Analysis of nocturnal desaturation waveforms using algorithms in patients with idiopathic pulmonary fibrosis

Abstract Purpose Sleep-disordered breathing is recognized as a comorbidity in patients with idiopathic pulmonary fibrosis (IPF). Among them, nocturnal hypoxemia has been reported to be associated with poor prognosis and disease progression. We developed a diagnostic algorithm to classify nocturnal desaturation from percutaneous oxygen saturation (SpO2) waveform patterns: sustained pattern, periodic pattern, and intermittent pattern. We then investigated the prevalence of nocturnal desaturation and the association between the waveform patterns of nocturnal desaturation and clinical findings of patients with IPF. Methods We prospectively enrolled patients with IPF from seven general hospitals between April 2017 and March 2020 and measured nocturnal SpO2 and nasal airflow by using a home sleep apnea test. An algorithm was used to classify the types of nocturnal desaturation. We evaluated the association between sleep or clinical parameters and each waveform pattern of nocturnal desaturation. Results Among 60 patients (47 men) who met the eligibility criteria, there were 3 cases with the sustained pattern, 49 cases with the periodic pattern, and 41 cases with the intermittent pattern. Lowest SpO2 during sleep and total sleep time spent with SpO2 < 90% were associated with the sustained pattern, and apnea–hypopnea index was associated with the intermittent pattern. Conclusion We demonstrated the prevalence of each waveform and association between each waveform and sleep parameters in patients with IPF. This classification algorithm may be useful to predict the degree of hypoxemia or the complication of obstructive sleep apnea.

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0567 Hypoxic Burden and Apnea-Hypopnea Duration in Patients with Positional Obstructive Sleep Apnea

SLEEP ◽

10.1093/sleep/zsaa056.564 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A217-A218

Author(s):

J A Ramzy ◽

R Rengan ◽

M Mandal ◽

S Rani ◽

M E Vega Sanchez ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Total Sleep Time ◽

Sleep Time ◽

Apnea Hypopnea Index ◽

Apnea Test ◽

Positional Obstructive Sleep Apnea ◽

Obstructive Sleep ◽

Respiratory Event ◽

The Mean

Abstract Introduction Recently, the measurement of the hypoxic burden and apnea-hypopnea duration has been shown to correlate with mortality in patients with obstructive sleep apnea (OSA). We hypothesized that in patients with mild positional OSA (apnea-hypopnea index [AHI] < 5 events/hr in the non-supine position) the hypoxic burden would be increased and apnea-hypopnea duration shortened and similar to patients with non-positional OSA. Methods Fourteen patients with positional OSA and 24 patients non-positional OSA with similar severity of OSA based on the respiratory event index (REI) were included. All patients had a home sleep apnea test for suspected OSA. The hypoxic burden was calculated by the multiplication of REI and the mean area under the desaturation curves. Results Thirty-eight patients [12 (35%) males, 50±12 yrs, BMI 35±7 kg/m2, Epworth Sleepiness Scale (ESS) 11±8, REI 10±3 events/hr, apnea-hypopnea duration 19±4 sec, mean SaO2 94±2%, lowest SaO2 79±8%, % total sleep time (TST) SaO2 < 90% 11±16%, hypoxic burden 30±17 %min/hr] completed the study. Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 < 90% 4±6%] had positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) and 24 patients had non-positional OSA [3 (13%) males, 52±10 yrs, BMI 38±7 kg/m2, ESS 12±9, REI 10±3 events/hr, mean SaO2 94±2%, lowest SaO2 77±9%, %TST SaO2 < 90% 14±19%]. The hypoxic burden was elevated in both the positional and non-positional OSA patients with no difference between the groups (26±19 %min/hr and 32±15 %min/hr, respectively, p=0.13). The apnea-hypopnea duration was similar in positional and non-positional OSA patients (20±3 sec and 18±4 sec, respectively, p=0.08 sec). Conclusion In patients with mild positional OSA the hypoxic burden, which has been associated with cardiovascular mortality, is elevated and similar to patients with non-positional OSA. Support None

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Altered K-complex morphology during sustained inspiratory airflow limitation is associated with next-day lapses in vigilance in obstructive sleep apnea

SLEEP ◽

10.1093/sleep/zsab010 ◽

2021 ◽

Author(s):

