An Improved Definition and SAFE Rule for Predicting Difficult Intravascular Access (DIVA) in Hospitalized Adults.

Patients with difficult intravascular access (DIVA) are common, yet the condition is often ignored or poorly managed, leading to patient dissatisfaction and misuse of health care resources. This study sought to assess all published risk factors associated with DIVA in order to promote prospective identification and improved management of patients with DIVA. A systematic literature review on risk factors associated with DIVA was conducted. Risk factors published in ≥4 eligible studies underwent a multivariate meta-analysis of multiple factors (MVMA-MF) using the Bayesian framework. Of 2535 unique publications identified, 20 studies were eligible for review. In total, 82 unique DIVA risk factors were identified, with the 10 factors found in ≥4 studies undergoing MVMA-MF. Significant predictors of DIVA included vein visibility, vein palpability, history of DIVA, obesity (body mass index [BMI] >30), and history of intravenous (IV) drug abuse, which were combined to create the mnemonic guideline, SAFE: See, Ask (about a history of DIVA or IV drug abuse), Feel, and Evaluate BMI. By recognizing patients with DIVA before the first insertion attempt and treating them from the outset with advanced vein visualization techniques, patients with DIVA could be subject to less frequent painful venipunctures, fewer delays in treatment, and a reduction in other DIVA-associated burdens.

Comparison of Clinical, Economic, and Humanistic Outcomes Between Blood Collection Approaches: A Systematic Literature Review.

BACKGROUND: A systematic literature review was performed to understand the prevalence, advantages, and disadvantages of blood collection using different approaches (direct venipuncture or vascular access devices), and interventions used to mitigate the disadvantages. METHODS: The review included a broad range of study designs and outcomes. Database searches (Embase, MEDLINE, Cochrane library, and Centre for Reviews and Dissemination) were conducted in March 2021 and supplemented by hand searching. RESULTS: One hundred forty-one publications were included. The data indicate that blood sampling from vascular access devices is common in emergency departments, trauma centers, and intensive care units. Studies showed that hemolysis and sample contamination place a considerable economic burden on hospitals. Significant cost savings could be made through enforcing strict aseptic technique, or using the initial specimen diversion technique. CONCLUSIONS: Hemolysis and sample contamination are far from inevitable in vascular access device-collected or venipuncture samples; both can be reduced through adherence to strict blood sampling protocols and utilization of the initial specimen diversion technique. Needle-free blood collection devices offer further hope for reducing hemolysis. No publication focused on the difficult venous access population; insertion success rates are likely to be lower (and the benefits of vascular access devices higher) in these patients.

Clinician satisfaction and preference for central venous catheter systems promoting patient safety, ease-of-use and reduced clinician error.

OBJECTIVES: Central venous catheters (CVC) are frequently utilized with limited data on user preferences. A simulation/survey-based study was conducted among anesthesia providers to evaluate attitudes toward general CVC system attributes, and satisfaction with elements of the most-commonly used and a novel CVC system. METHODS: Forty providers completed a simulation using both CVC systems and a 29-item questionnaire, including multiple-choice, free-text, ranking, and Likert-like questions. Ranking scores were reported using a scale of 0 (least important/satisfactory) to 100 (most important/satisfactory). Statistical significances were evaluated via Wilcoxon signed-rank sum test. RESULTS: Participants chose (mean±SD) patient safety (83.9 ± 25.3), ease-of-use (64.6 ± 26.1), and reduced risk for error (61.1 ± 26.7) as the most important attributes when considering a CVC system. Satisfaction levels were significantly higher for the novel system: overall (p < 0.001), its ease-of-use (p < 0.001), tray layout/design (p < 0.001), and safety (p = 0.012). Mean satisfaction scores were significantly higher for the novel system's potential to reduce 5 of 7 common issues, including clinician error (p < 0.001), and contamination/infection (p < 0.001). CONCLUSION: Anesthesia providers preferred CVC systems promoting patient safety, ease-of-use and reduce clinician error. Significantly higher (p < 0.05) satisfaction scores were awarded to a novel system featuring a sequentially organized tray, enhanced labeling, and a guidewire funnel.

Symptomatic Deep Vein Thrombosis Associated With Peripherally Inserted Central Catheters of Different Diameters: A Systematic Review and Meta-Analysis.

