International Journal of Collaborative Research on Internal Medicine & Public Health

Keywords

Acute renal failure, hydronephrosis, hypertension

Introduction

Acute renal failure (ARF) is a can be defined as decline in renal function within hours to days. [1] It can be classified mostly as prerenal, renal and postrenal based on etiology. Prerenal, renal, and postrenal causes are responsible for 50-70%, 20-40%, 5% of ARF, respectively. [2]

Case Presentation

A 93 year old male with past medical history of hypertension, type 2 DM and history of prostate cancer treated with radiation 5 years ago presented with weakness, fatigue and decrease oral intake. He had an elevated baseline creatinine ranging from 1.4 to 1.6.

Initial labs showed AKI (BUN ~204 and Creatinine ~12.43) with hyperkalemia (7.5) and metabolic acidosis (CO2 11). Renal ultrasound showed normal size kidneys with normal echogenicity and no hydronephrosis bilaterally. A Foley was placed with 500 cc of urine output immediately upon placement. Has had a total of 1250 cc of urine output over next 2 h.

Patient was aggressively treated with intravenous sodium bicarbonate infusion, fluids and hyperkalemia cocktail.

His creatinine normalized within next 12-24 h with hydration and Foley placement and intravenous fluid resuscitation.

Discussion

Mostly, clinicians don’t suspect from post renal ARF unless hydronephrosis is present. But post renal ARF may be without hydronephrosis in 3 circumstances.3 Firstly, in the early stage of obstruction, hydronephrosis cannot be determined; because it takes a certain time such as 1-3 days. Secondly, in retroperitoneal fibrosis, post renal ARF can be seen without hydronephrosis. Lastly, if there is mild obstruction, hydronephrosis may not be seen. Post obstructive outlet obstruction should always be in differentials in cases presenting with acute renal failure. In our case there was an element of pre renal etiology but a lot of physicians will rule out post obstructive etiology as a cause with absence of hydronephrosis, though the problem can be easily resolved and resulted in a quick resolution of problem. Complete and partial obstruction for prolong period can lead to irreversible damage and can be life threatening.

References

1. Lameire N., Van Biesen W., Vanholder R. Acute renal failure. Lancet 2005; 365: 417-430.
2. Brady HR., Singer GG. Acute renal failure. Lancet 1995; 346: 1533- 1540.
3. Burton DS., Rascoff JH., Golden RA., Spinowitz BS., Charytan C., et al. Diagnosis of urinary tract obstruction and hydronephrosis In Nondilated obstructive nephropathy. Arch Intern Med 1983; 143: 696.