Objective: To determine the biochemical effects of restricting the use of chloride-rich intravenous fluids in critically ill patients.
Design: Prospective, open-label, before-and-after study.
Setting: University-affiliated intensive care unit.
Patients: A cohort of 828 consecutive patients admitted over 6 months from February 2008 and cohort of 816 consecutive patients admitted over 6 months from February 2009.
Interventions: We collected biochemical and fluid use data during standard practice without clinician awareness. After a 6-month period of education and preparation, we restricted the use of chloride-rich fluids (0.9% saline [Baxter, Sydney, Australia], Gelofusine [BBraun, Melsungen, Germany], and Albumex 4 [CSL Bioplasma, Melbourne, Australia]) in the intensive care unit and made them available only on specific intensive care unit specialist prescription.
Measurements and Main Results: Saline prescription decreased from 2411 L in the control group to 52 L in the intervention group (p < .001), Gelofusine from 538 to 0 L (p < .001), and Albumex 4 from 269 to 80 L (p < .001). As expected, Hartmann's lactated solution prescription increased from 469 to 3205 L (p < .001), Plasma-Lyte from 65 to 160 L (p < .05), and chloride-poor Albumex 20 from 87 to 268 L (p < .001). After intervention, the incidence of severe metabolic acidosis (standard base excess <−5 mEq/L) decreased from 9.1% to 6.0% (p < .001) and severe acidemia (pH <7.3) from 6.0% to 4.9% (p < .001). However, the intervention also led to significantly greater incidence of severe metabolic alkalosis (standard base excess >5 mEq/L) and alkalemia (pH >7.5) with an increase from 25.4% to 32.8% and 10.5% to 14.7%, respectively (p < .001). The time-weighted mean chloride level decreased from 104.9 ± 4.9 to 102.5 ± 4.6 mmol/L (p < .001), whereas the time-weighted mean standard base excess increased from 0.5 ± 4.5 to 1.8 ± 4.7 mmol/L (p < .001), mean bicarbonate from 25.3 ± 4.0 to 26.4 ± 4.1 mmol/L (p < .001) and mean pH from 7.40 ± 0.06 to 7.42 ± 0.06 (p < .001). Overall fluid costs decreased from $15,077 (U.S.) to $3,915.
Conclusions: In a tertiary intensive care unit in Australia, restricting the use of chloride-rich fluids significantly affected electrolyte and acid-base status. The choice of fluids significantly modulates acid-base status in critically ill patients.
From the Department of Intensive Care (NMY, IBK, RB, GAG, GKH), the Pharmacy Department (LH), and the Department of Anaesthesia (DS), Austin Hospital, Melbourne, Australia; and the Australia and New Zealand Intensive Care Research Centre (RB, MB), Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
Currently listed as ClinicalTrials.gov NCT 00885404.
Dr. Story received a grant from Baxter. The remaining authors have not disclosed any potential conflicts of interest.
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