Green discoloration of urine after propofol infusion
A 49-year-old female patient with a history of epilepsy and alcohol abuse was admitted to the emergency room (ER) for loss of consciousness after suffering a seizure. Central pontine myelinolysis was suspected. On admission to the ICU, the following laboratory results were found: albumin, 3.8 g/dl; total bilirubin, 3.2 mg/dl; aspartate aminotransferase (AST), 209 U/L; alanine transaminase (ALT), 50 U/L; blood urea nitrogen (BUN), 9.2 mg/dl; and creatinine, 0.8 mg/dl. Mechanical ventilation was instigated under sedation with midazolam. As frequent neurological examinations were required, midazolam was replaced with propofol. After titration, adequate depth of sedation was achieved at a rate of 4 mg/kg/h. Green urine was found 64 hours after continuous infusion of propofol (). Blood examination revealed a serum albumin level of 2.5 g/dl, total bilirubin 0.7 mg/dl, and direct bilirubin 0.4 mg/dl. Urinalysis revealed the following: pH, 6.0; urine specific gravity (SG), 1.020; bilirubin content, negative; and urobilinogen level, 8.0 EU/dl. Urine cultures were negative. We suspected propofol to be the cause of the green urine. Urine color recovered 6 hours after discontinuation of propofol. A repeat urinalysis showed: pH, 7.0; urine SG, 1.015; bilirubin content, negative; and urobilinogen level, 8.0 EU/dl. During 3 months of admission, this was the only instance of urine discoloration.