Pink urine syndrome in an anuric patient during continuous renal replacement therapy: A case report

Pink urine syndrome is a rare, poorly understood condition, often prompted by obesity, insulin resistance, and the drug propofol. It is characterized by pink urine or urine sediment and occurs in the absence of a heme or food-based pigment. The pathophysiology of this syndrome is not yet fully understood but is linked to a uric acid metabolism disorder. Pink urine syndrome is less familiar to anesthesiologists than other propofol infusion complications. Our case report aims to highlight this rarely encountered syndrome, whose both diagnosis and therapeutic may be challenging. We have reported the first case of this syndrome evidenced by the change in color of the effluent bag during continuous veno-venous hemofiltration (CVVHF).

A 61-year-old woman was admitted to the intensive care unit following a recovered cardiorespiratory arrest due to ventricular arrhythmia. She was placed in hypothermia, sedated with propofol (300 mg/h), and started on CVVHF for oligo-anuric acute kidney injury associated with severe metabolic acidosis. A few hours after initiation of CVVHF, the effluent bag turned bright pink. Given the pink color of the effluent bag and the hypothesis of propofol-induced pink urine syndrome, propofol was replaced by midazolam. After stopping propofol, the color of effluent bag lightened. Unfortunately, the patient died on the third day of hospitalization due to diffuse cerebral edema.

We report here the first case of pink urine syndrome as revealed by the change in color of the contents of the CVVHF effluent bag in an anuric patient. This syndrome is rare but significant in anesthesia/intensive care settings, where propofol is a frequently used sedative. Knowledge of this syndrome appears to be important to avoid irrelevant additional investigations and to optimize the therapeutic strategy.