Use of Routine Complete Blood Count Results to Rule Out Anaplasmosis Without the Need for Specific Diagnostic Testing.

BACKGROUND: Anaplasmosis presents with fever, headache, and laboratory abnormalities including leukopenia and thrombocytopenia. Polymerase chain reaction (PCR) is the preferred diagnostic but is overutilized. We determined if routine laboratory tests could exclude anaplasmosis, improving PCR utilization. METHODS: Anaplasma PCR results from a 3-year period, with associated complete blood count (CBC) and liver function test results, were retrospectively reviewed. PCR rejection criteria, based on white blood cell (WBC) and platelet (PLT) counts, were developed and prospectively applied in a mock stewardship program. If rejection criteria were met, a committee mock-refused PCR unless the patient was clinically unstable or immunocompromised. RESULTS: WBC and PLT counts were the most actionable routine tests for excluding anaplasmosis. Retrospective review demonstrated that rejection criteria of WBC ≥11 000 cells/µL or PLT ≥300 000 cells/µL would have led to PCR refusal in 428 of 1685 true-negative cases (25%) and 3 of 66 true-positive cases (5%) involving clinically unstable or immunocompromised patients. In the prospective phase, 155 of 663 PCR requests (23%) met rejection criteria and were reviewed by committee, which endorsed refusal in 110 of 155 cases (71%) and approval in 45 (29%), based on clinical criteria. PCR was negative in all 45 committee-approved cases. Only 1 of 110 mock-refused requests yielded a positive PCR result; this patient was already receiving doxycycline at the time of testing. CONCLUSIONS: A CBC-based stewardship algorithm would reduce unnecessary Anaplasma PCR testing, without missing active cases. Although the prospectively evaluated screening approach involved medical record review, this was unnecessary to prevent errors and could be replaced by a rejection comment specifying clinical situations that might warrant overriding the algorithm.

Reference interval evaluation of high-sensitivity troponin T and N-terminal B-type natriuretic peptide in Vietnam and the US: The North South East West Trial.

BACKGROUND: Reference intervals of high-sensitivity troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been determined from Western populations. No data are available regarding expected values in Asian populations. METHODS: A total of 1157 age- and sex-matched healthy individuals (mean age, 41.2 years; 48.0% male) were prospectively enrolled from the US (n = 565) and Vietnam (n = 592). Blood samples were analyzed for hs-cTnT and NT-proBNP. Median values were determined for each country and compared in unadjusted analyses and in analyses adjusted for age, sex, body mass index, study site, race, and vital signs. RESULTS: Median hs-cTnT concentrations were slightly higher for individuals from the US than for those from Vietnam, but both were below the limit of detection (3.7 vs 3.0 ng/L, respectively; P = 0.03). More US participants had an hs-cTnT concentration above the limit of detection (57.2% vs 47.3%; P = 0.001), but the 99th percentile concentration was slightly higher for Asians (US 15.1 vs Vietnam 19.0 ng/L). Concentrations for >98% of both populations were below the standard hs-cTnT 99th percentile of 14.0 ng/L (P = 0.54). Median NT-proBNP concentrations were slightly higher for US participants compared with Vietnamese participants (28 vs 16 ng/L, respectively; P < 0.001). Following adjustment, differences in concentrations of NT-proBNP between healthy US and Vietnamese populations remained significant, whereas for hs-cTnT the differences were no longer significant. Inclusion of hs-cTnT values down to the limit of blank did not change the result. CONCLUSIONS: The differences in hs-cTnT and NT-proBNP between healthy individuals from the US and Vietnam are small. Previously derived reference intervals for both analytes may be applied in Asian populations.

Clinical decision support to improve CBC and differential ordering.

