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Biomedical subjects

Ronald D Chervin

Publications and source records attributed to Ronald D Chervin.

At least 19 recordsLinked to original sources
PubMed2006

Correlates of daytime sleepiness in patients with asthma.

BACKGROUND AND PURPOSE: Patients with asthma often complain of daytime sleepiness, which is usually attributed to a direct effect of asthma on nocturnal sleep quality. We investigated this and other potential explanations for daytime sleepiness among asthmatics. PATIENTS AND METHODS: One hundred fifteen adult asthmatics were assessed for perceived daytime sleepiness (one question item), subjective sleepiness (Epworth Sleepiness Scale score, ESS), obstructive sleep apnea risk (Sleep Apnea scale score within Sleep Disorders Questionnaire, SA-SDQ), asthma severity step, relevant comorbid conditions, and current asthma medications. RESULTS: Among all subjects, 55% perceived excessive daytime sleepiness and 47% had ESS>10. Most subjects reported snoring (n=99, or 86%) and many snored habitually (n=44, 38%). The ESS correlated with SA-SDQ (P<0.0001), male gender (P=0.01), and asthma severity step (P=0.04). In a multiple regression model, the ESS was independently associated with SA-SDQ (P=0.0003) and male gender (P=0.02), but not with asthma severity step (P=0.51). There were no correlations between ESS and age, body mass index (BMI), forced expiratory volume in one second as percent of predicted value (FEV(1)%), comorbidities, or medication used to treat asthma. CONCLUSIONS: Sleepiness is common in asthmatics and may reflect occult obstructive sleep apnea more often than effects of asthma itself, other comorbid conditions, or asthma medications.

Adult↗
PubMed2006

Longitudinal assessment of noninvasive positive pressure ventilation adjustments in ALS patients.

The absence of data guiding optimal titration of noninvasive positive pressure ventilation (NIPPV) over time in ALS patients may contribute to the under-prescribing of NIPPV. We conducted a retrospective, single-center, chart review assessment of NIPPV pressure settings used for symptomatic treatment of ALS patients to determine NIPPV adjustments, and to compare survival between those who were tolerant and intolerant to NIPPV. All subjects were started on nocturnal NIPPV at 8 and 3 cm H2O inspiratory and expiratory pressure, respectively. Of the 18 tolerant subjects identified, 4 (22%) had no NIPPV pressure changes before death; 8 (44%), 1 change; 4 (22%), 2 changes; 1 (6%), 3 changes; and 1 (6%), 5 changes. Most pressure changes occurred during the first year of NIPPV initiation. The maximum pressure needed for comfort by any patient in this study was 19/5 cm H2O, while 4 (22%) found the original 8/3 cm H2O settings to be sufficient until death. Subjects in the tolerant group had better survival, when adjusting for age and site of symptom onset (bulbar versus limb), with a hazard ratio of 0.23 [95% confidence interval: 0.10, 0.54]. The current data suggest that ALS patients who are tolerant to NIPPV typically need at least one upward change in pressure settings. Tolerance to relatively low NIPPV inspiratory pressures is associated with improved survival.

Aged↗
PubMed2006

Evaluation of sham non-invasive ventilation for randomized, controlled trials in ALS.

Non-invasive positive pressure ventilation (NIV) treatment of advanced respiratory insufficiency prolongs survival in ALS. To investigate the critical question of whether earlier initiation of NIV might provide additional benefit, a randomized trial with an appropriate placebo is needed. This study evaluated sub-therapeutic (sham) continuous positive airway pressure as a potential placebo. In a single-blind design, 40 ALS patients with forced vital capacity>50% were randomized to receive 30 seconds (s) of either active NIV, with 8 cm H2O inspiratory and 4 cm H2O expiratory pressure, or sham NIV with<1 cm of H2O continuous positive airway pressure at the mask. A questionnaire was then used to assess whether subjects thought that they had received a "real" or "pretend" treatment trial. The subjects' median age was 60.5 years, and 38% were female. Twelve of 20 subjects (60%) who received active NIV and 7 (35%) of the 20 subjects who received sham thought that they had tried the active treatment (p = 0.11). Only 8 (20%) of all subjects were confident about their determination that they had received "real" or "pretend" NIV. Thus, sub-therapeutic (sham) continuous positive airway pressure is a promising placebo control for NIV trials in ALS.

