to receive HFNC and Continuous Positive Airway Pressure (NIV) as the initial respiratory support.Details were noted in a pre-designed standardized data collection form, entered into MS-EXCEL worksheet 2013 and analyzed using the Epi info software version 7.2.0.1. Results: A total of 40 patients were enrolled, 20 in each arm.Of these majority (25/40=62.5%) were boys. Majority of these patients were from rural or semi-urban areas (28/40=70.0%) and belonged to low socio-economic class (33/40= 82.5%) patients.Underlying diagnosis was sepsis in the majority (27/40=67.5%) patients.Twenty one (23/40=57.5%) patients had co-existent pneumonia.Development of hemodynamic instability approached statistical significance in being low in HFNC group compared with the CPAP group (p=0.07; OR 0.206, 95% CI 0.036-0.159).Subsequent requirement of invasive ventilation was also low in HFNC group compared with CPAP group and approached significance (p=0.09; OR 1.653, 95% CI 0.074-1.246). Total duration of respiratory support (p=0.62) was comparable in both the groups. Conclusion: HFNC is efficacious in managing PARDS. Subsequent requirement of invasive ventilation and hemodynamic deterioration was significantly low with HFNC compared with NIV (CPAP).

The Effects of Long-term CPAP on Weight Change in Patients With Comorbid OSA and Cardiovascular Disease: Data From the SAVE Trial

Although recent evidence suggests that OSA treatment may cause weight gain, the long-term effects of CPAP on weight are not well established. This study was a post hoc analysis of the Sleep Apnea Cardiovascular Endpoints (SAVE) study, a multicenter, randomized trial of CPAP plus standard care vsstandard care alone in adults with a history of cardiac or cerebrovascular events and moderate to severe OSA. Participants with weight, BMI, and neck and waist circumferences measured at baseline and during follow-up were included. Linear mixed models were used to examine sex-specific temporal differences, and a sensitivity analysis compared high CPAP adherers (≥ 4h per night) with propensity-matched control participants. A total of 2,483 adults (1,248 in the CPAP group and 1,235 in the control group) were included (mean 6.1 ± 1.5 measures of weight available). After a mean follow-up of 3.78 years, there was no difference in weight change between the CPAP and control groups, for male subjects (mean [95%CI] between-group difference, 0.07kg [-0.40 to 0.54]; P= .773) or female subjects (mean [95%CI] between-group difference, -0.14kg [-0.37 to 0.09]; P= .233). Similarly, there were no significant differences in BMI or other anthropometric measures. Although male participants who used CPAP≥ 4h per night gained slightly more weight than matched male control subjects without CPAP (mean difference, 0.38kg [95%CI, 0.04 to 0.73]; P= .031), there were no between-group differences in other anthropometric variables, nor were there any differences between female high CPAP adherers and matched control subjects. Long-term CPAP use in patients with comorbid OSA and cardiovascular disease does not result in clinically significant weight change. ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov.

Effects of Exercise Training and CPAP in Patients With Heart Failure and OSA: A Preliminary Study

Exercise and CPAP improve OSA. This study examined the effects of exercise in patients with heart failure (HF) and OSA. Patients with HF and OSA were randomized to the following study groups: control, exercise, CPAP, and exercise+ CPAP. Sixty-five participants completed the protocol. Comparing baseline vs3months, the mean apnea-hypopnea index (AHI) did not change significantly (in events per hour) in the control group, decreased moderately in the exercise group (28 ± 17 to 18 ± 12; P< .03), and decreased significantly more in the CPAP group (32 ± 25 to 8 ± 11; P< .007) and in the exercise+ CPAP group (25 ± 15 to 10 ± 16; P< .007). Peak oxygen consumption, muscle strength, and endurance improved only with exercise. Both exercise and CPAP improved subjective excessive daytime sleepiness, quality of life, and the New York Heart Association functional class. However, compared with the control group, changes in scores on the 36-item Medical Outcomes Study Short Form Survey and Minnesota Living with Heart Failure Questionnaire were only significant in the exercise groups. In patients with HF and OSA, our preliminary results showed that exercise alone attenuated OSA and improved quality of life more than CPAP. In the landscape treatment of OSA in patients with HF, this analysis is the only randomized trial showing any treatment (in this case, exercise) that improved all the studied parameters. The results highlight the important therapeutic benefits of exercise, particularly because adherence to CPAP is low.

