Nocturnal Oxygen Therapy Research Articles

Prevention of Morbidity in Sickle Cell Disease (POMS2a)\u2014overnight auto-adjusting continuous positive airway pressure compared with nocturnal oxygen therapy: a randomised crossover pilot study examining patient preference and safety in adults and children

DesignThis randomised crossover trial compared nocturnal auto-adjusting continuous positive airway pressure (APAP) and nocturnal oxygen therapy (NOT) in adults and children with sickle cell anaemia, with patient acceptability as the primary outcome. Secondary outcomes included pulmonary physiology (adults), safety, and daily pain during interventions and washout documented using tablet technology.MethodsInclusion criteria were age > 8 years and the ability to use an iPad to collect daily pain data. Trial participation was 4 weeks; week 1 involved baseline data collection and week 3 was a washout between interventions, which were administered for 7 days each during weeks 2 and 4 in a randomised order. Qualitative interviews were transcribed verbatim and analysed for content using a funnelling technique, starting generally and then gaining more detailed information on the experience of both interventions. Safety data included routine haematology and median pain days between each period. Missing pain day values were replaced using multiple imputation.ResultsTen adults (three female, median age 30.2 years, range 18–51.5 years) and eleven children (five female, median age 12 years, range 8.7–16.9 years) enrolled. Nine adults and seven children completed interviews. Qualitative data revealed that the APAP machine was smaller, easier to handle, and less noisy. Of 16 participants, 10 preferred APAP (62.5%, 95% confidence interval (CI) 38.6–81.5%). Haemoglobin decreased from baseline on APAP and NOT (mean difference −3.2 g/L (95% CI −6.0 to −0.2 g/L) and −2.5 g/L (95% CI −4.6 to 0.3 g/L), respectively), but there was no significant difference between interventions (NOT versus APAP, 1.1 (−1.2 to 3.6)). Pulmonary function changed little. Compared with baseline, there were significant decreases in the median number of pain days (1.58 for APAP and 1.71 for NOT) but no significant difference comparing washout with baseline. After adjustment for carry-over and period effects, there was a non-significant median difference of 0.143 (95% CI −0.116 to 0.401) days additional pain with APAP compared with NOT.ConclusionIn view of the point estimate of patient preference for APAP, and no difference in haematology or pulmonary function or evidence that pain was worse during or in washout after APAP, it was decided to proceed with a Phase II trial of 6 months APAP versus standard care with further safety monitoring for bone marrow suppression and pain.Trial registrationISRCTN46078697. Registered on 18 July 2014

Oxygen therapy in COPD and interstitial lung disease: navigating the knowns and unknowns.

Domiciliary oxygen therapy is often prescribed for patients with hypoxaemia due to advanced lung disease, most commonly chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Long-term oxygen therapy (LTOT) trials conducted in patients with COPD in the 1980s remain the basis for clinical decisions and guideline recommendations regarding LTOT for patients with non-COPD conditions as there is a lack of high-quality evidence concerning its use in the non-COPD population. There is also a lack of evidence for the use of ambulatory and nocturnal oxygen therapy in patients with isolated exertional and nocturnal hypoxaemia. These deficiencies pose significant challenges in patient care, with consequent discrepancies in guideline recommendations and clinical approaches. In recent years, new studies have been and are currently being conducted to fill the gaps in our understanding and use of domiciliary oxygen therapy for other indications, including ILD. This article provides a comparison of the epidemiology and significance of hypoxaemia in patients with COPD and ILD, with an up-to-date review of current evidence regarding the role of different types of domiciliary oxygen therapy in these conditions.

Vascular responses to hypoxia are not impaired in obstructive sleep apnoea patients free of overt cardiovascular disease.

