Automatic CPAP titration with different self-setting devices in patients with obstructive sleep apnoea.

Autotitrating continuous positive airway pressure (CPAP) devices automatically adjust the pressure according to upper airway obstructions. The aim of this study was to compare the treatment effects of different automatic CPAP devices (AutoSet, Horizon and Virtuoso) with conventional CPAP in patients with obstructive sleep apnoea independently of financial manufacturer support. Twelve male patients with obstructive sleep apnoea were submitted to a crossover study protocol with overnight polysomnography for 6 consecutive nights. After diagnostic polysomnography, the CPAP pressure was manually titrated. Over the next 4 nights, the patients were treated with any one of the three automatic CPAP devices or fixed CPAP in random order. The apnoea/hypopnoea index on the diagnostic night was 67.3+/-21.7 events h(-1), and was significantly reduced to 0.7+/-1.2, 3.0+/-2.9, 2.3+/-2.5 and 12.0+/-13.6 events x h(-1) with the fixed CPAP, AutoSet, Horizon and Virtuoso devices respectively. An apnoea/ hypopnoea index of <5 events h(-1), an indicator of optimal treatment, was achieved in all patients with fixed CPAP and in 10 patients using the Autoset and Horizon devices, but in only six of the 12 using the Virtuoso. The mean pressure was significantly lower with the AutoSet and Virtuoso devices, but not with the Horizon as compared to fixed CPAP. The maximum pressure was significantly higher with the Horizon. It is concluded that automatic continuous positive airway pressure devices produce a significant reduction in apnoea/hypopnoea index; however, there is considerable difference in the efficacy of the various devices.     

Is automatic CPAP titration as effective as manual CPAP titration in OSAHS patients? A meta-analysis

Purpose  

It is costly and time-consuming to conduct the standard manual titration to identify an effective pressure before continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) patients. Automatic titration is cheaper and more easily available than manual titration. The purpose of this systematic review was to evaluate the effect of automatic titration in identifying a pressure and on the improvement of apnea/hyponea index (AHI) and somnolence, the change of sleep quality, and the acceptance and compliance of CPAP treatment, compared with the manual titration.     

Nasal CPAP in nonapneic nocturnal asthma

Nasal CPAP has been shown to improve nocturnal asthma in those patients with associated sleep apnea. We studied seven nonapneic, nonsnoring asthmatics to determine the effect of CPAP in this patient population. On the CPAP night vs the baseline night, there was a significant worsening of sleep architecture. This included increased awake time and decreased REM sleep. For the group, the overnight decrement in FEV1 was not improved. Of interest, two patients did have a marked improvement in FEV1 associated with improved oxygen saturation on the CPAP night. These individuals were restudied only on supplemental oxygen. This intervention also improved the overnight FEV1 and allowed the patients to have better sleep compared to the CPAP night. We concluded that CPAP is associated with disrupted sleep architecture in nonapneic asthmatics and nocturnal oxygen desaturation may play a role in the development of nocturnal asthma.     

The use of a predicted CPAP equation improves CPAP titration success

Titration of continuous positive airway pressure (CPAP) is performed to determine the CPAP setting to prescribe for an individual patient. A prediction equation has been published that could be used to improve the success rate of CPAP titrations. The goals of this study were: (1) to test the hypothesis that the use of the prediction equation would achieve a higher rate of successful CPAP titrations; (2) to validate the equation as an accurate predictor of the prescribed CPAP setting and determine the factors that influence the accuracy of the prediction equation. A total of 224 patients underwent CPAP titration prior to using the equation, with a starting pressure of 5 cm H₂O. A total of 192 patients underwent CPAP titration using the equation-predicted CPAP level as the starting pressure (median starting pressure of 8 cm H₂O [interquartile range 7, 10 cm H₂O]). The percentage of successful studies, as defined by a 50% decrease in the apnea–hypopnea index (AHI) and a final AHI 10 cm H₂O, increased from 50% to 68% (p<0.001), while the number of patients who were prescribed a CPAP level that had not been tested decreased from 22% to 5% (p<0.001). The equation was not accurate in predicting the prescribed level of CPAP, with only 30.8% of the patients with a prescribed pressure 3 cm H₂O of the predicted pressure. Female gender was the only predictor of a prescribed pressure 3 cm H₂O from the predicted pressure (odds ratio 3.45, 95% confidence intervals 1.67, 7.13, p<0.001). A CPAP prediction equation modestly increases the rate of successful CPAP titrations by increasing the starting pressure of the titration. The equation does not accurately predict the prescribed CPAP level, reaffirming the need for a titration study to determine the optimal prescribed level in a given patient.     

Predictive equations for CPAP titration in OSAS patients

Background  

Continuous positive airway pressure (CPAP) is the elective treatment of obstructive sleep apnea. The therapeutic level of CPAP is generally established by manual titration or an auto CPAP device, but an alternative way involves the use of predictive formulas. The aim of the present study was to test the difference between mathematical equations and CPAP or auto CPAP in terms of therapeutic pressure.     

