Reverse atrial electrical remodelling induced by continuous positive airway pressure in patients with severe obstructive sleep apnoea

Background

Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and mortality, including atrial arrhythmias. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; its impact on atrial electrical remodelling has not been fully investigated. Signal-averaged p-wave (SAPW) duration is an accepted marker for atrial electrical remodelling.

Objective

The objective of this study is to determine whether CPAP induces reverse atrial electrical remodelling in patients with severe OSA.

Methods

Consecutive patients attending the Sleep Disorder Clinic at Kingston General Hospital underwent full polysomnography. OSA-negative controls and severe OSA were defined as apnoea–hypopnea index (AHI)?<?5 events/hour and AHI?≥?30 events/hour, respectively. SAPW duration was determined at baseline and after 4–6 weeks of CPAP in severe OSA patients or without intervention controls.

Results

Nineteen severe OSA patients and 10 controls were included in the analysis. Mean AHI and minimum oxygen saturation were 41.4?±?10.1 events/hour and 80.5?±?6.5 % in severe OSA patients and 2.8?±?1.2 events/hour and 91.4?±?2.1 % in controls. At baseline, severe OSA patients had a greater SAPW duration than controls (131.9?±?10.4 vs 122.8?±?10.5 ms; p?=?0.02). After CPAP, there was a significant reduction of SAPW duration in severe OSA patients (131.9?±?10.4 to 126.2?±?8.8 ms; p?<?0.001), while SAPW duration did not change after 4–6 weeks in controls.

Conclusion

CPAP induced reverse atrial electrical remodelling in patients with severe OSA as represented by a significant reduction in SAPW duration.     

CPAP therapy prevents increase in blood pressure after upper airway surgery for obstructive sleep apnoea

Objective

The aim of this study was to investigate the efficacy of continuous positive airway pressure (CPAP) therapy following uvulopalatopharyngoplasty (UPPP) to prevent blood pressure (BP) elevation during sleep.

Methods

Sixteen normotensive patients with OSA were subjected to UPPP with or without septoplasty. These patients were instrumented for 24 h of ambulatory BP recording, polysomnography, nocturnal urinary catecholamine and pain evaluation using a visual analogue scale in the day prior to surgery (D?1), following the surgery (D+1) and 30 days later (D+30). For the D+1, the patients were divided into two groups: the without CPAP therapy group and the with CPAP therapy group.

Results

The apnoea–hypopnoea index (AHI) significantly increased in the patients without CPAP therapy compared with the D?1 (74?±?23 vs. 35?±?6 times/h, p?<?0.05), and in the CPAP group, there was a significant reduction in the average AHI value to 14?±?6 times/h, p?<?0.01. During D+1, we observed an increase in the nocturnal systolic BP (10 %), diastolic BP (12 %) and heart rate (14 %) in the group without CPAP. These metrics were re-established in the CPAP group to values that were similar to those that were observed on the D?1. The absence of nocturnal dipping in the group without CPAP was followed by a significant increase in nocturnal norepinephrine (42?±?12 μg/l/12 h) and epinephrine (8?±?2 μg/l/12 h) levels compared with the D?1 (norepinephrine 17?±?3; epinephrine 2?±?0.3 μg/l/12 h, p?<?0.001). In the patients who used the CPAP treatment, the nocturnal catecholamine levels were similar to D?1. The effectiveness of intravenous analgesic therapy was verified by a significant decrease in the pain scores in patients both with and without CPAP therapy.

Conclusion

These data confirm an increase in the AHI on the night following UPPP with or without septoplasty. This increase promotes an absence of nocturnal dipping and a significant increase in urinary catecholamine levels. CPAP therapy was effective to prevent the transitory increase in BP.     

CPAP therapy in patients with idiopathic pulmonary fibrosis and obstructive sleep apnea: does it offer a better quality of life and sleep?

Background

The recent literature shows an increased incidence of obstructive sleep apnea (OSA) in patients with idiopathic pulmonary fibrosis (IPF). On the other hand, there are no published studies related to continuous positive airway pressure (CPAP) treatment in this patient group. Our aim was to assess the effect of CPAP on sleep and overall life quality parameters in IPF patients with OSA and to recognize and overcome possible difficulties in CPAP initiation and acceptance by these patients.