Ankit Parekh ◽

Korey Kam ◽

Anna E Mullins ◽

Bresne Castillo ◽

Asem Berkalieva ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Spectral Characteristics ◽

Sleep Time ◽

Airflow Limitation ◽

Apnea Hypopnea Index ◽

Complex Morphology ◽

Obstructive Sleep ◽

Inspiratory Airflow Limitation ◽

Psychomotor Vigilance

Abstract Study Objectives Determine if changes in K-complexes associated with sustained inspiratory airflow limitation (SIFL) during N2 sleep are associated with next-day vigilance and objective sleepiness. Methods Data from thirty subjects with moderate-to-severe obstructive sleep apnea who completed three in-lab polysomnograms: diagnostic, on therapeutic continuous positive airway pressure (CPAP), and on suboptimal CPAP (4 cmH2O below optimal titrated CPAP level) were analyzed. Four 20-min psychomotor vigilance tests (PVT) were performed after each PSG, every 2 h. Changes in the proportion of spontaneous K-complexes and spectral characteristics surrounding K-complexes were evaluated for K-complexes associated with both delta (∆SWAK), alpha (∆αK) frequencies. Results Suboptimal CPAP induced SIFL (14.7 (20.9) vs 2.9 (9.2); %total sleep time, p < 0.001) with a small increase in apnea–hypopnea index (AHI3A: 6.5 (7.7) vs 1.9 (2.3); p < 0.01) versus optimal CPAP. K-complex density (num./min of stage N2) was higher on suboptimal CPAP (0.97 ± 0.7 vs 0.65±0.5, #/min, mean ± SD, p < 0.01) above and beyond the effect of age, sex, AHI3A, and duration of SIFL. A decrease in ∆SWAK with suboptimal CPAP was associated with increased PVT lapses and explained 17% of additional variance in PVT lapses. Within-night during suboptimal CPAP K-complexes appeared to alternate between promoting sleep and as arousal surrogates. Electroencephalographic changes were not associated with objective sleepiness. Conclusions Sustained inspiratory airflow limitation is associated with altered K-complex morphology including the increased occurrence of K-complexes with bursts of alpha as arousal surrogates. These findings suggest that sustained inspiratory flow limitation may be associated with nonvisible sleep fragmentation and contribute to increased lapses in vigilance.

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474 Phenotyping of patients with Moderate to Severe OSA on Polysomnography after Negative Home Sleep Apnea Testing

SLEEP ◽

10.1093/sleep/zsab072.473 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A187-A187

Author(s):

Sarah Sarfraz ◽

Lindsay McCullough ◽

Henry Arantes ◽

Alejandra Lastra

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Flow Time ◽

Apnea Hypopnea Index ◽

Apnea Test ◽

Recording Time ◽

Time Flow ◽

Obstructive Sleep ◽

Severe Sleep Apnea ◽

Apnea Testing

Abstract Introduction Polysomnography (PSG) is the gold standard for the diagnosis of obstructive sleep apnea (OSA). Given cost, insurance restrictions and in some cases limited access to sleep center testing, the use of home based sleep apnea testing is becoming increasingly more common. A proportion of patients with technically adequate HSAT who are negative end up having significant disease on PSG. The characteristics of patients who are found to have moderate to severe sleep apnea on polysomnogram (PSG) after a negative home sleep apnea test (HSAT) are not known. We aim to phenotype these patients. Methods We conducted a retrospective chart review from March 2018 to February 2020. A total of 953 adult patients (18 years old and older) underwent HSAT, 248 tests resulted negative (apnea-hypopnea index <5/h). Out of the negative HSAT, 17 patients had moderate to severe obstructive sleep apnea on PSG. Those were included for analysis. Data on patient characteristics such as age, body mass index (BMI), gender, STOP-BANG, ESS and comorbidities was gathered. Respiratory disturbance index, recording time, flow time, oximetry time on HSAT was recorded. PSG recording time, baseline AHI, supine AHI and non-supine AHI were also noted. Technically inadequate HSAT were excluded from analysis. Results The percentage of patients with negative HSAT who were found to have moderate to severe sleep apnea on PSG and were included for analysis was 6.85% (n17). Mean age was 41 years. Mean BMI was 33 kg/m2. Common comorbidities were hypertension (29%), asthma (17.6 %), depression (17.6%), anxiety (11.7%) and reflux (5.9%). Average ESS was 11.7 and STOP-BANG was 3.8. The mean recording time was 477 minutes, flow time 391 minutes and oximetry time was 426 minutes on HSAT. Average PSG recording time was 433 minutes. Average AHI was 24 with supine being 33.2/h and non-supine 17.9/h. Conclusion A proportion of patients with negative HSAT have moderate to severe OSA on follow-up polysomnogram. These patients were young, with lower-class obesity, more positional OSA, and no associated complex comorbidities. Re-evaluation of current diagnostic algorithms and further research is needed to phenotype this at-risk group, as first-line PSG may be more cost-effective and efficient. Support (if any):

