Automatic Continuous Positive Airway Pressure Research Articles

An Alternative In-Home Protocol to Diagnose and Treat Obstructive Sleep Apnea

Abstract Objective Obstructive sleep apnea (OSA) is a major public health problem of pandemic proportions. In-laboratory OSA diagnosis and continuous positive airway pressure (CPAP) titration are insufficient, considering the number of patients affected. Finding alternative ways to diagnose and treat OSA is mandatory, especially in this era of the coronavirus disease 2019 (COVID-19) pandemic. The present study aims to describe an alternative in-home protocol to diagnose and treat OSA. Materials and Methods We enrolled consecutive patients aged ≥ 18 years with moderate/severe OSA, who underwent in-home type-III polysomnography and home-based titration with automatic CPAP, coupled with an oximetry sensor for 3 consecutive nights. Patients were remotely monitored for 90 days to evaluate CPAP compliance and the use of an engagement tool was encouraged. Results We included 86 participants. The median time until the diagnosis was of one day. The mean time from the baseline visit until the acquisition and initiation of the CPAP therapy was of 33 (range: 17 to 52) days. Telemonitoring ensured good compliance in the first 30 (79.2%), 60 (76.3%) and 90 (74.3%) days, with an average daily use of 6.2 ± 1.4 h, 6.0 ± 1.4 h, and 6.0 ± 1.3 h respectively. About 1/3 of the patients used the engagement tool, and CPAP compliance was significantly higher among these patients compared with those who did not used the tool: 89.9% versus 73.5% (p < 0.002), 87.9% versus 70% (p < 0.003), and 86.6% versus 67.6% (p < 0.001) at 30, 60, and 90 days respectively. Conclusion We demonstrated that an alternative in-home protocol to diagnose and treat OSA is effective, ensuring good CPAP compliance after 90 days. Telemonitoring and engagement tools could be strategies to improve CPAP compliance.

Early Diagnosis of Respiratory Disease in Light of COVID-19 Infection and Use of Oxygen Concentrators and CPAP Devices for the Treatment of Respiratory Failure

The need for early diagnosis of respiratory diseases, especially in the context of the COVID-19 coronavirus infection pandemic, by means of pulse oximetry screening and monitoring has been substantiated. The expediency of using portable pulse oximeters by therapists and general practitioners is shown. The main respiratory diseases accompanied by respiratory failure, which can be promptly detected by pulse oximetry, are chronic obstructive pulmonary disease and obstructive sleep apnea-hypopnea syndrome. Early detection of these diseases is an urgent task due to the low severity of symptoms of these diseases in the early stages and, as a consequence, the prevalence of late diagnosis. Pulse oximetry to detect coronavirus infection COVID-19 deserves special attention, since this infection is also accompanied by respiratory failure. The use of oxygen concentrators and CPAP devices for the treatment of respiratory failure has been argued. The effectiveness of the appointment of long-term oxygen therapy using oxygen concentrators in patients with chronic obstructive pulmonary disease, CPAP therapy using automatic CPAP devices in patients with obstructive sleep apnea-hypopnea syndrome with mandatory pulse oximetry monitoring has been confirmed. A retrospective analysis of 120 cases of treatment of moderate and severe COVID-19 infection complicated by the development of pneumonia was carried out. The efficiency of using oxygen concentrators to supply patients with oxygen at a flow rate of up to 5 l / min has been proven. It was found that no more than 10% of patients needed an oxygen flow at a rate of more than 5 l/min. At the same time, the possibility of using CPAP devices for non-invasive ventilation of the lungs using full-face masks has been shown. The expediency of using oxygen concentrators and CPAP devices for the rehabilitation of patients who have undergone COVID-19 was noted.

