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

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.

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).

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).

Analysis of data showed that therapy to promote intracellular shift of potassium is the mainstay of management of oral potassium poisoning, followed by hemodialysis.

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.

Single substance, oral potassium poisoning, reported to United States poison centers, is mostly unintentional and rarely results in hyperkalemia.