Effects of heated humidifier during CPAP titration in the cool sleeping environment

Sleep and Breathing -     

Predicting optimal CPAP by neural network reduces titration failure: a randomized study

Purpose  

Continuous positive airway pressure (CPAP) is considered the standard therapy for obstructive sleep apnea syndrome. In the absence of standard protocol, CPAP titration may be unsuccessful. The purpose of this study was to test the hypothesis that application of an artificial neural network (ANN) to CPAP titration would achieve an optimal CPAP pressure within a shorter time interval and would lead to a decrease in CPAP titration failure.     

Accuracy of an unattended home CPAP titration in the treatment of obstructive sleep apnea

Treatment of sleep apnea-hypopnea syndrome (SAHS) by fixed continuous positive airway pressure (CPAP) requires an in-laboratory titration procedure to determine the effective pressure level (Peff ). We recently reported that one auto-CPAP machine can be used without titration study allowing Peff determination. The aim of this study was to evaluate the accuracy of an auto CPAP trial at home. A 1- or 2-wk automatic CPAP trial was done at home in 40 patients by estimating the reference pressure (Pref ) to be set and a Pref + 3 cm H(2)O/-4 cm H(2)O pressure interval. Peff was then determined according to the percentage of CPAP time that was spent 相似文献   

Randomized short-term trial of two autoCPAP devices versus fixed continuous positive airway pressure for the treatment of sleep apnea

We evaluated the efficacy of two different continuous positive airway pressure devices with automatic mask pressure adjustment (autoCPAP) in comparison with fixed CPAP in treating obstructive sleep apnea syndrome in 29 patients. The mean (+/- SE) apnea-hypopnea index was 46 +/- 4 per hour and the Epworth score was 14.2 +/- 0.7. Patients were treated over three consecutive 1-month periods with three regimens in random order: an autoCPAP device responding to apnea-hypopnea and snoring, another autoCPAP device responding to snoring and changes in flow contour, and fixed CPAP at the 90th pressure percentile titrated by autoCPAP over 2 weeks. Allowed pressure in the autoCPAP mode was 4 to 15 cm H2O. At the end of each treatment period, symptoms, quality of life, vigilance, and nocturnal breathing disturbances were evaluated. All three treatment modalities improved symptoms, quality-of-life domains, and apnea-hypopnea index significantly and to a similar degree. Mean (+/- SE) maintenance-of-wakefulness time increased by 4.5 +/- 1.8, 6.0 +/- 1.5, and 6.1 +/- 1.4 minutes with DeVilbiss AutoAdjust LT, AutoSet T, and fixed-pressure CPAP, respectively (p<0.001 vs. baseline, p=not significant for comparisons among the three modalities). We conclude that both autoCPAP devices were equally effective as fixed-pressure CPAP in improving major outcomes during short-term therapy of sleep apnea.     

The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients

Purpose

The aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE).

Methods

A total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels.

Results

A significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P?<?0.001, P?<?0.001, P?<?0.001, and P?<?0.001, respectively, by Spearman correlation). Patients with concentric collapse of the velum or lateral oropharyngeal collapse were associated with a significantly higher CPAP titration level (P?<?0.001 and P?=?0.043, respectively, by nonparametric Mann-Whitney U test; P?<?0.001 and P?=?0.004, respectively, by Spearman correlation). No significant association was found between the CPAP titration level and any other collapse at the tongue base or epiglottis.

Conclusions

By analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

     

夜间经鼻面罩持续正压辅助通气治疗中枢性低通气

报告４例不同原因所致的中枢性低通气病人夜间应用经鼻面罩持续正压通气的疗效反应。４例病人分别于治疗前、吸氧２Ｌ／ｍｉｎ及应用通气治疗后行多导睡眠图检查比较夜间低通气及血氧情况，结果示单纯吸氧不能明显改善低通气次数和低氧情况，最低氧饱和度均＜５０％，低通气指数３例仍＞２０ｂ／ｈ（正常值＜５ｂ／ｈ），另１例为６４ｂ／ｈ；予以持续正压通气机通气治疗，压力调至６～１２ｃｍＨ２Ｏ（１ｃｍＨ＿２Ｏ＝０．０９８ｋＰａ）时，低通气指数及低氧血症明显改善，最低氧饱和度均＞７０％，Ｐ＜０．００１，低通气指数均＜７ｂ／ｈ，Ｐ＜０．０１。结论：夜间应用鼻面罩持续正压通气治疗中枢性低通气的初步结果示疗效显著。     

Reduced nocturnal fall in blood pressure,assessed by two ambulatory blood pressure monitorings and cardiac alterations in early phases of untreated essential hypertension

