Depicting and defining sleep disturbed breathing associated with vagal nerve stimulation.

BACKGROUND: Vagal nerve stimulators (VNS), which have been approved for management of refractory epilepsy and depression, induce unique disturbances of breathing during sleep (SDBVNS) that are not captured well using standard criteria. The primary purpose of this retrospective study was to compare AASM definitions with alternative criteria to more accurately measure SDBVNS We also sought to assess outcome variables that may be clinically relevant and response to positive airway pressure therapy. METHODS: We analyzed the electronic medical records and comprehensive polysomnography results of all adult subjects with active VNS for epilepsy who were referred to the sleep center for suspected sleep apnea (2015-2020). We compared standard AASM criteria for defining apneas/hypopnea index (AHIAASM) with three novel scoring criteria for hypopnea according to degree of oxygen desaturation associated with VNS events: AHIVNS0 (none required); AHIVNS2 (2% required); and AHIVNS3 (3% required). RESULTS: Twenty-six subjects were included in the final analysis with 35 PSGs (14 females/12 males). The mean age was 33.6 years and mean body mass index (BMI) of 32.2 kg/m2. AHIAASM measured ≥ 15/hour in 7 (26.9%) subjects versus 21 (80.8%) by AHIVNS0; 15 (70.0%) by AHIVNS2; and 5 (19.2%) by AHIVNS3. Clinically significant hypoxemia was not present. The mean time SpO2<89% was 7 (20.8) minutes. Oximetry tracings often showed a desaturation pattern that resembled a sawfish rather than sawtooth. Arousals specifically linked to VNS activation were not elevated (2.9/hour). The baseline AHIVNS0 was 27.7/hour with a lowest AHIVNS0 on PAP of 27.9/hr. CONCLUSIONS: AASM scoring criteria significantly underestimated the degree of VNS induced respiratory disturbances. VNS events were not associated with increased arousals or significant hypoxemia. PAP therapy was an ineffective treatment in this population. This study adds to the increasing body of evidence of sleep disordered breathing related to VNS and questions the clinical significance of this finding.

An Automated Algorithm Incorporating Poincaré Analysis Can Quantify the Severity of Opioid-Induced Ataxic Breathing.

BACKGROUND: Opioid-induced respiratory depression (OIRD) is traditionally recognized by assessment of respiratory rate, arterial oxygen saturation, end-tidal CO2, and mental status. Although an irregular or ataxic breathing pattern is widely recognized as a manifestation of opioid effects, there is no standardized method for assessing ataxic breathing severity. The purpose of this study was to explore using a machine-learning algorithm for quantifying the severity of opioid-induced ataxic breathing. We hypothesized that domain experts would have high interrater agreement with each other and that a machine-learning algorithm would have high interrater agreement with the domain experts for ataxic breathing severity assessment. METHODS: We administered target-controlled infusions of propofol and remifentanil to 26 healthy volunteers to simulate light sleep and OIRD. Respiration data were collected from respiratory inductance plethysmography (RIP) bands and an intranasal pressure transducer. Three domain experts quantified the severity of ataxic breathing in accordance with a visual scoring template. The Krippendorff alpha, which reports the extent of interrater agreement among N raters, was used to assess agreement among the 3 domain experts. A multiclass support vector machine (SVM) was trained on a subset of the domain expert-labeled data and then used to quantify ataxic breathing severity on the remaining data. The Vanbelle kappa was used to assess the interrater agreement of the machine-learning algorithm with the grouped domain experts. The Vanbelle kappa expands on the Krippendorff alpha by isolating a single rater-in this case, the machine-learning algorithm-and comparing it to a group of raters. Acceptance criteria for both statistical measures were set at >0.8. The SVM was trained and tested using 2 sensor inputs for the breath marks: RIP and intranasal pressure. RESULTS: Krippendorff alpha was 0.93 (95% confidence interval [CI], 0.91-0.95) for the 3 domain experts. Vanbelle kappa was 0.98 (95% CI, 0.96-0.99) for the RIP SVM and 0.96 (0.92-0.98) for the intranasal pressure SVM compared to the domain experts. CONCLUSIONS: We concluded it may be feasible for a machine-learning algorithm to quantify ataxic breathing severity in a manner consistent with a panel of domain experts. This methodology may be helpful in conjunction with traditional measures to identify patients experiencing OIRD.

