Kayexalate-Induced Colonic Mucosal Injury with Pseudomembrane Formation and Ischemic Change: A Complication in a Post-Total Knee Replacement Patient—A Case Report

This case report delves into the intricate medical challenges encountered during the management of a 78-year-old woman with a history of systemic hypertension and a recent left total knee replacement. The patient developed urinary retention and hyperkalemia during her hospitalization, resulting in additional complications, including bilateral hydronephrosis and a urinary tract infection caused by E. coli ESBL.

During her hospital stay, the patient experienced rectal bleeding, prompting a consequential colonoscopy that unveiled substantial pathology in the left colon ([Fig. 1]). Notably, areas of edema and linear deep ulcers approximately 30 cm from the anal verge were identified. There was an active oozing from one of the ulcers, which was managed with adrenalin injection and hemoclip application. The sigmoid colon and upper rectum displayed a pseudomembrane, encompassing approximately 10 cm of the colon, accompanied by bluish pigmentation. Subsequent histopathological examination of biopsies obtained during the colonoscopy unexpectedly revealed the presence of Kayexalate crystals. Further histopathological findings validated stercoral ulcers with bleeding, pseudomembrane colitis with pigmentation, and ischemic colitis. Linear ulcerations in the left colon raised concerns about ischemic or vasculitic etiology.

Addressing the complexity of the case required a collaborative, multidisciplinary approach involving urology, gastroenterology, and psychiatry. Gradual improvement in renal function was observed following the discontinuation of antihypertensive medication.

Results: The Results section outlines the key findings from the diagnostic procedures, emphasizing the unexpected discovery of Kayexalate crystals during histopathological examination. Additionally, the section highlights the identified pathologies in the left colon, including areas of edema, linear deep ulcers, pseudomembrane formation, and ischemic colitis. The collaborative efforts of the multidisciplinary team are discussed, and the gradual improvement in renal function following the discontinuation of antihypertensive medication is presented.

Conclusion: The case underscores the complex nature of postoperative complications in elderly patients with multiple comorbidities. It emphasizes the vital role of a holistic and collaborative medical approach in managing such cases effectively. The unexpected identification of Kayexalate crystals in the colonic mucosa further emphasizes the association with the patient's recent hyperkalemia and the utilization of Kayexalate medication. The case report concludes by emphasizing the need for heightened awareness and careful consideration of potential complications in patients undergoing similar interventions.

Fig 1 Ulcers in rectum.

Figure 2

Publication History

Article published online:
22 April 2024