Prediction of continuous positive airway pressure in obstructive sleep apnea

Continuous positive airway pressure (CPAP) prediction formulas can potentially simplify the treatment of obstructive sleep apnea (OSA). However, they can be difficult to derive and validate. We tested a statistical method to derive and validate a CPAP prediction formula using the same sample population. Seventy-six OSA patients underwent polysomnography and CPAP titration. Anthropometric measures, sleep parameters, and the Epworth sleepiness scale (ESS) were evaluated as predictors. All subsets regression was used to determine the optimum number of variables in the model. The Bayes information criterion was used to find the best-fit model. The model was then evaluated by a tenfold cross-validation procedure. Subjects were obese (BMI 31.3 ± 5.4) and had significant daytime somnolence (ESS 11.9 ± 5). Mean respiratory disturbance index (RDI) was 53.5 ± 31.3. The ESS was not predictive of titrated CPAP. The best-fit model included three variables (CPAP_pred = 30.8 + RDI × 0.03 − nadir saturation × 0.05 − mean saturation × 0.2). This model explained 67% of the variance. Our data and the literature suggest that a combination of two to three factors is predictive of titrated CPAP: RDI, oxyhemoglobin saturation, and obesity. Except for RDI, the specific factors vary in each population. A CPAP prediction formula that explains a high proportion of the titrated CPAP variance can be easily derived from parameters measured during the diagnostic work-up of OSA patients using a unique statistical model that allows derivation and validation of the formula in the same test population.     

经鼻持续气道正压通气对阻塞性睡眠呼吸暂停低通气综合征患者睡眠结构近远期的影响

目的　观察经鼻持续气道正压 (nCPAP)通气对阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者睡眠结构近远期的影响。方法　 17例对照者行多导睡眠图 (PSG)监测 ,对 30例经PSG诊断的OSAHS患者行nCPAP治疗 ,治疗第 1夜行PSG监测 ,连续家庭nCPAP治疗 6个月后行第 2次PSG监测 ,分析比较睡眠结构的变化。结果　OSAHS患者治疗前睡眠转换次数、1期、2期睡眠比例较对照组增加 (P <0 0 5 ) ,慢波睡眠期、快动眼 (REM )期比例较对照组低 (P <0 0 5 ) ;nCPAP治疗第 1夜睡眠转换次数、1期、2期睡眠比例较治疗前降低 (P <0 0 5 ) ,慢波睡眠期、REM期比例较治疗前升高 (P <0 0 5 ) ;nCPAP治疗 6个月后睡眠转换次数、1期、2期、慢波睡眠期比例与治疗第 1夜比较差异均无显著性 (P >0 0 5 ) ,而REM期比例较治疗第 1夜降低 (P <0 0 5 )。结论　OSAHS患者睡眠转换次数明显增多 ,1期睡眠增加而REM期睡眠减少 ,睡眠结构紊乱。nCPAP治疗第 1夜及6个月后睡眠结构得到有效纠正 ,是OSAHS长期有效的治疗方法之一。     

Accuracy of positive airway pressure titration through telemonitoring of auto-adjusting positive airway pressure device connected to a pulse oximetry in patients with obstructive sleep apnea

Purpose

In COVID-19 era, all forms of access of patients to the sleep units should be reduced as much as possible when implementing telemedicine. In the field of obstructive sleep apnea (OSA) therapy with positive airway pressure (PAP) devices, telemedicine includes the use of built-in software (BIS) and storage of PAPs and remote-controlled data (BISrc data) that are processed and transmitted daily to sleep units. We compared two methods of evaluating the final residual severity of OSA patients in home PAP titration: BISrc data versus nocturnal portable multichannel monitoring (PM) data in PAP (reference method) and to verify whether the efficacy PAP therapy guided by BISrc data was clinically adequate.