We assessed the relationship between peripherally inserted central catheter (PICC) diameters and symptomatic deep vein thrombosis (DVT) rates. We conducted a systematic search for articles published between 2010 and 2021 reporting DVT incidence by catheter diameter in patients who had a PICC, followed by meta-analyses for DVT risk in each diameter group. Pooled DVT rates were incorporated into an economic model. Of 1627 abstracts screened, 47 studies were included. The primary meta-analysis of 40 studies demonstrated the incidence of DVT was 0.89%, 3.26%, 5.46%, and 10.66% for 3, 4, 5, and 6 French (Fr) PICCs (P = .01 between 4 and 5 Fr). Rates of DVT were not significantly different between oncology and nononcology patients (P = .065 for 4 Fr and P = .99 for 5 Fr). The DVT rate was 5.08% for ICU patients and 4.58% for non-ICU patients (P = .65). The economic model demonstrated an annual, incremental cost savings of US$114 053 for every 5% absolute reduction in 6 Fr PICCs use. Using the smallest PICC that meets the patients' clinical needs may help to mitigate risks and confer savings.

Comparative Effectiveness, Efficiency, and ED Nurse Preference Between Two Methods of Visualization for Midline Catheter Insertion: A Pilot Study.

Introduction: Rapid and reliable peripheral IV access is essential for many patients admitted to the emergency department (ED) to ensure administration of life-saving medications, and successful intravenous cannulation can significantly affect patient care. Objective: The objective of this study was to assess the impact of a continuous needle tracking system on the accuracy, speed, and quality of ultrasound-guided peripheral venous catheter insertions. Methods: A convenient sample study based on the study setting using simulated tissue was conducted with 49 US-based ED nurses to compare the insertion of a midline catheter using traditional ultrasound guidance versus an advanced needle-tracking technology along with ultrasound guidance. The purpose of this evaluation was to assess the impact of continuous needle tracking system. Informed consent was obtained from all individual participants involved in this study. All participants were made aware that the results may be published. There was no IRB approval for this study. All sources were properly disclosed within the text. Results: The addition of the advanced needle-tracking technology significantly reduced total insertion attempts, insertion time, backwall penetrations, and redirects (probes to hit the target vein), while improving image clarity and confidence for participants. Conclusion: The innovative needle-tracking system evaluated in this pilot study has the potential to improve emergent difficult vascular access. EDs should assess the value of this technology to potentially improve the management of difficult intravenous access patients in their settings.

The Association Between Catheter Type and Dialysis Treatment: A Retrospective Data Analysis at Two U.S.-Based ICUs.

Dialysis catheter type may be associated with differences in continuous renal replacement therapy (CRRT) treatment in the critically ill, with potential implications for patient outcomes and healthcare costs. OBJECTIVES: To evaluate the association between the catheter type and multiple dialysis treatment outcomes among the critically ill. DESIGN: Retrospective, observational study. SETTING: Two U.S.-based ICUs. PARTICIPANTS: Critically ill patients receiving CRRT between April 1, 2018, and July 1, 2020. A total of 1,037 CRRT sessions were analyzed. MAIN OUTCOMES AND MEASURES: Circuit life, alarm interruption frequency (including a subset of vascular access [VA]-related alarms), termination type (elective vs nonelective), and blood flow rates. Pre- (n = 530) and post-catheter change (n = 507) periods were assessed, and the post-change period was further divided into intervals of pre-COVID (n = 167) and COVID contemporaneous (n = 340) to account for the pandemic's impact. RESULTS: Compared with pre-change sessions, post-change sessions had 31% longer circuit life (95% CI, 1.14-1.49; p < 0.001), 3% higher blood flow rate (1.01-1.05; p < 0.01), and lower proportion of nonelective terminations (adjusted odds ratio [OR], 0.42 [0.28-0.62]; p < 0.001). There were fewer interruptions for all alarms (adjusted count ratio, 0.95 [0.87-1.05]; p = 0.31) and VA-related alarms (0.80 [0.66-0.96]; p = 0.014). The sessions during COVID period were statistically similar to pre-COVID sessions for all outcomes except a lower proportion of nonelective terminations (adjusted OR, 0.39 [0.22-0.70]; p < 0.01). CONCLUSIONS: A change in catheter type was associated with longer CRRT sessions with fewer interruptions and unexpected terminations in a population of critical patients.

Prevalence, causes, impacts, and management of needle phobia: An international survey of a general adult population.

