Treatment of calculi depends on several factors, including size, location and composition of the stones as well as the patient’s clinical presentation. This Daily Doodle illustrates an angry septic stone, sitting at the UVJ (ureterovesical junction – where the ureter meets the bladder) in a patient who present with a swinging fever, flank pain and dysuria (pain with urination).

Acute obstructive pyelonephritis caused by an obstructing stone in the collecting system in a patient that has an upper urinary tract infection is a urologic emergency. This can lead to “pus under pressure”, possible renal failure and potentially, a life-threatening infection. Patients commonly present with flank pain, fever and infective urinary symptoms. To differentiate between obstructive and non-obstructive pyelonephritis, imaging is required.

Obstructive pyelonephritis requires urgent decompression of the collecting system with either a ureteral stent (the blue plastic flexible tube in the doodle) or percutaneous drainage in combination with antibiotic and supportive therapy. To prevent septic complications, “No attempt to manipulate or remove the stone” should be conducted [3]. The goal of emergency intervention is to promote drainage, not stone removal! “Definitive treatment of the stone should be delayed until sepsis has resolved and the infection is cleared following a complete course of appropriate antimicrobial therapy” [4].

In addition to ureteral stent placement or percutaneous drainage, patients should be started on broad spectrum antimicrobial therapy until urine or blood cultures are available to help tailor the treatment plan. To quickly review, the most common pathogens of urinary infections include the following gram-negative bacilli: Escherichia coli (50%), Proteus spp. (15%), Enterobacter and Klebsiella spp. (15%), and Pseudomonas aeruginosa (5%). Gram-positive organisms only account for 15% of cases [1].

References:

1. O. Kalra and A. Raizada. “Approach to a Patient with Urosepsis” J Glob Infect Dis. 2009 Jan-Jun; 1(1): 57–63. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2840933/
2. G. Preminger. “Management of ureteral calculi” Uptodate. December 2014. http://www.uptodate.com/contents/management-of-ureteral-calculi
3. F. Cover, P. Lawrence, R. Bell, M. Dayton. “Essentials of Surgical Specialties”. Lippincott Williams & Wilkins, 2007.
4. C. Türk (chairman), T. Knoll (vice-chairman), A. Petrik, K. Sarica, M. Straub, C. Seitz. “Guidelines on Urolithiasis”. European Association of Urology 2011. http://www.uroweb.org/gls/pdf/18_Urolithiasis.pdf

“Septic Stone” Daily Doodle by Michiko Maruyama