Associations between early sleep-disordered breathing following moderate-to-severe traumatic brain injury and long-term chronic pain status: a Traumatic Brain Injury Model Systems study.

STUDY OBJECTIVES: To explore the relationship between polysomnography-derived respiratory indices and chronic pain status among individuals following traumatic brain injury (TBI). METHODS: Participants (n = 66) with moderate to severe TBI underwent polysomnography during inpatient acute rehabilitation and their chronic pain status was assessed at 1- to 2-year follow-up as part of the TBI Model Systems Pain Collaborative Study. Pairwise comparisons across pain cohorts (ie, chronic pain, no history of pain) were made to explore differences on polysomnography indices. RESULTS: Among our total sample, approximately three-quarters (74.2%) received sleep apnea diagnoses utilizing American Academy of Sleep Medicine criteria, with 61.9% of those endorsing a history of chronic pain. Of those endorsing chronic pain, the average pain score was 4.8 (standard deviation = 2.1), with a mean interference score of 5.3 (2.7). Pairwise comparisons revealed that those endorsing a chronic pain experience at follow-up experienced categorically worse indicators of sleep-related breathing disorders during acute rehabilitation relative to those who did not endorse chronic pain. Important differences were observed with elevations on central (chronic pain: 2.6; no pain: 0.8 per hour) and obstructive apnea (chronic pain: 15.7; no pain: 11.1 per hour) events, as well as oxygen desaturation indices (chronic pain: 19.6; no pain: 7.9 per hour). CONCLUSIONS: Sleep-disordered breathing appears worse among those who endorse chronic pain following moderate-to-severe TBI, but additional research is needed to understand its relation to postinjury pain. Prospective investigation is necessary to determine how clinical decisions (eg, opioid therapy) and intervention (eg, positive airway pressure) may mutually influence outcomes. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Comparison of Sleep Apnea Assessment Strategies to Maximize TBI Rehabilitation Participation and Outcome (C-SAS); URL: https://clinicaltrials.gov/ct2/show/NCT03033901; Identifier: NCT03033901. CITATION: Martin AM, Pinto SM, Tang X, et al. Associations between early sleep-disordered breathing following moderate-to-severe traumatic brain injury and long-term chronic pain status: a Traumatic Brain Injury Model Systems study. J Clin Sleep Med. 2023;19(1):135-143.

The Impact of Opioid Medications on Sleep Architecture and Nocturnal Respiration During Acute Recovery From Moderate to Severe Traumatic Brain Injury: A TBI Model Systems Study.

OBJECTIVES: To describe patient and clinical characteristics associated with receipt of opioid medications and identify differences in sleep quality, architecture, and sleep-related respiration between those receiving and not receiving opioid medications. SETTING: Acute inpatient rehabilitation care for moderate to severe traumatic brain injury (TBI). PARTICIPANTS: A total of 248 consecutive admissions for inpatient rehabilitation care following moderate to severe TBI (average age of 43.6 years), who underwent level 1 polysomnography (PSG) (average time since injury: 120 days) across 6 sites. DESIGN: Cross-sectional, secondary analyses. MAIN MEASURES: The PSG sleep parameters included total sleep time (TST), sleep efficiency (SE), wake after sleep onset, rapid eye movement (REM) latency, sleep staging, and arousal and awakening indices. Respiratory measures included oxygen saturation, central apnea events per hour, obstructive apnea and hypopnea events per hour, and total apnea-hypopnea index. RESULTS: After adjustment for number of prescribed medication classes, those receiving opioid medications on the day of PSG experienced increased TST relative to those not receiving opioid medications (estimated mean difference [EMD] = 31.58; 95% confidence interval [CI], 1.9-61.3). Other indices of sleep did not differ significantly between groups. Among respiratory measures those receiving opioids on the day of PSG experienced increased frequency of central sleep apnea events during total (EMD = 2.92; 95% CI, 0.8-5.0) and non-REM sleep (EMD = 3.37; 95% CI, 1.0-5.7) and higher frequency of obstructive sleep apnea events during REM sleep (EMD = 6.97; 95% CI, 0.1-13.8). Compared with those who did not, receiving opioids was associated with lower oxygen saturation nadir during total sleep (EMD = -3.03; 95% CI, -5.6 to -0.4) and a greater number of oxygen desaturations across REM (EMD = 8.15; 95% CI, 0.2-16.1), non-REM (EMD = 7.30; 95% CI, 0.3-14.4), and total sleep (EMD = 8.01; 95% CI, 0.8-15.2) Greater total apnea-hypopnea index was observed during REM (EMD = 8.13; 95% CI, 0.8-15.5) and total sleep (EMD = 7.26; 95% CI, 0.08-14.4) for those receiving opioids. CONCLUSION: Opioid use following moderate to severe TBI is associated with an increase in indicators of sleep-related breathing disorders, a modifiable condition that is prevalent following TBI. As sleep-wake disorders are associated with poorer rehabilitation outcomes and opioid medications may frequently be administered following traumatic injury, additional longitudinal investigations are warranted in determining whether a causal relation between opioids and sleep-disordered breathing in those following moderate to severe TBI exists. Given current study limitations, future studies can improve upon methodology through the inclusion of indication for and dosage of opioid medications in this population when examining these associations.