Chronic opioid use and central sleep apnea: a review of the prevalence, mechanisms, and perioperative considerations.

BACKGROUND: Chronic opioid use has been associated with the development of sleep-disordered breathing (SDB) such as central sleep apnea (CSA). Patients receiving chronic opioids may suffer from unrecognized sleep apnea that contributes to opioid-overdose death. Currently, information regarding the perioperative management of patients with chronic opioid-associated CSA is limited. The objectives of this review are to define the clinical manifestations of SDB associated with chronic opioid therapy, especially CSA, and to highlight their prevalence, mechanisms, risk factors, and perioperative management. METHODS: We searched Medline (1983-2014), Medline In-Process and other nonindexed citations (July 2014), EMBASE (1983-2014), the Cochrane Database of Systematic Reviews (January 2005-2014), the Cochrane Central Registry of Controlled Trials (July 2014), and PubMed basic search for new materials (1983-2014). Anesthesia and Sleep Medicine meeting abstracts were also searched for relevant articles. We included all prospective, retrospective studies and case reports in which CSA and chronic opioid use was confirmed by polysomnography. CSA was defined as the absence of airflow for ≥ 10 seconds with the absence of breathing efforts. A Central Apnea Index ≥ 5 events/h was considered significant. RESULTS: The search strategy yielded 8 studies which included 560 patients. The overall prevalence of CSA in patients taking chronic opioids was high (24%). The morphine equivalent daily dose (MEDD) was strongly associated with the severity of the SDB, predominantly CSA, with an MEDD of >200 mg being a threshold of particular concern. Concurrent use of benzodiazepines or hypnotics was associated with the severity of CSA in one study. Body mass index was inversely related to the severity of SDB. There were various recommendations regarding the best type of positive airway pressure therapy for the treatment of opioid-associated CSA. Continuous positive airway pressure may be ineffective in eliminating, or may even increase, CSA. Adaptive servoventilation and bilevel positive airway pressure ventilation were effective according to some reports. CONCLUSIONS: The overall prevalence of CSA in patients taking chronic opioids was 24%. The most important risk factors for severity of CSA were an MEDD >200 mg, and low or normal body mass index. Continuous positive airway pressure is often ineffective for treating CSA. Limited data are available on the perioperative management of patients with CSA associated with chronic opioid use. Further prospective studies on the perioperative risks and management of these patients are needed.

REM sleep behavior disorder in Parkinson's disease: A case from India confirmed with polysomnographic data.

Rapid eye movement (REM) sleep behavior disorder is a condition characterized by dream enactment. This condition may accompany neurodegenerative disorders. However, only a few reports from India are available, that too, without any polysomnographic evidence. We are reporting a case of REM sleep behavior disorder with polysomnographic evidence.

Early detection of hospitalized patients with previously diagnosed obstructive sleep apnea using computer decision support alerts.

Obstructive sleep apnea (OSA) is a worldwide problem affecting 2-14% of the general population and most patients remain undiagnosed. OSA patients are at elevated risk for hypoxemia, cardiac arrhythmias, cardiorespiratory arrest, hypoxic encephalopathy, stroke and death during hospitalization. Clinical screening questionnaires are used to identify hospitalized patients with OSA; especially before surgery. However, current screening questionnaires miss a significant number of patients and require more definitive testing before specific therapy can be started. Moreover, many patients are admitted to the hospital with a previous diagnosis of OSA that is not reported. Thus, many patients with OSA do not receive appropriate therapy during hospitalization due to the lack of information from previous inpatient and outpatient encounters. Large enterprise data warehouses provide the ability to monitor patient encounters over wide geographical areas. This study found that previously diagnosed OSA is highly prevalent and undertreated in hospitalized patients and the use of early computer alerts by respiratory therapists resulted in significantly more OSA patients receiving appropriate medical care (P < 0.002) which resulted in significantly fewer experiencing hypoxemia (P < 0.006). The impact was greater for non-surgery patients compared to surgery patients.