OBJECTIVES: Complete blood count and differential (CBC diff) is a common laboratory test that may be overused or misordered, particularly in an inpatient setting. We assessed the ability of a clinical decision support (CDS) alert to decrease unnecessary orders for CBC diff and analyzed its impact in the laboratory. METHODS: We designed 3 CDS alerts to provide guidance to providers ordering CBC diff on inpatients at frequencies of daily, greater than once daily, or as needed. RESULTS: The 3 alerts were highly effective in reducing orders for CBC diff at the frequencies targeted by the alert. Overall, test volume for CBC diff decreased by 32% (mean of 5257 tests per month) after implementation of the alerts, with a corresponding decrease of 22% in manual differentials performed (mean of 898 per month). Turnaround time for manual differentials decreased by a mean of 41.5 minutes, with a mean decrease of up to 90 minutes during peak morning hours. CONCLUSIONS: The 3 CDS alerts successfully decreased inpatient orders for CBC diff and improved the quality of patient care by decreasing turnaround time for manual differentials.

Glucose meter standardization across a large academic hospital system.

BACKGROUND: To select and standardize point-of-care (POC) glucose meters across a multi-hospital system. METHODS: We formed a multidisciplinary POC glucose standardization working group including key stakeholders from each site. A set of selection criteria: usability, clinical and laboratory performance, indications for use, interface connectivity, ease of implementation and ongoing operational costs were used to develop a scoring schemato facilitate a consensus-driven selection process. RESULTS: Method comparison and consensus error grid evaluation against the clinically validated reference methods demonstrated that the analytical performance for all candidate meters was comparable for both the laboratory and clinical evaluation. However, Meter 1 ranked highest in usability evaluations, implementation and streamlined interface connectivity. The meter selection process and implementation were staggered across sites due to complexity of transitioning to a new manufacturer's meter and limitations in vendor support for training and ongoing troubleshooting of interface connectivity. CONCLUSIONS: Standardization of POC glucose meters in a large multi-hospital system is a complex undertaking requiring robust, multidisciplinary organizational structure both system-wide and locally, development of consensus-driven selection tools, usability evaluation by end-users, laboratory and clinical evaluation of the analytical performance, and a strong vendor-laboratory partnership during the implementation process.

Detection and localization of early- and late-stage cancers using platelet RNA.

Cancer patients benefit from early tumor detection since treatment outcomes are more favorable for less advanced cancers. Platelets are involved in cancer progression and are considered a promising biosource for cancer detection, as they alter their RNA content upon local and systemic cues. We show that tumor-educated platelet (TEP) RNA-based blood tests enable the detection of 18 cancer types. With 99% specificity in asymptomatic controls, thromboSeq correctly detected the presence of cancer in two-thirds of 1,096 blood samples from stage I-IV cancer patients and in half of 352 stage I-III tumors. Symptomatic controls, including inflammatory and cardiovascular diseases, and benign tumors had increased false-positive test results with an average specificity of 78%. Moreover, thromboSeq determined the tumor site of origin in five different tumor types correctly in over 80% of the cancer patients. These results highlight the potential properties of TEP-derived RNA panels to supplement current approaches for blood-based cancer screening.

Clinical uncertainty, diagnostic accuracy, and outcomes in emergency department patients presenting with dyspnea.

BACKGROUND: Dyspnea is a common complaint in the emergency department (ED) and may be a diagnostic challenge. We hypothesized that diagnostic uncertainty in this setting is associated with adverse outcomes, and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) testing would improve diagnostic accuracy and reduce diagnostic uncertainty. METHODS: A total of 592 dyspneic patients were evaluated from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study. Managing physicians were asked to provide estimates from 0% to 100%of the likelihood of acutely destabilized heart failure (ADHF). A certainty estimate of either 20% or lower or 80% or higher was classified as clinical certainty, while estimates between 21% and 79% were defined as clinical uncertainty. Associations between clinical uncertainty,hospital length of stay, morbidity, and mortality were examined. The diagnostic value of clinical judgment vs NT-proBNP measurement was compared across categories of clinical certainty. RESULTS: Clinical uncertainty was present in 185 patients (31%), 103 (56%) of whom had ADHF. Patients judged with clinical uncertainty had longer hospital length of stay and increased morbidity and mortality,especially those with ADHF. Receiver operating characteristic analysis of clinical judgment yielded an area under the curve (AUC) of 0.88 in the clinical certainty group and 0.76 in the uncertainty group (P<.001); NT-proBNP testing alone in these same groups had AUCs of 0.96 and 0.91, respectively. The combination of clinical judgment with NT-proBNP testing yielded improvements in AUC. CONCLUSIONS: Among dyspneic patients in the ED, clinical uncertainty is associated with increased morbidity and mortality, especially in those with ADHF.The addition of NT-proBNP testing to clinical judgment may reduce diagnostic uncertainty in this setting.

