Clinical presentation and prognostic factors in sodium monofluoroacetate intoxication

Background: The diagnosis of sodium monofluoroacetate intoxication in humans is usually based on a history of ingestion and clinical findings. Although several previous reports have described the clinical course and outcome of patients who ingested this drug, prognostic indicators of short-term survival are not available. Methods: A retrospective study of 38 consecutive cases of sodium monofluoroacetate poisoning at the National Cheng Kung University Hospital, 1988-1993, to analyze the clinical findings and to predict mortality. Results: Seven of 38 patients (18%) died. The most common symptom was nausea or vomiting (74%). The most frequent ECG finding was nonspecific ST-T and T wave abnormalities (72%). Hypocalcemia (42%) and hypokalemia (65%) were the common electrolyte abnormalities. The clinical and laboratory characteristics were compared for the survival and mortality groups. Significant differences in hypotension, respiratory rate, pulse rate, creatinine, potassium, elevated alanine aminotransferase, pH, PCO₂, APACHE II score, and subjective respiratory distress were noted. Discriminant analysis identified hypotension, increased serum creatinine, and decreased pH as the most important predictors of mortality, with sensitivity of 86% and specificity of 96%. Conclusions: Hypotension and the early onset of metabolic acidosis and increased serum creatinine are associated with poor short-term survival. These prognostic variables can be useful in the care of patients with suspected sodium monofluoroacetate intoxication. It is suggested that all such patients should be observed intensively for at least 48 h.