Sleep disordered breathing in patients receiving therapy with buprenorphine/naloxone.

Patients using chronic opioids are at risk for exceptionally complex and potentially lethal disorders of breathing during sleep, including central and obstructive apnoeas, hypopnoeas, ataxic breathing and nonapnoeic hypoxaemia. Buprenorphine, a partial µ-opioid agonist with limited respiratory toxicity, is widely used for the treatment of opioid dependency and chronic nonmalignant pain. However, its potential for causing sleep disordered breathing has not been studied. 70 consecutive patients admitted for therapy with buprenorphine/naloxone were routinely evaluated with sleep medicine consultation and attended polysomnography. The majority of patients were young (mean±sd age 31.8±12.3 years), nonobese (mean±sd body mass index 24.9±5.9 kg·m(-2)) and female (60%). Based upon the apnoea/hypopnoea index (AHI), at least mild sleep disordered breathing (AHI ≥5 events·h(-1)) was present in 63% of the group. Moderate (AHI ≥15- <30 events·h(-1)) and severe (AHI ≥30 events·h(-1)) sleep apnoea was present in 16% and 17%, respectively. Hypoxaemia, defined as an arterial oxygen saturation measured by pulse oximetry, of <90% for ≥10% of sleep time, was present in 27 (38.6%) patients. Despite the putative protective ceiling effect regarding ventilatory suppression observed during wakefulness, buprenorphine may induce significant alterations of breathing during sleep at routine therapeutic doses.

The STOP-Bang equivalent model and prediction of severity of obstructive sleep apnea: relation to polysomnographic measurements of the apnea/hypopnea index.

BACKGROUND: Various models and questionnaires have been developed for screening specific populations for obstructive sleep apnea (OSA) as defined by the apnea/hypopnea index (AHI); however, almost every method is based upon dichotomizing a population, and none function ideally. We evaluated the possibility of using the STOP-Bang model (SBM) to classify severity of OSA into 4 categories ranging from none to severe. METHODS: Anthropomorphic data and the presence of snoring, tiredness/sleepiness, observed apneas, and hypertension were collected from 1426 patients who underwent diagnostic polysomnography. Questionnaire data for each patient was converted to the STOP-Bang equivalent with an ordinal rating of 0 to 8. Proportional odds logistic regression analysis was conducted to predict severity of sleep apnea based upon the AHI: none (AHI < 5/h), mild (AHI ≥ 5 to < 15/h), moderate (≥ 15 to < 30/h), and severe (AHI ≥ 30/h). RESULTS: Linear, curvilinear, and weighted models (R(2) = 0.245, 0.251, and 0.269, respectively) were developed that predicted AHI severity. The linear model showed a progressive increase in the probability of severe (4.4% to 81.9%) and progressive decrease in the probability of none (52.5% to 1.1%). The probability of mild or moderate OSA initially increased from 32.9% and 10.3% respectively (SBM score 0) to 39.3% (SBM score 2) and 31.8% (SBM score 4), after which there was a progressive decrease in probabilities as more patients fell into the severe category. CONCLUSIONS: The STOP-Bang model may be useful to categorize OSA severity, triage patients for diagnostic evaluation or exclude from harm.

NREM sleep parasomnia associated with Chiari I malformation.

Parasomnias are common sleep disorders in children, and most cases resolve naturally by adolescence.(1) They represent arousal disorders beginning in NREM sleep and are generally non-concerning in children. The diagnosis can usually be made by clinical assessment, and testing with polysomnography is not routinely indicated.(2) However, in certain cases with atypical features, polysomnography and more extensive neurologic evaluation are medically indicated.

Favorable changes in cardiac geometry and function following gastric bypass surgery: 2-year follow-up in the Utah obesity study.