What is the central question of this study? Does treatment of obstructive sleep apnoea (OSA) with nocturnal oxygen or continuous positive airway pressure (CPAP) improve hypoxic vascular responses, which are reportedly impaired in OSA? What is the main finding and its importance? Cerebrovascular and cardiovascular hypoxic responses were not impaired in OSA patients free of overt cardiovascular disease and known risk factors, and were not altered by nocturnal oxygen or CPAP treatment. We conclude that this OSA patient phenotype has normal vascular responses to hypoxia and is unlikely to obtain long term cardiovascular benefits from nocturnal oxygen or CPAP therapy. Cerebral blood flow (CBF) and cardiovascular responses to hypoxia are reportedly impaired in obstructive sleep apnoea (OSA) patients and corrected by continuous positive airway pressure (CPAP), beneficial effects that are ascribed to correction of OSA-related intermittent hypoxia (IH). However, CPAP corrects both IH and ancillary OSA features (i.e. intermittent hypercapnia, sympathetic activation, blood pressure surges, negative intrathoracic pressure swings and sleep fragmentation). Whether correction of these ancillary OSA features contribute to CPAP's beneficial effects on vascular hypoxic responses is unknown. Nocturnal oxygen corrects OSA-induced IH, but apnoeas and ancillary features persist. Thus, we examined the effects of nocturnal oxygen and CPAP on cerebrovascular and cardiovascular hypoxic responses in untreated OSA patients. Responses were assessed in 52 OSA patients free of overt cardiovascular disease and known risk factors at baseline, after 2weeks of nocturnal oxygen (n=26) or no treatment (n=26), and after ∼4weeks of CPAP treatment (n=40). Twenty-two age-matched controls were assessed at baseline and follow-up visits. Resting, isocapnic euoxia mean blood pressure was decreased following nocturnal oxygen (-3.6±6.0mmHg; P=0.006) and CPAP (-4.5±7.5mmHg; P<0.001) while cerebrovascular conductance was increased with CPAP (P=0.001). However, these changes were not different from controls. Unexpectedly, OSA patients and controls had similar hypoxic vascular responses at baseline that were not changed by either nocturnal oxygen or CPAP. We conclude that OSA patients free of overt cardiovascular disease and known risk factors did not have impaired cerebrovascular or cardiovascular responses to hypoxia and are unlikely to obtain long term cardiovascular benefits from nocturnal oxygen or CPAP therapy.

The effect of isolated nocturnal oxygen desaturations on serum hs-CRP and IL-6 in patients with chronic obstructive pulmonary disease.

A majority of patients with chronic obstructive pulmonary disease (COPD) die of cardiovascular disease (CVD), yet the mechanisms responsible for this association are not fully understood. It remains unknown if isolated nocturnal oxygen desaturation (iNOD) could be one of the potential pathways by which the 'inflammatory COPD' phenotype leads to CVD. We aimed to evaluate if COPD patients who meet the Medicare guidelines for nocturnal oxygen therapy (iNOT+) had higher serum hs-CRP and IL-6 than those who did not meet the guidelines for iNOT (iNOT-). Patients with moderate to severe COPD (ie FEV1<80% and FEV1/FVC<70), who were not on oxygen, underwent nocturnal oximetry on room air. Serum IL-6 and hs-CRP were collected the morning after the nocturnal oximetry testing. A total of 28 patients were included in the study, 8 of whom had more than 5 minutes and 5% of their sleep time spent at oxygen saturation less than 88% and constituted the iNOT+ group. Only serum hs-CRP was significantly higher in iNOT+ than iNOT- (P=0.050). There was no difference in the rate of COPD exacerbations at one and three months, or five-year survival between the groups (P>0.3). COPD patients who have more than 5 minutes and 5% of their sleep time spent at oxygen saturation less than 88% have increased hs-CRP, which is associated with increased risk of future CVD.

Polysomnographic findings in Rett syndrome.

Rett syndrome (RS) is a severe neurodevelopment disorder associated with abnormal breathing during wakefulness and disturbed nocturnal behaviour. Breathing abnormalities during daytime have been extensively reported but polysomnographic (PSG) findings have been poorly studied. Consecutive patients with RS carrying distinct mutations in MECP2 gene, who underwent a PSG between October 2014 and January 2018, were included in the study. Clinical and PSG data were collected. Seventeen RS girls, mean age 9.5±2.8 years, were included in the study. Mean total sleep time was 366±102min. Mean sleep efficiency was reduced (66±19%) with only 3 girls presenting a sleep efficiency above 80%. Wake after sleep onset was increased (33±20%) with an arousal index of 7±6 events/hour. Sleep stages were altered with a normal N1 (2±3%), a decreased N2 (34±20%), an increase of N3 (51±23%) and a decrease of REM sleep (12±9%). Mean apnea hypopnea index (AHI) was increased at 19±37 events/hour, with a predominance of obstructive events. Thirteen patients had an AHI>1.5 event/hour. Four patients had an obstructive AHI >10 events/hour with one patient having associated tonsillar hypertrophy. Two patients had predominant severe central apneas (central AHI 53 and 132 events/hour) which resolved with noninvasive ventilation and nocturnal oxygen therapy respectively. Girls with RS have poor sleep quality with alterations in slow wave and REM sleep stages. Obstructive respiratory events are uncommon in patients without adenotonsillar hypertrophy. Central respiratory events are rare. Longitudinal studies should help understanding the natural history of sleep disturbances in RS and their relationship with the neurocognitive decline.

