[Laboratory system to support liver transplantation]

It is beyond doubt that clinical examination is one of the essential issues in(living-related) liver transplantation as well as other clinical cases. To support liver transplantation, our laboratory has prepared efficient systems and has been trying to improve these systems as follows. 1) We need to construct a system to be able to comply with clinical requests. Thus, we need to know what kinds of laboratory examinations are likely to be required before, during, and after transplant surgery. In general, common laboratory examinations are sufficient to support liver transplantation. The most important thing is whether all the clinical examinations required can be assayed anytime. However, only general biochemical tests and complete blood count are provided outside standard laboratory hours by the medical technologist on duty because of staffing limitation and differences in each specialty. Therefore, we recently introduced a 24-hour on-call system in addition to the system described above. Actually, five persons in charge from each of the five groups divided by each specialty carry the pocket-bells in turns. 2) We supply a report to support the diagnosis and treatment. The report should include opinions and suggestions. A supplementary examination would be recommended if considered necessary. 3) To supply effective comments, we must improve our abilities to understand pathologic findings obtained from laboratory data. Especially, timely biopsy for the diagnosis of rejection depends on a proper interpretation of laboratory tests. Therefore, we need to investigate past cases after liver transplantation using statistical estimations and advanced examinations.

The electronic medical record: implications for the laboratory

This article describes experiences over the past 5 years with the application of a computerized patient record system and an electronic result inquiry system at Mayo Clinic. These systems now handle 56,000 results and 170,000 inquiries daily--94% relating to the laboratory. The goal of aligning laboratory services with clinical objectives is outlined with an emphasis on converting data into information and knowledge that can be used to improve patient care. Efficiencies noted thus far include a substantial reduction (68%) in phone inquires after deployment of electronic result inquiry. The electronic medical record has gone from concept to reality. As we transition into this new environment and attempt to fulfill the implicit hopes and promises this tool affords, we would wish to quantify its effect. One department lending itself to enumeration is laboratory services. The perspectives shared are gleaned from the Mayo experience and personal observations of the practice of laboratory medicine elsewhere.

Feasibility determination for use of polymerase chain reaction in the U.S. Air Force air-transportable hospital field environment: lessons learned

At present, the use of molecular probes and polymerase chain reaction (PCR) for the identification of microorganisms in body fluids or tissues is becoming more commonplace. There is an added advantage when serological or culture methods are difficult, expensive, or unavailable. Slow-growing or fastidious microorganisms, including Mycobacterium tuberculosis, spirochetes, viruses, and the dimorphic fungi, can be detected rapidly using these techniques. The presence of different chromosomal or plasmid-mediated antibiotic-resistant markers can also be determined. PCR is an extremely powerful tool that has been applied to research, and more recently it has been used to augment standard clinical applications. It is a very simple process that can amplify nucleic acid sequences, both DNA and RNA, a million times over. The sensitivity, rapidity, broad applicability, and compactness of this technology make it an ideal candidate for use in the military arena. We recently established a molecular biology laboratory at a Deployable Medical System at the Camp Parks Army Reserve Training Facility in Dublin, California. This article will briefly summarize the use of PCR and its applicability in the air-transportable hospital field environment. Proper handling, processing, and testing as well as the requirements for setting up a molecular biology laboratory will be discussed. Finally, the benefits and disadvantages of using PCR-based techniques in the deployed field environment will be considered.

[Advances in the clinical laboratory automation system of Akita University Hospital]

Abstract Clinical laboratory automation, which was widely discussed in the 1960's, was developed in late he 1970's. The computerized automatic analyzing system for clinical laboratories spread nationwide in the 1980's. Akita University Hospital was established in 1971. We have been making efforts to establish the automated clinical laboratory system. The hematological and clinical chemistry divisions were automated in 1981. In 1988, in order to establish a fully automated clinical laboratory, we introduced sample-conveying systems in each division including hematological, clinical chemistry, urinalysis, serological and immunological divisions. In 1998, we connected the sample-conveying systems which had been separately established in each division to create a fully automated clinical laboratory with an integrated sample-conveying system.

