Intra-abdominal hypertension is an under-appreciated cause of acute renal failure.

Increased intra-abdominal pressure (IAP), known as intra-abdominal hypertension (IAH) is increasingly being recognized as an important predictor of adverse outcomes in critically ill patients. The prevalence of IAH has recently been estimated at between 32 and 65% in both medical and surgical intensive care units [1,2]. High grade IAH may result in abdominal compartment syndrome (ACS), where increased pressure in a closed anatomic space threatens the viability of surrounding tissues and organs [1,2]. Renal dysfunction is one of the earliest and most common presentations in ACS. As IAP increases, glomerular filtration rate (GFR) decreases progressively and anuria may ensue [3,4]. Cases of acute renal failure (ARF) quickly reversed by abdominal decompression (DC) have been well-documented in the surgical literature [3], but surprisingly, only a handful of cases were reported in the nephrology literature [4]. Even standard nephrology textbooks such as Brenner & Rector’s do not list ACS or IAH as a cause of ARF [5]. ACS is usually not considered by nephrologists as a likely cause of ARF as there are other more classic causes such as acute tubular necrosis or volume depletion, especially in non-surgical settings. We report three cases of acute oliguric renal failure which met the definition of ACS, and two cases in which the diagnosis of ACS was very likely based on the clinical course. We then review the mechanisms of renal failure in ACS, and propose some clinical criteria that could aid clinicians suspect and pursue the diagnosis of this potentially reversible cause of ARF.