An 80 year old man’s sudden confusion was explained when his hospital urine bag turned purple, a sign not of anything he had taken but of a hidden urinary tract infection known as purple urine bag syndrome.
The case was shared on August 13 by Tensia, a Facebook page that posts health information.
According to the page, the man already had several health problems. He had high blood pressure, severe knee arthritis that made walking hard, and an enlarged prostate that gave him trouble passing urine.
About two weeks before he came to the hospital, his family noticed he had become confused and forgetful, was sleeping badly and had slowed down far more than they would expect from age alone.
His urine problems also got worse. He needed to go often, the flow was weak and kept stopping and starting, and he often had to strain. What worried the family most was the confusion, which was not like him, so they brought him in to be checked.
At the hospital, doctors found him drowsy and slow to answer, taking small, careful steps in a way that looked like Parkinson’s disease. They thought something in his body was affecting his brain, either an imbalance in his blood or an infection. This can bring on a state of sudden confusion called delirium, which is common in very old people.
The doctors also thought the confusion had brought out signs of Parkinson’s that no one had spotted before.
To find what was causing it, they admitted him and fitted a catheter, a thin tube that drains urine into a bag, because he could barely reach the toilet and was at risk of a fall, which can be serious at his age. At first the urine looked normal, yellow and in a normal amount.
Two days later, nurses told the doctors that the bag had turned a deep purple. Around the same time, his confusion had started to improve, then got worse again, beyond how he had been at home.
Blood tests showed a high level of white cells. A urine test found a lot of bacteria, more white cells, and a reading showing the urine was less acidic than normal. Together, these pointed to an infection in the urinary tract.
Further testing identified the two bacteria behind the infection, Morganella morganii and Enterococcus faecalis. The first can take hold when the body is weak, and it is becoming harder to treat with antibiotics in many countries.
Both germs still responded to treatment. Doctors put him on antibiotics through a drip, a combination called Piperacillin and Tazobactam sold as Tazocin, replaced the catheter, tube and bag, and treated him for dehydration and low salt levels in his blood.
Within a few days, the purple faded to a reddish tinge, then went back to normal yellow. The infection cleared, his urine returned to normal and the confusion slowly lifted. This confirmed that the infection had turned the urine purple, and that the same infection had caused his confusion.
The Tensia page explained that certain bacteria feed on a substance in food called tryptophan and turn it into two pigments, one blue (indigo) and one red (indirubin). When the two build up and mix in the bag and tube, they make purple.
This usually goes unnoticed because the bacteria often do not make enough colour, or the body and antibiotics clear the infection first. The page said that the man probably had enough because the infection had been building before he even came in.
The page added that the case is a reminder that older people with a urine infection often do not show the usual signs, such as fever, a burning feeling or stomach pain. Instead, it can show up as drowsiness, confusion or worsening memory that can look like dementia getting worse. The purple colour is not dangerous in itself, but it can be a warning that an infection is hidden underneath.
The story Purple urine signals hidden infection, not drugs, in Thai man as seen on Thaiger News.