Comparison of Diagnostic Sleep Studies in Hospitalized Neurorehabilitation Patients With Moderate to Severe Traumatic Brain Injury.

BACKGROUND: OSA is prevalent during a time of critical neural repair after traumatic brain injury (TBI). The diagnostic utility of existing sleep studies is needed to inform clinical management during acute recovery from TBI. RESEARCH QUESTION: This study aimed to evaluate the non-inferiority and diagnostic accuracy of a portable level 3 sleep study relative to level 1 polysomnography in hospitalized neurorehabilitation patients with TBI. STUDY DESIGN AND METHODS: This is a prospective clinical trial conducted at six TBI Model System study sites between May 2017 and February 2019. Of 896 admissions, 449 were screened and eligible for the trial, with 345 consented. Additional screening left 263 eligible for and completing simultaneous administration of both level 1 and level 3 sleep studies, with final analyses completed on 214 (median age = 42 years; ED Glasgow Coma Scale = 6; time to polysomnography [PSG] = 52 days). RESULTS: Agreement was moderate to strong (weighted kappa = 0.78, 95% CI, 0.72-0.83) with the misclassification commonly occurring with mild sleep apnea due to underestimation of apnea hypopnea index (AHI). Most of those with moderate to severe sleep apnea were correctly classified (n = 54/72). Non-inferiority was not demonstrated: the minimum tolerable specificity of 0.5 was achieved across all AHI cutoff scores (lower confidence limits [LCL] range, 0.807-0.943), but the minimum tolerable sensitivity of 0.8 was not (LCL range, 0.665-0.764). INTERPRETATION: Although the non-inferiority of level 3 portable diagnostic testing relative to level 1 was not established, strong agreement was seen across sleep apnea indexes. Most of those with moderate to severe sleep apnea were correctly identified; however, there was risk of misclassification with level 3 sleep studies underestimating disease severity for those with moderate to severe AHI and disease presence for those with mild AHI during early TBI neurorehabilitation.

Cost-Benefit Analysis From the Payor's Perspective for Screening and Diagnosing Obstructive Sleep Apnea During Inpatient Rehabilitation for Moderate to Severe TBI.

