Overnight Pulse Oximetry Research Articles

Utility of overnight pulse oximetry and heart rate variability analysis to screen for sleep-disordered breathing in chronic heart failure

BackgroundSleep-disordered breathing (SDB) is under diagnosed in chronic heart failure (CHF). Screening with simple monitors may increase detection of SDB in a cardiology setting. This study aimed to evaluate the...

P4‐275: High prevalence of nocturnal hypoxia in a dementia cohort

Chronic nocturnal hypoxia may be an important, but overlooked cause of neurovascular dysfunction and eventual neuronal cell death, the final common pathway of which is clinical dementia. As early as 1985, a small prospective study found sleep apnea (AHI 3 5) in 42.9% of demented patients compared with 4.3% of controls (p<.01). A more recent study demonstrated that elderly women with sleep-disordered breathing were at a significantly higher risk of developing MCI or dementia. To establish the prevalence of hypoxia in a heterogeneous group of cognitively impaired patients, we assessed patients seen in a non-academic dementia practice with resting and ambulatory pulse oximetry as well as nocturnal pulse oximetry. The medical records of 357 patients seen in a specialized dementia practice between October 2009 and October 2010 received physical examination, a comprehensive laboratory workup, neuroimaging, overnight pulse oximetry and standard neurocognitive assessments, including the Memory Orientation Screening Test (MOST). The mean age was 77.1 (±9.1), with a mean 13.1 (± 2.8) years of education. More than 90% were Caucasian and 66% were female. Within this sample, 66.7% had MOST scores falling in the range of dementia, 22.7% had likely MCI and 10.6% had cognitively normal scores, but were complaining of cognitive problems. Clinical levels of hypoxia were present in 227 or 63.6% of the sample based on overnight pulse oximetry. We found a much larger percentage of cognitively impaired patients suffering from nocturnal hypoxia than was previously suspected. Since one third of older Americans suffer from either MCI or clinical dementia, our obtained 63.6% prevalence of hypoxia could translate to 8 million Medicare patients with sleep-disordered breathing. The very large percentage of cognitively impaired patients with significant desaturations during sleep is consistent with recent research that implicates hypoxia as a precipitating or exacerbating factor in neurovascular dysfunction and the formation of beta-amyloid plaque in Alzheimer's disease and vascular dementia. While correlation does not imply causation, this finding continues to raise the possibility that interventions which improve or correct hypoxia may improve cognitive outcomes for patients already being treated with standard dementia medications.

Cephalometric Evaluation of Airway Changes Following Mandibular Distraction in Patients with Nocturnal Desaturations During Sleep Secondary to TMJ Ankylosis

The objective of this study was to cephalometrically evaluate the changes in the oro-pharyngeal airway and its correlation to the clinical outcome following mandibular distraction in patients with sleep disordered breathing secondary to tempero-mandibular joint (TMJ) ankylosis. Five patients diagnosed as having nocturnal desaturations during sleep secondary to TMJ ankylosis were evaluated in this study. They were evaluated pre and post mandibular distraction using cephalometry, to determine changes in their oro-pharyngeal airway space and, upper and lower airway dimensions. An attempt was made to correlate these changes to the clinical outcome of the procedure by over-night pulse-oximetry. The patients showed a mean increase of 31.33% in the oro-pharyngeal airway space with a 3.8% increase in the oxygen saturation levels. The change in the airway space dimensions and area was directly proportional to the oxygen saturation observed in the patients. The patients in this series did not show a very high apnoea hypopnoea index but had a compromised airway which resulted in sub-optimal sleep patterns. Mandibular distraction in these patients not only improved their esthetics but also proved to aid their functional rehabilitation by significantly increasing their oro-pharyngeal space and reducing their sleep disturbances.

P138 Evaluation of the need for a comprehensive assessment of lung function pre operatively in the morbidly obese

Introduction and ObjectivesChronic morbid obesity has been shown to impinge on normal respiratory function and can ultimately result in respiratory failure. Lee et al (2010) concluded that a more physiological...

