If duration of membrane rupture and internal fetal monitoring are confirmed to be associated with transmission, interventions may be possible to decrease the risk of transmission.

Purpose: To review information on performance characteristics for tests that are commonly used to identify acute and chronic hepatic injury. Data Sources and Study Selection: A MEDLINE search was performed for key words related to hepatic tests, including quality specifications, aminotransferases, alkaline phosphatase, γ-glutamyltransferase, bilirubin, albumin, ammonia, and viral markers. Abstracts were reviewed, and articles discussing performance of laboratory tests were selected for review. Additional articles were selected from the references. Guideline Preparation and Review: Drafts of the guidelines were posted on the Internet, presented at the AACC Annual Meeting in 1999, and reviewed by experts. Areas requiring further amplification or literature review were identified for further analysis. Specific recommendations were made based on analysis of published data and evaluated for strength of evidence and clinical impact. The drafts were also reviewed by the Practice Guidelines Committee of the American Association for the Study of Liver Diseases and approved by the committee and the Association’s Council. Recommendations: Although many specific recommendations are made in the guidelines, some summary recommendations are discussed here. Alanine aminotransferase is the most important test for recognition of acute and chronic hepatic injury. Performance goals should aim for total error of <10% at the upper reference limit to meet clinical needs in monitoring patients with chronic hepatic injury. Laboratories should have age-adjusted reference limits for enzymes in children, and gender-adjusted reference limits for aminotransferases, γ-glutamyltransferase, and total bilirubin in adults. The international normalized ratio should not be the sole method for reporting results of prothrombin time in liver disease; additional research is needed to determine the reporting mechanism that best correlates with functional impairment. Harmonization is needed for alanine aminotransferase activity, and improved standardization for hepatitis C viral RNA measurements.

Purpose: To review information on the use of laboratory tests in screening, diagnosis, and monitoring of acute and chronic hepatic injury. Data Sources and Study Selection: A MEDLINE search was performed for key words related to hepatic diseases, including acute hepatitis, chronic hepatitis, alcoholic hepatitis, cirrhosis, hepatocellular carcinoma, and etiologic causes. Abstracts were reviewed, and articles discussing use of laboratory tests selected for review. Additional articles were selected from the references. Guideline Preparation and Review: Drafts of the guidelines were posted on the Internet, presented at the AACC Annual Meeting in 1999, and reviewed by experts. Areas requiring further amplification or literature review were identified for further analysis. Specific recommendations were made based on analysis of published data and evaluated for strength of evidence and clinical impact. Recommendations: Although many specific recommendations are made in the guidelines, only some summary recommendations are listed here. In acute hepatic injury, prothrombin time and, to a lesser extent, total bilirubin are the best indicators of severity of disease. Although ALT is useful for detecting acute and chronic hepatic injury, it is not related to severity of acute hepatic injury and only weakly related to severity of chronic hepatic injury. Specific tests of viral markers should be the initial differential tests in both acute and chronic hepatic injury; when positive, they are also useful for monitoring recovery from hepatitis B and C.

For years, quantitative blood cultures found only limited use as aids in the diagnosis and management of septic patients because the available methods were cumbersome, labor intensive, and practical only for relatively small volumes of blood. The development and subsequent commercial availability of lysis-centrifugation direct plating methods for blood cultures have addressed many of the shortcomings of the older methods. The lysis-centrifugation method has demonstrated good performance relative to broth-based blood culture methods. As a result, quantitative blood cultures have found widespread use in clinical microbiology laboratories. Most episodes of clinical significant bacteremia in adults are characterized by low numbers of bacteria per milliliter of blood. In children, the magnitude of bacteremia is generally much higher, with the highest numbers of bacteria found in the blood of septic neonates. The magnitude of bacteremia correlates with the severity of disease in children and with mortality rates in adults, but other factors play more important roles in determining the patient's outcome. Serial quantitative blood cultures have been used to monitor the in vivo efficacy of antibiotic therapy in patients with slowly resolving sepsis, such as disseminated Mycobacterium avium-M. intracellulare complex infections. Quantitative blood culture methods were used in early studies of bacterial endocarditis, and the results significantly contributed to our understanding of the pathophysiology of this disease. Comparison of paired quantitative blood cultures obtained from a peripheral vein and the central venous catheter has been used to help identify patients with catheter-related sepsis and is the only method that does not require removal of the catheter to establish the diagnosis. Quantitation of bacteria in the blood can also help distinguish contaminated from truly positive blood cultures; however, no quantitative criteria can invariably differentiate contamination from bacteremia.

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