[Effect of HCO3- level on the accuracy of NoSAS screening for obstructive sleep apnea hypopnea syndrome].

Objective: To evaluate the effect of arterial blood HCO3- level on the accuracy of NoSAS questionnaire screening for obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: The hospitalized patients with suspected OSAHS were recruited from March 2016 to December 2017 in the First Affiliated Hospital of Guangzhou Medical University. NoSAS scores, blood gas analysis and polysomnography (PSG) were performed in these patients. Patients were divided into non OSAHS group and mild, moderate and severe OSAHS group according to the PSG results. According to the NoSAS questionnaire score, the patients were divided into OSAHS high-risk group and low risk group. The correlation between arterial blood HCO3- level and apnea hypopnea index (AHI) was analyzed. The receiver operating characteristic (ROC) curve was plotted to analyze the accuracy of HCO3- prediction OSAHS. Predictive parameters(sensitivity, specificity, positive and negative predictive values)for NoSAS scores and HCO3- level were calculated. Results: A total of 243 patients with suspected OSAHS were included, including 186 males (76.5%), 57 females (23.5%), age (49±13) years, body mass index (BMI) (26.9±4.4) kg/m2, and neck circumference (38.6±4.5) cm. The HCO3- level was positively correlated with AHI (r=0.206, P=0.001). The proportion of patients with HCO3- level ≥26 mmol/L in non-OSAHS group was lower than that in OSAHS group (13.0% vs 34.5%, P=0.004); the proportion of patients with HCO3- level ≥26 mmol/L in severe OSAHS group was higher than that in mild OSAHS group (37.7% vs 15.0%, P=0.008), and there was no difference in the ratio of patients with severe OSAHS and moderate OSAHS (37.7% vs 35.3%, P=0.767). The specificity of OSAHS predicted by HCO3- level 25 and 26 mmol/L was 69.6% and 87.0%, respectively. With the NoSAS score of 8 or 7 as cutoffs for analysis, the sensitivity for OSAHS was 61.9% and 79.2%, the specificity for OSAHS was 57.4% and 40.4%, respectively. With the addition of HCO3- level ≥ 26 mmol/L to the NoSAS score ≥ 7, the specificity for OSAHS improved to 93.6%, while the sensitivity decreased to 27.4%. Conclusion: Combined with the arterial blood HCO3- level, the specificity of the NoSAS questionnaire increases and the sensitivity decreases.

[Comparison of the NoSAS score with four different questionnaires as screening tools for obstructive sleep apnea-hypopnea syndrome].

Objective: To evaluate the clinical utility of the NoSAS score in the screening of patients with obstructive sleep apnea-hypopnea syndrome(OSAHS), and to compare the performance of the NoSAS score with other tools including Epworth Sleepiness Scale(ESS), STOP, STOP-Bang(SBQ) and Berlin questionnaires. Methods: A total of 444 consecutive patients(328 males and 116 females) with suspected OSAHS who underwent an overnight polysomnography(PSG) were recruited into this study. Five questionnaires including the NoSAS score, ESS, STOP, SBQ and Berlin were completed. Based on the severity of OSAHS which was determined by apnea-hypopnea index(AHI), the patients were classified into 4 groups: normal(<5 events/h), mild(5-15 events/h), moderate(15-30 events/h) and, severe (≥30 events/h) OSA.Sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics curve of 5 questionnaires were calculated. Results: With AHI≥5 events/h as the standard diagnosis of OSAHS, the NoSAS score and SBQ questionnaire showed a moderate performance, with the NoSAS score having the largest area under the ROC curve(0.753, P<0.001), followed by the SBQ questionnaire (0.727, P<0.001). The performance of the ESS, Berlin, and the STOP questionnaire was not high. Using mild moderate-severe(≥5 events/h), moderate-severe(≥15 events/h), and severe(≥30 events/h)OSAHS as cutoffs, NoSAS had the highest specificity and positive predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the sensitivity and negative predictive values were (51.5% and 36.9%, 56.5% and 59.1%, 66.3% and 74.2%) .SBQ had the highest sensitivity and the negative predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the specific and positive predictive values were (45.7% and 81.0%, 39.1% and 61.9%, 34.8% and 44.4%). The NoSAS score ≥ 7 had higher sensitivity and negative predictive value(75.0% and 47.1%, 78.1% and 66.5%, 82.7% and 81.9%)than the NoSAS socre ≥ 8. With AHI≥5 events/h as the standard diagnosis of OSAHS, the NoSAS score and the SBQ questionnaire had a higher accuracy than the other 3 questionnaires as screening questionnaires for diagnosing OSAHS, and the value of DOR were 4.298 and 3.758 respectively. Conclusions: The NoSAS score and the SBQ questionnaire have a moderate performance in diagnosing OSAHS. The NoSAS score is a new screening tool, and it is similar to the SBQ questionnaire, being also simple and effective. While the SBQ questionnaire is more widely used, it is necessary to further evaluate the diagnostic value of NoSAS score.