Aged↗
PubMed2006

Sleep-disordered breathing, behavior, and cognition in children before and after adenotonsillectomy.

OBJECTIVES: Most children with sleep-disordered breathing (SDB) have mild-to-moderate forms, for which neurobehavioral complications are believed to be the most important adverse outcomes. To improve understanding of this morbidity, its long-term response to adenotonsillectomy, and its relationship to polysomnographic measures, we studied a series of children before and after clinically indicated adenotonsillectomy or unrelated surgical care. METHODS: We recorded sleep and assessed behavioral, cognitive, and psychiatric morbidity in 105 children 5.0 to 12.9 years old: 78 were scheduled for clinically indicated adenotonsillectomy, usually for suspected SDB, and 27 for unrelated surgical care. One year later, we repeated all assessments in 100 of these children. RESULTS: Subjects who had an adenotonsillectomy, in comparison to controls, were more hyperactive on well-validated parent rating scales, inattentive on cognitive testing, sleepy on the Multiple Sleep Latency Test, and likely to have attention-deficit/hyperactivity disorder (as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) as judged by a child psychiatrist. In contrast, 1 year later, the 2 groups showed no significant differences in the same measures. Subjects who had an adenotonsillectomy had improved substantially in all measures, and control subjects improved in none. However, polysomnographic assessment of baseline SDB and its subsequent amelioration did not clearly predict either baseline neurobehavioral morbidity or improvement in any area other than sleepiness. CONCLUSIONS: Children scheduled for adenotonsillectomy often have mild-to-moderate SDB and significant neurobehavioral morbidity, including hyperactivity, inattention, attention-deficit/hyperactivity disorder, and excessive daytime sleepiness, all of which tend to improve by 1 year after surgery. However, the lack of better correspondence between SDB measures and neurobehavioral outcomes suggests the need for better measures or improved understanding of underlying causal mechanisms.

Adenoidectomy↗
PubMed2006

Subjective sleepiness and polysomnographic correlates in children scheduled for adenotonsillectomy vs other surgical care.

STUDY OBJECTIVE: To compare a validated subjective measure of childhood sleepiness to an objective determination, assess the frequency of problematic sleepiness among children with suspected sleep-disordered breathing (SDB), and examine what standard or investigational polysomnographic measures of SDB predict subjective sleepiness. DESIGN: Prospective, cross-sectional. SETTING: University-based sleep disorders laboratory. PARTICIPANTS: Washtenaw County Adenotonsillectomy Cohort. INTERVENTION: Polysomnography followed by Multiple Sleep Latency Tests (MSLTs) in 103 children aged 5 to 12 years old: 77 were scheduled for clinically indicated adenotonsillectomy, usually for suspected SDB, and 26 for unrelated surgical care. Parents completed the previously validated, 4-item Pediatric Sleep Questionnaire-Sleepiness Subscale (PSQ-SS). RESULTS: Thirty-three (43%) of the children scheduled for adenotonsillectomy had high PSQ-SS scores, in comparison with only 3 (12%) of the controls (p = .004). The PSQ-SS scores correlated inversely with mean sleep latencies on the MSLTs (rho = -0.23, p = .006). The obstructive apnea index, apnea-hypopnea index, and respiratory disturbance index (which included respiratory event-related arousals identified by esophageal pressure monitoring) each correlated similarly with PSQ-SS scores, as did investigational quantification of esophageal pressures and respiratory cycle-related electroencephalographic changes (each rho approximately 0.30, p < .02). A stepwise regression identified sigma-frequency respiratory cycle-related electroencephalographic changes as the strongest independent predictor of subjective sleepiness among all subjects and particularly among those without obstructive sleep apnea. CONCLUSIONS: Sleepiness is a frequent problem among children with suspected SDB. Subjective sleepiness (PSQ-SS) reflects MSLT results to a limited extent, as in adults. Standard polysomnographic measures of SDB predict subjective sleepiness, but respiratory cycle-related electroencephalographic changes may offer additional clinical utility.

