ABSTRACT
OBJECTIVE: To investigate the effect of different interfaces on FiO_2 and CO_2 rebreathing(ViCO_2) during noninvasive positive pressure ventilation. METHODS: The Active Servo Lung respiratory simulation system was used to simulate a hypercapnia COPD patient received NPPV through injection of CO_2 gas from the place closest to the outlet of simulated lung to maintain end-tidal carbon dioxide partial pressure at 80 mmHg,and oxygen delivery during NPPV was simulated by means of injection of 5 L/min oxygen through the hole of interface. FiO_2 and ViCO_2 were integral calculated through the synchronous collect real-time pressure, flow rate, oxygen concentration and CO_2 concentration. The effect of different type and models of interfaces on FiO_2 and ViCO_2 were compared, and the bivariate correlation analysis was applied to investigate the correlation of FiO_2 and ViCO_2. RESULTS: The inner volume, leak volume and leak position of different interfaces were different. The FiO_2 of the oral-nasal mask and nasal mask were significantly different(P<0.05), which were(39.81±9.06)% and(43.91±6.33)%,respectively. The FiO_2 of the different models of interfaces was significantly different(P<0.05), the FiO_2 of the No.4 oral-nasal mask was the lowest(28.29±0.08)%, and the FiO_2 of the No. 10 oral-nasal mask was the highest(53.83±0.63)%. The ViCO_2 of the oral-nasal mask and nasal mask wasn't significantly different(P=0.19), which was(15.26±1.27)mL and(14.79±2.21)mL, respectively. The ViCO_2 of the different models of interfaces was significantly different(P<0.05), the FiO_2 of the No.8 nasal mask was the lowest(12.48±0.29%), and the ViCO_2 of the No. 10 nasal mask was the highest(18.38±0.31)%. There was a significant correlation between FiO_2 and ViCO_2(r=0.41, P<0.05), and the general linear equation was Y=14.51+1.82 X(R~2=0.168). CONCLUSION: Different interfaces have significant effects on FiO_2 and ViCO_2 during NPPV,and FiO_2 and ViCO_2 are positively correlated.
ABSTRACT
<p><b>BACKGROUND</b>More and more percutaneous coronary intervention were done from radial artery approach. But the great limitation of radial artery approach and main failure cause of transradial coronary intervention is smaller size and more variations of a radial artery approach. The aim of the study is to explore the features and variations of a radial artery approach in southern Chinese populations and their clinical significance in percutaneous coronary intervention.</p><p><b>METHODS</b>A total of 1400 patients who underwent scheduled first time transradial coronary angiography between July 2007 and September 2010 were enrolled. Radial arteriography was performed in all patients to detect the anatomical variations of this vessel. All patients' radial and ulnar artery inner diameters were measured using a computer assisted quantification method. A detailed patient history was recorded. Multivariate Logistic regression analysis was performed to evaluate the predictive value of variables (including age, gender, ethnicity, height, weight, body mass index, smoking, diabetes, hypertension and dyslipidemia) in arterial tortuosities and variations of this vessel.</p><p><b>RESULTS</b>In southern Chinese populations, there were no significant differences in the diameters of the forearm arteries: the mean radial artery inner diameter was (3.04 ± 0.43) mm in ethnic Han Chinese and (3.05 ± 0.42) mm in ethnic Zhuang Chinese, P > 0.05), the mean ulnar artery inner diameter was (3.03 ± 0.38) mm in Han Chinese and (3.05 ± 0.36) mm in Zhuang Chinese, P > 0.05). It was estimated that the inner diameter of the radial artery was not smaller than a 6F Cordis sheath in 86.1% of male patients and in 57.0% of female patients, and not smaller than a 7F Cordis sheath in 59.3% of male patients and 24.9% of female patients. The factors found to positively affect the size of the radial artery were sex (bj = 0.309, P < 0.01), weight (bj = 0.103, P < 0.01), and diabetes mellitus (bj = -0.088, P < 0.01) was found to negatively affect radial artery size. Arterial tortuosities occurred in 12.1% of patients and arterial variations in 4.1%. The incidence of tortuosities and variations included radial artery tortuosity (3.6%), high origin of radial artery (1.7%), radial artery loop (0.6%), double radial artery (0.1%), brachial artery tortuosity (0.4%), double brachial artery (0.1%), subclavian artery tortuosity (5.4%), small subclavian artery (0.4%), right retro-esophageal subclavian artery (0.6%), brachiocephalic trunk tortuosity (2.8%), small brachiocephalic artery (0.1%), and brachiocephalic artery anomaly (0.4%). For people in Guangxi province, tortuosities of the subclavian artery and radial artery are the most common among the vascular tortuosities of the radial artery approach. The overall rate of transradial procedural success was 96.1%. Procedural failure was more common in patients with anomalous radial artery approach than in patients with normal radial artery approach (22.8% vs. 1.8%, P = 0.000). According to multivariate Logistic regression analysis, age (OR = 2.695, 95%CI 2.232 - 3.253, P = 0.000), female gender (OR = 5.127, 95%CI 3.000 - 8.762, P = 0.000), height (OR = 0.612, 95%CI 0.465 - 0.807, P = 0.000), body mass index (OR = 2.377, 95%CI 1.834 - 3.082, P = 0.000), hypertension (OR = 1.668, 95%CI 1.132 - 2.458, P = 0.010), hyperlipidemia (OR = 1.273, 95%CI 1.425 - 2.049, P = 0.034) and smoking (OR = 5.750, 95%CI 3.636 - 9.093, P = 0.000), were independently associated with arterial tortuosities of the radial artery approach. Female gender was independently associated with arterial variations of the radial artery approach (OR = 3.613, 95%CI 3.208 - 7.826, P = 0.000).</p><p><b>CONCLUSIONS</b>The diameters of the radial and ulnar arteries between the Han people and the Zhuang people in southern Chinese populations are similar. In a transradial operation, the most southern Chinese populations, the use of a 6F sheath and guiding catheter is safe, and using a 7F sheath and guiding catheter is feasible in some selected patients. Radial arterial tortuosities and variations in southern Chinese populations are relatively common and are a significant cause of the failure of transradial coronary procedure. Old age, female gender, short stature, high body mass index, hypertension, hyperlipidemia and smoking, were independently associated with an increased risk of arterial tortuosity. In addition, female gender was an independent predictor of arterial variations.</p>