Prospective Study of Nocturnal Desaturation in Patients Receiving Home Oxygen Therapy

Objective Nocturnal desaturation is common in patients with chronic respiratory disease and often worsens the prognosis. Therefore, it should be diagnosed accurately and appropriately treated. The aim of this study was to clarify the diversity of nocturnal desaturation. Methods We prospectively enrolled 58 outpatients diagnosed with chronic respiratory disease receiving home oxygen therapy and measured nocturnal SpO₂ using a portable oximeter. We classified nocturnal desaturation (3% decrease in SpO₂ from baseline) into three patterns: periodic pattern (desaturation duration of <655 seconds), sustained pattern (desaturation duration of ≥655 seconds), and intermittent pattern (desaturation and recovery of SpO₂ repeated with a cycle of several minutes). Results Nocturnal hypoxemia (SpO₂ ≤88% for more than 5 minutes) was found in 23.8% of patients. The percentage of patients with chronic obstructive pulmonary disease (COPD) was significantly higher in the nocturnal hypoxemia group than in the non-hypoxemia group (80% vs. 40.6%, p=0.03). Desaturation with a periodic pattern was found in 81% of patients, desaturation with a sustained pattern was found in 40.5% of patients, and desaturation with an intermittent pattern was found in 59.5% of patients. In patients with COPD, desaturation with a periodic pattern was found in 85.7%, desaturation with a sustained pattern was found in 47.6%, and desaturation with an intermittent pattern was found in 57.1%. Conclusion The SpO₂ waveform of nocturnal hypoxemia was able to be classified into three patterns. Suitable treatment for each pattern might improve the prognosis of these patients.     

Sleep-Disordered Breathing in Adults with Precapillary Pulmonary Hypertension: Prevalence and Predictors of Nocturnal Hypoxemia

Purpose

To evaluate the frequency of sleep-disordered breathing (SDB) and predictors of the presence of nocturnal desaturation in adults with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

Methods

Outpatients with a hemodynamic diagnosis of precapillary pulmonary hypertension who underwent portable polysomnography were evaluated. Diagnosis and severity of SDB were assessed using three well-established respiratory disturbance index (RDI) thresholds: 5.0/h, 15.0/h, and 30.0/h, while nocturnal hypoxemia was defined by the average oxygen saturation (SpO₂)?<?90%. Multiple linear regression analysis evaluated the potential relationships among explanatory variables with the dependent variable (average SpO₂ values), with comparisons based on the standardized regression coefficient (β). The R-squared (R²; coefficient of determination) was used to evaluate the goodness-of-fit measure for the linear regression model.

Results

Thirty-six adults were evaluated (69.4% females). The majority of the participants (75.0%) had SDB (26 with obstructive sleep apnea [OSA] and one with central sleep apnea [CSA]); while 50% of them had nocturnal hypoxemia. In the linear regression model (R²?=?0.391), the mean pulmonary artery pressure [mPAP] (β ? 0.668; p?=?0.030) emerged as the only independent parameter of the average SpO₂.

Conclusion

Our study found that the majority of the participants had some type of SDB with a marked predominance of OSA over CSA, while half of them had nocturnal desaturation. Neither clinical and hemodynamic parameters nor the RDI was a predictor of nocturnal desaturation, except for mPAP measured during a right heart catheterization, which emerged as the only independent and significant predictor of average SpO₂.

     

Analysis of the characteristics of sleep in patients with patent foramen ovale complicated with obstructive sleep apnea

Purpose

Analyzing sleep quality and sleep structure in patients with patent foramen ovale (PFO) complicated with obstructive sleep apnea (OSA) and the interaction between OSA and PFO in sleep.

Methods

We compared patients with PFO complicated with OSA, patients with simple PFO, and controls. Pittsburgh Sleep Quality Index was used to compare sleep quality and polysomnography was used to compare sleep structure of the three groups.

