VOTW: Emphysematous Pyelonephritis

This weeks’s VOTW is brought to you by Dr. Dozois!

A 60 yo female w/ hx of DM presented with 1 week of progressively worsening R flank pain, fever and vomiting. Symptoms and UA was consistent w/ pyelonephritis. A POCUS was performed which showed…

Clip 1 and 2 shows the right kidney with echogenic foci with “dirty shadowing” in the renal parenchyma concerning for air within the kidney. This is concerning for emphysematous pyelonephritis.  A hypoechoic region towards the inferior pole of the kidney is concerning for a perinephric abscess.

Emphysematous pyelonephritis is a rare, severe gas-forming infection of the renal parenchyma with mortality rates ranging from 40-90%. Most (95%) are associated with uncontrolled diabetes. Usual pathogen is E. Coli. Management options include IV antibiotics plus percutaneous nephrostomy, or ureteral stenting, or nephrectomy which is becoming less and less preferred.

POCUS for pyelonephritis?

  • POCUS is insensitive for pyelonephritis alone and kidneys usually appear normal. Abnormalities are identified in only 25% of cases. The most common finding is focal/segmental hypoechoic regions (edema).

  • POCUS is useful for assessing complications of pyelonephritis including hydronephrosis, perinephric abscess, and emphysematous pyelonephritis all of which would prompt CT imaging and urologic evaluation.

  • Considering POCUSing a patient with pyelonephritis if they are worsening despite antibiotics, if there is a concern for associated downstream obstruction or if they are in septic shock.

Back to the patient

The patient was actually a transfer from an outside hospital for emphysematous pyelonephritis seen on CT. Urology was consulted who admitted the patient to the SICU for a planned nephrectomy in the morning 😊