持续气道内正压治疗阻塞性睡眠呼吸暂停低通气综合征

持续气道内正压（CPAP）通气是治疗阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的主要方法。OSAHS患者经CPAP治疗后嗜睡改善、血压下降、心脑血管病变的发生率降低，生活质量提高。CPAP治疗OSAHS的主要机制是气道内正压使上气道撑开^[1]，并且由于呼气时气道内正压使肺残气增高，也有助于维持上气道的畅通。     

Continuous positive airway pressure treatment on blood pressure rhythm in hypertension patients with obstructive sleep apnea

<正>Objective To investigate the effect of continuous positive airway pressure(CPAP) on blood pressure and blood pressure rhythm in hypertensive patients with sleep apnea syndrome.Methods Hypertensive patients with obstructive sleep apnea syndrome consecutively recruited between 2020 and 2022 were randomly divided into two groups,the CPAP group and the control group.Both groups were routinely treated with antihypertensive drugs,and patients in the CPAP group were additionally treated with C...     

连续气道正压通气对阻塞性睡眠呼吸暂停患者血管内皮功能的影响

目的检测阻塞性睡眠呼吸暂停低通气综合征（OSAHS）患者血清一氧化氮（NO）、内皮素-1（ET-1）、血管性血友病因子（vWF）及肱动脉内径变化;评估连续气道正压通气（CPAP）对此类患者血管内皮功能的影响。方法选择OSAHS患者55例和健康对照组55例,分别测定所有受试者血清NO、ET-1、vWF水平,同时使用多普勒彩超测定肱动脉内径变化。对OSAHS患者使用CPAP治疗3月后再次测定以上指标。结果治疗前OSAHS患者血清NO水平和肱动脉内径变化率明显低于对照组（P均〈0．01）;血清ET-1和vWF水平明显高于对照组（P均〈0．01）。NO水平和肱动脉内径变化率与呼吸紊乱指数呈显著负相关（r分别为-0．621,-0．581,P〈0．01）,与最低血氧饱和度正相关（r分别为0．516,0．613,P〈0．01）;ET-1和vWF水平与呼吸紊乱指数呈正相关（r分别为0．534,0．559,P均〈0．01）,与最低血氧饱和度均呈负相关（r分别为-0．479,-0．637,P均〈0．01）。肱动脉内径变化率与NO呈正相关,与ET-1和vWF水平呈负相关（r分别为0．681,-0．541和-0．513,P均〈0．01）。结论OSAHS患者早期已存在血管内皮功能损害,与呼吸紊乱指数和低氧相关;CPAP能够改善患者血管内皮功能。     

Continuous positive airway pressure and lung inflation in sleep apnea patients.

BACKGROUND: It was shown in normals that an important decrease in upper airway resistance can be obtained with continuous positive airway pressure (CPAP). It was suggested that lung inflation in patients with sleep apnea syndrome (SAS) could also be a mechanism of action of CPAP. OBJECTIVE: In the present study we wanted to evaluate the effects of nocturnal CPAP on the daytime lung function pattern in patients with SAS. METHODS: We measured arterial blood gases and possible changes in static lung volumes in 57 SAS patients (37 with normal lung function, 10 with COPD and 10 with restrictive lung disease) after at least one month of CPAP therapy. RESULTS: A significant increase in PaO(2) (from 79 to 84 mm Hg, p = 0.01) and a decrease in AaDO(2) (from 23 +/- 1 to 16 +/- 1, p < 0.01) was only observed in SAS patients with normal lung function. This improved gas exchange was parallelled by a small but non significant change in the FRC (from 96.5 +/- 3.2 to 105.4 +/- 3.7%pred, p = 0.07) and TLC (from 101.3 +/- 1.7 to 104.1 +/- 1.4%pred, p = 0.15). Similar changes in TLC and FRC were also observed in SAS patients with obstructive and restrictive lung disease. CONCLUSIONS: Chronic nocturnal CPAP therapy can improve daytime gas exchange and may influence lung inflation during the daytime. The small changes seem to be a functional effect but of no clinical relevance.     

Continuous positive airway pressure treatment improves pulmonary hemodynamics in patients with obstructive sleep apnea.