Results

Compared with the control group (n = 62), PFO with OSA (n = 48) and simple PFO (n = 61) groups had more frequent occurrence of poor sleep quality (χ² = 89.901; p < 0.001). These two groups also showed decreased sleep efficiency (p < 0.010), lower percentages of REM sleep, and reduced N3 sleep (p < 0.050). The N2 sleep was prolonged (p < 0.010). The nocturnal lowest SpO₂ was lower and the oxygen desaturation index was higher (p < 0.50). Compared with the simple PFO group, the poor sleep quality was more frequent in the PFO with OSA group; sleep latency (p < 0.001) was prolonged; wake after sleep onset (p < 0.001) and arousal times (p = 0.031) were increased; and sleep micro-arousal index (p = 0.037), periodic leg movement index (p = 0.024), and apnea hypopnea index (p < 0.001) were higher in the PFO with OSA group.

Conclusion

Patients with PFO and OSA have poor sleep quality with changes in sleep stage and high occurrence rate of sleep disorders. OSA further deteriorates sleep quality and alters sleep structure in patients with PFO.

     

Evening-to-morning blood pressure variations in snoring patients with and without obstructive sleep apnea.

This study was designed to test a hypothesis that patients with sleep apnea have higher blood pressure in the morning, following a night spent in apnea and hypoxemia, than in the evening. To accomplish this, we prospectively studied a set of 611 patients referred to our clinic because of suspicion of sleep apnea. All patients had full nocturnal polysomnography, including measurement of snoring. Blood pressure was measured in the evening, prior to onset of sleep, and in the morning, immediately on awakening. We found that patients without apnea and hypoxemia had lower blood pressure in the morning compared with the evening value, while patients with severe sleep apnea and hypoxemia had higher blood pressure in the morning; these evening-to-morning blood pressure differences, although statistically significant, were small, typically 1 to 4 mm Hg. Morning blood pressures were higher in patients with sleep apnea and hypoxemia than in nonapneic normoxic patients. However, this difference disappeared after the groups were matched for age and body mass index. We conclude that (1) patients with sleep apnea and nocturnal hypoxemia lose the expected morning dip in arterial blood pressure, and (2) age and body mass index are more important correlates of blood pressure than apnea and nocturnal oxygen desaturation. We speculate that the loss of evening-to-morning drop in blood pressure, if present over a long period of time, may lead to sustained elevations in arterial blood pressure frequently observed in patients with sleep apnea.     

Polysomnography‐derived sleep parameters as a determinant of nocturnal blood pressure profile in patients with obstructive sleep apnea

Obstructive sleep apnea causes blood pressure (BP) surges during sleep, which may lead to increased sleep‐onset cardiovascular events. The authors recently developed an oxygen‐triggered nocturnal BP monitoring system that initiates BP measurements when oxygen desaturation (SpO₂) falls below a variable threshold. The association between nocturnal BP parameters obtained by nocturnal BP monitoring and simultaneously examined polysomnography‐derived sleep parameters in 116 patients with obstructive sleep apnea (mean age 57.9 years, 85.3% men) was studied. In multivariable analysis with independent factors of age, body mass index, sex, and polysomnography‐derived measures (apnea‐hypopnea index, apnea index, arousal index, lowest SpO₂, and SpO₂ < 90%), apnea‐hypopnea index (β = .26, P = .02) and lowest SpO₂ (β = −.34, P < .001) were independent determinants of hypoxia‐peak systolic BP (SBP), defined as the maximum SBP value measured by nocturnal BP monitoring. Similarly, apnea‐hypopnea index (β = .21, P = .04) and lowest SpO₂ (β = −.49, P < .001) were independent determinants of nocturnal SBP surge, defined as the difference between the hypoxia‐peak SBP and the average of the SBP values within 30 minutes before and after the hypoxia‐peak SBP, measured by the fixed‐interval function in the manner of conventional ambulatory BP monitoring. In conclusion, in polysomnography‐derived parameters, lowest SpO₂, defined as the minimum SpO₂ value during sleep, is the strongest independent determinant of hypoxia‐peak SBP and nocturnal SBP surge measured by nocturnal BP monitoring. Our findings suggest that the severity of the decrease in SpO₂ and the frequency of such decreases would be important indicators to identify high‐risk patients who are likely to develop cardiovascular events specifically during sleep.     