The use of overnight pulse oximetry for obstructive sleep apnoea in a resource poor setting in Sri Lanka

The Journal of the Ceylon College of Physicians (JCCP) is a peer-reviewed, open access journal published bi-annually by the Ceylon College of Physicians (CCP) in the last week of June and December.The objective of the Journal is to promote good clinical practice and influence policy making across the medical world through publication of original research and peer reviewed articles on current issues and to foster responsible and balanced debate on issues that affect medicine and health care in Sri Lanka. Contributions to the JCCP reflect its national and multidisciplinary readership and include current thinking across a range of medical specialties.

2. Sleep-disordered breathing in heart failure; developing an evidence-based screening protocol

Over six million individuals in the United States are diagnosed with Heart Failure (HF). Recent data indicates at least 50% and up to 80% of HF patients have sleep-disordered breathing (SDB) and are largely undiagnosed. HF and SDB have similar symptoms such as nocturnal dyspnea, daytime sleepiness, and fatigue, which make subjective reporting instruments such as the Epworth Sleepiness Scale (ESS) less reliable. Untreated sleep apnea creates a perpetual cycle of stress on the cardiovascular system and predisposes HF patients to an increased risk for disease progression. The American College of Cardiology, American Heart Association, as well as the Heart Failure Society of America recommend screening for SDB. Although, the gold standard of diagnosing SDB is polysomnography no consensus on the best screening tool exists. Recent evidence has shown overnight pulse oximetry is a sensitive and specific tool for screening SDB in patients with HF. It is also economical, given that the Center for Medicare Services rate for overnight pulse oximetry is $29.57.

Associations between alcohol consumption and sleep-disordered breathing among Japanese women

The associations between alcohol consumption and sleep-disordered breathing in women are uncertain. We conducted a cross-sectional study of 3113 women aged 30-69 years. The 3% oxygen desaturation index (3% ODI), based on overnight pulse oximetry findings, was selected as an indicator of sleep-disordered breathing. 3% ODI frequencies of ≥5 were higher for drinking women with ethanol intakes of ≥23.0 g/d than for never drinkers: the respective multivariable odds ratios and 95% confidence intervals was 1.8(1.0-3.4). The corresponding odds ratio was 3.0(1.6-5.8) for habitual snoring. The associations of ethanol intakes of ≥23.0 g/d with 3% ODI ≥ 5 was more evident among women with BMI <23.0 kg/m(2) (median) than those with higher BMI but did not vary by habitual snoring. The multivariable odds ratios of 3%ODI ≥ 5 for women with ethanol intakes of ≥23.0 g/d versus never drinkers were 2.7(1.0-6.7) for lower BMI and 1.5(0.6-3.3) for higher BMI and the corresponding odds ratio were 2.8(1.6-7.2) and 3.2(1.3-7.9) for habitual snoring, respectively. Alcohol consumption was associated with higher prevalence of sleep-disordered breathing among Japanese women.

Overnight Pulse Oximetry Is a Useful Tool To Screen for Sleep Apnea in Patients Admitted With Acute Decompensated Heart Failure

Overnight Pulse Oximetry Is a Useful Tool To Screen for Sleep Apnea in Patients Admitted With Acute Decompensated Heart Failure

Alcohol Consumption Before Sleep Is Associated With Severity of Sleep‐Disordered Breathing Among Professional Japanese Truck Drivers

