Society of Anesthesia and Sleep Medicine Position Paper on Patient Sleep During Hospitalization.

This article addresses the issue of patient sleep during hospitalization, which the Society of Anesthesia and Sleep Medicine believes merits wider consideration by health authorities than it has received to date. Adequate sleep is fundamental to health and well-being, and insufficiencies in its duration, quality, or timing have adverse effects that are acutely evident. These include cardiovascular dysfunction, impaired ventilatory function, cognitive impairment, increased pain perception, psychomotor disturbance (including increased fall risk), psychological disturbance (including anxiety and depression), metabolic dysfunction (including increased insulin resistance and catabolic propensity), and immune dysfunction and proinflammatory effects (increasing infection risk and pain generation). All these changes negatively impact health status and are counterproductive to recovery from illness and operation. Hospitalization challenges sleep in a variety of ways. These challenges include environmental factors such as noise, bright light, and overnight awakenings for observations, interventions, and transfers; physiological factors such as pain, dyspnea, bowel or urinary dysfunction, or discomfort from therapeutic devices; psychological factors such as stress and anxiety; care-related factors including medications or medication withdrawal; and preexisting sleep disorders that may not be recognized or adequately managed. Many of these challenges appear readily addressable. The key to doing so is to give sleep greater priority, with attention directed at ensuring that patients' sleep needs are recognized and met, both within the hospital and beyond. Requirements include staff education, creation of protocols to enhance the prospect of sleep needs being addressed, and improvement in hospital design to mitigate environmental disturbances. Hospitals and health care providers have a duty to provide, to the greatest extent possible, appropriate preconditions for healing. Accumulating evidence suggests that these preconditions include adequate patient sleep duration and quality. The Society of Anesthesia and Sleep Medicine calls for systematic changes in the approach of hospital leadership and staff to this issue. Measures required include incorporation of optimization of patient sleep into the objectives of perioperative and general patient care guidelines. These steps should be complemented by further research into the impact of hospitalization on sleep, the effects of poor sleep on health outcomes after hospitalization, and assessment of interventions to improve it.

Effects of positive airway pressure on patients with obstructive sleep apnea during acute ascent to altitude.

RATIONALE: In acute ascent to altitude, untreated obstructive sleep apnea (OSA) is often replaced with central sleep apnea (CSA). In patients with obstructive sleep apnea who travel to altitude, it is unknown whether their home positive airway pressure (PAP) settings are sufficient to treat their obstructive sleep apnea, or altitude-associated central sleep apnea. METHODS: Ten participants with positive airway pressure-treated obstructive sleep apnea, who reside at 1,320 m altitude, underwent polysomnography on their home positive airway pressure settings at 1,320 m and at a simulated altitude of 2,750 m in a hypobaric chamber. Six of the participants were subsequently studied without positive airway pressure at 2,750 m. MEASUREMENTS AND MAIN RESULTS: At 1,320 m, all participants' sleep apnea was controlled with positive airway pressure on home settings; at 2,750, no participants' sleep apnea was controlled. At higher altitude, the apnea-hypopnea index was higher (11 vs. 2 events/h; P < 0.01), mostly due to hypopneas (10.5 vs. 2 events/h; P < 0.01). Mean oxygen saturations were lower (88 vs. 93%; P < 0.01) and total sleep time was diminished (349 vs. 393 min; P = 0.03). Four of six participants without positive airway pressure at 2,750 m required supplemental oxygen to prevent sustained oxygen saturation (as determined by pulse oximetry) less than 80%. Positive airway pressure also was associated with reduced central sleep apnea (0 vs. 1; P = 0.03), improved sleep time (358 vs. 292 min; P = 0.06), and improved sleep efficiency (78 vs. 63%; P = 0.04). CONCLUSIONS: Acute altitude exposure in patients with obstructive sleep apnea treated with positive airway pressure is associated with hypoxemia, decreased sleep time, and increased frequency of hypopneas compared with baseline altitude. Application of positive airway pressure at altitude is associated with decreased central sleep apnea and increased sleep efficiency.

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.

Health benefits of gastric bypass surgery after 6 years.