Treatment of obstructive sleep apnea with a simple CPAP device

PurposeCPAP is the “gold standard” treatment for obstructive sleep apnea (OSA). Current CPAP models have developed additional functions including automatic CPAP and pressure relief. However, CPAP adherence has not improved over the last three decades. Many patients in low-income countries cannot afford these CPAP devices. A novel simple CPAP device with a fixed pressure without pressure controller was developed.MethodsManual CPAP pressure titration was performed in 127 patients with OSA. Six patients with a titration pressure higher than 11 cmH2O and 14 patients who could not tolerate CPAP were excluded, leaving 107 participating in the following 2 studies. In study one, 54 of 107 patients were treated by both conventional fixed CPAP and simple CPAP in random order. In the second study, another 53 patients were treated by both autoCPAP in automatic function and simple CPAP in random order. Simple CPAP was fixed at 10 cmH2O, 8 cmH2O, and 6 cmH2O for patients whose titration pressure was between 9–10, 7–8, and ≤ 6 cmH2O, respectively. Conventional fixed CPAP device was set exactly the same as manual titration pressure.ResultsAll patients whose manual titration pressure ≤ 10 cmH2O were effectively treated by simple CPAP (AHI 40.7 ± 2.3 events/h before vs 2.5 ± 0.3 events/h after, p < 0.001). Patients expressed similar preferences for simple CPAP, autoCPAP, and conventional fixed CPAP (p > 0.05).ConclusionsWe conclude that a novel simple CPAP is an alternative treatment for most patients with OSA, which may widen access to CPAP therapy in the developing countries because of its low cost.

Polysomnographic evaluation of obstructive sleep apnea treatment with fixed pressure CPAP determined by formula.

PurposeThe use of continuous positive airway pressure (CPAP) is one of the therapeutic modalities for obstructive sleep apnea (OSA). Manual titration polysomnography and the 90th or 95th percentiles of pressure titrated by automatic CPAP (APAP) are the current standard for determining fixed pressure. Pressures programmed at an arbitrary fixed value, or at preset values based on body mass index (BMI) or by predictive formulas, are presented as alternative forms. This study aimed to evaluate the residual apnea–hypopnea index (r-AHI) in polysomnography with CPAP therapy using pressure determined by formula and assess its feasibility to start treatment.MethodsPatients referred for CPAP therapy were followed up in three outpatient assessments and underwent polysomnography study with pressure CPAP obtained by formula.ResultsThe study sample consisted of 80 patients, 41 women; age 58.6 ± 11.3 years, BMI 34.1 ± 7.5 kg/m2 and cervical circumference 42.0 ± 4.2 cm. Most patients (74%) had severe OSA and Epworth sleepiness scale (ESS) of 12.0 ± 5.7 points. The calculated average pressure was 7.8 ± 2.1 cmH2O. Polysomnography studies showed an r-AHI of 6.1 ± 5.2 events/h and reduction of 84% from baseline AHI. The r-AHI in the REM-supine was 8.4 ± 9.9 events/h. At 30- and 120-day follow-up assessment, adherence to CPAP was 78% and 75% and the ESS score was 6.9 and 6.1 points, respectively.ConclusionResults suggest that a formula provides an effective initial pressure in the majority of patients (73%). This simplified approach appears to be a viable alternative, with reductions in waiting lists and time from diagnosis to initiation of therapy.

A case of sleep-disordered breathing where adaptive servo-ventilation was applied for old myocardial infarction and chronic heart failure that were found due to aggravated hypopnea and Cheyne-Stokes respiration during an automatic continuous positive airway pressure regimen

A case of sleep-disordered breathing where adaptive servo-ventilation was applied for old myocardial infarction and chronic heart failure that were found due to aggravated hypopnea and Cheyne-Stokes respiration during an automatic continuous positive airway pressure regimen

Effects of Pressure Control Device (SensAwake™) on Obstructive Sleep Apnea (OSA) Patients Who Remove the Mask for Unknown Reasons during Automatic Continuous Positive Airway Pressure (Auto-CPAP) Therapy: A Prospective Randomized Crossover Trial.

