Nocturnal blood pressure fluctuation and associated influential factors in severe obstructive sleep apnea patients with hypertension

Purpose

Obstructive sleep apnea syndrome (OSAS) can induce dramatic blood pressure (BP) fluctuations during sleep and it can be associated with hypertension. We investigated the properties and associated influential factors of BP fluctuation in severe OSAS with and without hypertension.

Methods

Two hundred one severe OSAS subjects were divided into hypertensive and normotensive groups. BP was continuously monitored via measurement of pulse transmit time (PTT). The value of apnea-related systolic BP elevation (ΔSBP) was used to reflect the amplitude of BP fluctuation, and the SBP index (the number of ΔSBP >?10 mmHg per hour of sleep time) was used to stand for the frequency of significant BP fluctuations.

Results

Compared with the normotensive group, △SBP and SBP index were higher in the hypertensive group (13.8?±?4.4 mmHg vs 10.9?±?3.1 mmHg; 44.8?±?21.3 events/h vs 26.8?±?15.8 events/h, all p?<?0.001). Multiple regression analysis showed that percentage of sleep time with oxygen saturation <?90% (TST90) and SBP index correlated more with mean level of awakeness and sleep SBP than with apnea-hypopnea index (AHI). Analysis of all apnea events demonstrated that △SBP and the frequency of BP fluctuations were more remarkable following hypoxia than following arousal; △SBP correlated more with oxygen desaturation degree (r?=?0.388, p?<?0.01) and minimal SpO₂ (r?=?0.392, p?<?0.01) than with apnea length and desaturation duration.

Conclusions

In severe OSAS, nocturnal and awake BP levels are associated more with the nocturnal hypoxic duration and BP fluctuation than with AHI. Nocturnal BP fluctuation can be induced by both hypoxia and arousal, and especially by hypoxia.

Trial registration

NCT02876471

     

A fatty meal aggravates apnea and increases sleep in patients with obstructive sleep apnea

Purpose

The purpose of this study was to investigate the role of a fatty meal before bedtime, on sleep characteristics and blood pressure in patients with obstructive sleep apnea (OSA).

Methods

Recently diagnosed, by full polysomnography (PSG), patients with OSA (n?=?19) were included. These underwent PSG for additional two consecutive nights. Two hours before the PSG examination, a ham and cheese sandwich of 360 kcal was served to all patients, at first night, while a fatty meal of 1,800 kcal was served before the second PSG examination. Comparisons were performed between the last two examinations in terms of PSG data and morning and night blood pressure measurements.

Results

After the fatty meal, a significant increase was observed in total sleep time (p?=?0.026) in the Apnea–Hypopnea Index (AHI) (p?=?0.015), as well as in the absolute number of obstructive and central apneas (p?=?0.032 and p?=?0.042, respectively) compared to the previous night. Conversely, distribution of sleep stages and indices of nocturnal hypoxia (average and minimum SpO₂ and sleep time with SpO₂?<?90 %) did not change significantly. Likewise, no significant change was observed in blood pressure measurements.

Conclusions

Fatty meal intake before sleep can increase AHI in OSA patients, although it does not affect sleep architecture or indices of hypoxia.     

The impact of obesity on cardiac dysfunction in patients with sleep-disordered breathing

Introduction

Obesity and heart failure are strongly associated with sleep-disordered breathing (SDB). However, the determinants of cardiac dysfunction in patients with SDB are not known.

Methods

We studied 90 patients suspected of having SDB (66 % women and 67 % black), age 50.4?±?13.4 years and body mass index (BMI) 38.6?±?9.8 kg/m². Apnea–hypopnea index (AHI) and nadir pulse oximetry (SpO₂) were determined by polysomnography recordings. Left atrial (LA) diameter and left ventricular posterior wall (LVPW) thickness were determined by echocardiography. Patients who had EF?<?50 %, estimated right ventricular systolic pressure >45 mmHg or valvular heart disease were excluded.

