The value of drug-induced sleep computed tomography in diagnosis of obstructive sleep apnea syndrome: a pilot study

Abstract

Background: Obstructive sleep apnea syndrome (OSAS) is a public health problem that affects a large amount of people. Surgery sometimes is considered a better treatment modality that does not require the use of a device such as CPAP.

Objectives: To explore the value of anesthetic-induced sleep computed tomography (DI-SCT) in the diagnosis of OSAS.

Materials and methods: A total of 124 patients with OSAS aged between 18 and 65 years old were enrolled in this study. The upper airway was scanned by computed tomography (CT) while they were wake and went sleep. Sleep was induced by dexmedetomidine under electrocardiograph and oxyhemoglobin saturation monitoring. Parameters relevant to OSAS were then collected and counted.

Results: CT scanning revealed that 119 occurred stenosis in oropharynx, in which 5 cases were accompanied with stenosis or occlusion at retroglossal area. About 38 (30.67%) cases existed deviation of nasal septum with retropalatal problems. About 61.33% of patients had multi-level obstructions and the most common obstructive site was oropharynx (90.67%).

Conclusions and significance: DI-SCT is a safe and non-invasive modality for diagnosing the obstructive sites in OSAS patients.     

A New Approach to Diagnosing of Importance Degree of Obstructive Sleep Apnea Syndrome: Pairwise AIRS and Fuzzy-AIRS Classifiers

Artificial Immune Recognition System (AIRS) classifier algorithm is robust and effective in medical dataset classification applications such as breast cancer, heart disease, diabetes diagnosis etc. In our previous work, we have proposed a new resource allocation mechanism called fuzzy resource allocation in AIRS algorithm both to improve the classification accuracy and to decrease the computation time in classification process. Here, AIRS and Fuzzy-AIRS classifier algorithms and one against all approach have been combined to increase the classification accuracy of obstructive sleep apnea syndrome (OSAS) that is an important disease that influences both the right and the left cardiac ventricle. The OSAS dataset consists of four classes including of normal (25 subjects), mild OSAS (AHI (Apnea and Hypoapnea Index) =5-15 and 14 subjects), moderate OSAS (AHI < 15-30 and 18 subjects), and serious OSAS (AHI > 30 and 26 subjects). In the extracting of features that is characterized the OSAS disease, the clinical features obtained from Polysomnography used diagnostic tool for obstructive sleep apnea in patients clinically suspected of suffering from this disease have been used. The used clinical features are Arousals Index (ARI), Apnea and Hypoapnea Index (AHI), SaO2 minimum value in stage of REM, and Percent Sleep Time (PST) in stage of SaO2 intervals bigger than 89%. Even though AIRS and Fuzzy-AIRS classifiers have been used in the classifying multi-class problems, theirs classification performances are low in the case of multi-class classification problems. Therefore, we have used two classes in AIRS and Fuzzy-AIRS classifiers by means of one against all approach instead of four classes comprising the healthy subjects, mild OSAS, moderate OSAS, and serious OSAS. We have applied the AIRS, Fuzzy-AIRS, AIRS with one against all approach (Pairwise AIRS), and Fuzzy-AIRS with one against all approach (Pairwise Fuzzy-AIRS) to OSAS dataset. The obtained classification accuracies are 63.41%, 63.41%, 87.19%, and 84.14% using the above methods for 200 resources, respectively. These results show that the best method for diagnosis of OSAS is the combination of AIRS and one against all approach (Pairwise AIRS).     

高海拔地区阻塞性睡眠呼吸暂停综合征患者手术前后血压的变化

目的:探讨高海拔地区阻塞性睡眠呼吸暂停综合征患者手术前后血压的变化。方法:通过对16例OSAS伴高血压病人行改良UPPP手术,测定手术前及术后一周、术后2个月患者收缩压和舒张压的变化。结果:16例SOAS合并高血压患者手术后两次测定血压,血压逐渐下降,手术后2个月收缩压和舒张压与治疗前比较差别有显著性,P<0.01。结论:OSAS与高血压有关,在高海拔缺氧环境地区缺氧更为明显,通过手术治疗,减少了上呼吸道阻力,从而使缺氧症状明显改善,对高血压有一定治疗意义。     

Predictors of decreased spontaneous baroreflex sensitivity in obstructive sleep apnea syndrome

