Perinephric abscess

Related Subjects: |Pyelonephritis and Urosepsis (UTI) |Pyonephrosis |Perinephric abscess |Acute Kidney Injury (AKI) / Acute Renal Failure |Renal/Kidney Physiology |Chronic Kidney Disease (CKD)

A perinephric abscess should be suspected if a patient remains febrile after 4 to 5 days of receiving adequate antibiotic therapy for pyelonephritis.

About

• A complication of UTI with abscess formation around kidney

Aetiology

• Abscess within the perinephric space within Gerota's fascia
• It may extend beyond into psoas muscle and pelvis

Organisms

• E coli and other gram negatives
• Staphylococcus aureus may be haematogenous spread e.g. Endocarditis
• Klebsiella pneumonia, Candida

Risks

• Diabetes mellitus, pregnancy, urinary tract infection
• Abnormal structure in the urinary tract, Large renal stones
• Neurogenic bladder, Vesicoureteric reflux
• Obstructive tumour, Papillary necrosis
• Polycystic kidney disease
• IV drug abuse, Dialysis

Clinical

• Severe flank Pain and fever and fatigue
• Pyuria and dysuria may follow a pyelonephritis
• There may be urinary tract obstruction

Investigations

• FBC, U&E, Elevated CRP and WCC
• Urine culture is not sensitive and can identify the responsible bacteria in only 30%.
• Blood cultures can be useful
• Abdominal CT: soft-tissue or fluid attenuation in perirenal space. Can involve the psoas muscle and extend to the pelvis. Gas may be present. Ring enhancement with contrast
• USS renal: may show collection

Complications

• Sepsis, Pneumonia, Subphrenic abscess
• Rupture into the peritoneum or through the diaphragm
• Empyema

Management

• ABC, IV fluids and IV antibiotics should be started e.g. Augmentin and Gentamicin
• Urgent Urology review and usually drained if > 3 cm in size or failed medical treatment
• Ultrasound-guided percutaneous abscess drainage or CT guided dependant on the visibility and accessibility.

References