Effect of Oxygen Therapy by Venturi Mask versus Non Invasive Ventillation on the Outcome of Patients Who Devolope Hypoxia after Open Heart Surgery

Background: Cardiothoracic surgery is a common cause of acute respiratory failure and is associated with increased morbidity and mortality. We aimed to compare the outcomes of open heart surgery patients treated using oxygen delivery devices with patients who receive NIV as a first-line therapy for hypoxemic respiratory failure. Materials and Methods: 40 patients who developed acute hypoxemic respiratory failure after open heart surgery and admitted to cardiothoracic ICU 20 patients received NIV and 20 patient received oxygen by venture mask. For all patients the following measurements were performed before and after CPAP AND Venture use: CBC, blood urea, serum creatinine body temperature, chest X-ray, Arterial blood gases (arterial pH, sodium bicarbonate, pcO2, SpO2 and PaO2-to-FiO2 ratio). Results: Mean PO2 and SO2 have increased after using of both venture and Cpap, increase in both PCO2 and HCO3 levels after using Venturi mask, CPAP mask was superior to venturi mask in avoiding the need of intubation, decreasing The ICU stay median length and also median length of hospitalization, all were lower in CPAP group than venture group. Also the mortality rate was lower in CPAP group than the venturi group. Conclusion: Using CPAP mask in severe AHRF following open heart surgery can avoid intubation, decreases the levels of tachypnea and arterial hypoxemia, decreases ICU stay, the length of hospitalization and also decreases the mortality rate compared with patients receiving high-concentration oxygen therapy with venture mask.

CPAP by helmet for treatment of acute respiratory failure after pediatric liver transplantation.

ARF after pediatric liver transplantation accounts for high rate of morbidity and mortality associated with this procedure. The role of CPAP in postoperative period is still unknown. The aim of the study was to describe current practice and risk factors associated with the application of helmet CPAP. In this retrospective observational cohort study, 119 recipients were divided into two groups based on indication to CPAP after extubation. Perioperative variables were studied, and determinants of CPAP application were analyzed in a multivariate logistic model. Sixty patients (60/114) developed ARF and were included in the CPAP group. No differences were found between the two groups for primary disease, graft type, and blood product transfused. At multivariate analysis, weight <11kg (OR=2.9; 95% CI=1.1-7.3; P=.026), PaO2 /FiO2 <380 before extubation (OR=5.4; 95% CI=2.1-13.6; P<.001), need of vasopressors (OR=2.6; 95% CI=1.1-6.4; P=.038), and positive fluid balance >148mL/kg (OR=4.0; 95% CI=1.6-10.1; P=.004) were the main determinants of CPAP application. In the CPAP group, five patients (8.4%) needed reintubation. Pediatric liver recipients with lower weight, higher need of inotropes/vasopressors, higher positive fluid balance after surgery, and lower PaO2 /FiO2 before extubation were at higher odds of developing ARF needing CPAP application.

Does continuous positive airway pressure treatment affect autonomic nervous system in patients with severe obstructive sleep apnea?

ObjectiveThis study is aimed at evaluating whether Continuous Positive Airway Pressure treatment (CPAP) may affect autonomic nervous system (ANS) in male patients with severe obstructive sleep apnea (OSAS). MethodsWe compared autonomic symptoms of de novo severe OSAS patients, OSAS patients on chronic CPAP treatment and healthy controls, using the Scales for Outcome in Parkinson disease-Autonomic (SCOPA-AUT) questionnaire. All groups underwent cardiovascular function tests including head-up tilt test (HUTT), Valsalva maneuver, deep breathing, hand grip and cold face tests. Statistical significance was set at p < 0.05. ResultsTwelve de novo severe OSAS patients, 17 male OSAS on CPAP and 14 controls were studied. The mean SCOPA-AUT total score was significantly higher in de novo OSAS patients compared with controls. Regarding the distinct domains, both de novo OSAS and CPAP group had abnormalities in respect of controls in urinary sphere. In supine rest condition the baseline values of systolic blood pressure were significantly increased in untreated OSAS patients compared with controls, whereas the basal values of diastolic blood pressure were significantly higher in CPAP patients with respect to controls. After ten min of HUTT, diastolic blood pressure changes were significantly higher in controls compared to both OSAS groups. Untreated OSAS patients showed significant different responses at deep breathing compared to controls. Both OSAS groups had a significant reduction of reflex bradycardia at cold face test. ConclusionsOur study shows that both treated and untreated OSAS patients complain of subjective autonomic symptoms like other sleep disorders reinforcing the close relationship between sleep and autonomic activity. Furthermore, cardiovascular reflexes indicate a tendency to hypertension and a reduced sensitivity to stimuli during wakefulness even in OSA patients on CPAP treatment, suggesting potentially permanent autonomic function deficits.

