Antonio Ana Carolina Peçanha, Fernandes Vivian Rodrigues, Azzolin Karina de Oliveira
Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Fellow nurse, Instituto de Cardiologia, Porto Alegre, Brazil.
J Crit Care Med (Targu Mures). 2021 Jan 29;7(1):46-53. doi: 10.2478/jccm-2020-0048. eCollection 2021 Jan.
Positive fluid status has been associated with a worse prognosis in intensive care unit (ICU) patients. Given the potential for errors in the calculation of fluid balance totals and the problem of accounting for indiscernible fluid losses, measurement of body weight change is an alternative non-invasive method commonly used for estimating body fluid status. The objective of the study is to compare the measurements of fluid balance and body weight changes over time and to assess their association with ICU mortality.
This prospective observational study was conducted in the 34-bed multidisciplinary ICU of a tertiary teaching hospital in southern Brazil. Adult patients were eligible if their expected length of stay was more than 48 hours, and if they were not receiving an oral diet. Clinical demographic data, daily and cumulative fluid balance with and without indiscernible water loss, and daily and total body weight changes were recorded. Agreement between daily fluid balance and body weight change, and between cumulative fluid balance and total body weight change were calculated.
Cumulative fluid balance and total body weight change differed significantly among survivors and non survivors respectively, +2.53L versus +5.6L (p= 0.012) and -3.05kg vs -1.1kg (p= 0.008). The average daily difference between measured fluid balance and body weight was +0.864 L/kg with a wide interval: -3.156 to +4.885 L/kg, which remained so even after adjustment for indiscernible losses (mean bias: +0.288; limits of agreement between -3.876 and +4.452 L/kg). Areas under ROC curve for cumulative fluid balance, cumulative fluid balance with indiscernible losses and total body weight change were, respectively, 0.65, 0.56 and 0.65 (p= 0.14).
The results indicated the absence of correspondence between fluid balance and body weight change, with a more significant discrepancy between cumulative fluid balance and total body weight change. Both fluid balance and body weight changes were significantly different among survivors and non-survivors, but neither measurement discriminated ICU mortality.
在重症监护病房（ICU）患者中，正液体平衡与较差的预后相关。鉴于液体平衡总量计算中存在误差的可能性以及难以察觉的液体丢失的核算问题，测量体重变化是一种常用的替代非侵入性方法，用于估计体液状态。本研究的目的是比较随时间变化的液体平衡测量值和体重变化，并评估它们与ICU死亡率的关联。
这项前瞻性观察性研究在巴西南部一家三级教学医院的34张床位的多学科ICU中进行。成年患者如果预期住院时间超过48小时且未接受口服饮食，则符合入选标准。记录临床人口统计学数据、有无不可察觉失水量时的每日和累积液体平衡以及每日和总体重变化。计算每日液体平衡与体重变化之间以及累积液体平衡与总体重变化之间的一致性。
幸存者和非幸存者的累积液体平衡和总体重变化分别存在显著差异，分别为+2.53L对+5.6L（p = 0.012）和-3.05kg对-1.1kg（p = 0.008）。测量的液体平衡与体重之间的平均每日差异为+0.864 L/kg，区间较宽：-3.156至+4.885 L/kg，即使在对不可察觉的液体丢失进行调整后仍然如此（平均偏差：+0.288；一致性界限在-3.876至+4.452 L/kg之间）。累积液体平衡、有不可察觉液体丢失时的累积液体平衡和总体重变化的ROC曲线下面积分别为0.65、0.56和0.65（p = 0.14）。
结果表明液体平衡与体重变化之间缺乏对应关系，累积液体平衡与总体重变化之间的差异更为显著。幸存者和非幸存者之间的液体平衡和体重变化均存在显著差异，但两种测量方法均无法区分ICU死亡率。