BACKGROUND: The impact of obstructive sleep apnea syndrome (OSAS) on the arterial baroreflex, and its significance, is still under debate. We investigated the baroreflex sensitivity (BRS) during sleep in well-selected OSAS patient and control subject cohorts METHODS: We performed a prospective study of 10 non-OSAS subjects, 14 subjects with mild-to-moderate OSAS, and 14 male subjects with severe OSAS subjects. Groups were matched for age, body mass index, and other relevant variables. Subjects had no other disease and were not receiving regular medication. BP was monitored beat-by-beat (Portapres; Finapres Medical Systems; Amsterdam, the Netherlands) at night during polysomnography. Spontaneous BRS was assessed by the sequence technique. Heart-rate correction was also applied to calculate BRS at a heart rate (HR) of 60 beats/min (BRS-60) to account for intersubject variability in baseline HR. Eight suitable patients were treated with continuous positive airway pressure (CPAP), and BRS measurements were repeated 6 weeks later. RESULTS: BRS and BRS-60 were significantly lower in patients with severe OSAS than in patients with mild-to-moderate OSAS and in non-OSAS subjects, and a separate sleep-stage analysis revealed this difference to be evident in stage 2 non-rapid eye movement sleep and during nocturnal wakefulness. There was no difference in BRS and BRS-60 between non-OSAS subjects and patients with mild-to-moderate OSAS. In multivariate analysis, the desaturation index was the only independent predictor of depressed BRS. CPAP therapy significantly improved the BRS measures. CONCLUSION: Patients with severe OSAS demonstrate depressed BRS during sleep, which may contribute to the cardiovascular pathophysiology in OSAS patients.     

OSAS患者右心室变化及CPAP对右心室影响的研究

目的：了解睡眠呼吸暂停综合征（OSAS）患右心室病理生理改变，及持续气道正压通气（CPAP）治疗对患右心室的影响。方法：正常人96人，OSAS患96例，并随机分成治疗组与对照组，一组OSAS患经CPAP治疗2年，另一组OSAS未给予相同治疗，利用彩色多普勒超声系统测量正常人组实验开始时及96例OSAS患开始及两年后右室前壁厚度（ RVT）肺动脉收缩压（PASP）、肺动脉舒张压（PADP）、右室舒张期内径（DDRV）、右室收缩期内径（SDRV）、右室射血分数（REF）、肺动脉流速（PAF）。比较正常人组与96例OSAS患各指标差异显性。两组间所有指标差异均有统计学意义。结论：OSAS患肺循环有明显病理性改变，表现为右心室变厚，右心室内径增大、射血分数降低、肺动脉压升高等系列改变。长期CPAP治疗后，这种病理生理改变较对照组停止，提示CPAP对OSAS患的心脏结构及功能有保护作用。     

持续气道内正压通气治疗阻塞性睡眠呼吸暂停综合征前后血清瘦素及胃饥饿素的变化

目的为观察阻塞性睡眠呼吸暂停综合征(OSAS)患者在持续气道内正压通气(CPAP)治疗前后血清瘦素和胃饥饿素的变化。方法选择沈阳医学院附属中心医院2004年4月至2005年9月收治的20例OSAS患者。诊断符合中华医学会呼吸学会睡眠学组制定的标准。CPAP治疗前及治疗1周后、6个月后进行空腹血糖(FBG)、真胰岛素(TI)、瘦素和胃饥饿素的测定。结果CPAP治疗1周后,血浆胃饥饿素,瘦素有所下降,但FBG和TI无明显变化。CPAP治疗6个月后,胃饥饿素及瘦素水平明显下降。FBG和TI也有所下降。CPAP治疗有效地改善睡眠呼吸紊乱及低氧状态,生活质量明显提高。结论血清瘦素、胃饥饿素水平通过长期CPAP治疗可明显下降。CPAP长期治疗可以改善OSAS的糖代谢和胰岛素抵抗。因此,OSAS可能是导致胃饥饿素和瘦素代谢紊乱引起体重增加,导致肥胖原因之一。     

