Abstract: SA-PO991

Refractory Hypokalemia Secondary to Intestinal Pseudo-Obstruction

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Gorantla, Vijaya Kumar, University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Gyamlani, Geeta G., Veterans Affairs Medical Center, Memphis, Tennessee, United States
  • Wall, Barry M., Veterans Affairs Medical Center, Memphis, Tennessee, United States
Background

Intestinal pseudo-obstruction, a functional obstruction of the bowel seen in multiple medical and surgical conditions, is likely due to autonomic imbalance. Water and electrolytes can be sequestrated in dilated intestinal loops resulting in profuse watery diarrhea and hypokalemia. This is likely mediated by upregulation of BK channels in colonic mucosa, which are thought to be responsible for hypersecretion of potassium, which drives the osmotic diarrhea. Stool potassium concentrations are significantly elevated.

Methods

A 64-year old male with hypertension, GERD, muscular weakness and alcoholism was admitted for evaluation of hypotension and electrolyte abnormalities: serum potassium 1.4mEq/L, magnesium 1.3mg/dL and calcium 7.2mg/dL for which oral and intravenous replacement was initiated. Due to persistent hypokalemia (<2.5mEq/L) Nephrology was consulted. On initial examination, he was afebrile, normotensive, appeared thin built with soft, distended abdomen with hyperactive bowel sounds and poor muscle tone. Abdominal X-ray showed adynamic ileus. After evaluation, proton pump inhibitor intake and alcoholism were thought to be the cause and were discontinued and potassium replacement was continued. Renin (<0.15ng/ml/hr), aldosterone(<1ng/dL), random urine potassium (7 meq/L), creatinine, osmolality were measured to calculate fractional excretion of potassium (2%) and transtubular potassium gradient (TTKG) (<2) suggesting extrarenal potassium losses. He continued to have abdominal distention with intermittent profuse watery diarrhea. Infectious and GI workup, including colonic mucosal biopsies were negative. He had recurrent admissions for abdominal distention, diarrhea and hypokalemia. Abdominal imaging continued to show dilated loops of small bowel and colon (>13cm). Stool electrolytes were measured as sodium (<20mEq/L) and potassium (162mEq/L). This pattern was consistent with intestinal pseudo-obstruction causing extrarenal potassium loss.

Conclusion

Clinicians should be aware of this unusual etiology for extrarenal potassium wasting and the need for aggressive potassium replacement until the pseudo obstruction resolves. Measurement of stool electrolytes are necessary to confirm the etiology of the refractory hypokalemia.