Hypokalemia associated with acute colonic pseudo-obstruction in an ESRD patient.

We report an anuric, end-stage renal disease (ESRD) patient undergoing peritoneal dialysis (PD) who developed acute colonic pseudo-obstruction causing a prolonged hospitalization. He also developed severe hypokalemia with a serum potassium (K+) as low as 2.4 mEq/L and required 180 - 240 mEq of potassium chloride per day for more than a month to correct it. While PD K+ losses often contribute to hypokalemia, the PD K+ loss was estimated to be only 39 mEq/day. Therefore, PD could only contribute modestly to the recalcitrant hypokalemia observed during the episode of pseudo-obstruction. It has been shown, however, that patients with colonic pseudo-obstruction have enhanced colonic K+ secretion. In addition, experimental studies in patients with chronic kidney disease (CKD) have demonstrated that colonic K+ excretion can be up to 3 times greater than in individuals with normal renal function. This increase may involve an upregulation of the large conductance K+ channel (maxi-K), also known as the BK channel, in the apical border of the colonocytes. We suggest that ESRD may have placed our patient at a greater risk of developing hypokalemia as his colon may have already adapted to secrete more K+. Clinicians should be aware of this extrarenal K+ wasting etiology in patients with colonic pseudo-obstruction, particularly in those with CKD where such a severe K+ deficit is not anticipated and, therefore, may inhibit more rigorous K+ replacement. PMID: 28025959 [PubMed - as su...
Source: Clinical Nephrology - Category: Urology & Nephrology Authors: Tags: Clin Nephrol Source Type: research