Prevalence of masked and nocturnal hypertension in patients with obstructive sleep apnea syndrome

IntroductionObstructive sleep apnea (OSA) is considered as a risk factor for the development and worsening of compensation of arterial hypertension and other cardiovascular diseases. Prevalence of masked and nocturnal hypertension can have a significant negative impact on these patients and these prevalences are not well known.AimTo evaluate the prevalence of masked and nocturnal hypertension in patients with OSA.Materials and methodsIn this study, 97 (88 men) patients were enrolled, average age 53.9 ± 9.7 years. OSA was diagnosed with polysomnography and the continuous positive airway pressure therapy has been indicated according to current guidelines. Then were evaluated parameters of OSA (apnea-hypopnea index (AHI), oxygen desaturation index (ODI), % of sleep time <90% SpO₂, average night SpO₂). Patients also underwent physical examination including office blood pressure measurement, 24 h blood pressure monitoring (ABPM) and measurement of anthropometric parameters.ResultsFollowing average values were present in OSA patients (mean value and standard deviation): AHI 54.6 ± 22.7, ODI 58.3 ± 24, % of sleep time < 90% SpO₂ 35.4 ± 25.1, average night SpO₂ 88.8 ± 5. Masked hypertension was present in 55 (56.7%) patients, nocturnal hypertension in 79 (81.4%) patients. Arterial hypertension was appropriately compensated in only 15 (15.5%) patients. Results have not shown any statistically significant correlation between prevalence of nocturnal hypertension and AHI (p = 0.059), % of sleep time <90% SpO₂ (p = 0.516), average night SpO₂ (p = 0.167). ODI was significantly higher in patients with nocturnal hypertension (p = 0.002). No correlation between prevalence of masked hypertension and AHI (p = 0.841), ODI (p = 0.137), average night SpO₂ (p = 0.991) and % of sleep time <90% SpO₂ (p = 0.896) has been present.ConclusionThis study has demonstrated high prevalence of masked and nocturnal hypertension in patients with OSA, which can considerably increase risks of cardiovascular diseases in these patients.     

Angiotensin II receptor blocker irbesartan attenuates sleep apnea–induced cardiac apoptosis and enhances cardiac survival and Sirtuin 1 upregulation

Background

The purpose of this study was to investigate whether or not angiotensin II type 1 receptor blocker irbesartan (ARB) with a partial agonist of PPAR-γ could protect against chronic nocturnal intermittent hypoxia (CIH)–induced cardiac Fas/FasL-mediated to mitochondria-mediated apoptosis.

Methods

Sprague–Dawley rats were in a normoxic control group (CON-G), or rats were in a chronic nocturnal intermittent hypoxia group (HP-G, from 3 to 7% oxygen versus 21% oxygen per forty seconds cycle, nocturnally 8 h per day for 1 month), or rats were in a chronic nocturnal intermittent hypoxia group pretreated with ARB (50 mg/kg/day, S.C.) (ARB-HP-G). Echocardiography, H&E staining, TUNEL staining, and Western blotting were measured in the left ventricle.

Results

Hypoxia-induced SIRT1 degradation, Fas receptors, FADD, active caspase-8 and caspase-3 (Fas/FasL apoptotic pathway) and Bax, tBid, active caspase-9 and -3 (mitochondrial apoptotic pathway) and TUNEL-positive apoptosis were reduced in ARB-HP-G when compared with HP-G. IGF-I, IGF1 receptor, p-PI3k, p-Akt, Bcl2, and Bcl-XL (IGF1/PI3K/AKT pro-survival pathway) were increased in ARB-HP-G compared to HP-G.

Conclusions

Our findings suggest that the ARB may prevent cardiac Fas/FasL to mitochondrial apoptotic pathways and enhance cardiac IGF1/PI3K/AKT pro-survival pathway in the sleep apnea model associated with JNK de-activation and SIRT1 upregulation. ARB prevents chronic sleep apnea–enhanced cardiac apoptosis via enhancing survival pathways.