OBJECTIVES: The objective of this study was to test the hypothesis that gastric bypass surgery (GBS) would favorably impact cardiac remodeling and function. BACKGROUND: GBS is increasingly used to treat severe obesity, but there are limited outcome data. METHODS: We prospectively studied 423 severely obese patients undergoing GBS and a reference group of severely obese subjects that did not have surgery (n = 733). RESULTS: At a 2-year follow up, GBS subjects had a large reduction in body mass index compared with the reference group (-15.4 ± 7.2 kg/m(2) vs. -0.03 ± 4.0 kg/m(2); p < 0.0001), as well as significant reductions in waist circumference, systolic blood pressure, heart rate, triglycerides, low-density lipoprotein cholesterol, and insulin resistance. High-density lipoprotein cholesterol increased. The GBS group had reductions in left ventricular (LV) mass index and right ventricular (RV) cavity area. Left atrial volume did not change in GBS but increased in reference subjects. In conjunction with reduced chamber sizes, GBS subjects also had increased LV midwall fractional shortening and RV fractional area change. In multivariable analysis, age, change in body mass index, severity of nocturnal hypoxemia, E/E', and sex were independently associated with LV mass index, whereas surgical status, change in waist circumference, and change in insulin resistance were not. CONCLUSIONS: Marked weight loss in patients undergoing GBS was associated with reverse cardiac remodeling and improved LV and RV function. These data support the use of bariatric surgery to prevent cardiovascular complications in severe obesity.

Health outcomes of gastric bypass patients compared to nonsurgical, nonintervened severely obese.

Favorable health outcomes at 2 years postbariatric surgery have been reported. With exception of the Swedish Obesity Subjects (SOS) study, these studies have been surgical case series, comparison of surgery types, or surgery patients compared to subjects enrolled in planned nonsurgical intervention. This study measured gastric bypass effectiveness when compared to two separate severely obese groups not participating in designed weight-loss intervention. Three groups of severely obese subjects (N = 1,156, BMI >or= 35 kg/m(2)) were studied: gastric bypass subjects (n = 420), subjects seeking gastric bypass but did not have surgery (n = 415), and population-based subjects not seeking surgery (n = 321). Participants were studied at baseline and 2 years. Quantitative outcome measures as well as prevalence, incidence, and resolution rates of categorical health outcome variables were determined. All quantitative variables (BMI, blood pressure, lipids, diabetes-related variables, resting metabolic rate (RMR), sleep apnea, and health-related quality of life) improved significantly in the gastric bypass group compared with each comparative group (all P < 0.0001, except for diastolic blood pressure and the short form (SF-36) health survey mental component score at P < 0.01). Diabetes, dyslipidemia, and hypertension resolved much more frequently in the gastric bypass group than in the comparative groups (all P < 0.001). In the surgical group, beneficial changes of almost all quantitative variables correlated significantly with the decrease in BMI. We conclude that Roux-en-Y gastric bypass surgery when compared to severely obese groups not enrolled in planned weight-loss intervention was highly effective for weight loss, improved health-related quality of life, and resolution of major obesity-associated complications measured at 2 years.

Are opioids associated with sleep apnea? A review of the evidence.

Chronic opioid use for nonmalignant pain has increased dramatically; nonillicit unintentional deaths have also increased. This article reviews the physiology of breathing, effects of sleep on respiration, effects of opioids on respiration, potential interactions between sleep and opioids on respiration, and current evidence that chronic opioid use is associated with sleep-disordered breathing.

Adaptive servoventilation (ASV) in patients with sleep disordered breathing associated with chronic opioid medications for non-malignant pain.

BACKGROUND: Adaptive servoventilation (ASV) can be effective therapy for specific types of central apnea such as Cheyne-Stokes respiration (CSR). Patients treated chronically with opioids develop central apneas and ataxic breathing patterns (Biot's respiration), but therapy with CPAP is usually unsuccessful. There are no published studies of ASV in patients with sleep apnea complicated by chronic opioid therapy. METHODS: Retrospective analysis of 22 consecutive patients referred for evaluation and treatment of sleep apnea who had been using opioid medications for at least 6 months, had an apnea-hypopnea index (AHI) > or = 20/h, and had been tested with ASV. Baseline polysomnography was compared with CPAP and ASV. OUTCOME VARIABLES: AHI, central apnea index (CAI), obstructive apnea index (OAI), hypopnea index (HI), desaturation index, mean SpO2, lowest SpO2, time SpO2 < 90%, and degree of Biot's respiration. RESULTS: Mean (SD) AHI measured 66.6/h (37.3) at baseline, 70.1/h (32.6) on CPAP, and 54.2/h (33.0) on ASV. With ASV, the mean OAI was significantly decreased to 2.4/h (p < 0.0001), and the mean HI increased significantly to 35.7/h (p < 0.0001). The decrease of CAI from 26.4/h to 15.6/h was not significant (p = 0.127). Biot's breathing persisted, and oxygenation parameters were unimproved with ASV. CONCLUSIONS: Due to residual respiratory events and hypoxemia, ASV was considered insufficient therapy in these patients. Persistence of obstructive events could be due to suboptimal pressure settings (end expiratory and/or maximal inspiratory). Residual central events could be related to fundamental differences in the pathophysiology of CSR compared to opioid induced breathing disturbances.

