CPAP Adherence, Mortality, and Progression-Free Survival in Interstitial Lung Disease and OSA

BACKGROUND

OSA, a common comorbidity in interstitial lung disease (ILD), could contribute to a worsened course if untreated. It is unclear if adherence to CPAP therapy improves outcomes.

RESEARCH QUESTION

Does adherence to CPAP therapy improve outcomes in patients with concurrent interstitial lung disease and OSA?

STUDY DESIGN AND METHODS

We conducted a 10-year retrospective observational multicenter cohort study, assessing adult patients with ILD who had undergone polysomnography. Subjects were categorized based on OSA severity into no/mild OSA (apnea-hypopnea index score < 15) or moderate/severe OSA (apnea-hypopnea index score ≥ 15). All subjects prescribed and adherent to CPAP were deemed to have treated OSA. Cox regression models were used to examine the association of OSA severity and CPAP adherence with all-cause mortality risk and progression-free survival (PFS).

RESULTS

Of 160 subjects that met inclusion criteria, 131 had OSA and were prescribed CPAP. Sixty-six patients (41%) had no/mild untreated OSA, 51 (32%) had moderate/severe untreated OSA, and 43 (27%) had treated OSA. Subjects with no/mild untreated OSA did not differ from those with moderate/severe untreated OSA in mean survival time (127 ± 56 vs 138 ± 93 months, respectively; P = .61) and crude mortality rate (2.9 per 100 person-years vs 2.9 per 100 person-years, respectively; P = .60). Adherence to CPAP was not associated with improvement in all-cause mortality risk (hazard ratio [HR], 1.1; 95% CI, 0.4-2.9; P = .79) or PFS (HR, 0.9; 95% CI, 0.5-1.5; P = .66) compared with those that were nonadherent or untreated. Among subjects requiring supplemental oxygen, those adherent to CPAP had improved PFS (HR, 0.3; 95% CI, 0.1-0.9; P = .03) compared with nonadherent or untreated subjects.

INTERPRETATION

Neither OSA severity nor adherence to CPAP was associated with improved outcomes in patients with ILD except those requiring supplemental oxygen.

The complex sleep apnea resolution study: a prospective randomized controlled trial of continuous positive airway pressure versus adaptive servoventilation therapy

INTRODUCTION

Prior studies show that adaptive servoventilation (ASV) is initially more effective than continuous positive airway pressure (CPAP) for patients with complex sleep apnea syndrome (CompSAS), but choosing therapies has been controversial because residual central breathing events may resolve over time in many patients receiving chronic CPAP therapy. We conducted a multicenter, randomized, prospective trial comparing clinical and polysomnographic outcomes over prolonged treatment of patients with CompSAS, with CPAP versus ASV.

METHODS

Qualifying participants meeting criteria for CompSAS were randomized to optimized CPAP or ASV treatment. Clinical and polysomnographic data were obtained at baseline and after 90 days of therapy.

RESULTS

We randomized 66 participants (33 to each treatment). At baseline, the diagnostic apnea-hypopnea index (AHI) was 37.7 ± 27.8 (central apnea index [CAI] = 3.2 ± 5.8) and best CPAP AHI was 37.0 ± 24.9 (CAI 29.7 ± 25.0). After second-night treatment titration, the AHI was 4.7 ± 8.1 (CAI = 1.1 ± 3.7) on ASV and 14.1 ± 20.7 (CAI = 8.8 ± 16.3) on CPAP (P ≤ 0.0003). At 90 days, the ASV versus CPAP AHI was 4.4 ± 9.6 versus 9.9 ± 11.1 (P = 0.0024) and CAI was 0.7 ± 3.4 versus 4.8 ± 6.4 (P < 0.0001), respectively. In the intention-to-treat analysis, success (AHI < 10) at 90 days of therapy was achieved in 89.7% versus 64.5% of participants treated with ASV and CPAP, respectively (P = 0.0214). Compliance and changes in Epworth Sleepiness Scale and Sleep Apnea Quality of Life Index were not significantly different between treatment groups.

CONCLUSION

Adaptive servoventilation (ASV) was more reliably effective than CPAP in relieving complex sleep apnea syndrome. While two thirds of participants experienced success with CPAP, approximately 90% experienced success with ASV. Because both methods produced similar symptomatic changes, it is unclear if this polysomnographic effectiveness may translate into other desired outcomes.

CLINICAL TRIALS

Clinicaltrials.Gov NCT00915499.

