Field termination of resuscitation: analysis of a newly implemented protocol.

INTRODUCTION: Earlier work has shown the safety of termination-of-resuscitation (TOR) protocols for traumatic and nontraumatic out-of-hospital cardiac arrest (OOHCA). This study examined the implementation of these protocols in one urban/suburban EMS system. The objective was to determine how often patients are transported to the ED despite meeting TOR criteria. METHODS: All adult OOHCA patients transported to two EDs during a 3.5-year interval were retrospectively identified through dispatch and hospital records. EMS and ED records were evaluated to assess for the presence of TOR protocol criteria and to determine whether the patients should have been transported or pronounced dead on scene. Records were also examined for documentation of mitigating circumstances that might have prompted transport despite meeting TOR criteria. RESULTS: 865 OOHCA patients were identified; 235 met study criteria. Of these, 131 (56%) met TOR criteria but were transported anyway. All expired in the ED or in the hospital (131/131 = 100%, 95% CI: 97.7-100) Of the 43 traumatic OOHCA patients, 27 (63%) met TOR criteria, yet were transported, and all expired in the ED (27/27 = 100%, 95% CI: 89.5-100). Of the 192 nontraumatic OOHCA patients, 104 (54%) met TOR criteria, yet were transported, and all expired in the ED or in the hospital (104/104 = 100%, 95% CI: 97.2-100). In no case was a mitigating circumstance documented to justify transporting a patient meeting TOR criteria. CONCLUSIONS: Termination-of-resuscitation protocols are not being implemented as intended in this EMS system: more than half of cardiac arrest patients meeting criteria for termination of resuscitation were transported anyway. These protocol violations result in emergency transport to the ED for a substantial number of patients for whom continued resuscitative efforts are futile: no patient who met TOR criteria in this sample survived to discharge.

Virologic therapy response significantly correlates with the number of active drugs as evaluated using a LiPA HIV-1 resistance scoring system.

BACKGROUND: Resistance testing is increasingly accepted as a tool in guiding the selection of human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy in HIV-1 infected individuals who fail their current regimen. OBJECTIVES: To descriptively compare the correlation between virologic treatment response and results using three genotypic HIV-1 drug resistance interpretation systems: the VERSANT HIV-1 Resistance Assay (LiPA) system and two sequence-based interpretation systems. STUDY DESIGN: Specimens from 213 HIV-1-infected subjects, either starting (n=104) or switching to (n=109) a regimen of three or four antiretroviral drugs, were collected retrospectively at baseline and after 3 months of uninterrupted therapy. The correlation between viral load change and the number of predicted active drugs in the treatment regimen was assessed. An interpretation algorithm was recently developed to process VERSANT HIV-1 Resistance Assay (LiPA) data. The number of active drugs predicted using this algorithm was rank correlated with the viral load change over a 3-month treatment period. For comparison, a similar calculation was made using two sequence-based algorithms (REGA version 5.5 and VGI GuideLines Rules 4.0), both applied on the same sequences. RESULTS: Statistically significant (p<0.05) correlation coefficients for each of the three HIV-1 drug resistance interpretation systems were observed in the treatment-experienced subjects on a 3-drug regimen (-0.39, -0.38, and -0.42, respectively) as well as on a 4-drug regimen (-0.33, -0.31, and -0.37, respectively). However, no significant correlation was observed in treatment-naive subjects, probably due to the very low frequency of drug resistance in these subjects. CONCLUSION: All three genotypic drug resistance interpretation systems (LiPA version 1, REGA version 5.5, and VGI GuideLines Rules 4.0) were statistically significantly correlated with virologic therapy response as measured by viral load testing.

Hepatitis C virus RNA tests: performance attributes and their impact on clinical utility.

The diagnostic market is driven by the burden of disease in the population and the ease or difficulty of disease diagnosis. The efficacy of available therapeutics determines the need for monitoring. Hepatitis C virus currently affects approximately 3% of the world's population, although the overall response rate to the best available therapies is 56%. Research regarding hepatitis C virus remains elusive due to lack of an efficient cell culture system. Diagnosis and monitoring of active hepatitis C virus infection therefore rely on sophisticated molecular tests. This review will focus on current molecular tests for hepatitis C virus RNA and the performance attributes that these tests require for accurate diagnosis and monitoring of infection.

Multicenter evaluation of the VERSANT HCV RNA qualitative assay for detection of hepatitis C virus RNA.

We report the results of a multicenter evaluation of a new assay for the detection of hepatitis C virus (HCV) RNA in human serum or plasma based on transcription-mediated amplification (HCV TMA). Analysis of combined data obtained from 15 independent sites, including 4 sites in the United States and 11 in Europe, by using preproduction kits showed a limit of detection of 9.8 IU/ml and an overall mean specificity of 97.9%. In addition, assay runs and samples were valid consistently (97.8% of assay runs and 98.0% of specimen results). Of the 15 sites that participated in the multicenter evaluation, 2 subsequently carried out additional performance studies with production kits in support of the assay's registration in France. Comparison of the findings from these two sites during the multicenter evaluation and during the registration studies showed an overall improvement in assay performance. A statistically significant (P < 0.001) improvement was achieved for both specificity and specimen validity in the registration studies, which were 99.4 and 98.1%, respectively. Combined data from the two sites showed a lower limit of detection of approximately 2.4 IU/ml and an improved assay validity of 100%, although the sample size was too small to show statistical significance at the 0.05 level. In summary, the performance characteristics of HCV TMA indicate that this assay is a reliable tool for the detection of HCV RNA in serum or plasma. Improvement in assay performance has been demonstrated with refinement of assay reagents, instrumentation, and operator experience.