[Molecular diagnosis and new gene engineering in hematological malignancies]

Advancement molecular diagnostics in hematological malignancy has provided us with a broad menu of new assays and techniques. By integrating the data gleaned from these techniques we can formulate a more rational broad-based diagnosis. Hematological malignancies have traditionally been classified by morphological criteria. However, molecular advances have provided new insights in the genetic backbone of chimeric genes. These malignancies have shown chromosome abnormalities of translocation with chimeric genes, and revealed the rearrangement of chimeric genes by PCR analysis and quantitative PCR system. This review summarized the recent technology for detecting chimeric genes along with concepts of laboratory performance.

Sealing the cracks: VA system automatically alerts physicians when test results are available

It's typical for radiologists to call referring physicians when a test result is abnormal, but sometimes the communication falls through the cracks. The Asheville (NC) VA Medical Center uses a computer program similar to e-mail to provide a safety net.

Quantification of mitral regurgitation in the cardiac catheterization laboratory with contrast echocardiography

BACKGROUND

There is no method of quantifying the severity of mitral regurgitation (MR) from injection of tracer directly into the left ventricular (LV) cavity, a method commonly used in the cardiac catheterization laboratory.

METHODS AND RESULTS

We used a previously validated mathematical model that derives regurgitant fraction (RF) from the relative tracer washout from the left atrial (LA) and LV cavities. Thirty-nine patients referred for diagnostic cardiac catheterization with clinical evidence of possible MR were included in the study. Five milliliters of a microbubble mixture was power-injected into the LV during simultaneously performed contrast echocardiography. Relative changes in background-subtracted video intensity were measured from the LV and LA, and the resultant model-derived RF was correlated with the severity of MR on cineangiography. The severity of MR ranged from 0 to 4+ on cineangiography with corresponding model-derived RF of 0 to 0.69 on contrast echocardiography. A close linear relation was noted between angiographic severity of MR and model-derived RF on contrast echocardiography (y = 0.1x + 0.03, r = 0.89, P <.001). Contrast echocardiography was more sensitive than cineangiography for detecting mild MR.

CONCLUSIONS

We describe a new method of measuring the severity of MR in the cardiac catheterization laboratory. Apart from being quantitative, this method can be safely used during cardiac catheterization in patients in whom iodinated contrast agents may be potentially harmful.

Value of point-of-care blood testing in emergent trauma management

BACKGROUND

No prospective study demonstrates the value of point-of-care laboratory testing (POCT) in the management of major trauma.

METHODS

In a prospective, noninterventional, study of 200 major trauma patients, we evaluated the influence of a blood POCT profile (hemoglobin, Na+, K+, Cl-, blood urea nitrogen, glucose, pH, PCO2, PO2, HCO3-, base deficit, and lactate) on emergent diagnostic and therapeutic interventions. Physicians responded to a standardized set of questions on their diagnostic and therapeutic plans before and after the availability of POCT results. Management plan changes were deemed emergently appropriate, if they were influenced by the POCT results and, within the ensuing 30 minutes, the change in management was likely to reduce morbidity or conserve resources.

RESULTS

For emergently appropriate plan changes, Na+, Cl-, K+, and blood urea nitrogen were never influential, whereas in each of 6.0% of cases (95% confidence interval [CI], 3.5%-10.2%) at least one of the remaining POCT parameters was influential. An emergently appropriate change was based on hemoglobin in 3.5% of cases (95% CI, 1.0%-6.1%), blood gas parameters in 3.0% of cases (95% CI, 0.64%-5.7%), lactate in 2.5% of cases (95% CI, 1.1%-5.7%), and glucose in 0.5% of cases (95% CI, 0.1%-2.8%). All of these cases involved blunt injury.

CONCLUSION

Na+, Cl-, K+, and blood urea nitrogen levels do not influence the initial management of major trauma patients. In patients with severe blunt injury, hemoglobin, glucose, blood gas, and lactate measurements occasionally result in morbidity-reducing or resource-conserving management changes.