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Abstract TMP55: Polysomnographic and Sleep-related Variables Associated to Leukoaraiosis in Patients with Obstructive Sleep Apnea

Stroke ◽

10.1161/str.48.suppl_1.tmp55 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Kevin R Duque ◽

Brian Villafuerte ◽

Fiorella Adrianzen ◽

Rodrigo Zamudio ◽

Andrea Mendiola ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Logistic Regression ◽

Sleep Apnea ◽

Multinomial Logistic Regression ◽

Sleep Time ◽

Cross Sectional Study ◽

Apnea Hypopnea Index ◽

Cross Sectional ◽

Obstructive Sleep ◽

Medical Histories

Introduction: Obstructive sleep apnea (OSA) is a biological plausible risk factor for leukoaraiosis (LA). We tested the hypothesis that polysomnographic (PSG) and sleep-related variables are associated to LA in OSA patients. Methods: Cross-sectional study in which PSG records, medical histories and brain 1.5T MRI were collected from all consecutive patients who had attended a Sleep Medicine Center between 2009-2014. LA was graded from 0 to 9 with the ’Atherosclerosis Risk In Communities’ study scale. OSA was defined by The International Classification of Sleep Disorders, 2014, and its severity categorizing according to apnea-hypopnea index (AHI, <15 mild, 15 to <30 moderate, 30 to <45 severe and ≥45 very severe). A multinomial logistic regression was performed to describe the association between OSA severity and LA (divided into 2 groups: mild-to-moderate LA and non-to-minimal LA). The covariates for all regression models were age, gender, BMI, hypertension, ischemic stroke, myocardial infarction, diabetes and pack-year of smoking. Results: From 82 OSA patients (77% male; mean age 58±9 years, range 19-91), 54 (66%) had LA. Mild-to-moderate LA was found in 13 patients (8 mild and 5 moderate LA) and non-to-minimal LA in 69 (41 minimal and 28 non LA). Spearman’s correlation coefficient between AHI and LA grade was 0.41 (p<0.001). Furthermore, the higher OSA severity, the higher LA severity (p<0.001, for Jonckheere-Terpstra test for ordered alternatives). In the multinomial logistic regression model adjusted for cofounders, severe OSA patients had higher risk for mild or moderate LA (HR 12.8, 95% IC 1.2-141) compared to mild-to-moderate OSA patients. Additionally, self-reported habitual sleep duration from 7 to 9 hours (HR 0.36, 90% IC 0.14-0.90) and proportion of time in apnea/hypopnea over total sleep time (HR 1.04 for one unit increase, 90% IC 1.01-1.08) could be associated with the presence of LA (adjusted only for age and gender). In a multiple regression analysis with all the aforementioned variables, age (p=0.002), diabetes (p=0.003), and OSA severity (p=0.04) were predictors of the presence of LA. Conclusion: Patients with severe OSA had higher risk for mild to moderate LA when compared to patients with mild or moderate OSA.

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0610 Prevalence of Positional Obstructive Sleep Apnea Based on 3% Vs 4% Oxygen Desaturation Using Home Sleep Apnea Testing

SLEEP ◽

10.1093/sleep/zsaa056.607 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A233-A234

Author(s):

M Mandal ◽

R Rengan ◽

S Rani ◽

J Ramzy ◽

M Vega Sanchez ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Oxygen Desaturation ◽