Alcohol consumption as well as overweight is known to aggravate the severity of sleep-disordered breathing (SDB), but little is known about alcohol consumption in truck drivers. The aim of this study was to examine the relationship between alcohol consumption and SDB among truck drivers. We conducted a cross-sectional study of 1,465 men aged 20-69 years who were registered with the Japanese Trucking Association. The 3% oxygen desaturation index (3%ODI) was selected as an indicator of SDB, representing the number of desaturation events per hour of recording time in which blood oxygen fell by > or =3% based on overnight pulse-oximetry. Participants completed a self-administered questionnaire including alcohol consumption on the same night for SDB assessment. The prevalence of 3%ODI > or =5, > or =10, and > or =15/h was 25.4%, 11.1%, and 6.6% respectively. The multivariable odds ratios (OR) of 3%ODI > or = 10/h were 1.5(0.9-2.5) for 0.5 to <1.0 g of alcohol intake/kg and 3.4(1.8-6.6) for > or =1.0 g of alcohol intake/kg compared with non-drinkers. Similar associations with alcohol consumption were observed for 3%ODI > or =5 and > or =15/h. The relation between alcohol consumption (> or =1.0 g of alcohol intake/kg) and 3%ODI > or = 10/h tended to be more evident among men with body mass index (BMI) <23.4 kg/m(2) than those with BMI >or = 23.4 kg/m(2) [11.4 (3.2-41) vs. 1.2 (0.6-2.7), p = 0.18 for interaction]. A similar trend was observed for 3%ODI > or= 5/h. The prevalence of undiagnosed SDB and the significant association of alcohol consumption with SDB severity emphasize the need for SDB screening and alcohol modification as well as weight control to prevent and control SDB among truck drivers.

Variations in Physician Interpretation of Overnight Pulse Oximetry Monitoring

Overnight pulse oximetry is commonly used for hypoxemia evaluation in patients with COPD and sleep-disordered breathing. There is little information regarding its impact on physician decision making, and therefore an important measure of its clinical utility is untested and unknown. The aim of this study was to describe physician interpretation, use, and opinions regarding overnight pulse oximetry. Forty-one pulmonary physicians and fellows participated in structured interviews consisting of three oximetry record interpretations, oral responses to a standard question set, and a questionnaire. Qualitative data were analyzed using an open coding process. Quantitative data were assessed for distributions. Four measures were consistently used by the majority of physicians in record interpretation: background information, arterial oxygen saturation measured by pulse oximetry (Spo(2)) waveform and pattern, and time spent with Spo(2) < 90%. An additional 10 measures were consistently used by 5 to 46% of physicians. No interpretation generated a recommendation with > 60% consensus. There was a wide range of opinions on important matters related to this test, including test utility, indications, variables considered most important for interpretation, and criteria for nocturnal oxygen prescription. Forty-one physicians provided 35 different opinions on when nocturnal supplemental oxygen should be initiated. The variation in physician interpretation, use, and opinions regarding overnight pulse oximetry calls into question its clinical utility and underscores a need for standardization of presentation, training, and interpretation.

Health outcome measurements in children with sleep disordered breathing

To validate the Child Health Questionnaire, measure quality of life in children with obstructive sleep apnoea and assess the impact of surgery. The primary carer of a consecutive series of 42 patients with sleep disordered breathing referred to a paediatric otolaryngology clinic completed the Child Health Questionnaire (version PF 28). Questionnaires were analysed for data quality and completeness, item/scale correlation, internal consistency and discriminant validity, interscale correlation and reliability. Following overnight pulse oximetry 37 children were diagnosed with obstructive sleep apnoea and underwent adenotonsillectomy. Child Health Questionnaire Physical Functioning 28 demonstrated excellent measuring characteristics in our population. Compared with normative data, children with obstructive sleep apnoea and their carers suffer a significant quality of life deficit, involving 10 of 13 subscales of the Child Health Questionnaire. This was most prominent in parental emotional impact, general health perception and family activities. There was no correlation between the severity of obstructive sleep apnoea and quality of life indices. Following surgery, there was a significant improvement in all Child Health Questionnaire subscales, which became equivalent to healthy children. The Child Health Questionnaire Physical Functioning 28 is an accurate and reliable way of assessing the impact of obstructive sleep apnoea on the quality of life in children in Britain. This appears to be significant in most aspects of a child's life, but is fully reversed following surgery.