Cardiac biomarkers, electrolytes, and other analytes in collapsed marathon runners: implications for the evaluation of runners following competition.

We measured analytes in collapsed Boston Marathon runners to compare with changes in asymptomatic runners. Of collapsed runners at the 2007 marathon, 18.2% had a measurable cardiac troponin T (cTnT) value with a mean postrace level of 0.017 ng/mL (0.017 microg/L; SD, 0.02 ng/mL [0.02 microg/L]). Three subjects had cTnT values above the cutoff (0.10 ng/mL [0.10 microg/L]) typically used for the diagnosis of acute myocardial infarction. The mean and median N-terminal pro-B-type natriuretic peptide levels were 73 ng/L (SD, 77.3 ng/L) and 54.3 ng/L (interquartile range, 22.8-87.3 ng/L), respectively, in collapsed runners. Only 4.9% had values more than the age-specific normal value (<125 ng/L for subjects younger than 75 years). In collapsed subjects at the 2006 marathon, 18.0% had an abnormal sodium value, including 18 cases of hypernatremia and 7 cases of hyponatremia. The ionized calcium level was low in 49% of subjects, and the ionized magnesium level was low in 19.5% and elevated in 1 subject. The blood lactate level was elevated in 95% of subjects. The frequency of elevated postrace cTnT levels in collapsed athletes after endurance exercise is similar to that in asymptomatic runners. Other metabolic abnormalities, including hypernatremia, hyponatremia, low ionized calcium and magnesium levels, and lactic acidosis may contribute to muscle fatigue and collapse.

Analytical and clinical performance of the Ortho-Clinical Diagnostics VITROS amino-terminal pro-B type natriuretic peptide assay.

BACKGROUND: Measurement of amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is useful for evaluating patients with heart failure (HF). METHODS: We evaluated the performance of a new automated NT-proBNP assay. RESULTS: The VITROS NT-proBNP assay had mean within-run and total imprecision of 1.0% and 3.4% at NT-proBNP concentrations from 67-27,500 ng/l. Acceptable linearity, functional/analytical sensitivity were demonstrated. Anticoagulant/tube types had no effect on results. Excellent sample stability and no high-dose hook were observed. High correlation between the VITROS and Elecsys methods was demonstrated (r=0.995; P<.001), with 98.3% clinical concordance. VITROS NT-proBNP concentrations were significantly higher in HF subjects than those without (1210 versus 68 ng/l; P<.001) and associated with HF symptom severity (P<.001). The VITROS assay had AUC for HF of 0.95 (P<.001), and had excellent NPV for excluding HF. CONCLUSIONS: The automated VITROS NT-proBNP assay demonstrates excellent analytical and clinical performance for evaluating the presence and severity of HF.

The effects of transport temperature and time on routine and specialized coagulation assays.