OBJECTIVE: To describe the cost benefit of 4 different approaches to screening for sleep apnea in a cohort of participants with moderate to severe traumatic brain injury (TBI) receiving inpatient rehabilitation from the payor's perspective. DESIGN: A cost-benefit analysis of phased approaches to sleep apnea diagnosis. SETTING: Six TBI Model System Inpatient Rehabilitation Centers. PARTICIPANTS: Trial data from participants (N=214) were used in analyses (mean age 44±18y, 82% male, 75% white, with primarily motor vehicle-related injury [44%] and falls [33%] with a sample mean emergency department Glasgow Coma Scale of 8±5). INTERVENTION: Not applicable. MAIN OUTCOME: Cost benefit. RESULTS: At apnea-hypopnea index (AHI) ≥15 (34%), phased modeling approaches using screening measures (Snoring, Tired, Observed, Blood Pressure, Body Mass Index, Age, Neck Circumference, and Gender [STOPBANG] [-$5291], Multivariable Apnea Prediction Index MAPI [-$5262]) resulted in greater cost savings and benefit relative to the portable diagnostic approach (-$5210) and initial use of laboratory-quality polysomnography (-$5,011). Analyses at AHI≥5 (70%) revealed the initial use of portable testing (-$6323) relative to the screening models (MAPI [-$6250], STOPBANG [-$6237) and initial assessment with polysomnography (-$5977) resulted in greater savings and cost-effectiveness. CONCLUSIONS: The high rates of sleep apnea after TBI highlight the importance of accurate diagnosis and treatment of this comorbid disorder. However, financial and practical barriers exist to obtaining an earlier diagnosis during inpatient rehabilitation hospitalization. Diagnostic cost savings are demonstrated across all phased approaches and OSA severity levels with the most cost-beneficial approach varying by incidence of OSA.

Incidence and predictors of adherence to sleep apnea treatment in rehabilitation inpatients with acquired brain injury.

OBJECTIVE: The purpose of this study was to describe incidence and assess predictors of adherence to Positive Airway Pressure (PAP) therapy for Obstructive Sleep Apnea (OSA) in persons with acquired brain injury (ABI). METHODS: A 2012-2015 retrospective analysis of consecutive ABI patients admitted for neurorehabilitation, referred for polysomnography (PSG), and prescribed PAP for OSA. Univariable linear regressions were conducted to examine predictors of average hours of nightly PAP use. Univariable logistic regressions were conducted to examine predictors of PAP adherence using the conventional clinical definition of ≥4 h per night ≥70% of the time. Persons with traumatic etiology were separately analyzed. RESULTS: ABI etiology was 51% traumatic, 36% stroke, and 13% other nontraumatic causes. Nearly two-thirds were nonadherent to PAP. For the overall sample, higher average nightly PAP usage was significantly predicted by positive hypertension diagnosis (ß = 0.271, p = 0.019). Likewise, greater adherence based on the conventional cutoff was predicted by poorer motor functioning at hospital admission (OR = 0.98, p = 0.001) and lower oxygen saturation nadir (OR = 0.99, p = 0.003). For those with traumatic injuries, greater adherence was predicted by poorer functional status at hospital admission (OR = 0.98, p = 0.010) and positive hypertension diagnosis (OR = 0.16, p = 0.023). CONCLUSIONS: In this study of hospitalized neurorehabilitation patients with ABI and comorbid OSA, predictors of adherence included lower oxygen saturation, poorer functional status and hypertension diagnosis, perhaps signifying the role of greater severity of illness on treatment adherence. High rates of refusal and nonadherence to frontline PAP therapy for sleep apnea is a concern for persons in recovery form ABI who are at a time of critical neural repair.

Concordance between current American Academy of Sleep Medicine and Centers for Medicare and Medicare scoring criteria for obstructive sleep apnea in hospitalized persons with traumatic brain injury: a VA TBI Model System study.