Methods

Twelve patients (ten males and two females, age 67.1?±?7.2 years) with newly diagnosed IPF and moderate to severe OSA, confirmed by overnight attended polysomnography, were included. Therapy with CPAP was initiated after a formal in-lab CPAP titration study. The patients completed the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), the Functional Outcomes in Sleep Questionnaire (FOSQ), the Fatigue Severity Scale (FSS), the SF-36 quality of life questionnaire, and the Beck Depression Inventory (BDI) at CPAP initiation and after 1, 3, and 6 months of effective CPAP therapy.

Results

A statistically significant improvement was observed in the FOSQ at 1, 3, and 6 months after CPAP initiation (baseline 12.9?±?2.9 vs. 14.7?±?2.6 vs. 15.8?±?2.1 vs. 16.9?±?1.9, respectively, p?=?0.02). Improvement, although not statistically significant, was noted in ESS score (9.2?±?5.6 vs. 7.6?±?4.9 vs. 7.5?±?5.3 vs. 7.7?±?5.2, p?=?0.84), PSQI (10.7?±?4.4 vs. 10.1?±?4.3 vs. 9.4?±?4.7 vs. 8.6?±?5.2, p?=?0.66), FSS (39.5?±?10.2 vs. 34.8?±?8.5 vs. 33.6?±?10.7 vs. 33.4?±?10.9, p?=?0.44), SF-36 (63.2?±?13.9 vs. 68.9?±?13.5 vs. 72.1?±?12.9 vs. 74.4?±?11.3, p?=?0.27), and BDI (12.9?±?5.5 vs. 10.7?±?4.3 vs. 9.4?±?4.8 vs. 9.6?±?4.5, p?=?0.40). Two patients had difficulty complying with CPAP for a variety of reasons (nocturnal cough, claustrophobia, insomnia) and stopped CPAP use after the first month, despite intense follow-up by the CPAP clinic staff. Heated humidification was added for all patients in order to improve the common complaint of disabling nocturnal cough.

Conclusion

Effective CPAP treatment in IPF patients with OSA results in a significant improvement in daily living activities based on the FOSQ, namely an OSA-specific follow-up instrument. Improvement was also noted in other questionnaires assessing quality of life, though not to a statistically significant degree, probably because of the multifactorial influences of IPF on physical and mental health. The probability of poor CPAP compliance was high and could only be eliminated with intense follow-up by the CPAP clinic staff.     

An electrocardiogram-based analysis evaluating sleep quality in patients with obstructive sleep apnea

Objective

The study compares polysomnography (PSG) and cardiopulmonary coupling (CPC) sleep quality variables in patients with (1) obstructive sleep apnea (OSA) and (2) successful and unsuccessful continuous positive airway pressure (CPAP) response.

Patients/methods

PSGs from 50 subjects (32 F/18 M; mean age 48.4?±?12.29 years; BMI 34.28?±?9.33) were evaluated. OSA patients were grouped by no (n?=?16), mild (n?=?13), and moderate to severe (n?=?20) OSA (apnea–hypopnea index (AHI)?≤?5, >5–15, >15 events/h, respectively). Outcome sleep quality variables were sleep stages in non-rapid eye movement, rapid eye movement sleep, and high (HFC), low (LFC), very low-frequency coupling (VLFC), and elevated LFC broad band (e-LFC_BB). An AHI?≤?5 events/h and HFC?≥?50 % indicated a successful CPAP response. CPC analysis extracts heart rate variability and QRS amplitude change that corresponds to respiration. CPC-generated spectrograms represent sleep dynamics from calculated coherence product and cross-power of both time series datasets.

