Abstract TP292: Impact of Structured Feedback on Emergency Department Physician Culture to Reduce Door-to-Telestroke Activation Times

Introduction: Emergency Department (ED) Physicians typically consult with a specialist after pertinent results are gathered. In the case of acute stroke, delays in neurologist consultation equate to valuable time lost for treatment. When Telestroke went live in June 2015 at our 148-bed regional medical center, the physician norm was challenged because Telestroke protocol stipulates activation of the system before the CT scan. Despite education about the importance of calling early, ED physicians continued to activate Telestroke after gathering results.

Hypothesis: Implementation of timely, structured feedback to ED physicians will change ED physician culture to reduce Door-to-Telestroke Activation (DTA) times.

Methods: In February 2017, monthly feedback was initiated with ED physicians. Graphs showing current performance related to activation times were discussed, goals were reviewed, small improvements were acknowledged, and physicians were encouraged to share their successes. Using a prospective observational study design and a REDCap database, data from June 2015 to February 2017 were compared to data from March 2017 to July 2018.

Results: From June 10, 2015 to July 18, 2018 Telestroke was activated 246 times in the ED. After the feedback initiation, the median DTA of 20 m (n=145) was significantly lower than the baseline median of 32 m (n=101, p<0.0001) and the percentage of activations prior to the CT scan rose significantly from 20% to 46% (p=0.0003). Also, Door-to-Needle (DTN) time decreased to a median of 48 m (n=27), compared to the baseline of 56 m (n=19, p=0.15) and the percentage of ischemic stroke patients treated with IV Alteplase increased to 17.7% from 13.4%. Median Door-to-CT (DTCT) remained unchanged at 17 m both pre and post intervention, demonstrating consistent ED processes.

Conclusions: Timely ED physician feedback led to faster Door-to-Telestroke Activation times. While statistically insignificant, post intervention DTN times rose from a baseline of 63% (n=19) to 81% (n=27, p=0.29) which met the primary Target: Stroke Phase II goal to treat 75% of patients within 60 minutes. Faster activation resulted in faster treatment and ultimately improved chances of a better outcome.

Abstract WP365: Utility of Hyperdense Middle Cerebral Artery Sign for Earlier Activation of Endovascular Team

Introduction: The hyperdense MCA sign has been used as a marker of an underlying large vessel occlusion (LVO)/thrombus in the non-contrast head CT of acute stroke patients. However, due its low sensitivity, it has not been used routinely for definitive diagnosis of LVO. Furthermore, clinicians also have the ability to obtain further imaging with CT angiography to better visualize the vessels in most patients. However, this further imaging can take on average up to an additional 30 minutes due to delays in acquisition, patient cooperation, processing and image transmission time. We wanted to look for a simple sign on the early imaging (non-contrast HCT) to determine if we could activate the neuro interventional suite faster.

Hypothesis: When present, the hyperdense MCA sign can accurately predict presence of a LVO and identify patients eligible for endovascular therapy sooner than vessel imaging.

Methods: We retrospectively looked at all initial non-contrast head CTs for all consecutive stroke patients presenting to our facility in 2017 (n=86), with a last known well time (LKW) < 6 hours and NIHSS > 4, for the presence of a hyperdense MCA sign. We then reviewed subsequent imaging (CTA) to determine if LVO was actually present.

Results: The hyperdense MCA sign was present in 17 (out of 86) cases, all of which had an LVO on CTA. The positive predictive value (PPV) was 100% indicating that there was a high probability that subjects with a positive hyperdense MCA sign will have a LVO. There were 12 cases with an LVO on CTA did not have a hyperdense MCA sign showing a sensitivity of 58.6%, thus the absence of a hyperdense MCA sign does not exclude LVO.

Conclusion: Quick delivery of appropriate treatments for acute stroke patients have been linked to better outcomes. Given our analysis of cases with NIHSS > 4 and LKW < 6 hours, it seems that presence of a hyperdense MCA sign on the initial non-contrast HCT leads to a high level of certainty that an LVO is present. Perhaps this sign, in combination of LKW and NIHSS, can be used to activate the neuro interventional team while additional imaging is being obtained.