Functional testing after percutaneous transluminal coronary angioplasty in Canada and the United States: a survey of practice patterns

BACKGROUND

Authorities recommend various strategies to identify restenosis in patients who have undergone percutaneous transluminal coronary angioplasty (PTCA). Some authorities recommend a routine functional testing strategy, while others recommend a clinically driven strategy.

MATERIALS AND METHODS

To examine the patterns of use of post-PTCA functional testing, 89 directors of cardiac catheterization laboratories in Canada and the United States were surveyed.

RESULTS

Demographic characteristics of the Canadian and American respondents were similar, including median age (43 and 45 years, respectively) and median number of PTCAs performed each year (200 each). Canadians were more likely to employ a routine functional testing strategy than Americans (62% versus 38%), while Americans were more likely to employ stress imaging studies than Canadians (49% versus 35%). Overall, close to half (44%) of all the cardiologists employed a routine functional testing strategy. Physicians who employed a routine functional testing strategy performed the first functional test a median of three months after PTCA and the second a median of six months after PTCA. Both Canadian and American cardiologists tended to underestimate the incidence of restenosis after PTCA (33% without a stent and 18% with a stent) and to overestimate the sensitivity of exercise treadmill testing for the detection of restenosis (63%).

CONCLUSIONS

The use of functional testing after PTCA varies widely. Canadian cardiologists are more likely to employ a routine functional testing strategy than American cardiologists. Close to half of the cardiologists surveyed employed a routine functional testing strategy. These results indicate that there is little consensus regarding the use of functional testing after PTCA.

Retrospective identification and characterization of Candida dubliniensis isolates among Candida albicans clinical laboratory isolates from human immunodeficiency virus (HIV)-infected and non-HIV-infected individuals

Fungal opportunistic infections, and in particular those caused by the various Candida species, have gained considerable significance as a cause of morbidity and, often, mortality. The newly described species Candida dubliniensis phenotypically resembles Candida albicans so closely that it is easily misidentified as such. The present study was designed to determine the frequency at which this new species is not recognized in the clinical laboratory, to determine the patient populations with which C. dubliniensis is associated, to determine colonization versus infection frequency, and to assess fluconazole resistance. Over a 2-year period, 1,251 isolates that were initially identified as C. albicans by a hospital clinical laboratory were reevaluated for C. dubliniensis by inability to grow at 45 degrees C, colony color on CHROMagar Candida medium, coaggregation assay with Fusobacterium nucleatum, and sugar assimilation profiles (API 20C AUX yeast identification system). A total of 15 (1.2%) isolates from 12 patients were identified as C. dubliniensis. Ten of the patients were found to be immunocompromised (these included patients with human immunodeficiency virus infection or AIDS, cancer patients receiving chemotherapy, and patients awaiting transplantation). Thirteen isolates were highly susceptible to fluconazole (MIC, <0.5 microgram/ml). Three isolates from one patient, genotypically confirmed as the same strain, showed variable susceptibility to fluconazole. The first isolate was susceptible, whereas the other two isolates were dose-dependent susceptible (MIC, 16.0 microgram/ml). These data confirm the close association of C. dubliniensis with immunocompromised states and that increased fluconazole MICs may develop in vivo. This study emphasizes the importance of screening germ-tube-positive yeasts for the inability to grow at 45 degrees C followed by confirmatory tests in order to properly identify this species.

Spurious metabolic acidosis in hemodialysis patients

Metabolic acidosis with an increased anion gap (AG) is frequently seen among patients with end-stage renal failure that is corrected to a variable degree by chronic hemodialysis. The degree of acidosis is generally interpreted from the concentration of total carbon dioxide (tCO(2)) in blood drawn from the vascular access used for dialysis. As with many dialysis units in the United States, our laboratory studies for outpatients are performed in a central laboratory several hundred miles away and must be shipped there by air freight. We observed a consistent and clinically important difference between the tCO(2) content of samples reported from the central laboratory compared with results reported from a local university hospital chemistry laboratory. The central laboratory readings were always lower, resulting in an increase in the AG. Delays in centrifugation of the blood to separate the clot from the serum and in the initiation of analysis led to an increase in the lactate content of the samples. That increase, however, was insufficient to explain the difference in tCO(2) levels. These data suggest that something happens to the samples in transit to cause an artifactual reduction of the tCO(2) level. For many dialysis patients, the severity of their acidosis may be falsely represented by the tCO(2) content of blood samples reported from central laboratories.

