Importance: Slower intravenous fluid infusion rates could reduce the formation of tissue edema and organ dysfunction in critically ill patients; however, there are no data to support different infusion rates during fluid challenges for important outcomes such as mortality.
Objective: To determine the effect of a slower infusion rate vs control infusion rate on 90-day survival in patients in the intensive care unit (ICU).
Design, Setting, and Participants: Unblinded randomized factorial clinical trial in 75 ICUs in Brazil, involving 11?052 patients requiring at least 1 fluid challenge and with 1 risk factor for worse outcomes were randomized from May 29, 2017, to March 2, 2020. Follow-up was concluded on October 29, 2020. Patients were randomized to 2 different infusion rates (reported in this article) and 2 different fluid types (balanced fluids or saline, reported separately).
Interventions: Patients were randomized to receive fluid challenges at 2 different infusion rates; 5538 to the slower rate (333 mL/h) and 5514 to the control group (999 mL/h). Patients were also randomized to receive balanced solution or 0.9% saline using a factorial design.
Main Outcomes and Measures: The primary end point was 90-day survival.
Results: Of all randomized patients, 10?520 (95.2%) were analyzed (mean age, 61.1 years [SD, 17.0 years]; 44.2% were women) after excluding duplicates and consent withdrawals. Patients assigned to the slower rate received a mean of 1162 mL on the first day vs 1252 mL for the control group. By day 90, 1406 of 5276 patients (26.6%) in the slower rate group had died vs 1414 of 5244 (27.0%) in the control group (adjusted hazard ratio, 1.03; 95% CI, 0.96-1.11; P = .46). There was no significant interaction between fluid type and infusion rate (P = .98).
Conclusions and Relevance: Among patients in the intensive care unit requiring fluid challenges, infusing at a slower rate compared with a faster rate did not reduce 90-day mortality. These findings do not support the use of a slower infusion rate.
Trial Registration: ClinicalTrials.gov Identifier: NCT02875873.
The study population is too heterogeneous for it to produce any meaningful results.
As an ICU physician, fluid resuscitation is a cornerstone of my practice, as it is with many inpatient clinicians. This study is a tremendous effort to study fluid management in ICU patients and likely relevant to all hospitalized patients. While the results are not exciting or surprising (a slower fluid bolus for rate of 333 mL/h vs. standard 999 mL/h did not impact any major outcomes), these are the best data we have on fluid resuscitation outside of the surgical or trauma settings. Clinicians can feel more confident in prescribing fluid boluses at a rate of 999 mL/h. Hopefully, this encourages more research on fluid management, as this is such a common aspect of inpatient practice and is quite bereft of high-quality evidence like this.
As a hospitalist, these results are what I would have expected. I will use this article to manage patients with multiple comorbidities, especially with heart failure and CKD.