Negative Fluid Balance Associated With Lower Influenza Mortality in the ICU

Negative cumulative fluid balance in days 1 through 4 after intensive care unit (ICU) admission was associated with improved survival among critically ill patients with confirmed influenza, according to the results of a study published in PLoS One.

In this retrospective cohort study, patients with confirmed influenza infection admitted to ICUs at 8 medical centers in Taiwan were evaluated. Patients for whom complete fluid data in the first 3 days was lacking or who died within 3 days of intubation were excluded from the study. Mortality at 30 days was used to categorize patients as survivors (n=241) or non-survivors (n=55) and the daily and cumulative fluid balances were compared in both groups.

Compared with the survivor group, the non-survivor group had a more positive daily fluid balance on days 1 through 3: day 1 (1076 vs 593 mL; P =.069), day 2 (1280 vs 598; P =.001), and day 3 (613 vs 279 mL; P =.093). During the remaining days, the non-survivor group had a positive fluid balance, while the survivor group had a negative fluid balance: day 4 (704 vs -47 mL; P =.001), day 5 (93 vs -227; P =.128), day 6 (453 vs -452 mL; P =.003), and day 7 (468 vs -202 mL; P =.008).

Cumulative fluid balance on days 1 through 4 (P <.001), days 1 through 6 (P <.001), and days 1 through 7 (P <.001) were more positive in the non-survivor group compared with the survivor group.

In a Kaplan-Meier analysis, negative cumulative fluid balance between days 1 and 4 was associated with significantly reduced mortality risk (P =.003). When patients were stratified by shock status, negative cumulative fluid balance remained associated with a lower risk for mortality in the non-shock group (P =.008) but not in the shock group (P =.396).

The study investigators concluded that the results “showed an association between a negative cumulative day 1-4 fluid balance and a lower risk of 30-day mortality in our critically ill patients with influenza, particularly in those without shock. This study may provide information on the optimal fluid strategy in specific septic conditions such as complicated influenza.” They suggest that future studies might “identify prognostic and therapeutic molecular targets to guide and improve fluid management in patients with sepsis.”

Reference

Chao WC, Tseng CH, Chien YC, et al; TSIRC (Taiwan Severe Influenza Research Consortium). Association of day 4 cumulative fluid balance with mortality in critically ill patients with influenza: A multicenter retrospective cohort study in Taiwan. PLoS One. 2018;13:e0190952