Perioperative complications in obstructive sleep apnea patients

BACKGROUND

Perioperative complications in obstructive sleep apnea (OSA) patients are described in a small series of case reports. No study to date systematically evaluates perioperative complications in a large number of OSA patients receiving surgeries other than those involving the pharynx.

METHODS

Names of the 860 OSA patients seen in a hospital-based sleep disorders center was cross-referenced with a list of the names of the 2,350 patients receiving surgeries in hospital during an 18 month period. In-patient and sleep center records of the 57 OSA patients receiving surgery were reviewed.

RESULTS

Nine perioperative complications occurred in eight of 48 OSA patients (17%) receiving general anesthesia. All of these complications were related to difficulties with airway management both pre- and postoperatively. Clinical characteristics including body mass index and Polysomnographie measurements of OSA severity did not prove to be useful predictors of perioperative complications.

CONCLUSIONS

The incidence of respiratory complications related to difficulties in airway management in OSA patients was higher than that reported in a recent study for all patients receiving general anesthesia (4%). The perioperative complications observed in these OSA patients are consistent with the underlying pathogenesis of OSA, pharyngeal obstruction. The absence of observed perioperative arrhythmias and myocardial ischemia is consistent with previous findings that sleep-related cardiac ischemia is uncommon in OSA patients. Our results suggest it is prudent to cautiously manage all OSA patients receiving surgeries involving general anesthesia.

Sleep architecture and its relationship to insomnia

The methods used to obtain and depict sleep data shape our understanding of sleep as a phenomenon. The standard criteria for describing sleep were developed in the late 1960s. These criteria, which were established on the basis of the polysomnographic equipment available at that time, called for the division of sleep into stages according to depth; the visual depiction of these stages led to the now widely accepted concept of "sleep architecture." Although the sleep architecture model remains useful, the technology that provided the model's framework for understanding sleep has been superseded by computer-assisted systems for recording and analyzing sleep that may allow us to acquire data on sleep that were unobtainable with older equipment. Future gathering and depiction of sleep data, regardless of the recording and assessment methods used, should minimize disruption of sleep during study, allow for computerized analysis of sleep parameters, and describe the data from the perspective of the effect that sleep and the problems surrounding it have on daytime functioning.

Comparative effects of nefazodone and fluoxetine on sleep in outpatients with major depressive disorder

BACKGROUND

Sleep disturbances are common in major depressive disorder. In previous open-label trials, nefazodone improved sleep continuity and increased rapid eye movement (REM) sleep, while not affecting stage 3/4 sleep or REM latency: in contrast, fluoxetine suppressed REM sleep. This study compared the objective and subjective effects of nefazodone and fluoxetine on sleep.

METHODS

This paper reports combined results of three identical, multisite, randomized, double-blind, 8-week, acute-phase trials comparing nefazodone (n = 64) with fluoxetine (n = 61) in outpatients with nonpsychotic major depressive disorder and insomnia. Sleep electroencephalographic (EEG) recordings were gathered at baseline and weeks 2, 4, and 8. Clinical ratings were obtained at weeks 1-4, 6, and 8.

RESULTS

Nefazodone and fluoxetine were equally effective in reducing depressive symptoms; however, nefazodone differentially and progressively increased (while fluoxetine reduced) sleep efficiency and reduced (while fluoxetine increased) the number of awakenings in a linear fashion over the 8-week trial. Fluoxetine, but not nefazodone, prolonged REM latency and suppressed REM sleep. Nefazodone significantly increased total REM sleep time. Clinical evaluations of sleep quality were significantly improved with nefazodone compared with fluoxetine.

CONCLUSIONS

Nefazodone and fluoxetine were equally effective antidepressants. Nefazodone was associated with normal objective, and clinician- and patient-rated assessments of sleep when compared with fluoxetine. These differential sleep EEG effects are consistent with the notion that nefazodone and fluoxetine may have somewhat different modes and spectra of action.