Results

Univariate analysis revealed a positive correlation between LA diameter and each of BMI, neck circumference (NC), and AHI (coefficients, 0.28, 0.34, and 0.36, respectively; p?<?0.05). Multivariable linear regression analysis revealed that BMI was the only independent predictor of LA enlargement (coefficient 0.02, p?<?0.05). LVPW thickness correlated with BMI, NC, and AHI (correlation coefficients were 0.43, 0.47, and 0.33, respectively; p?<?0.05). Multivariable linear regression analysis revealed a significant relationship between LVPW thickness and each of BMI and NC (coefficients 0.016 and 0.007, respectively; p?<?0.05) but not AHI. BMI and LVPW associated with nadir SpO₂ (r?=??0.60, p?<?0.01 and r?=??0.21, p?=?0.05; respectively), and BMI was a predictor of nadir SpO₂ during sleep (B?=??0.59; CI: ?0.84, ?0.33; p?=?0.01).

Conclusions

Obesity can predict cardiovascular morbidity and nocturnal hypoxemia independent of the severity of the SDB. Our findings suggest the independent contribution of excess body weight on cardiac dysfunction and hypoxia in SDB patients.     

Assessment of sleep quality by pulse wave amplitude and actigraphy in children with sleep-disordered breathing: evaluation at diagnosis and under non-invasive ventilation

Purpose

The aims of this study were to assess the interest of pulse wave amplitude (PWA) and actigraphy for characterizing sleep in children with sleep-disordered breathing and to evaluate PWA and actigraphy to assess the efficacy of non-invasive positive pressure ventilation (NPPV).

Methods

We performed a retrospective analysis of children with sleep-disordered breathing. Patients were classified to upper airway obstructive disease (UAO) group or non-obstructive disease (non-UAO) group. Pulse oximetry (SpO₂) and PWA were measured by photoplethysmography. Autonomic micro-arousals (AA) and AA related to SpO₂ desaturations above 4 % (AA + DS4%) were quantified. The fragmentation index, sleep efficiency, sleep duration, and sleep latency were measured with actigraphy. Transcutaneous carbon dioxide (PtcCO₂) was monitored. NPPV was started in case of severe OSA.

Results

AA + DS4% were more common in the UAO (n?=?15) than the non-UAO group (n?=?13) (p?<?0.001). All nocturnal gas exchange parameters were worse in the UAO group. Eight children required NPPV. AA + DS4%, maximal PtcCO₂, percent of time with PtcCO₂?>?50 mmHg, and percent of time with SpO₂?<?90 % decreased significantly after 1 month of NPPV.

Conclusions

The analysis of AA + DS4% is very informative for the grading of the severity of OSA and for the efficacy of NPPV in children with sleep-disordered breathing.     

Validity of sheet-type portable monitoring device for screening obstructive sleep apnea syndrome

Purpose

The SD-101 is a non-restrictive sheet-like medical device that measures sleep-disordered breathing using pressure sensors that can detect the gravitational alterations in the body that accompany respiratory movement. One report has described that the screening specificity of the SD-101 for mild to moderate obstructive sleep apnea syndrome (OSAS) is relatively low. The present study examines whether the accuracy of the SD-101 for OSAS screening is improved by simultaneously measuring percutaneous oxygen saturation (SpO₂).

Methods

Sixty consecutive individuals with suspected OSAS consented to undergo overnight polysomnography (PSG) together with simultaneous measurements of SD-101 and SpO₂ at our laboratory.

Results

The apnea–hypopnea index (AHI) determined from PSG and the respiratory disturbance index determined from SD-101 measurements significantly correlated (SD-101 alone: r?=?0.871, p?<?0.0001; SD-101 with SpO₂: r?=?0.965, p?<?0.0001). Bland–Altman plots showed a smaller dispersion for the SD-101 with SpO₂ than for the SD-101 alone. The SD-101 with SpO₂ detected an AHI of >15 on PSG with a sensitivity and specificity of 96.9 and 90.5 % compared with 87.5 and of 85.7 %, respectively, of the SD-101 alone.