STUDY OBJECTIVES: The objective of this study was to compare obstructive sleep apnea (OSA), demographic, and traumatic brain injury (TBI) characteristics across the American Academy of Sleep Medicine (AASM) and Centers for Medicare and Medicare (CMS) scoring rules in moderate to severe TBI undergoing inpatient neurorehabilitation. METHODS: This is a secondary analysis from a prospective clinical trial of sleep apnea at 6 TBI Model System study sites (n = 248). Scoring was completed by a centralized center using both the AASM and CMS criteria for OSA. Hospitalization and injury characteristics were abstracted from the medical record, and demographics were obtained by interview by trained research assistants using TBI Model System standard procedures. RESULTS: OSA was prevalent using the AASM (66%) and CMS (41.5%) criteria with moderate to strong agreement (weighted κ = 0.64; 95% confidence interval = 0.58-0.70). Significant differences were observed for participants meeting AASM and CMS criteria (concordant group) compared with those meeting criteria for AASM but not CMS (discordant group). At an apnea-hypopnea index ≥ 5 events/h, the discordant group (n = 61) had lower Emergency Department Glasgow Coma Scale Scores consistent with greater injury severity (median, 5 vs 13; P = .0050), younger age (median, 38 vs 58; P < .0001), and lower body mass index (median, 22.1 vs 24.8; P = .0007) compared with the concordant group (n = 103). At an apnea-hypopnea index ≥ 15 events/h, female sex but no other differences were noted, possibly because of the smaller sample size. CONCLUSIONS: The underestimation of sleep apnea using CMS criteria is consistent with prior literature; however, this is the first study to report the impact of the criteria in persons with moderate to severe TBI during a critical stage of neural recovery. Management of comorbidities in TBI has become an increasing focus for optimizing TBI outcomes. Given the chronic morbidity after moderate to severe TBI, the impact of CMS policy for OSA diagnosis for persons with chronic disability and young age are considerable. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Comparison of Sleep Apnea Assessment Strategies to Maximize TBI Rehabilitation Participation and Outcome; Identifier: NCT03033901.

Comparative Effectiveness of Sleep Apnea Screening Instruments During Inpatient Rehabilitation Following Moderate to Severe TBI.

OBJECTIVE: To determine the diagnostic sensitivity and specificity and comparative effectiveness of traditional sleep apnea screening tools in traumatic brain injury (TBI) neurorehabilitation admissions. DESIGN: Prospective diagnostic comparative effectiveness trial of sleep apnea screening tools relative to the criterion standard, attended level 1 polysomnography including encephalography. SETTING: Six TBI Model System Inpatient Rehabilitation Centers. PARTICIPANTS: Between May 2017 and February 2019, 449 of 896 screened were eligible for the trial with 345 consented (77% consented). Additional screening left 263 eligible for and completing polysomnography with final analyses completed on 248. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Area under the curve (AUC) of screening tools relative to total apnea hypopnea index≥15 (AHI, moderate to severe apnea) measured at a median of 47 days post-TBI (interquartile range, 29-47). RESULTS: The Berlin high-risk score (receiving operating curve [ROC] AUC=0.634) was inferior to the Multivariable Apnea Prediction Index (MAPI) (ROC AUC=0.780) (P=.0211; CI, 0.018-0.223) and Snoring, Tired, Observed, Blood Pressure, Body Mass Index, Age, Neck Circumference, and Gender (STOPBANG) score (ROC AUC=0.785) (P=.001; CI, 0.063-0.230), both of which had comparable AUC (P=.7245; CI, -0.047 to 0.068). Findings were similar for AHI≥30 (severe apnea); however, no differences across scales was observed at AHI≥5. The pattern was similar across TBI severity subgroups except for posttraumatic amnesia (PTA) status wherein the MAPI outperformed the Berlin. Youden's index to determine risk yielded lower sensitivities but higher specificities relative to non-TBI samples. CONCLUSION: This study is the first to provide clinicians with data to support a choice for which sleep apnea screening tools are more effective during inpatient rehabilitation for TBI (STOPBANG, MAPI vs Berlin) to help reduce comorbidity and possibly improve neurologic outcome.

Functional improvement after severe brain injury with disorder of consciousness paralleling treatment for comorbid obstructive sleep apnoea: a case report.