To investigate whether in recently diagnosed essential hypertensives a reduced nocturnal fall in blood pressure (BP), established on the basis of two 24-h ambulatory blood pressure monitorings (ABPM) is related to a greater cardiovascular damage. In all, 355 consecutive, recently diagnosed, never-treated essential hypertensives referred for the first time to our outpatient clinic were included in the study. Each patient underwent the following procedures: (1) two 24-h ABPMs performed within 3 weeks, (2) 24-h urinary collection for microalbuminuria, (3) nonmydriatic photography of ocular fundi, (4) echocardiography, (5) carotid ultrasonography. We defined nondipping profile as a night-day systolic and diastolic fall < or =10 % (mean of two ABPMs). A dipper BP profile was found in 238 patients, whereas in 117 patients a nondipper profile was present. The two groups were similar for age, gender, body mass index, smoking habit, clinic BP, 48-h BP and heart rate, while, by definition, night-time systolic and diastolic BP were significantly higher in nondippers than in dippers (130/81 vs 121/74 mmHg, P < 0.0001).The prevalence of left ventricular hypertrophy (LVH) defined by four different criteria: (a) LV mass index (LVMI) > or = 125 g/m(2) in both genders; (b) LVMI > or = 134 gm(2) in men and > or = 110 in women; (c) LVMI> or = 125 g/m(2) in men and > or = 110 g/m(2) in women; (d) LVMI > or = 51 g/m(2.7) in men and > or = 47 g/m(2.7) in women was significantly higher in nondippers than in dippers (a: 12 vs 7%, P < 0.05; b: 16 vs 7%, P < 0.01; c: 20 vs 11%, P < 0.01; d: 35 vs 23% P < 0.02) and this finding was associated with a significant increase in aortic root and left atrium dimensions. There were no differences between the two groups in the prevalence of carotid and retinal changes and microalbuminuria. In conclusion our findings suggest that never-treated hypertensives with a reduced BP fall in the night time, defined on the basis of two ABPMs, have a higher prevalence of TOD than dippers, in terms of echocardiographic LVH. In this population setting, cardiac structural alterations are a more sensitive marker of the impact of the nocturnal BP load on cardiovascular system than other extracardiac signs of TOD.     

正压通气对阻塞性睡眠呼吸暂停综合征夜间室性心律失常的作用

目的 探讨阻塞性睡眠呼吸暂停综合征(OSAS)严重程度与夜间室性心律失常间的关系以及经鼻持续气道正压通气(nCPAP)对室性心律失常的作用.方法 197例OSAS者按呼吸紊乱指数分轻、中、重3组,观察夜间室性心律失常发生率,比较组间差异性,并观察各组行nCPAP前后宣性心律失常发生率的变化.结果 OSAS者夜间室性心律失常发生率随着病情加重而明显增加、室性心律失常增多.治疗后各组夜间室性心律失常发生率较治疗前显著下降.结论 随着OSAS者病情加重,夜间室性心律失常发生率增多,nCPAP能有效降低OSAS者夜间室性心律失常发生率.     

Automatic pressure titration with APAP is as effective as manual titration with CPAP in patients with obstructive sleep apnea

BACKGROUND: The optimal approach to initiate positive-pressure therapy in patients with obstructive sleep apnea is still debated. Current options are autotitrating positive airway pressure (APAP) or manual titration with continuous positive airway pressure (CPAP). Procedures differ by parameters and by algorithms used for adapting pressure. OBJECTIVES: To evaluate the efficacy of attended automatic titration in a randomized crossover study compared with manual titration over 2 nights where the sequence of the titration mode was changed. Therapy outcome was controlled after 6 weeks. METHODS: 21 sleep apnea patients were treated using manual CPAP versus automatic APAP titration. The mode used during the 2nd night was continued for 6 weeks. Cardiorespiratory polysomnography, Epworth Sleepiness Scale (ESS), SF-36 score and compliance were assessed. RESULTS: Apnea-hypopnea index reduction was equally effective at similar effective pressure independent of the titration mode. If APAP was applied during the 1st night, total sleep time was longer (384 vs. 331 min, p < 0.01) and sleep efficacy was higher (91 vs. 81%, p < 0.01) than after starting with manual titration with CPAP. Compliance was comparable in both groups (4.6 +/- 1.9 h). The ESS improved in both groups (from 12.9 to 6.5). SF-36 scores and therapeutic pressure did not much change. CONCLUSIONS: Taking the sequence of titration into account, we found equal effectiveness of CPAP and APAP. Sleep quality was better with initial application of APAP - which favors attended automatic titration if only 1 titration night is possible. Both modes are comparable after 6 weeks regarding therapeutic pressure, efficacy, compliance and quality of life.     

