The failure of CDC screening questionnaire to efficiently detect elevated lead levels in a rural population of children.

BACKGROUND: In 1991, the Centers for Disease Control and Prevention (CDC) lowered the level for lead toxicity from 25 micrograms/dL to 10 micrograms/dL and published guidelines recommending that all children be tested for blood lead level at 12 months of age and again, if possible, at 24 months. The guidelines also called for periodic universal screening of children between the ages of 6 and 72 months using the CDC's lead screening questionnaire. However, blindly following these recommendations may result in unnecessary patient discomfort, wasted time, and extra expense. According to the CDC guidelines, deviation from this practice requires the determination of the local prevalence of lead poisoning. The purpose of this study was to measure the local prevalence of elevated blood lead levels (EBLL) and to assess the utility of the CDC's lead screening questionnaire in a rural setting. METHODS: Three hundred seventy-six children living on the Navajo Reservation in Arizona were studied. A consecutive series evaluation at well-child visits between the ages of 6 and 72 months was conducted using the CDC lead screening questionnaire and blood lead levels measured by anodic voltammetry. RESULTS: Of 376 children, 368 had their blood levels tested. Eight children tested positively with an EBLL of > or = 10 micrograms/dL for a prevalence of 2.2%. Three hundred twenty-three completed questionnaires; 83 (25.7%) of these children had false-positive results. The sensitivity and specificity of the CDC lead screening questionnaire were 42.9% and 73.7%, respectively. The positive predictive value of the questionnaire was 3.5%. CONCLUSIONS: In this rural population of children, the prevalence of lead poisoning was low, and the CDC lead screening questionnaire failed to efficiently identify those children with lead toxicity. Screening such a population using the CDC guidelines will result in unnecessary discomfort for children and will squander limited resources of time and money. Physicians who care for children should know the local prevalence of EBLL in order to effectively follow the CDC's recommendations for lead screening.

Failure of hematocrit to detect iron deficiency in infants.

BACKGROUND: Infants of low-income families have three times the risk of iron deficiency as those of families above the poverty level. Psychomotor deficits have been associated with iron deficiency once it produces anemia. High-risk infants are usually screened for iron deficiency between 9 and 12 months of age with a hematocrit measurement. This type of screening may miss iron-deficient infants who are not yet anemic. METHODS: In the well-child clinics for low-income families in Houston, Texas, a hematocrit (Hct) < or = 33% is the standard screening criterion for iron deficiency. Three hundred twenty-one infants between the ages of 9 and 18 months had capillary blood drawn for Hct testing. Serum ferritin levels were simultaneously measured. RESULTS: Six (1.9%) of the 321 infants were anemic, but none because of iron deficiency. Fifty-one infants (15.9%) were iron deficient (ferritin <10 micrograms/L), none of whom were anemic. Hematocrit and ferritin levels did not correlate statistically. CONCLUSIONS: The Hct is not an adequate screening test for iron deficiency in this population of infants. Although this population is usually considered high-risk, iron deficiency was mild. Selective screening of high-risk infants in this population may be appropriate, but a more sensitive screening test is required. Further studies are needed to determine the prevalences of iron deficiency in this and other high-risk populations.

Fluoxetine-induced SIADH: a geriatric occurrence?

After major depression was diagnosed in a 83-year-old woman, fluoxetine was prescribed. Six days later she became delirious and weak, necessitating hospitalization. She was found to have hyponatremia secondary to fluoxetine-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH). Recovery was complete after discontinuation of the medication.

Papanicolaou smear adequacy: the effect of the sampling sequence.

BACKGROUND: The purpose of this study was to determine the effect of ectocervical sampling methods and sequence on Papanicolaou smear adequacy. METHODS: A randomized clinical trial was performed using either a curved cytologic sampling brush or Ayre spatula for ectocervical sampling before or after a straight sampling brush for endocervical sampling. RESULTS: The adequacy of ectocervical smears, as measured by the presence of columnar cells or squamous metaplasia, differed significantly among the four techniques studied. When the Ayre spatula was used second, 115 (69 percent) of 167 ectocervical smears were adequate compared with 75 (48 percent) of 156 smears when it was used first. Likewise, when the curved brush was used second, 116 (67 percent) of 172 ectocervical smears were adequate compared with 80 (50 percent) of 160 smears when it was used first. One hundred ninety-six (59 percent) of 332 ectocervical smears obtained with a curved brush were adequate compared with 190 (59 percent) of 323 ectocervical smears obtained with a spatula. CONCLUSIONS: The differences among the four ectocervical sampling techniques studied were due to the sequence of ectocervical sampling rather than the instrument utilized. We recommend that an ectocervical sample be obtained only after a straight brush is used to obtain an endocervical sample.

Erythropoietin production in renal tumors.

A review of the pertinent literature on the relation of erythropoietin production to the presence of renal neoplasm suggests that erythropoietin may be produced either directly by the tumor or indirectly by its physical effect on the adjoining normal renal tissue. The most commonly found tumors which are associated with elevated levels of serum and urinary erythropoietin are the hypernephromas. However, the presence of erythropoietin and an associated erythrocytosis even here occurs only relatively infrequently. Some studies have demonstrated the presence of erythropoietin activity in tumor tissue itself but erythropoietin has not been isolated from renal tumor tissue. In some patients with Wilms' tumor, erythropoietin blood levels may also be increased; however, erythrocytosis in these patients is not a characteristic feature. Other renal tumors rarely produce erythrocytosis and presumably no erythropoietin. Possible explanations for the production of erythropoietin by renal tumors are discussed.

The measurement of erythropoietin.

The bioassay of erythropoietin in animals is reviewed. The techniques employed are those of hypertransfusion and hypoxia using polycythemic mice.