More care is not always better care. The things we do for patient or for our convenience can backfire and lead to medical complications. Placement of the Foley urinary catheter is one such example. Many patients would much rather have the convenience of a Foley catheter during their hospital stay than experience the perceived embarrassment of incontinence. Many nurses would rather have the convenience of a Foley catheter as well to keep their patients from soiling their sheets with urine. Unfortunately, these catheters can cause more harm than good. Here's a rare cause of acute renal failure from placement of a urinary catheter. For the internists in training out there, remember your three general causes of acute renal failure.
- Post obstructive.
Internists can diagnose 95% of all cases of renal failure without invoking the diagnostic skills of a nephrologist if they remember the basics they were taught in medical school and residency. We are internists. This is what you do for a living. A reader sent me this case of an 88 year old demented, bed bound nursing home patient who presented to the ER in extremis:
She had all the signs of sepsis, except she had hypertension. These nursing home folks always have a Foley catheter, even if it's a difficult Foley catheter insertion. There's something about nursing homes and Foley catheters. You can't have one without the other. If you're an internist in training, understand that having a nurse obtain a straight cath sample of urine can help you accelerate your diagnostic evaluation. All old person from a nursing home should get a straight cath urinalysis if they experience any of the following problems:
- It doesn't matter what they came in for, get a urine.
In this situation, the 88 year old patient wasn't making urine, even with her Foley catheter securely in place. How is that possible? How can someone not make urine when they have an indwelling catheter in place? Either they are completely anuric (making no urine), or their Foley catheter isn't draining. Those are the only two possible ways. In this case, this woman's foley was obstructed and prevented any urine from escaping the bladder.
What you see in the first CT image cut is bilateral hydronephrosis (obstructed kidneys). Note the bilateral nature of the dilated ureters and kidneys involved in the hydronephrosis. To get both kidneys obstructed, the obstructing lesion must be somewhere distal to both ureters in order to obstruct fluid flow out of both kidneys. Unless you had the unfortunate bad luck to get big obstructing stones trying to pass down the ureters of both kidneys at the same time, the lesion must be distal to the ureters to obstruct flow. In a man, bilateral hydronephrosis is often the result of an enlarged prostate. For men and women, this can also mean the presence of a bladder tumor or clot obstructing both ureters. In this case, it was an obstructed Foley catheter that caused a massive pooling of urine in the bladder. See the CT cut below. That little white dot in the middle of that giant round thing, that's the Foley catheter in a bladder filled with urine. It's as if they plugged the drain hole in the sink and turned on the faucet.
No wonder this lady had hypertension and tachycardia. Her demented little soul was probably writhing in pain for days at the nursing home. She probably had a rip roaring bladder infection too from the accumulation of static urine in this post obstructive cause of hydronephrosis. In order to get anuria ( no urine output) from hydronephrosis, you must obstruct urine flow from both kidneys. You see, a hydronephrotic kidney will still often produce urine. But the obstructing lesion is what prevents the urine from being eliminated and the back pressure causes the kidneys to dilate.
This gives the illusion that the patient isn't making urine, when in fact they are. The urine just can't exit the body/ Sometimes the easiest explanation is the most likely explanation. In the case of no urine output, I ask nursing staff to please flush the catheter. Too many times in my years as a hospitalist I have seen this solve the problem of low or no urine output. This nursing someecard helps to explain.