Hypokalemia Associated with Colonic Pseudo-Obstruction (Ogilvie's Syndrome)

Recent advances in aptamer-based biosensors for potassium detection

Maintaining a stable level of potassium is crucial for proper bodily function because even a slight imbalance can result in serious disorders like hyperkalemia and hypokalemia. Therefore, detecting and monitoring potassium ion (K+) levels are of utmost importance. Various biosensors have been developed for rapid K+ detection, with aptamer-based biosensors garnering significant attention due to their high sensitivity and specificity. This review focuses on aptamer-based biosensors for K+ detection, providing an overview of their signal generation strategies, including electrochemical, field-effect transistor, nanopore, colorimetric, and fluorescent systems. The analytical performance of these biosensors is evaluated comprehensively. In addition, factors that affect their efficiency, such as their physicochemical properties, regeneration for reusability, and linkers/spacers, are listed. Lastly, this review examines the major challenges faced by aptamer-based biosensors in K+ detection and discusses potential future developments.

A Case of Acute Colonic Pseudo-Obstruction (Ogilvie's Syndrome) in a Nonsurgical Patient with Plasma Cell Leukemia

Ogilvie's syndrome, also known as acute colonic pseudo-obstruction (ACPO), is a rare, nonobstructive dilation of the colon of unclear etiology. We present the case of a patient who presented with Ogilvie's syndrome and significant hypokalemia due to colonic loss despite repletion. This case report demonstrates the difficulty in diagnosis, treatment, and outcome.

Persistent Hypokalemia in a Patient With Ogilvie's Syndrome

Ogilvie's syndrome, also known as acute colonic pseudo-obstruction (ACPO), is a rare disease characterized by acute dilatation of the colon in the absence of anatomic intestinal obstruction. It is of clinical importance because of its preponderance in elderly males in the seventh decade of life who may present with constipation or diarrhea. We present an 80-year-old male who presented with diarrhea, with laboratory investigations showing hypokalemia and a CT abdomen revealing colonic distension. The patient was wasting potassium both from colon and renal losses, despite low aldosterone levels. The patient was treated with Neostigmine, which helped relieve abdominal distention. Subsequently, potassium was corrected with aggressive replacement. This case sheds light on newer modalities of treatment such as neostigmine, as in this case.

Colonic obstruction in a tetraplegic patient: a common symptom from an uncommon cause

INTRODUCTION

It is difficult to diagnose an acute abdomen condition in people with spinal cord injury due to abnormal sensation below the injured level and multiple co-morbidities. These issues can mislead the exact diagnosis and delay proper treatment.

CASE PRESENTATION

A 57-year-old male with C4 AIS C tetraplegia developed nausea and vomiting, abdominal distension and feeding intolerance. Serum electrolytes indicated severe hyponatremia. A provisional diagnosis of pseudo-gut obstruction was made. After the failure of 48 h of conservative treatment with a nasogastric and rectal tube, abdominal CT was performed and revealed sigmoid volvulus.

CONCLUSIONS

Due to the inconclusive clinical features and lack of subjective complaints, early use of CT scan or MRI is preferable in people with SCI who are suspected of an emergency intra-abdominal condition.

Secretory diarrhea and hypokalemia associated with colonic pseudo-obstruction: A case study and systematic analysis of the literature

BACKGROUND

Colonic pseudo-obstruction (CPO) is characterized by colonic distention in the absence of mechanical obstruction or toxic megacolon. Concomitant secretory diarrhea (SD) with hypokalemia (SD-CPO) due to gastrointestinal (GI) loss requires further characterization.

AIM

To perform a systematic review of SD-CPO, report a case study, and compare SD-CPO with classical CPO (C-CPO).

METHODS

We performed a search of MEDLINE, EMBASE, Cochrane, and Scopus for reports based on a priori criteria for CPO, SD and GI loss of potassium. An additional case at Mayo Clinic was included.

RESULTS

Nine publications met inclusion criteria, with a total of 14 cases. Six studies had high, three moderate, and our case high methodological quality. Median age was 74 years (66-97), with 2:1 male/female ratio. Kidney disease was present in 6/14 patients. Diarrhea was described as profuse, watery, or viscous in 10 patients. Median serum, stool, and urine potassium concentrations (mmol/L) were 2.4 (range: 1.9-3.1), 137 (100-180), and 17 (8-40), respectively. Maximal diameter of colon and cecum (median) were 10.2 cm and 10.5 cm, respectively. Conservative therapy alone was effective in five out of 14 patients. Median potassium supplementation was 124 mEq/d (40-300). Colonic decompression was effective in three out of six patients; one had a total colectomy; three out of 14 had died. The main differences between SD-CPO and C-CPO were lower responses to treatments: conservative measures (35.7% vs 73.6%, P=.01), neostigmine (17% vs 89.2%, P<.001), and colonic decompression (50% vs 82.4%, P=.02).

CONCLUSION

SD-CPO is a rare phenotype associated with increased fecal potassium and is more difficult to treat than C-CPO.

Potassium Homeostasis, Oxidative Stress, and Human Disease

Potassium is the most abundant cation in the intracellular fluid and it plays a vital role in the maintenance of normal cell functions. Thus, potassium homeostasis across the cell membrane, is very critical because a tilt in this balance can result in different diseases that could be life threatening. Both Oxidative stress (OS) and potassium imbalance can cause life threatening health conditions. OS and abnormalities in potassium channel have been reported in neurodegenerative diseases. This review highlights the major factors involved in potassium homeostasis (dietary, hormonal, genetic, and physiologic influences), and discusses the major diseases and abnormalities associated with potassium imbalance including hypokalemia, hyperkalemia, hypertension, chronic kidney disease, and Gordon's syndrome, Bartter syndrome, and Gitelman syndrome.

Use of Aldosterone Antagonist to Treat Diarrhea and Hypokalemia of Ogilvie's Syndrome

Ogilvie's syndrome (OS) is a functional obstruction of the bowel due to an autonomic imbalance. It often presents with diarrhea and is associated with hypokalemia. We present a case of a 70-year-old male who developed severe abdominal distension, watery diarrhea, and persistent hypokalemia status after left hip arthroplasty after suffering from a femoral neck fracture due to a fall and was diagnosed with OS. The persistent hypokalemia was slow to improve despite aggressive repletion because of the high potassium losses in the stool. This is most likely mediated through the increased expression of BK channels in the colonic mucosa. Aldosterone is theorized to have a role in the regulation of BK channels. Spironolactone was subsequently given and resulted in marked improvement of the diarrhea and hypokalemia. Thus, this case suggests a novel therapeutic approach for the treatment of Ogilvie's syndrome-associated diarrhea and hypokalemia.