Charles W. Atwood

Noninferiority of functional outcome in ambulatory management of obstructive sleep apnea.

RATIONALE Home portable monitor testing is increasingly being used to diagnose patients with obstructive sleep apnea (OSA) and to initiate them on continuous positive airway pressure (CPAP) treatment. OBJECTIVES To compare functional outcome and treatment adherence in patients who receive ambulatory versus in-laboratory testing for OSA. METHODS Veterans with suspected OSA were randomized to either home testing or standard in-laboratory testing. Home testing consisted of a type 3 portable monitor recording followed by at least three nights using an automatically adjusting positive airway pressure apparatus. Participants diagnosed with OSA were treated with CPAP for 3 months. MEASUREMENTS AND MAIN RESULTS We measured the change in Functional Outcomes of Sleep Questionnaire score, with an a priori noninferiority delta of -1, and the mean daily hours of objectively measured CPAP adherence, with an a priori noninferiority delta of -0.75 hour/day. Of the 296 subjects enrolled, 260 (88%) were diagnosed with OSA, and 213 (75%) were initiated on CPAP. Mean ± SD functional outcome score improved 1.74 ± 2.81 in the home group (P < 0.001) and 1.85 ± 2.46 in the in-laboratory group (P < 0.0001). The lower bound of the one-sided 95% noninferiority confidence interval was -0.54. Mean ± SD hours of daily CPAP adherence were 3.5 ± 2.5 hours/day in the home group and 2.9 ± 2.3 hours/day in the in-laboratory group (P = 0.08). The lower bound of the one-sided 95% noninferiority confidence interval was 0.03. CONCLUSIONS Functional outcome and treatment adherence in patients evaluated according to a home testing algorithm is not clinically inferior to that in patients receiving standard in-laboratory polysomnography.

The coordination of breathing and swallowing in chronic obstructive pulmonary disease.

RATIONALE During deglutition, a strongly preferred exhale-swallow-exhale pattern has been shown in healthy adults. Disruption of this pattern can provoke prandial aspiration. Impaired coordination of breathing and swallowing has been measured in patients with chronic obstructive pulmonary disease (COPD) during the exacerbated state, but no reports describe the coordination of breathing and swallowing in stable patients with COPD during oral intake. OBJECTIVES To test the hypothesis that persons with moderate to severe COPD would show disordered coordination of breathing and swallowing during oral intake when compared with a matched, healthy control group. METHODS This study used a prospective, repeated measures design using 25 subjects with COPD and 25 control subjects. Respiratory inductance plethysmography and nasal thermistry were used simultaneously to track respiratory signals. Submental surface EMG was used to mark the presence of each swallow within the respiratory cycle. Data were recorded while participants randomly and spontaneously swallowed solids and semi-solids. MEASUREMENTS AND MAIN RESULTS Logistic regression showed that participants with COPD swallowed solid food during inhalation more frequently than normal subjects (P = 0.002) and had a significantly higher rate of inhaling after swallowing semi-solid material (P < 0.001). Subjects with COPD also swallowed pudding at low Vt significantly more often than they did the cookie (P = 0.006). Conversely, the control subjects swallowed cookie at low Vt significantly more often than pudding (P = 0.034). Significant differences in deglutitive apnea durations were also found. CONCLUSIONS Patients with COPD exhibit disrupted coordination of the respiratory cycle with deglutition. Disrupted breathing-swallowing coordination could increase the risk of aspiration in patients with advanced COPD and may contribute to exacerbations.

The Coordination of Breathing and Swallowing in Parkinson’s Disease

Multiple investigations have determined that healthy adults swallow most often during exhalation and that exhalation regularly follows the swallow, even when a swallow occurs during inhalation. We hypothesized that persons with idiopathic Parkinson’s disease would demonstrate impaired breathing and swallowing coordination during spontaneous eating. Twenty-five healthy volunteers and 25 Parkinson’s disease patients spontaneously swallowed calibrated pudding and cookie portions while simultaneous nasal airflow and respiratory inductance plethysmography were used to track spontaneous breathing. Surface EMG was used to record the timing of each swallow within the respiratory cycle. When compared to the healthy control group, those with Parkinson’s disease swallowed significantly more often during inhalation and at low tidal volumes. The Parkinson’s participants also exhibited significantly more postswallow inhalation for both consistencies. Only the healthy subjects exhibited significantly longer deglutitive apnea when swallows that occurred during inhalation were compared with those that occurred during exhalation. The high incidence of oropharyngeal dysphagia and risk of aspiration pneumonia found in Parkinson’s disease patients may be partially attributable to impaired coordination of breathing and swallowing.