Effect of Noninvasive Positive Pressure Ventilation During Large Volume Thoracentesis on Pleural Manometry

SESSION TITLE: Pleural Disease SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: It has been observed that the symptoms of chest pain during large volume thoracentesis and the possibility of re-expansion pulmonary edema occur due to a large drop in the intrapleural pressure during large volume thoracentesis. Due to these factors thoracenteses are frequently terminated prior to the removal of maximal volumes. Consequently, patients may have incomplete drainage or need for multiple procedures. This is an initial pilot study to determine whether the application of non-invasive positive pressure ventilation at a relatively low pressure (CPAP 5mm H2O) during large volume thoracentesis could prevent excessive drop in pleural pressure (pPl). METHODS: A prospective, randomized controlled, non-blinded study of 49 consecutive adults who underwent thoracentesis was performed. We compared the changes in opening and closing pPl using a pleural manometry in patients assigned to continuous positive airway pressure of 5 mmH2O (treatment group) and patients without CPAP (control group). The Mann Whitney U test was used to analyze the results. An independent t test was used to compare the average volume drained between the two groups. RESULTS: Patients treated with CPAP 5 mmH2O had a significantly smaller drop in pleural pressures as compared to patients without CPAP (median of -11cmH2O vs -17.5 cmH2O respectively, p = 0.006). The average volume drained was not statistically significant in the CPAP group (1380 ml) vs the non-CPAP group (1371ml) with a p value 0.953. CONCLUSIONS: Our study demonstrates that the application of CPAP at 5 mmH2O is an effective measure to minimize drops in intrapleural pressures during large volume thoracentesis. We did not collect data on patients’ adverse events post procedure. Further studies at potentially higher CPAP pressure, side effects recording and follow-up imaging are needed to evaluate if preventing the drop in Ppl with CPAP will directly correlate with symptoms and adverse effects. CLINICAL IMPLICATIONS: The application of CPAP during large volume thoracentesis is an effective measure to minimize drops in intrapleural pressures, potentially decreasing adverse effects during this procedure. DISCLOSURE: The following authors have nothing to disclose: Karla Cruz Morel, Jonathan Kass, Ziad Boujaoude, Rohan Arya, Diana Kolman, Wissam Abouzgheib No Product/Research Disclosure Information

Correction of intermittent hypoxia reduces inflammation in obese subjects with obstructive sleep apnea.

In obese subjects with obstructive sleep apnea (OSA), chronic intermittent hypoxia (CIH) may be linked to systemic and adipose tissue inflammation. We obtained abdominal subcutaneous adipose tissue biopsies from OSA and non-OSA obese (BMI > 35) subjects at baseline and after 24 weeks (T1) of weight-loss intervention plus continuous positive airway pressure (c-PAP) or weight-loss intervention alone, respectively. OSA subjects were grouped according to good (therapeutic) or poor (subtherapeutic) adherence to c-PAP. At baseline, anthropometric and metabolic parameters, serum cytokines, and adipose tissue mRNA levels of obesity-associated chemokines and inflammatory markers were not different in OSA and non-OSA subjects. At T1, body weight was significantly reduced in all groups. Serum concentrations of IL-2, IL-4, IL-6, MCP-1, PDGFβ, and VEGFα were reduced by therapeutic c-PAP in OSA subjects and remained unaltered in non-OSA and subtherapeutic c-PAP groups. Similarly, adipose tissue mRNA levels of macrophage-specific (CD68, CD36) and ER stress (ATF4, CHOP, ERO-1) gene markers, as well as of IL-6, PDGFβ, and VEGFα, were decreased only in the therapeutic c-PAP group. CIH does not represent an additional factor increasing systemic and adipose tissue inflammation in morbid obesity. However, in subjects with OSA, an effective c-PAP therapy improves systemic and obesity-associated inflammatory markers. Ministero dell'Università e della Ricerca and Progetti di Rilevante Interesse Nazionale.