Backgroundand Objectives: Obstructive sleep apnea (OSA) patients may remove their mask unconsciously during automatic continuous positive airway pressure (Auto-CPAP) therapy and therefore cannot receive good treatment. The discomfort from the airflow of Auto-CPAP may be one reason for interrupted sleep. Sens Awake (SA) can detect the arousal and lower the pressure to prevent patients from fully awakening from sleep. Materials and Methods: To evaluate the effect of SA, we designed a prospective, randomized, crossover trial comparing Auto-CPAP with and without SA on Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Nasal Obstruction Symptom Evaluation (NOSE) Scale and recorded data from the auto-CPAP machine. Results: In the 25 patients who completed the study, the gender, age, body mass index, neck circumference, polysomnography data, and previous CPAP use were not significantly different between the two arms. The average and 90th percentile pressures were significantly lower during SA on (SA on vs. off: 6.9 ± 2.7 vs. 7.3 ± 2.6 [p = 0.032] and 8.6 ± 3.0 vs. 9.2 ± 2.9 [p = 0.002], respectively). The time used, days used, compliance, average and 90th percentile leaks, and the residual Apnea-Hypopnea Index (AHI) were not significantly changed between the SA on-and-off. Based on the subjective evaluation, PSQI, ESS, and NOSE were not significantly different between the SA on-and-off; however, based on additional analyses which were compared with baseline data, the ESS was significantly lower when the SA was on (SA on vs. baseline: 11.1 ± 6.1 vs. 13.2 ± 6.0 [p = 0.023]). Conclusions: CPAP therapy with or without two weeks of the SA had a similar effect on CPAP use, sleep quality, daytime sleepiness, and nasal obstruction. The SA may have a tendency to improve daytime sleepiness, but needs further study with a longer duration of treatment.

Case report of new-onset obstructive sleep apnea after carbon monoxide poisoning

Obstructive sleep apnea (OSA) is characterized by repetitive intermittent oxygen desaturation during sleep. Carbon monoxide poisoning (COP) is the second most common cause of death among non-medicinal poisonings, and oxygen therapy is the current standard of treatment for COP. We herein report a case of a 50-year-old woman diagnosed with severe OSA associated with COP. Both the OSA and COP gradually resolved by automatic continuous positive airway pressure (CPAP) therapy. New OSA symptoms appeared following the development of delayed encephalopathy after acute COP (DEACMP) 3 weeks later. Severe OSA was diagnosed 76 days after COP with an apnea–hypopnea index of 66 events/hour, and CPAP therapy was immediately administered. The patient’s DEACMP symptoms and OSA both improved with CPAP therapy (her apnea–hypopnea index decreased to 32.4 and 16.5 events/hour at 161 and 204 days after COP, respectively). To our knowledge, this is the first case report of OSA caused by COP based on the occurrence and disappearance of OSA symptoms and laboratory findings associated with the emergence and improvement of DEACMP.

Respiratory failure: technical means for diagnosis and respiratory support

The necessity of early diagnosis of respiratory diseases, especially in the context of the COVID-19 pandemic, by means of pulse oximetric screening and monitoring has been substantiated. The expediency of using portable pulse oximeters by therapists and general practitioners has been shown. The main respiratory diseases accompanied by respiratory failure, which can be detected in time by pulse oximetry, are the chronic obstructive pulmonary disease and the obstructive sleep apnea-hypopnea syndrome. Early detection of these diseases is an important task because of the mild symptoms of these diseases in the early stages, and as a result, the prevalence of late diagnosis. Special attention is given to the pulse oximetry for COVID-19 detection, as this infection is also accompanied by respiratory failure. The use of oxygen concentrators and auto CPAP devices for the treatment of respiratory failure as well as rehabilitation has been argued. The effectiveness of the appointment of long-term oxygen therapy using oxygen concentrators for patients with chronic obstructive pulmonary disease, CPAP therapy using automatic CPAP devices for patients with obstructive sleep apnea-hypopnea syndrome with mandatory pulse oximetry monitoring has been confirmed. The analysis of 120 cases of treatment of moderate and severe COVID-19 cases complicated by the pneumonia has been carried out. The efficiency of the use of oxygen concentrators for supplying oxygen to patients at a flow rate not more than 5 l/min has been proven. It has been found that no more than 10 % of patients needed an oxygen flow rate more than 5 l/min. At the same time, the possibility of using CPAP devices for non-invasive ventilation of lungs using full-face masks has been shown. The expediency of using oxygen concentrators and CPAP devices for the rehabilitation of patients after COVID-19 has been noted.