     

Serum levels of magnesium and their relationship with CRP in patients with OSA

Background

Low levels of magnesium (Mg) are associated with chronic inflammatory stress. Some animal studies have reported that a moderate deficiency of Mg, similar to that which occurs in humans, may increase inflammatory or oxidative stress stimulated by other factors, such as disrupted sleep or sleep deficiency.

Purpose

This cross-sectional study evaluated the relationship between serum levels of Mg and the inflammatory response in patients with a new diagnosis of obstructive sleep apnea (OSA).

Methods

This clinical, retrospective study registered 68 patients with newly diagnosed mild to severe OSA and 30 without OSA. The Apnea–Hypopnea Index (AHI), oxygen desaturation index (ODI), time until blood hemoglobin oxygen saturation <90 % (SpO₂ <90 %), and mean blood hemoglobin SpO₂ were measured. Serum levels of Mg, plasma C-reactive protein (CRP), and total sleep time (TST) by polysomnography were also measured.

Results

Mg levels were lower in patients with OSA than those in controls matched for age, sex, and body mass index (BMI). Patients with OSA had substantially higher plasma CRP concentrations than controls. A negative correlation was observed between the AHI and ODI and Mg levels. Significant differences in Mg and CRP levels were observed between patients with AHI scores of 5–15 and scores ≥30 based on OSA severity but independent of BMI. Furthermore, the AHI, ODI, TST <90 %, and mean SpO₂ significantly correlated with CRP. A significant negative correlation was observed between Mg and CRP levels (p < 0.0001).

Conclusion

Our results show that Mg levels changed depending on the presence and severity of OSA. Low levels were associated with a higher CRP concentration in patients with OSA.

     

Pulse oximetry saturation can predict prognosis of idiopathic pulmonary fibrosis

BackgroundIn Japan, the severity staging system for idiopathic pulmonary fibrosis (IPF) has been used to determine medical care subsidies. However, this system requires invasive procedures to measure arterial oxygen tension. Recently, noninvasive and simple measurements of oxygen saturation by pulse oximetry (SpO₂) have been used for severity assessments. We propose a pulse oximetry saturation (POS) staging system consisting of SpO₂ parameters to predict prognosis.MethodsWe developed four prototype staging systems based on SpO₂ at rest and desaturation, and adopted the system with the highest C-statistic as the POS staging system. The cutoff SpO₂ values at rest were 96% and 90%, and desaturation was defined as SpO₂ < 90% at the end of the 6-min-walk test.ResultsTwo-hundred and nineteen IPF patients were studied and the C-statistic values of models 1, 2, 3, and 4 were 0.633, 0.643, 0.630, and 0.673, respectively. We judged model 4 to be a superior POS staging system; it defined SpO₂ ≥ 96% at rest without desaturation as stage Ⅰ; SpO₂ ≥ 96% at rest with desaturation or SpO₂ 90%–95% at rest without desaturation as stage Ⅱ; and SpO₂ 90%–95% at rest with desaturation or SpO₂ < 90% at rest as stage Ⅲ. The hazard ratios of POS stage Ⅰ, Ⅱ, and Ⅲ were 1.00, 2.25, and 4.99, respectively. The C-statistic of the POS staging system produced from 1000 bootstrap samples was similar (0.673), suggesting good internal validation.ConclusionA noninvasive and simple POS staging system defined by SpO₂ can easily predict prognosis.     

Association Between the Severity of Nocturnal Hypoxia in Obstructive Sleep Apnea and Non-Alcoholic Fatty Liver Damage

Background:

Obstructive sleep apnea (OSA) is a major disease that can cause significant mortality and morbidity. Chronic intermittent hypoxia is a potential causal factor in the progression from fatty liver to nonalcoholic steatohepatitis.

Objectives:

This study evaluated the association between the degree of liver steatosis and severity of nocturnal hypoxia.

Patients and Methods:

In this study, between December 2011 and December 2013, patients with ultrasound-diagnosed NAFLD evaluated by standart polysomnography were subsequentally recorded. Patients with alcohol use, viral hepatitis and other chronic liver diseases were excluded. We analyzed polysomnographic parameters, steatosis level and severity of obstructive sleep apnea (OSA) in consideration of body mass index (BMI), biochemical tests and ultrasonographic liver data of 137 subjects. Patients with sleep apnea and AHI scores of < 5, 5 - 14, 15 - 29 and ≥30 are categorized as control, mild, moderate and severe, respectively.