POSITIVE PRESSURE THERAPY

Positive airway pressure in the treatment of obstructive sleep-disordered breathing (OSDB) is reviewed. Continuous positive airway pressure (CPAP), bilevel positive airway pressure, and variable (auto-CPAP) pressure, their mechanisms of action, benefits, and complications are examined. A perspective on the future of positive airway pressure therapy for OSDB is provided.

Evaluation of a Single-Channel Portable Monitor for the Diagnosis of Obstructive Sleep Apnea

STUDY OBJECTIVE To validate the ApneaLINK (AL) as an accurate tool for determining the presence of obstructive sleep apnea (OSA) in an at-risk sleep clinic population in a home test environment. METHODS Consecutive participants referred with the suspicion of OSA were evaluated in the home with the AL portable monitor (AL Home), followed by simultaneous data collection with diagnostic polysomnography (PSG) and AL in the sleep laboratory (AL Lab). Prevalence, sensitivity, specificity, and ROC curves were calculated for PSG vs. AL Lab, PSG vs. AL Home, and AL Lab vs. AL Home test. Pearson correlations and Bland-Altman plots were constructed. RESULTS Fifty-three (55% female) participants completed the entire study. The mean age of the population was 45.1 ± 11.3 years, and body mass index was 35.9 ± 9.1 kg/m(2). The prevalence of an apnea hypopnea index (AHI) ≥ 15 in the cohort was 35.9%. The results demonstrated a high sensitivity and specificity of the AL respiratory disturbance index (RDI-AL) compared with the AHI from the PSG. The AL Lab had the highest sensitivity and specificity at RDI-AL values ≥ 20 events/h (sensitivity 100%, specificity 92.5%). The AL Home was most sensitive and specific at an RDI-AL ≥ 20 events/h (sensitivity 76.9%, specificity 92.5%). The Pearson correlations for PSG vs. AL Lab and PSG vs. AL Home were ρ = 0.88 and ρ = 0.82, respectively. The Bland-Altman Plots demonstrated good agreement between the methodologies. CONCLUSION The AL home test is an accurate alternative to PSG in sleep clinic populations at risk for moderate and severe OSA. TRIAL REGISTRATION clinicaltrials.gov ID: NCT00354614.

Feasibility of Automated Detection of Advanced Sleep Disordered Breathing Utilizing an Implantable Pacemaker Ventilation Sensor

Objectives: This study tested the feasibility of automatically detecting advanced sleep disordered breathing (SDB) from a pacemaker trans‐thoracic impedance sensor.

Assessment of obstructive sleep apnea in adults undergoing bariatric surgery in the longitudinal assessment of bariatric surgery-2 (LABS-2) study.

STUDY OBJECTIVES Evaluate frequency of diagnostic testing for obstructive sleep apnea (OSA), prevalence of OSA, and factors independently associated with OSA status in adults undergoing bariatric surgery. DESIGN, SETTINGS AND INTERVENTIONS: Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) is an observational cohort of 2,458 adults undergoing bariatric surgery at 10 U.S. hospitals. Within 30 days prior to surgery, researchers determined if participants had a diagnostic polysomnography (PSG) in the previous 12 months. When available, apnea-hypopnea index (AHI) was recorded. Based on medical records and participant report, research clinicians recorded OSA status and positive airway pressure (PAP) use. Participants completed the Berlin Questionnaire (BQ). Multivariable logistic regression was used to determine factors independently associated with AHI-confirmed OSA status. RESULTS 28.7% (n = 693) of participants had a PSG within 12 months before surgery. Of subjects with AHI available (n = 509), 80.7% (n = 411) had OSA (AHI ≥ 5); 83.0% (n = 341) reported PAP use. In participants without a known AHI (n = 1,949), 45.4% (n = 884) had self-reported OSA; 81.2% (n = 718) reported PAP use. Self-reported history of snoring and pauses in breathing (odds ratio [OR] = 10.0; 95%, confidence interval [CI] = 4.8-20.6), male sex (OR = 5.1; 95% CI = 1.7-15.3), older age (OR = 1.4; 95% CI = 1.2-1.6 per 5 years), and larger sagittal abdominal diameter (OR = 1.8; 95% CI = 1.2-2.5 per 5 cm) were independently associated with a greater odds of confirmed OSA. CONCLUSIONS Preoperative diagnostic testing for OSA was infrequent. Prevalence estimates of OSA differed greatly between those with and without a past-year AHI (81% vs. 46%, respectively). Most BQ responses did not differentiate OSA status, but endorsement of snoring and pauses in breathing was independently associated with presence of OSA.