: Coagulation laboratories have largely stopped transporting whole blood specimens on ice, due to adverse effects on factor VIII, von Willebrand factor, and the prothrombin time. However, it is unknown whether ice should be required or avoided for other coagulation assays. Furthermore, the amount of time that specimens remain stable during transportation at room temperature (RT) is also largely unknown for many coagulation tests. Therefore, this study investigated specimen stability on ice and RT for a comprehensive panel of coagulation tests. One tube of whole blood from each volunteer (n = 22) was centrifuged immediately (time 0), one was stored for 4 h on ice, and one was stored for 4 h at RT before centrifugation. Among time 0, 4 h on ice, and 4 h at RT samples, no statistically significant differences were found for fibrinogen, activated protein C resistance, thrombin time, reptilase time, antithrombin activity, chromogenic protein C, factor XII, and antiplasmin activity. Prothrombin time, activated partial thromboplastin time, factors IX, XI, protein S activity, and plasminogen activity showed statistically, but not clinically, significant differences. On ice, the only analytes that showed clinically significant changes (≥6.0% from time 0) were factors VII, VIII, von Willebrand factor antigen, and ristocetin cofactor, which were 14.0% higher, and 19.2, 9.5, and 18.8% lower than time 0, respectively. At RT, all analytes were stable except factor VIII was 9.4% lower than time 0. Only factors II, V, X, and PTT-LA lupus anticoagulant showed a possible slight benefit from ice, but the statistically significant differences were not clinically significant. Ice did not substantially benefit any of the coagulation assays. All tests were stable at RT, except more study is needed regarding factor VIII.

Creation and Use of an Electronic Health Record Reporting Database to Improve a Laboratory Test Utilization Program.

OBJECTIVES: Laboratory-based utilization management programs typically rely primarily on data derived from the laboratory information system to analyze testing volumes for trends and utilization concerns. We wished to examine the ability of an electronic health record (EHR) laboratory orders database to improve a laboratory utilization program. METHODS: We obtained a daily file from our EHR containing data related to laboratory test ordering. We then used an automated process to import this file into a database to facilitate self-service queries and analysis. RESULTS: The EHR laboratory orders database has proven to be an important addition to our utilization management program. We provide three representative examples of how the EHR laboratory orders database has been used to address common utilization issues. We demonstrate that analysis of EHR laboratory orders data has been able to provide unique insights that cannot be obtained by review of laboratory information system data alone. Further, we provide recommendations on key EHR data fields of importance to laboratory utilization efforts. CONCLUSION: We demonstrate that an EHR laboratory orders database may be a useful tool in the monitoring and optimization of laboratory testing. We recommend that health care systems develop and maintain a database of EHR laboratory orders data and integrate this data with their laboratory utilization programs.

Quality Control Practices for Chemistry and Immunochemistry in a Cohort of 21 Large Academic Medical Centers.

OBJECTIVES: In the United States, minimum standards for quality control (QC) are specified in federal law under the Clinical Laboratory Improvement Amendment and its revisions. Beyond meeting this required standard, laboratories have flexibility to determine their overall QC program. METHODS: We surveyed chemistry and immunochemistry QC procedures at 21 clinical laboratories within leading academic medical centers to assess if standardized QC practices exist for chemistry and immunochemistry testing. RESULTS: We observed significant variation and unexpected similarities in practice across laboratories, including QC frequency, cutoffs, number of levels analyzed, and other features. CONCLUSIONS: This variation in practice indicates an opportunity exists to establish an evidence-based approach to QC that can be generalized across institutions.

Myocardial injury and ventricular dysfunction related to training levels among nonelite participants in the Boston marathon.