Results:

One hundred and thirty-seven patients (76 women, 61 men) with a mean age of 55.75 ± 10.13 years who underwent polysomnography were included in the study. Of 118 patients diagnosed with OSA, 19 (16.1%) had mild OSA, 39 (33.1%) moderate OSA and 60 (50.8%) severe OSA. Nineteen cases formed the control group. Apnea/hypopnea index and oxygen desaturation index (ODI) values were significantly higher in moderate and severe non-alcoholic fatty liver disease (NAFLD) compared to the non-NAFLD group. Mean nocturnal SpO₂ values were significantly lower in mild NAFLD and severe NAFLD compared to the non-NAFLD group. Lowest O₂ saturation (LaSO₂) was found low in mild, moderate and severe NAFLD compared to the non-NAFLD group in a statistically significant manner.

Conclusions:

We assessed polysomnographic parameters of AHI, ODI, LaSO₂ and mean nocturnal SpO₂ levels, which are especially important in the association between NAFLD and OSAS. We think that it is necessary to be attentive regarding NAFLD development and progression in patients with OSA whose nocturnal hypoxia is severe.     

Twenty-four-hour ambulatory oxygen desaturation and electrocardiographic recording in obstructive sleep apnea syndrome

Background: Although nocturnal pulseoximetry is routinely performed in obstructive sleep apnea syndrome (OSAS), pulseoximetry over a 24-h period has not been studied. Hypothesis: The purpose of the study was to determine whether simultaneous 24-h oxygen desaturation and electrocardiographic (ECG) recording might be used to screen for daytime sleep sequelae in patients with OSAS. Methods: Simultaneous recording of arterial oxygen saturation (SpO2) and ECG was conducted over a 24-h period in 18 male patients with OSAS (mean age 51.3 years) who were diagnosed by standard polysomnography (PSG), and in 15 agematched healthy subjects (mean age 52.7 years) as controls to evaluate circadian variation of these parameters. The measures of heart rate variability (HRV) were calculated from 24-h ambulatory ECGs. Seventeen patients with OSAS showed excessive daytime sleepiness (EDS). We calculated the duration in which SpO₂ decreased to <90% (duration of SpO₂ > 90%). The number of apnea/hypopneas per hour (AHI) during sleep was investigated with Apnomonitors (Chest MI, Co., Tokyo) on the same day as the SpO₂ recordings. Results: Controls showed no episodes of oxygen desaturation. in patients with OSAS, driving (33.3% of patients with OSAS) was the most common activity in which SpO₂ decreased to <90%, followed by daytime napping (27.8%) and resting after meals (22.2%). The duration of SpO₂ < 90% over a 24-h period correlated significantly with the duration levels recorded during sleep (r = 0.99, p < 0.05) and in the afternoon (r = 0.62, p <0.05), and with the AHI (r = 0.55, p>0.05), but not with the duration of SpO²> 90% in the morning. The number of ventricular premature beats correlated significantly with the duration of SpO²>90% for a 24-h period, but not with measures of HRV. Ventricular tachycardia was found in two (11.1 %) and ST-T depression in three patients (16.6%) with underlying cardiac diseases. Conclusion: Our results suggest that daytime sleep attacks accompanied by oxygen desaturation in patients with moderate to severe OSAS may contribute to the occurrence of traffic or cardiovascular accidents. We conclude that 24-h ambulatory recordings of SpO² and ECG are useful for screening for daytime sleep sequelae associated with the potential risk of this pathology in OSAS during social activities.     

Sleep findings and predictors of sleep desaturation in adult cystic fibrosis patients

Purpose

Questions remain about the polysomnographic findings and the predictors for sleep desaturation in cystic fibrosis (CF) patients. Our study aimed to evaluate sleep parameters in a sample of adult CF patients comparing them with healthy controls and to determine the best predictors of sleep desaturation in CF patients with awake resting peripheral oxygen saturation (SpO₂) ??90%.

