Stewart analysis of apparently normal acid-base state in the critically ill

详细信息    查看全文

• 作者：Miriam Moviat ; Mark van den Boogaard ; Femke Intven ; Peter van der Voort ; Hans van der Hoeven ; Peter Pickkers
• 关键词：BE ; base excess ; SIDa ; apparent strong ion difference ; SIDe ; effective strong ion difference ; SIG ; strong ion gap ; APACHE-II ; Acute Physiology and Chronic Health Evaluation II ; SOFA ; Sequential Organ Failure Assessment ; SD ; standard deviation ; IQR ; interquartile range ; RIFLE ; Risk ; Injury ; Failure ; Loss ; and End-stage Kidney disease ; CVVH(D) ; continuous venovenous hemo(dia)filtration
• 刊名：Journal of Critical Care
• 出版年：December, 2013
• 年：2013
• 卷：28
• 期：6
• 页码：1048-1054
• 全文大小：502 K

文摘

Purpose

This study aimed to describe Stewart parameters in critically ill patients with an apparently normal acid-base state and to determine the incidence of mixed metabolic acid-base disorders in these patients.

Materials and Methods

We conducted a prospective, observational multicenter study of 312 consecutive Dutch intensive care unit patients with normal pH (7.35 鈮?pH 鈮?7.45) on days 3 to 5. Apparent (SIDa) and effective strong ion difference (SIDe) and strong ion gap (SIG) were calculated from 3 consecutive arterial blood samples. Multivariate linear regression analysis was performed to analyze factors potentially associated with levels of SIDa and SIG.

Results

A total of 137 patients (44%) were identified with an apparently normal acid-base state (normal pH and 鈭?#xA0;2 < base excess < 2 and 35 < PaCO₂ < 45 mm Hg). In this group, SIDa values were 36.6 卤 3.6 mEq/L, resulting from hyperchloremia (109 卤 4.6 mEq/L, sodium-chloride difference 30.0 卤 3.6 mEq/L); SIDe values were 33.5 卤 2.3 mEq/L, resulting from hypoalbuminemia (24.0 卤 6.2 g/L); and SIG values were 3.1 卤 3.1 mEq/L. During admission, base excess increased secondary to a decrease in SIG levels and, subsequently, an increase in SIDa levels. Levels of SIDa were associated with positive cation load, chloride load, and admission SIDa (multivariate r² = 0.40, P < .001). Levels of SIG were associated with kidney function, sepsis, and SIG levels at intensive care unit admission (multivariate r² = 0.28, P < .001).

Conclusions

Intensive care unit patients with an apparently normal acid-base state have an underlying mixed metabolic acid-base disorder characterized by acidifying effects of a low SIDa (caused by hyperchloremia) and high SIG combined with the alkalinizing effect of hypoalbuminemia.