Burn Injury and Augmented Renal Clearance: A Case for Optimized Piperacillin-Tazobactam Dosing.

Patients with burn injuries are at high risk for infection as well as altered antimicrobial pharmacokinetics. Patients suffering from a burn injury, generally encompassing a total body surface area (TBSA) ≥ 20%, have been cited as at risk for augmented renal clearance (ARC). Our case report describes an obese patient with 3.2% TBSA partial thickness burns who suffered from burn wound cellulitis with Pseudomonas aeruginosa. Measured CLcr documented the presence of ARC, and 22.5 grams daily continuous infusion of piperacillin-tazobactam was initiated. Therapeutic monitoring of piperacillin at steady state was 78 mcg/mL, achieving the prespecified goal piperacillin concentration of 100% 4-times the minimum inhibitory concentration assuming MIC for susceptible P. aeruginosa at 16/4 mcg/mL per Clinical Laboratory Standards Institute. Available literature suggests younger critically ill patients with lower organ failure scores, and for a burn injury, a higher percentage of TBSA, are most likely to exhibit ARC which does not entirely align with the characteristics of our patient. In addition, piperacillin-tazobactam has been associated with altered pharmacokinetics in ARC, burn, and obese populations, demonstrating failure to meet target attainment with standard doses. We suggest a continuous infusion of piperacillin-tazobactam be used when ARC is identified. This case report describes the unique findings of ARC in a non-critically ill burn patient and rationalizes the need for further prospective research to classify incidence, risk factors, and appropriate antimicrobial regimens for burn patients with ARC.