Results

T tests differentiated no and moderate to severe OSA groups by REM % (p?=?0.003), HFC (p?=?0.007), VLFC (p?=?0.007), and LFC/HFC ratio (p?=?0.038) variables. The successful CPAP therapy group (n?=?16) had more HFC (p?=?0.003), less LFC (p?=?0.003), and e-LFC_BB (p?=?0.029) compared to the unsuccessful CPAP therapy group (n?=?8). PSG sleep quality measures, except the higher arousal index (p?=?0.038) in the unsuccessful CPAP group, did not differ between the successful and unsuccessful CPAP groups. HFC?≥?50 % showed high sensitivity (77.8 %) and specificity (88.9 %) in identifying successful CPAP therapy.

Conclusions

PSG and CPC measures differentiated no from moderate to severe OSA groups and HFC?≥?50 % discriminated successful from unsuccessful CPAP therapy. The HFC?≥?50 % cutoff showed clinical value in identifying sleep quality disturbance among CPAP users.     

Stage-matched intervention for adherence to CPAP in patients with obstructive sleep apnea: a randomized controlled trial

Purpose

The objective of the study was to evaluate the effectiveness of stage-matched intervention on adherence to continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome.

Methods

One hundred and ten Chinese patients with newly diagnosed obstructive sleep apnea syndrome were enrolled in this study. They were randomly assigned into stage-matched care (SMC) and standard care (SC) groups (55 patients in each group). Patients in the SMC group received stage-matched intervention at different stages of behavior changes, and the SC group received only routine care. The intervention was based on the health action process approach theory and included risk perception, outcome expectancy, and self-efficacy. Questionnaires included the Self-Efficacy Measure for Sleep Apnea, the Epworth Sleepiness Scale (ESS), and the Pittsburgh Sleep Quality Index (PSQI). Data were collected at baseline and 1 and 3 months after home CPAP treatment, and hours of CPAP usage was also recorded at 1 and 3 months of follow-up.

Results

At 1 month, CPAP usage was 5.59?±?0.56 h/night (mean ± SD) vs 5.28?±?0.67 h/night in the SMC and SC groups, respectively (p?=?0.016). At 3 months, CPAP usage was 5.65?±?0.50 vs 5.26?±?0.82 h/night in the SMC and SC groups, respectively (p?=?0.006). Repeated ANOVA analysis demonstrated that risk perception, outcome expectancy, and self-efficacy in the SMC group were significantly higher than those of the SC group (p?<?0.05). Moreover, the time × group interaction was significant for outcome expectancy and self-efficacy, indicating that the groups differed significantly in changes in outcome expectancy and self-efficacy over the three time points. There was a significant difference between the SMC and SC groups in terms of improvement in ESS (p?<?0.001) and PSQI (p?=?0.013) after 3 months of CPAP treatment.

Conclusions

Stage-matched intervention could not only facilitate intention formation and enhance treatment self-efficacy but significantly improve CPAP adherence in OSA patients for the 3-month treatment.     

Impact of continuous positive airway pressure on C-reactive protein in patients with obstructive sleep apnea: a meta-analysis

Purpose

C-reactive protein (CRP) is associated with the development of obstructive sleep apnea (OSA) and cardiovascular diseases. Continuous positive airway pressure (CPAP) is an effective treatment for OSA, but the impact of CPAP therapy on CRP levels in patients with OSA remains unclear. To obtain this information, we performed a meta-analysis to determine whether effective CPAP therapy could reduce serum CRP levels.

Methods

A comprehensive literature search was performed to identify studies that examined the impact of CPAP on serum CRP levels in OSA patients who were treated with CPAP for at least 4 weeks. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy.

Results

Fourteen self-control design studies involving 1199 patients with OSA met the inclusion criteria. Meta-analysis indicated that the overall SMD for the CRP levels was 0.64 units (95 % confidence interval (CI) 0.40 to 0.88) before and after CPAP therapy; test for overall effect z?=?5.27 (P?=?0.000). Subgroup analysis showed that evolution of CRP decreased non-significantly in less than 3 months (SMD, 0.26, 95 % CI ?0.08 to 0.60, P?=?0.138), significantly decreased after 3 months (SMD, 0.68, 95 % CI 0.34 to 1.02, P?=?0.000), and further declined after 6 months (SMD, 0.74, 95 % CI 0.43 to 1.05, P?=?0.000).

