Experience with acute paraquat poisoning in Crete

Ten cases of acute paraquat poisonings with lethal (n = 5) and non-lethal (n = 5) outcomes are presented. Paraquat plasma and urine levels of the patients on admission (from 2 to 41 h after ingestion) at the peripheral hospitals varied from 0.4 to 6.0 and 0.5 to 12.8 micrograms/ml, respectively. Besides standard supportive treatment, hemoperfusion/hemodialysis and/or plasmapheresis were performed for therapy, which in 1 case lasted for 28 d. The pharmacokinetic data from patient paraquat elimination confirmed considerable paraquat rebound from tissues to blood circulation and marked the need for continued therapy even with undetectable paraquat plasma levels. Postmortem analysis showed that while paraquat was mainly distributed in kidney (807 micrograms/g), lung (479 micrograms/g) and liver (206 micrograms/g), amounts were also detected in thyroid (64 micrograms/g), testis (21 micrograms/g), vitreous humor (45 micrograms/ml) and cerebrospinal fluid (7.4 micrograms/ml). Paraquat crossed the placenta and concentrated there to higher levels than in the mother's blood. The fetus seemed to tolerate the mother's paraquat intoxication while dependent on placental circulation.