A randomized pilot study comparing the role of PEEP, O2 flow, and high-flow air for weaning of ventilatory support in very low birth weight infants

There is a lack of evidence to guide step-wise weaning of positive pressure respiratory support for premature infants. This study sought to compare the efficacy of three weaning protocols we designed to facilitate weaning of very low birth weight (VLBW, less than 1500g) preterm infants from nasal continuous positive airway pressure (NCPAP) support. This was a prospective, randomized, controlled trial of VLBW preterm infants who received positive pressure ventilatory support in our neonatal intensive care unit (NICU) from April 2008 through March 2009. When these infants were weaned to CPAP as their last step of respiratory support, they would be randomly assigned to one of the following three groups as their further weaning methods (M): (M1) CPAP group, (M2) O2 flow group, and (M3) air flow group. The time period they needed to wean off any kind of respiratory support, as well as the likelihood of developing relevant prematurity related morbidities, were compared among patients using different weaning modalities. 181 patients were enrolled in the study. Their gestational age (GA) and birth weight (BW) were 29.1±2.5, 28.7±2.4, 28.7±2.4 (mean±SD) weeks and 1142±232, 1099±234, 1083±219g, in M1, M2 and M3, respectively. The time (period) needed to wean off support was 16.0±10.0 days (M1), 11.6±6.4 days (M2), and 15.0±8.9 days (M3), respectively (p=.033). Incidence of retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) were both significantly higher in the O2 flow group (p=.048). Although using low oxygen flow significantly shortens CPAP weaning time, it may increase risks of BPD and ROP, both known to be related to oxygen toxicity. Unless the infant has BPD and is O2-dependent, clinicians should consider using air flow or just splinting with no support at all when weaning NCPAP.

PP.18.11] INFLUENCE OF CPAP THERAPY ON ENDOTHELIAL FUNCTION IN PATIENTS WITH TYPE 2 DIABETES ACCORDING TO FLOW-MEDIATED VASODILATION

Objective: to assess the dynamics of parameters of endothelial function in patients with type 2 diabetes, suffering from medium to severe obstructive sleep apnea (OSA). Design and method: 42 subjects with diabetes and moderate to severe OSA were examined. During 12 weeks 22 patients (group 1 CPAP) in addition to antihypertensive treatment (AHT) received CPAP-therapy with «SOMNObalance» (Weinmann, Germany). Control group (C) included 20 patients without additional treatment by CPAP. The subjects were matched by age, sex, height, office blood pressure values. All enrolled patients had arterial hypertension 1–2 degrees. Assessment of respiratory disorders during sleep was carried out using cardio-respiratory monitoring device SOMNOcheck2 (Weinmann, Germany). Endothelial function was evaluated by the ultrasonic device MyLab 90 (Esaote, Italy). Index of reactivity (IR), flow-mediated dilation (FMD), the diameter of the common carotid artery (DCCA) and the intima-media thickness (IMT) on the right and left were assessed. Results: Initially there were no significant differences between groups for all parameters of comparison, reflecting endothelial function. In CPAP group baseline values of IR were1,3 ± 0,3, FMD - 8,4 ± 4,9%, DCCA - 7 ± 1,1 mm, IMT - 1,1 ± 0,2 mm. During the CPAP-therapy IR increased to 1,5 ± 0,3 (15,7%; p < 0,05), FMD to 12,2 ± 3,0% (45,2%; p < 0,05). DCCA and IMT values after 12 weeks decreased to 6,95 ± 1,1 mm (ns) and 1,0 ± 0,1 mm, respectively (p < 0,05). In patients of control group the IR at baseline was 1,2 (1,1; 1,4), FMD - 7,5 (5; 9,52)%, DCCA- 6,2 (5,45; 6,5) mm, IMT - 1,0 ± 0,1 mm. In the control group FMD increased to 8,9 ± 5,3% (15,5%; p < 0,05). IR values, IMT and DCCA were not significantly changed in control group, and amounted to 1,5 ± 0,4; 5,7 ± 1,0 mm, and 1,0 ± 0,1 m/s, respectively. Conclusions: the application of CPAP in patients with diabetes and apnea syndrome contributes to a significant improvement in endothelial function according to flow-mediated dilation.