Methods

In a cross-sectional study, with data collected prospectively, 51 clinically stable adult CF patients (mean age 25.1?±?6.7?years) and 25 age-matched controls underwent an overnight polysomnography and answered sleep questionnaires. CF patients had their pulmonary function, 6-min walk test, and echocardiography assessed.

Results

CF patients and control subjects had similar sleep architecture. However, CF patients had impaired subjective sleep quality and a higher arousal index than controls. The apnea?Chypopnea index was similar in both groups, and only two CF patients (3.9%) fulfilled the criteria for obstructive sleep apnea syndrome. Sleep desaturation was more common in CF patients (29.4% vs 0%; p?2 was the single best variable associated with sleep desaturation in CF population (p?2 <94% had a sensitivity, specificity, positive and negative predictive value for sleep desaturation of, respectively, 93.3%, 100%, 100%, and 97.3%.

Conclusions

CF patients had a worse subjective sleep quality and small changes in sleep architecture. In nonhypoxic, adult CF patients, sleep desaturation is common, is not associated with obstructive sleep events, and can be accurately predicted by awake resting SpO₂ <94%.     

Hypoxemia in patients on chronic opiate therapy with and without sleep apnea

Objective  Animal models have shown a quantal slowing of respiratory pattern when exposed to opioid agonist, in a pattern similar to that observed in central sleep apnea. We postulated that opioid-induced hypoventilation is more likely to be associated with sleep apnea rather than hypoventilation alone. Since we did not have a direct measure of hypoventilation we used hypoxemia as an indirect measure reasoning that significant hypoventilation would not occur in the absence of hypoxemia. Methods  We conducted a retrospective analysis of 98 consecutive patients on chronic opioid medications who were referred for overnight polysomnography. All patients on chronic opioids seen in the chronic pain clinic were referred for a sleep study regardless of whether they had sleep symptoms or not. Sleep-related hypoxemia was defined as arterial oxyhemoglobin saturation of less than 90% for more than 5 min with a nadir of ≤85%, or greater than 30% of total sleep time at an oxyhemoglobin saturation of less than 90%. Results  Of the 98 patients, 36% (95% CI 26–46%) had obstructive sleep apnea, 24%, (95% CI 16–33%) had central sleep apnea, 21% (95% CI 14–31%) had combined obstructive and central sleep apnea, in 4% (95% CI 0–10%) sleep apnea was classified as indeterminate, and 15% (95% CI 9–24%) had no sleep apnea. Opioids were potentially responsible for hypoxemia during wakefulness in 10% of patients (95% CI 5–18%) and for hypoxemia during sleep not clearly associated with apneas/hypopneas in 8% of patients (95% CI 4–15%). Two patients (2%, 95% CI 0–7%) had sleep-related hypoxemia in the absence of sleep apnea or hypoxemia during wakefulness. Conclusions  Patients on chronic opiate therapy for chronic pain have an extremely high prevalence of sleep apnea and nocturnal hypoxemia. Hypoxemia can occur during quiet wakefulness in patients on chronic opioid medications with and without sleep apnea. In patients on chronic opioid therapy, isolated nocturnal hypoxemia without coexisting sleep apnea or daytime hypoxemia is very uncommon.     

Hyperinflation is Associated with Lower Sleep Efficiency in COPD with Co-existent Obstructive Sleep Apnea

ABSTRACT

Prior research has shown that individuals with obstructive lung disease are at risk for sleep fragmentation and poor sleep quality. We postulated that patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (known as overlap syndrome) who have more severe lung disease, as measured by lung hyperinflation (inspiratory capacity/total lung capacity), would have greater sleep disturbances independent of traditional measures of sleep apnea. We performed a retrospective chart review of consecutive patients evaluated and treated in an academic pulmonary clinic for overlap syndrome. Pulmonary function tests and polysomnogram data were collected. Thirty patients with overlap syndrome were included in the analysis. We found significant univariable associations between sleep efficiency and apnea/hypopnea index (β = ?0.285, p = 0.01) and between sleep efficiency and lung hyperinflation (β = 0.654, p = 0.03). Using multivariable linear regression, the relationship between sleep efficiency and lung hyperinflation remained significant (β = 1.13, p = 0.02) after adjusting for age, sex, body mass index, apnea/hypopnea index, FEV₁% predicted, oxygen saturation nadir, medications, and cardiac disease. We conclude that increased severity of hyperinflation is associated with worse sleep efficiency, independent of apnea and nocturnal hypoxemia. The mechanisms underlying this observation are uncertain. We speculate that therapies aimed at reducing lung hyperinflation may improve sleep quality in patients with overlap syndrome.     

