Abstract
Background
Patients with cirrhosis are more susceptible to develop AKI than the non-cirrhotic individuals. AKI has an estimated prevalence of approximately 20% to 50% among hospitalized patients with cirrhosis. Physicians caring for patients with cirrhosis should recognize the acute or chronic character of renal disease, the causes of renal injury, the clinical conditions leading concomitantly to AKI and liver dysfunction, and the prognostic factors associated with the progression of AKI. Hypovolemia (due to diuretics, hemorrhage and diarrhea), acute tubular necrosis (ATN), sepsis, nephrotoxic agents (such as nonsteroidal anti-inflammatory drugs, aminoglycosides and/or radiological contrasts) and hepatorenal syndrome (HRS)-type 1 are the most common causes of AKI in cirrhotic patients.
Objective
To evaluate the sensitivity of fractional excretion of urea (FEUrea) vas a diagnostic biomarker for different causes of acute kidney injury in liver cirrhosis.
Patients and Methods
This study was conducted in co-operation between Tropical Medicine Department, Ain-Shams University and the Gastroenterology and Hepatology Department, Theodor Bilharz Research Institute between July 2019 to January 2020. It included 70 adult Egyptian patients admitted for treatment of complications of cirrhosis who fulfilled the eligibility criteria and compared to 10 cirrhotic patients without renal impairment. All patients were subjected to; full history taking, thorough clinical examination, laboratory investigations, Child-Pugh score was calculated for admission and urine samples were collected for urinary urea and creatinine levels to calculate FEUrea.
Results
Concerning the gender distribution in this study, male to female percent was 40 (57.10%) males and 30 (42.90%) females for gender, respectively. As regards to the causes of AKI, there were 24 (34.30%) PRA, 7 (10.00%) HRS and 39 (55.70%) ATN for final diagnosis. In the current study, there was significant difference (P = 0.0001; P < 0.05) in FE urea % among PRA, HRS and ATN groups (26.28±2.89, 11.76±3.44, and 47.37±10.53, respectively). Findings showed a higher FEUrea cut-off for ATN (>33%) compared to lower cut-off values for PRA (<33% and >21%) and HRS (<21%).
Conclusion
FEUrea was found to be an excellent simple tool for the differential diagnosis of AKI in patients with decompensated cirrhosis and ascites. FEUrea has also proven to be a useful “tubular injury” marker by differentiating ATN from non-ATN with high diagnostic accuracy (Sensitivity and Specificity exceeding >90%). FEUrea was found to be a good alternative and noninvasive tool for differentiating causes of AKI in cirrhotic patients instead of other non-available or expensive markers.
Acute kidney injury with oxalate deposition in a patient with a high anion gap metabolic acidosis and a normal osmolal gap