Daytime pulmonary hypertension (PH) is relatively common in obstructive sleep apnea (OSA) and is thought to be associated with pulmonary vascular remodeling (PRm). The extent to which PH is reversible with treatment is uncertain. To study this, we measured pulmonary hemodynamics (Doppler echocardiography) in 20 patients with OSA (apnea-hypopnea index [AHI] 48.6 +/- 5.2/h, mean +/- SEM) before and after 1 and 4 mo of CPAP treatment (compliance 4.7 +/- 0.5 h/night). Patients had normal lung function, and no cardiac disease or systemic hypertension. Doppler studies were performed at three levels of inspired oxygen concentration (11%, 21%, and 50%) and during incremental increases in pulmonary blood flow (10, 20, and 30 microg/kg/min dobutamine infusions). Treatment resulted in a decrease in pulmonary artery pressure (Ppa, 16.8 +/- 1.2 mm Hg before CPAP versus 13.9 +/- 0.6 mm Hg after 4 mo CPAP, p < 0.05) and total pulmonary vascular resistance (231.1 +/- 19.6 versus 186.4 +/- 12.3 dyn. s. cm(-)(5), p < 0.05). The greatest treatment effects occurred in the five patients who were pulmonary hypertensive at baseline. The pulmonary vascular response to hypoxia decreased after CPAP (DeltaPpa/DeltaSa(O(2)) 10.0 +/- 1.6 mm Hg before versus 6.3 +/- 0.8 mm Hg after 4 mo CPAP, p < 0.05). The curve of Ppa versus cardiac output (Q), derived from the incremental dobutamine infusion, shifted downward in a parallel fashion during treatment. Systemic diastolic blood pressure also fell significantly. Improvements in pulmonary hemodynamics were not attributable to changes in left ventricular diastolic function or Pa (O(2)). We conclude that CPAP treatment reduces Ppa and hypoxic pulmonary vascular reactivity in OSA and speculate that this may be due to improved pulmonary endothelial function.     

Cerebral hemodynamic changes in obstructive sleep apnea syndrome after continuous positive airway pressure treatment

Background

Patients with obstructive sleep apnea syndrome (OSAS) are at increased risk for cerebrovascular diseases. The underlying mechanisms remain obscure. It may occur through a reduction in cerebral vascular reactivity. Continuous positive airway pressure (CPAP) is effective in reducing the occurrence of apneas. We hypothesized that treatment with CPAP improves cerebral vascular reactivity.

Methods

This is a prospective study with OSAS patients. The apnea test (ApT) was calculated as an increase of mean artery velocity during apnea: [Artery velocity in apnea minus Resting artery velocity]/Resting artery velocity expressed as percentage. After 2 years of CPAP treatment, the test was repeated.

Results

Seventy-six patients represented the study pool. After 2 years of treatment with CPAP, we were able to conduct a reassessment in 65 patients. Of the 65 patients who finished the clinical study, 56 were men, and 9 were women, with an average age of 48.1?±?10.4 years. There was an improvement in the ApT after CPAP treatment (30.8?±?12.1 vs 39.8?±?15.1; p:0.000). The values of cerebral blood flow velocities, diastolic blood pressure in apnea, and basal heart rate decreased.

Conclusions

Cerebral vascular reactivity in OSAS patients measured by ApT improved after 2 years of CPAP.     

持续气道正压通气治疗缺血性脑卒中合并阻塞性睡眠呼吸暂停低通气综合征的疗效评估

目的分析自动压力模式持续气道正压通气(Auto-CPAP)对于急性缺血性脑卒中合并阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)的疗效。方法选择脑卒中患者122例,将合并OSAHS的78例患者随机分为阴性对照组34例和治疗组44例。治疗组在常规治疗基础上,加用Auto-CPAP治疗。将未合并OSAHS的44例脑梗死患者为空白对照组,只接受常规治疗。入院时及治疗后7、14、28d进行美国国立卫生研究院卒中量表(NIHSS)评分和Barthel指数评分以评估疗效。结果与空白对照组比较,阴性对照组和治疗组呼吸暂停低通气指数明显升高(P<0.05);与阴性对照组比较,入院第7、14、28天,治疗组和空白对照组NIHSS评分明显降低,Barthel指数评分明显升高(P<0.05)。入院时与入院第7、14、28天NIHSS评分和Bar-thel指数评分分别做差值,结果显示,Auto-CPAP治疗可使合并OSAHS的脑梗死患者明显获益(P<0.05),而不同程度OSAHS患者的差值结果显示,Auto-CPAP治疗使中重度OSAHS获益更多。结论急性缺血性脑卒中合并OSAHS早期应用Auto-CPAP治疗,能有效改善患者神经功能缺损,中重度OSAHS患者获益更多。     

Continuous positive airway pressure treatment rapidly improves insulin sensitivity in patients with obstructive sleep apnea syndrome