Survivors of brain injury who have disorders of consciousness often have chronic functional deficits and disability. Obstructive sleep apnoea, a sleep-related breathing disorder, is a medical comorbid condition common among persons with brain injury and is injurious to health. Research on obstructive sleep apnoea treatment among brain-injured patients-particularly persons with disorders of consciousness-is sparse. This case study describes a patient with severe brain injury admitted for neurorehabilitation in a minimally conscious state. Obstructive sleep apnoea was identified and treated. Treatment compliance was variable, and functional motor and cognitive improvement were observed during periods of better compliance. Study design does not permit casual attribution for functional improvement, but identification and treatment of obstructive sleep apnoea are suggested as a possible way to promote recovery after brain injury.

Implementation of Actigraphy in Acute Traumatic Brain Injury (TBI) Neurorehabilitation Admissions: A Veterans Administration TBI Model Systems Feasibility Study.

BACKGROUND: Sleep problems and disorders are prevalent in patients with traumatic brain injury (TBI) and are associated with negative outcomes. Incidence varies because of challenges including differences in assessment methods, particularly in the acute stages of recovery when patients are cognitively impaired and unable to complete traditional self-report methods. Actigraphy (ACG) recently has been validated in the acute TBI rehabilitation setting and may serve as a superior method of assessing sleep-wake patterns at this stage of recovery. Although a few studies with small sample sizes have described the use of ACG, none have described feasibility and implementation protocols. OBJECTIVE: To describe the feasibility and implementation protocol of ACG to evaluate sleep-wake patterns and white-light exposure data in patients with acute TBI during inpatient rehabilitation. Sleep-wake patterns and light exposure data are presented to characterize the sample using these methods to inform future research. DESIGN: Retrospective study. SETTING: Acute inpatient rehabilitation unit at a Veterans' Affairs Polytrauma Rehabilitation Center. PARTICIPANTS: Veterans (age ≥18 years) admitted to inpatient rehabilitation and enrolled in the Traumatic Brain Injury Model Systems study who were admitted and discharged in the calendar year 2013. METHODS: Veterans underwent actigraph watch placement as soon as possible after admission. Records from the calendar year 2013 were reviewed to determine the number of admissions that met study criteria and what percentage of those patients had 3 days of continuous ACG data collected. The barriers to successful watch placement in this population were reviewed. Average sleep, light, and wake data from available records were collected for the study sample. MAIN OUTCOME MEASUREMENTS: Percentage of patients who met study criteria and who had 72 hours of continuous ACG data collected. The barriers to successful watch placement in this population were reviewed. Average sleep, light, and wake data from available records were collected. RESULTS: Of 22 eligible Traumatic Brain Injury Model Systems admissions, 3 consecutive nights of ACG data were successfully obtained for 86% (n = 19) of the sample. Barriers to data collection included patient access due to abbreviated lengths of stay, staff availability for ACG placement, and data collection protocols to prevent loss of data in Veterans' Affairs computing systems. CONCLUSIONS: ACG is feasible for collecting data about sleep, wake, and light exposure in patients who are in acute TBI inpatient rehabilitation settings. LEVEL OF EVIDENCE: III.

Incidence, Characterization, and Predictors of Sleep Apnea in Consecutive Brain Injury Rehabilitation Admissions.

