COMMENTARY

Chloride-Liberal vs Chloride-Restrictive Fluid Strategies in the ICU

Greg Martin, MD

Disclosures

April 02, 2013

Association Between a Chloride-Liberal vs Chloride-Restrictive Intravenous Fluid Administration Strategy and Kidney Injury in Critically Ill Adults

Yunos NM, Bellomo R, Hegarty C, Story D, Ho L, Bailey M
JAMA. 2012;308:1566-1572

Summary

Normal saline has 40% higher chloride than human plasma despite being roughly isotonic. Chloride has known effects on renal function (renal vasoconstriction and decrease in glomerular filtration) and acid-base balance ("bicarbonate dilutional acidosis" or "hyperchloremic metabolic acidosis").[1]

Given the relative high frequency of acute kidney injury (AKI) in critically ill patients, it is conceivable that fluid administration may contribute to AKI development. The authors of this study sought to determine if a chloride-restrictive intravenous fluid strategy in critically ill patients would be associated with a decreased incidence and severity of AKI compared with a chloride-liberal intravenous strategy.

This study was a prospective before/after design conducted during two 6-month periods with an intervening 6-month wash-out period. During the initial period, routine care included the administration of chloride-rich, normal saline solution. During the follow-up period, chloride-rich solutions were restricted and instead balanced solutions were available on the formulary (a lactated Hartmann solution and a balanced Plasma-Lyte® solution).

There were 760 patients in the first period and 773 patients in the later period. Chloride administration decreased from 694 to 496 mmol/patient on average, and the mean serum creatinine level change while in the intensive care unit (ICU) was less (+22.6 μmol/L vs +14.8 μmol/L, P = .03). The incidence of injury and failure class of RIFLE (risk, injury, failure, loss, end-stage kidney disease)-defined AKI was 14% vs 8.4% (P < .001) and the use of renal replacement therapy (RRT) was 10% vs 6.3% (P = .005). After adjustment for covariates, the association between chloride and both AKI and the need for RRT remained the same (both with an odds ratio of 0.52). There were no differences in hospital mortality, hospital or ICU length of stay, or need for RRT after hospital discharge.

The authors concluded that the implementation of a chloride-restrictive strategy in the ICU was associated with a significant decrease in the incidence of AKI and use of RRT.

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