A normative study of the maintenance of wakefulness test (MWT)

The maintenance of wakefulness test (MWT) is a daytime polysomnographic procedure which quantifies wake tendency by measuring the ability to remain awake during soporific circumstances. We present normative data based on 64 healthy subjects (27 males and 37 females) who adhered to uniform MWT procedural conditions including polysomnographic montage, illuminance level, seating position, room temperature, meal timing, and subject instructions. When allowed a maximum trial duration of 40 min, subjects' mean sleep latency to the first epoch of sustained sleep was 35.2 +/- 7.9 min. The lower normal limit, defined as two standard deviations below the mean, was 19.4 min. Calculation of data on the basis of a maximum trial duration of 20 min and sleep latency to the first appearance of brief sleep (a microsleep episode or one epoch of any stage of sleep) yielded a mean sleep latency of 18.1 +/- 3.6 min and a lower normal limit of 10.9 min. Sleep latency scores were significantly higher than those previously reported in patients with disorders of excessive somnolence. Therefore, the MWT appears to be a useful procedure in differentiating groups with normal daytime wake tendency from those with impaired wake tendency and in identifying individuals with pathologic inability to remain awake under soporific circumstances.

HLA haplotypes, polysomnography, and pedigrees in a case series of patients with narcolepsy

An ongoing study of the genetics of narcolepsy ascertains families through a case series of narcoleptic probands using diagnostic criteria consisting of 1) clinical history of excessive somnolence, 2) a mean sleep latency on the multiple sleep latency test (MSLT) of less than 7.9 minutes, 3) the rapid eye movement (REM) sleep-related symptom of cataplexy, 4) nocturnal polysomnography ruling out sleep apnea syndrome, and 5) two or more transitions to REM sleep on the MSLT. All probands and first-degree relatives received clinical and laboratory evaluations as well as human leukocyte antigen (HLA) typing. Demographic characteristics of the 32 probands are as follows: 17 males and 15 females; mean age was 42.1 years (range 13-70 years). The polysomnographic data confirmed daytime sleepiness and increased tendency for REM sleep for the 32 probands. Nocturnal polysomnographic results are as follows: sleep latency, 3.2 minutes; total sleep time, 442 minutes. MSLT results are as follows: sleep latency, 3.1 minutes; REM latency, 6.9 minutes; number of REM periods, 3.2. HLA typing revealed the presence of the HLA haplotypes, DRB1*15 and DQB1*0602, in 21 narcoleptic probands, with two African-Americans having the DQB1*0602 but not the DRB1*15 allele. Among the 57 relatives of the 32 probands, 1/31 females and 7/26 males were found to be affected with narcolepsy (p < 0.02), which suggests a higher diagnostic rate in male relatives. The 21 probands who were positive for the DRB1*15 and DQB1*0602 haplotypes did not differ from the 10 probands who were negative for these alleles in terms of their nocturnal sleep parameters, MSLT findings, or clinical presentation. Three families with multiple individuals affected with narcolepsy are presented. Two families have more than one affected individual who does not have the high-risk HLA haplotype. In one of these families, the disease is segregating independently of any HLA haplotype. In the third family, there is cosegregation with HLA DRB1*15 and DQB1*0602. One family contains a pair of DNA-confirmed, monozygotic twins with narcolepsy who are discordant for cataplexy and have the HLA DR14(Dw9)/DQB1*0503 and DR4(Dw4)/DQB1*0302 haplotypes.

A comparison of nefazodone and fluoxetine on mood and on objective, subjective, and clinician-rated measures of sleep in depressed patients: a double-blind, 8-week clinical trial

BACKGROUND

Previous small trials have suggested that nefazodone does not suppress rapid-eye-movement (REM) sleep or increase REM latency in depressed patients, in contrast to fluoxetine. The effects of nefazodone and fluoxetine on sleep architecture and on clinician- and patient-rated sleep measures were directly compared in this 8-week, multicenter, double-blind, randomized, parallel-group study.

METHOD

Forty-four outpatients with moderate to severe, nonpsychotic major depressive disorder (DSM-III-R) and insomnia were randomly assigned to receive nefazodone (Days 1-7, 200 mg/day; Days 8-56, 400 mg/day) or fluoxetine (Days 1-56, 20 mg/day). Sleep measures were obtained at baseline, while patients were unmedicated, and at Weeks 2, 4, and 8 of treatment.

RESULTS

In 43 evaluable patients (23 nefazodone, 20 fluoxetine), nefazodone and fluoxetine demonstrated similar antidepressant efficacy. All significant values were p < .05. Fluoxetine significantly decreased sleep efficiency and REM sleep and increased number of awakenings, Stage 1 sleep, and REM latency compared with baseline. In contrast, nefazodone significantly decreased percentage of awake and movement time and did not alter sleep efficiency or number of awakenings, Stage 1 or REM sleep, or REM latency compared with baseline. Nefazodone was associated with significantly less change from baseline for sleep efficiency, number of awakenings, percentage of awake and movement time, percentage of REM and Stage 1 sleep, and REM latency compared with fluoxetine. Both fluoxetine- and nefazodone-treated patients also showed significant improvement in some clinician- and patient-rated sleep disturbance scores, but nefazodone-treated patients improved to a significantly greater extent than fluoxetine-treated patients in most measures.