Methods

We conducted a real-life prospective study in newly diagnosed patients with OSA. Patients used an auto-adjusting positive airway pressure (AirSense 10 ResMed) with a pulse oximeter that allows daily transfer of BISrc data (apnea hypopnea index [AHI] and SaO₂) and remote changes in ventilator setting. Once the PAP titration was completed, the pressure value or ranges were kept constant for 3 days and home PM was repeated.

Results

There were 41 patients with moderate to severe OSA who completed the study. When considering AHI only, the diagnostic accuracy of BISrc on the third day was equal to 97.5%; when considering AHI > 10/h, ODI > 10/h, and SaO₂ < 90%, the diagnostic accuracy slightly decreased to 90.2%.

Conclusion

In clinical practice, the two measurement methods are equivalent. The use of BISrc data for home titration would reduce the access to sleep units. We urge that widespread use of BISrc be promoted in the current practice of management of OSA.     

Long-term adherence to nasal continuous positive airway pressure therapy by hypertensive patients with preexisting sleep apnea

Background and objectiveAlthough positive screening for and treatment of obstructive sleep apnea (OSA) have been recommended for patients with cardiovascular problems, patient adherence to nasal continuous positive airway pressure (CPAP) therapy primarily for a cardiovascular concern is unknown. Therefore, this study aimed to determine the adherence to CPAP therapy by hypertensive patients with OSA after a screening test performed regardless of OSA-related symptoms.Subjects and methodsCPAP therapy was administered to 194 of the 1365 hypertensive patients who underwent the screening. The monthly dropout from CPAP therapy and the adequate use level (4 h every night, 70% days in a month) were assessed using the Kaplan–Meier analysis over a 3-year follow-up period.ResultsOf the patients, 106 (55%) refused or abandoned the therapy by the end of the follow-up period (adherence, 45%). An adequate use level was maintained by 76 patients (39%). Most of the patients’ background characteristics, including age, sex, Epworth sleepiness scale scores, and parameters obtained on polysomnography, were not related to adherence or adequate use level. The good-compliance level on the first visit after CPAP therapy introduction was most strongly related to adherence (95% CI, 0.05–0.32; p < 0.001) and adequate use level (95% CI, 0.06–0.33; p < 0.05). Fourth quartile of apnea hypopnea index value (greater than 67/h) was also related to adherence (95% CI, 0.21–0.98; p < 0.02) and adequate use level (95% CI, 0.19–0.88; p < 0.05).ConclusionsThe adherence and use level in this population may not be satisfactory but are comparable with those in previous sleep center reports treating symptomatic OSA patients. Thus, the present results would encourage hypertensive patients to undergo positive screening for OSA, regardless of OSA-related symptoms. However, an outcomes study with the same cohort is needed.     

经鼻持续气道内正压通气与咽手术治疗阻塞性睡眠呼吸暂停综合征对比观察

目的对比观察经鼻持续气道内正压通气（ＣＰＡＰ）与悬雍垂腭咽成形术（ＵＰＰＰ）治疗阻塞性睡眠呼吸暂停综合征（ＯＳＡＳ）的疗效及对睡眠呼吸参数的影响，评价二者在ＯＳＡＳ治疗中的地位。方法６０例ＯＳＡＳ患者，ＣＰＡＰ治疗组３６例，手术治疗组２４例。治疗前后作整夜多导睡眠图（ＰＳＧ）监测。结果两组呼吸紊乱指数减少，夜间低氧血症改善，ＣＰＡＰ组患者优于手术组（Ｐ＜０．０１）。有效率ＣＰＡＰ组为９７％，手术组为４６％（Ｐ＜０．０１），最长暂停时间ＣＰＡＰ组缩短，手术组改变不显著，１０例延长。结论ＣＰＡＰ疗效肯定，优于ＵＰＰＰ，适应证广，可作为ＯＳＡＳ首选治疗     