Phlebotomy skills expected of career entry CLS/CLT graduates: a Missouri hospital perspective

OBJECTIVE

To determine how much, what type, and what proficiency of phlebotomy experience CLS/CLT students should have during the training program to be prepared to meet the needs of the majority of Missouri hospital employers.

DESIGN

Survey to determine the role healthcare professionals, inside and outside the laboratory, play in today's blood collection patterns and phlebotomy management.

SETTING/PARTICIPANTS

The Missouri Organization of Clinical Laboratory Science mailed 204 surveys to the Missouri Hospital Association member laboratories. MAIN OUTCOMES/CONCLUSIONS: This research examined the need for modifying phlebotomy skills of clinical laboratory science students. Data gathered from employers support the premise that entry-level competencies of CLS/CLT graduates will vary according to clinical facility size. CLS/CLT programs may use data from this study to plan phlebotomy practicums. It can be extrapolated that Missouri employers who are most likely to employ career entry graduates expect them to draw blood from 9.3 patients within one hour. Fifty-three percent of 40 to 400 bed hospitals expect graduates to perform difficult draws in at least eight types of hospital units. Laboratories are the major managers of hospital wide phlebotomy services; thus, CLS/CLT curricula should include phlebotomy management methods.

Laboratory automation and optimization: the role of architecture

The increasing automation of laboratory equipment has had far-reaching impacts on the organizational structure and spatial requirements of clinical laboratories. This report explores the changing role of the laboratory in the healthcare environment and shows the architectural impact of these changes, both inside and outside of the laboratory space.

Modular robotic workcell for coagulation analysis

BACKGROUND

Total laboratory automation (TLA) has been shown to increase laboratory efficiency and quality. However, modular automation is smaller, requires less initial capital, and requires less planning than TLA. We engineered and performed clinical trials on a modular robotic preanalytical workcell for coagulation analysis.

METHODS

Timing studies were used to quantify the efficiency of the manual processes and to identify areas in the processing of coagulation specimens where bottlenecks and long waiting periods were encountered. We then designed our modular robotic system to eliminate these bottlenecks. Our robotic modular workcell was engineered to allow a choice of specimen introduction manually, by conveyor, or by mobile robot. Additional timing studies were performed during clinical trials of the robotic system.

RESULTS

Prior to automation, the time required for preanalytical processing time was 18-107 min; after automation, it was 45-50 min. Additional improvements in workcell efficiency could be realized when high quality, prelabeled specimens were introduced into the system.

CONCLUSION

Compared with manual methods, modular automation provides more predictable variation in specimen processing.

Exposure of hospital personnel to Brucella melitensis and occurrence of laboratory-acquired disease in an endemic area

In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.

Variability of laboratory test results

Variabilities of serum total cholesterol and potassium results provided to 11 medical clinics were assessed using an audit sample-split specimen design. This involved collection of 3 tubes of blood from each of 302 patients, with 1 split specimen divided into 3 audit samples: 1 was sent to the original participating laboratory, another to a commercial referral laboratory, and the third to an academic referee laboratory. Two methods were used to assess variability of test results. Method 1 was based on result pairs corresponding to the split specimen and its corresponding audit sample. Method 2 was based on audit sample results only. The 2 methods provided comparable results for total cholesterol; the estimated coefficient of variation was 1.0% to 3.7%. However, method 1 consistently provided higher estimates of variability for potassium; the estimated SD was 0.096 to 0.168 mmol/L for method 1, while it was 0.035 to 0.090 mmol/L for method 2. Method 1 is more practical, but method 2 can provide a more accurate assessment of analytic variability.