BACKGROUND: Multiple studies have individually documented cardiac dysfunction and biochemical evidence of cardiac injury after endurance sports; however, convincing associations between the two are lacking. We aimed to determine the associations between the observed transient cardiac dysfunction and biochemical evidence of cardiac injury in amateur participants in endurance sports and to elicit the risk factors for the observed injury and dysfunction. METHODS AND RESULTS: We screened 60 nonelite participants, before and after the 2004 and 2005 Boston Marathons, with echocardiography and serum biomarkers. Echocardiography included conventional measures as well as tissue Doppler-derived strain and strain rate imaging. Biomarkers included cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP). All subjects completed the race. Echocardiographic abnormalities after the race included altered diastolic filling, increased pulmonary pressures and right ventricular dimensions, and decreased right ventricular systolic function. At baseline, all had unmeasurable troponin. After the race, > 60% of participants had increased cTnT > 99th percentile of normal (> 0.01 ng/mL), whereas 40% had a cTnT level at or above the decision limit for acute myocardial necrosis (> or = 0.03 ng/mL). After the race, NT-proBNP concentrations increased from 63 (interquartile range [IQR] 21 to 81) pg/mL to 131 (IQR 82 to 193) pg/mL (P<0.001). The increase in biomarkers correlated with post-race diastolic dysfunction, increased pulmonary pressures, and right ventricular dysfunction (right ventricular mid strain, r=-0.70, P<0.001) and inversely with training mileage (r=-0.71, P<0.001). Compared with athletes training > 45 miles/wk, athletes who trained < or = 35 miles/wk demonstrated increased pulmonary pressures, right ventricular dysfunction (mid strain 16+/-5% versus 25+/-4%, P<0.001), myocyte injury (cTnT 0.09 versus < 0.01 ng/mL, P<0.001), and stress (NT-proBNP 182 versus 106 pg/mL, P<0.001). CONCLUSIONS: Completion of a marathon is associated with correlative biochemical and echocardiographic evidence of cardiac dysfunction and injury, and this risk is increased in those participants with less training.

Medicolegal liability in laboratory medicine.

The laboratory testing process, including the preanalytic, analytic, and postanalytic phases, is an area where errors frequently occur. These errors may impair the diagnostic process and compromise patient safety. Delay in diagnosis and failure to diagnose are common reasons for a medicolegal action. It is estimated that over 70% of medical decisions are made using laboratory data. For this reason, the laboratory is often involved either directly or indirectly in medical liability cases. The laboratory and hospital need to design systems that reduce the possibility of error and to rapidly identify and resolve the errors that do occur. Because the pre- and postanalytic processes extend into the clinical operations of the hospital, the laboratory can play an important role in promoting patient safety by assisting clinicians with test ordering, communicating test results appropriately, and aiding in the interpretation of results.

Analysis of Daily Laboratory Orders at a Large Urban Academic Center: A Multifaceted Approach to Changing Test Ordering Patterns.

OBJECTIVES: We sought to address concerns regarding recurring inpatient laboratory test order practices (daily laboratory tests) through a multifaceted approach to changing ordering patterns. METHODS: We engaged in an interdepartmental collaboration to foster mindful test ordering through clinical policy creation, electronic clinical decision support, and continuous auditing and feedback. RESULTS: Annualized daily order volumes decreased from approximately 25,000 to 10,000 during a 33-month postintervention review. This represented a significant change from preintervention order volumes (95% confidence interval, 0.61-0.64; P < 10-16). Total inpatient test volumes were not affected. CONCLUSIONS: Durable changes to inpatient order practices can be achieved through a collaborative approach to utilization management that includes shared responsibility for establishing clinical guidelines and electronic decision support. Our experience suggests auditing and continued feedback are additional crucial components to changing ordering behavior. Curtailing daily orders alone may not be a sufficient strategy to reduce in-laboratory costs.

Swarm Intelligence-Enhanced Detection of Non-Small-Cell Lung Cancer Using Tumor-Educated Platelets.

Blood-based liquid biopsies, including tumor-educated blood platelets (TEPs), have emerged as promising biomarker sources for non-invasive detection of cancer. Here we demonstrate that particle-swarm optimization (PSO)-enhanced algorithms enable efficient selection of RNA biomarker panels from platelet RNA-sequencing libraries (n = 779). This resulted in accurate TEP-based detection of early- and late-stage non-small-cell lung cancer (n = 518 late-stage validation cohort, accuracy, 88%; AUC, 0.94; 95% CI, 0.92-0.96; p < 0.001; n = 106 early-stage validation cohort, accuracy, 81%; AUC, 0.89; 95% CI, 0.83-0.95; p < 0.001), independent of age of the individuals, smoking habits, whole-blood storage time, and various inflammatory conditions. PSO enabled selection of gene panels to diagnose cancer from TEPs, suggesting that swarm intelligence may also benefit the optimization of diagnostics readout of other liquid biopsy biosources.

