Faculty Bibliography

OBJECTIVES: The authors examined magnitude/variability of residual sleep disordered breathing (SDB) at pressures around the therapeutic continuous positive airway pressure (CPAP), and described a multinight approach to CPAP titration/retitration consisting of recording airflow and summarizing SDB over multiple nights at multiple pressures and choosing an optimal pressure from these summarized data. DESIGN: Prospective, single-center nonblinded study. PATIENTS: Ten female/18 male patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) (respiratory disturbance index [RDI] 67/h), 17 newly-initiated, 11 chronic CPAP users. INTERVENTIONS: A custom CPAP device (Fisher & Paykel Healthcare) recording airflow and pre-programmed to vary CPAP between 2-3 cm H2O below and 1-2 cm H2O above prescription pressure as determined by a full laboratory titration. RESULTS: Airflow and pressure continuously recorded for multiple nights (15.9 +/- 5.1 nights) at four to seven different pressures in each patient. SDB events manually scored from the airflow as apnea (airflow reduction > 90%), hypopnea (airflow reduction > 30% lasting 10 to 120 sec with inspira-tory flow limitation [IFL]) and runs of sustained IFL > 2 min identified. RDI = (apnea + hypopnea)/total sleep time calculated for each night and an obstruction index, including sustained IFL, also was calculated. PressureMultinight was obtained for each patient from multiple nights of data using two mathematical techniques. Night-to-night variability of SDB indices was low in some patients and significant in others. PressureMultinight could be determined in 17 of 28 patients and was similar to the in-laboratory pressure. CONCLUSIONS: This study showed that recording multiple nights of CPAP airflow in the home and analyzing these data for residual SDB provided useful information, including the possibility of determining a therapeutic prescription for fixed CPAP in most patients and identification of others with significant physiologic variability of SDB. CITATION: Callahan CY; Norman RG; Taxin Z; Mooney AM; Rapoport DM; Ayappa I. Multinight recording and analysis of continuous positive airway pressure airflow in the home for titration and management of sleep disordered breathing. SLEEP 2013;36(4):535-545.

BACKGROUND: Patients with obstructive sleep apnea/hypopnea syndrome (OSAHS), even those generally compliant with CPAP therapy, often intermittently discontinue CPAP. STUDY OBJECTIVE: Examine the impact of CPAP withdrawal on sleep, sleep disordered breathing (SDB), and daytime function in subjects with varying severity of OSAHS. PATIENTS AND INTERVENTIONS: Forty-two subjects (26M/16 F) with OSAHS (AHI4% = 45.2 +/- 35.5/h pretreatment) on CPAP for 4 months were evaluated on the second night of CPAP withdrawal. Sleep architecture, SDB indices, and subjective/objective daytime function were assessed pretreatment, on CPAP therapy, and after CPAP withdrawal. Comparisons were made between pretreatment and CPAP withdrawal for the entire group, and for subgroups of mild/moderate (AHI4% < 30/h, n = 22) and severe (AHI4% > 30/h, n = 20) SDB. RESULTS: Overall, and for mild/moderate subjects, SDB indices returned to pretreatment values on CPAP withdrawal but with fewer apneas and more hypopneas/RERAs. For severe SDB, the event frequency (AI, AHI4%, and RDI) was lower and O desaturation was improved on CPAP withdrawal. Across SDB severity, sleep architecture showed lower %REM (15.6% vs 12.9%, P = 0.009) on the CPAP withdrawal compared to pretreatment. Stanford Sleepiness Score, MSLT, and PVT measures were not significantly different between pretreatment and CPAP withdrawal. CONCLUSIONS: Over a wide range of SDB severity CPAP withdrawal results in recurrence of SDB, albeit with less severe O desaturation. Subjective/objective daytime function returned to pretreatment levels. Sleep architecture changes on CPAP withdrawal (acute SDB) may reflect reduced sleep pressure compared to pretreatment chronic SDB. Our data suggest detrimental effects of even brief withdrawal of CPAP in subjects with both mild and severe OSAHS. CITATION: Young LR; Taxin ZH; Norman RG; Walsleben JA; Rapoport DM; Ayappa I. Response to CPAP withdrawal in patients with mild versus severe obstructive sleep apnea/hypopnea syndrome. 2013;36(3):405-412.

MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management.

Introduction: During sleep studies, pulse oximetry using forehead relectance (R-ox) may have advantages over transmittance inger oximetry (T-ox) because of its ease of application. R-ox has been shown to be accurate and sensitive overall, but may be more subject to artifact from motion and changes in pressure on the sensor than T-ox. The purpose of the present study was to evaluate the signal loss of these two technologies using two commercially available devices used for home sleep testing of sleep-disordered breathing. Methods: We analyzed consecutive home studies performed in a cohort of 128 subjects (38% M, age 69+8 years, BMI 26.2+5.4kg/m², 267 nights of data) who used the ARES Unicorder (with R-ox) for 1-3 nights as part of a research study and 50 additional subjects (72% M, age 46+12 years, BMI 27.5+5.0kg/m², 50 nights of data) who used a Compumedics Somte (with T-ox) for one night as part of their clinical workup. The oximetry signal for each night was reviewed and oximet ry signal loss (%loss) was tabulated using automated detection followed by manual review. %loss between groups was compared by Mann-Whitney Rank Sum Test and Kolmogorov-Smirnov (KS-test). Results: In R-ox, TIB was 13.6+3.0 hr (over 2 nights); RDI was 24.5+15.2/hr. In T-ox, TIB was 7.6+1.0 hrs (1 night); RDI was 18.9+16.9/ hr. Overall, we could not show a signiicant difference for %loss between the two devices (%loss R-ox vs T-ox: median= 2.2% vs 3.1%; 25th %ile= 0% vs 0%; 75th %=13.7% vs 17.7%, p=ns by both statistical tests). In particular, there was no signiicant difference in the proportion of studies with <10% signal loss ("acceptable") between R-ox and T-ox (66% vs 68%). The two technologies also had similar proportion of studies with >40% signal loss (8% vs 8%). However, in the studies with 10- 40% loss (27% of R-ox and 24% of T-ox) there was signiicantly greater %loss in the R-ox studies (median =20% vs 15%, p=0.02 for rank-sum, p=0.004 KS-test). Conclusion: Overall, our data show equal num!

Introduction: Our previous work in cognitively normal elderly shows sleep-disordered breathing (S

Introduction: Sleep is important for memory, and various parameters of sleep may affect consolidation of spatial memory speciically. Both hippocampal electrophysiological evidence and behavioral performance evidence support roles for slow wave sleep (SWS) and REM sleep in spatial navigation. The role of REM is of particular clinical interest, as sleep disordered breathing (S

RATIONALE: Previous studies have shown that sleep-disordered breathing (S

Introduction: Effects of exercise on dynamic aspects of sleep have not been studied. We hypothesized that exercise alters dynamics of sleep stage transitions in healthy controls and patients with chronic fatigue syndrome (CFS). Methods: Sixteen female healthy controls (age: 38+9 years) and 17 female patients with CFS (age: 41+8 years) underwent overnight polysomnography (PSG) on a baseline night and on a night after their performance of a maximal exercise test. All subjects had an adaptation PSG to mitigate any irst night effect. We calculated transition probabilities and rates between sleep stages (waking, rapid eye movement [REM] sleep, N1, N2 and N3) and cumulative duration distributions of each sleep stage and sleep as a whole. Results: After exercise, healthy controls showed a signiicantly greater probability of transition from N1 to N2 and a lower rate of transition from N1 to wake than at baseline; CFS patients showed a signiicantly greater probability of transition from N2 to N3 and a lower rate of transition from N2 to N1. For both groups, these indings suggest there is improved quality of sleep after exercise. Continuity of sleep in the controls improved after exercise, while CFS patients had less continuous N1 and more continuous REM sleep. Despite their improvement in overall quality of sleep after exercise, CFS patients had a signiicantly greater probability and rate of transition from REM to wake compared to healthy controls. Conclusion: Exercise promotes transitions to deeper sleep stages for both healthy controls and CFS patients, but CFS patients showed coexisting sleep disruption and more fatigue. While exercise had positive effects on dynamic sleep morphology in both healthy controls and CFS patients, CFS patients may not fully normalize their sleep with exercise alone