Chronic opioid use is a risk factor for the development of central sleep apnea and ataxic breathing.

BACKGROUND: Chronic opioid therapy for pain management has increased dramatically without adequate study of potential deleterious effects on breathing during sleep. METHODS: A retrospective cohort study comparing 60 patients taking chronic opioids matched for age, sex, and body mass index with 60 patients not taking opioids was conducted to determine the effect of morphine dose equivalent on breathing patterns during sleep. RESULTS: The apnea-hypopnea index was greater in the opioid group (43.5/h vs 30.2/h, p < .05) due to increased central apneas (12.8/h vs 2.1/h; p < .001). Arterial oxygen saturation (SpO2) in the opioid group was significantly lower during both wakefulness (difference 2.1%, p < .001) and non-rapid eye movement (NREM) sleep (difference 2.2%, p < .001) but not during rapid eye movement (REM) sleep (difference 1.2%) than in the nonopioid group. Within the opioid group, and after controlling for body mass index, age, and sex, there was a dose-response relationship between morphine dose equivalent and apnea-hypopnea (p < .001), obstructive apnea (p < .001), hypopnea (p < .001), and central apnea indexes (p < .001). Body mass index was inversely related to apnea-hypopnea index severity in the opioid group. Ataxic or irregular breathing during NREM sleep was also more prevalent in patients who chronically used opioids (70% vs 5.0%, p < .001) and more frequent (92%) at a morphine dose equivalent of 200 mg or higher (odds ratio = 15.4, p = .017). CONCLUSIONS: There is a dose-dependent relationship between chronic opioid use and the development of a peculiar pattern of respiration consisting of central sleep apneas and ataxic breathing. Although potentially significant, the clinical relevance of these observations remains to be established.

Left ventricular hypertrophy in severe obesity: interactions among blood pressure, nocturnal hypoxemia, and body mass.

Obese subjects have a high prevalence of left ventricular (LV) hypertrophy. It is unclear to what extent LV hypertrophy results directly from obesity or from associated conditions, such as hypertension, impaired glucose homeostasis, or obstructive sleep apnea. We tested the hypothesis that LV hypertrophy in severe obesity is associated with additive effects from each of the major comorbidities. Echocardiography and laboratory testing were performed in 455 severely obese subjects with body mass index 35 to 92 kg/m(2) and 59 nonobese reference subjects. LV hypertrophy, defined by allometrically corrected (LV mass/height(2.7)), gender-specific criteria, was present in 78% of the obese subjects. Multivariable regression analyses showed that average nocturnal oxygen saturation <85% was the strongest independent predictor of LV hypertrophy (P<0.001), followed by systolic blood pressure (P<0.015) and then body mass index (P<0.05). With regard to LV mass, there were synergistic effects between hypertension and body mass index (P interaction <0.001) and between hypertension and reduced nocturnal oxygen saturation. Severely obese subjects had normal LV endocardial fractional shortening (35+/-6% versus 35+/-6%) but mildly decreased midwall fractional shortening (15+/-2% versus 17+/-2%; P<0.001), indicating subtle myocardial dysfunction. In conclusion, more severe nocturnal hypoxemia, increasing systolic blood pressure, and body mass index are all independently associated with increased LV mass. The effects of increased blood pressure seem to amplify those of sleep apnea and more severe obesity.