Home Oxygen in Chronic Obstructive Pulmonary Disease.

Two landmark trials conducted more than 35 years ago provided scientific evidence that, under very specific circumstances, long-term oxygen therapy (LTOT) may prolong life. These two trials enrolled 290 patients with chronic obstructive pulmonary disease and severe daytime hypoxemia documented by direct arterial blood gas measurement. From that time, LTOT became a standard of care, and the indications for oxygen therapy expanded to include nocturnal oxygen therapy for isolated nocturnal oxygen desaturation, ambulatory oxygen to correct exercise-induced desaturation, and short-burst oxygen to relieve dyspnea. In most cases, the rationale for broadening the indications for oxygen therapy is that, if hypoxemia exists, correcting it by increasing the FiO2 should help. However, with the exception of LTOT in severely hypoxemic patients with chronic obstructive pulmonary disease, randomized controlled trials of oxygen therapy have failed to demonstrate clinically significant benefits. Also, adherence to LTOT is usually suboptimal. Important areas for future research include improving understanding of the mechanisms of action of supplemental oxygen, the clinical and biochemical predictors of responsiveness to LTOT, the methods for measuring and enhancing adherence to LTOT, and the cost-effectiveness of oxygen therapy. A standardization of terminology to describe the use of supplemental oxygen at home is provided.

Transfusion-related adverse events are decreased in pregnant women with sickle cell disease by a change in policy from systematic transfusion to prophylactic oxygen therapy at home: A retrospective survey by the international sickle cell disease observatory.

Sickle cell disease (SCD) in pregnancy can be associated with adverse maternal and perinatal outcomes. Furthermore, complications of SCD can be aggravated by pregnancy. Optimal prenatal care aims to decrease the occurrence of maternal and fetal complications. A retrospective, French, two‐center study compared two care strategies for pregnant women with SCD over two time periods. In the first study period (2005‐2010), the women were systematically offered prophylactic transfusions. In the second study period (2011‐2014), a targeted transfusion strategy was applied whenever possible, and home‐based prophylactic nocturnal oxygen therapy was offered to all the pregnant women. The two periods did not differ significantly in terms of the incidence of vaso‐occlusive events. Maternal mortality, perinatal mortality, and obstetric complication rates were also similar in the two periods, as was the incidence of post‐transfusion complications (6.1% in 2005‐2010 and 1.3% in 2011‐2014, P = .15), although no de novo alloimmunizations or delayed hemolysis transfusion reactions were observed in the second period. The results of this preliminary, retrospective study indicate that targeted transfusion plus home‐based prophylactic nocturnal oxygen therapy is safe and may decrease transfusion requirements and transfusion‐associated complications.

Central Sleep Apnea with Cheyne-Stokes Breathing in Heart Failure - From Research to Clinical Practice and Beyond.