Efficacy of continuous positive airway pressure and incentive spirometry on respiratory functions during the postoperative period following supratentorial craniotomy: A prospective randomized controlled study

Study objectiveVolume controlled ventilation with low PEEP is used in neuro-anesthesia to provide constant PaCO2 levels and prevent raised intracranial pressure. Therefore, neurosurgery patients prone to atelectasis formation, however, we could not find any study that evaluates prevention of postoperative pulmonary complications in neurosurgery. DesignA prospective, randomized controlled study. SettingIntensive care unit in a university hospital in Istanbul. PatientsSeventy-nine ASAI-II patients aged between 18 and 70years scheduled for elective supratentorial craniotomy were included in the study. InterventionsPatients randomized into 3 groups after surgery. The Group IS (n=20) was treated with incentive spirometry 5 times in 1min and 5min per hour, the Group CPAP (n=20) with continuous positive airway pressure 10 cmH2O pressure and 0.4 FiO2 via an oronasal mask 5min per hour, and the Group Control (n=20) 4L·min−1O2 via mask; all during the first 6h postoperatively. Respiratory functions tests and arterial blood gases analysis were performed before the induction of anesthesia (Baseline), 30min, 6h, 24h postoperatively. Main resultsThe IS and CPAP applications have similar effects with respect to FVC values. The postoperative 30min FEV1 values were statistically significantly reduced compared to the Baseline in all groups (p<0.0001). FEV1 values were statistically significantly increased at the postoperative 24h compared to the postoperative 30min in the Groups IS and CPAP (p<0.0001). This increase, however, was not observed in the Group Control, and the postoperative 24h FEV1 values were statistically significantly lower in the Group Control compared to the Group IS (p=0.015). ConclusionAlthough this study is underpowered to detect differences in FEV1 values, the postoperative 24h FEV1 values were significantly higher in the IS group than the Control group and this difference was not observed between the CPAP and Control groups. It might be evaluate a favorable effect of IS in neurosurgery patients. But larger studies are needed to make a certain conclusion.

Is high-flow nasal cannula noninferior to nasal CPAP for the initial management of preterm infants?

Commentary on: Roberts CT, Owen LS, Manley BJ, Frøisland DH, Donath SM, Dalziel KM, Pritchard MA, Cartwright DW, Collins CL, Malhotra A, Davis PG, for the HIPSTER Trial Investigators. Nasal high-flow therapy for primary respiratory support in preterm infants. N Engl J Med 2016; 375: 1142–51. PMID 27653564. The study question builds on the group's earlier work, which demonstrated HFNC was noninferior to nCPAP as postextubation support 1. Noninferiority trials are designed to show whether a new treatment is ‘not unacceptably less efficacious’ than the standard of care 2. A new treatment that is nearly as effective may be acceptable to providers and patients if it is less invasive, less costly or more convenient. 3 Of note, the authors defined a 20% margin for noninferiority in their earlier study 1, and a 10% difference in the rate of treatment failure between HFNC and nCPAP here may be too conservative. In contrast to studies of HFNC as postextubation support 1, 4, Roberts et al. found HFNC as primary support to be not only inferior to nCPAP, but the difference was obvious prior to full recruitment, and was significant in both the intention-to-treat and per-protocol analyses. The authors posit the higher rate of treatment failure in the HFNC group ‘may reflect its reduced effectiveness in infants with surfactant-deficient lungs’. Were this the case, the HFNC group should have had higher need for subsequent surfactant therapy than the CPAP group, but the rates of surfactant administration were equivalent. Treatment failure (in either group) may have occurred after the window during which surfactant is considered to be most efficacious (<24–48 hours of life) and thus was not used. Defining ‘treatment failure’ by two objective and three somewhat subjective criteria complicates the interpretation of the results. Apnoea in particular is subjective in terms of nursing documentation, and the inability to blind caregivers to mode of respiratory support may have impacted the perceived frequency and severity of apneic episodes. In practice, failure of noninvasive respiratory support typically means need for intubation and mechanical ventilation, but intubation rates during the treatment period were not significantly different between the HFNC and nCPAP groups. Approximately 30 infants on HFNC had treatment failure but stabilised on nCPAP; 40 infants failed HFNC and ultimately required intubation and surfactant. While this confirms something about nCPAP therapy was superior to HFNC, it seems unlikely to indicate such a substantial treatment effect that continued enrolment in the study would have been unsafe or unethical. Overall rates of intubation and pneumothorax were the same, length of stay was unchanged, and the rate of nasal breakdown was higher in the nCPAP group. It would be helpful to know if there was a clinically important increase in the frequency of pneumothorax and nasal breakdown specifically in the crossover group from HFNC to nCPAP. Because an increased cumulative oxygen exposure in the HFNC group is plausible, reporting the average FiO2 requirement for both groups also would be useful. Based on these findings, the standard use of HFNC as primary respiratory support in preterm infants who would otherwise receive CPAP cannot be recommended. However, the important complications of pneumothorax and intubation were ultimately not different between groups, nor did length of stay or cost of care differ significantly. This suggests HFNC may be an option for some infants without fear of significant adverse events. https://ebneo.org/2017/04/is-high-flow-nasal-cannula-noninferior-to-nasal-cpap-for-the-initial-management-of-preterm-infants/ The authors of this commentary have no conflict of interests to disclose. The authors of this commentary have no funding to disclose.