Conclusions

Simultaneously measuring SpO₂ improved the accuracy of the SD-101 for OSAS screening. Furthermore, this modality appears to offer high sensitivity and specificity for detecting even moderately severe OSAS.     

Effect of transnasal insufflation on sleep disordered breathing in acute stroke: a preliminary study

Background and Purpose

Sleep disordered breathing (SDB) is frequent in acute stroke patients and is associated with early neurologic worsening and poor outcome. Although continuous positive airway pressure (CPAP) effectively treats SDB, compliance is low. The objective of the present study was to assess the tolerance and the efficacy of a continuous high-flow-rate air administered through an open nasal cannula (transnasal insufflation, TNI), a less-intrusive method, to treat SDB in acute stroke patients.

Methods

Ten patients (age, 56.8?±?10.7?years), with SDB ranging from moderate to severe (apnea?Chypopnea index, AHI, >15/h of sleep) and on a standard sleep study at a mean of 4.8?±?3.7?days after ischemic stroke (range, 1?C15?days), were selected. The night after, they underwent a second sleep study while receiving TNI (18?L/min).

Results

TNI was well tolerated by all patients. For the entire group, TNI decreased the AHI from 40.4?±?25.7 to 30.8?±?25.7/h (p?=?0.001) and the oxygen desaturation index >3% from 40.7?±?28.4 to 31?±?22.5/h (p?=?0.02). All participants except one showed a decrease in AHI. The percentage of slow-wave sleep significantly increased with TNI from 16.7?±?8.2% to 22.3?±?7.4% (p?=?0.01). There was also a trend toward a reduction in markers of sleep disruption (number of awakenings, arousal index).

Conclusions

TNI improves SDB indices, and possibly sleep parameters, in stroke patients. Although these changes are modest, our findings suggest that TNI is a viable treatment alternative to CPAP in patients with SDB in the acute phase of ischemic stroke.     

Hypotensive effects of positive airway pressure ventilation in heart failure patients with sleep-disordered breathing

Introduction

Obstructive sleep apnoea (OSA) as well as central sleep apnoea (CSA) are highly prevalent in heart failure (HF) patients. Positive airway pressure (PAP) therapy is usually intended to treat OSA and CSA. The aim of the present study was to investigate immediate hemodynamic effects of PAP therapy in these patients.

Materials and methods

In 61 consecutive HF patients (NYHA????II, EF????45%) with moderate to severe OSA or CSA (AHI????15/h) blood pressure (BP) and heart rate (HR) response to PAP therapy initiation was investigated during mask fitting with patients being awake and in supine position. While applying an endexspiratory pressure of 5.8?±?0.9?cm H₂O, there was a significant decrease in systolic (?8.9?±?12.1?mmHg, p?p?p?=?n.s.).

Results

At least a transient drop in mean arterial pressure ??70?mmHg was seen in 10% of these patients. Logistic regression analysis revealed a significant impact of baseline BP on potential BP drops: lower baseline BP was associated with BP drops.

Conclusion

PAP therapy may cause unexpected hypotension especially in patients with low baseline BP as seen in HF patients treated according to current guidelines. Whether these hypotensive effects sustain, cause any harm to the patients and/or is responsible for non-acceptance or non-adherence of PAP therapy needs to be determined.     

Validation of ApneaLink Ox™ for the diagnosis of obstructive sleep apnea

Objective

The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox? (ALOX) in patients with suspected obstructive sleep apnea (OSA).

Methods

All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed.

Results

Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m²). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a–RDI, ?3.6?±?10.1; AHI4-a–RDI, ?6.5?±?10.9, p?<?0.05). The autoscoring from ALOX device showed a better performance when it was set up to identify hypopneas with an oxygen desaturation criterion of ≥3 % than when it was configured with an oxygen desaturation criterion of ≥4 % (area under the receiver operator curves, 0.87 vs. 0.84). Also, the manual analysis was found to be better than the autoscoring set up with an oxygen desaturation of ≥3 % (0.923 vs. 0.87). The manual analysis showed a good interobserver agreement for the classification of patients with or without OSA (k?=?0.81).

