A 67 years old male with bilateral obsrtuctive nephropathy secondary to nephrolithiasis s/p bilateral ureteral stenting, followed by nephrostomy on the right due to stent failure done a week back now presents with one week of subjective fevers and chills as well as overall weakness and not feeling well.
Vitally stable but tachycardic. Lab work shows leukocytosis with neutrophilia. UA shows >50WBC, 2+ leukocyte esterase, and many bacteria.
Chart review shows previous urinary cultures not showing any growth.
So this is a typical case of sepsis secondary to UTI. Patient met the criteria of sepsis as he had leukocytosis, was tachycardic and possible source was the urinary tract.
The patient was put on IV hydration and was started on Ceftriaxone. Urine culture was growing gram negative bacilli and one set of blood cultures was growing gram positive streps.
The things that I learnt from this case were as follow:
Urinalysis is something all patients get in the ER and is rather ignored most of the times as now a days, a culture is drawn almost automatically and we the residents ignore the UA waiting for the culture. It seems like in previous days, in some, if not most hospitals, there would be a lab next to each medicine unit/floor and residents would do certain tests like UA and sputum microscopy themselves. Any of the parameters that are reported as + are actually dipsticks and as per my ID attending are pretty much useless in determining if the patient has UTI as the on going infection or has some other infection going on. The reason being that many conditions other than UTI can give you those positive results.
Nitrite can be positive on dipstick in pretty much any infection if it is severe enough. There is production of NO in sepsis due to any infection which is excreted in the urine as nitrite. The single most important value in the UA is the WBC count done under the microscope, which if high, there's most likely a UTI going on.
The choice of antibiotics:
Ceftriaxone as a choice of antibiotics while the patient is admitted is a good choice and most patient would respond since it has good activity against gram negatives which was the most common causes of UTI, The problem though is that it does not reach very high levels in the urine since it is excreted mostly through the liver and thus can lead to billiary sludge. But most patient's would respond. But if the patient had some kind of instrumentation in place in the urinary tract, quinolones might be a better choice. Mainly because they reach very high concentration in the urine. Even though now in some areas, there's up to 60% resistance to quinolones, their concentration in the urine is so high that they are still effective. So even though this patient responded well to ceftriaxone, quinolones might have been a better choice because of the stent and nephrostomy tube placement.
The bug growing in blood culture:
So the preliminary report said that there is gram positive strep growing in one set of the blood cultures. The fact that its one set could be because of two reasons. It is either a contamination or the bacteremia is small and the number of bacteria isolated are not enough to lead to significant growth in the culture. We concluded it was a contamination and decided to monitor the patient while he is on ceftriaxone. If it is coming from the urinary tract, it is most likely Strep fecalis. We decided if the patient develops fever again or if the repeat culture is positive as well, will switch to Ampicillin from Ceftriaxone since Ampicillin will cover both bugs.