Ethnic Differences in Autoantibody Diversity and Hierarchy: More Clues from a US Cohort of Patients with Systemic Sclerosis

OBJECTIVE

To determine the autoantibody repertoire and clinical associations in a multiethnic cohort of American patients with systemic sclerosis (SSc).

METHODS

There were 1000 patients with SSc (196 Hispanic, 228 African American, 555 white, and 21 other) who were screened for antinuclear antibodies (ANA), including anticentromere antibodies (ACA) by indirect immunofluorescence assay, antitopoisomerase-1 (topo-1/Scl-70) by immunodiffusion, and anti-RNA polymerase III (RNAP III) by ELISA. Sera from 160 patients with mainly nucleolar and/or speckled ANA pattern, but negative for ACA, Scl-70, and RNAP III, were further characterized by immunoprecipitation for SSc-specific antibodies.

RESULTS

The prevalence of antibodies against RNAP III, Th/To, and PM/Scl did not differ significantly among the ethnic groups. The frequency of anti-Scl-70 was lowest in whites (18.0%) compared with 24.0% and 26.8% in Hispanics and African Americans (p = 0.01), respectively. Compared with African American patients, Hispanic and white subjects had a higher frequency of ACA (p < 0.0001) and lower frequency of U3-RNP (p < 0.0001). U3-RNP antibodies were uniquely higher in African American patients, independent of clinical subset, while Th/To autoantibodies were associated with limited cutaneous SSc in white subjects. Overall, Hispanic and African American patients had an earlier age of onset and a predominance of diffuse cutaneous SSc compared with their white counterparts.

CONCLUSION

SSc-specific antibodies may predict disease subset; however, the hierarchy of their prevalence differs across ethnic groups. This study provides the most extensive analysis to date on the relevance of autoantibodies in the diagnosis and clinical manifestations of SSc in Hispanic American patients.

Performance Characteristics of Commercial Immunoassays for the Detection of IgG and IgM Antibodies to β2 Glycoprotein I and an Initial Assessment of Newly Developed Reference Materials for Assay Calibration

OBJECTIVES

To investigate the performance characteristics and impact of newly developed reference calibrators on the commutability between anti-β2 glycoprotein I (anti-β2 GPI) immunoassays in antiphospholipid syndrome (APS) and/or systemic lupus erythematosus (SLE).

METHODS

Immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-β2 GPI immunoassays from four manufacturers were evaluated. Serum samples from 269 patients (APS only, n = 31; SLE and APS, n = 83; SLE only, n = 129; pregnancy-related clinical manifestations without APS, n = 26) and 162 women with histories of successful pregnancies were tested. Results were expressed in kit-specific arbitrary units and in the calibrator reference units (RUs) based on 99th percentile cutoff values. Diagnostic accuracies, correlation between kits, and specific clinical manifestations in APS were investigated.

RESULTS

The sensitivities of the assays ranged from 15.8% to 27.2% (IgG) and 12.3% to 15.8% (IgM) while specificities ranged from 79.4% to 86.5% (IgG) and 80.6% to 84.5% (IgM). There was moderate to almost perfect interassay reliability (Cohen κ, 0.69-0.98), and Spearman correlation coefficients were generally improved when results of the IgG determinations were expressed in RUs.

CONCLUSIONS

Although qualitative agreements between immunoassays for both antibody isotypes are acceptable, correlations with APS clinical manifestations were kit dependent. Only the use of IgG reference material improved quantitative correlations between assays.

Cervical Cytology Specimen Stability in Surepath Preservative and Analytical Sensitivity for HPV Testing with the cobas and Hybrid Capture 2 Tests