CONCLUSION

While nefazodone and fluoxetine showed equivalent antidepressant efficacy, more objective, subjective, and clinician-rated measures of sleep disturbance were improved during treatment with nefazodone than with fluoxetine. These results suggest that antidepressant effects of medications can occur independently of drug-induced changes in objective, subjective, and clinician-rated measures of sleep. Further studies, including parallel placebo-controlled comparisons with nefazodone, are needed to further test this hypothesis.

The mandibular repositioning device: role in the treatment of obstructive sleep apnea

The role of oral appliances in the routine treatment of obstructive sleep apnea (OSA) is not well defined. This prospective study attempts to clarify the clinical role of a specific oral appliance, the mandibular repositioning device (MRD). This study evaluated the demographic, polysomnographic, and cephalometric radiographic findings predictive of treatment success or failure with the MRD. Twenty-nine patients were diagnosed with mild to severe OSA by nocturnal polysomnography. The majority of these patients were intolerant to nasal continuous positive airway pressure (CPAP) and all were fitted with a MRD. Twenty-three of these patients were compliant initially with MRD use and received post-treatment nocturnal polysomnogrpahy at a mean of 104 days after receiving the device. The respiratory disturbance index (RDI) decreased with MRD use (37 +/- 23 versus 18 +/- 20 events/hour, p < 0.001), and 16 of the 23 patients (69%) were considered responders (decrease in RDI > or = 50% and posttreatment RDI < or = 20). Measurements of subjective and objective daytime sleepiness, nocturnal oxygen desaturation, and snoring were all improved with MRD use. A pre-treatment RDI > 40 was present in four of the seven (67%) non-responders. Age, body mass index, and cephalometric radiographic measurements were not predictive of treatment outcome. Sixteen of 23 patients (70%) continue to use the MRD after 3.4 +/- 0.7 years. This study suggests that the MRD is useful in the long-term treatment of patients with OSA of mild to moderate severity.

Treatment of narcolepsy with methamphetamine

Eight pairs of subjects (each consisting of a narcoleptic and a control matched on the basis of age, sex, educational background and job) were evaluated under the following double-blind, randomized treatment conditions: baseline, placebo, low dose and high dose methamphetamine. Subjects were drug-free for 2 weeks prior to beginning the protocol. Methamphetamine was the only drug taken during the protocol and was given in a single morning dose of 0, 20 or 40-60 mg to narcoleptics and 0, 5 or 10 mg to controls. The protocol was 28 days long, with each of the four treatment conditions lasting 4 days followed by 3 days of washout. Nighttime polysomnography and daytime testing were done during the last 24 hours of each treatment condition. Daytime sleep tendency was assessed with the multiple sleep latency test (MSLT). Daytime performance was assessed with performance tests including a simple, computer-based driving task. Narcoleptics' mean MSLT sleep latency increased from 4.3 minutes on placebo to 9.3 minutes on high dose, compared with an increase from 10.4 to 17.1 minutes for controls. Narcoleptics' error rate on the driving task decreased from 2.53% on placebo to 0.33% on high dose, compared with a decrease from 0.22% to 0.16% for controls. The effects of methamphetamine on nocturnal sleep were generally dose-dependent and affected sleep continuity and rapid eye movement (REM) sleep. Elimination half life was estimated to be between 15.9 and 22.0 hours. Mild side effects emerged in a dose-dependent fashion and most often involved the central nervous system and gastrointestinal tract. We concluded that methamphetamine caused a dose-dependent decrease in daytime sleep tendency and improvement in performance in both narcoleptics and controls. Methamphetamine at doses of 40-60 mg allowed narcoleptics to function at levels comparable to those of unmedicated controls.

