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The cause of neonatal sepsis must be rapidly identified and treated because the condition of a sick young newborn can rapidly deteriorate. Depending on the apparent nature of the sepsis, deep cultures (blood and cerebrospinal fluid), or superficial cultures (from gastrointestinal aspirate, external ear canal and umbilicus drainage) are taken to determine the cause of infection and sepsis, and antibiotic therapy. To explore the role that these culture results play in managing antibiotic therapy, a retrospective review was undertaken. The medical records of 66 infants with early onset neonatal sepsis were studied. All infants had deep cultures taken shortly after birth, and prior to the administration of antibiotics. Superficial cultures were also collected. Factors taken into consideration included: the source and results of each culture, and the time and date reported; antibiotics used, dosage and duration of treatment; and the clinical course of the infant. The impact and influence of superficial cultures on the antibiotic regimen was positive if: antibiotics were changed after a positive superficial culture report and negative deep cultures; the antibiotic regimen was altered after a positive superficial culture report, regardless of deep culture status; and the antibiotic regimen was not changed after positive superficial culture report, negative deep cultures, and clinical well being. The principal outcome of this study revealed that, based on superficial cultures, no decision impact was felt in the antibiotic treatment of 98 percent of the neonates and 90 percent of those with positive superficial cultures. The value, if any, of the superficial cultures should be thoroughly reviewed. (Consumer Summary produced by Reliance Medical Information, Inc.)

The purpose of our study was to analyze the use of febrile agglutinin (FA) serologic tests in the diagnosis of Salmonella (typhi and paratyphi), Rickettsia, Brucella, and Francisella infections. Data were collected in a retrospective chart study of 202 titer requests covering a 42-month period at our teaching hospital. We found that no diagnoses were made by utilizing complete six-antigen FA panels. Three cases of infection were diagnosed serologically, all three with more discriminately selected single-antigen titers. These three cases each had a positive epidemiological history suggestive of disease prior to ordering FA tests. Our data suggest that the FA tests (especially the Salmonella group antigen) are an overutilized set of laboratory tests and are often difficult to interpret. It is much more important to make a diagnosis based on clinical findings and epidemiological criteria.(JAMA 1985;254:1211-1214)

Sir.—In the February 1990 issue of AJDC, Courtney et al1 described the correlation between simultaneously obtained capillary and umbilical artery catheter blood gas levels. Their study demonstrated r values of .79, .72, and .42 for pH, PCO2, and PO2, respectively, for capillary blood gases from warm, wrapped heels. Analysis of variance revealed that the major source of variation in pH was intersubject, while PCO2 and PO2 variance was accounted for by differences in arterial and capillary methods.The article described potential sources of variation in blood gas measurements. This discussion does not address the systematic difference in heparin volume between sampling techniques. Capillary specimens were collected in standard heparinized capillary tubes. These tubes are typically 100 ΜL and contain 5 to 8 U of lyophilized heparin (no volume of heparin). In contrast, arterial samples in this