- 學位論文
滲透壓在不同方法學之滲透壓間隙及干擾之探討
Osmolal Gap and Interference of Different Methods for Osmolality
摘要
測定血液滲透壓可用以評估患者體內電解質與水份之間的平衡狀態，有助於辨別患者發生體液過多或是脫水現象，對於中毒及昏迷患者是非常重要的鑑別診斷項目。滲透壓間隙(osmolal gap)為血液的實際測定值與計算值之間的差異，而目前已知會影響滲透壓間隙常見的有乙醇，丙酮，乙醯水楊酸等這些非離子物質。本研究利用冰點下降及蒸氣式測定滲透壓的方法，探討血糖及尿素氮對滲透壓間隙的可能影響。研究結果顯示，以AAB滲透壓總誤差允許範圍為10%的規範下，冰點測定法差距超過10%的件數有116件，蒸氣式測定法則有9件，分別佔4.84%與3.81%。因此，冰點測定法與蒸氣式測定法的準確度不具顯著差異。冰點下降法的滲透壓間隙與血糖之間呈現中度相關且具顯著統計意義(r= 0.385; p < 0.001)，蒸氣式測定法的滲透壓間隙受血糖的影響較小，呈現低度相關但仍具顯著統計意義(r= 0.254; p <0.001)。將血糖分為正常血糖、高血糖與極高血糖三個群組，冰點下降法在高血糖呈現低度相關(r=0.191; p<0.001)，在極高血糖呈現中度相關(r=0.37; p<0.001)。目前臨床實驗室使用冰點下降法測量滲透壓的比例約佔90%，由於冰點下降法中血糖越高對於滲透壓間隙的影響程度也越高，建議臨床上利用冰點測定法檢測滲透壓間隙應特別注意血糖濃度。
並列摘要
Measurement of blood osmotic pressure can be used to assess the balance of electrolytes and water contents in human body. It can benefit the identification of fluid overloading or dehydration, which is a very important diagnostic parameter for those patients with poisoning and coma. Osmolal gap is the difference between the actual measured values and the calculated values of blood difference. Currently, the osmolal gap can be affected by ethanol, acetone, and acetyl salicylic acid. The aim of this study was to explore the possible influence resulted from blood glucose and blood urea nitrogen using freezing point depression method and vapor pressure method. The results indicate that, according to the AAB regulation for osmotic pressure within the total error allowable (TEa) range of 10%, 116 subjects (4.84%) and 9 subjects (3.81%) are above 10% TEa by the freezing point method and the vapor pressure method, respectively. Thus, no significant difference was found for the accuracy between the freezing point method and vapor pressure method. A significant positive correlation between glucose and osmolal gap measured by freezing point depression method was observed ( r = 0.385; p < 0.001). To a lesser extent, blood glucose affected the osmolal gap measured by vapor pressure method, which exhibited low correlation but remained statistically significant (r = 0.254; p < 0.001). The correlation coefficient(r) obtained from the high blood sugar group by the freezing point depression method showed low correlation (r = 0.191; p < 0.001), while the extremely high blood sugar group showed moderate correlation ( r = 0.37; p < 0.001). In clinical laboratory the freezing point depression method is the predominant methodology used to measure osmotic pressure. We suggest that blood glucose levels should be monitored with caution because higher blood glucose would produce higher impact on osmolal gap when using the freezing point depression method to measure osmolal gap.