Sleep Breathing Flow Characteristics as a Sign for the Detection of Wakefulness in Patients with Sleep Apnea

Abstract

Background: To improve the performance of simplified sleep studies, it is essential to properly estimate the sleep time. Objectives: Our aim is to estimate sleep efficiency on the basis of flow breathing signal characteristics. Methods: Twenty subjects with sleep apnea-hypopnea syndrome diagnosed by polysomnography were studied. A characteristic pattern of flow signal defined our criteria for wakefulness and sleep. Sleep was analyzed in 2 different runs: (1) in the usual manner (neurological and respiratory variables), and (2) only the nasal cannula flow signal was displayed on the computer screen and the sleep and wakefulness periods were scored according to our criteria. At the end of the scoring process, all the signals were displayed on the screen to analyze the concordance. Results: Three thousand and sixty-nine screens were analyzed. The polysomnography sleep efficiency measured was 80.8%. The estimated sleep efficiency measured by nasal prongs was 78.9%. The detection and concordance of wakefulness had a sensitivity of 58.7%, a specificity of 96.4%, a positive predictive value of 81.3% and a negative predictive value of 89.6%. Conclusions: Our criteria for sleep and wakefulness based on airflow waveform morphology are a helpful parameter for estimating sleep efficiency in a simplified sleep study.

Atypical patterns in portable monitoring for sleep apnoea: features of nocturnal epilepsy?

“…However, breathing flow features for the detection of wakefulness, previously described in patients with OSAS [9,10], are different from the patterns described in our study, which were characterised by an atypical, repetitive and stereotyped morphology. In addition, the lack of EEG channels and video control in portable monitoring cannot allow scoring of EDs and their correlation with paroxysmal motor attacks.…”

“…Only recordings showing repeated, time-limited, stereotyped polygraphic patterns recurring throughout the night, but with an apnoea/hypopnoea index (AHI) ,5 events?h -1 , were selected for investigation. No respiratory patterns analysed met the sleep breathing flow characteristics for detection of wakefulness in patients with OSAS [9,10]. Periodic limb movement (PLM) disorder was diagnosed for a PLM index o15 events?h -1 [1].…”

Management of Sleep Apnea without High Pretest Probability or with Comorbidities by Three Nights of Portable Sleep Monitoring

“…The PM time considered for scoring (PM scoring time) was defined as recording time minus the erratic breathing periods according to previously validated criteria. 17 Mean values were obtained for the 3 nights of PM. If one study was considered not to be valid, this was removed and the mean values were obtained from the other 2 nights with PM.…”

“…One of these is the performance of type 3 portable sleep monitoring system at home (PM). [12][13][14][15][16][17][18][19][20] However, this simplified procedure has only been demonstrated as being useful in patients with a high pretest probability of OSA. 12,14,18,20 In patients without high pretest probability it is not recommended, mainly because of a lack of analysis of sleep efficiency and the number of arousals, 21,22 variability in the apnea-hypopnea index (AHI), 15,16 or even the first-night effect.…”

Automatic CPAP Performance in Patients with Sleep Apnea Plus COPD

“…In Spain and the USA, the population of 30 to 70 years old, the prevalence of sleep-disorder breathing at apnea-hypopnea index (AHI) of ≥10 is 25-32% and the SAHS (AHI ≥10 plus excessive daytime sleepiness) prevalence is estimated in 3% to 3.4% (1). Overnight full polysomnography (PSG) is the gold standard for diagnosis and treatment, although simplifi ed alternative methods are very useful in a large percentage of patients and studies (2)(3)(4)(5)(6)(7).…”