OBJECTIVE: To prospectively examine the incidence and risk factors for sleep apnea in consecutive brain injury rehabilitation admissions. SETTING: Inpatient neurorehabilitation hospital. PARTICIPANTS: Participants (n = 86) were consecutive neurorehabilitation admissions. DESIGN: Retrospective analysis of prospectively collected data. MAIN MEASURES: Polysomnography. RESULTS: Half (49%) of the sample was diagnosed with sleep apnea. For the full sample, univariate logistic regression revealed age (odds ratio: 1.08; 95% confidence interval: 1.04-1.11) and hypertension (odds ratio: 7.77; 95% confidence interval: 2.81-21.47) as significant predictors of sleep apnea diagnosis. Results of logistic regression conducted within the traumatic brain injury group revealed age (odds ratio: 1.07; 95% confidence interval: 1.02-1.13) as the only significant predictor of apnea diagnosis after adjustment for other variables. Hierarchical generalized linear regression models for the prediction of apnea severity (ie, apnea-hypopnea index found that Functional Independence Measure Cognition Score (P = .01) and age (P < .01) were significant predictors. Following adjustment for all other terms, only age (P < .01) remained significant. CONCLUSION: Sleep apnea is prevalent in acute neurorehabilitation admissions and traditional risk profiles for sleep apnea may not effectively screen for the disorder. Given the progressive nature of obstructive sleep apnea and morbidity associated with even mild obstructive sleep apnea, early identification and intervention may address comorbidities influencing acute and long-term outcome.

Concordance of Actigraphy With Polysomnography in Traumatic Brain Injury Neurorehabilitation Admissions.

OBJECTIVE: To examine concordance of accelerometer-based actigraphy (ACG) with polysomnography (PSG) in the determination of sleep states in inpatients with traumatic brain injury (TBI), and examine the impact of injury severity and comorbid conditions (spasticity, apnea) on concordance. PARTICIPANTS: This was a convenience sample of 50 participants with primarily severe TBI. DESIGN: This was a retrospective chart review of concurrent administration of PSG with ACG in nonconsecutive rehabilitation admissions with TBI. MAIN MEASURES: Total sleep time and sleep efficiency were measured by PSG and ACG. RESULTS: Moderate to strong correlations between ACG and PSG were observed for total sleep time (r = 0.78, P < .01) and sleep efficiency (r = 0.66, P < .01). PSG and ACG estimates of total sleep time (316 minutes vs 325 minutes, respectively) and sleep efficiency (78% vs 77%, respectively) were statistically indistinguishable. CONCLUSIONS: Actigraphy is a valid proxy for monitoring of sleep in this population across injury severity and common comorbidity groups. However, further research with larger sample sizes to examine concordance in patients with TBI with disorder of consciousness and spasticity is recommended.

Prospective evaluation of the nature, course, and impact of acute sleep abnormality after traumatic brain injury.

OBJECTIVE: To prospectively characterize the prevalence, course, and impact of acute sleep abnormality among traumatic brain injury (TBI) neurorehabilitation admissions. DESIGN: Prospective observational study. SETTING: Freestanding rehabilitation hospital. PARTICIPANTS: Primarily severe TBI (median emergency department Glasgow Coma Scale [GCS] score=7; N=205) patients who were mostly men (71%) and white (68%) were evaluated during acute neurorehabilitation. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Delirium Rating Scale-Revised-98 (DelRS-R98) was administered weekly throughout rehabilitation hospitalization. DelRS-R98 item 1 was used to classify severity of sleep-wake cycle disturbance (SWCD) as none, mild, moderate, or severe. SWCD ratings were analyzed both serially and at 1 month postinjury. RESULTS: For the entire sample, 66% (mild to severe) had SWCD at 1 month postinjury. The course of the SWCD using a subset (n=152) revealed that 84% had SWCD on rehabilitation admission, with 63% having moderate to severe ratings (median, 24d postinjury). By the third serial exam (median, 35d postinjury), 59% remained with SWCD, and 28% had moderate to severe ratings. Using general linear modeling and adjusting for age, emergency department GCS score, and days postinjury, presence of moderate to severe SWCD at 1 month postinjury made significant contributions in predicting duration of posttraumatic amnesia (P<.01) and rehabilitation hospital length of stay (P<.01). CONCLUSIONS: Results suggest that sleep abnormalities after TBI are prevalent and decrease over time. However, a high percent remained with SWCD throughout the course of rehabilitation intervention. Given the brevity of inpatient neurorehabilitation, future studies may explore targeting SWCD to improve early outcomes, such as cognitive functioning and economic impact, after TBI.