Polysomnography in hospitalized patients using a wireless wide area network.

BACKGROUND: Sleep-disordered breathing and hypoxemia frequently underlie many common medical conditions for which patients require hospitalization. Sleep apnea is associated with adverse cardiovascular, neurovascular, inflammatory, and metabolic consequences, many of which can be reversed with nasal continuous positive airway pressure. Although polysomnography is the gold standard for outpatient evaluation of sleep apnea, it has not been used for establishing the diagnosis or as a means to intervene with evidence-based therapy in the hospital setting. SETTING: A 468-bed tertiary-care facility for adults in which an 801.11b wireless network supplements a typical hardwired local area network. METHODOLOGY: We developed a technique to perform 16-channel polysomnography on any patient in any location in the hospital without interfering with routine nursing care. Qualified sleep technicians are able to remotely adjust electrophysiologic and respiratory parameters, as well as control continuous positive airway pressure titration. The study can also be monitored from any location with Internet access using a HIPAA-compliant virtual private network. RESULTS: Polysomnography was performed on 51 inpatients (age 26 to 89 years; 31 men). Mean (SD) body mass index measured 34.1 kg/m(2) (12.4). Cardiac disease (47%) and neurologic disease (27%) were the most frequent primary indications for admission. Data acquisition was not disrupted due to connectivity problems. The most frequent deficiencies were reduced sleep time (range 0.8-6.5 hours; mean [SD] 3.3 hours [1.6]) and reduced or absent rapid eye movement sleep. Mean (SD) apnea-hypopnea index measured 35.9 events per hour of sleep (SD 26.3) and 19.4 events per hour of total recording time (SD 17.5). CONCLUSIONS: Polysomnography measurements transmitted across a wireless wide area network increases the capacity of the traditional hospital-based sleep laboratory. This technique can facilitate early implementation of appropriate therapy and may reverse underlying factors associated with the primary cause of hospitalization. Indications and standards of practice need to be specifically established for inpatient polysomnography.

Design and rationale of the Utah obesity study. A study to assess morbidity following gastric bypass surgery.

PURPOSE: This paper details the design and baseline characteristics of a study on the morbidity associated with Roux-en-Y gastric bypass surgery (GBP) in severely obese adults. This study is designed to assess the effectiveness of GBP in reducing morbidity and maintaining weight loss. A wide array of clinical tests and psycho-behavioral questionnaires are included as part of the study. METHODS: Three groups (n=1156 severely obese) have been recruited for this study: cases who were approved for and participated in surgery (n=415), a control group of GBP seeking individuals who were denied surgery (n=420) and a control group that was randomly chosen from a population of severely obese participants who were not seeking GBP (n=321). Clinical measures include: a physician interview and detailed medical history, resting electro- and echocardiograms, a submaximal exercise treadmill test and electrocardiogram, pulmonary function, limited polysomnography, resting metabolic rate, anthropometrics, resting and exercise blood pressure, comprehensive blood chemistry and urinalysis and dietary, quality of life and physical activity questionnaires. Most participants (76%) were tested following an overnight stay in a clinical research center. Remaining participants underwent less extensive testing in an outpatient clinic. RESULTS: Baseline characteristics of the 1156 participants are available for selected measures. Mean+/-S.D. for BMI was 46+/-7.5 kg/m(2) (range=33 to 92) and for age was 44+/-11.4 years (range=18 to 72). The prevalence of diabetes and hypertension was 19% and 35%, respectively. Of the participants who had an echocardiogram or polysomnogram, 92% had left-ventricular hypertrophy and 85% had mild to severe sleep apnea. The two control groups were similar to the surgical group. At approximately 24 months, all participants will have a second clinical examination. Statistical comparisons of changes in morbidity variables will be made between the surgical and control groups. CONCLUSIONS: This study design facilitates assessment of risks and benefits of GBP to perform recommendations on whether or not to perform surgery on the severely obese patient. Baseline and 2-year exams provide valuable data for comparison to future long-term follow-up data that can be collected at 5 and 10 years.

Simultaneous use of antidepressant and antihypertensive medications increases likelihood of diagnosis of obstructive sleep apnea syndrome.