Adenoidectomy↗
PubMed2005

Validation of a polysomnographic score for REM sleep behavior disorder.

STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) was described more than 2 decades ago, but only 1 report on 5 patients and 5 normal subjects has tested the effectiveness of a method by which relevant polysomnographic findings can be quantified. We sought to validate this method in a larger sample of patients and control subjects. DESIGN: Cross-sectional. SETTING: Academic hospital. INTERVENTIONS: A clinician interviewed 17 patients at risk for RBD secondary to neurodegenerative disorders and 6 controls to assess whether RBD was present by history. Bed partners completed a questionnaire that quantified RBD symptom severity. From 2 consecutive nocturnal studies in each patient, 2 different polysomnographic RBD scores were generated: the percentage of 30-second REM epochs with at least 15 seconds of tonically maintained electromyographic activity, and the percentage of 3-second REM mini-epochs that contained phasic electromyographic bursts. MEASUREMENTS AND RESULTS: The tonic and phasic measures, combined together, were higher in patients with clinical determinations of probable or possible RBD (n=9) than in patients judged unlikely to have RBD (n=4, P = .023). The overall polysomnographic measure correlated with the symptom scores (rho = 0.42, P = .048). Specific polysomnographic RBD measures on night 1 correlated highly with those on night 2 (rho > 0.70, P < .0001). CONCLUSIONS: This quantitative method to assess the severity of RBD polysomnographic features appears to be both valid and reliable in patients at risk for RBD because of neurodegenerative disorders.

Aged↗
PubMed2005

Screening for obstructive sleep apnea in stroke patients: a cost-effectiveness analysis.

BACKGROUND AND PURPOSE: Obstructive sleep apnea (OSA) is common after acute ischemic stroke and predicts poor stroke recovery, but whether screening for OSA and treatment by continuous positive airway pressure (CPAP) improves neurological outcome is unknown. We used a cost-effectiveness model to estimate the magnitude of benefit that would be necessary to make polysomnography (PSG) and OSA treatment cost-effective in stroke patients. METHODS: A decision tree modeled 2 alternative strategies: PSG followed by 3 months of CPAP for those found to have OSA versus no screening. The primary outcome was the utility gained through OSA screening and treatment in relation to 2 common willingness-to-pay thresholds of $50,000 and $100,000 per quality-adjusted life year (QALY). RESULTS: Screening resulted in an incremental cost-effectiveness ratio of $49,421 per QALY. Screening is cost-effective as long as the treatment of stroke patients with OSA by CPAP improves patient utilities by >0.2 for a willingness-to-pay of $50,000 per QALY and 0.1 for a willingness-to-pay of $100,000 per QALY. CONCLUSIONS: A clinical trial assessing the effectiveness of CPAP in improving stroke outcome is warranted from a cost-effectiveness standpoint.

Cost-Benefit Analysis↗
PubMed2005

Snoring predicts hyperactivity four years later.

STUDY OBJECTIVES: Cross-sectional studies implicate snoring and sleep-disordered breathing as potential contributors to hyperactive behavior in some children. However, no prospective cohort study has demonstrated that symptoms of sleep-disordered breathing precede development of hyperactivity. PARTICIPANTS: Parents of 229 children aged 2 to 13 years, recruited at 2 general pediatrics clinics, completed initial and 4-year follow-up surveys. MEASUREMENTS: Surveys included a validated Pediatric Sleep Questionnaire about snoring, sleepiness, and overall risk of sleep-disordered breathing, and the hyperactivity index (expressed as a T-score) within the Conners' Parent Rating Scale. RESULTS: Thirty children (13%) were rated as hyperactive (hyperactivity index > 60) at follow-up. After adjustment for hyperactivity at baseline and stimulant use at follow-up, hyperactivity at follow-up was predicted by baseline habitual snoring (odds ratio = 4.4, 95% confidence interval [1.3, 14.7]) or loud snoring (4.5, [1.2, 17.5]) and by top-quartile composite scores for snoring (5.3, [1.7, 16.8]), sleepiness (3.0, [1.0, 9.4]), or sleep-disordered breathing (4.0, [1.4, 11.6]). CONCLUSIONS: This 4-year prospective cohort study shows that snoring and other symptoms of sleep-disordered breathing are strong risk factors for future emergence or exacerbation of hyperactive behavior. These findings support the hypothesis that untreated childhood sleep-disordered breathing contributes to development of hyperactivity.