Analysis of laboratory critical value reporting at a large academic medical center.

Reporting of laboratory critical values has become an issue of national attention as illustrated by recent guidelines described in the National Patient Safety Goals of the Joint Commission on Accreditation of Healthcare Organizations. Herein, we report the results of an analysis of 37,503 consecutive laboratory critical values at our institution, a large urban academic medical center. We evaluated critical value reporting by test, laboratory specialty, patient type, clinical care area, time of day, and critical value limits. Factors leading to delays in critical value reporting are identified, and we describe approaches to improving this important operational and patient safety issue.

Measurement of a plasma stroke biomarker panel and cardiac troponin T in marathon runners before and after the 2005 Boston marathon.

We report changes in cardiac troponin-T (TnT) and a new plasma stroke biomarker panel (D-dimer, B-natriuretic peptide [BNP], matrix metalloproteinase-9 [MMP-9], S-100 b, Biosite Diagnostics, San Diego, CA) in 30 nonprofessional marathon runners before and immediately after the 2005 Boston Marathon. Following competition, there was a statistically significant increase in MMP-9 (P < .001) and D dimer (P < .001). Nonsignificant changes in S-100 b and BNP were observed. Premarathon and postmarathon values for a multimarker stroke index increased from 0.97 (normal) to 3.5 (low risk or more; P < .001). Two subjects had index values more than the high-risk cutoff value. Mean TnT premarathon and postmarathon levels increased (from <0.01 to 0.03 ng/mL; P < .0001). After the marathon, with a cutoff value of 0.05 ng/mL, 7 runners (23%) had values above the manufacturer's recommended cutoff for myocardial damage. Although biochemical evidence of myocardial damage following strenuous exercise may reflect myocardial stunning or subclinical ischemia, the changes in the stroke index and values for individual stroke markers may reflect a systemic inflammatory response to exertional rhabdomyolysis which is common, but the possibility of subclinical central nervous system damage cannot be excluded.

Decreased inflammation and improved survival with recombinant human activated protein C treatment in experimental acute pancreatitis.

HYPOTHESIS: Drotrecogin alfa (activated), the pharmacologic form of activated protein C and the first Food and Drug Administration-approved drug for treatment of severe sepsis, is beneficial in experimental acute pancreatitis (AP). DESIGN: Animal study. SETTING: Laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Mild (intravenous cerulein) or severe (intravenous cerulein plus intraductal glycodeoxycholic acid) AP was induced in 72 rats, and coagulation evaluated. Rats with severe AP were randomized to treatment with drotrecogin alfa (activated), 100 microg/kg per hour, or isotonic sodium chloride. MAIN OUTCOME MEASURES: Histologic scoring of pancreatic necrosis, inflammation of the pancreas and lung (measured by myeloperoxidase concentration), coagulation measures, and 24-hour survival. RESULTS: Severe consumptive coagulopathy, hemoconcentration, and leukocytosis were observed 6 hours after induction of severe AP, but not in mild AP. Treatment of AP with drotrecogin did not worsen coagulation measures. Although the degree of pancreatic necrosis was comparable in treated and untreated animals with severe AP, drotrecogin significantly reduced myeloperoxidase levels in the pancreas (P = .009) and lungs (P = .03). The 24-hour survival in severe AP was markedly improved in animals treated with drotrecogin (86% vs 38%; P = .05). CONCLUSIONS: Animals with severe AP have severe consumptive coagulopathy, but administration of drotrecogin alfa (activated), 100 microg/kg per hour, does not worsen coagulation abnormalities. Drotrecogin treatment reduces inflammation in the pancreas and lungs and significantly improves survival. These results encourage clinical investigation of drotrecogin in the treatment of severe AP.