持续正压通气辅助治疗高血压并发睡眠呼吸暂停综合征的临床研究

目的探讨持续正压通气辅助治疗高血压并发睡眠呼吸暂停综合征（SAS）对血压的影响。方法41例高血压并发睡眠呼吸暂停综合征病人,随机分为常规组（21例）和持续正压通气治疗组（20例）均给予常规降压药物治疗4周,治疗在常规治疗基础上加用气道持续正压通气治疗,观察两组治疗前后24 h血压变化。结果治疗组治疗后24 h平均收缩压、舒张压进一步降低,夜间收缩压及舒张压则显著降低（P〈0.01）。结论高血压并发睡眠呼吸暂停综合征病人,在常规应用降压药物同时应用持续正压通气辅助治疗血压下降更理想。     

Long-term effects of nasal continuous positive airway pressure on vasodilatory endothelial function in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with a dysfunction of vascular endothelial cells. The aim of this study was to investigate long-term improvement of endothelial dysfunction in OSAS with nasal continuous positive airway pressure (nCPAP) treatment. We investigated endothelium-dependent and endothelium-independent vasodilatory function in patients with OSAS using the hand vein compliance technique. Dose–response curves to endothelium-dependent vasodilator bradykinin were obtained in 16 subjects with OSAS before and after 6 months of nCPAP therapy and in 12 control subjects without OSAS. Maximum dilation (Emax) to bradykinin, being impaired in all OSAS patients, was completely restored with nCPAP. Mean Emax to bradykinin rose from 54.9±18.5 to 108.2±28.7% with 164.4±90.0 nights of nCPAP therapy (p<0.0001; Emax healthy controls, 94.8±9.5%). At treatment follow-up, endothelium-dependent vasodilatory capacity was not significantly different in nCPAP-treated OSAS patients vs healthy controls. Mean vasodilation with endothelium independently acting nitroglycerin was not altered initially and did not change with nCPAP therapy indicating that nCPAP restored endothelial cell function and not unspecific, endothelium-independent factors. These results suggest that regular nocturnal nCPAP treatment leads to a sustained restoration of OSAS-induced impaired endothelium-dependent nitric oxide-mediated vasodilation, suggesting an improvement of systemic endothelial dysfunction in patients studied.     

CPAP治疗重度OSAHS的疗效观察

目的 观察持续气道正压通气(CPAP)治疗重度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的疗效、影响因素.方法 36例确诊为重度OSAHS的患者经CPAP治疗后,观察其治疗前后的呼吸暂停低通气指数(AHI)、夜间最低血氧饱和度(SaO2)及临床症状的变化.结果 治疗后AHI明显下降,夜间最低SaO2及临床症状明显改善.结论 CPAP是治疗重度OSAHS的有效方法.患者的依从性对重度OSAHS的治疗有决定性的意义.     

Association between sleep apnea severity and blood coagulability: treatment effects of nasal continuous positive airway pressure

A prothrombotic state may contribute to the elevated cardiovascular risk in patients with obstructive sleep apnea (OSA). We investigated the relationship between apnea severity and hemostasis factors and effect of continuous positive airway pressure (CPAP) treatment on hemostatic activity. We performed full overnight polysomnography in 44 OSA patients (mean age 47±10 years), yielding apnea–hypopnea index (AHI) and mean nighttime oxyhemoglobin saturation (SpO₂) as indices of apnea severity. For treatment, subjects were double-blind randomized to 2 weeks of either therapeutic CPAP (n=18), 3 l/min supplemental nocturnal oxygen (n=16) or placebo–CPAP (<1 cm H₂O) (n=10). Levels of von Willebrand factor antigen (VWF:Ag), soluble tissue factor (sTF), D-dimer, and plasminogen activator inhibitor (PAI)-1 antigen were measured in plasma pre- and posttreatment. Before treatment, PAI-1 was significantly correlated with AHI (r=0.47, p=0.001) and mean nighttime SpO₂ (r=−0.32, p=0.035), but these OSA measures were not significantly related with VWF:Ag, sTF, and D-dimer. AHI was a significant predictor of PAI-1 (R ²=0.219, standardized β=0.47, p=0.001), independent of mean nighttime SpO2, body mass index (BMI), and age. A weak time-by-treatment interaction for PAI-1 was observed (p=0.041), even after adjusting for age, BMI, pre-treatment AHI, and mean SpO₂ (p=0.046). Post hoc analyses suggested that only CPAP treatment was associated with a decrease in PAI-1 (p=0.039); there were no changes in VWF:Ag, sTF, and D-dimer associated with treatment with placebo–CPAP or with nocturnal oxygen. Apnea severity may be associated with impairment in the fibrinolytic capacity. To the extent that our sample size was limited, the observation that CPAP treatment led to a decrease in PAI-1 in OSA must be regarded as tentative.     