Respiratory disturbance during sleep in COPD patients without daytime hypoxemia

Chronic obstructive pulmonary disease (COPD) is associated with significant morbidity and mortality. Its possible association with obstructive sleep apnea is a major cause of concern for clinicians. As the prevalence of both COPD and sleep apnea continues to rise, further investigation of this interaction is needed. In addition, COPD patients are at risk for hypoventilation during sleep due to the underlying respiratory dysfunction. In this study, 13 COPD subjects and 13 non-COPD control subjects were compared for the presence and severity of obstructive sleep apnea and nocturnal hypoventilation. All 26 subjects had presented to a sleep clinic and showed no signs of daytime hypoxemia. After matching for BMI and age, COPD subjects had a similar prevalence of sleep apnea with a lower degree of severity compared to the control subjects. However, less severe events, such as RERA, occurred at similar rates between the two groups. There was no significant difference between groups in the magnitude of oxyhemoglobin desaturation during sleep. Interestingly, severity and presence of nocturnal hypoxemia correlated with that of sleep apnea in the control group, but not in the COPD subjects. In conclusion, COPD without daytime hypoxemia was not a risk factor for sleep apnea or nocturnal hypoventilation in this study.     

Impact of Interface Type on Noninvasive Ventilation Efficacy in Patients With Neuromuscular Disease: A Randomized Cross-Over Trial

Background and objectiveAround 25% of patients with neuro-muscular diseases (NMD) are treated by home noninvasive ventilation (NIV) through an oronasal mask. However, there is growing evidence that nasal masks require lower NIV pressures and result in fewer residual obstructive events. We hypothesized that nasal masks would improve efficacy and reduce side effects compared to oronasal masks in this population.Methodsopen label, cross-over, randomized, study in 2 tertiary care hospitals. Patients with NMD treated by home NIV were randomized for one-week periods to nasal and oronasal interfaces respectively (cross-over). At the end of each period, nocturnal polygraphy (monitoring mouth opening) under NIV, synchronized with transcutaneous partial pressure in CO₂ (tcCO₂) was performed. Data were collected from the NIV built-in software and NIV side-effects were collected. Intention-to-treat and per protocol analyses were performed. The primary outcome was mean nocturnal SpO₂. The secondary outcomes were: percentage of sleep with SpO₂ < 90%, oxygen desaturation index (ODI), mean tcCO₂, mean duration of mouth opening during sleep, level of non-intentional leaks and side-effects.ResultsThirty patients with NMD were included. There were no between-group differences for either the primary or secondary outcomes. Post hoc comparisons showed that changing between interfaces reduced NIV efficacy: mean nocturnal SpO₂ (p = 0.04), ODI (p = 0.01), mean tcCO2 (p = 0.048), side-effects (p = 0.008).ConclusionNasal masks did not improve NIV efficacy or reduce side effects compared to oronasal masks in patients with NMD treated by home NIV. The efficacy of NIV is reduced during the transition to another interface, requiring close monitoring.Registration number: NCT03458507.     

