Study objective: We determine the incidence of clinically important bleeding in children with superwarfarin rodenticide ingestions not treated with gastrointestinal decontamination or prophylactic vitamin K.
Methods: We prospectively studied patients younger than 6 years of age who reported to our poison center with acute unintentional superwarfarin ingestions. Patients who received gastrointestinal decontamination or prophylactic vitamin K were excluded. Forty-eight- to 96-hour prothrombin time or international normalized ratio (INR) blood tests were recommended, and telephone contact was attempted at least 3 days after ingestion.
Results: A total of 595 consecutive patients were enrolled during the 16-month study period. Fifty patients were excluded: 8 who were known to have ingested 1 pellet or less; 25 who received activated charcoal; 15 who were treated with induced emesis; and 2 who received prophylactic vitamin K. The resulting study group contained 545 patients. Eighty-two patients were lost to follow-up. Follow-up was obtained for 463 patients, including 222 by telephone contact alone, 62 by 48- to 96-hour INR, and 179 by both methods. None of the patients had clinically important coagulopathy. Two patients had an INR of 1.5 or greater (1.5 and 1.8) without symptoms. Single nosebleeds were reported in another 2 patients with normal 48-hour INRs. Another child had a small amount of blood crusted in the nose with no other symptoms and no laboratory work available. One child with a normal 48-hour INR had blood-streaked stools that were thought to be caused by an anal fissure.
Conclusion: Children with acute unintentional superwarfarin ingestions of less than 1 box may be managed without gastric decontamination or prophylactic vitamin K. Laboratory testing for coagulopathy should be reserved for cases involving clinically evident bleeding abnormalities.