Needle phobia is an overlooked condition that affects virtually all medical procedures. Our study aimed to identify how commonly needle phobia is experienced, its underlying reasons, impacts, and potential mitigation strategies. A global survey was conducted in a general adult population using a questionnaire based on a targeted literature review that identified under-researched areas. The 21-item questionnaire was completed on a secure, web-based survey platform. Statistical analyses and models were utilized to identify relationships between participant characteristics and needle phobia. Of the 2,098 participants enrolled in the study, 63.2% (n = 1,325) reported experiencing needle phobia, and rated the intensity of their fear as 5.7 (±2.6) on average on a scale from 0 (no fear) to 10 (very strong/unreasonable fear or avoidance). According to the logistic regression model, other medical fears (odds coefficient = 2.14) and family history (1.67) were the most important factors associated with needle phobia. General anxiety (96.1%) and pain (95.5%) were the most common reasons for needle fear. Of the participants experiencing needle phobia, 52.2% stated avoiding blood draws, followed by 49.0% for blood donations, and 33.1% for vaccinations. While 24.3% of participants have seen a therapist, most have never sought help. The majority have shared their fear with nurses (61.1%) or physicians (44.4%); however, the provider helpfulness was rated as 4.9 (±3.1) on average on a scale from 0 (unhelpful) to 10 (extremely helpful). Utilizing non-invasive alternatives (94.1%) and smaller needles (91.1%) were most commonly identified as potential device-related solutions to alleviate fear; distractions (92.1%) and relaxation techniques (91.7%) were the top non-device-related approaches. Our findings highlight the prevalent nature of needle phobia and provide insights into its etiology and effects on patient care. Clinician responses were not perceived as helpful, emphasizing the need to address needle phobia, and improve patient experience.

Patient Experience With Vascular Access Management Informs Satisfaction With Overall Hospitalization Experience.

Peripheral intravenous catheter (PIVC) insertion is a common invasive procedure performed during hospitalization. The present study reports results from a survey of 544 patients who have had PIVC insertion during their hospital stay in Singapore and the Philippines during the period between November 2018 and February 2019. The survey assessed the importance of 5 domains of patient-centered care on patient satisfaction with their hospitalization experience, including pain management, infection prevention, health care provider competence with vascular access, physical comfort, and effectiveness of communication during vascular access management. Health care provider competence, infection prevention, and pain management ranked as the most important determinants of patient satisfaction. Patients were more likely to lose their trust in health care providers and express anxiety if they experienced multiple needle insertion attempts or PIVC-related complications, whereas patients who were satisfied with their PIVC insertion were more likely to express satisfaction with their overall hospital stay. Improving vascular access management with a focus on enhancing vascular access skills, infection prevention, and pain management may improve patient satisfaction.

Defining difficult intravenous access (DIVA): A systematic review.

BACKGROUND: The term "difficult intravenous access" (DIVA) is commonly used but not clearly defined. Repeated attempts at peripheral intravenous catheter (PIVC) insertion can be a traumatic experience for patients, leading to sub-optimal clinical and economic outcomes. We conducted a systematic literature review (SLR) to collate literature definitions of DIVA, with the aim of arriving at an evidence-driven definition. METHODS: The SLR was designed to identify clinical, cost, and quality of life publications in patients requiring the insertion of a PIVC in any setting, including studies on US-guidance and/or guidewire, and studies with no specific intervention. The search was restricted to English language studies published between 1st January 2010 and 30th July 2020, and the Ovid platform was used to search several electronic databases, in addition to hand searching of clinical trial registries. RESULTS: About 121 studies were included in the SLR, of which 64 reported on the objectives relevant to this manuscript. Prevalence estimates varied widely from 6% to 87.7% across 19 publications, reflecting differences in definitions used. Of 43 publications which provided a definition of DIVA, six key themes emerged. Of these, themes 1-3 (failed attempts at PIV access using traditional technique; based on physical examination findings for example no visible or palpable veins; and personal history of DIVA) were covered by all but one publication. Following a failed insertion attempt, the most common number of subsequent attempts was 3, and it was frequently reported that a more experienced clinician would attempt to gain access after multiple failed attempts. CONCLUSIONS: Considering the themes identified, an evidence-driven definition of DIVA is proposed: "when a clinician has two or more failed attempts at PIV access using traditional techniques, physical examination findings are suggestive of DIVA (e.g. no visible or palpable veins) or the patient has a stated or documented history of DIVA."

Neuraxial and peripheral misconnection events leading to wrong-route medication errors: a comprehensive literature review.