Conclusions

The systemic inflammation, as measured by CRP, was present and significantly reduced by effective CPAP therapy in patients with OSA. The use of CRP levels may be clinically recognized as a valuable predictor for OSA treatment monitoring.     

Assessment of the impact on compliance of a new CPAP system in obstructive sleep apnea

Background

Despite the efficacy of continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea (OSA), compliance with therapy remains suboptimal. The aim of this study was to determine whether the use of S9^TM increased compliance in established CPAP users.

Methods

Subjects with OSA (50) were recruited into the study. When subjects entered the study, 28 days of respective compliance data were downloaded from the patient's usual CPAP device. Subjects trialled the S9 CPAP for 28 days. Subjects then resumed use of their usual CPAP for 28 days. Compliance data from the patient's usual CPAP pre- and post-trialling S9 were compared with data from the S9 CPAP.

Results

Patients were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 based on average daily usage. CPAP pre-S9?=?6.58?±?1.95 (mean hours?±?SD), S9?=?7.08?±?1.18 h and CPAP post-S9?=?6.71?±?1.72 h. The difference between CPAP pre-S9 and S9 was 0.5 h (p?=?0.003). The difference between S9 and CPAP post-S9 was 0.35 h (p?=?0.01). There was no significant difference between CPAP pre-S9 and CPAP post-S9 (p?=?0.34). Patients also completed questionnaires comparing the S9 system to their usual device. Subjective feedback showed a strong preference for the S9.

Conclusions

Participants were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 use.     

Acute sleep deprivation is associated with increased arterial stiffness in healthy young adults

Background

Arterial stiffness and its hemodynamic consequences are known to be associated with increased cardiovascular morbidity and mortality. Pulse wave velocity (PWV) and augmentation index (AIx) are noninvasive indicators of the arterial stiffness and wave reflection. Sleep deprivation (SD) is known to be associated with increased incidence of adverse cardiovascular events. The aim of this study was to investigate whether there is an association between acute SD and arterial stiffness parameters in healthy adults, which has not been studied previously.

Methods

The study population consisted of 42 healthy volunteers (18 males, mean age 30.0?±?4.5 years). Measurements of arterial stiffness were carried out by using a Mobil-O-Graph arteriograph system. Arterial stiffness measurements were obtained both after a night with regular sleep (RS) and after a night with SD.

Results

Mean sleep time was significantly lower after the night of SD when compared after RS (0.73?±?1.39 versus 7.33?±?0.52 h, p?<?0.001). Peripheral systolic blood pressure, peripheral pulse pressure, and cardiac output were significantly higher after SD when compared after RS (p?=?0.032, 0.007, and 0.003, respectively). PWV was significantly higher (5.33?±?0.46 versus 5.15?±?0.26 m/s, p?=?0.001), and AIx was significantly lower (20.5?±?11.9 versus 26.0?±?8.4 %, p?=?0.008) after the night of SD when compared after the RS. While PWV was significantly higher (p?=?0.008), and AIx was significantly lower (p?=?0.039) in male subjects, only PWV was significantly higher (p?=?0.009) in female subjects. Sleep time correlated with AIx (p?=?0.034; r?=?0.233) and inversely correlated with PWV (p?=?0.044; r?=??0.222).

Conclusion

In the present study, we demonstrated that even one night of SD is associated with increased arterial stiffness in healthy adults. The present findings suggest that adverse effects of SD on cardiovascular system might be at least in part due to increased arterial stiffness which needs to be tested with large-scale studies and in the chronic SD setting.     

The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers

Purpose

Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain.

Methods

FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15 cm H₂O, applied in a random order. Transcutaneous carbon dioxide (PtcCO₂), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF.

Results

Data were obtained from 23 healthy volunteers (mean?±?SD; 12 male, age 25.1?±?2.6 years, body mass index 21.8?±?2.0 kg/m²). The mean experimental and theoretical CBF decrease under CPAP was 12.5 % (p?<?0.001) and 11.9 % (p?<?0.001), respectively. The difference between experimental and theoretical CBF reduction was not statistically significant (3.84?±?79 ml/min, p?=?0.40). There was a significant reduction in PtcCO₂ with CPAP (p?=?<0.001) and a significant increase in mean BP (p?=?0.0017). No significant change was observed in SaO₂ (p?=?0.21) and HR (p?=?0.62).