[Correlation between peripheral venous oxygen saturation and hemodynamic parameters in patients with pulmonary hypertension].

Objective: To investigate the correlation of peripheral venous oxygen saturation (SpvO(2)) with mixed venous oxygen saturation (SvO(2)), pulmonary vascular resistance (PVR) and cardiac index (CI) in patients with pulmonary hypertension (PH), in order to predict these parameters using SpvO(2) and assess the prognosis of patients. Methods: Hospitalized patients diagnosed with PH by right heart catheterization in the Guangzhou Institute of Respiratory Diseases from July 2015 to October 2016 were retrospectively analyzed. Parameters during the right heart catheterization, including SvO(2,)SpvO(2,)cardiac output (CO) and mean pulmonary arterial pressure (mPAP) were recorded, while CI, PVR and other parameters were indirectly calculated. The correlation between SpvO(2) and SvO(2,)CO, CI, mPAP, PVR and other parameters were respectively analyzed and compared between groups. Results: A total of 77 PH patients were selected, which comprised of 39 males and 38 females. The results revealed that SpvO(2) was correlated positively with SvO(2,)CI and PaO(2) (P<0.05), but negatively with PVR, total pulmonary resistance (TPR), systemic vascular resistance, right atrial diameter and right ventricular diameter (P<0.05). In the group with SpvO(2) <65%, the dilation of the right atrium and right ventricle was more significant, the WHO heart function grade was worse, CI, systemic systolic pressure and mean systemic pressure were lower, and PVR and TPR were higher, as compared to those in the group with SpvO(2) ≥65%. (P<0.05). Conclusions: There was good consistency between SpvO(2) and SvO(2). Furthermore, SpvO(2) could indirectly reflect the CI, PVR and changes in right heart structure of PH patients, providing reference for the clinical prediction of CI and PVR, as well as the prognosis of PH patients, through the use of SpvO(2). Low SpvO(2) indicated a severe condition and poor prognosis.

[Severe obstructive sleep apnea-hypopnea syndrome with dilated cardiomyopathy leading to pulmonary hypertension: case report and literature review].

Objective: To study the relationship between dilated cardiomyopathy and obstructive sleep apnea-hypopnea syndrome (OSAHS) and to evaluate the curative effects of continuous positive airway pressure (CPAP) in OSAHS complicated with dilated cardiomyopathy. Methods: We reported one case with the symptom of exertional dyspnea for 1 year and aggravating for 1 month. The patient finally was diagnosed with severe OSAHS complicated with dilated cardiomyopathy leading to pulmonary hypertension. A systematic literature review was performed for similar published cases in Pubmed, Wanfang and CNKI database, using the keywords (obstructive sleep apnea) OR(OSA) OR(OSAHS) AND(dilated cardiomyopathy OR DCM)from January 1990 to May 2016. Results: Our patient had no significant improvement after receiving initial treatments, including reducing cardiac preload, improving myocardial metabolism, increasing myocardial contractility, and anticoagulants. After the patient was diagnosed as having severe OSAHS by polysomnography(PSG) and treated with CPAP, his symptoms improved remarkably. The enlarged heart became smaller and the patient had no repeated dyspnea at follow-up examination. By literature review, we found 4 English original articles and 6 Chinese articles (1 review article, 1 expert note, 1 original article and 3 case reports) on OSAHS complicated by DCM.Four Chinese and 1 English articles reported that the symptoms and parameters of OSAHS with DCM was improved remarkably after treatment with CPAP. Conclusion: For patients with dilated cardiomyopathy which fails to conventional therapy, especially those accompanied by obesity, snoring, daytime sleepiness, morning dry mouth and other related symptoms, PSG should be carried out. Early CPAP therapy could improve symptoms and prognosis of OSAHS associated with DCM.