A pilot study of CPAP adherence promotion by peer buddies with sleep apnea.

STUDY OBJECTIVES To evaluate patient ratings of the acceptability of a peer buddy system (PBS). To promote continuous positive airway pressure (CPAP) therapy adherence in patients with obstructive sleep apnea (OSA). To obtain preliminary data on the effectiveness of PBS on sleep-specific health-related quality of life and CPAP adherence. DESIGN Prospective, randomized, and controlled study. SETTING Academic Center. PARTICIPANTS Thirty-nine patients with OSA and 13 patients with OSA who were experienced CPAP users. INTERVENTIONS Recently diagnosed patients with OSA were randomly assigned to either the PBS to promote CPAP adherence (intervention group) or usual care (control group). MEASUREMENTS Patient satisfaction, Functional Outcomes of Sleep Questionnaire (FOSQ), CPAP adherence, vigilance, self-efficacy, and patient activation were measured. RESULTS Ninety-one percent of the subjects rated the PBS as very satisfactory (68%) or satisfactory (23%). During the 90 days of therapy, weekly CPAP adherence was greater in the intervention than the usual care group (MANOVA; F = 2.29; p = 0.04). Patient satisfaction was positively correlated with CPAP adherence (R(2) = 0.14; p = 0.02). We did not find any group differences for FOSQ, vigilance, self-efficacy, or patient activation in this pilot study. CONCLUSION Our pilot study suggests that the PBS intervention is feasible and received high patient satisfaction ratings. CPAP adherence may be improved by peer-driven intervention, but a larger, adequately powered study is needed. CLINICAL TRIAL INFORMATION ClinicalTrials.gov identifier: NCT01164683. COMMENTARY A commentary on this article appears in this issue on page 551. CITATION Parthasarathy S; Wendel C; Haynes PL; Atwood C; Kuna S. A pilot study of CPAP adherence promotion by peer buddies with sleep apnea. J Clin Sleep Med 2013;9(6):543-550.

Nocturia in sleep disordered breathing

Nocturia is an often-described symptom associated with sleep disordered breathing (SDB). Among others, Ulfberg et al. reported nocturia associated with obstructive sleep apnea syndrome (OSAS), and subsequent successful treatment of both entities with continuous positive airway pressure (CPAP) [1]. Multiple de®nitions of nocturia have been proposed, including: (1) awakening from sleep to urinate [2], (2) more than two awakenings per night for urination [3,4] and (3) voided urine volume during hours of sleep in excess of 35% of the 24 h urine output [5]. Complicating the lack of a standard de®nition of nocturia, are the absence of scienti®cally derived normative values for the frequency of awakenings to urinate or for the volume of urine voided per night. Several investigators have suggested that one event per night is within normal limits and the ratio between daytime (8 AM±8 PM) and nighttime (8 PM±8 AM) urination is 2:1 in young adults [6,7], while two or more awakenings from sleep to urinate per night is considered abnormal [8]. In this report we will discuss the consequences, prevalence, pathophysiology and therapy of nocturia in SDB.

Periodic limb movement disorder: an unusual mechanism of twiddling and potential benefit from cardiac resynchronization therapy.

Dislodgement of an LV lead is attributed to periodic limb movement disorder. Resynchronization therapy improves CHF and symptoms of periodic limb movement disorder. Potential interaction of disordered sleep and CHF in this case is briefly reviewed.