Oral potassium poisoning: a retrospective review of the National Poison Data System 2010-2021

Introduction: Oral potassium poisoning can be life-threatening. The study aimed to describe patterns of oral potassium poisoning in adult and pediatric populations and characterize its clinical presentation and management as reported by United States poison centers. Methods: This is a retrospective review of the National Poison Data System from 1 January 2010 through 30 June 2021. We descriptively analyzed cases involving single substance, oral potassium salts. In a second step, we requested a subset of case-specific narratives for cases that resulted in major outcome or death, as well as cases where patients received any of the following therapies: whole bowel irrigation, sodium bicarbonate, calcium, insulin or hemodialysis. We classified hyperkalemia by expected toxicity: mild (peak potassium concentration <6.5 mEq/L), moderate (peak potassium concentration 6.5 to <8 mEq/L) or severe (peak potassium concentration >= 8mEq/L). Results: The National Poison Data System included 1,820 cases, 52.3 percent being adults. Among adult cases, 20% (n = 189) resulted in a moderate effect, major effect or death. Among pediatric cases aged <10 years, all exposures were unintentional. Analysis of 49 case narratives showed a median peak potassium concentration of 7.1 mEq/L (interquartile range 5.4-8.6) and a moderate correlation with the dose ingested (r = 0.66). Severe hyperkalemia was associated with QRS complex widening (P < 0.001), peaked T-waves (P = 0.001), and neurological symptoms (P = 0.04). Whole bowel irrigation was associated with mild hyperkalemia (P = 0.011), and hemodialysis was associated with severe hyperkalemia (P < 0.001). Discussion: Analysis of data showed that therapy to promote intracellular shift of potassium is the mainstay of management of oral potassium poisoning, followed by hemodialysis. Limitations: Poison center data are susceptible to reporting bias. National Poison Data System data are affected by completeness and accuracy of reporting from health care providers and the lay public. Conclusions: Single substance, oral potassium poisoning, reported to United States poison centers, is mostly unintentional and rarely results in hyperkalemia.