Introduction: Acute digitalis overdosage is characterized by high electric instability, its mortality may reach 10-15 percent even nowadays.
Purposes: To detect the possible risk factors which might predict severe intoxication.
Methods: Data of 50 patients treated at authors' department with acute digoxin poisoning over the past 8 years could be retrospectively evaluated. Cases were classified according to the Poison Severity Score (PSS). The following parameters were taken into consideration: age, sex, diseases influencing the severity of intoxication, dose of the drug, heart frequency, serum potassium and digoxin levels and vomiting. For statistical analysis a Kruskal-Wallis test and a chance-quotient calculation was applied.
Results: From 50 patients 30 were mild (PSS 1, 2), 20 were severely poisoned, which subgroup included 8 deaths (PSS 4) and 12 patients who recovered (PSS 3). Based on Kruskal-Wallis test significant differences were found in the following items: greater number of primary diseases PSS 4 vs other subgroups (p < 0.05); bradycardia PSS 4 vs PSS 2 (p < 0.05) and PSS 3 vs PSS 2 (p < 0.05); hyperkalaemia PSS 3 vs PSS 2 (p < 0.01); elevated serum digoxin level PSS 3 vs PSS 2 (p < 0.05). The risk of severe poisoning (PSS 3-4) was increased in case of hyperkalaemia, bradycardia, vomiting (p < 0.001), and if the patients' age and if the drug dose exceeded 65 years or 10 mg, respectively (p < 0.05).
Conclusions: The predictive risk factors concerning severe acute digoxin poisoning are profuse vomiting, hyperkalaemia and bradycardia. The predictive risk factors of fatal outcome are age over 65 years associated with primary disease, vomiting and bradycardia.