Lung deposition and systemic bioavailability of dose delivered to smoker compared with non-smoker COPD subjects.

Inhaled drugs are the most commonly used class of medications for COPD subjects. No studies have been performed to assess the influence of smoking on lung deposition of aerosolized medication, especially for the exacerbated COPD subject. The present study aimed to assess the influence of smoking on the lung deposition of the aerosol delivered to exacerbated COPD subjects. Twenty-four exacerbated COPD subjects using automatic continuous positive airway pressure (Auto-CPAP), 12 smokers (six females) and 12 non-smokers (six females) were recruited in the study. The subjects participated in the study received four salbutamol study doses; 1200µg (12 puffs 100µg/puff) of salbutamol emitted from pMDI canister connected to AeroChamber MV spacer; 1200µg of salbutamol emitted from pMDI canister connected to Combihaler spacer; 1mL of salbutamol respirable solution (5000µg/mL) nebulized by Aerogen Solo connected to its T-piece; and 1mL of salbutamol respirable solution nebulized by Aerogen Solo connected to Combihaler spacer with 2 puffs salbutamol MDI (200µg salbutamol) before nebulisation. The subjects were randomised to receive the four selected dose-adaptor combination in a sealed envelope design on days 1, 3, 5 and 7. A washout period of 24hours was provided between each salbutamol dosing. Auto-CPAP was adjusted at non-invasive ventilation mode with the integrated heated humidifier, as a source of humidity. Urine samples were provided by subjects, 30minutes and cumulatively 24hours post inhalation, as an index of the relative and systemic bioavailability, respectively, and aliquots were retained for salbutamol analysis using solid-phase extraction and high-performance liquid chromatography (HPLC). On day 2 of the study, a collecting filter was placed between the aerosol generator and the subject's mask so that the subjects would not inhale the salbutamol delivered. The same study doses and/or adapters were delivered to each subject, with filters changed with each dose-adapter combination. Salbutamol entrained on the filter was desorbed to be analysed by the HPLC. Significantly higher lung deposition (30minutes urinary salbutamol) was detected with the non-smoker compared with smokers (P<.05). Significantly higher systemic bioavailability (pooled 24-hour urinary salbutamol) for smokers compared with non-smokers was found with Aerogen Solo connected to its T-piece and CombiHaler spacer with pMDI (P<.05) only. Significantly higher amount desorbed from the ex-vivo filter were found from pMDI with both spacers in non-smokers (P<.05) compared with the smokers. The study demonstrated that smoking reduced the lung deposition of inhaled salbutamol delivered by nebulizer or pMDI. However, the smoking effect on cytochrome p450 was observed to increase systemic absorption of the ingested portion of the inhaled dose. The lower lung deposition and possible higher systemic absorption should be taken into consideration while prescribing inhaled medication to COPD smokers especially exacerbated patients that need ventilation. Further studies are needed.

Treatment of superimposed preeclampsia on chronic hypertension in a twin pregnancy with automatic continuous positive airway pressure: a case report

BackgroundObstructive sleep apnoea (OSA) is related with adverse pregnancy outcomes, including preeclampsia. However, there are small studies about treatment of OSA with automatic continuous positive airway pressure (CPAP) in adverse obstetric outcomes.Case presentationWe introduce a case of 34 year old twin pregnant woman diagnosed with superimposed preeclampsia on chronic hypertension at 28 + 1/7 weeks of gestation. A level III polysomnography showed obstructive sleep apnoea, and automatic CPAP was applied. After the CPAP treatment concomitant with an antihypertensive drugs, both blood pressure and urinary protein concentration were reduced. The pregnancy safely continued for 49 days (to 35 + 1/7 weeks), with stable blood pressure, allowing prolongation of gestation of the foetuses.ConclusionThis is the first case to report OSA with preeclampsia in a twin pregnancy. Our results suggest that automatic CPAP as an adjunct treatment to antihypertensive drugs may be beneficial in controlling blood pressure in early-onset preeclampsia associated with OSA.