电刺激老龄大鼠缰核引起的呼吸效应

目的探讨电刺激大鼠缰核(Hb)对呼吸运动的影响及阻塞性睡眠呼吸暂停综合征(OSAS)的可能机制.方法电刺激大鼠Hb相应部位,同一刺激位点调整刺激参数,分别给予70 μA或90 μA电流强度,对照组给予同样电流刺激,记录刺激前后呼吸频率、胸廓运动幅度的数值.结果电刺激Hb可以引起呼吸频率加快、呼吸幅度加大(P＜0.05),同一刺激位点刺激强度增加可引起呼吸频率增加更明显(P＜0.05),呼吸幅度变化不大(P＜0.05).电刺激内侧缰核(MHb)内侧部出现呼吸明显减慢甚至呼吸暂停,同时呼吸幅度变浅(P＜0.05).电刺激MHb外侧部(L:0.3)和外侧缰核(L:0.5)均出现刺激过程中呼吸加快,但电刺激时胸廓运动幅度可有幅度变大或变小两种改变.结论 Hb可能参与呼吸运动的调节及OSAS的发生.     

Impaired objective daytime vigilance in obesity-hypoventilation syndrome: impact of noninvasive ventilation

BACKGROUND: Obesity-hypoventilation syndrome (OHS) is efficiently treated by noninvasive ventilation (NIV). Sleep respiratory disturbances, reduced ventilatory drive, and excessive daytime sleepiness (EDS) are commonly reported, but their relationships remain unclear. OBJECTIVES: To characterize sleep breathing disorders encountered in patients with OHS, to compare low and normal CO(2) responders in terms of sleep abnormalities, subjective and objective measures of EDS, and to measure the changes induced by NIV on these parameters. METHODS: At baseline and after 5 nights of NIV, 15 consecutive patients (mean [+/- SD] age, 55 +/- 9 years; mean body mass index, 38.7 +/- 6.1 kg/m(2); Paco(2), 47.3 +/- 2.3 mm Hg) prospectively underwent polysomnography, CO(2) ventilatory response testing, Epworth sleepiness scale scoring, and the Oxford Sleep Resistance (OSLER) test, which is an objective vigilance test. RESULTS: OHS patients exhibited obstructive sleep apnea syndrome (mean apnea-hypopnea index, 62 +/- 32 events per hour) and rapid eye movement (REM) sleep hypoventilation (mean REM sleep time, 35 +/- 33%). Baseline CO(2) sensitivity was significantly related to the proportion of hypoventilation during REM sleep (r = 0.54; p = 0.037). Six patients showed abnormal sleep latencies during the OSLER test (71% of the low CO(2) responders vs 14% of the normal CO(2) responders). Low CO(2) responders exhibited significantly shorter sleep latencies during the OSLER test (23 +/- 14 vs 37 +/- 8 min, respectively; p = 0.05). Using NIV, diurnal blood gas levels were improved and REM sleep hypoventilation were suppressed. Objective sleepiness was improved in low CO(2) responders (p = 0.04). CONCLUSION: In OHS patients, the lower the daytime CO(2) response, the higher the proportion of REM sleep hypoventilation and daytime sleepiness. Short-term therapy with NIV improves all of these parameters.     

阻塞性睡眠呼吸暂停综合征患者不同体位下上气道变化的临床观察

目的:对阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)患者不同体位下上气道的变化做了观察比较,初步探讨了仰卧位时上气道软组织及骨组织位置及结构的变化,为OSAS的诊治提供有关依据.方法:对10例经PSG确诊的OSAS患者分别拍摄常规坐位头影测量侧位片及仰卧位头颅侧位片.测量两种体位下腭后气道前后径、软腭下垂角度、最小矢状咽径、下颌平面角及舌骨至咽后壁水平距离等.结果:两种体位比较,仰卧位时最小矢状咽径、悬雍垂顶点至咽后壁的水平距离及软腭中点至咽后壁的水平距离均小于坐位时;软腭下垂角度及下颌平面角大于坐位时;∠SNB小于坐位时;舌骨无明显前移或后退.结论:OSAS患者仰卧位时腭后气道的前后径及最小矢状咽径更趋狭小,软腭向咽后壁方向移位,下颌骨以颞下颌关节为中心呈向下向后方旋转运动,从而使上气道在腭咽气道、舌咽气道及下咽气道多个水平趋于狭小.OSAS患者多在卧位时发病,在OSAS患者术前评估时,仰卧位X线头颅侧位片可以更客观的反映患者上气道解剖情况,为OSAS患者的治疗提供更为可靠的依据.