Sleep disordered breathing does not predict acute severe pain episodes in children with sickle cell anemia

Conflicting evidence has suggested that low mean nocturnal hemoglobin oxygen saturation (SpO₂) predicts future hospital days for acute severe pain in children with sickle cell anemia (SCA). In an unselected multicenter prospective cohort study, we tested the hypothesis that either low mean nocturnal SpO₂ or high obstructive apnea‐hypopnea index (OAHI; the number of obstructive apneas and hypopneas with ≥ 3% desaturation or arousal per hour of sleep) or high oxygen desaturation index (ODI; number of ≥ 3% desaturation from baseline saturation per hour of sleep) is associated with increased incidence rates of pain. A total of 140 children with SCA with a median age of 10.8 years (interquartile range 7.2) were followed for a median of 4.9 years (interquartile range 1.8). Overnight polysomnography evaluations at baseline health exam were measured and adjudicated centrally. Multivariable models created in two steps were included. First, all plausible covariates were included in a screening model. Subsequently, covariates meeting level of statistical significance of P < .20 were included in the final model. Contrary to our hypothesis, higher (but not lower) mean nocturnal SpO₂ was associated with higher rates of pain episodes (Incidence rate ratio (IRR) 1.10, 95% CI [1.03‐1.18], P = .004). Higher log OAHI did not pass screening criteria. Higher log ODI was not significantly associated with higher rates of pain episodes (IRR 0.93, 95% CI [0.82‐1.06], P = .28). Neither low nocturnal SpO2, higher OAHI, nor higher ODI were associated with clinically relevant increased incidence rates of acute severe pain episodes.     

Sleep Disordered Breathing in Patients with Chronic Obstructive Pulmonary Disease

Sleep-related disordered breathing (SDB) and its influence on desaturation were examined in stable COPD patients with waking SpO₂ > 90%. With respiratory inductance plethysmography, thoracic-abdominal respiratory movements for all events with more than 4% desaturation were analyzed in 26 patients. Types of SDB were confirmed by full polysomnography. Irregular breathing induced desaturation, while stable respiration continued during some desaturation events. Three types of altered ventilation were observed: hypoventilation, paradoxical movement and periodic breathing. An unusual type of paradoxical movement, with normal airflow despite progressive desaturation, was observed in REM sleep. Patients were divided into desaturation (15 patients) and non-desaturation (11 patients) groups. Daytime arterial blood gas, lung function values, and 6-min walking distance did not differ. Awake, mode, maximum and minimum nocturnal SpO₂ were lower in the desaturation group. SDB-induced desaturation events in the desaturation group were more frequent (9.2 ± 3.5 vs. 1.8 ± 2.2 times), a greater SpO₂ decrease (11.4 ± 7.1% vs. 5.2 ± 2.1%) and longer duration (73.2 ± 34.8 vs. 18.8 ± 39.0 min). Patterns of SDB in the desaturation group were hypoventilation (74.4 ± 23.4%), paradoxical movement (10.2 ± 14.5%), periodic breathing (12.1 ± 18.3%) and unclassified (5.8 ± 11.2%). These results reveal that lower SpO₂ and SDB influence nocturnal desaturation in stable COPD patients.     

Nocturnal hypoxemia in children and adolescents with cystic fibrosis

OBJECTIVE:

To determine the prevalence of nocturnal hypoxemia and its association with pulmonary function, nutritional status, sleep macrostructure, and obstructive respiratory events during sleep in a population of clinically stable children and adolescents with cystic fibrosis (CF).

METHODS:

This was a cross-sectional study involving 67 children and adolescents with CF between 2 and 14 years of age. All of the participants underwent polysomnography, and SpO₂ was measured by pulse oximetry. We also evaluated the Shwachman-Kulczycki (S-K) scores, spirometry findings, and nutritional status of the patients.

RESULTS:

The study involved 67 patients. The mean age of the patients was 8 years. The S-K scores differed significantly between the patients with and without nocturnal hypoxemia, which was defined as an SpO₂ < 90% for more than 5% of the total sleep time (73.75 ± 6.29 vs. 86.38 ± 8.70; p < 0.01). Nocturnal hypoxemia correlated with the severity of lung disease, FEV₁ (r_s = −0.42; p = 0.01), FVC (r_s = −0.46; p = 0.01), microarousal index (r_s = 0.32; p = 0.01), and apnea-hypopnea index (r_s = 0.56; p = 0.01).

CONCLUSIONS:

In this sample of patients with CF and mild-to-moderate lung disease, nocturnal oxygenation correlated with the S-K score, spirometry variables, sleep macrostructure variables, and the apnea-hypopnea index.