Apnea Hypopnea Index ◽

Apnea Test ◽

Positional Obstructive Sleep Apnea ◽

Obstructive Sleep ◽

Respiratory Event ◽

Home Sleep Apnea Testing ◽

Definition Of

Abstract Introduction Approximately 30% of patient with obstructive sleep apnea (OSA) have positional OSA [non-supine apnea-hypopnea index (AHI) < 5 events/hr]. However, the prevalence is based on variable definitions for hypopneas related to the degree of oxygen desaturation. In addition, use of a home sleep apnea test (HSAT) to identify positional OSA is limited. We hypothesized that in patients evaluated with an HSAT, using a definition for hypopneas based on 4% compared to 3% oxygen desaturation will significantly decrease the percentage diagnosed with positional OSA. Methods Fourteen patients with positional OSA based on a non-supine respiratory event index (REI) < 5 events/hr were included. The initial diagnosis was determined based on a hypopnea definition of ≥ 3% oxygen desaturation. The studies were reanalyzed using a hypopnea definition of ≥ 4% oxygen desaturation. Results Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 < 90% 4±6%] were identified with positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) using a hypopneas definition of ≥ 3% oxygen desaturation. When reanalyzed using a hypopnea ≥ 4% oxygen desaturation there was a significant decrease in the REI to 7±2 events/hr (p<0.001). Three patients (21%) no longer were considered to have OSA. These patients were younger (32±14 vs. 50±11yrs, p=0.03) and had less severe OSA (REI 6±1 vs. 9±3 events/hr (p=0.04), but there was no difference in BMI (32±11 vs. 31±5 kg/m2, p=0.9) or mean and lowest SaO2 (96±0.4 vs. 94±2%, p=0.13, and 82±8 vs. 81±6%, p=0.9, respectively). Conclusion In patients with mild positional OSA, using a hypopnea definition of at least 4% vs. 3% oxygen desaturation on a HSAT will have a significant effect on the overall REI and often exclude patients who would otherwise be treated for OSA. Support None.

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0722 The Association Between Obstructive Sleep Apnea and Neurobehavioural Function in Men: A Large, Population-Based Cohort Study

SLEEP ◽

10.1093/sleep/zsaa056.718 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A274-A275

Author(s):

J L Parker ◽

R J Adams ◽

S L Appleton ◽

Y A Melaku ◽

A Vakulin

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Total Sleep Time ◽

Sleep Time ◽

Inspection Time ◽

Sleep Disruption ◽

Clinical Samples ◽

Apnea Hypopnea Index ◽

Cross Sectional ◽

Obstructive Sleep

Abstract Introduction Obstructive sleep apnea (OSA) is linked with impaired vigilance, attention, memory and executive function. However, this evidence largely comes from small experimental studies or larger studies in clinical samples and therefore the scope and magnitude of OSA driven neurobehavioural dysfunction in the general population remains unclear. This study aimed to examine the cross-sectional association between OSA and neurobehavioural function in a large community sample of men. Methods A total of 837 participants from the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study, a longitudinal cohort of men 40+ years, underwent full overnight polysomnography. Participants completed the inspection time (IT) test, mini-mental state examination (MMSE), Fuld object memory evaluation (FOME), and trail-making test (TMT) part A (TMT-A) and part B (TMT-B). Using regression models adjusted for multiple important covariates, we examined the association between neurobehavioural function scores, clinical metrics of OSA severity (Apnea-Hypopnea Index (AHI); percentage total sleep time with oxygen saturation <90% (TST90), and measures of sleep disruption (duration of rapid eye movement (REM) and non-REM (NREM) sleep; and total sleep time (TST). Results In multivariable linear regressions, greater TST was associated with worse IT scores (B=13.688, 95% CI [0.134, 27.241], P=0.048) and TMT-B scores (B=19.255, 95% CI [0.931, 37.578], P=0.040). In logistic regressions, greater TST was associated with better MMSE scores (Odds ratio [OR]=0.440, 95% CI [0.194, 0.997], P=0.049); and higher AHI was strongly associated with worse FOME scores in fully adjusted models (OR=1.358, 95% CI [1.252, 1.472], P<0.001). Conclusion The AHI and TST were positively, significantly associated with neurobehavioural function across different domains. This cross-sectional data shows that neurobehavioural function deficits in OSA are directly related to sleep and breathing disruptions. Future large prospective studies are needed to determine if OSA and sleep disruption predict future onset of neurobehavioural dysfunction and cognitive decline. Support National Health and Medical Research Council and the Adelaide Institute for Sleep Health.

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