The emergence of central sleep apnea after surgical relief of nasal obstruction in obstructive sleep apnea

By the current definition, complex sleep apnea (CompSA) refers to the emergence of central sleep apnea (CSA) during the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). However, new-onset CSA has been described with use of other treatments for OSA, including tracheostomy, maxillofacial surgery, and mandibular advancement device. We present a patient with CSA beginning after endoscopic sinus and nasal surgery for nasal obstruction in the setting of mild OSA. This case highlights the importance of non-PAP mechanisms in the pathogenesis of CompSA.

Comparison of two servo ventilator devices in the treatment of complex sleep apnea

OBJECTIVE

Servo ventilation (SV) devices generate positive airway pressure with a variable pressure support that changes in response to a patient's own respiratory output. Two currently available SV devices-VPAP-AdaptSV® and BIPAP-AutoSV®-have been used in treatment of complex sleep apnea (CompSAS), but no side-by-side comparisons are available.

METHODS

Data of 76 consecutive patients with complex sleep apnea, who were prescribed a VPAP-AdaptSV® or BIPAP-AutoSV® in a non-randomized parallel design, were retrospectively analyzed. Patients underwent a diagnostic polysomnogram followed by a continuous positive airway pressure (CPAP) titration and a SV titration study. Objective compliance with the device was assessed at the first visit at 4-6weeks of its use.

RESULTS

Thirty-five patients received a VPAP-AdaptSV® device, while 41 patients were treated with BIPAP-AutoSV®. Patients treated with BIPAP-AutoSV® had a significantly higher apnea-hypopnea index during their CPAP titration study than patients treated with VPAP-AdaptSV® [49/h (28-60) vs. 35/h (19.5-49.5), median (interquartile range), p<0.001]. On follow-up, 56 patients (73.7%) were using their device. Mean nightly use was 5.0h (2.8-6.4) for VPAP-AdaptSV® group and 6.0h (3.5-7.2) for BIPAP-AutoSV® group (p=0.081); an improvement in Epworth Sleepiness Scale score was higher in the BIPAP-AutoSV® group than in the VPAP-AdaptSV® group [4 (1-9) vs. 2.5 (0-5), p=0.02].

CONCLUSION

Our retrospective data indicate that the two servo-ventilation devices are comparable means of controlling complex sleep apnea, and the compliance with them is high.

Eosinophilic pleural effusion complicating allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is primarily a disease of patients with cystic fibrosis or asthma, who typically present with bronchial obstruction, fever, malaise, and expectoration of mucus plugs. We report a case of a young man with a history of asthma who presented with cough, left-sided pleuritic chest pain and was found to have lobar atelectasis and an eosinophilic, empyematous pleural effusion. Bronchoscopy and sputum cultures grew Aspergillus fumigatus, and testing confirmed strong allergic response to this mold, all consistent with a diagnosis of ABPA. This novel and unique presentation of ABPA expands on the differential diagnosis of eosinophilic pleural effusions.

Marked improvement of heart failure upon adequate titration of continuous positive airway pressure in a patient with obstructive sleep apnea

Sleep disordered breathing (SDB) is frequently present in heart failure (HF), and it may take the form of obstructive (OSA) and central (CSA) sleep apnea. The use of continuous positive airway pressure (CPAP) in patients with OSA and HF is associated with an improved neuroendocrine profile and cardiac function. The degree of upper airway obstruction and the airway closing pressure (and the PAP pressure used to relieve it) may all be highly variable in a setting of uncontrolled HF, mostly due to variable airway oedema. We present a case of a man with HF whose cardiac symptoms radically improved after adequate treatment of his OSA with an auto-adjusting PAP device.

Coma with absent brainstem reflexes resulting from zolpidem overdose

Zolpidem is a nonbenzodiazepine hypnotic with a favorable adverse effect profile. There are single reports of respiratory decompensation associated with zolpidem overdose. We report a case ofa young woman with depression who developed deep coma with respiratory failure and a loss of brainstem reflexes as a result of zolpidem overdose. Supportive management led to a complete recovery of neurologic function. Acute zolpidem overdose should be considered in the differential diagnosis of coma with absent brainstem reflexes.

Dysphonia and chest pain as presenting symptoms of pneumomediastinum

Spontaneous pneumomediastinum (SPM) is a rare but generally benign condition characterized by the presence of free air in the mediastinal space that is unrelated to trauma or medical procedure. We describe a case of a 25-year-old woman who presented to the emergency room with a chief complaint of dysphonia, and chest pain. An X-ray of the neck and CT of the chest were performed and showed findings consistent with a pneumomediastinum. Supportive treatment led to an uneventful recovery. We discuss the differential diagnosis of the coexisting chest pain and dysphonia in the diagnosis of SPM.

