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

Patients with burn injuries are at a high risk for infection as well as altered antimicrobial pharmacokinetics. Patients suffering from burn injury, generally encompassing a total body surface area (TBSA) ≥ 20%, have been cited at risk for augmented renal clearance. Our case report describes an obese patient with 3.2% TBSA partial thickness burns who suffered from burn wound cellulitis with Pseudomonas aeruginosa. Measured creatinine clearance documented presence of augmented renal clearance, 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% four-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 burn injury a higher percentage TBSA, are most likely to exhibit augmented renal clearance which does not entirely align with characteristics of our patient. In addition, piperacillin-tazobactam has been associated with altered pharmacokinetics in augmented renal clearance, burn, and obese populations, demonstrating failure to meet target attainment with standard doses. We suggest continuous infusion piperacillin-tazobactam be used when augmented renal clearance is identified. This case report describes the unique findings of augmented renal clearance 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 augmented renal clearance.