Conclusion

Duplex Doppler ultrasound measurements of arterial diameter and FV allow for a noninvasive bedside estimation of CBF. CPAP at 15 cm H₂O significantly decreased CBF in healthy awake volunteers. This effect appeared to be mediated predominately through the hypocapnic vasoconstriction coinciding with PCO₂ level reduction. The results suggest that CPAP should be used cautiously in patients with unstable cerebral hemodynamics.     

Insomnia symptoms influence CPAP compliance

Purpose

The aim of this study is to determine parameters which influence 6-month compliance of continuous positive airway pressure therapy (CPAP) in patients with obstructive sleep apnea syndrome (OSAS).

Methods

This prospective study investigated 73 patients (24 females) with OSAS and medical indication for CPAP therapy: age 55.1?±?11.5 years, body mass index (BMI) 30.8?±?5.0 kg/m2, Apnea–Hypopnea Index (AHI) 39.2?±?26.7/h, Oxygen Desaturation Index (ODI) 33.2?±?25.4/h, minimum O₂ saturation 78.9?±?7.6%. The influence of baseline parameters (demographic and polysomnographic data, sleeping medication intakes, BMI, psychometrics [Epworth Sleepiness Scale, Regensburg Insomnia Scale, Vigilance test and Beck Depression Inventory]) on 6-month compliance was evaluated with a correlation and a linear regression analysis.

Results

The baseline value of the Regensburg Insomnia Scale (RIS) predicts 6-month CPAP compliance (r?=??0.376, R ²?=?0.14, p?<?0.001), although no other baseline parameter correlates. Patients with a compliance of <4 h/night show higher RIS scores, i.e., more insomnia symptoms (17.6?±?8.8) compared to those with ≥4 h/night (12.6?±?6.9; p?<?0.05).

Conclusions

Insomnia symptoms prior to the beginning of CPAP treatment show a negative influence on CPAP compliance. Further studies should clarify, if a treatment of insomnia symptoms leads to a benefit in compliance.     

CRP evolution pattern in CPAP-treated obstructive sleep apnea patients. Does gender play a role?

Background??aim

C-reactive protein (CRP) is directly implicated in atherogenesis and associated cardiovascular morbidity in patients with obstructive sleep apnea (OSA). Effective continuous positive airway pressure (CPAP) treatment has been shown to gradually decrease CRP levels and thus consequently improve disease-related cardiovascular morbidity. However, the influence of gender on the CRP evolution pattern has never been assessed before. The aim of our study was to investigate possible gender differences in CRP evolution in OSA patients 3 and 6?months after the start of effective CPAP treatment.

Methods

The study population consisted of 436 patients (252 males/184 females) with newly diagnosed moderate to severe OSA and good CPAP compliance assessed by a thorough follow up. High-sensitivity C-reactive protein (hs-CRP) was assessed before CPAP initiation and at the third and sixth month of the follow-up period.

Results

C-reactive protein values showed a statistically significant decrease at the third and sixth month of CPAP therapy [initial values 0.79?±?0.65?mg/dL versus 0.70?±?0.52?mg/dL (p?p?p?p?>?0.05). After 6?months?? treatment, CRP decreased significantly in both genders (males from 0.74?±?0.53?mg/dL to 0.28?±?0.32?mg/dL, p?p?Conclusion Our results suggest a delay in the normalization of CRP levels in females despite effective CPAP treatment. A time period of at least 6?months appeared to be required in women in order to reduce CRP levels and consequent cardiovascular risk. In contrast, CPAP??s protective role in males is achieved at an earlier time point. Gender-related hormonal and genetic factors may influence the above CRP evolution pattern.     

Pulse transit time: validation of blood pressure measurement under positive airway pressure ventilation

Purpose

The objective of the present study was to validate noninvasive, continuous blood pressure (BP) measurement using pulse transit time (PTT) to represent absolute values and detect BP changes under continuous positive airway pressure (CPAP) treatment.