Characterized by periodic crescendo-decrescendo pattern of breathing alternating with central apneas, Central sleep apnea (CSA) with Cheyne-Stokes Breathing represents a highly prevalent, yet underdiagnosed comorbidity in chronic heart failure (CHF). A diverse body of evidence demonstrates increased morbidity and mortality in the presence of CSB. CSB has been described in both CHF patients with preserved and reduced ejection fraction, regardless of drug treatment. Risk factors for CSB are older age, male gender, high BMI, atrial fibrillation and hypocapnia.The pathophysiology of CSB has been explained by the loop gain theory, where a controller (the respiratory center) and a plant (the lungs) are operating in a reciprocal relationship (negative feedback) to regulate a key parameter (partial pressure of carbon dioxide (pCO2)). The temporal interaction between these elements is dependent on the circulatory delay. Increased chemosensitivity/chemoresponsiveness of the respiratory center and/or augmented ascending non- CO2 stimuli from the C-fibers in the lungs (interstitial pulmonary edema), overly efficient ventilation when breathing at low volumes and prolonged circulation time are involved. An alternative hypothesis of CSB being an adaptive response of the failing heart has its merits as well. The clinical manifestation of CSB is usually poor, lacking striking symptoms and complaints. Witnessed apneas and snoring are infrequently reported by the sleep partner. Sometimes patients may report poor sleep quality with frequent awakenings, paroxysmal nocturnal dyspnea and frequent urination at night. Standard instrumental and laboratory studies, performed in CHF patients, may present clues to the presence of CSB. Concentric remodeling of the left ventricle and dilated left atrium (echocardiography), high BNP and C-reactive protein levels, increased ventilation-carbon dioxide output (VEVCO2) and lower end-tidal CO2 (cardiopulmonary exercise testing), reduced diffusion capacity (pulmonary function testing) and hypocapnia (blood-gas analysis) may indicate the presence of CSB.CSB and cardiovascular disease are probably linked through bidirectional causality. Cyclic variations in heart rate, blood pressure, respiratory volume, partial pressure of arterial oxygen (pO2) and pCO2 lead to sympathetic-adrenal activation. The latter worsens ventricular energetism and survival of cardiomyocytes and exerts antiarhythmogenic effects. It causes cardiac remodeling, potentiating the progression and the lethal outcome in CHF patients. Several treatment modalities have been proposed in CSB. The most commonly used are continuous positive airway pressure (CPAP), adaptive servoventilation (ASV) and nocturnal home oxygen therapy (HOT). Novel therapies like nocturnal supplemental CO2 and phrenic nerve stimulation are being tested recently. The current treatment recommendations (by the American Academy of Sleep Medicine) are for CPAP and HOT as standard therapies, while ASV is an option only in patients with EF>45%. BPAP (bilevel device) remains an option only when there is no adequate response to previous modes of treatment. Acetazolamide and theophylline are options only after failing the above modalities and if accompanied by a close follow-up.

P156 Risk of cardiac arrhythmias in lowlanders with COPD travelling to high altitude. Randomized trial of nocturnal oxygen therapy

P156 Risk of cardiac arrhythmias in lowlanders with COPD travelling to high altitude. Randomized trial of nocturnal oxygen therapy

Multi-center, randomized, placebo-controlled trial of nocturnal oxygen therapy in chronic obstructive pulmonary disease: a study protocol for the INOX trial

BackgroundLong-term oxygen therapy (LTOT) is the only component of the management of chronic obstructive pulmonary disease (COPD) that improves survival in patients with severe daytime hypoxemia. LTOT is usually provided by a stationary oxygen concentrator and is recommended to be used for at least 15–18 h a day. Several studies have demonstrated a deterioration in arterial blood gas pressures and oxygen saturation during sleep in patients with COPD, even in those not qualifying for LTOT. The suggestion has been made that the natural progression of COPD to its end stages of chronic pulmonary hypertension, severe hypoxemia, right heart failure, and death is dependent upon the severity of desaturation occurring during sleep. The primary objective of the International Nocturnal Oxygen (INOX) trial is to determine, in patients with COPD not qualifying for LTOT but who present significant nocturnal arterial oxygen desaturation, whether nocturnal oxygen provided for a period of 3 years decreases mortality or delay the prescription of LTOT.MethodsThe INOX trial is a 3-year, multi-center, placebo-controlled, randomized trial of nocturnal oxygen therapy added to usual care. Eligible patients are those with a diagnosis of COPD supported by a history of past smoking and obstructive disease who fulfill our definition of significant nocturnal oxygen desaturation (i.e., ≥ 30% of the recording time with transcutaneous arterial oxygen saturation < 90% on either of two consecutive recordings). Patients allocated in the control group receive room air delivered by a concentrator modified to deliver 21% oxygen. The comparison is double blind. The primary outcome is a composite of mortality from all cause or requirement for LTOT. Secondary outcomes include quality of life and utility measures, costs from a societal perspective and compliance with oxygen therapy. The follow-up period is intended to last at least 3 years.DiscussionThe benefits of LTOT have been demonstrated whereas those of nocturnal oxygen therapy alone have not. The INOX trial will likely determine whether supplemental oxygen during sleep is effective in reducing mortality, delaying the need for LTOT and improving health-related quality of life in patients with COPD who desaturate overnight.Trial registrationCurrent Controlled Trials ISRCTN50085100; ClinicalTrials.gov NCT01044628 (date of registration: January 6, 2010).