None of the commercial HPV tests are U.S. FDA-approved for testing of cervical cytology specimens in SurePath preservative. Still, ~30% of HPV testing is performed on specimens in this formalin-containing preservative. Formalin-induced DNA fragmentation and cross-linking may interfere with HPV detection. We evaluated analytical sensitivity and specimen stability of the cobas 4800 HPV (Roche) and Hybrid Capture 2 HPV (HC2, Qiagen) tests with residual cervical cytology samples in SurePath preservative available within 1 week of collection. Cobas testing was performed with and without heating samples at 120°C for 20 min diluted 1:1 in an alkaline environment (pretreatment) to revert DNA crosslinking. Stability was tested after 2 weeks of storage at ambient temperature followed by ≤10 weeks at 4°C. Analytical sensitivity and positivity rates (HC2, 18%; cobas pretreated, 46%; cobas untreated, 47%) were greater for cobas than HC2 (n = 682). After 6 weeks of storage, mean HC2 ratios were lower (mean 0.9, SD 6.3) but high variability limited statistical power to detect trends. Cobas threshold cycles (Ct's) increased in untreated (mean 2.1) but not pretreated samples (mean 0.3; n = 110; p≤0.0001). Overall, cobas had greater analytical sensitivity for samples in SurePath preservative. Although pretreatment introduced a manual sample transfer step and 30 min of incubation times, it improved stability without negatively affecting analytical sensitivity. While awaiting results of large trials to evaluate the clinical performance of cobas, the addition of the pretreatment step may improve the detection of HPV, especially after prolonged sample storage.

Abstract TP339: Operations Director, Neurosciences Clinical Program, Intermountain Healthcare

Introduction: Beginning January 2014, a 245-bed Intermountain Healthcare primary stroke center was using a private Telestroke (SOC) service. On April 1, 2015, Intermountain implemented its own centralized, internal Telestroke service to provide coverage at this primary stroke center and five other hospitals. The Intermountain Telestroke service uses an internal telemedicine platform with employed physicians providing coverage. To clarify, the Intermountain system has a physician answer calls directly; the SOC model uses an intermediary before connecting to the physician.

Hypothesis: Implementation of a centralized, internal Telestroke service will result in improved physician response and improved time to treatment compared to the private service.

Methods: The Intermountain Healthcare enterprise data warehouse and SOC summary reports provided the data for this analysis. Wilcoxon-Mann-Whitney test was used to compare physician response time, DTN time, and door to CT time in patients treated during the 15-month SOC era to patients treated by the in house telestroke service.

Results: From Jan 2014-Mar 2015, 27 patients received IV TPA at the facility, but only 2/27 had door to needle (DTN) time of <60m. The median DTN time in 2014 was 84 min and the median door to CT time was 18 min, strongly suggesting that the neurologist response time of this service was too long to meet AHA standards. Since implementing the Intermountain service, there has been a statistically significant improvement in DTN time. During the SOC time period, the median DTN time was 92.5 min (N = 35). After implementation, the Intermountain service provided a significantly lower median DTN time of 62.5 min (N=4; p = 0.03). The SOC median technician call-back time was 9.2 min (N=85), with an average physician video response time of 32 min (N=79). Intermountain median physician response time is 4 min (N=91). The door to CT time was not significantly different (Jan 2014-March 2015 was 18 min. vs Mar-May 2015, 14 min, N=31).

Conclusions: The Intermountain Telestroke service outperformed SOC in response time and times to treatment. For healthcare systems that have the resources and expertise, an internal Telestroke service may result in faster times to treatment and better patient outcomes.

The use of circulating donor specific antibody to predict biopsy diagnosis of antibody-mediated rejection and to provide prognostic value after heart transplantation in children

BACKGROUND

Antibody-mediated rejection (AMR) is a significant cause of mortality after heart transplantation (HT). Although the presence of donor specific antibody (DSA) is a risk factor for developing AMR, serial DSA testing is not widely performed. We aimed to investigate the predictive values and prognostic implications of circulating DSA using endomyocardial biopsy as the gold standard for AMR diagnosis in pediatric recipients of HT.

METHODS

We performed a retrospective study in pediatric recipients of HT followed during the period 2009-2013 with at least 1 biopsy paired with DSA testing. Positive DSA was defined at mean fluorescent intensity (MFI) ≥2,000 using single antigen bead testing. Statistical analyses included 2 × 2 contingency tables, receiver operating characteristic analysis for optimal MFI cutoffs, Spearman correlation of MFI strength to AMR grade, and Kaplan-Meier analysis of event-free survival.