Conclusion

The AHI obtained automatically from the ApneaLink Ox? using oxygen desaturation ≥3 % as a criterion of hypopnea had a good performance to diagnose OSA. The manual scoring from ApneaLink Ox? was better than the automatic scoring to discriminate patients with OSA.     

Effect of musculoskeletal pain on sleep architecture in patients with obstructive sleep apnea

Rationale

Obstructive sleep apnea and chronic musculoskeletal pain both affect sleep. Sleep architecture of patients suffering from both is largely unknown.

Objectives

This study seeks to define the sleep architecture of patients with chronic musculoskeletal pain and obstructive sleep apnea.

Methods

Patients with obstructive sleep apnea diagnosed by sleep study during the past 3 years were included. Patients with clinical documentation of chronic musculoskeletal pain constituted cases, while others were classified as controls.

Measurements

Demographics, clinical factors affecting sleep, medications affecting sleep, Epworth sleepiness scores, and polysomnographic parameters; total sleep time, sleep efficiency, sleep stages, rapid eye movement (REM) sleep onset, apnea–hypopnea index, arousal index, and periodic leg movements were recorded.

Results

There were 393 subjects: 200 cases (obstructive sleep apnea and chronic musculoskeletal pain) and 193 controls (obstructive sleep apnea alone). There was significant difference in total sleep time (274.5?±?62.5 vs. 302.2?±?60.1 min, p?=?0.0001), sleep efficiency (73.54?±?15.8 vs. 78.76?±?14.3 %, p?=?0.0003), and REM sleep onset (148.18?±?80.5 vs. 124.8?±?70.9 min, p?=?0.006). Subgroup analysis within the obstructive sleep apnea with chronic musculoskeletal pain group revealed that subjects had better total sleep time and sleep efficiency if they were on REM sleep affecting medications (suppressants and stimulants). Those on REM sleep suppressants slept 25.7 min longer and had 6.4 % more efficient sleep than those not on REM suppressants (p?=?0.0034 and p?=?0.0037).

Conclusion

Patients with obstructive sleep apnea and chronic musculoskeletal pain sleep not only significantly less but also with inferior sleep quality. Their REM sleep is also less in duration and its onset is delayed. Despite low TST and SE, these patients may not exhibit sleepiness.     

Genetics correlates with lung function and nocturnal ventilation in myotonic dystrophy

Background

Dystrophia myotonica (DM) is the most frequent adult-onset muscular dystrophy. Type 1 is caused by the cytosine–thymine–guanine (CTG) repeat expansion in the DM protein kinase gene. Respiratory muscle weakness and altered central ventilatory control lead to hypercapnia and lung volume restriction.

Purpose

This study aims to review the respiratory involvement in DM patients and study its relation with genetics.

Methods

Retrospective study of patients with DM referred for respiratory assessment was made. Noninvasive ventilation (NIV) was considered to daytime hypercapnia or symptoms of nocturnal hypoventilation.

Results

Forty-two consecutive patients (37.9?±?13.6 years) were evaluated. Mean CTG length was 642.8?±?439.2 repeats. In the first evaluation, mean forced vital capacity (FVC) was 74.4?±?20.2 %, maximal expiratory pressure (MEP) 35?±?16 %, maximal inspiratory pressure 52?±?23 %, peak cough flow (PCF) 327.3?±?97.7 L/min, arterial pressure of oxygen 79.7?±?11.3 mmHg, arterial pressure of carbon dioxide 45.5?±?6.2 mmHg, overnight minimal peripheral oxygen saturation (SpO₂) 79.6?±?11.6 %, and apnea–hypopnea index 13.9?±?9.9. CTG length was found to be related with MEP (r?=??0.67; p?=?0.001) and SpO₂ (r?=??0.37; p?=?0.039). NIV was started in 25 patients. Ventilated patients had lower FVC (2.19 to 3.21 L; p?<?0.001) and PCF (285.3 to 388.5 L/min; p?=?0.003) and more CTG repeats (826.6 to 388.5 repeats; p?=?0.02). NIV compliance was poor in seven patients (28 %) and related with hypercapnia (r?=?0.87; p?=?0.002) and inspiratory positive airway pressure setting (r?=?0.65; p?=?0.009). Ventilation improved symptoms and nocturnal hypoventilation. Comparing the first and last evaluations, only PCF was significantly lower (275.0 to 310.8 L/min; p?=?0.019).

