Obstructive sleep apnea and chronic opioid use.

The use of opioids has been associated with development of sleep-disordered breathing, including central apneas, nocturnal oxygen desaturations, and abnormal breathing patterns. We describe sleep-disordered breathing and its subsequent treatment in a group of obstructive sleep apneic patients on chronic opioid therapy. Clinical evaluation followed by diagnostic overnight polysomnogram was performed in subjects on chronic opioid therapy who met the study criteria. All subjects had an initial CPAP titration followed by a repeat clinical evaluation. Subjects with an apnea-hypopnea index (AHI) ≥ 5 continued to report symptoms and had follow-up titration with bilevel positive therapy; then bilevel positive-pressure therapy with a back-up rate was then performed. Age-, sex-, and disease-severity-matched obstructive sleep apnea patients served as controls. Forty-four study participants, including a large group of women (50%), and 44 controls were enrolled in the study. Opioid subjects had AHI = 43.86 ± 1.19, with a central apnea index of 0.64 ± 1.36. Two abnormal breathing patterns were seen, including decreased inspiratory effort during an obstructive event and longer than expected pauses in breathing. Despite adequate titration with CPAP and bilevel positive-pressure therapy, nocturnal awakenings and central apnea awakenings persisted (AHI and central apnea indices of 13.81 ± 2.77 and 11.52 ± 2.12, respectively). Treatment with bilevel positive-pressure therapy with a back-up rate controlled the problem. Nonobese OSA patients with opioid intake have obstructive breathing with a different pattern. In this study, bilevel positive-pressure therapy with a back-up rate was the most effective treatment.

Arousal frequency is associated with increased fatigue in obstructive sleep apnea.

OBJECTIVE: Fatigue is an important and often underemphasized symptom in patients with obstructive sleep apnea (OSA). Sleep fragmentation, i.e., arousals and disruptions in sleep architecture, is common in patients with OSA and may potentially contribute to their fatigue. We hypothesized that arousal frequency and changes in sleep architecture contribute to the fatigue experienced by patients with OSA. DESIGN: Seventy-three patients with diagnosed but untreated OSA (AHI > or = 15) were enrolled in this study. A baseline polysomnogram was obtained, and fatigue was measured with the Multidimensional Fatigue Symptom Inventory-short form (MFSI-sf). We evaluated the association between fatigue and arousals and various polysomongraphic variables, including sleep stages and sleep efficiency. RESULTS: Significant correlations between MFSI-sf subscale scores and various arousal indices were noted. Emotional fatigue scores were associated with total arousal index (r = 0.416, p = .021), respiratory movement arousal index (r = 0.346, p = .025), and spontaneous movement arousal index (r = 0.378, p = .025). Physical fatigue scores were associated with total arousal index (r = 0.360, p = .033) and respiratory movement arousal index (r = 0.304, p = .040). Percent of stage 1 sleep and REM sleep were also associated with physical and emotional fatigue scores. Hierarchal linear regression analysis demonstrated that emotional fatigue scores were independently associated with spontaneous movement arousals after controlling for age, body mass index, depression, and sleep apnea severity. CONCLUSIONS: These findings suggest that arousals may contribute to the fatigue seen in patients with OSA.

The roles of TNF-alpha and the soluble TNF receptor I on sleep architecture in OSA.

OBJECTIVE: Patients with obstructive sleep apnea (OSA) have been described to have increased levels of inflammatory cytokines (particularly TNF-alpha) and have severely disturbed sleep architecture. Serum inflammatory markers, even in normal individuals, have been associated with abnormal sleep architecture. Not much is known about the role the TNF receptor plays in the inflammation of OSA nor if it is associated with changes in sleep architecture or arousals during the night. We hypothesized that the TNF receptor might play an important role in the inflammation as well as sleep architecture changes in patients with OSA. DESIGN: Thirty-six patients with diagnosed (AHI > 15) but untreated OSA were enrolled in this study. Baseline polysomnograms as well as TNF-alpha and soluble TNF receptor I (sTNF-RI) serum levels were obtained on all patients. We evaluated the association between serum levels of TNF-alpha and sTNF-RI with various polysomongraphic characteristics, including sleep stages and EEG arousals. RESULTS: sTNF-RI levels were significantly correlated with snore arousals (r value 0.449, p value 0.009), spontaneous movement arousals (r value 0.378, p value 0.025), and periodic limb movement arousals (r value 0.460, p value 0.008). No statistically significant correlations were observed with TNF-alpha to any polysomnographic variables. To control for statistical significance with multiple comparisons, a MANOVA was performed with TNF-alpha and sTNF-RI as dependent variables and sleep architecture measures and arousals as independent variables. The model for sTNF-RI was statistically significant (F value 2.604, p value 0.03), whereas the model for TNF-alpha was not, suggesting sleep quality significantly affects sTNF-RI. Hierarchal linear regression analysis demonstrated that sTNF-RI was independently associated with spontaneous movement arousal index scores after controlling for age, body mass index, and sleep apnea severity. CONCLUSIONS: These findings suggest that sTNF-RI is associated with arousals during sleep, but not with other measures in patients with OSA.

Sleep disruption in cystic fibrosis.

There has been a growing recognition that patients with cystic fibrosis have disrupted sleep. Current literature suggests that nocturnal episodes of hypoventilation with oxyhemoglobin desaturation are the predominant sleep disturbances with a limited understanding of other potential processes. This disturbed sleep can impose a significant burden on patients, particularly in the areas of daytime symptoms and quality of life. Some early evidence suggests that nocturnal supportive ventilation provides physiologic benefits as well as improvements in quality of life. Further objective studies are needed to identify other contributors to sleep fragmentation and to evaluate outcomes with nocturnal supportive ventilation.

Opioid medication and sleep-disordered breathing.

There has been a growing recognition of chronic pain that may be experienced by patients. There has been a movement toward treating these patients aggressively with pharmacologic and nonpharmacologic modalities. Opioids have been a significant component of the treatment of acute pain, with their increasing use in cases of chronic pain, albeit with some controversy. In addition to analgesia, opioids have many accompanying adverse effects, particularly with regard to stability of breathing during sleep. This article reviews the existing literature on the effects of opioids on sleep, particularly sleep-disordered breathing.