Methods

We applied CPAP to 78 patients of a cardiological sleep lab using 0 (baseline), 4, 8, and 12?cmH₂O for 10?min at every level and measured BP simultaneous via PTT-based method and standard oscillometric method (OM).

Results

Quality of signal perception was acceptable to convert PTT into BP values in 64 patients (82%). When comparing both methods, we found a strong linear correlation of systolic and diastolic BP (baseline, r?=?0.94 for systolic BP; r?=?0.95 for diastolic BP, p?<?0.001) while no significant differences between absolute values obtained with OM and PTT measurement. Mean bias at baseline was 4.1?±?3.2?mmHg for systolic BP and 2.3?±?2.2?mmHg for diastolic BP. With increasing CPAP levels, PTT and OM measurements differed continuously up to a systolic difference of 6.6?±?4.9?mmHg and a diastolic difference of 4.4?±?3.5?mmHg. There was no definite trend of PTT method to either over- or underestimate BP.

Conclusions

We found that PTT- and OM-based BP results are closely correlated while applying CPAP over a period of 40?min. With higher CPAP level, bias between both methods increased.     

Auto bi-level pressure relief–PAP is as effective as CPAP in OSA patients—a pilot study

Purpose

Continuous positive airway pressure (CPAP) is the therapy of choice for the treatment of obstructive sleep apnea (OSA). Not all patients can use CPAP therapy with adequate compliance. There is a need to develop more comfortable modes. Auto bi-level Pressure Relief-Positive Airway Pressure (ABPR-PAP) can be an alternative. We conducted a prospective double-blind, randomised trial to evaluate the efficacy and compliance of ABPR-PAP compared with CPAP in OSA patients.

Methods

We included 35 CPAP naive patients (age 53.3?±?10.3?years, BMI 31.0?±?5.0?kg/m², ESS 10.0?±?4.2) diagnosed with moderate to severe OSA who underwent a successful CPAP titration. Patients were randomised into the CPAP or the ABPR-PAP treatment group. We used the same device (BIPAP? Auto, Philips Respironics) for CPAP or ABPR-PAP. Apnea?Chypopnea index (AHI) was determined using polysomnography before (AHI 40.6?±?18.3 per hour) and after treatment.

Results

Eighteen patients received CPAP and the remaining 17 received APBR-PAP. Groups were similar in terms of demographics and OSA severity. There were no serious adverse events during the trial. CPAP was fixed by a sleep expert and ABPR-PAP varied (range 5?C15?cmH₂O). AHI decreased in the CPAP group to 6.4?±?5.7 per hour and in the ABPR-PAP group to 4.8?±?3.6 per hour in the first night (N?=?35). After 3?months, the AHI decreased in the CPAP group to 4.4?±?5.3 per hour and in the ABPR-PAP group to 2.6?±?3.8 per hour (N?=?32). Differences between the groups were not statistically significant. There were no differences in compliance.

Conclusions

ABPR-PAP is a promising new ventilation mode that enables effective treatment of OSA patients.     

Nasal versus oronasal continuous positive airway pressure masks for obstructive sleep apnea: a pilot investigation of pressure requirement, residual disease, and leak

Purpose

This single-blinded, randomized, controlled pilot study aimed to investigate whether there is a difference between nasal and oronasal masks in therapeutic continuous positive airway pressure (CPAP) requirement, residual disease, or leak when treating obstructive sleep apnea (OSA) and if differences were related to measures of upper airway size.

Methods

Patients with severe OSA currently using CPAP at ??4?h/night with a nasal mask were examined (including Mallampati scale, incisal relationship, and mandibular protrusion) and then randomized to receive auto-positive airway pressure (PAP) or fixed CPAP at a manually titrated pressure for 1?week each at home, with immediate crossover. Within each week, a nasal mask and two oronasal masks were to be used for two or three nights each in random order. Data were downloaded from the device.