Conclusions

Ventilatory insufficiency is very common in patients with DM and CTG length may be useful to predict it. Prolonged NIV improves symptoms, nocturnal hypoventilation and maintains daily blood gases. Routine evaluation of PCF should not be forgotten and assisted coughing training provided.     

Dynamic Hyperinflation Correlates with Exertional Oxygen Desaturation in Patients with Chronic Obstructive Pulmonary Disease

Background

Dynamic hyperinflation (DH) causes exercise limitation and exertional dyspnea in patients with chronic obstructive pulmonary disease (COPD). Exertional desaturation (ED) also occurs commonly in COPD but neither routine physiologic parameters nor imaging predict ED accurately. In this study we evaluated the relationship between DH and ED during 6-min walk testing (6MWT).

Methods

We measured ED and DH in patients with stable COPD. SpO₂ was measured by continuous pulse oximetry during 6MWT. ED was defined as a decline in SpO₂ (ΔSpO₂) ≥4 %. DH was determined by measuring inspiratory capacity (IC) before and after the 6MWT using a handheld spirometer. DH was defined as ΔIC >0.0 L. We correlated DH and ED with clinical and pulmonary physiologic variables by regression analysis, χ ², and receiver operator curve (ROC) analysis.

Results

Thirty males [age = 65 ± 9.4 years, FEV₁ % predicted = 48 ± 14 %, and DLCO % predicted = 50 ± 21 % (mean ± SD)] were studied. ΔSpO₂ correlated with ΔIC (r = 0.49, p = 0.005) and age (r = 0.39, p = 0.03) by univariate analysis; however, only ΔIC correlated on multivariate regression analysis (p = 0.01). ΔSpO₂ did not correlate with FEV₁, FVC, FEF_25–75, RV, DLCO % predicted, BMI, smoking, BORG score, or distance covered in 6MWT. DH strongly correlated with ED (p = 0.001). On ROC analysis, DH had an area under the curve of 0.92 for the presence of ED (sensitivity = 90 %; specificity = 77 %, p < 0.001).

Conclusion

Routine pulmonary function test results and clinical variables did not correlate with ED in patients with stable COPD. Dynamic hyperinflation strongly correlates with exertional desaturation and could be a reason for this desaturation.     

Multi-modal ECG Holter system for sleep-disordered breathing screening

Background

The high prevalence of sleep disordered breathing (SDB) among heart diseases patients becomes increasingly recognized. A reliable exploring tool of SDB well adapted to cardiologists practice would be very useful for the management of these patients.

Methods

We assessed a novel multi-modal electrocardiogram (ECG) Holter which incorporated both thoracic impedance and pulse oximetry signals. We compared in a home setting, a standard condition for Holter recordings, results from the novel device to a classical ambulatory polygraph in subjects with suspected SDB. The analysis of cardiac arrhythmias in relationship with SDB is also presented. A total of 118 patients clinically suspected of having SDB were evaluated (mean age 57?±?14?years, mean body mass index [BMI] 32?±?6?kg/m²). The new device allows calculating a new index called thoracic impedance (TI) disturbance index (TIDI+) evaluated from TI and SpO₂ signals recorded from a Holter monitor.

Results

In the population under study, 93% had more than 70% of usable TI signal and 95% had more than 90% for SpO₂ during sleep time recording. Screening performance results based on automatic analysis is accurate: TIDI?+?demonstrates a high level of sensitivity (96.8%), specificity (72.3%) as well as positive (82.4%) and negative (94.4%) predictive value for the detection of SDB. Moreover, detection of SDB periods permits us to observe a possible respiratory association of several nocturnal arrhythmias.