Pleural effusion associated with pegylated interferon alpha and ribavirin treatment for chronic hepatitis C

Lung toxicity related to interferon (IFN) alpha typically takes a form of interstitial pneumonitis, granulomatous inflammation, or organizing pneumonia. We report a case of a 52-year-old woman, who developed pneumonitis with exudative, lymphocytic-predominant pleural effusion following treatment with pegylated IFN alpha and ribavirin for hepatitis C. Her symptoms and lung findings resolved over 3 months of observation without corticosteroid therapy.

Natural course of complex sleep apnea--a retrospective study

Patients with complex sleep apnea syndrome (CompSAS) have obstructive sleep apnea but develop troublesome central sleep apnea activity or Cheyne-Stokes breathing when provided continuous positive airway pressure (CPAP) therapy. We examined whether CompSAS activity persists with long-term CPAP treatment. We retrospectively identified all patients with CompSAS who underwent two therapeutic polysomnograms (PSGs) separated by at least 1 month during 2003-2005. We compared PSG findings between the initial and follow-up study and noted clinical responses to therapy. We identified 13 CompSAS patients meeting criteria. Most follow-up PSGs were ordered after an abnormal overnight oximetry on CPAP or because of CPAP intolerance after 195 (49-562) days. The residual apnea-hypopnea index (AHI) on CPAP decreased from 26 (23-40) on the first PSG to 7 (3-21.5) on the follow-up PSG. Only seven patients reached AHI < 10 and 6 had AHI > or = 10 ("CPAP nonresponders") at follow-up. "CPAP nonresponders" were sleepier (Epworth Sleepiness Score 13 [12.5-14] vs 9 [6-9.5], p = 0.03) and trended toward lower body mass index (29.7 [28.6-31.6] vs 34.3 [32.5-35.1], p = 0.06). Both groups were equally compliant with CPAP therapy. Although the AHI tends to improve over time in CompSAS patients treated with CPAP, in this retrospective study nearly half-maintained a persistently elevated AHI. A prospective trial is merited to determine the optimal treatment for these patients.

Moving beyond empiric continuous positive airway pressure (CPAP) trials for central sleep apnea: a multi-modality titration study

There is no universally accepted method to determine effective therapy for central sleep apnea (CSA). Continuous positive airway pressure (CPAP) applied acutely most often does not eliminate apneas and hypopneas. We hypothesized that the application of two or more therapeutic modalities after the diagnostic phase of polysomnography, a multi-modality titration study (MMTS), would identify a successful CSA treatment more often than a standard split-night study (SNS) and obviate the need for additional polysomnograms to determine a successful therapy. We retrospectively analyzed polysomnograms of patients diagnosed with CSA at our Sleep Disorders Center. We defined a therapy trial that resulted in an apnea-hypopnea index < 10 with at least one treatment modality as a therapeutic success. One hundred fifteen patients with CSA were studied. Sixty-six patients (57.4%) underwent a SNS, and 49 patients (42.6%) underwent a MMTS. SNS yielded only 8/66 (12.1%) successes on the first night, whereas a MMTS yielded 19/49 (38.8%) successes (p = 0.001, two-tailed Fishers exact). Patients who underwent a SNS eventually had similar rate of success as patients studied with MMTS (60.6 vs 63.3%, NS), but required more testing. Adaptive servo-ventilation was the most successful modality tested, yielding 36/46 (78.3%) successes. Trials of additional modalities following a failed trial of CPAP often produce a successful option that may guide therapy in patients with CSA. This approach may lead to establishing the diagnosis and treatment plans faster, while reducing unnecessary testing.

Use of complementary and alternative medicine treatments by patients with obstructive sleep apnea hypopnea syndrome

STUDY OBJECTIVES

To assess the proportion of patients with obstructive sleep apnea hypopnea syndrome (OSAHS) reporting previous or current use and interest in future use of complementary and alternative medicine (CAM) therapies.

DESIGN

Cross-sectional, point-of-care, anonymous survey.

SETTING

Sleep disorders center at a Midwest tertiary care center.

PARTICIPANTS

Six hundred forty-six consecutive patients undergoing polysomnography.

MEASUREMENTS

The survey instrument comprised 45 items specifically related to CAM therapies, in addition to obtaining baseline data.

RESULTS

Response rate was 81% (522/646). A total of 406/522 (78%) patients were diagnosed with OSAHS. Mean age +/- SD was 57 +/- 14 years, and 267 participants (66%) were men. Overall, 237 (58%) participants reported ever using CAM. Ever and current CAM use specifically for improving sleep was reported by 20% and 7% of the participants, respectively. Twenty-six percent of participants reported ever using biologic products, and 52% reported ever using nonbiologic CAM treatments. A high proportion (58%) of the participants showed interest in future CAM use for improving sleep.