The effects of arterial blood pressure on rebleeding when BleedArrest, Celox and TraumaDex are used in a porcine model of lethal femoral injury.

Uncontrolled bleeding remains the leading cause of preventable death in trauma. Hemostatic agents are effective in hemorrhage control but often fail following high-volume crystalloid resuscitation. Aggressive fluid resuscitation increases the blood pressure which may dislodge the newly formed clot causing rebleeding. The purpose of this study was to determine the systolic blood pressure (SBP) and the mean arterial pressure (MAP) at which rebleeding occurs when a clot is formed by one of these hemostatic agents (BleedArrest, TraumaDex, or Celox) compared to a control group. This was a prospective, experimental study using male 5 Yorkshire swine per group (BleedArrest, TraumaDex, Celox, or control). The femoral artery and vein were transected to simulate a traumatic injury. Subjects were allowed to bleed for 60 seconds then one of the agents was poured into the wound. The control group underwent the same procedures but without the hemostatic agent. After 30 minutes, dressings were removed and the SBP was increased incrementally using intravenous phenylephrine until rebleeding occurred or until the arterial blood pressure reached 210 mm/Hg. The SBP and MAP were significantly higher in the BleedArrest, TraumaDex, and Celox groups compared to a control group (p < 0.05).

Evidence for early right ventricular and septal mechanical activation (interventricular dyssynchrony) in pulmonary hypertension.

This study sought to characterize mechanical activation in pulmonary arterial hypertension (PAH) using 2-dimensional echocardiography with tissue Doppler imaging. Whether pathologic alterations of the right ventricle in PAH affect interventricular dyssynchrony due to changes in mechanical activation of the septum and the right ventricle is unclear. We studied 20 patients with PAH (14 women, mean age 55 +/- 16 years) and 20 healthy controls (15 women, mean age 41 +/- 11 years) that underwent tissue Doppler imaging between July 2006 and May 2007. PAH was associated with accelerated right ventricular (RV) (p <0.0001) and septal (p = 0.022) activation times, but no differences were found in lateral wall activation times between groups (p = 0.35). Measures of ventricular dyssynchrony indicated that patients with PAH had significantly lower RV-lateral wall delays (patients 3.2 +/- 66.2 ms vs controls 56.7 +/- 52.0 ms, p = 0.007), reflecting a faster activation of the right ventricle relative to the lateral wall than controls. In conclusion, PAH is associated with interventricular dyssynchrony manifested by accelerated RV free wall and septal activation times. Whether such dyssynchrony should serve as a therapeutic target remains to be determined.

For individuals with obstructive sleep apnea, institution of CPAP therapy is associated with an amelioration of symptoms of depression which is sustained long term.

OBJECTIVE: To assess the sustainability of an improvement in symptoms of depression using CPAP therapy in patients with obstructive sleep apnea. PATIENTS/METHODS: Patients referred to our center for evaluation of obstructive sleep apnea who had a respiratory disturbance index (RDI) of > or =15 and who demonstrated a significant response to CPAP (50% or greater drop in RDI), were evaluated for symptoms of depression using the Beck Depression Inventory-Fast Screen for Medical Patients (BDI). These individuals were asked to complete the BDI assessment again after 4 to 6 weeks of treatment with CPAP (short-term follow-up), and then reassessed approximately one year later (long-term follow-up). RESULTS: In this group of patients, the institution of CPAP therapy resulted in a significant decrease in those symptoms of depression assessed by the BDI at both the short-term and long-term follow-up periods. CONCLUSIONS: For patients with OSA who continue CPAP therapy, we noted a statistically significant, sustained improvement in those symptoms of depression measured by the BDI.

On the potential clinical relevance of the length of arousals from sleep in patients with obstructive sleep apnea.