Conclusions

The multi-modal Holter should be considered as a valuable evaluating tool for SDB screening and as a case selection technique for facilitating access to a full polysomnography for severe cases. Moreover, it offers a unique opportunity to study arrhythmia consequences with both respiratory and hypoxia disturbances.     

Influence of CPAP treatment on airway and systemic inflammation in OSAS patients

Aim

Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent respiratory disorders in the upper airways during sleep. Although continuous positive airway pressure (CPAP) has been accepted to be the most effective treatment for OSAS, its role on inflammation remains debatable. In this study, our aim was to examine the influence of 3 months of CPAP treatment on tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), 8-isoprostane, and peroxynitrite levels in exhaled breathing condensates (EBC) and serum.

Methods

Thirty-five patients who were newly diagnosed as moderate or severe OSAS with full night polysomnography and used CPAP therapy regularly for 3 months were included in the study. Polysomnography, spirometric tests, fasting blood samples, and EBC were ascertained on entry into the study and after 3 months of treatment. All patients were assessed monthly for treatment adherence and side effects.

Results

We found that all polysomnographic parameters were normalized after CPAP therapy in the control polysomnogram. Also, all markers in EBC and nitrotyrosine and 8-isoprostane levels in serum were decreased significantly with CPAP treatment. Sedimentation rate, C-reactive protein, IL-6, and TNF-α remained unchanged in serum after treatment. We found that baseline nitrotyrosine levels were significantly correlated with apnea–hypopnea index, oxygen desaturation index, and percent time in SpO₂?<?90 % (p?<?0.01).

Conclusions

CPAP therapy has primarily a relevant impact on airways, and nitrotyrosine levels correlated well with severity of OSAS. This treatment decreases both inflammation and oxidative stress levels in airways in OSAS patients. Also, this treatment helps to decrease systemic oxidative stress levels in serum.     

Determination of new prediction formula for nasal continuous positive airway pressure in Turkish patients with obstructive sleep apnea syndrome

Background

Race/ethnicity may play an important role in determining body size, severity of obstructive sleep apnea syndrome (OSAS), and effective continuous positive airway pressure (CPAP) (Peff). Turkey is composed of different ethnic groups. Therefore, the aims of this study were to determine new prediction formula for CPAP (Ppred) in Turkish OSAS patients, validate performance of this formula, and compare with Caucasian and Asian formulas.

Methods

Peff of 250 newly diagnosed moderate-to-severe OSAS patients were calculated by in-laboratory manual titration. Correlation and multiple linear regression analysis were used to model effects of ten anthropometric and polysomnographic variables such as neck circumference (NC) and oxygen desaturation index (ODI) on Peff. New formula was validated in different 130 OSAS patients and compared with previous formulas.

Results

The final prediction formula was $ {\text{Ppred}} = \left( {0.{148} \times {\text{NC}}} \right) + \left( {0.0{38} \times {\text{ODI}}} \right) $ . When Peff of control group was assessed, it was observed that mean Peff was 8.39?±?2.00?cmH₂O and Ppred was 8.23?±?1.22?cmH₂O. Ppred was within ±3?cmH₂O of Peff in 96.2% patients. Besides, Peff was significantly correlated with new formula, and prediction formulas developed for Caucasian and Asian populations (r?=?0.651, p?<?0.001, r?=?0.648, p?<?0.001, and r?=?0.622, p?<?0.001, respectively).

Conclusions

It is shown that level of CPAP can be successfully predicted from our prediction formula, using NC and ODI and validated in Turkish OSAS patients. New equation correlates with other formulas developed for Caucasian and Asian populations. Our simple formula including ODI, marker of intermittent hypoxia, may be used easily in different populations.     

The effect of non-benzodiazepine hypnotics on sleep quality and severity in patients with OSA: a meta-analysis

Purpose

Although there is a high co-occurrence of insomnia and obstructive sleep apnea (OSA), the administration of sedative hypnotics in patients with OSA is still inconsistent. The aim is to study the effect of non-benzodiazepine hypnotics (non-BZDs) on sleep quality and severity in patients with OSA.

