Augmented Creatinine Clearance: The other end of the spectrum of Renal dysfunction in Burn patients

Abstract

Introduction: Augmented renal clearance (ARC)

was identified many years ago, but its importance is now

being increasingly described. In critically ill patients,

particularly in the initial and acute phases of severe

trauma, sub-arachnoid hemorrhage, burns and sepsis, a

subset of patients with normal serum creatinine levels have

increased urinary solute loss, presenting as an

underestimated problem called as augmented renal failure.

Augmented renal failure is defined as increase in

creatinine clearance (CLCR) more than 130 ml/ min/1.73

m2. The aim of this study was to evaluate the incidence of

Augmented renal clearance in patients admitted with burn

injury & having a normal serum creatinine by estimation of

creatinine clearance using Modification of Diet in Renal

Disease index (MSRD) formula. Methods: This was a

retrospective, observational study done in Burns ICU of our

hospital. A total of 44 consecutive patients from August

2012 December 2016 were included. The Creatinine

clearance (CLCR) was calculated using the MSRD formula

during the hypermetabolic phase of thermal flame burns

(Day 3-15). Patients with electric burns, chemical burns,

diabetes mellitus, acute renal failure were excluded.

Results: Twenty patients (45%; 20/44) had a CLCR above

130 mL minute-1 1.73 m-2 on post burn day 5, out of these

80% (16/20) were younger than 40 years. The F:M ratio of

patients with CLCR above 130 mL minute-1 1.73 m-2 was

2.1:1. Only 4/44 patients had a CLCR below 60 mL minute-1

1.73 m-2. Thirty (30/44) patients had at least one episode

wherein the CLCR was greater than 130 mL

minute-1 1.73m-2 during post burn day 5, day 10 or day 15.

Conclusions: In burn patients with normal serum

creatinine, CLCR, can be higher than 130mL minute-1

1.73m-2 especially in younger patients (<40 years) and in

women.

The measurement of CLCR should be proposed as routine for

burn patients in order to adjust dose regimen, especially

for drugs with renal elimination.