Management of Sleep Apnea Syndromes in Heart Failure.

Central sleep apnea (CSA) and obstructive sleep apnea (OSA) are prevalent in heart failure (HF) and associated with a worse prognosis. Nocturnal oxygen therapy may decrease CSA events, sympathetic tone, and improve left ventricular ejection fraction, although mortality benefit is unknown. Although treatment of OSA in patients with HF is recommended, therapy for CSA remains controversial. Continuous positive airway pressure use in HF-CSA may improve respiratory events, hemodynamics, and exercise capacity, but not mortality. Adaptive servo ventilation is contraindicated in patients with symptomatic HF with predominant central sleep-disordered events. The role of phrenic nerve stimulation in CSA therapy is promising.

Effect of Nocturnal Oxygen Therapy on Electrocardiographic Changes Among Patients with Congestive Heart Failure

Introduction: Nocturnal hypoxia is an important factor in increasing the risk of mortality in patients with chronic heart failure and is associated with atrial and ventricular arrhythmias. In addition, QT dispersion (QTd) is used as a prognostic sign in determining future malignant arrhythmias and sudden cardiac death. In the current study, we investigated the effect of nocturnal oxygen therapy (NOT) on electrocardiographic changes among patients with chronic heart failure. Methods: In this study, a consecutive of 154 patients (87 males and 67 females) known with chronic heart failure (EF ≤ 40%) were enrolled. The patients were administered NOT (oxygen flow of 2 L/min for 8 hours during sleeping). Electrocardiography was takenbefore and after the NOT, and RR interval, PR interval and QTd were measured each time. Results: The mean age of the participants was 61.3 ± 11.4 years. Our results revealed significant reduction in QTd (55.8 ± 7.5 vs. 61.4± 9.1 msec, P = 0.001) and heart rate (79.6 ± 4.7 vs. 76.8 ± 4.3, P = 0.001) in a patient’s electrocardiogram after NOT. Conclusions: In this study, NOT decreased heart rate and QTd in patients with chronic heart failure, but not PR interval, which could consequently decrease the risk of malignant arrhythmias and sudden cardiac death.

Adaptive servoventilation versus oxygen therapy for sleep disordered breathing in patients with heart failure: a randomised trial

BackgroundBoth adaptive servoventilation (ASV) and nocturnal oxygen therapy improve sleep disordered breathing (SDB), but their effects on cardiac parameters have not been compared systematically.Methods and results43 patients with chronic heart...

Impact of nocturnal oxygen therapy for central sleep apnea syndrome on nocturnal premature ventricular contractions

We report here a case of central sleep apnea syndrome associated with frequent nocturnal premature ventricular contractions (PVCs) that were successfully eliminated using nocturnal oxygen therapy. He was admitted to our hospital for chest discomfort during the night. The symptoms frequently woke him up during sleep. His electrocardiogram (ECG) showed sinus rhythm accompanied by PVCs. The 24 hour ambulatory ECG detected frequent PVCs during the night (more than 1000 beats/hour). Additionally, polysomnography demonstrated severe central sleep apnea syndrome, the so-called Cheyne-Stokes respirations (apnea-hypopnea index 48/ hour). He received oxygen at a rate of 2 liter/min only during sleep. After nocturnal nasal oxygen therapy, the PVCs became significantly fewer and his symptoms disappeared. This case report suggests the possibility of an impact of oxygen inhalation during sleep in patients with central SAS on the prevention of ventricular arrhythmias during both the daytime and night. However, further well-established randomized, controlled studies are needed to confirm these effects.

End-Tidal CO2 Tension Is Predictive of Effective Nocturnal Oxygen Therapy in Patients with Chronic Heart Failure and Central Sleep Apnea.