持续正压通气治疗阻塞性睡眠呼吸暂停低通气综合征伴高血压的护理

目的研究持续气道正压通气(CPAP)治疗阻塞性睡眠呼吸暂停低通气综合征(OSAHS)伴高血压的作用及护理。方法45例OSAHS伴高血压患者使用CPAP,每晚治疗8h。定时测量血压,并辅以积极的护理措施,观察患者治疗前后的血压变化。结果治疗后血压有所下降(P<0.05),下降时间为3～14d,平均(5±2.5)d。结论CPAP治疗OSAHS伴高血压是一种有效方法,护理有其特殊性和重要性。     

Autotitration positive airway pressure therapy in patients with obstructive sleep apnea who are intolerant of fixed continuous positive airway pressure

Compliance with continuous positive airway pressure (CPAP) therapy is one of the most difficult management problems for patients with obstructive sleep apnea (OSA). We postulated that autotitration positive airway pressure (APAP) may be effective in some patients who have an intolerance of fixed CPAP. The study was done to estimate how often patients who cannot tolerate fixed CPAP can tolerate APAP. We identified 25 patients seen in the Sleep Disorders Center who had been treated with fixed CPAP for OSA and were intolerant of CPAP therapy despite multiple efforts to improve tolerance. We substituted APAP therapy and measured subjective and objective compliance with treatment 1 month later. The primary end point was the number of patients who successfully tolerated the use of APAP at the end of 30 days, measured objectively by the device's compliance monitor. A positive outcome was defined as an average use of APAP that was greater than 3 h per night on more than 70% of possible nights. Of the 25 patients (mean age, 68 years; mean apnea-hypopnea index, 35), 11 were able to tolerate APAP therapy. The mean number of hours of use in these responders was 6.2; the mean percentage of nights of use among responders was 89%. Determinants of successful APAP use were an apnea-hypopnea index (AHI) less than 18, male sex, OSA related to rapid eye movement, and a high body mass index. APAP therapy may be an effective option in patients who do not tolerate fixed-CPAP therapy.     

Effects of continuous positive airway pressure treatment in obstructive sleep apnea patients with atrial fibrillation: A meta-analysis

Background:Obstructive sleep apnea (OSA) is correlated with atrial fibrillation (AF). Over the past decade, there has been an increasing interest in the relationship between OSA with continuous positive airway pressure (CPAP) and progression or recurrence of AF.Methods:This investigation was an analysis of studies searched in the Cochrane Library, PubMed, EMBASE, EBSCO, OVID, and Web of Science databases from inception to July 2020 to evaluate the recurrence or progression of AF in CPAP users, CPAP nonusers, and patients without OSA.Results:Nine studies with 14,812 patients were recruited. CPAP therapy reduced the risk of AF recurrence or progression by 63% in a random-effects model (24.8% vs 40.5%, risk ratio [RR] = 0.70, 95% confidence interval [CI] = 0.57–0.85, P = .035). Compared with non-OSA patients, AF recurrence or progression was much higher in CPAP nonusers (40.6% vs 21.1%, RR = 1.70, 95% CI = 1.19–2.43, P = .000). However, AF recurrence or progression in the CPAP group was similar to that in the non-OSA group (24.0% vs 21.1%, RR = 1.13, 95% CI = 0.87–1.47, P = .001). Begg correlation test and Egger regression test revealed no publication bias in this analysis.Conclusions:OSA is a salient factor in the progression or recurrence of AF. CPAP therapy for OSA may contribute to reduction of AF in patients for whom radiofrequency ablation or direct current cardioversion is not performed.Trial Registration:The protocol for this meta-analysis was registered on PROSPERO with a registration No. CRD42019135229.     

