Episode 2 – Urologic Emergencies (iTunes) 

The Free Open Access Medical Education (FOAM) – The Skeptics Guide to Emergency Medicine (SGEM) Episode 71

The podcast reviews: Tamsulosin for ureteral stones: a systematic review and meta-analysis of a randomized controlled trial.

• Paper’s Conclusion:  ‘Tamsulosin is a safe and effective medical expulsive therapy choice for ureteral stones. It should be recommended for most patients with distal ureteral stones before stones are 10 mm in size. In the future, high-quality multicenter, randomized and placebo- controlled trials are needed to evaluate the outcome.”

The SGEM’s analysis:  Tamsulosin is useless in most ED patients with ureteral colic unless their stone size exceeds at least 4mm.

The Bread and Butter

We summarize some key topics from the following readings,  Tintinalli (7e) Chapters 95, 97; Rosen’s (8e) Chapter 99, but the point isn’t to just take our word for it.  Go enrich your fundamental understanding yourself!

Renal Colic

Diagnostics

• Urinalysis demonstrating microscopic hematuria.  Note: 10-15% of patients with renal colic have no hematuria
• Imaging isn’t needed in patient’s with a history of renal colic and symptoms consistent with their previous episodes and without signs of symptoms of significant obstruction or infection.  Non-contrast CT scan is currently the standard diagnostic imaging of choice and bedside ultrasound may be used to look for hydronephrosis, but isn’t great for picking up stones.  The Ultrasound Podcast guys have a great episode on the topic.  Plain films (KUBs) are only useful in following the location of the stone after CT scan.
• Make sure you’re not dealing with a tricky abdominal aortic aneurysm.

Management

• Analgesics – nonsteroidals and, if needed, narcotics
• Anti-emetics
• Use of alpha-antagonist such as tamsulosin is controversial, as indicated in The SGEM podcast.  Tintinalli supports the use of these agents, whereas Rosen’s cautions that use of this medication is controversial.
• Disposition – home with a strainer to catch the stone and outpatient urology follow up if patient has adequate pain control and oral intake and lacks significant infection or obstruction.  Remember, stones <5mm are going to pass on their own most of the time (~95%), whereas patients with stones >8mm will undergo intervention 95% of the time.

Infected Kidney Stones – Suspect in patients with SIRS criteria or those that appear sick (don’t forget that temperature <36 C, 10% bands, <4K white blood cells, and elevated respiratory rate are all part of SIRS) and in those with signs of infection on their urinalysis.

Management

• Urgent or emergent urologic consultation to evaluate the need for drainage and for relief of the obstruction.
• Treat sepsis and shock with good sepsis care including antibiotics and fluid resuscitation but these patients may need immediate operative intervention by urology for adequate source control.  This may include a stent or percutaneous nephrostomy tube.  Call urology.

Acute Urinary Retention

Causes

• Spontaneous – Benign Prostatic Hypertrophy (BPH)
• Precipitated – a host of medications (pseudoephedrine, NSAIDs, anticholinergics), anesthesia, strictures, masses, spinal cord compression (most sensitive finding in cauda equina!), infection

Diagnosis

• Palpate the patient’s abdomen, feel for a distended bladder
• Ultrasound, checking for a post-void residual >150 cc (LxWxH x 0.52 – although, notably there are a variety of coefficients to multiply by based on the shape)
• Check a urinalysis, BUN, creatinine
• History and physical should guide further testing with regard to etiology

Management

• Treat the underlying cause (stop the offending medication, treat the infection, etc)
• Place a foley catheter to relieve the obstruction.  There is some literature on spontaneous voiding trials in the ED but this isn’t standard (see this Academic Life in Emergency Medicine article).
• Urology follow up within 3-7 days
• Admit patients with signs of sepsis, co-morbidities, or renal insufficiency (or those that won’t follow up otherwise).

Generously donated Rosh Review questions (scroll for answers)

Question 1 [polldaddy poll=8057572]

Question 2 [polldaddy poll=8077276]

Listen 

 

Answers:

1) C.  The 3 primary predictors of stone passage without the need for surgical intervention are stone size, stone location, and the degree of patient pain at discharge. The most important factor, however, is calculus size. Approximately 90% of calculi smaller than 5 mm pass spontaneously within 4 weeks.

2) A.  Indications for hospitalization: intractable nausea/vomiting, severe dehydration, pain, associated UTI, solitary or transplanted kidney, high grade obstruction.

References:

Tintinalli (8e) Chapter 97.  Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. 2011.

Ban KM, Easter JS.  Selected Urologic Problems.  Chapter 99.  Rosen’s Emergency Medicine.  (8e) p 1326-1354

Yen D, Lee C. Chapter 95. Acute Urinary Retention. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. 2011.