Methods

We conducted a systemic search for controlled clinical trials in multiple databases and pooled analysis of the impact of non-BZDs on objective sleep quality and the severity of OSA, including the apnea-hypopnea index (AHI) and mean and nadir arterial oxygen saturation (SaO₂) in patients with OSA. Sensitivity analysis was carried out to explore the robustness of results.

Results

Eight relevant placebo-controlled clinical trials involving 448 patients were included. Objective sleep quality, including sleep latency, sleep efficiency, and wake time after sleep onset, was significantly improved in patients taking non-BZDs compared with those taking placebo (p?2 in OSA patients (p?>?0.05).

Conclusions

The administration of non-BZDs at the commonly recommended dose has been shown to improve objective sleep quality in OSA patients without worsening sleep apnea. It suggests that OSA patients with a complaint of insomnia symptoms may benefit from taking non-BZDs.     

Risk factors for post-operative complications in Chinese children with tonsillectomy and adenoidectomy for obstructive sleep apnea syndrome

Purpose

Tonsillectomy and adenoidectomy (T&;A) is commonly performed in children with obstructive apnea syndrome (OSAS). It was our hospital practice to observe all patients post T&;A in the pediatric intensive care unit. We aim to describe the post-operative complications after tonsillectomy and adenoidectomy in children with OSAS and to identify risk factors for these complications.

Method

Medical records of patients from 1 to 16?years old with OSAS and T&;A done in this department were retrieved for analysis from April 1999 to July 2006. Information of the individual patients including the demographic data, polysomnography data, and presence of post-operative complications were recorded and analyzed.

Results

A total of 86 patient records were analyzed (M/F?=?69:17). The mean BMI z score was 1.13?±?1.53, and 36% of patients were classified as obese with z?>?1.96. The median apnea?Chypopnea index (AHI) before T&;A was 9.8 episodes/h. Only six patients had post-operative desaturation. No bleeding complications were reported in our cohort. It was found that patients with desaturation after T&;A had significantly higher mean BMI z score than children without desaturation (p?=?0.014). There was otherwise no significant difference between the age, sex, AHI score, and the history of allergic rhinitis or asthma between the two groups.

Conclusion

Our results showed that most children with OSAS underwent T&;A without complications. The respiratory complication rate was 7%, and desaturation was the most common post-operative complication. Children with higher BMI z score were more likely to have desaturation after T&;A (p?=?0.014). Hence, careful monitoring with pulse oximeter after T&;A should be offered to those who are obese.     

Continuous positive airway pressure intolerance associated with elevated nasal resistance is possible mechanism of complex sleep apnea syndrome

Purpose

Complex sleep apnea syndrome (CompSAS) is diagnosed after an elimination of obstructive events with continuous positive airway pressure (CPAP), when a central apnea index ??5/h or Cheyne?CStokes respiration pattern emerges in patients with obstructive sleep apnea syndrome (OSAS). However, the pathophysiology of CompSAS remains controversial.

Methods

Of the 281 patients with suspected OSAS, all of whom underwent polysomnography conducted at Nagoya University Hospital, we enrolled 52 patients with apnea?Chypopnea index ??15/h (age 51.4?±?13.3?years). The polysomnographic findings, left ventricular ejection fraction (LVEF), and nasal resistance were compared between the CompSAS patients and OSAS patients.

Results

Forty-three patients were diagnosed with OSAS and nine patients with central sleep apnea syndrome by natural sleep PSG. Furthermore, 43 OSAS patients were classified into the OSAS patients (OSAS group, n?=?38) and the CompSAS patients (CompSAS group, n?=?5) by the night on CPAP PSG. The nasal resistance was significantly higher in CompSAS group than in OSAS group (0.30?±?0.10 vs. 0.19?±?0.07?Pa/cm³/s, P?=?0.004). The arousal index, percentage of stage 1 sleep, and oxygen desaturation index were significantly decreased, and the percentage of stage REM sleep was significantly increased in the OSAS group with the initial CPAP treatment, but not in the CompSAS group. In addition, the patients with CompSAS showed normal LVEF.