CONTEXT: Extreme obesity is associated with health and cardiovascular disease risks. Although gastric bypass surgery induces rapid weight loss and ameliorates many of these risks in the short term, long-term outcomes are uncertain. OBJECTIVE: To examine the association of Roux-en-Y gastric bypass (RYGB) surgery with weight loss, diabetes mellitus, and other health risks 6 years after surgery. DESIGN, SETTING, AND PARTICIPANTS: A prospective Utah-based study conducted between July 2000 and June 2011 of 1156 severely obese (body mass index [BMI] ≥ 35) participants aged 18 to 72 years (82% women; mean BMI, 45.9; 95% CI, 31.2-60.6) who sought and received RYGB surgery (n = 418), sought but did not have surgery (n = 417; control group 1), or who were randomly selected from a population-based sample not seeking weight loss surgery (n = 321; control group 2). MAIN OUTCOME MEASURES: Weight loss, diabetes, hypertension, dyslipidemia, and health-related quality of life were compared between participants having RYGB surgery and control participants using propensity score adjustment. RESULTS: Six years after surgery, patients who received RYGB surgery (with 92.6% follow-up) lost 27.7% (95% CI, 26.6%-28.9%) of their initial body weight compared with 0.2% (95% CI, -1.1% to 1.4%) gain in control group 1 and 0% (95% CI, -1.2% to 1.2%) in control group 2. Weight loss maintenance was superior in patients who received RYGB surgery, with 94% (95% CI, 92%-96%) and 76% (95% CI, 72%-81%) of patients receiving RYGB surgery maintaining at least 20% weight loss 2 and 6 years after surgery, respectively. Diabetes remission rates 6 years after surgery were 62% (95% CI, 49%-75%) in the RYGB surgery group, 8% (95% CI, 0%-16%) in control group 1, and 6% (95% CI, 0%-13%) in control group 2, with remission odds ratios (ORs) of 16.5 (95% CI, 4.7-57.6; P < .001) vs control group 1 and 21.5 (95% CI, 5.4-85.6; P < .001) vs control group 2. The incidence of diabetes throughout the course of the study was reduced after RYGB surgery (2%; 95% CI, 0%-4%; vs 17%; 95% CI, 10%-24%; OR, 0.11; 95% CI, 0.04-0.34 compared with control group 1 and 15%; 95% CI, 9%-21%; OR, 0.21; 95% CI, 0.06-0.67 compared with control group 2; both P < .001). The numbers of participants with bariatric surgery-related hospitalizations were 33 (7.9%), 13 (3.9%), and 6 (2.0%) for the RYGB surgery group and 2 control groups, respectively. CONCLUSION: Among severely obese patients, compared with nonsurgical control patients, the use of RYGB surgery was associated with higher rates of diabetes remission and lower risk of cardiovascular and other health outcomes over 6 years.

Predicting sleep apnea in bariatric surgery patients.

BACKGROUND: Because of the high prevalence and potentially serious complications of obstructive sleep apnea (OSA) in obese individuals, several prediction models have been developed to detect moderate-to-severe OSA in patients undergoing bariatric surgery. Using commonly collected variables (body mass index [BMI], age, observed sleep apnea, hemoglobin A1c, fasting plasma insulin, gender, and neck circumference), Dixon et al. developed a model with a sensitivity of 89% and specificity of 81% for patients undergoing laparoscopic adjustable gastric band surgery suspected to have OSA. The present study evaluated the prediction model of Dixon et al. in 310 gastric bypass patients (mean BMI 46.8 kg/m(2), age 41.6 years, 84.5% women), with no preselection for OSA symptoms in a bariatric surgery partnership. METHODS: The patients underwent overnight limited polysomnography to determine the presence and severity of OSA as measured using the apnea-hypopnea index. RESULTS: Of the 310 patients, 44.2% had moderate-to-severe OSA (apnea-hypopnea index ≥ 15/h). Most variables in the Dixon model were associated with a greater prevalence of OSA. The sensitivity (75%) and specificity (57%) for the model-based classification of OSA were considerably lower in the present sample than originally reported. An alternate prediction model identified 10 unique predictors of OSA. The presence of ≥ 5 of these predictors modestly improved the sensitivity (77%) and greatly improved the specificity (77%) in predicting an apnea-hypopnea index of ≥ 15/h. When applied to the validation sample, the sensitivity (76%) and specificity (72%) were essentially the same. CONCLUSION: Although the Dixon model and our model included overlapping predictors (BMI, gender, age, neck circumference), when applied in our sample of gastric bypass patients, neither model achieved the sensitivity and specificity for predicting OSA previously reported by Dixon et al.

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.

Sleep apnea, reproductive hormones and quality of sexual life in severely obese men.

The effect of sleep apnea on the reproductive function of obese men is not entirely elucidated. The objective of this study was to define the effect of sleep apnea on the reproductive hormones and sexual function in obese men. This study included 89 severely obese men with BMI ≥35 kg/m2 considering gastric bypass surgery. Anthropometrics (weight, and BMI), reproductive hormones, and sleep studies were measured. The sexual quality of life was assessed using the Impact of Weight on Quality of Life-Lite questionnaire (IWQOL-Lite). The mean age of our patients was 46.9 ± 11.0 years, the mean BMI was 47.8 ± 8.7 kg/m2 and the mean weight was 337.7 ± 62.4 lb. After correction for age and BMI, means of free testosterone per severity group of sleep apnea were as follows: no or mild sleep apnea 74.4 ± 3.8 pg/ml, moderate sleep apnea 68.6 ± 4.2 pg/ml, and severe sleep apnea 60.2 ± 2.92 pg/ml, P = 0.014. All other parameters of sleep apnea including hypopnea index, percent time below a SpO2 of 90%, and percent time below a SpO2 of 80% were also negatively correlated with testosterone levels after correction for age and BMI. BMI and presence of coronary artery disease decreased the sexual quality of life. Sleep apnea was associated with reduced sexual quality of life. In summary, sleep apnea negatively affects testosterone levels independent of BMI. Severely obese men had decreased sexual quality of life.

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.

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.

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.