Routine detection and quantification of hepatitis B virus DNA in clinical laboratories: performance of three commercial assays

The detection and quantification of hepatitis B virus (HBV) genomes in molecular biology-based assays appear to be the most reliable methods for monitoring HBV infection and assessing responses to antiviral treatment. The aim of this study was to evaluate the performance of three HBV-DNA detection and quantification assays currently used for the management of HBV-infected patients: a solution-hybridization assay based on hybrid-capture (Digene Hybrid-Capture, Murex Diagnostics, Dartford, UK); a signal-amplification assay based on 'branched-DNA' (bDNA) technology (Quantiplex HBV DNA, Bayer Diagnostics, Emeryville, CA); and a target-amplification assay based on competitive polymerase chain reaction (Amplicor HBV Monitor, Roche Molecular Systems, Pleasanton, CA). The Monitor assay was significantly more sensitive than both the hybrid-capture and bDNA methods. This better sensitivity appeared to be clinically relevant. The linear ranges of quantification in the hybrid-capture, bDNA and Monitor methods were 6.5-9 log10 genome copies/ml, 6.5-9.5 log10 genome equivalents/ml, and 3-5.5 log10 genome copies/ml, respectively. However, the HBV-DNA units used in the three assays were not comparable. The specificity of the hybrid-capture, bDNA and Monitor assays was 99.2% (95% confidence interval: 97.7-100.0%), 99.2% (97.7-100.0%), and 97.8% (95.3-100%), respectively. Their within-run coefficients of variation and log10 SDs were 5.5% (+/- 0.025 log10 copies/ml), 6.7% (+/- 0.029 log10 Eq/ml) and 21.0% (+/- 0.093 log10 copies/ml), respectively. Between-run coefficients of variation ranged from 4.4-39.1%, 5-39.5%, and 17.8-96.1%, respectively. The competitive PCR-based Monitor assay appears to be significantly more sensitive but slightly less specific and reproducible than the hybrid-capture and bDNA methods. Given their respective performance, these three assays should be used in complementary fashion in the management of HBV-infected patients.

Point-of-care testing

In the recent issue of CCLM a paper has been published on the view of the German Working Group on Point-of-Care Testing (POCT) (1). The issue of POCT is extremely important and rightly the authors stress the responsibility of the head of the laboratory. However, they omit to refer to two important documents relating to POCT from the European Communities Confederation of Clinical Chemistry (EC4): one on the essential criteria for quality systems of medical laboratories (2) and another on the additional essential criteria for quality systems of medical laboratories (3), the latter addressing in particular POCT. Both of these documents strongly influence new ISO documents on quality management in medical laboratories. The section of the German Working Group's paper on organizational prerequisites for the establishment of POCT in a hospital could particularly benefit from these references.

Reduction of intra- and interlaboratory variation in CD34+ stem cell enumeration using stable test material, standard protocols and targeted training. DK34 Task Force of the European Working Group of Clinical Cell Analysis (EWGCCA)

The European Working Group on Clinical Cell Analysis (EWGCCA) has, in preparation for a multicentre peripheral blood stem cell clinical trial, developed a single-platform flow cytometric protocol for the enumeration of CD34+ stem cells. Using this protocol, stabilized blood and targeted training, the EWGCCA have attempted to standardize CD34+ stem cell enumeration across 24 clinical sites. Results were directly compared with participants in the UK National External Quality Assessment Scheme (NEQAS) for CD34+ Stem Cell Quantification that analysed the same specimens using non-standardized methods. Two bead-counting systems, Flow-Count and TruCount, were also evaluated by the EWGCCA participants during trials 2 and 3. Using Flow-Count, the intralaboratory coefficient of variation (CV) was </= 5% in 39% of the laboratories (trial 1), increasing to 65% by trial 3. Interlaboratory variation was reduced from 23.3% (trial 1) to 10.8% in trial 3. In trial 2, 70% of laboratories achieved an intralaboratory CV </= 5% using TruCount, increasing to 74% for trial 3; the interlaboratory CV was reduced from 23.4% to 9.5%. Comparative analysis of the EWGCCA and the UK NEQAS cohorts revealed that EWGCCA laboratories, using the standardized approach, had lower interlaboratory variation. Thus, the use of a common standardized protocol and targeted training significantly reduced intra- and interlaboratory CD34+ cell count variation.