1234 Constrictive Pericarditis, an unlikely cause of Central Sleep Apnea

Abstract Introduction Central sleep apnea (CSA) and Cheyne stokes respiration (CSR) is a well-recognized complication of heart failure across multiple New York Heart Association functional classes. We present a case of CSA associated with constrictive pericarditis and normal systolic function. Report of Case 43-year-old male with past medical history of severe obstructive sleep apnea noted to have high residual apnea-hypopnea index (AHi) while using automatic continuous positive airway pressure, suspected to be central events. The patient also had progressive dyspnea on exertion, chest pain, and bilateral transudative pleural effusions. Pulmonary function testing was normal. He underwent a split night PSG which demonstrated severe OSA with AHi 81/hour during baseline. With CPAP titration, AHi was 30/hr, with predominately central events. Transthoracic echocardiogram demonstrated reduced stroke volume (LVOT VTI .085), dilated IVC, and EF 55%, septa! bounce, and annulus reversus (possible constriction). Right and left heart catheterization showed equalization of the diastolic pressures (RA 35 mm Hg, RV 48/30, PA 49/30, PCWP 29, Cl 1.6, SVR 1118 dynes, PVR 216 dynes), no coronary disease, and codominant system. Technetium 99 pyrophosphate scan demonstrated symmetric uptake in left and right ventricles, but abnormal thickening of pericardium suspicious for constrictive pericarditis. His symptoms progressed despite aggressive medical therapy and he was ultimately taken to surgery for pericardiectomy where it was noted his pericardium was extremely thickened and densely adhered to the myocardium, consistent with constrictive pericarditis. There was immediate improvement in hemodynamic status post-operatively. At post discharge follow up, he was NYHA class I, with resolution of all signs of heart failure. Repeat polysomnogram demonstrated persistent OSA, but resolution of CSA at baseline and with CPAP. Conclusion Constrictive pericarditis has not previously been reported as a cause of CSA or CSR. This patient had complete resolution of his heart failure symptoms with definitive resection of his pericardium.

Adaptive servo-ventilation therapy does not favourably alter sympatho-vagal balance in sleeping patients with systolic heart failure and central apnoeas: Preliminary data

BackgroundIn contrast to continuous positive airway pressure (CPAP), the use of adaptive servo-ventilation (ASV) for treatment of central sleep apnoea (CSA) was associated with increased mortality in patients with chronic systolic heart failure (CHF). In order to characterize the interplay between sleep-disordered breathing, CHF and sympathovagal balance (SVB) this study investigated the effect of nocturnal CPAP and ASV on SVB in CSA patients with or without CHF. MethodsThirty-seven patients with ongoing positive airway pressure therapy (CPAP or ASV) for CSA (17 patients with systolic CHF - left ventricular ejection fraction <50% - and 20 patients with CSA but no CHF) underwent evaluation of SVB (spectral analysis of heart rate -HRV- and diastolic blood pressure variability) during full nocturnal polysomnography. The night was randomly split into equal parts including no treatment (NT), automatic CPAP and ASV. Data analysis was restricted to stable N2 sleep. ResultsIn patients with CSA and systolic CHF, neither automatic CPAP nor ASV showed favourable effects on parameters reflecting SVB during N2 sleep (all p > 0.05). In contrast, in subjects with CSA without CHF automatic CPAP, but not ASV, favourably altered SVB by decreasing the low frequency and increasing the high frequency component of HRV (both p = 0.03). ConclusionsEffects of various modes of positive airway pressure therapy of CSA on SVB during sleep depend on the mode of pressure support and underlying cardiac function. Automatic CPAP but not ASV favourably influences SVB in subjects without CHF, whereas both interventions leave SVB unchanged in patients with CHF.

Extended evaluation of the efficacy of a proactive forced oscillation technique-based auto-CPAP algorithm.