气道正压通气对阻塞性睡眠呼吸暂停低通气综合征合并高血压患者脉压的影响

目的探讨阻塞性睡眠呼吸暂停低通气综合征（OSAHS）合并高血压患者脉压的变化及经鼻持续气道正压通气（nCPAP）的影响。方法选择85例经多导睡眠图仪（PSG）诊断的OSAHS患者,同时随机选取15例中重度OSAHS患者进行nCPAP治疗,在PSG监测前后及期间每2小时测量其血压,计算出脉压、脉压变化幅度、平均收缩压及平均舒张压,并计算体重指数。结果41％OSAHS患者同时合并有高血压;OSAHS合并高血压组患者的呼吸紊乱指数、脉压及体重指数明显高于单纯OSAHS患者,其最低血氧饱和度以及平均血氧饱和度均低于单纯OSAHS患者;重度OSAHS患者的脉压、体重指数、平均收缩压及平均舒张压均明显大于轻、中度OSAHS患者,而轻、中OSAHS患者之间差异无显著性意义。nCPAP可提高OSAHS患者最低血氧饱和度,同时降低其呼吸紊乱指数、平均收缩压、平均舒张压及脉压。相关分析结果表明,呼吸紊乱指数与脉压（r=0．395,P〈0．01）、平均收缩压（r=0．403,P〈0．01）、平均舒张压（r=0．313,P〈0．01）呈正相关,与最低氧饱和度（r=-0．424,P〈0．01）呈负相关,与体重指数、平均氧饱和度无相关。结论脉压是OSAHS的严重程度及是否并发高血压心血管事件的预测因子;nCPAP能下调OSAHS患者脉压及血压,是缓解OSAHS病情进展的有效治疗措施。     

Influence of obstructive sleep apnea and treatment with continuous positive airway pressure on fractional flow reserve measurements for coronary lesion assessment

Obstructive sleep apnea (OSA) and sleep‐disordered breathing have been implicated in the progression of cardiovascular disease and with increased risk of coronary artery disease, congestive heart failure, and stroke. Fractional flow reserve (FFR) is used to evaluate the physiological significance of coronary artery stenosis, and this technique is largely thought to be independent of systemic hemodynamic changes. Herein, we describe a case of OSA and sleep‐disordered breathing cyclically altering FFR measurements from normal to abnormal in a patient with coronary artery disease. More specifically, we show that the abnormal FFR across a coronary lesion in a patient with sleep disordered apnea improves (to a normal threshold) with the initiation of continuous positive airway pressure (CPAP). This finding may have implications for the mechanisms of cardiac dysfunction in patients with OSA. © 2009 Wiley‐Liss, Inc.     

Higher effective oronasal versus nasal continuous positive airway pressure in obstructive sleep apnea: Effect of mandibular stabilization

BACKGROUND:

In some individuals with obstructive sleep apnea (OSA), oronasal continuous positive airway pressure (CPAP) leads to poorer OSA correction than nasal CPAP. The authors hypothesized that this results from posterior mandibular displacement caused by the oronasal mask.

OBJECTIVE:

To test this hypothesis using a mandibular advancement device (MAD) for mandibular stabilization.

METHODS:

Subjects whose OSA was not adequately corrected by oronasal CPAP at pressures for which nasal CPAP was effective were identified. These subjects underwent polysomnography (PSG) CPAP titration with each nasal and oronasal mask consecutively, with esophageal pressure and leak monitoring, to obtain the effective pressure (Peff) of CPAP for correcting obstructive events with each mask (maximum 20 cmH₂O). PSG titration was repeated using a MAD in the neutral position. Cephalometry was performed.