Central sleep apnea (CSA) is characterized by recurring cycles of crescendo-decrescendo ventilation during sleep, and enhances sympathetic nerve activity. Thus CSA has a prognostic impact in patients with chronic heart failure (CHF). Although nocturnal oxygen (O2) therapy decreases frequency of CSA and improves functional exercise capacity, it is also known that some non-responders to the therapy exist. We thus aimed to identify predictors of responders to nocturnal O2 therapy in CHF patients with CSA. In 12 CHF patients with CSA hospitalized at our department, sleep study was performed at 2 consecutive nights. Patients nasally inhaled O2 at either the first or second night in a randomized manner. To predict the percentage reduction in apnea-hypopnea index (%ΔAHI) in response to the nocturnal O2 therapy, we performed multiple regression analysis with a stepwise method with variables including age, brain-natriuretic peptide, circulation time, baseline AHI, hypercapnic ventilatory response and end-tidal carbon dioxide tension (PETCO2). Nocturnal O2 therapy significantly decreased AHI (from 32 ± 13 /h to 12 ± 10 /h, P < 0.0001). Among the possible predictors, PETCO2 was the only variable that is predictive of % changes in AHI. Receiver operating characteristics analysis determined 4.25% as the optimal cutoff PETCO2 level to identify responder to nocturnal O2 therapy (> 50% reduction of AHI), with 88.9% of sensitivity and 66.7% of specificity. In conclusion, PETCO2 is useful to predict the efficacy of O2 therapy in CHF patients with CSA, providing important information to the current nocturnal O2 therapy.

Impact of nocturnal oxygen therapy for central sleep apnea syndrome on nocturnal premature ventricular contractions

Impact of nocturnal oxygen therapy for central sleep apnea syndrome on nocturnal premature ventricular contractions

Study of sleep related respiratory disorders in patients with idiopathic pulmonary arterial hypertension

The effects of sleep-disordered breathing (SDB) and nocturnal hypoxemia on pulmonary hemodynamics have long interested physicians who manage patients with pulmonary arterial hypertension. The aim of the present study is to study the prevalence and identify the types of sleep related breathing disorders in patients with IPAH in the state of Kuwait. Patients and methods36 patients(32 females and 4 males) were included, the mean age was 35.2±17.3years, all patients were non-smokers and non-obese. All patients were subjected to routine investigations, Echocardiography, CT pulmonary angiography and full night polysomnography. All cases pulmonary hypertension related to cardiac disease or collagenic vascular disease or Thromboembolic disease were excluded. ResultsThe mean AHI was 13.8±8.3/h of sleep with OSA proved in 5 patients (13.9%) and CSR/CSA proved in 2 patients (5.56%). Nocturnal desaturation was more pronounced in the studied patient as 27 patients (75%) showed nocturnal desaturation. There was a significant correlation between SDB measures and baseline oxygen saturation, lowest oxygen saturation during walking and mean PAP. ConclusionSDB is significant in patients with IPAH and can affect the disease progression and the quality of life of those patients. All patients should undergo sleep study to identify patients who are in need of nocturnal oxygen therapy or in need for CPAP therapy in case of OSA.

Prevention of Morbidity in Sickle Cell Disease (POMS 2): A Pilot Study of Nocturnal Respiratory Support Shows That Auto-Adjusting Positive Airways Pressure Is Safe and Is Preferred to Oxygen Therapy