Utility of Approximate Entropy From Overnight Pulse Oximetry Data in the Diagnosis of the Obstructive Sleep Apnea Syndrome

Approximate entropy (ApEn) is a family of statistics introduced as a quantification of regularity in time series without any a priori knowledge about the system generating them. The aim of this preliminary study was to assess whether a time series analysis of arterial oxygen saturation (SaO2) signals from overnight pulse oximetry by means of ApEn could yield essential information on the diagnosis of obstructive sleep apnea (OSA) syndrome. We analyzed SaO2 signals from 187 subjects: 111 with a positive diagnosis of OSA and 76 with a negative diagnosis of OSA. We divided our data in a training set (44 patients with OSA Positive and 30 patients with OSA Negative) and a test set (67 patients with OSA Positive and 46 patients with OSA Negative). The training set was used for algorithm development and optimum threshold selection. Results showed that recurrence of apnea events in patients with OSA determined a significant increase in ApEn values. This method was assessed prospectively using the test dataset, where we obtained 82.09% sensitivity and 86.96% specificity. We conclude that ApEn analysis of SaO2 from pulse oximetric recording could be useful in the study of OSA.

Ventilatory assistance in patients with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) leads to progressive muscle weakness, causing respiratory failure 1, 2. Untreated patients die at <25 yrs of age, and the mean age of death in the 1960s was 15 yrs. The introduction of mechanical ventilation has improved survival compared with historical controls 1–3. This finding has led to general agreement that noninvasive ventilation prolongs life in patients with DMD, although no controlled studies have been performed to confirm this hypothesis 4. Noninvasive mechanical ventilation is initially offered at night to treat sleep-related breathing disorders and hypoventilation, which are common in patients with DMD 5, 6. Breathing during sleep should be evaluated by polysomnography with continuous CO2 monitoring 7, or by continuous CO2 monitoring alone if polysomnography is not available. Overnight pulse oximetry combined with an early-morning arterial blood gas measurement (to detect a base excess) may also be used to monitor nocturnal ventilation. As the disease progresses, hypoventilation starts to occur during the daytime, and additional daytime ventilation is offered 4. When noninvasive mechanical ventilation is inadequately effective, poorly tolerated or not feasible owing to …

Efficacy of overnight pulse oximetry as a screening test for sleep-disordered breathing

Efficacy of overnight pulse oximetry as a screening test for sleep-disordered breathing

Unattended home sleep studies for the evaluation of suspected obstructive sleep apnoea syndrome in children

Children suspected of obstructive sleep apnoea syndrome (OSAS) are traditionally investigated in hospital with overnight sleep studies, and single-channel pulse oximetry is the commonest form of initial study. A prospective study was conducted comparing unsupervised sleep studies, using a Nellcor N-395 pulse oximeter, performed in hospital and at home. Two hundred and eleven patient studies were completed in 18 months, 158 in hospital and 53 at home. The median age of patients was four years in both groups. The mean study duration was 9 h 5 min in hospital and 9 h 12 min at home (P = 0.75). The mean time in pulse search was 0.4% (SD = 0.7) in hospital and 0.2% (SD = 0.4) at home (P = 0.008). The number of failed studies was 96 of 254 (38%) in hospital and three of 56 (5%) at home (P < 0.001). Overall, 149 hospital bed days were saved (at pounds 690 per bed day), representing pounds 68,540 saved annually. The results show that unattended home sleep studies in the form of overnight pulse oximetry can be performed to a standard better than hospital studies, where local community nursing facilities exist.

