Acute kidney injury

Case history #1

A 65-year-old male smoker with diabetes mellitus, hypertension, dyslipidaemia, and chronic kidney disease presents with chest pain. ECG changes suggest an acute myocardial infarction. He is taken for an urgent coronary angiogram. Three days later, he is noticed to have developed an elevated serum creatinine, oliguria, and hyperkalaemia.

Case history #2

A 35-year-old man with a history of congenital valvular heart disease undergoes a dental procedure without appropriate antibiotic prophylaxis. Several weeks later, he presents with fever and respiratory distress. He is intubated, and Streptococcus viridans is isolated in all blood cultures drawn at the time of admission. Echocardiography demonstrates a mitral valve vegetation. Laboratory tests reveal a rising serum creatinine and a reduction in urine output. Urinalysis reveals more than 20 white blood cells, more than 20 red blood cells, and red cell casts. Urine culture is negative. Kidney ultrasound is unremarkable. Serum erythrocyte sedimentation rate is elevated. 

Other presentations

Rarer presentations include AKI secondary to:

• Vasculitis

  • AKI may be associated with systemic symptoms such as arthralgia, myalgia, and/or rash. Urinalysis will demonstrate blood and protein.

• Interstitial nephritis

  • Patients may present with fever, rash, and/or arthralgia with leucocytes on urinalysis. There may be a history of a new medication being commenced.

• Atheroembolic injury

  • AKI may occur following vascular catheterisation or systemic anticoagulation resulting from atheroembolic injury.

• Obstruction

  • AKI secondary to abdominal masses or an enlarged bladder may be found on examination or by imaging. Patients may be otherwise asymptomatic.