Emphysematous Pyelonephritis: a Review of a Rare Condition

Emphysematous pyelonephritis (EPN) is a rare condition which is potentially life threatening. It is characterised by gas formation within the collecting system, renal parenchyma and/or perirenal tissues. Diabetes is the single most common risk factor for the development of EPN. Other risk factors include urinary tract obstruction and immunocompromise. Escherichia Coli is the most common pathogen. EPN is characterised by fever, loin pain and systemic upset. Gold standard diagnosis and classification of EPN is made with contrast CT. Classification can be used as a prognostic indicator for mortality and to guide management. EPN may be managed conservatively or surgically. Patients managed conservatively are resuscitated and administered with intravenous antibiotics. Intravenous fluid, glucose control for diabetics and acid base balance are vital components for primary management. For those in whom conservative management is unsuccessful, a parenchymal drain may be considered to drain gas or a collection of pus. Patients with hydronephrosis will benefit from a nephrostomy or JJ stent insertion. Patients who have failed minimally invasive surgical intervention or who have a number of risk factors predisposing them to EPN should undergo either immediate or delayed nephrectomy. With treatment for EPN now moving away from nephrectomy towards less invasive interventions, mortality rates for EPN are improving but remaining high.