RESULTS:

Six subjects with mean (± SD) nasal Peff 10.4±3.0 cmH₂O were studied. Oronasal Peff was greater than nasal Peff in all subjects, with obstructive events persisting at 20 cmH₂O by oronasal mask in four cases. This was not due to excessive leak. With the MAD, oronasal Peff was reduced in three subjects, and Peff <20 cmH₂O could be obtained in two of the four subjects with Peff >20 cmH₂O by oronasal mask alone. Subjects’ cephalometric variables were similar to published norms.

CONCLUSION:

In subjects with OSA with higher oronasal than nasal Peff, this is partially explained by posterior mandibular displacement caused by the oronasal mask. Combination treatment with oronasal mask and MAD may be useful in some individuals if a nasal mask is not tolerated.     

持续气道正压治疗对阻塞性睡眠呼吸暂停患者夜间多尿症状的影响

目的研究持续气道正压（CPAP）治疗对阻塞性睡眠呼吸暂停综合征（OSAS）患者夜间多尿症状的影响。方法15例多导睡眠图（PSG）确诊的OSAS患者,记录CPAP治疗前后的夜尿次数、夜尿量、夜尿渗透压和夜尿钠排泄量,测定其中8例患者治疗前后夜间（23时、02时、05时）心钠素（ANP）水平。结果(1)CPAP治疗后OSAS患者夜尿次数明显减少（P<0.01）。(2)夜尿量由(0.078±0.017)L/h降至(0.052±0.011)L/h（P<0.01）。(3)CPAP治疗后OSAS患者夜尿渗透压由(381±96)mmol/L明显增高至(570±169)mmol/L（P<0.05）。(4)CPAP治疗后OSAS患者夜尿钠的排泄量由(1.16±0.35)mmol/h降至(0.63±0.13)mmol/h（P<0.01）。(5)8例患者CPAP治疗前后的夜间ANP平均水平分别为(146±14)ng/L和(106±10)ng/L,两者相比差异有显著性(P<0.01)。(6)8例测定ANP患者在CPAP治疗后ANP降低值与该患者夜尿量降低值、夜尿渗透压增高值、夜尿钠排泄量减少值均有显著的正相关,相关系数分别为0.82、0.84、0.81(P均<0.01)。结论CPAP治疗可明显减少OSAS患者夜尿次数和夜尿量,减少夜尿钠排泄量,增加夜尿渗透压,这些改变可能与ANP水平降低有关。     

Opioid-associated central sleep apnea: a case series

Introduction  Subjects on methadone maintenance for drug addiction have been reported to have central sleep apnea (CSA). However, there are few reports of disordered breathing in patients receiving opioids for chronic pain. Materials and methods  We report on six patients (ages 41–68, two females, body mass index 27–34, morphine equivalent doses 120–420 mg/day, Epworth Scales 7–21) referred to our sleep center receiving sustained release opioids for more than 6 months with excessive daytime sleepiness. CSA was defined as apnea–hypopnea index (AHI) more than 5 per hour with ≥50% central events. Bilevel (BLV) titration was done to determine settings and all patients were followed for at least 6 months on nocturnal BLV. AHI ranged 28.4–106 per hour. Time less than 90% O₂ saturation ranged 1.8 min to 6.4 h. Four of the patients were treated with chronic BLV ventilation with settings ranging 12–16 cm H₂O (inspiratory positive airway pressure)/4–8 cm H₂O (expiratory positive airway pressure) with backup rate of 12–16. Among the four patients who used BLV treatment for at least 6 months, Epworth scores improved (by 4, 12, 5, and 9, respectively). Conclusion  Treatment of opioid-associated CSA with BLV corrected nocturnal hypoxemia and reduced sleep fragmentation. Randomized controlled trials, with objective measures of daytime function, are recommended in opioid-induced CSA patients.