CONCLUSION

A high proportion of patients with OSAHS report previous or current use, and interest in future use, of CAM treatments. This underscores the need to conduct further research in this field.

Multiple skeletal injuries resulting from uncontrolled restless legs syndrome

Restless legs syndrome is a common condition that results in difficulties falling and staying asleep and perception of poor sleep quality. We report a case of a 73-year-old woman with uncontrolled restless legs syndrome who spent most of the night standing and walking. As a result of her nighttime behaviors, she fell several times and sustained, on several separate occasions, fractures of both forearms, ribs, and nose. Iron replacement therapy and changing of her dopamine-agonist medications resulted in almost complete relief of symptoms. Physicians should be aware of the potential for injury in patients with uncontrolled RLS.

Chronic cough from the patient's perspective

OBJECTIVE

To identify the factors that patients consider most concerning about their cough.

PATIENTS AND METHODS

All consecutive patients who presented with a complaint of chronic cough between November 1, 2000, and February 28, 2001, were prospectively surveyed for cough-related complaints using an 18-item symptom-complaint questionnaire. We analyzed frequencies of responses and response patterns to specific items on the questionnaire. We also examined whether the responses to individual items related to the patient's age, sex, and duration of cough.

RESULTS

Of the 146 consecutive patients referred for evaluation of chronic cough, 136 were eligible for inclusion in the study. These patients cited feelings of frustration, irritability, or anger (43%), frequent physician visits and testing (41%), and sleep disturbances (38%) as the most prevalent major problems. The responses to individual items on the questionnaire were not related to patients' age, sex, and cough duration. Anxiety about underlying serious illness continued to be a concern for most patients.

CONCLUSIONS

Frustration, anger, or anxiety was the most frequent major problem cited by patients. Frequent physician visits and testing was the unexpected second most frequent major problem. These findings are important because most chronic cough guidelines are based on clinical efficacy and cost-effectiveness considerations rather than on patient satisfaction. Future studies regarding chronic cough evaluation should take into account patient satisfaction and perceived burden of disease as outcome variables.

Predictors of acute lung injury and severe hypoxemia in patients undergoing operative talc pleurodesis

BACKGROUND

Acute lung injury (ALI) is a life-threatening complication of talc pleurodesis. This study defines characteristics that predispose patients to ALI and severe hypoxemia in patients after video-assisted thoracoscopic surgery (VATS) talc pleurodesis.

METHODS

Charts of patients who underwent talc pleurodesis at Northwestern Memorial Hospital between January 1, 1997 and December 31, 2003 were retrospectively reviewed. We sought variables associated with the development of postoperative ALI or severe hypoxemia, defined as an increase in fraction of the inspired oxygen by more than 0.15 within 24 hours after the surgery. The analysis included 84 patients (58 women, 26 men) who underwent VATS talc pleurodesis for malignant (n = 74) or benign (n = 10) indications.

RESULTS

ALI developed in 5 patients (5.9%), severe hypoxemia developed in 25 (29.8%), and 54 (64.3%) did not have postoperative complications. In multivariate analysis, the presence of peripheral edema before pleurodesis (p = 0.005), any preoperative requirement for supplemental oxygen (p = 0.032), and chemotherapy within 14 days before pleurodesis (p = 0.04) were identified as predictors of ALI or severe postoperative hypoxemia.

CONCLUSIONS

Oxygen supplementation, recent chemotherapy, and presence of peripheral edema were independent predictors of a combined outcome of ALI or severe hypoxemia after VATS talc pleurodesis. Patients with these characteristics might be at risk for adverse outcomes of talc pleurodesis and should be considered for alternative therapy for their effusions.

Cerebrospinal Fluid Leak and Meningitis Associated With Nasal Continuous Positive Airway Pressure Therapy

Clear rhinorrhea is a common symptom in patients with obstructive sleep apnea (OSA) and may worsen with continuous positive airway pressure therapy. Clear rhinorrhea can also be the presenting symptom of cerebrospinal fluid (CSF) leak, which is evidence of a communication between the subarachnoid space and the nasal cavity or sinuses. While CSF leak has been reported to occur with nasal continuous positive airway pressure (nCPAP) therapy following trauma to the skull base, its association with OSA and nCPAP therapy in the absence of trauma has not been previously described. We report two patients with OSA in whom CSF leak developed following the institution of nCPAP therapy. In one patient, the rhinorrhea was complicated by meningitis. Both patients underwent successful repair of their defects. One patient successfully restarted nCPAP therapy, while the other refused it.