STUDY OBJECTIVES: To assess, in individuals referred for evaluation of obstructive sleep apnea, the potential clinical significance of brief versus longer arousals from sleep. METHODS: Full-night polysomnographic tracings from 100 patients referred for evaluation of obstructive sleep apnea were analyzed to delineate the duration of each arousal event. These data were then correlated to the patient's subjective perception of sleepiness as estimated by the Epworth Sleepiness Scale (ESS). RESULTS: A significant relationship (p < .0001, r(2) = .167) was noted between the frequency of the longer arousals (> 15 seconds) and the ESS. This relationship was significant, but distinctly weaker (p = .004, r(2) = .073), with the shorter arousals (3-15 seconds); moreover, the association with the brief arousals failed to remain significant (p = .678) after controlling for the effect of the longer arousals. CONCLUSIONS: Individuals with obstructive sleep apnea experience frequent respiratory event associated cortical arousals, many of which are greater than 15 seconds in duration. These longer arousals, which, in this study, constituted 18.4% of all arousals and accounted for 37.5% of the total arousal time, correlate more closely with the ESS than does the frequency or time attributable to the more numerous brief arousals. This suggests that these more-prolonged arousal events may have a greater impact on the restorative aspect of sleep, or on the perception thereof.

Symptoms of depression in individuals with obstructive sleep apnea may be amenable to treatment with continuous positive airway pressure.

OBJECTIVE: To assess the reversibility of symptoms of depression using continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA). PATIENTS/METHODS: Patients referred to our center for evaluation of OSA who had a respiratory disturbance index (RDI) > or = 15 and who demonstrated a significant response to CPAP (> or = 50% drop in RDI) were evaluated for the symptoms of depression using the Beck Depression Inventory (BDI), and then reassessed after 4 to 6 weeks of treatment with CPAP at home. RESULTS: In this group of patients, the institution of CPAP therapy resulted in a significant (p < 0.0001) decrease in those symptoms of depression as assessed by the BDI (BDI at baseline, 4.1 +/- 3.7; BDI after CPAP, 1.0 +/- 2.0). This change in BDI was noted both in those individuals who had received an antidepressant prescription prior to referral, and in those who had not. An analysis of variance failed to reveal any effect on these data related to gender or baseline RDI. CONCLUSIONS: Patients with OSA may present to their primary care physician with symptoms suggesting a diagnosis of depression. In some of these individuals, the symptoms of depression may be ameliorated with CPAP.

The pulse transit time arousal index in obstructive sleep apnea before and after CPAP.

BACKGROUND AND PURPOSE: Pulse transit time (PTT) is a non-invasive index which reflects changes in peripheral vascular resistance and intrathoracic pressure. PTT arousal index (PTT Ar/I) is defined as the frequency (number/hour) of a defined decrease in PTT which may serve as a marker for respiratory events, and associated arousals which occur in patients with obstructive sleep apnea (OSA). This study was designed to evaluate the PTT Ar/I before and after patients with OSA were treated with continuous positive airway pressure (CPAP). PATIENTS AND METHODS: Individuals referred for evaluation of possible OSA underwent split-night polysomnography (PSG). The findings from 144 consecutive patients with a respiratory disturbance index (RDI)>/=20, who demonstrated at least a 50% drop in RDI with CPAP, provide the basis for this analysis. The PTT Ar/I measured before and after CPAP were compared to other measures of severity for OSA, including RDI and arousal index. RESULTS: The PTT Ar/I correlates with the RDI (r=0.43, P

Depressive symptoms are independently predictive of carotid atherosclerosis.

The investigators tested whether depressive symptoms were predictive of carotid atherosclerosis, a marker of coronary atherosclerosis. Healthy participants (n = 219) underwent the baseline assessment of cardiovascular risk factors, including self-reported depressive symptoms, and were assessed for carotid plaque at 10-year follow-up. Adjusting for baseline cardiovascular risk factors, participants with elevated depression scores at baseline were >2 times as likely as those with no depressive symptoms to have carotid plaque.