Prognostic factors and toxicokinetics in acute fenitrothion self-poisoning requiring intensive care

We aimed to evaluate prognostic factors and toxicokinetics in acute fenitrothion self-poisoning.

We reviewed 12 patients with fenitrothion self-poisoning admitted to the intensive care unit between 2003 and 2006. We compared the characteristics, initial vital signs, physiological scores, corrected QT interval on electrocardiogram and laboratory data (serum fenitrothion concentration and cholinesterase activity) of non-survivors and survivors. Furthermore, we evaluated the correlation between the prognostic factors and severity of poisoning (lengths of intensive care unit and hospital stays), and the toxicokinetics of the patients.

In the 2 non-survivors, the estimated fenitrothion ingestion dose and the serum fenitrothion concentration at the emergency department and at 24 h after ingestion were significantly higher than those in the 10 survivors. (P = 0.008, 0.003, and 0.04, respectively). In the 10 survivors, the serum fenitrothion concentration at 24 h after ingestion was significantly correlated with the lengths of intensive care unit and hospital stays (P = 0.004 and 0.04, respectively); however, the initial vital signs, physiological scores, corrected QT interval on electrocardiogram at the emergency department, and serum cholinesterase activity did not show any correlation. In five patients successfully fitted to a two-compartment model, the distribution and elimination half-lives were 2.5 and 49.8 h, respectively, which is compatible with the slow and prolonged clinical course of fenitrothion poisoning. CONCLUSION. Estimated fenitrothion ingestion dose and serum fenitrothion concentration at the emergency department and at 24 h after ingestion may be useful prognostic factors in acute fenitrothion self-poisoning. Furthermore, we should take care for the patients whose serum fenitrothion concentration is high.