Prediction of the Apnea-Hypopnea Index From Overnight Pulse Oximetry

s: To compare the relative usefulness of the different indexes derived from pulse oximetry in the diagnosis of obstructive sleep apnea (OSA), and to determine if a combination of these indexes improves the prediction of the apnea-hypopnea index (AHI) measured by polysomnography. Prediction model developed from 224 patients, validated prospectively in 101 patients from the same center (group 1) and in 191 patients from a different sleep center (group 2). Two independent sleep clinics run by university sleep specialists. Patients who underwent polysomnography for suspicion of OSA. The following indexes were calculated from pulse oximetry recordings performed simultaneously during polysomnography: (1) Delta index, the average of the absolute differences of oxygen saturation between successive 12-s intervals; (2) desaturation events per hour to 2%, 3%, and 4% levels; and (3) cumulative time spent below 90%, 88%, 86%, 84%, 82%, and 80% saturation. The best predictor was the Delta index, although desaturation events provided similar levels of diagnostic accuracy. An aggregation of multivariate models using combination of indexes reduced the prediction error (r(2) = 0.70) significantly (p < 0.05) compared to using the Delta index alone (r(2) = 0.60). The proportion of subjects from the validation groups within 95% confidence interval (CI) of the derivation group was 90% (95% CI, 83 to 95%) and 91% (95% CI, 86 to 95%) for groups 1 and 2, respectively. The overall likelihood ratios for the aggregated model in all patient groups were 4.2 (95% CI, 3.3 to 15.3), 3.4 (95% CI, 2.7 to 4.3), 3.0 (95% CI, 2.2 to 4.1), and 6.7 (95% CI, 4.9 to 9.2) for normal (AHI < 5/h), mild (AHI 5 to < 15/h), moderate (AHI 15 to < 30/h), and severe (AHI > or = 30/h) disease, respectively. The Delta index and oxygen desaturation indexes provided similar levels of diagnostic accuracy. The combination of indexes improved the precision of the predicted AHI and may offer a potentially simpler alternative to polysomnography.

Sleep-Related Breathing Disorders and Rehabilitation Outcome of Stroke Patients

Sleep-related breathing disorder (SRBD) is more prevalent in stroke patients than in age- and sex-matched controls, but the relationship between SRBD, functional levels at admission, and subsequent recovery is unclear. We evaluated patients after a first stroke to determine the prevalence of SRBD and the influence of SRBD on the recovery of discharge functional status after a rehabilitation program. In a prospective study, 30 stroke patients were studied by continuous overnight pulse oximetry during sleep for the presence of desaturation events (fall of arterial saturation of > 4% from the baseline). The Respiratory Disturbance Index was defined as number of desaturations per hour of sleep. Functional assessment was done at admission using the FIM instrument. The patients were asked about total hours of sleep and the presence or absence of habitual snoring before and after the stroke. The outcome measure at discharge was the FIM score. On linear regression, after including the FIM score at admission, in the model, the Respiratory Disturbance Index score was negatively correlated with the FIM gain (coefficient, -0.635 +/- 0.27; P = 0.025), and together, the variables explained 20.9% of the total variance (adjusted r2). All patients with an admission FIM score of > or = 70 (only mild functional impairment) had a good outcome (FIM score of > 100 at discharge). However, only two of six of those with FIM scores of < 70 with SRBD (defined as a Respiratory Disturbance Index score of > 10) had significant improvement (> or = 30 points), whereas this occurred in seven of nine of those without SRBD (prevalence ratio, 0.43; 95% confidence interval, 0.13-1.40; P = 0.085) Even after adjusting for the admission functional status, the presence of hypoxic events during sleep predicts a poorer recovery, especially in stroke patients with poor function at admission.

Home Overnight Pulse Oximetry in Patients With COPD: More Than One Recording May Be Needed

Home overnight pulse oximetry (OPO) is used to assess nocturnal desaturation in patients with COPD, but the current practice of relying on one recording has not been studied. We assessed the variability of nocturnal desaturation in patients with COPD between nights, as measured by home OPO. Study subjects attended for clinical evaluation, spirometry, and arterial blood gas analysis. OPO was prospectively completed at home on 2 consecutive nights (study night 1 [N1] and study night 2 [N2]) and repeated at 3 weeks (study night 3 [N3]). Respiratory Services, Green Lane Hospital, Auckland, New Zealand. Twenty-six patients with clinically stable COPD (mean age, 69.3 years [SD, 6.9]; FEV(1), 28.6% predicted [SD, 10.6]; PO(2), 71.3 mm Hg [SD, 9.8]). Patients with asthma or clinical evidence of obstructive sleep apnea were excluded. Mean nocturnal saturation (MNS) and time spent with saturation below 90% (TB90%) were calculated for N1, N2, and N3. Group mean recording length, MNS, and TB90% were similar for each night. Little variation in MNS was seen between nights (N1 and N2 mean difference, 1.31%; N2 and N3, 1.26%; N1 and N3, 1.25%). Larger variation was seen between nights for TB90% (N1 and N2 mean difference, 17.46%; N2 and N3, 9.95%; N1 and N3, 14.05%). No factors were identified that predicted increased variability of TB90%. Using the current definition of "significant nocturnal desaturation" (TB90% > or = 30% of the night), 9 of 26 patients (34.6%) changed category between "desaturator" and "nondesaturator" from N1 to N2. Nocturnal desaturation in patients with COPD exhibits considerable night-to-night variability when measured by home OPO. A single home OPO recording may be insufficient for accurate assessment of nocturnal desaturation.

