Trends in the management of childhood lead poisonings

It is unknown whether prompt medical management (with or without chelation therapy) and environmental intervention have beneficial effects other than stopping the progression towards symptomatic childhood lead poisoning. Stated differently, does prompt intervention have substantive beneficial effects or are untreated lead toxic children with blood lead values between 25-54 μg/dl irrevocably damaged by the time of their identification. We are carrying out a prospective treatment outcome study with CaNa2EDTA (when indicated) at our Center to hopefully answer this critical question, within the context of a multidisciplinary study. The results in 162 children indicate that environmental and medical management produce significant reductions in blood lead, erythrocyte protoporphyrin and the lead diuresis during a CaNa₂EDTA provocative test. However, CaNa₂EDTA treatment failed to decrease bone lead values dramatically, measured by L-line x-ray fluorescence, six months after enrollment in any patient group (treated or untreated with CaNa₂EDTA). The uses of L-line x-ray fluorescence in this study and K-line x-ray fluorescence measurements of lead in bone in other reported studies open a wide time window of months to years of lead exposure, compared to 30-45 days, the time of exposure captured by blood lead levels. As with all chelating agents, DMSA should be administered to children in lead free housing, after this drug's toxicity is more widely assessed. The potential capability of DMSA to ameliorate neurobehavioral deficits produced by lead must be systematically assessed and compared with CaNa₂EDTA in a randomized, controlled study before the use (s) of either drug become uncritically accepted as the treatment of choice for childhood lead poisoning, in addition to full abatement.