Previous studies revealed substantially varying therapy efficacy of automatic continuous positive airway pressure (APAP) devices in the treatment of obstructive sleep apnea (OSA). We evaluated the efficacy of a new APAP device using the forced oscillation technique (FOT) to evaluate upper airway obstruction during apneas and flow contour analyses during hypopneas. Forty-six initially diagnosed OSA patients were included and the pressure range was set from 5 to 20hPa. Therapy efficacy was assessed based on the reduction of apnea-hypopnea index (AHI), improvement of objective sleep quality parameters, and the appropriateness of the device's pressure regulation. AHI and arousal index significantly decreased during APAP therapy (median [interquartile range]: AHI 36 [23-55] vs. 2 [1-6]/h, arousal index 30 [22-45] vs. 15 [10-19]/h, both p < 0.001). The amount of slow wave sleep (SWS) and rapid-eye-movement (REM) sleep significantly increased (SWS 20 [14-29] vs. 29 [19-34]%, REM 16 [11-21] vs. 24 [14-30]%, both p < 0.01). Most residual respiratory events during therapy were of central etiology and attributable to five patients, who presented with treatment-emergent central sleep apnea. The device's pressure regulation abolished most obstructive respiratory events (n = 6.7 residual obstructive events per patient). Of central respiratory events, 534/646 (83%) did not lead to pressure increases. This pilot study provides a proof of concept that the APAP device combining FOT and evaluation of flow contour allows for the suppression of obstructive events without relevant false reactions.

Nasal Obstruction Symptom Evaluation Score to Guide Mask Selection in CPAP-Treated Obstructive Sleep Apnea.

Nasal obstruction is frequently reported by patients with sleep apnea and complicates the choice of a nasal or oronasal mask for continuous positive airway pressure (CPAP) therapy. However, the type of interface used for the delivery of CPAP is crucial to ensure tolerance and compliance. The aim of this prospective pilot study was to identify whether the validated Nasal Obstruction Symptom Evaluation (NOSE) score rated at CPAP initiation was associated with the type of mask used after 4 months of treatment. Patients completed the NOSE questionnaire before initiation with automatic CPAP. The mask used (nasal/oronasal) after 4 months was documented. In total, 198 consecutive patients with sleep apnea were included. NOSE score (>50/100) was independently associated with the use of an oronasal mask at 4 months (sensitivity, 34.8%; specificity, 87.5%). The NOSE questionnaire could be a simple decision-making tool to guide the choice of mask during CPAP initiation.

Abstract TMP88: High Accuracy of Auto-CPAP for Obstructive Sleep Apnea in Acute Stroke Patients

Background: Obstructive sleep apnea (OSA) is very common in acute stroke patients and has been associated with a poor short-term and long-term outcome. Polysomnography (PSG) is the gold standard diagnostic method for OSA, but it is not feasible as a routine for all acute stroke patients. Therefore, it is essential to validade alternative methods to accurately diagnose OSA in acute stroke patients. The newest generation of automatic continuous positive airway pressure (auto-CPAP) devices innovates by the possibility of detecting the different types of respiratory events. However, the accuracy of auto-CPAP devices for OSA diagnosis has never been tested in comparison to PSG in the acute stroke setting. The main objective of this study was to evaluate the accuracy of an auto-CPAP device to diagnose OSA and to validate its algorithm of respiratory events detection to diagnose OSA in patients during the acute phase of stroke. Methods: A sleep study was performed with PSG and auto-CPAP device, simultaneously, within the first 48 hours after the acute stroke onset. The Receiver Operating Characteristic Curve (ROC), C-statistics, Spearman correlation coefficient, and intraclass correlation coefficient were analyzed. Results: We prospectively evaluated 31 adult patients with acute stroke. The mean age was 59.7 ± 12 years and 60% were males. All patients used auto-CPAP for longer than 4 hours. The PSG revealed an apnea-hypopnea index (AHI) mean of 34 ± 41 events/h, and the auto-CPAP showed an AHI of 18 ± 16 events/h. The area under the ROC curve for OSA diagnosis by the auto-CPAP was above 0.90, with sensitivity and specificity above 80% for each AHI value. The Spearman correlation coefficients (rs) of the AHI, of the hypopnea index, of the obstructive apnea index and of the central apnea index were 0.92; 0.89; 0.63 and 0.62, respectively. The intraclass correlation coefficients between device-detected and PSG manually scored events were 0.60 for AHI, 0.64 for hypopnea index, and 0.45 for apnea index. Conclusion: The auto-CPAP showed an excellent accuracy for the diagnosis of OSA and it was well tolerated by acute stroke patients. Our results suggest that auto-CPAP should be considered as the preferred diagnostic tool for OSA diagnosis during the acute phase of stroke.

