#EMconf: Obstructive Pyelonephritis
Obstructive pyelonephritis is a urologic emergency that requires emergent decompression, broad spectrum antibiotics and monitoring for urosepsis
The management of this patient includes resuscitation of sepsis as well as management of acute renal failure
-Due to complete urinary obstruction, frequent reassessment of her respiratory status necessary during fluid resuscitation
-Acute renal failure will cause a number of complications; including uremia, platelet dysfunction and severe electrolyte disorders (hyperkalemia) that may result in an arrhythmia
-This patient required dialysis for emergent treatment of severe electrolyte abnormalities and uremia preceding her emergent stone removal, followed by admission to the ICU
Stone removal can be completed via ureteral stent placement by urology or percutaneous nephrostomy (PCNT) by interventional radiology
-Final decision should be made in conjunction with these specialists, as well as anesthesia if the patient is going to require sedation for the procedure
-There are currently only two small trials comparing percutaneous nephrostomy to stent placement, which show no clear advantage of one approach
-Consider stent: IR not available, failed PCNT, uncorrected coagulopathy, minimal hydro, challenging anatomy for PCNT
-Consider PCNT: Urology not available, failed stent attempt, difficult urologic access anatomically, concern for impacted stone, unable to tolerate general anesthesia
Additional pearls on obstructive pyelonephritis:
-Negative urinalysis does not rule out obstructive pyelonephritis, as the urine above the stone may be infected and the urine distal to the stone may be sterile
-During acute unilateral renal obstruction, most patients have no rise in serum creatinine because the unobstructed, normal kidney can function as high as 185% of its normal capacity
-Mortality rates are 9% in those treated with decompression and 19% in those without decompression
-The risk of urosepsis is increased after decompression, however there is no clear evidence describing increased risk based on method of decompression (percutaneous nephrostomy vs ureteral stent)
References:
-Marian, T., Miller, NL. Treatment of the Infected Stone. Urologic Clinics of NA. Elsevier Inc; 2015 Nov 1;42(4):459–72
-Manjunath AS, Hofer M. Urologic Emergencies. Medical Clinics of NA. Elsevier Inc; 2018 Mar 1;102(2):373–85
-Ramsey S, Robertson A, Ablett MJ, Meddings RN, Hollins GW, Little B. Evidence-based drainage of infected hydronephrosis secondary to ureteric calculi. J Endourol. 2010 Feb;24(2):185–9
-Tintinalli et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th Ed. New York: McGraw hill Education, 2016. Print