Age of Onset↗
PubMed2005

Pediatric sleep-related breathing disorders and restless legs syndrome: how children are different.

Sleep-related breathing disorders and restless legs syndrome have traditionally been felt to affect primarily adults. Recent research suggests that these conditions are surprisingly common in children as well, and that clinical manifestations may differ considerably from those seen in adults. This review summarizes the clinical characteristics, epidemiology, pathophysiology, and treatment of sleep-related breathing disorders and restless legs syndrome in children. Particular emphasis is placed on recent research and on how the presentation and treatment of these conditions are different in children compared with adults.

Adolescent↗
PubMed2005

Insomnia and hypnotic use, recorded in the minimum data set, as predictors of falls and hip fractures in Michigan nursing homes.

OBJECTIVES: To examine the relationship between insomnia, hypnotic use, falls, and hip fractures in older people. DESIGN: Secondary analysis of a large, longitudinal, assessment database. SETTING: Four hundred thirty-seven nursing homes in Michigan. PARTICIPANTS: Residents aged 65 and older in 2001 with a baseline Minimum Data Set assessment and a follow-up 150 to 210 days later. MEASUREMENTS: Logistic regression modeled any follow-up report of fall or hip fracture. Predictors were baseline reports of insomnia (previous month) and use of hypnotics (previous week). Potential confounds taken into account included standard measures of functional status, cognitive status, intensity of resource utilization, proximity to death, illness burden, number of medications, emergency room visits, nursing home new admission, age, and sex. RESULTS: In 34,163 nursing home residents (76% women, mean age+/-standard deviation 84+/-8), hypnotic use did not predict falls (adjusted odds ratio (AOR)=1.13, 95% confidence interval (CI)=0.98, 1.30). In contrast, insomnia did predict future falls (AOR=1.52, 95% CI=1.38, 1.66). Untreated insomnia (AOR=1.55, 95% CI=1.41, 1.71) and hypnotic-treated (unresponsive) insomnia (AOR=1.32, 95% CI=1.02, 1.70) predicted more falls than did the absence of insomnia. After adjustment for confounding variables, insomnia and hypnotic use were not associated with subsequent hip fracture. CONCLUSION: In elderly nursing home residents, insomnia, but not hypnotic use, is associated with a greater risk of subsequent falls. Future studies will need to confirm these findings and determine whether appropriate hypnotic use can protect against future falls.

Accidental Falls↗
PubMed2004

Electroencephalographic changes during respiratory cycles predict sleepiness in sleep apnea.

Common polysomnographic measures of sleep-disordered breathing have shown a disappointing ability to predict important consequences such as excessive daytime sleepiness. Using novel analytic techniques, this study tested the hypothesis that numerous, brief disruptions in cortical activity could occur on a breath-to-breath basis during nonapneic sleep. Spectral analysis proved the existence of respiratory cycle-related electroencephalographic changes in each of 38 adult patients evaluated by polysomnography for sleep-disordered breathing. Furthermore, the tendency for sigma (13-15 Hz) electroencephalographic power to vary with the respiratory cycle predicted next-day sleepiness as measured by the multiple sleep latency test. The predictive value was enhanced when the analysis was limited to those 27 patients who had sleep-disordered breathing (more than 5 apneas or hypopneas per hour of sleep). In contrast, nocturnal rates of apneas and hypopneas, as well as minimal oxygen saturation, did not predict sleepiness as well. On average, sigma power increased notably during inspiration, whereas delta (1-4 Hz) power showed a simultaneous decrease. We conclude that electroencephalographic activity shows detectable changes during nonapneic respiratory cycles in adults evaluated for sleep-disordered breathing. Quantification of these changes, which may reflect numerous inspiratory microarousals, could prove useful in prediction of excessive daytime sleepiness.