Preventing extubation failure in preterm infants: nasal CPAP remains the standard of care

Commentary on: Manley BJ, Owen LS, Doyle LW, Andersen CC, Cartwright DW, Pritchard MA, Donath SM, Davis PG. High-Flow Nasal Cannulae in Very Preterm Infants after Extubation. N Engl J Med 2013; 369:1425-33. PMID 24106935. Improving rates of extubation failure in very preterm infants remains an important and elusive goal. Postextubation CPAP prevents extubation failure and is the standard of care for preterm infants 1, 2. Alternative methods of delivering positive distending pressure to preterm infants, including high-flow nasal cannula (HFNC), are widely used and increasingly popular. The stated advantages of HFNC are ease of use, increased comfort and less nasal trauma. Unfortunately, retrospective analysis suggests potential harm from HFNC use in VLBW infants, highlighting the urgent need for prospective randomised controlled trials to guide clinical practice 3. Manley and colleagues determined whether HFNC performed similarly to nasal CPAP for preventing extubation failure in very preterm infants (<32 weeks) 4. The trial revealed that HFNC was noninferior to CPAP in preventing extubation failure. Importantly, noninferiority was defined as 20 percentage points above the extubation failure rate for CPAP. Treatment failure occurred in 34.2% of the HFNC group and 25.8% in the CPAP group (risk difference, 8.4 percentage points, 95% confidence interval, −1.9 to 18.7). While this difference did not reach statistical significance, the upper limit of the 95% confidence interval bordered on the margin of noninferiority. A potential criticism of this otherwise well done trial has been using up to a 20% difference to define ‘noninferior’ 5. Additionally, the difference in failure rate was exaggerated in infants <26 weeks gestational age. Specifically, 61.3% of infants <26 weeks failed CPAP, while 81.3% of infants failed HFNC. Although the study was not powered to detect differences in this small subgroup of patients (63 infants), the authors urge caution when considering the use of HFNC in these patients. Furthermore, approximately half of the patients failing HFNC were salvaged with CPAP, thus resulting in a lower (17.8%) re-intubation rate in patients randomised to HFNC compared to those randomised to CPAP (25.2%). Lastly, nasal trauma was infrequent and rates did not differ by group. Where do these data leave us? Does HFNC perform similarly to CPAP for preventing extubation failure in very preterm infants (<32 weeks GA)? Statistically, yes. However, the authors acknowledge that they ‘chose a generous noninferiority margin’ 6. Ultimately, does HFNC perform well enough compared to CPAP to justify its use to prevent extubation failure? As the authors pointed out, these data clearly argue against the routine use of HFNC following extubation for infants <26 weeks. Furthermore, these data provide no compelling argument that HFNC should be considered as equivalent to nasal CPAP as the current standard of care for preventing extubation failure. However, these data would suggest that HFNC is safe and well tolerated and warrants further study in the NICU. https://ebneo.org/2015/04/delivering-non-invasive-positive-pressure-to-prevent-extubation-failure-in-preterm-infants-nasal-cpap-remains-the-standard-of-care/ None. CW: R01HL132941. LS: T32007186-32.

Significant improvement of olfactory performance in sleep apnea patients after three months of nasal CPAP therapy - Observational study and randomized trial.

ObjectivesThe olfactory function highly impacts quality of life (QoL). Continuous positive airway pressure is an effective treatment for obstructive sleep apnea (OSA) and is often applied by nasal masks (nCPAP). The influence of nCPAP on the olfactory performance of OSA patients is unknown. The aim of this study was to assess the sense of smell before initiation of nCPAP and after three months treatment, in moderate and severe OSA patients.MethodsThe sense of smell was assessed in 35 patients suffering from daytime sleepiness and moderate to severe OSA (apnea/hypopnea index ≥ 15/h), with the aid of a validated test battery (Sniffin’ Sticks) before initiation of nCPAP therapy and after three months of treatment. Additionally, adherent subjects were included in a double-blind randomized three weeks CPAP-withdrawal trial (sub-therapeutic CPAP pressure).ResultsTwenty five of the 35 patients used the nCPAP therapy for more than four hours per night, and for more than 70% of nights (adherent group). The olfactory performance of these patients improved significantly (p = 0.007) after three months of nCPAP therapy. When considering the entire group of patients, olfaction also improved significantly (p = 0.001). In the randomized phase the sense of smell of six patients deteriorated under sub-therapeutic CPAP pressure (p = 0.046) whereas five patients in the maintenance CPAP group showed no significant difference (p = 0.501).ConclusionsOlfactory performance improved significantly after three months of nCPAP therapy in patients suffering from moderate and severe OSA. It seems that this effect of nCPAP is reversible under sub-therapeutic CPAP pressure.Trial registrationISRCTN11128866