Results

Twelve patients completed the trial (mean ± SD AHI 59.8?±?28.6 events/h; CPAP 11.1?±?3.2?cmH₂O; BMI 37.7?±?5.0?kg/m²). During auto-PAP, the median 95th percentile pressure delivered with all masks was within 0.5?cmH₂O (p?>?0.05). During CPAP, median residual AHI was 0.61 (IQR?=?1.18) for the nasal mask, 1.70 (IQR?=?4.04) for oronasal mask 1, and 2.48 (IQR?=?3.74) for oronasal mask 2 (p?=?0.03). The 95th percentile leak was lowest with the nasal mask during both CPAP and auto-PAP (both p?Conclusions In obese OSA patients changing from a nasal to oronasal mask increased leak and residual AHI but did not affect the therapeutic pressure requirement. The findings of the current study highlight mask leak as the major difficulty in the use of oronasal masks.     

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.     

Oronasal masks require higher levels of positive airway pressure than nasal masks to treat obstructive sleep apnea

Purpose

The purpose of this study was to compare the therapeutic pressure determined by an automated CPAP device (AutoCPAP) during the titration period, between nasal and oronasal mask and the residual apnea-hypopnea index (AHI) on a subsequent poligraphy performed with the established therapeutic CPAP.

Methods

As a retrospective study, 109 subjects with moderate and severe obstructive sleep apnea-hypopnea (apnea-hypopnea index?≥?15 events/h) were studied. CPAP titration was performed using an auto-titrating device.

Results

There was significant difference in the mean pressure delivered with autoCPAP between the group of patients using the nasal mask (mean 10.0 cmH₂O?±?2.0 SD) and the group which used the oronasal mask (mean 11.2 cmH₂O?±?2.1) (p?p?r?=?0.245, p 0.008).

Conclusions

Therapeutic CPAP level for OSAH is higher when administered via oronasal mask, leaving more residual events. These findings suggest that nasal mask should be the first choice for OSAH treatment.     

Willingness score obtained after a short CPAP trial predicts CPAP use at 1 year

Purpose

To predict continuous positive airway pressure (CPAP) adherence at 1 year.

Methods

We followed consecutive OSA patients scheduled for CPAP initiation for 1 year. Patients completed a self-efficacy questionnaire (5 = low, 25 = high score) before CPAP initiation. After CPAP initiation, we enquired about patients’ satisfaction in CPAP trial and their eagerness and willingness to continue CPAP therapy (0 = unsatisfied, uneager, or refused CPAP; 100 = satisfied, eager, or willing to continue CPAP treatment).

Results

Of the 580 patients we followed, 377 continued CPAP therapy beyond 1 year. A low willingness score (<50) was expressed by 77 patients but only 7 of them used CPAP >4 h daily at 1 year, yielding a specificity of 97 % in predicting CPAP failure. At 1 year, patients with a self-efficacy score >20, expressed prior to CPAP initiation, used CPAP more often than the patients with a score <20 (average use 4.4?±?2.2 h vs. 3.7?±?2.3 h, p?<?0.001).

Conclusions

A low score of willingness to continue CPAP therapy after a short trial predicts CPAP failure and poor CPAP adherence at 1 year.     

Effects of obstructive sleep apnea severity on serum lipid levels in Greek children with snoring

Background

Although obstructive sleep apnea (OSA) is related to dyslipidemia in adults, limited data are available regarding its effects on serum lipids during childhood. Aim of this study was to assess the potential relationships between severity of OSA and cholesterol or triglyceride levels in a cohort of Greek children.

Methods

Data from children with snoring who underwent polysomnography and complete serum lipids measurements during a specified study period were analyzed retrospectively.

Results

Overall, obese children (n?=?261) had lower HDL cholesterol levels than non-obese subjects (n?=?113) (49.6?±?10.5 vs. 53.9?±?11.4 mg/dL; p?=?0.001) and higher triglyceride concentrations (69.8?±?32.2 vs. 63.2?±?27 mg/dL; p?=?0.041). Non-obese subjects with moderate-to-severe OSA did not differ in triglycerides, total, and LDL cholesterol concentrations but had lower HDL cholesterol, when compared to non-obese children with primary snoring/mild OSA (50.4?±?13.1 vs. 54.9?±?10.7 mg/dL; p?=?0.008). The risk for having low HDL cholesterol (??40 mg/dL) was threefold higher in non-obese subjects with moderate-to-severe OSA than in those with primary snoring/mild OSA, even after adjustment for age and gender [OR?=?3.44 (95% CI 1.44 to 8.24; p?=?0.006)]. Concentrations of serum lipids in obese children were not associated with severity of OSA. HDL cholesterol was 48.5?±?8.7 mg/dL in subjects with moderate-to-severe OSA and 50.0?±?11.1 mg/dL in children with primary snoring/mild OSA (p?=?0.519).