Maintenance of wakefulness test in obstructive sleep apnea syndrome

The usefulness of a 40-min per trial version of the maintenance of wakefulness test was assessed in 322 patients with obstructive sleep apnea. This test is a variant of the multiple sleep latency test in which patients are asked to remain awake in a quiet darkened room, and then monitored for electroencephalographic sleep onset. The four trials of the test are each stopped after 40 min. The mean sleep latency for all patients was 26.0 +/- 11.8 (SD) min. In a group of 24 patients who underwent treatment with nasal continuous positive airway pressure, the mean sleep latency increased from 18.0 +/- 12.3 to 31.9 +/- 10.4. The strongest nocturnal correlates of the MWT sleep latency were respiratory arousal index (r = -.35), mean oxygen saturation (r = .30), and weight/height ratio (r = -.25). These correlations were comparable to other studies using the MSLT. There were strong intercorrelations among the variables. In the more severe groups, measures of hypoxemia were more strongly correlated with MWT sleep latency. A two-factor analysis of variance using respiratory arousal index and several measures of oxyhemoglobin saturation indicated that both arousals from sleep and degree of hypoxemia contribute interactively to daytime dysfunction in patients with sleep apnea. The MWT appears useful in evaluating disability from daytime sleepiness.

Dream anxiety attacks (nightmares)

Nightmares--disturbances of dreaming sleep experienced at some point in time by most patients--are often seen in adults as a consequence of physical or emotional trauma. The presence of nightmares on a chronic basis in adult life may reflect specific personality characteristics and may define a population at risk for other psychiatric disturbances. Treatment, if indicated, may include psychotherapy and pharmacotherapy, with the regimen determined by the patient's specific history and symptoms.

Insomnia

Insomnia complaints are common in the general population and are seen with even greater frequency among psychiatric patients. In any patient, the development of insomnia complaints may reflect the combined influences of various psychological, psychophysiologic, pharmacologic, and other medical factors. The capacity to describe and define specific sleep disorders is an important component in the development of a workable plan for the treatment of these disturbances. Knowledge of specific behavioral and pharmacologic modalities is also necessary for the choice of safe and effective treatment approaches.

Polysomnographic findings in recently drug-free and clinically remitted depressed patients

Thirteen patients were examined by sleep polysomnograph (PSG) and the dexamethasone suppression test when clinically depressed and later when clinically remitted for six months and no longer receiving antidepressant medication for two to five weeks. None of the PSG variables (rapid eye movement [REM] latency, total sleep time, stage 1 through 4 times, REM time, and REM densities in periods 1 through 3) was significantly changed between symptomatic depression and symptom remission. While symptomatic, 11 of 13 patients exhibited a reduced REM latency (65 minutes or less). After clinical remission, eight of the 11 continued to exhibit reduced REM latencies, whereas the dexamethasone suppression test tended to show nonsuppression only during clinical depression. These data represent either longer-term (ie, slow to normalize) biologic consequences of a depressive episode or biologic antecedents of clinical depression that may herald a return of the depression in individuals vulnerable to recurrence. Whether PSG abnormalities identify clinically remitted patients who are prone to develop another depressive episode requires longitudinal follow-up studies.

Alprazolam vs amitriptyline in depressions with reduced REM latencies

This study was designed to compare the antidepressant effects of alprazolam, a triazolobenzodiazepine, with amitriptyline hydrochloride in a group of patients with nonpsychotic, major depressions diagnosed by Research Diagnostic Criteria. A mean rapid eye movement latency of less than 65 minutes was required to enter this study. Dexamethasone suppression tests were conducted before treatment. By strictly applied Research Diagnostic Criteria, 83.6% of the subjects were endogenous, and 34.7% were inpatients. A significantly greater percentage of alprazolam-treated patients responded within the first seven days of treatment. By the end of this six-week trial, alprazolam was associated with significant reductions in Hamilton, Beck, Covi, Raskin, and Carroll Rating scores (pretreatment to posttreatment). However, by the end of treatment the effects of amitriptyline exceeded those of alprazolam on both the Hamilton and Beck scales. These data indicate that alprazolam is not as effective as amitriptyline in major depressions with a shortened rapid eye movement latency.

A comparison of two unilateral ECT electrode placements: efficacy and electrical energy considerations

The authors compared the treatment outcomes and ECT energy requirements of 10 patients treated with the Muller unilateral placement method (secondary electrode in the frontal position) with those of 10 matched patients treated with the unilateral placement described by d'Elia (secondary electrode lateral to the vertex). Both groups showed a similar dramatic clinical improvement after ECT; however, the mean watt seconds required for the Muller method was nearly four times that for the d'Elia procedure. The treating physicians reported that the patients treated by the d'Elia method had fewer anterograde and retrograde memory disturbances and that they were alert and oriented sooner after ECT.