OP.8B.03] EFFECT OF CPAP THERAPY ON CENTRAL PRESSURE AND RIGIDITY IN PATIENTS WITH TYPE 2 DIABETES

Objective: To evaluate the effect of CPAP therapy on central (aortic) pressure and vascular stiffness in patients with type 2 diabetes mellitus (DM), suffering from moderate to severe obstructive sleep apnea (OSA). Design and method: The study involved 42 people with diabetes combined with hypertension 1–2 degrees and of moderate-to-severe OSA. 22 patients (group 1 CPAP) in addition to antihypertensive treatment (AHT) received a 12-week CPAP-therapy by device «Somnobalance e» (Weinmann, Germany). The 2nd (control - C) group consisted of 20 patients with diabetes who were on drug therapy without additional treatment by CPAP. The subjects were matched by age, sex, height, office blood pressure values. Assessment of respiratory disorders during sleep was carried out using cardiorespiratory monitoring SOMNOcheck2 (Weinmann, Germany). Biochemical parameters were determined by the Olympus AU 400 instrument (Olympus Corporation, Japan). In addition, the values of aortic pressure (SBPao, DBPao) during the night were evaluated by the technology Vasotens (Peter Telegin, Russia). Results: Capillary blood glucose levels in patients in group 1 were 8,8 ± 1,9 mmol/l, HbA1C - 8,1 ± 0,8%; in subjects in group 2 - 8,2 ± 1,6 mmol/l and 0,9 ± 7,9%, respectively (p > 0,05). Fasting glycemia in CPAP group after 12 weeks decreased by 12.5% (p < 0,01), HbA1C - 4% (p < 0,05); in patients of control group, respectively, 4,9% and 1,3% (p > 0,05). According to the daily monitoring in group 1 the initial values of SBPao and BPao were 124,5 (119,5; 135,5) and 78 ± 5,9 mmHg, in group 2 - 123,1 ± 9,7 mmHg, and 78,9 ± 9,2 mmHg (ND). Against the background of the 12-week treatment in CPAP group the values of SBPao decreased by 9,4%, (p < 0,01), DBPao - by 15,3% (p < 0,01). In the control group dynamic of SBPao was 5,1% (p < 0,05), DBPao - 7,3% (p < 0,01). Conclusions: The use of CPAP in patients with type 2 diabetes mellitus combined with hypertension and apnea contributes to a more pronounced decline in the central (aortic) pressure and the effective control of parameters of carbohydrate metabolism.

OS 12-02 SLEEP APNEA CARDIOVASCULAR ENDPOINTS (SAVE) STUDY

Abstract There is uncertainty over whether treatment of obstructive sleep apnea (OSA) can prevent serious cardiovascular (CV) events. SAVE (NCT00738179; ACTRN12608000409370) was designed to determine whether treatment of OSA with CPAP reduces the risk of serious CV events in patients with established CV disease. Participants were centrally randomised to CPAP treatment or usual care between 2008 and 2013,with follow-up completed late 2015 and the results will be announced in August 2016. The primary endpoint is a composite of CV death, myocardial infarction, stroke, hospitalisation for heart failure, and hospitalisation for either an acute ischemic cardiac event or transient ischemic event (TIA). Sample size was set at 2500 to provide 90% power (alpha 0.05) to detect a 25% relative risk reduction in the primary endpoint in the CPAP group compared with the usual care group. This international, prospective, open, randomised controlled clinical trial of CPAP for the prevention of major and minor CV events recruited 2717 participants with co-existing CV disease and moderate to severe OSA from clinics in Australia and New Zealand, China, India, Spain, and the USA. The main results will be presented at the conference. SAVE will determine whether treatment of OSA in patiens with CV disease can prevent secondary major CV events, the results of which will have significant impact on clinical practice.