BACKGROUND: Essential hypertension and symptoms of depression such as unexplained fatigue and tiredness are frequently encountered in primary medical care clinics. Although, exhaustive evaluation rarely detects unsuspected underlying disorders, obstructive sleep apnea (OSA) is commonly associated with each of these conditions. We tested the hypothesis that therapy with antihypertensive and antidepressant medications predicts the increased likelihood of OSA. METHODS: We analyzed the computer archive of 212,972 patients for prescriptions for antihypertensive medications, antidepressant medications, and International Classification of Diseases, Ninth Revision codes for OSA. Prevalence, prevalence odds ratio (POR), and confidence intervals (CIs) were calculated correcting for gender and age group. RESULTS: The prevalence rates of OSA were 0.8%, 2.8%, and 3.2% for men and 0.4%, 1.4%, and 1.8% for women aged 20 to 39 years, 40 to 59 years, and >or= 60 years, respectively. Compared to groups of corresponding age and gender who had not received prescriptions for either hypertension or depression, the highest PORs were found in patients receiving medications from both categories: 18.30 (95% CI, 10.69 to 25.66), 5.72 (95% CI, 4.10 to 6.70), and 4.47 (95% CI, 2.45 to 7.01) for men, and 17.43 (95% CI, 9.54 to 28.67), 7.29 (95% CI, 5.20 to 9.29), and 2.72 (95% CI, 1.48 to 4.73) for women. CONCLUSIONS: We found that the likelihood of having a diagnosis of OSA increases when either antihypertensive or antidepressant medications have been prescribed. The probability is highest in the young and middle-age groups receiving prescriptions for both medications. The possibility of OSA should be considered in any patient with hypertension and depression or unexplained fatigue who is receiving antihypertensive and antidepressant medications.

Left ventricular hypertrophy is a common echocardiographic abnormality in severe obstructive sleep apnea and reverses with nasal continuous positive airway pressure.

STUDY OBJECTIVES: To determine cardiac structural abnormalities by echocardiography in subjects with severe obstructive sleep apnea (OSA), and to determine the long-term effects of nasal continuous positive airway pressure (CPAP) on such abnormalities. DESIGN: Polysomnography was conducted on oximetry-screened patients who showed a desaturation index > 40/h and > or = 20% cumulative time spent below 90%. From these, 25 patients with severe OSA but without daytime hypoxemia underwent echocardiography prior to, then 1 month and 6 months following initiation of CPAP treatment. SETTING: Outpatient sleep disorders center. RESULTS: Of the 25 patients, 13 patients (52%) had hypertension by history or on physical examination. Baseline echocardiograms showed that severe OSA was associated with numerous cardiovascular abnormalities, including left ventricular hypertrophy (LVH) [88%], left atrial enlargement (LAE) [64%], right atrial enlargement (RAE) [48%], and right ventricular hypertrophy (16%). In all patients (intent to treat) as well as those patients compliant with CPAP therapy (84% > 3 h nightly), there was a significant reduction in LVH after 6 months of CPAP therapy as measured by interventricular septal distance (baseline diastolic mean, 13.0 mm; 6-month mean after CPAP, 12.3 mm; p < 0.02). RAE and LAE were unchanged after CPAP therapy. CONCLUSIONS: LVH was present in high frequency in subjects with severe OSA and regressed after 6 months of nasal CPAP therapy.

Sleep-disordered breathing associated with long-term opioid therapy.

Three patients are described who illustrate distinctive patterns of sleep-disordered breathing that we have observed in patients who are receiving long-term, sustained-release opioid medications. Polysomnography shows respiratory disturbances occur predominantly during non-rapid eye movement (NREM) sleep and are characterized by ataxic breathing, central apneas, sustained hypoxemia, and unusually prolonged obstructive "hypopneas" secondary to delayed arousal responses. In contrast to what is usually observed in subjects with obstructive sleep apnea (OSA), oxygen desaturation is more severe and respiratory disturbances are longer during NREM sleep compared to rapid eye movement sleep. Further studies are needed regarding the effects of opioids on respiration during sleep as well as the importance of interaction with other medications and associated risk factors for OSA.