Author response to: Effects of heated humidifier during CPAP titration in the cool sleeping environment

Sleep and Breathing -     

Use of heated humidification during nasal CPAP titration in obstructive sleep apnoea syndrome.

Nasal symptoms associated with the use of nasal continuous positive airway pressure (nCPAP) in obstructive sleep apnoea (OSA) can adversely impact on patients' tolerance, acceptance and adherence to nCPAP therapy. Regular use of heated humidification is effective in alleviating these symptoms and improve patient comfort. In a randomised, parallel, double-blinded, controlled study, the present authors examined the use of heated humidification during a single night laboratory nCPAP titration in untreated OSA patients and its effect on nasal symptoms, nasal airway resistance (NAR), effective pressure and treatment tolerability and acceptance. Baseline characteristics of subjects (n=70) receiving placebo and humidification were (mean+/-sem): age 51.2+/-2.2 versus 50.6+/-1.6 yrs; body mass index 33.6+/-0.9 versus 35.2+/-0.9 kg.m-2; Epworth Sleepiness Scale 10.8+/-1.0 versus 11.3+/-0.7; and apnoea-hypopnoea index 43.5+/-4.6 versus 44.4+/-4.1 events.h-1. Total inspiratory NAR, before (0.36+/-0.09 (placebo) versus 0.33+/-0.09 kPa.L-1.s-1) and after nCPAP (0.47+/-0.11 versus 0.29+/-0.04 kPa.L-1.s-1) were not significantly different between the groups. No difference was found in the frequency and severity of nasopharyngeal symptoms, therapeutic pressure and subjective response to nCPAP. In conclusion, heated humidification during the initial nasal continuous positive airway pressure titration offers no additional benefit in nasal physiology, symptoms or subjective response to nasal continuous positive airway pressure, and, therefore, should not be routinely recommended.     

Prader-Willi syndrome with sleep disordered breathing: effect of two years nocturnal CPAP

We report a case of a 3-year-old child with Prader-Willi syndrome who had severe sleep disordered breathing with daytime hypersomnolence. His daytime blood gases showed type II respiratory failure. He was effectively treated with continuous positive airway pressure (CPAP) and has used this form of therapy for 2 years now with improvement in daytime somnolence, improved mental acuity and normalisation of daytime blood gases.     

Comparison of conventional nighttime with automatic or manual daytime CPAP titration in unselected sleep apnea patients: study of the usefulness of daytime titration studies

Daytime CPAP titration studies with full polysomnography have been successfully performed in patients with severe sleep apnea-hypopnea syndrome (SAHS). The implementation of daytime studies in unselected SAHS patients could help to reduce the waiting lists for CPAP titrations. The main purpose of this study was to compare the effectiveness of conventional versus manual or automatic daytime CPAP titration in unselected patients with SAHS. Ninety-three consecutive patients with SAHS in whom CPAP was indicated were assigned to conventional titration or to manual or automatic (AutoSet) daytime CPAP titration, after sleep deprivation. The number of valid studies, sleep architecture, final pressure selected and mean pressure in the different sleep stages were compared. Changes in sleepiness (Epworth sleepiness score) and hours of CPAP use were assessed after 3 months of treatment. Four patients did not sleep (3 AutoSet, 1 conventional daytime groups). Sleep latency was shorter during automatic daytime titration whereas REM latency was shorter in daytime studies; the percentage of sleep stages was similar during all types of titration. CPAP requirements were significantly higher during REM sleep in conventional and manual daytime titrations while mean pressure was unchanged throughout sleep stages during AutoSet titration. CPAP pressure selected with conventional or daytime manual titration (7.5(2.2) cm H2O and 7.4(1.5) cm H2O, ns) were significantly lower (P< 0.001) than with AutoSet (9.4(1.6) cm H20. All groups showed similar decrease of sleepiness and hours of use of CPAP at 3 months of follow-up. Automatic and manual daytime PSG studies after sleep deprivation are useful for CPAP titration in unselected patients with SAHS. Pressure selected with AutoSet is significantly higher than with conventional daytime or nighttime titration, although not significant in terms of treatment compliance and symptom improvement.     

Role of nocturnal hypoxaemia in the genesis of systemic hypertension

Two groups of patients with nocturnal arterial oxygen desaturation were compared. The degree of nocturnal oxygen desaturation, as reflected by the percentage of total sleep time spent with an oxygen saturation less than 90 and 80%, was similar in patients with the obstructive sleep apnoea syndrome (OSAS) and in those with nocturnal hypoventilation (NH) secondary to restrictive chest wall disease. Systemic hypertension was present in 16 of the 24 OSAS patients but in only 6 of the 24 with NH (p less than 0.005). Multiple regression analysis demonstrated that this difference remained significant even after adjustment for age, sex, weight and history of smoking. It is likely that factors other than nocturnal hypoxaemia are important in the aetiology of systemic hypertension in patients with sleep-related breathing disorders.