Septic shock due to pyonephrosis

Case contribution: Dr Radhiana Hassan


  • A 62 years old lady
  • Underlying DM and HPT on medication, morbid obesity BMI 38, body weight 80 kg
  • Presented with left flank pain for one day, radiating to the back, pain score 5/10
  • Associated with vomiting and feeling feverish
  • Similar pain on and off for about one month
  • Clinically not septic looking, vital signs stable (BP=144/76), HR 72 bpm, DXT=11
  • Abdomen soft, mild tenderness at epigastric and left hypochondriac, renal punch negative
  • Given tramadol stat dose, metoclopramide, ranitidine and MMT in ED
  • One day after admission, BP drop 81-92, 54-56, not picking up on fluid resuscitation
  • HR 102 bpm
  • Admitted to ICU, started on noradrenaline
  • Intubated, CVP line inserted
KUB radiograph shows no significant finding
Ultrasound abdomen

Ultrasound findings:

  • Bilateral kidneys are normal in shape, size and echogenicity.
  • The BPL of right kidney is 10.7 cm and left kidney is 10.8 cm.
  • Mild to moderate left hydronephrosis and left proximal hydroureter is noted.
  • Unable to trace the distal ureter due to bowel gaseous shadow.
  • No focal lesion or perinephric collection bilaterally.
  • Urinary bladder is normal.
CT scan abdomen and pelvis in axial plane soft tissue window post contrast
CT scan abdomen pelvis in sagittal and coronal plane soft tissue window post contrast

CT scan findings:

  • No intra-abdominal collection.
  • Left kidney is bigger  compared to right kidney.
  • Minimal fat stranding at left perinephric region.
  • Moderate left hydronephrosis and hydroureter (yellow arrows). The density of hydronephrosis measures HU:5-11. No fluid levels, air pockets seen within the collecting system. No abnormal enhancement of ureteric wall/lining.
  • A calculus is seen in the distal ureter (red arrows) measuring about 1.3×0.7 cm.
  • Urinary bladder is not well distended. No obvious focal lesion within.
  • Bowel loops are grossly normal. Uterus is normal. No adnexal mass.
  • No abnormal lymphadenopathies.
  • Right consolidation and left atelectasis of lung bases.

Progress of patient:

  • Urgent bilateral retrograde pyelopgram and stenting done in OT
  • Left gross hyodroureter and hydronephrosis, pus aspirated
  • Stented
  • Culture of blood, urine and pus: E. coli
  • Urine C& S: candida species
  • Discharged well after 16 days admitted

Diagnosis: Urosepsis/septic shock due to pyonephrosis


  • This case illustrate the limitation of CT evaluation to distinguish simple hydronephrosis from pyonephrosis
  • Fluid attenuation measurements are not reliable.
  • And as in this case, no other CT features are present to suggest pyonephrosis.
  • In clinical setting, pyonephrosis should be suspected when the clinical symptoms of fever and flank pain are present, combined with radiologic evidence of urinary tract obstruction.
  • Emergent diagnosis and prompt treatment is very important for good outcome
  • Complications of pyonephrosis include sepsis, xanthogranulomatous pyelonephritis, renal abscess, perinephric abscess and fistula.
Author: radhianahassan