Qualitative detection of hepatitis C virus RNA: comparison of analytical sensitivity, clinical performance, and workflow of the Cobas Amplicor HCV test version 2.0 and the HCV RNA transcription-mediated amplification qualitative assay.

The qualitative Cobas Amplicor hepatitis C virus (HCV) version 2.0 assay (HCV PCR) and the Bayer Reference Testing Laboratory HCV RNA transcription-mediated amplification assay (HCV TMA) were compared for analytical sensitivity, clinical performance, and workflow. Limits of detection were determined by testing dilutions of the World Health Organization HCV standard in replicates of 15 at concentrations of from 1.0 to 70 IU/ml. The limit of detection of the HCV PCR assay was calculated to be 45 IU/ml on initial testing and 32 IU/ml after resolution of gray zone results. The calculated limit of detection for HCV TMA was 6 IU/ml. To compare clinical performance, 300 specimens, grouped as follows, were evaluated: 112 samples that were indeterminate in an anti-HCV enzyme immunoassay (EIA) and for which HCV RNA was not detected by HCV PCR; 79 samples that were EIA positive and for which HCV RNA was not detected by HCV PCR; and 105 samples that were both EIA and HCV PCR positive. For these groups, interassay concordance ranged from 96.2% to 100%. In addition, three HCV PCR gray zone specimens and one neonatal specimen were also evaluated. A 64-sample run (full run, 91 specimens) required 5 h for testing by HCV TMA, whereas almost 8 h were required to test a full run of 22 specimens by HCV PCR. HCV TMA demonstrated excellent concordance with HCV PCR when clinical samples were tested. However, HCV TMA was more sensitive than HCV PCR, required less time for test result completion, and had a greater throughput.

Evaluation of the core antigen assay as a second-line supplemental test for diagnosis of active hepatitis C virus infection.

The British Columbia Center for Disease Control laboratory performs approximately 95% of all hepatitis C virus (HCV) antibody tests for the province's 4 million inhabitants. In 2002, the laboratory tested 96,000 specimens for anti-HCV antibodies, of which 4,800 (5%) were seroreactive and required confirmation of active infection. Although HCV RNA assays with a sensitivity of 50 IU/ml or less are recommended for the confirmation of active HCV infection, given the large number of seroreactive specimens tested annually, we evaluated the Ortho trak-C assay (OTCA) as a second-line confirmatory test and determined its limit of detection (LoD). Of 502 specimens from treatment-naïve anti-HCV-positive individuals, 478 had sufficient volumes for evaluation by the OTCA and HCV RNA tests. Core antigen was not detected in 147 of 478 (30.8%) of these specimens, of which 37 of 147 (25.2%) were shown to be viremic by the VERSANT HCV (version 3.0) (branched-DNA) assay and/or the VERSANT HCV qualitative assay. Testing of 144 replicates of a World Health Organization standard dilution series indicated that the LoD of OTCA was approximately 27,000 IU/ml. This LoD is consistent with the inability of OTCA to detect core antigen in clinical specimens with low viral loads. We conclude that OTCA has limited value as a confirmatory test for the diagnosis of active HCV infection because 37 of 367 (10%) of viremic specimens had undetectable core antigen. Qualitative HCV RNA testing remains the present standard for the confirmation of active HCV infection in the diagnostic setting.

Infliximab (REMICADE) therapy in the treatment of pediatric Crohn's disease.

OBJECTIVE: The aim of this study was to assess the efficacy and safety of a single infusion of infliximab in the treatment of pediatric Crohn's disease (CD). METHODS: A total of 21 pediatric CD patients were enrolled at seven study centers and randomized to receive a single infusion of infliximab 1 mg/kg (n = 6), 5 mg/kg (n = 7), or 10 mg/kg (n = 8) over at least 2 hrs at week 0 in this multicenter, open-label, dose-blinded trial. Efficacy assessments, including the Pediatric Crohn's Disease Activity Index (PCDAI), modified CDAI, C-reactive protein concentration (CRP), and erythrocyte sedimentation rate (ESR) determinations, were made at screening and at weeks 1, 2, 4, 8, and 12. Adverse events were assessed throughout study participation. RESULTS: Improvements in the PCDAI, modified CDAI, ESR, and CRP were observed with all infliximab doses, beginning at week 1. On average, all treated patients experienced approximately 50% improvement in the PCDAI by week 2. By week 12, the PCDAI remained approximately 30% improved from baseline. During the study, all 21 patients (100%) achieved a clinical response, and 10 patients (48%) achieved clinical remission. There were no infusion reactions in any of the treatment arms. CONCLUSIONS: The results of this trial suggest that infliximab may be safe and effective as short-term therapy of medically refractory moderate to severe CD in a pediatric population.