Adult↗
PubMed2004

Method for detection of respiratory cycle-related EEG changes in sleep-disordered breathing.

STUDY OBJECTIVES: In sleep-disordered breathing (SDB), visual or computerized analysis of electroencephalogram (EEG) signals shows that disruption of sleep architecture occurs in association with apneas and hypopneas. We developed a new signal analysis algorithm to investigate whether brief changes in cortical activity can also occur with individual respiratory cycles. DESIGN: Retrospective. SETTING: University sleep laboratory. PARTICIPANTS: A 6 year-old boy with SDB. INTERVENTION: Polysomnography before and after clinically indicated adenotonsillectomy. MEASUREMENTS: For the first 3 hours of nocturnal sleep, a computer algorithm divided nonapneic respiratory cycles into 4 segments and, for each, computed mean EEG powers within delta, theta, alpha, sigma, and beta frequency ranges. Differences between segment-specific EEG powers were tested by analysis of variance. Respiratory cycle-related EEG changes (RCREC) were quantified. RESULTS: Preoperative RCREC were statistically significant in delta (P < .0001), theta (P < .001), and sigma (P < .0001) but not alpha or beta (P > .01) ranges. One year after the operation, RCREC in all ranges showed statistical significance (P < .01), but delta, theta, and sigma RCREC had decreased, whereas alpha and beta RCREC had increased. Preoperative RCREC also were demonstrated in a sequence of 101 breaths that contained no apneas or hypopneas (P < .0001). Several tested variations in the signal-analysis approach, including analysis of the entire nocturnal polysomnogram, did not meaningfully improve the significance of RCREC. CONCLUSIONS: In this child with SDB, the EEG varied with respiratory cycles to a quantifiable extent that changed after adenotonsillectomy. We speculate that RCREC may reflect brief but extremely numerous microarousals.

Adenoidectomy↗
PubMed2004

Correlates of respiratory cycle-related EEG changes in children with sleep-disordered breathing.

STUDY OBJECTIVES: To explore newly-identified respiratory cycle-related electroencephalographic changes (RCREC), which may represent microarousals, as correlates of neurobehavioral outcomes in children with sleep-disordered breathing (SDB). DESIGN: Retrospective. SETTING: University sleep laboratory. PARTICIPANTS: Ten research subjects, aged 6 to 10 years, with and without SDB. INTERVENTION: Polysomnography, Multiple Sleep Latency Tests, and tests of auditory attention before and after clinically-indicated tonsillectomy (n = 9) or hernia repair (n = 1, control). MEASUREMENTS: For the first 3 hours of nocturnal sleep, a computer algorithm quantified the degree to which delta, theta, and alpha electroencephalographic power varied within non-apneic respiratory cycles. Correlations between the RCREC and standard objective measures of SDB, sleepiness, and attention were explored. RESULTS: Five children had SDB (> 1 obstructive apnea per hour of sleep). Preoperative delta, theta, or alpha RCREC were statistically significant (P < .01) in all subjects except 1 without SDB and the 1 control. Theta RCREC correlated with rates of apneas and hypopneas (P = .01) and decreased after the apnea was treated. Postoperative changes in delta and theta RCREC predicted changes in Multiple Sleep Latency Test scores (rho = -0.84, P = .002; rho = -0.64, P = .05), whereas changes in rates of apneas and hypopneas did not (rho = -0.24, P = .50). Postoperative changes in attention tended to correlate with changes in delta RCREC (rho = -0.54, P = .11) more strongly than with changes in rates of apneic events (rho = -0.07, P = .84). CONCLUSIONS: The RCREC may reflect brief but numerous microarousals that could help to explain neurobehavioral consequences of SDB.

Algorithms↗
PubMed2004

Polysomnography in children scheduled for adenotonsillectomy.