Despite the high prevalence of obstructive sleep apnea (OSA) and overnight hypoxia in sickle cell disease (SCD) patients, there are few data on treatment safety and efficacy, with controversy about the optimal management of these complications. Auto-adjusting positive airways pressure (APAP) has been shown to improve attention span and reduce pain episodes in children with sickle cell anemia (SCA) in a pilot randomized trial and there is observational evidence that nocturnal oxygen therapy (NOT) used for a period of at least six months in patients with SCD and severe nocturnal hypoxia is safe and easy to use.The Prevention of Morbidity in Sickle Cell Disease (POMS 2a) study is a National Institute for Health Research (NIHR) funded pilot feasibility trial to compare APAP with NOT in adults and children with SCD to establish the most acceptable treatment strategy and to determine short term safety of both interventions. We also assessed the feasibility of using an iPad app to collect daily pain scores.Methods: This was a cross-over interventional trial. Inclusion criteria were: age over 8 years, diagnosis of HbSS and ability to give informed consent and use an iPad. Evidence of overnight hypoxia and/or OSA was not necessary for inclusion in the trial. Each intervention was administered for a week in randomized order with a week of baseline data collection and a week of washout between the interventions. Tablet technology was used to collect daily pain scores and a detailed qualitative interview was performed after both interventions. These transcripts were analysed manually by two researchers using content analysis. Physiological and safety data included blood tests (routine hematology and biochemistry testing), urine protein measurements, oximetry, quality of life (using PedsQL), spirometry and lung volume measurements, which were measured at baseline and after each intervention. Adherence data was downloaded from the APAP machine and was self-reported for NOT.Results: Ten adults (3 female, mean age 31.7 years, 4 on hydroxyurea) and eleven children (5 female, mean age 11.9 years, 7 on hydroxyurea) were enrolled. APAP adherence data was available on 8 adults who completed 3 to 7 nights of APAP for a mean of 6.13 hours (range 4.49-7.76). Data was not available on 2 patients. One patient completed 3 days of APAP and was admitted two days later with a painful crisis and subsequent acute chest syndrome, they were subsequently withdrawn from the trial. One adult developed a pain crisis on day 2 of NOT which was self managed at home. Data on APAP adherence was available on nine children who completed APAP therapy for 3-7 nights for a mean of 5.9 hours (range 1.94-9.05), there was no data on 1 child and one did not tolerate APAP and stopped after one night. This child was admitted with a pain crisis three days after stopping APAP. Detailed quantitative interviews were completed on 19 participants. The majority of participants showed a preference for APAP because the machine was smaller, easier to handle and less noisy and noted that they slept better when using the APAP machine and were less fatigued, but some participants found the mask uncomfortable. Patients reported that NOT had a calming effect on them but they also reported that it was very noisy and caused dry nose, throat and mouth. There was no significance difference in hemoglobin, reticulocyte count, creatinine, erythropoietin, albumin creatinine ratio, bilirubin or lactate dehydrogenase at baseline and after either intervention. One patient showed a decrease in absolute reticulocyte count from 128x109 l to 53x 109/l after NOT therapy, with no change in hemoglobin. Mean overall pain days per week were 2.31 at baseline, 1.57 during APAP, 1.47 during NOT and 2.08 during washout. There was no difference in spirometry and lung volume measurements between baseline and post intervention. Pulse oximetry and Quality of Life was unchanged between baseline and after both interventionsConclusion: There were no safety concerns, in particular there was no evidence of erythroid suppression or rebound pain after 7-day application of APAP or nocturnal oxygen therapy. Tablet technology was acceptable to patients with satisfactory levels of completion. In view of patient preference for APAP the steering group has decided to proceed with a phase 2b randomized trial of six months therapy with APAP versus standard care to assess its effects on pain, quality of life and cognitive function. DisclosuresHoward:Pfizer: Consultancy; Novartis: Consultancy, Other: Travel Grant; Aes-Rx: Consultancy.

Effects of nocturnal oxygen therapy on heart function in SDB patients undergoing dialysis

There is a close relationship between sleep disordered breathing (SDB) and heart failure. We performed home oxygen therapy (HOT) in patients with SAS undergoing dialysis, and investigated its effects on the heart function. The subjects were 10 SDB patients on dialysis. On retiring at night, oxygen was transnasally administered at 1.0 L/min. The human atrial natriuretic peptide (hANP), brain natriuretic peptide (BNP), total protein, Alb, cholesterol and phosphorus levels were measured before the start of oxygen therapy and after 6 weeks. The mean SpO2 increased from 93.5% [91.5, 97.0] to 96.3% [94.8, 97.4] (median [interquartile range]) (p = 0.015). The hANP (p = 0.0039), BNP (p = 0.0098) and serum Alb (p = 0.015) levels significantly improved. There were no significant changes in the cholesterol, phosphorus or total protein levels. These results suggest that nocturnal oxygen therapy improves indices of heart failure, contributing to the prevention and treatment of heart failure in dialysis patients with SDB.

Long-term oxygen therapy

Long-term oxygen therapy (LTOT) is the provision of oxygen therapy to a patient at home for at least 15 hours a day, usually for the duration of the remainder of the individual’s life. There are at least 85 000 people prescribed home oxygen in England alone, and many of these patients are assessed and monitored in primary care, with the aid of respiratory specialists from secondary care within a multi-disciplinary team. This article outlines the indications and assessments required for the prescription of LTOT, the cautions and contraindications to home oxygen use, and the practicalities of instigation, delivery and monitoring. The article does not cover nocturnal oxygen therapy, ambulatory oxygen therapy or short-burst oxygen therapy.