The utility of neural network in the diagnosis of Cheyne-Stokes respiration

The aim of this study was to design a diagnostic model to identify patients with Cheyne-Stokes respiration (CSR-CSA) based on indices of oximetric spectral analysis. A retrospective analysis of oximetric recordings of 213 sleep studies conducted over a one-year period at a Veterans Affairs medical facility was performed. A probabilistic neural network (PNN) was developed from salient features of the oximetric spectral analysis, desaturation events and the delta index. A fivefold cross-validation was used to assess the accuracy of the neural network in identifying CSR-CSA. When compared to overnight polysomnography, the PNN achieved a sensitivity of 100% (95% confidence interval [CI] 85%-100%) and a specificity of 99% (95% 97%-100%) with a corresponding area under the curve of 99% (95% CI 99%-100%). When combined with overnight pulse oximetry, PNN offers an accurate and easily applicable tool to detect CSR-CSA.

Overnight Pulse Oximetry in Nursing Home Residents with Behavior Problems: Case Reports

Sleep-related hypoxia is common in nursing home residents and may present as delirium, anxiety, agitation, or behavior problems as well as polycythemia, or it may exacerbate hypertension and/or congestive heart failure. 1 Strollo Jr, PJ Rogers RM Obstructive sleep apnea. N Engl J Med. 1996; 334: 99-104 Crossref PubMed Scopus (553) Google Scholar , 2 Drinka PJ Jochen AL Cuisinier M et al. Polycythemia as a complication of testosterone replacement therapy in nursing home men with low testosterone levels. J Am Geriatr Soc. 1995; 43: 899-901 Crossref PubMed Scopus (83) Google Scholar Its mechanisms include chronic cardiopulmonary disease, sleep hypopnea or apnea syndromes (obstructive and central), pulmonary edema with nocturnal resorption of peripheral edema, and dependency-related small airway closure with continued perfusion of nonventilated alveoli. Sleep-related respiratory disorders are more common in individuals with dementia and may be exacerbated by sedatives such as benzodiazepines or metabolic abnormalities such as end-stage renal disease. 3 Ancoli-Israel S Epidemiology of sleep disorders. Clin Geriatr Med. 1989; 5: 347-362 PubMed Google Scholar , 4 Ancoli-Israel S Klauber MR Butters N et al. Dementia in institutionalized elderly: Relation to sleep apnea. J Am Geriatr Soc. 1991; 39: 258-263 PubMed Google Scholar , 5 Mant A Saunders NA Eyland AE et al. Sleep-related respiratory disturbance and dementia in elderly females. J Gerontol. 1988; 43: M140-M144 Crossref PubMed Scopus (28) Google Scholar , 6 Guilleminault C Silvestri R Mondini S Coburn S Aging and sleep apnea: Action of benzodiazepine, acetazolamide, alcohol, and sleep deprivation in a healthy elderly group. J Gerontol. 1984; 39: 655-661 Crossref PubMed Scopus (76) Google Scholar , 7 Hanly PJ Pierratos A Improvement of sleep apnea in patients with chronic renal failure who undergo nocturnal hemodialysis. N Engl J Med. 2001; 344: 102-107 Crossref PubMed Scopus (473) Google Scholar