Conclusion

CPAP intolerance secondary to an elevated nasal resistance might relate to frequent arousals, which could presumably contribute to an increase in central sleep apnea. Further evaluation in a large study is needed to clarify the mechanism of CompSAS.     

Ambulatory screening for obstructive sleep apnea in patients with resistant arterial hypertension

Objective

Obstructive sleep apnea (OSA) is one of the most common causes of secondary arterial hypertension. It is important to rule out OSA as a cause of resistant hypertension. The ApneaLink device is a simple and cost-efficient outpatient examination, but its usefulness in screening OSA in resistant hypertension has not yet been evaluated.

Methods

A total of 69 patients with resistant arterial hypertension were enrolled. Patients underwent a physical examination, including the use of ApneaLink, followed by respiratory polygraphy. The presence of OSA was assessed by the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), mean nocturnal desaturation (SpO₂), and percentage of sleep time with SpO₂ less than 90%.

Results

There was no significant difference between the values of AHI found during the use of ApneaLink and respiratory polygraphy (mean 30.4 ± 21.7 vs. 37.2 ± 20.9, P = 0.07). ApneaLink had 77.3% sensitivity and 100% specificity to diagnose OSA with the area under the ROC curve 0.866 (P < 0.001). We also found no significant difference in mean SpO₂ (91.3 ± 2.5 vs. 90.9 ± 3.3%, P = 0.22). The ODI evaluated via ApneaLink was significantly lower than by the polygraphy (31.1 ± 18.3 vs. 43.9 ± 24.8, P < 0.001), while the measured percentage of sleep time with SpO₂ less than 90% was higher (31.8 ± 23.7 vs. 23.3 ± 24.4, P = 0.001). The severity of OSA was correctly determined by ApneaLink in 50.7% of patients, underestimated in 23.2% and overestimated in 26.1%.

Conclusions

The use of ApneaLink is a suitable method for screening the presence of OSA in patients with resistant hypertension, but to accurately assess the severity of OSA, respiratory polygraphy or polysomnography is required.

     

Energy expenditure in obstructive sleep apnea: validation of a multiple physiological sensor for determination of sleep and wake

Purpose

Obstructive sleep apnea (OSA) may be associated with increased energy expenditure (EE) during sleep. As actigraphy is inaccurate at estimating EE from body movement counts alone, we aimed to compare a multiple physiological sensor with polysomnography for determination of sleep and wake, and to test the hypothesis that OSA is associated with increased EE during sleep.

Methods

We studied 50 adults referred for routine overnight polysomnography. In addition to polysomnography, the SenseWear Pro3 Armband^TM (Bodymedia Inc.) was placed on the upper right arm. Epoch-by-epoch agreement rate between the measures of sleep versus wake was calculated. Linear regression analyses were performed for EE against apnea–hypopnea index (AHI), 3% oxygen desaturation index (ODI), body mass index (BMI), waist–hip ratio (WHR), gender, age, and average heart rate during sleep.

Results

The epoch-by-epoch agreement rate was high (79.9?±?1.6%) and the ability of the SenseWear to estimate sleep was very good (sensitivity, 88.7?±?1.5%). However, it was less accurate in determining wake (specificity 49.9?±?3.6%). Sleep EE was associated with AHI, 3% ODI, BMI, WHR, and male gender (p?<?0.001 for all). Stepwise multiple linear regression however revealed that BMI, male gender, age, and average heart rate during sleep were independent predictors of EE (Model R ²?=?0.78).

Conclusions

The SenseWear armband provides a reasonable estimation of sleep but a poor estimation of wake. Furthermore, in a selected population of OSA patients, increasing OSA severity is associated with increased EE during sleep, although primarily through an association with increased BMI. However, as our data are not adjusted for fat-free mass and the SenseWear has yet to be validated for EE in OSA patients, these data should be interpreted with caution.