Conclusions

HDL cholesterol levels are inversely related to severity of OSA in non-obese children with snoring.     

Functional short- and long-term effects of nasal CPAP with and without humidification on the ciliary function of the nasal respiratory epithelium

Purpose

Continuous positive airway pressure (CPAP) is the gold standard in the treatment of obstructive sleep apnea (OSA), but its impact on ciliary function is unclear to date. Furthermore, CPAP is associated with numerous side effects related to the nose and upper airway. Humidified CPAP is used to relieve these symptoms, but again, little is known regarding its effect on ciliary function of the nasal respiratory epithelium.

Methods

In this prospective, randomized, crossover trial, 31 patients with OSA (AHI >15/h) were randomized to two treatment arms: nasal continuous positive airway pressure (nCPAP) with humidification or nCPAP without humidification for one night in each modality to assess short-term effects of ciliary beat frequency (CBF) and mucus transport time (MTT) and consecutively for 8 weeks in each modality to assess long-term effects in a crossover fashion.

Results

The baseline CBF was 4.8?±?0.6 Hz, and baseline MTT was 540?±?221 s. After one night of CPAP with and without humidification, ciliary function increased moderately yet with statistical significance (p <0.05). The short-term groups with and without humidification did not differ statistically significant. Regarding long-term effects of CPAP, a statistically significant increase in ciliary function above the baseline level and above the short-term level was shown without humidification (7.2?±?0.4 Hz; 402?±?176 s; p <0.01). The increase above baseline level was even more pronounced with humidification (9.3?±?0.7 Hz; 313?±?95 s; p <0.01). There was a statistically significant difference between both groups at long-term assessment with regard to CBF (p <0.01).

Conclusions

Independent of airway humidification, nCPAP has moderate effects on short-term ciliary function of the nasal respiratory epithelium. However, a significant increase in ciliary function—both in terms of an increased CBF and a decreased MTT—was detected after long-term use. The effect was more pronounced when humidification was used during nCPAP.     

The influence of nasal abnormalities in adherence to continuous positive airway pressure device therapy in obstructive sleep apnea patients

Background

The few studies that examine the effect of nasal abnormalities on continuous positive airway pressure device (CPAP) adherence are controversial. The aim of this study was to evaluate the contribution of nasal abnormalities in CPAP adherence.

Methods

We included patients with moderate to severe OSA. The patients were submitted to rhinoscopy, nasofibroscopy, nasal inspiratory peak flow, and acoustic rhinometry. The patients who used a CPAP for 4 h or more per night for at least 70 % of the nights over a 6-month period were considered to have good adherence.

Results

Thirty-four patients finished the study. Eleven (33.4 %) were female and 23 (67.6 %) were male. Sixteen (47.1 %) patients had good adherence. The body mass index (p?=?0.030), neck circumference (p?=?0.006), and apnea–hypopnea index (p?=?0.032) were higher, and the oxyhemoglobin saturation minimum was lower (p?=?0.041) in the good adherence group. Nasal parameters showed no differences between good and poor adherence groups. In Spearman’s correlation, surprisingly, there was a negative correlation between the highest number of hours of CPAP use with smaller values of nasal minimal cross-sectional areas in the supine position (r, 0.375; p?=?0.029). In the linear regression model, the nasal findings that predicted increased of the CPAP use were the following: lower scores of nasal symptoms (p?=?0.007) and lower nasal volume in supine position (p?=?0.001).

Conclusions

The majority of the nasal parameters evaluated in this study did not influence CPAP adherence.