The obstructive sleep apnea syndrome is typically associated with conditions known to increase insulin resistance as hypertension, obesity, and diabetes. We investigated whether obstructive sleep apnea itself is an independent risk factor for increased insulin resistance and whether continuous positive airway pressure (CPAP) treatment improves insulin sensitivity. Forty patients (apnea-hypopnea index > 20) were treated with CPAP. Before, 2 days after, and after 3 months of effective CPAP treatment, hyperinsulinemic euglycemic clamp studies were performed. Insulin sensitivity significantly increased after 2 days (5.75 +/- 4.20 baseline versus 6.79 +/- 4.91 micromol/kg.min; p = 0.003) and remained stable after 3 months of treatment. The improvement in insulin sensitivity after 2 days was much greater in patients with a body mass index less than 30 kg/m2 than in more obese patients. The improved insulin sensitivity after 2 nights of treatment may reflect a decreasing sympathetic activity, indicating that sleep apnea is an independent risk factor for increased insulin resistance. The effect of CPAP on insulin sensitivity is smaller in obese patients than in nonobese patients, suggesting that in obese individuals insulin sensitivity is mainly determined by obesity and, to a smaller extent, by sleep apnea.     

Neuropsychologic symptoms in obstructive sleep apnea improve after treatment with nasal continuous positive airway pressure

To describe the affective changes associated with sleep restoration we assessed psychologic symptoms using the Profile of Mood States questionnaire before and two months after treatment with nasal continuous positive airway pressure (NCPAP) in seven men with obstructive sleep apnea (OSA). The results were compared with those of a control group of patients with OSA who did not receive NCPAP. Two of six mood factors, depression and fatigue, improved significantly following treatment with NCPAP. Total Mood Disturbance (TMD) score was used to assess global mood differences. The mean TMD score for the patients before treatment was 1.7 and during treatment decreased to -7.6 (p less than 0.05). This mean decrease of 9.3 in the TMD score implies generalized improvement in mood. These findings support the opinion that sleep fragmentation and abnormalities of respiration during sleep are at least partially responsible for affective changes seen in sleep apnea. These psychologic disturbances improve after treatment with NCPAP.     

Continuous positive airway pressure treatment improves baroreflex control of heart rate during sleep in severe obstructive sleep apnea syndrome

The role of the arterial baroreflex in the cardiovascular changes associated with the obstructive sleep apnea syndrome (OSAS), and the effect of nasal continuous positive airway pressure (CPAP) treatment on baroreflex function during sleep are unknown. Baroreflex control of heart rate was studied in 29 normotensive patients with OSAS under no treatment, in 11 age-matched control subjects, and in 10 patients at CPAP withdrawal after 5.5 +/- 3.7 (range 3-14) months of treatment. Baroreflex control of heart rate was assessed by "sequence method" analysis of continuous blood pressure recordings (Finapres) obtained during nocturnal polysomnography. In untreated OSAS, baroreflex sensitivity (BRS) was low during wakefulness and non-rapid eye movement (REM) stage 2 sleep compared with control subjects, and correlated inversely with mean lowest Sa(O(2)) and the blood pressure increase after apneas. After CPAP treatment, the apnea-hypopnea index was lower, and mean lowest Sa(O(2)) higher than before treatment. After CPAP, patients were more bradycardic, blood pressure and its standard deviation decreased as Sa(O(2)) improved in non-REM stage 2 sleep, and BRS increased (nocturnal wakefulness: +59%; non-REM stage 2 sleep: +68% over pretreatment values). Our data suggest that baroreflex dysfunction in OSAS may be at least partly accounted for by nocturnal intermittent hypoxemia, and can be reversed by long-term CPAP treatment.     

Continuous positive airway pressure therapy in sleep apnoea

Sleep apnoea is associated with increased mortality and morbidity. The treatment goal is to reduce the neurocognitive and cardiovascular sequelae. CPAP therapy in sleep apnoea is discussed in two parts in the article. The first part will consider CPAP therapy in the more common form of sleep apnoea (i.e. obstructive or mixed sleep apnoea) and the second part will consider CPAP therapy in central sleep apnoea. Alternative positive airway pressure modalities are discussed. CPAP therapy has been extensively studied and it remains the mainstay of treatment in obstructive sleep apnoea, as it is still the most consistently efficacious and safe option. However, its major disadvantage is that it does not confer a cure to this disorder and hence therapy is generally life long with its usual treatment compliance problems. As such, there are continuous improvement strategies. The role of CPAP therapy in central sleep apnoea is more limited. There has been increasing data on the beneficial effect of CPAP on central sleep apnoea/Cheyne-Stokes respiration in congestive heart failure. Evidence for CPAP therapy in sleep apnoea has evolved significantly over the last decade. However, more research and publication of large-scale long-term randomized trials of treatment in sleep apnoea to assess patient-orientated outcomes and preferences are necessary.     