RESULTS

Of 66 children included, 27 (41%) had ≥1 DSA positive test. DSA testing had a sensitivity of 92.6%, specificity of 62.2%, positive predictive value of 24.0%, and negative predictive value of 98.5% for biopsy diagnosis of AMR at our institution. There was a statistically significant correlation between higher MFI and higher AMR grade. Patients with positive DSA and AMR had similar survival early after DSA detection but trended toward lower cardiovascular event-free survival later compared with patients without DSA and a negative biopsy.

CONCLUSIONS

The results of DSA testing in this cohort showed excellent sensitivity and negative predictive value for biopsy-diagnosed AMR, suggesting that DSA testing may aid in the non-invasive prediction of AMR absence in HT. The correlation of DSA MFI strength with higher AMR biopsy grade and the trend toward differences in longer term cardiovascular outcomes provide evidence for routine DSA monitoring after pediatric HT.

Laboratory evaluation of anti-phospholipid syndrome: a preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at-risk patient cohort

Immunoglobulin (Ig)G/IgM autoantibodies to phosphatidylserine/prothrombin (aPS/PT) were evaluated individually and in combination with criteria anti-phospholipid (aPL) tests in a prospectively ascertained cohort of patients at risk for anti-phospholipid syndrome (APS). One hundred and sixty (160) consecutive requests for lupus anti-coagulant (LAC) from the University of Utah Health Sciences Center were identified during 8 weeks. Of these, 104 unique patients had additional requests for cardiolipin (aCL) and/or beta2 glycoprotein I (aβ2 GPI) IgG and/or IgM; samples were retained and analysed for aPS/PT, aCL and/or aβ2 GPI IgG and IgM antibodies. Following testing, a comprehensive chart review was performed and patients categorized according to their clinical diagnosis. Individual and combined sensitivities, specificities, odd ratios (OR), diagnostic accuracy for specific tests or combinations by receiver operating characteristic (ROC), area under the curve (AUC) analyses and correlations between test results were determined. The sensitivities of aPS/PT IgG/IgM (54·6/45·5%) were lower than LAC (81·8%) but higher relative to aCL IgG/IgM (27·3/0%) or aβ2 GPI IgG/IgM (27·3/0%). The best correlation between LAC and any aPL test was observed with aPS/PT (P = 0·002). There was no significant difference in the diagnostic accuracies for any panel with LAC: LAC/aβ2 GPI IgG/aCL IgG [AUC 0·979, OR 475·4, 95% confidence interval (CI) 23·1-9056·5, P = 0·0001 and LAC/aβ2 GPI IgG/aPS/PT IgG or LAC/aPS/PT IgG/aCL IgG (AUC 0·962, OR 265·3, 14·2-4958·2, P = 0·0001). The high correlation between LAC and aPS/PT IgG/IgM in this preliminary study suggest that this marker may be useful in the evaluation of APS. More studies to determine the optimal aPL antibody tests combination are needed.

Online information resources of toxicology in Sweden

This article presents toxicological information resources in Sweden available to the public on the Internet. The main focus is on websites of organizations and universities with toxicological information in English. For example, the National Chemicals Inspectorate (KemI) has several databases with information on chemical substances on their website as well as regulatory information about chemicals. The Swedish Environmental Protection Agency has a database containing environmental information and on the website of the National Institute of Working Life a database on occupational health is available. An important part of toxicological research is carried out at the Institute of Environmental Medicine at the Karolinska Institute. Several universities and colleges are responsible for research, education and training in toxicology and ecotoxicology.

The distribution of total and specific serum IgE in the European Community Respiratory Health Survey

BACKGROUND

Variations in the prevalence of atopy could provide important clues to the etiology of atopy and asthma. Although estimates of prevalence are available from different studies, a lack of standardization makes comparisons difficult.

OBJECTIVE

This study was conducted to estimate the variation of geometric mean levels of serum IgE and the prevalence of specific IgE to common allergens between populations as part of the European Community Respiratory Health Survey (ECRHS), a multicenter survey of asthma and risk factors for asthma.

METHODS

Random samples of subjects living in 37 centers in 16 countries who had answered a questionnaire about their respiratory symptoms were invited for further assessment including total serum IgE and the presence of specific IgE against house dust mite (Dermatophagoides pteronyssinus), timothy grass, cat, Cladosporium herbarum, and a local allergen. Sera were tested from 13,883 persons.