PS 17-18 DYNAMICS OF PARAMETERS OF ENDOTHELIAL FUNCTION IN PATIENTS WITH TYPE 2 DIABETES ACCORDING TO FLOW-MEDIATED DILATION DURING THE CPAP-THERAPY

Objective: To evaluate the effect of CPAP therapy on endothelial function in patients with type 2 diabetes mellitus (DM), combined with moderate to severe obstructive sleep apnea (OSA). Design and method: The study involved 42 people with diabetes combined with hypertension of 1–2 degrees and moderate-to-severe OSAS. 22 patients (group 1 - CPAP) in addition to antihypertensive treatment received a 12-week CPAP-therapy by device «Somnobalance e» (Weinmann, Germany). The 2nd (control - C) group consisted of 20 patients with diabetes who were on drug therapy without treatment by CPAP. The subjects were matched by age, sex, height, office BP values. Assessment of respiratory disorders during sleep was performed by cardiorespiratory monitoring SOMNOcheck2 (Weinmann, Germany). Endothelial function was evaluated by flow-mediated vasodilation using the MyLab 90 ultrasound machine (Esaote, Italy). The index of reactivity (IR), and flow-mediated dilation (FMD) have been determined. We evaluated the diameter of the common carotid artery (DCCA) and the intima-media thickness (IMT). Results: Before treatment, there were no significant differences between the comparison groups in all parameters, reflecting endothelial function. In CPAP group the initial values of IR were 1,3 ± 0,3, FMD - 8,4 ± 4,9%, DCCA - 7 ± 1,1 mm, IMT - 1,1 ± 0,2 mm. During the treatment an increase of IR to 1,5 ± 0,3 (15,7%; p < 0,05) and FMD to 12,2 ± 3,0% (45,2%; p < 0,05) has been revealed. DCCA and IMT values after 12 weeks decreased to 6,95 ± 1,1 mm (p > 0,05) and 1,0 ± 0,1 mm, respectively (p < 0,05). In group C baseline values of IR were 1,2 (1,1; 1,4), FMD – 7,5 (5; 9,52)%, DOS – 6,2 (5,45; 6,5) mm, IMT - 1,0 ± 0,1 mm. In group C the FMD parameter increased to 8,9 ± 5,3% (15,5%; p < 0,05), IR values, DCCA and IMT were not changed and amounted to 1,5 ± 0,4; 5,7 ± 1,0 mm and 1,0 ± 0,1 m/s, respectively. Conclusions: The application of CPAP contributes to a significant improvement in endothelial function according to flow-mediated dilation.

Effect of Heated Humidification on CPAP Therapy Adherence in Subjects With Obstructive Sleep Apnea With Nasopharyngeal Symptoms.

The addition of heated humidification to CPAP has been shown to improve nasal adverse effects in subjects with obstructive sleep apnea (OSA). However, current data regarding improvement in CPAP adherence is conflicting. Furthermore, there are no data from a tropical climate area with a high humidity level. In this prospective randomized crossover study conducted in Thailand, subjects with moderate to severe OSA with nasopharyngeal symptoms post-split-night study were enrolled in the study. Subjects were randomly assigned to receive CPAP with or without heated humidification for 4 weeks and then crossed over. Information on CPAP adherence, quality of life assessed by the Functional Outcomes of Sleep Questionnaire, nasopharyngeal symptoms assessed by a modified XERO questionnaire, and bedroom ambient humidity and temperature data were obtained. Data were collected on 20 subjects with OSA during the period of January to December 2014. Although the addition of heated humidification appeared to improve average hours of use for all days when compared with conventional CPAP, the difference was not statistically significant (CPAP with heated humidification = 4.6 ± 1.7 h/night; conventional CPAP = 4.0 ± 1.7 h/night, P = .1). However, the addition of heated humidification improved CPAP adherence on the days of use (5.5 ± 1.5 h/night) compared with conventional CPAP (5.2 ± 1.4 h/night), P = .033. Quality of life was also improved according to the Functional Outcomes of Sleep Questionnaire score (median 17.6 [interquartile range 3.5]) in the heated humidification group compared with conventional CPAP group (median 17.6 [interquartile range 4.5]), P = .046. Significant reduction in the dry throat/sore throat symptom was noted only when CPAP with heated humidification was used. Even in a tropical climate area, CPAP adherence and quality of life appeared to improve when heated humidification was employed in subjects with moderate to severe OSA with nasopharyngeal symptoms post-split-night polysomnography. The improvement may be related to a reduction in the dry throat/sore throat symptom.