Calvin L. Strand

Solitary Blood Cultures as a Quality Assurance Indicator

For patients with suspected bacteremia, at least two separate blood cultures are recommended to achieve maximum sensitivity and to properly interpret re sults. Since a single blood collection may signify an improper procedure with serious consequences if the diagnosis of blood stream infection is missed, we in vestigated this problem with studies at three teaching hospitals (A, B, and C) and by a survey of 38 other hospitals. The incidence of solitary blood cultures ranged from 1 to 99% (median 26%) at the surveyed institutions. Among the cases investigated at hospitals B and C, between 10 and 30% of solitary blood cul tures were not clinically indicated, while most of the others were caused by the physician not knowing that one culture was insufficient or by failure to complete the diagnostic plan. Focused concurrent intervention at hospital B was associated with reductions in soli tary blood cultures from 40.0 to 24.6% (p = 0.045) and a decline in those not indicated from 38.1 to 12.5% (p = 0.192). Global educational efforts at hos pital A were associated with a decrease in solitary blood culture rates from 52 to 37% (p = 0.016). These results show that blood culture practice varies widely among institutions in spite of consensus recommen dations for proper specimen collections. We estimate that, nationwide, up to 18,000 etiologic diagnoses of bacteremia are missed annually because of this prob lem. Monitoring institutional solitary blood cultures is recommended as a test utilization indicator and as the basis for improving blood culture practice.

Improved Resolution of Diagnostic Problems in Selected Prostate Needle Biopsy Specimens by Using the ASAP Workup: A Prospective Study of Interval Sections vs New Recut Sections

This study assessed the value of an atypical small acinar proliferation (ASAP) workup consisting of preparing new recut sections from the paraffin block and performing H&E-stained sections and immunostains (using the antibody cocktail for p63, cytokeratins 5 and 14, and alpha-methylacyl coenzyme A racemase) on the slides. We compared the ASAP workup with the interval workup, the common practice of performing the same immunostains on the saved interval sections, in 105 cases because of focal glandular atypia on the original H&E-stained sections. There were no specimens in which only the interval workup showed a changed diagnosis, but there were 23 specimens (21.9%) in which the preliminary diagnosis was changed to a definitive diagnosis of carcinoma (10 specimens) or a specific benign diagnosis (13 specimens) based solely on the findings of the ASAP workup. The ASAP workup is recommended as a very useful histologic tool for resolving diagnostic problems in prostate needle biopsy specimens.

Improved Histologic Identification of Helicobacter pylori by Immunohistochemistry Using a New Novocastra Monoclonal Antibody

Objective: Gastric infection with Helicobacter pylori is associated with many upper gastrointestinal diseases including H. pylori -associated gastritis, and it is standard practice to routinely perform histochemical or immunohistochemical stains on endoscopic gastric biopsies. Several studies have shown that immunohistochemical staining with specific H. pylori antibodies shows the highest sensitivity and specificity in detecting H. pylori . This study was conducted to compare a new Novocastra monoclonal antibody, clone UCL3R, to a polyclonal antibody, NCL-HPp, in known cases of H. pylori infection of the stomach. The following 3 performance characteristics were assessed: sensitivity, quality of organism morphology, and non-specific background staining. Methods: Two pathologists with expertise in gastrointestinal pathology examined 300 biopsies that previously demonstrated H. pylori gastritis using the polyclonal antibody immunohistochemical method (NCL-HPp). The sensitivity of the 2 methods was comparable with 96.2% of the cases identified by the monoclonal antibody method and 98.5% identified by the polyclonal antibody method. The pathologists scored the 2 methods for quality of organism morphology and background staining. Results: The data showed the monoclonal method was superior for quality of organism morphology and background staining. The sensitivity of the 2 methods was comparable with 96.2% of the cases identified by the monoclonal method and 98.5% identified by the polyclonal method and the specificity was 100%. Conclusion: The new H. pylori monoclonal antibody shows improved quality of organism morphology and reduced background staining compared to the polyclonal antibody. * H. pylori : Helicobacter pylori MALT : mucosa-associated lymphoid tissue H&E : hematoxylin and eosin IHC : immunohistochemical MHP : monoclonal H. pylori antibody PHP : polyclonal H. pylori antibody ER2 : Epitope Retrieval solution 2 H. heilmannii : Helicobacter heilmannii PPIs : proton pump inhibitors

Evaluation of the automated leukocyte differential count in emergency department patients

This study compares the results of the leukocyte three-part differential count as determined by the Coulter S-Plus IV in 104 consecutive patient samples from the emergency department with results obtained by conventional visual differential. A high rate (40%) of instrument rejection was found, reflecting the high prevalence of disease and hematologic abnormalities in the patient population. No clinically significant abnormality went undetected, demonstrating that the automated leukocyte three-part differential is effective as a screening test in the emergency department patient population.