A new predictive model for continuous positive airway pressure in the treatment of obstructive sleep apnea

Background

Numerous mathematical formulas have been developed to determine continuous positive airway pressure (CPAP) without an in-laboratory titration study. Recent studies have shown that style of CPAP mask can affect the optimal pressure requirement. However, none of the current models take mask style into account. Therefore, the goal of this study was to develop new predictive models of CPAP that take into account the style of mask interface.

Methods

Data from 200 subjects with attended CPAP titrations during overnight polysomnograms using nasal masks and 132 subjects using oronasal masks were randomized and split into either a model development or validation group. Predictive models were then created in each model development group and the accuracy of the models was then tested in the model validation groups.

Results

The correlation between our new oronasal model and laboratory determined optimal CPAP was significant, r = 0.61, p < 0.001. Our nasal formula was also significantly related to laboratory determined optimal CPAP, r = 0.35, p < 0.001. The oronasal model created in our study significantly outperformed the original CPAP predictive model developed by Miljeteig and Hoffstein, z = 1.99, p < 0.05. The predictive performance of our new nasal model did not differ significantly from Miljeteig and Hoffstein’s original model, z = ?0.16, p < 0.90. The best predictors for the nasal mask group were AHI, lowest SaO2, and neck size, whereas the top predictors in the oronasal group were AHI and lowest SaO2.

Conclusion

Our data show that predictive models of CPAP that take into account mask style can significantly improve the formula’s accuracy. Most of the past models likely focused on model development with nasal masks (mask style used for model development was not typically reported in previous investigations) and are not well suited for patients using an oronasal interface. Our new oronasal CPAP prediction equation produced significantly improved performance compared to the well-known Miljeteig and Hoffstein formula in patients titrated on CPAP with an oronasal mask and was also significantly related to laboratory determined optimal CPAP.

     

Effect of continuous positive airway pressure vs placebo continuous positive airway pressure on sleep quality in obstructive sleep apnea

STUDY OBJECTIVES: Continuous positive airway pressure (CPAP) therapy has become the treatment of choice for obstructive sleep apnea (OSA). However, the efficacy of CPAP therapy has not been evaluated against a suitable control. We investigated the effectiveness of CPAP therapy in improving sleep quality in patients with OSA. We hypothesized that CPAP improves sleep quality. PATIENTS: Forty-eight CPAP-naive OSA patients were evaluated. None were receiving antihypertensive medications, and none had major medical illnesses. DESIGN: Patients were randomized to receive either CPAP or placebo CPAP (CPAP at an ineffective pressure) for 7 days in a double-blind fashion. Forty-one patients completed the protocol. Sleep quality variables, arousals, sleep arterial oxygen saturation (SaO(2)), and respiratory disturbance index (RDI) were assessed at baseline, after 1 day of treatment, and after 7 days of treatment. Repeated measures analysis of variance was used to evaluate the effects of treatment, time, and the interaction of the two. RESULTS: As expected, CPAP lowered RDI and number of arousals, and increased SaO(2) over time (p = 0.001). Contrary to expectations, both CPAP and placebo CPAP had comparable effects on sleep quality as assessed by sleep architecture, sleep efficiency, total sleep time, and wake after sleep onset time. CONCLUSIONS: This study confirms the effectiveness of CPAP in lowering the number of arousals and the RDI, and in raising SaO(2). However, our data suggest that short-term CPAP is no different than placebo in improving sleep architecture. Further evaluation of the effectiveness of CPAP using a suitable placebo CPAP in prospective randomized studies is needed     

Central sleep apnea reversed by continuous positive airway pressure

Continuous positive airway pressure (CPAP) is an accepted and highly effective method used in the treatment of obstructive sleep apnea (OSA). We have explored the potential utility of CPAP in a patient with sleep apnea without a major contribution of airway obstruction as measured by the usual criteria. The patient showed dramatic clinical and laboratory improvement in central apnea when treated with CPAP. A low level of CPAP (7.5 cm H2O) resulted in the reduction of central apneas from 281 to 32 per night with no significant change in obstructive apneas, which increased from 43 to 59 per night. On a separate night, a higher level of CPAP (12.5 cm H2O) resulted in virtually complete removal of all apneas. Measurement of pharyngeal properties revealed pharyngeal cross-sectional area in the low normal range, but increased pharyngeal compliance. This case illustrates that pharyngeal abnormalities may be present in patients with central sleep apnea, and CPAP may be beneficial in the treatment of this disorder. Although the exact mechanism of action of CPAP in this disorder is unclear, we propose several possibilities that may account for the beneficial effect of CPAP in this patient.