Titration with automatic continuous positive airway pressure in obstructive sleep apnea

Background and objectiveAutotitrating positive airway pressure (APAP) is an accepted titration method to determine the optimal positive airway pressure (PAP), for the treatment of obstructive sleep apnea (OSA). The required duration of APAP monitoring to determine a fixed continuous positive airway pressure level still remains to be established. We aimed to evaluate the variation in PAP level, delivered by APAP devices, at different periods of treatment, to determine the APAP treatment duration required to reach an effective and stable PAP level. MethodsA cross-sectional study of 62 patients newly diagnosed with OSA were evaluated after 3 months of APAP therapy. APAP data corresponding to the first day (D1), first week (W1), seventh week (W7) and twelfth week (W12) under APAP therapy was collected. For the analysis of the pressure behaviour, the difference of P95th pressure level between W12 and W7 (P W12–W7), W12 and W1 (P W12–W1) and W12 and D1 (P W12–D1) was calculated. ResultsThere was a high correlation in P95th pressure level between D1 and W12 (r=0.771; p>0.0001), W1 and W12 (r=0.817; p>0.0001), and W7 and W12 (r=0.926; p>0.0001). This correlation progressively increased with APAP use. A significance difference was found in concordance between P W12–W7 and P W12–D1 (p=0.046) within the pressure range ±2cmH2O. However there was no significant difference in concordance between P W12–W7 and P W12–W1. ConclusionsOne week of APAP therapy seems sufficient to determine an effective and stable PAP level, within the pressure range ±2cmH2O.

Comparative study on optimal continuous positive airway pressure and predicted continuous positive airway pressure in obstructive sleep apnoea

Background: Continuous positive airway pressure (CPAP) is the first line non-invasive and safest treatment of obstructive sleep apnoea (OSA). Optimal CPAP therapy prescribed is obtained by manual titration in lab setting. Due to lack of data in Indian population predicted CPAP pressure proposed by Hoffstein is used using body mass index (BMI), neck circumference (NC) and apnoea-hypopnoea index (AHI) to correlate with the optimal pressure by automatic CPAP titration.Methods: The study was of retrospective and observational type. It included OSA patients diagnosed by overnight polysomnography (PSG) who had undergone automatic CPAP titration. The correlation of optimal pressure of automatic CPAP and predicted CPAP was studied.Results: A total of 30 patients were included in the study of which 23 were males and 7 were females. It was found that 28 patients had severe OSA and 2 had moderate OSA. AHI significantly improved (P = 0.000) with automatic CPAP titration. The mean CPAP predicted pressure (8.77±2.05) was found lower than the therapeutic optimal pressure (13.03±3.18) prescribed and the value exceeded the range ±2 in 76% of patients.Conclusions: Use of automatic CPAP limits the role for predicted formula for in lab titration/unattended home setting and patients who don’t undergo CPAP titration study, reducing the cost of testing. However, the predicted pressure could be used as a starting pressure for initiation of CPAP titration in lab setting for manual titration.

In-Vitro Characterization of the Aerosolized Dose During Non-Invasive Automatic Continuous Positive Airway Pressure Ventilation

