dfAugmented renal clearance in critically ill trauma patients admitted to Chris Hani Baragwanath Academic Hospital Intensive Care Unit: a retrospective review of data

Abstract

Augmented renal clearance (ARC) is enhanced elimination of solutes by the kidneys. Patients with ARC have normal plasma creatinine concentrations and typically display a hyperdynamic circulation, with increased cardiac output, resulting in renal hyper-perfusion and increased creatinine clearance (CrCl). The resultant enhanced elimination of renally cleared agents may be associated with sub-therapeutic drug levels and lower minimum inhibitory concentration of antibiotics. There is a paucity of studies describing the occurrence and features of ARC in a South African population. Methods We conducted a retrospective review of data of all trauma patients admitted to the Intensive Care Unit (ICU) at Chris Hani Baragwanath Academic Hospital (CHBAH) during a one-year period to identify those with features of ARC. Results- Of the 96 trauma patients admitted to CHBAH ICU over the study period, 38 met inclusion criteria. Of these, 29 showed features of ARC (CrCl > (130mL/min/1.73 m2). Most patients with ARC were male 75.9% (n=22/29), with a mean age of 32.7 years (SD 11.3 years) and mean weight of 75.7 kg (SD 14.0). Overall, 76.3% (n=29/38) of patients had at least 1 episode of ARC during the first 7 days of ICU admission. CrCl was highest on day 4 occurring in 77.8% (n=14/18) of patients with an average CrCl of 180 ml/min/1.73m2 and again at day 7 in 77.8% of patients with an average CrCl of 163 ml/min/1.73m2 The majority of those with ARC 86.2% (n=31) had undergone emergency surgery on admission, and 25% (n=9) had required inotropic support during their ICU stay. There was no significant difference in modified Sequential Organ Failure Assessment (p=0.836), Acute Physiology and Chronic Health Evaluation (p=0.081), or Injury Severity Scores (p=0.422) between patients with ARC and those with no features of ARC. Conclusion A high prevalence of ARC was detected in our South African ICU population. As this was a single centre, retrospective audit, with a limited sample size, further studies exploring the presence and clinical impact of ARC in the South African trauma population and in other populations are still needed.