Urinary Tract Infection (UTI)

The protocol for Urinary Tract Infection (UTI):

Urinary Tract Infection


Let’s break it down!

Urinary tract infections (UTIs) are infections of the organs of the urinary tract and include a wide spectrum of disease severity from mild lower tract infections to upper tract diseases that can be severe and life-threatening. UTI’s are responsible for an estimated 2-3 million ED visits per year. 

Generally speaking, UTI’s occur when bacteria travel up the urinary tract, colonize, and infect the host. Urinating is key to flushing out bacteria before it can cause an infection, so when the patient is dehydrated or simply unable to pee (due to kidney stones, etc.), they are at a particularly high-risk.  Since females have shorter urethras than males, it is typically much easier for the bacteria to reach their destination. Generally speaking, there are four areas that can be infected:

  1. Urethra (Urethritis)
  2. Prostate (Prostatitis)……obviously only occurs in males.
  3. Bladder (Cystitis)
  4. Kidney (Pyelonephritis)

All of them have their own special quirks, but for the most part, this protocol revolves around Cystitis, which is the most common.  The video below provides a more in-depth discussion about the pathophysiology of the disease:


The best way to assess for a UTI is to perform a urinalysis with microscopic examination. However, since this capability probably won’t be available to you in the field, a good history and physical will have to do.

These symptoms all make sense.  The urinary tract is inflamed and irritated from the bacteria which is going to cause the dysuria (52-58% specific), frequency (60% specific), and urgency (78-88%).  The bacteria is also going to cause the urine to be cloudy or dark, and if you’ve never smelled a UTI before, you’ll know it when you do. It reeks!

For patients experiencing more severe UTI’s, such as pyelonephritis, you’ll likely get additional symptoms. They may experience flank/back pain (, as well as more systemic symptoms such as fever (69-79% specific) and nausea/vomiting. One good way to differentiate a lower UTI from something like pyelonephritis is to check for “CVAT”, which stands for Costovertebral Angle Tenderness, which is 82-84% specific. Below is a video showing how to assess for it, which you should check with all of your suspected UTI patients:

The first round of antibiotics (your choice of Ceftriaxone or TMP-SMZ) is for the treatment of the UTI itself.  The far majority UTI’s are caused by Escherichia coli (Yes, the same bacteria mostly found in your poop!) with the second most common type being Klebsiella pneumoniae, both of which are gram-negative.  Ceftriaxone and TMP-SMZ both cover these bacteria pretty well, plus a few others that might cause the infection.

In addition, we’re also going to give the patient Azithromycin, This macrolide antibiotic isn’t necessarily good for urinary tract infections, but it will provide antibiotic coverage for any potential sexually transmitted infections that we may have missed, specifically chlamydia or gonorrhea.

SMZ-TMP DS | Antibiotic For Pets | Medi-Vet

3. Treat per Pain Management protocol
UTIs can get pretty painful, especially if it’s an upper UTI. These patients may require narcotic analgesia. For patients who you suspect of having renal colic (pain due to kidney stones) NSAIDs like Ketorolac may work particularly well due to ureter pain being mostly prostaglandin-mediated. 

Hospira 00409379501 - McKesson Medical-Surgical

4. PO Hydration
Drinking plenty of fluid is crucial because we ultimately want the patient to generate more urine so that they can flush out the bacteria from their urinary tract.

Hydrating for Both Performance and Life | Military.com

5. If fever, CVAT, back pain, or flank pain, suspect pyelonephritis or renal colic and treat per Flank Pain protocol
And of course, if you see any systemic symptoms or clear pain where the upper urinary tract is, then you’re going to have to deviate from this protocol.  Both pyelonephritis and renal colic/kidney stones are covered in the Flank Pain protocol.

10 Kidney Infection Symptoms; Warning Signs & Early Symptoms

Lower urinary tract infections are treated every day with great success.  In fact, many UTIs will often go away on their own, regardless of any treatment.  But if symptoms are getting worse or the initial antibiotics aren’t knocking it down, then that should be a clear indicator that at least a Routine evacuation 


Bonus Information:

  • Cranberry Juice 🍷has NOT been definitively shown to prevent or treat UTIs.  However, many patients have had positive results with it so as long as it doesn’t deter them from seeking definitive care, I don’t see a problem with it 
  • Although it makes sense that urinating after sexual intercourse should help dispel any bacteria that may have been inoculated into the urinary tract, doing so has not actually been shown to reduce recurrent UTIs 
  • Although many experts have suggested that wiping from back to front will expose the urinary tract to fecal bacteria, there hasn’t been any profound evidence for this either🙅‍♂️ .  However, it probably wouldn’t be bad advice if you told someone who has frequent UTIs to wipe from front to back.


Good luck out there!



Brandon Simpson, PA-C
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