OBJECTIVE: Several studies suggest that a reliable diagnosis of childhood sleep-disordered breathing (SDB) requires polysomnography (PSG). We compared clinical and PSG-based diagnoses in children scheduled for adenotonsillectomy (AT). Parent responses on a validated Pediatric Sleep Questionnaire were used to determine which symptoms could help identify children with clinical diagnoses of SDB but normal PSG. STUDY DESIGN AND SETTING: Thirty-four children aged 5.0 to 12.9 years and scheduled for AT to treat clinically diagnosed sleep-disordered breathing underwent laboratory-based PSG. Results were scored by 3 different criteria: 1) >1 obstructive apnea (2 breaths or longer) per hour of sleep; 2) >5 apneas or hypopneas per hour of sleep; or 3) >1 apnea, hypopnea, or respiratory event-related arousal per hour of sleep. RESULTS: Depending on the criterion used, the PSG documented SDB from a minimum of 18/34 subjects (53%, for criterion I) to as many as 30/34 subjects (88%, for criterion III). Among symptoms studied, absence of daytime mouth breathing and habitual snoring were most helpful in identification of children who had no evidence of SDB on PSG, by criterion I (Chi-square, P < 0.05). The absence of other common symptoms, such as "loud snoring" or "trouble breathing" at night, were not helpful. CONCLUSION: Children with clinical diagnoses of SDB may not consistently meet PSG criteria for this disorder. Questions about daytime mouth breathing and habitual snoring might help clinicians recognize children who would not have SDB on objective testing. SIGNIFICANCE: Clinical identification of SDB confirmable on PSG could be improved. However, available outcome data do not yet clarify whether clinical or PSG criteria best identify children likely to suffer morbidity from SDB. EBM RATING: C.

Adenoidectomy↗
PubMed2004

Toward cost-effectiveness analysis in the diagnosis and treatment of insomnia.

Insomnia is believed to have high prevalence, cost, and impact. However, comprehensive cost-effectiveness analyses (CEAs) of different diagnostic and treatment strategies have not been performed. Part of the reason is that limited data are available on prevalence, costs, and outcomes, each of which is key elements of any CEA. The authors conducted a MEDLINE search to review available literature. Epidemiological surveys have yielded variable results, depending on operational definitions and populations studied. Cost estimates have varied widely depending on whether indirect costs are included and which costs are considered. Impact on health-related quality of life appears to be substantial, but effects on utility scores-necessary to compare cost-effectiveness of insomnia management to that of other health care interventions-have not been reported. Furthermore, much of the data on health-related quality of life is cross-sectional, and cannot be used to test whether the identified associations are causal. The authors conclude that effective insomnia management holds promise as a cost-effective health care intervention. However, the CEA models that eventually may support this hypothesis will require accurate measures of direct and indirect costs, health state utility in treated and untreated insomnia, and prevalence data based on widely-accepted case definitions.

Cost-Benefit Analysis↗
PubMed2004

Cognitive executive dysfunction in children with mild sleep-disordered breathing.

In children, moderate or severe sleep-disordered breathing (SDB) may impair cognitive executive functions (EFs), including working memory, attention, and mental flexibility. The main objective of this study was to assess EFs in children with mild levels of SDB. Subjects for this descriptive study were 12 children (5 girls, 7 boys) aged 8.0 to 11.9 years (M = 9.0 +/- 0.85) participating in an ongoing study of the effects of adenotonsillectomy on behavior. Each subject had a nocturnal polysomnogram (PSG) and a multiple sleep latency test (MSLT). Mild SDB was considered present if the child's apnea/hypopnea index (AHI) was > or = 1 and < 10. Between MSLT nap attempts, each child completed standardized tests of EFs. The sample showed significant impairment of sustained attention and vigilance on a computerized continuous performance test. Children with low mental flexibility scores on the Children's Category Test (CCT) spent more time in stage 1 sleep (12.2% v. 9.5%, P = 0.028 on PSG) and showed a marginally higher arousal index (9.7 v. 6.5, P = 0.06 on PSG) than children with average or above-average CCT scores. AHI accounted for a significant proportion of the variance in CCT scores when 1 outlier was removed (N = 11, Rsq = 0.67, P = 0.002). Mild levels of SDB and associated sleep architecture disruptions may be associated with impairment of EFs in children.

Analysis of Variance↗