RESULTS

The estimated prevalence of atopy, defined as the presence of at least one positive specific IgE, ranged from 16% in Albacete (Spain) to 45% in Christchurch (New Zealand). The geometric mean total serum IgE varied from 13 kU/L in Reykjavik (Iceland) to 62 kU/L in Bordeaux (France). There was no relation between the geometric mean total serum IgE in a center and the prevalence of atopy.

CONCLUSIONS

There are substantial variations in the prevalence of atopy and the level of serum IgE. These variations are independent of each other and likely to be largely environmental in origin.

Microorganisms on toothbrushes at day-care centers

The microflora on 44 toothbrushes at 4 day-care centers in the city of Göteborg have been investigated as a presumptive risk factor for transmission of microorganisms by children. Non-supervised toothbrushing without the use of toothpaste was performed at the day-care centers twice a day. Streptococci, predominantly S. salivarius, S. sanguis, and S. mitis, were the most frequently recorded group of microorganisms and generally constituted the greatest part of the flora (on average, 50%). Beta-hemolytic streptococci were not found in any sample. Haemophilus species were noted in 82% of the samples. H. parainfluenzae being the most frequent, and H. influenzae being identified in only one sample. Anaerobes constituted on average a third of the microflora. Staphylococci were identified in 86% of the samples, S. epidermidis dominating. Fungi including molds were found in 50% of the samples, and from one day-care center large numbers of enteric organisms were identified. Thus this study shows that unsupervised toothbrushing at day-care centers can be questioned, more from a general hygienic point of view than from the risk of transmitting serious pathogens.

Diagnostic capabilities of penicillin-based structures as tools in the in vitro diagnosis of penicillin allergy

Various penicillin-based structures attached to paper disks were used in the radioallergosorbent test (RAST) to measure concentrations of circulating specific IgE antibodies in sera from subjects suspected of having penicillin allergy. The structures used were penicilloyl, penicillanyl, penicoyl and penicanyl groups prepared from benzylpenicillin (PG), phenoxymethylpenicillin (PV), amoxicillin (AX) and 6-amino-penicillanic acid (6-APA). The efficacy of these structures was evaluated using serum samples from 53 subjects who, on clinical grounds, were considered to have had adverse reactions to penicillins. The results showed the presence of IgE antibodies specific to the penicillin side-chain in certain patients, whereas others had IgE antibodies specific to the penicilloyl or penicillin basic structure (penicillin nucleus), which led to clinical cross-reactions between penicillins. The results showed that the use of several penicillin-based structures in a new test system increased the positive rate observed to 54.7% from 37.7% utilizing penicilloyl G, penicilloyl V and amoxicilloyl Phadebas RAST. Thus, the prepared species improve the capabilities of the in vitro diagnosis of penicillin allergy.

Ligature wires and elastomeric rings: two methods of ligation, and their association with microbial colonization of Streptococcus mutans and lactobacilli

Twelve orthodontic patients undergoing treatment with fixed appliances took part in the present study. In all patients elastomeric rings were used for ligation on one side of the dental arch midline, whereas steel wires were used on the opposite side. The number of micro-organisms in samples of plaque, taken from the labial surface of the upper lateral incisors, was recorded on five occasions during treatment. In samples of saliva, the numbers of Streptococcus mutans and lactobacilli were recorded on the same occasions. This registration was also made on two occasions before insertion of the fixed appliance, and 6 weeks after the period of active treatment. The results showed that, in the majority of patients, the incisor which was attached to the arch-wire with an elastomeric ring, exhibited a greater number of micro-organisms in the plaque than the incisor ligated with steel wire. Following insertion of fixed appliances the number of S. mutans and lactobacilli in saliva increased significantly. Variations in the number of micro-organisms in the saliva during active treatment were not reflected in any relative increase or decrease in microbial colonization on either steel ligatures or elastomeric rings. The use of retainers after active treatment was not associated with increased numbers of micro-organisms in the saliva.

Clinical and immunological characteristics of Brazil nut allergy

Twelve cases of allergy to Brazil nut have been recorded in the last 8 years. The reaction is usually IgE mediated and most patients have other atopic diseases. There appear to be several proteins with potent antigenic components in Brazil nut.