We conducted a search of the literature to identify case reports of neuraxial and peripheral nervous system misconnection events leading to wrong-route medication errors. This narrative review covers a 20-year period (1999-2019; English-language publications and abstracts) and included the published medical literature (PubMed and Embase) and public access documents. Seventy-two documents representing 133 case studies and 42 unique drugs were determined relevant. The most commonly reported event involved administering an epidural medication by an intravenous line (29.2% of events); a similar proportion of events (27.7%) involved administering an intravenous medication by an epidural line. Medication intended for intravenous administration, but delivered intrathecally, accounted for 25.4% of events. In the most serious cases, outcomes were directly related to the toxicity of the drug that was unintentionally administered. Patient deaths were reported due to the erroneous administration of chemotherapies (n=16), muscle relaxants (n=4), local anesthetics (n=4), opioids (n=1), and antifibrinolytics (n=1). Severe outcomes, including paraplegia, paraparesis, spinal cord injury, and seizures were reported with the following medications: vincristine, gadolinium, diatrizoate meglumine, doxorubicin, mercurochrome, paracetamol, and potassium chloride. These case reports confirm that misconnection events leading to wrong-route errors can occur and may cause serious injury. This comprehensive characterization of events was conducted to better inform clinicians and policymakers, and to describe an emergent strategy designed to mitigate patient risk.

A randomized, open, parallel group, multicenter trial to investigate analgesic efficacy and safety of a new transdermal fentanyl patch compared to standard opioid treatment in cancer pain.

A new 72-hour transdermal fentanyl matrix patch has been designed, which has a 35%-50% reduction of the absolute fentanyl content compared with other currently available transdermal fentanyl patches that are using the matrix technology. The new patch has previously been shown to be pharmacokinetically bioequivalent to the marketed fentanyl patch. To determine noninferiority in efficacy in cancer patients and to compare safety, a clinical trial comparing the new fentanyl patch with standard oral or transdermal opioid treatment was planned. The design was an open, parallel group, multicenter trial, in which 220 patients were randomized to receive either the fentanyl patch or standard opioid treatment for 30 days. The primary efficacy variable, pain intensity (PI) on a 0-10-point numerical rating scale, was recorded once daily. The primary endpoint was the relative area under the curve of PI expressed as a percentage of the maximum possible PI area under the curve. Any adverse events were recorded; four tolerability endpoints, constipation, nausea, daytime drowsiness, and sleeping disturbances, were assessed daily. Noninferiority was shown; the upper 95% confidence interval limits of the mean difference in relative PI area under the curve between the fentanyl patch and standard opioid treatment were less than 10% for both the intention-to-treat and per-protocol populations. Scores for the tolerability endpoints were similar in the treatment groups. The new fentanyl matrix patch with a lower drug load was found noninferior and as safe as established standard oral and transdermal opioid treatment.

Efficacy and safety of transdermal buprenorphine: a randomized, placebo-controlled trial in 289 patients with severe cancer pain.

Strong opioids are recommended for treating severe cancer pain in the advanced stages of the disease. Few data are available concerning the efficacy of buprenorphine in cancer pain. We compared transdermal buprenorphine 70 microg/h (BUP TDS) to placebo in an enriched design study. Opioid-tolerant patients with cancer pain requiring strong opioids in the dose range of 90-150 mg/d oral morphine equivalents entered a two-week run-in phase, during which they were converted to BUP TDS. Patients who could be stabilized on BUP TDS were randomized to BUP TDS or placebo patch for a two-week maintenance phase. Rescue medication (buprenorphine sublingual tablets 0.2mg) was allowed as required. Response was defined as a mean pain intensity of <5 (0-10 scale) and a mean daily buprenorphine sublingual tablet intake of < or =2 tablets during the maintenance phase. Of 289 patients who entered the run-in phase, 100 discontinued treatment due to lack of efficacy or adverse events; 189 patients continued treatment in the maintenance phase (94 BUP TDS, 95 placebo), of whom 31 discontinued treatment (7 BUP TDS, 24 placebo). A significant difference in the number of treatment responders was observed: 70 BUP TDS (74.5%, 65.7-83.3) vs. 47 placebo (50%, 39.9-60.1) (P=0.0003). This result was supported by a lower daily pain intensity, lower intake of buprenorphine sublingual tablets and fewer dropouts in the BUP TDS group. The incidence of adverse events was slightly higher for BUP TDS. In conclusion, BUP TDS 70 microg/h is an efficacious and safe treatment for patients with severe cancer pain.

Non-isotopic tyrosine kinetics using an alanyl-tyrosine dipeptide to assess graft function in liver transplant recipients - a pilot study.

