In 1991, the Centers for Disease Control and Prevention (CDC)
statement, Preventing Lead Poisoning in Young Children, redefined
elevated blood lead levels (BLLs) as those
10 µg/dL and recommended a new set of guidelines
for the treatment of lead levels
15µg/dL. In addition, universal screening was
recommended for children 9 to 72 months of age except in communities with
sufficient data to conclude that children would not be at risk of exposure.
Because at that time there were few community-based data on the prevalence of
lead poisoning in individual localities, the 1991 CDC statement basically
called for universal screening.
In response, the 1987 Statement on Childhood Lead Poisoning by the American Academy of Pediatrics (AAP) was replaced in July 1993 by Lead Poisoning: From Screening to Primary Prevention. The revised statement supported most of the 1991 CDC recommendations. Specifically, the AAP recommended "Blood lead screening as part of routine health supervision for children at about 9 through12 months of age and, if possible, again at about 24 months of age." Since publication of the 1993 AAP statement, epidemiologic investigations have identified many locales where the prevalence of elevated BLLs is so low that targeted (selective) screening is more appropriate than universal screening. In consideration of these data, in 1997 the CDC revised its 1991 guidelines, and in 1998 the AAP updated its 1993 statement on childhood lead screening.
The revised 1997 CDC guidelines are a response to inadequate
screening of high-risk children and to concerns about wasting resources by
universal screening in low-risk settings. The goal of the new CDC screening
recommendations remains unchanged: to ensure that children at risk of exposure
to lead are tested. Universal screening still is the policy
for communities with inadequate data on the prevalence of elevated BLLs and in
communities with
27% of the housing built before 1950. Targeted
screening is recommended in communities where <12% of children have
BLLs
10 µg/dL or where <27% of houses were built
before 1950. Public health authorities in each state are responsible for
setting state and local policy on childhood lead screening.
Nurses need to be aware of the local policies they practice. In a targeted screening locale, the decision to perform a lead test on a child should be based in part on the responses to a risk-assessment questionnaire. Children whose parents respond "yes" or "not sure" to any of these three risk-assessment questions should be considered for screening:
Other candidates for targeted screening include children 1 to 2
years of age living in housing built before 1950 situated in an area not
designated for universal screening (especially if the housing is not well
maintained), children of ethnic or racial minority groups who may be exposed to
lead-containing folk remedies, children who have emigrated (or been adopted)
from countries where lead poisoning is prevalent, children with iron
deficiency, children exposed to contaminated dust or soil, children with
developmental delay whose oral behaviors place them at significant risk for
lead exposure, victims of abuse or neglect, children whose parents are exposed
to lead (vocationally, avocationally, or during home renovation), and children
of low-income families who are defined as receiving government assistance
(Supplemental Feeding Program for Women, Infants, and Children; Supplemental
Security Income; welfare; Medicaid; or subsidized child care). According to the
CDC, children who receive government assistance and who live in areas where
targeted screening is recommended do not require screening if they are low risk
based on the above 3 screening questions and if <12% of the children have
BLLs
10 µg/dL in that community. In addition to
screening of children on the basis of risk questionnaires, screening for lead
exposure should be considered in the differential diagnosis of children with
unexplained illness, such as severe anemia, seizures, lethargy, and abdominal
pain.
To prevent lead poisoning, universal or targeted lead screening should begin at 9 to 12 months of age and be considered again at 24 months of age when BLLs peak. The standard procedure to determine BLLs requires a blood sample that has been collected properly by venipuncture and analyzed accurately. Venous blood samples should be used for initial screening, but a capillary (fingerstick) blood sample may be used if collected properly. A poorly collected fingerstick sample is contaminated easily by environmental lead. Fingerstick values >10 µg/dL should be confirmed with a venous blood sample. Since more than one blood sample may be needed, every effort should be made to decrease the stress of the punctures.
American Academy of Pediatrics Committee on Environmental Health: Screening for elevated blood lead levels, Pediatrics 101(6):1072-1078, 1998.
Centers for Disease Control and Prevention: Screening Young Children for Lead Poisoning. Guidance for State and Local Public Health Officials. Atlanta, GA: US Dept of Health and Human Services, Public Health Service; November 1997.
Guidelines for Atraumatic Skin/Vessel Punctures
Notes about obtaining blood samples in children: needle size and saving blood
A Cooling Spray (Fluori-Methane) Reduces Immunization Injection Pain
Use of Buffered Xylocaine for Venipuncture
See Chapter 14 in Essentials of Pediatric Nursing, 5th edition.
See Chapter 16 in Nursing Care of Infants and Children, 6th edition.
March 15, 2002