Many devices (e.g., nebulizers and spacers) are used to deliver aerosol in a non-invasive ventilation circuit (NIV) without any special recommendation. The aim of the present work was to compare the doses delivered from seven different aerosol delivery systems when placed in the NIV using automatic continuous positive airway pressure (Auto-CPAP). Three spacers and three vibrating mesh nebulizers were compared to a Sidestream jet nebulizer (SIDE). Each device was placed proximal to a breathing simulator in a standard NIV circuit with a 500 ml tidal volume, 15 breaths/min and a 1:3 inspiratory-expiratory ratio. Two ml of salbutamol solution containing 10,000 μg was nebulized using Aerogen Pro (PRO), Aerogen Solo (SOLO), NIVO and SIDE. Twelve metered dose inhaler doses, containing 100 μg salbutamol each, were delivered using AeroChamber MV (AC), AeroChamber Vent (VC) and AeroChamber Mini (MC). Total emitted dose (TED) and its percentage were determined. Aerodynamic droplet characteristics were measured using cooled Andersen Cascade Impactor. The vibrating mesh nebulizers used had significantly more (p < 0.001) TED compared to the jet nebulizer. The spacers used had higher TED % (p < 0.001) compared to the nebulizers. The fine particle fraction of SIDE was the highest (p = 0.021) and mass median aerodynamic diameter of the spacers was the smallest (p = 0.001). The fine particle dose from vibrating mesh nebulizers was the greatest (p = 0.02). Aerosol delivery in Auto-CPAP NIV is feasible; however, aerosol delivery method should be chosen or substituted with care. 2 mg delivered from a spacer would be equivalent to 3 mg nebulized from a vibrating mesh nebulizer and 5 mg nebulized from a Sidestream.

Effect of APAP and heated humidification with a heated breathing tube on adherence, quality of life, and nasopharyngeal complaints.

Positive airway pressure (PAP) therapy adherence can be affected by rhinitis sicca and xerostomia complaints. Additional heated humidification (HH) is the appropriate method when such complaints arise. The aim of this study was to determine if HH with a supplementary heated breathing tube can increase adherence, reduce subjective nasopharyngeal complaints (NPC), and improve sleepiness (ESS: Epworth Sleepiness Scale) and quality of life (FOSQ: Functional Outcome of Sleep Questionnaire). We subdivided 72 obstructive sleep apnea (OSA) patients into two groups before therapy initiation. The NPC risk group consists of subjects with NPC and the low-risk group without. The risk group was identified by a score of >9 in a 5-item 25-point NPC questionnaire and pathological ESS. All patients were eligible for automatic CPAP devices (APAP), which were randomly configured with or without HH during 6 weeks. The adherence differences with and without HH were not significant in the NPC risk group (330 ± 103 vs. 281 ± 118 min/night) and in the low-risk group (330 ± 116 vs. 321 ± 89). NPC and ESS scores in the risk group were both significantly reduced with HH. Daily function (FOSQ) in the risk group was significantly improved with HH (90.0 ± 11.9 vs. 82.0 ± 12.0 (p < 0.05)). HH showed a tendency to improve APAP adherence. The adherence in both groups was quite high, and for that reason, it is difficult to show a statistically significant effect. A differentiation into NPC risk groups before starting PAP treatment is useful. HH reduces side effects and sleepiness and improves quality of life in an NPC risk group.

Comparative assessment of several automatic CPAP devices' responses: a bench test study.

Automatic continuous positive airway pressure (APAP) devices adjust the delivered pressure based on the breathing patterns of the patient and, accordingly, they may be more suitable for patients who have a variety of pressure demands during sleep based on factors such as body posture, sleep stage or variability between nights. Devices from different manufacturers incorporate distinct algorithms and may therefore respond differently when subjected to the same disturbed breathing pattern. Our objective was to assess the response of several currently available APAP devices in a bench test.A computer-controlled model mimicking the breathing pattern of a patient with obstructive sleep apnoea (OSA) was connected to different APAP devices for 2-h tests during which flow and pressure readings were recorded. Devices tested were AirSense 10 (ResMed), Dreamstar (Sefam), Icon (Fisher & Paykel), Resmart (BMC), Somnobalance (Weinmann), System One (Respironics) and XT-Auto (Apex). Each device was tested twice.The response of each device was considerably different. Whereas some devices were able to normalise breathing, in some cases exceeding the required pressure, other devices did not eliminate disturbed breathing events (mainly prolonged flow limitation). Mean and maximum pressures ranged 7.3–14.6 cmH2O and 10.4–17.9 cmH2O, respectively, and the time to reach maximum pressure varied from 4.4 to 96.0 min.Each APAP device uses a proprietary algorithm and, therefore, the response to a bench simulation of OSA varied significantly. This must be taken into account for nasal pressure treatment of OSA patients and when comparing results from clinical trials.