Urine color is often under-appreciated as one of many considerations in working up a patients clinical status (especially in the intensive care unit). “Highlighter” yellow urine is often seen in patients on B vitamin complexes (it’s a water soluble vitamin and your body doesn’t need 1,000% of the daily requirement, lol), red/brown urine can be related to hemoglobin/myoglobin breakdown (hemolysis, rhabdo, etc.), orange urine is often seen in patients on rifampin (an antibiotic) or phenazopyridine (an analgesic dye for the GU tract), and of course “purple urine in porphyria.”
Green urine is a rare but often benign sign in many intensive care units (ICUs) which I’ve most commonly seen caused by the intraoperative administration of methylene blue for refractory vasoplegia and rarely after propofol usage (due to phenol-based metabolites). It’s important to remember that in the latter case, the presence of green urine does not mean renal function is impaired or propofol is inadequately metabolized (in fact, its metabolism exceeds that of the hepatic metabolism since propofol can also be broken down in the lungs, kidneys, etc.).
Other causes for green urine include other dyes (ie, indigo-blue), long-standing obstructive jaundice, and other medications (TCAs, H2 blockers, NSAIDs).
Drop me a comment below with questions and your thoughts/experiences!