BACKGROUND: Although accurate assessment of liver function in liver transplant recipients is of crucial importance for optimal timing of the procedure and for determining graft viability, none of the many available methods has proven reliable in the clinical routine. Thus, a novel non-isotopic assay of tyrosine kinetics using the tyrosine-containing dipeptide L-alanyl-L-tyrosine (Ala-Tyr) was tested for its clinical feasibility in patients undergoing orthotopic liver transplantation (OLT). METHODS: Plasma levels of tyrosine and clearance of tyrosine released after infusion of the dipetide Ala-Tyr were assessed before and one day after OLT in 10 liver transplant recipients with normal graft function, also in three organ donors and in three recipients showing poor graft function. Standard laboratory parameters (e.g. aminotransferases) and the plasma disappearance rate of indocyanine green were also measured. RESULTS: Following uneventful OLT, tyrosine plasma levels (before 127 +/- 15 micromol/vs. post-OLT 52 +/- 6 micromol/l, P < 0.05) and kinetics (tyrosine clearance: before 206 +/- 77 ml/min vs. post-OLT 371 +/- 109 ml/min, P < 0.05) were normalized. In cases of severe graft dysfunction, tyrosine kinetics (tyrosine clearance: 238 +/- 61 ml/min) resembled the situation in end-stage liver disease, whereas no such correlation was seen with conventional markers of liver function. Organ preservation had only a minor impact on tyrosine kinetics (n.s.). CONCLUSION: OLT rapidly normalizes both the plasma levels and the kinetics of tyrosine. Graft failure is associated with an immediate rise in plasma tyrosine levels and a delay in tyrosine elimination. Our results show that tyrosine clearance using the dipetide Ala-Tyr is a suitable non-isotopic, non-invasive indicator of graft viability in the early postoperative course following OLT.

Results from Austria's nationwide public access defibrillation (ANPAD) programme collected over 2 years.

AIM OF THE STUDY: To analyse 2 years of experience after introducing automated external defibrillators (AED) all over Austria. MATERIALS AND METHODS: This observational study evaluated the number of privately purchased devices and the rate of local bystander-triggered AED deployments from November 2002 to December 2004. As outcome measurements, the hospital discharge rate and neurological condition were recorded. Arrival times of the emergency medical service (EMS) on scene and the time intervals until shock decisions were made were calculated. Shock decisions were verified according to ECG downloads. Results were compared with historical data if applicable. RESULTS: During the study period, 1865 devices were installed. Seventy-three AED deployments were recorded. Eleven cases were excluded from the study because bystanders were part of the local EMS. Seventeen out of the remaining 62 (27%) compared to a historical 27 out of 623 (4.3%) individuals were discharged alive from hospital. Fourteen out of 26 (54%) patients who were found with a shockable rhythm survived to hospital discharge. Fifteen of our patients survived in good neurological condition (CPC I and II), two suffered from severe neurological deficit (CPC III and IV) and 45 people died. The median "call-to-AED advice interval" was 3.5 min (IQR 2-6 min; N=24). In two cases, the AED made inappropriate decisions because of artefacts. CONCLUSIONS: Compared to historical data, short 'intervals to shock' delivery and the frequent start of basic life support resulted in an increased hospital discharge rate in good neurological condition. Despite the relatively high number of installed devices, the number of patients reached remained small.

Prehospital analgesia with acupressure at the Baihui and Hegu points in patients with radial fractures: a prospective, randomized, double-blind trial.

BACKGROUND: Pain during transportation is a common phenomenon in emergency medicine. As acupressure has been deemed effective for pain management by the National Institutes of Health, we conducted a study to evaluate its effectiveness in prehospital patients with isolated distal radial fracture. METHODS: This was a prospective, randomized, double-blind study. Thirty-two patients were enrolled. Acupressure was performed either at "true" points or at "sham" points. Vital signs and pain and anxiety scores were recorded before and after the acupressure treatment. Normally distributed values were compared using the Student t test. RESULTS: Pretreatment scores for pain and anxiety were similar in the 2 groups (47.6 +/- 8.9 vs 51.2 +/- 8.7 visual analog scale [VAS] score for pain, 52.4 +/- 6.0 vs 47.5 +/- 9.3 VAS score for anxiety). At the hospital, patients in the true-points group had significantly lower pain (36.6 +/- 11.0 vs 56.0 +/- 13.3 VAS score, P < .001) and anxiety scores (34.9 +/- 22.2 vs 53.4 +/- 19.7 VAS score, P = .022). CONCLUSION: Acupressure in the prehospital setting effectively reduces pain and anxiety in patients with distal radial trauma.

The influence of stellate ganglion transcutaneous electrical nerve stimulation on signal quality of pulse oximetry in prehospital trauma care.

BACKGROUND: Accurate monitoring of the peripheral arterial oxygen saturation has become an important tool in the prehospital emergency medicine. This monitoring requires an adequate plethysmographic pulsation. Signal quality is diminished by cold ambient temperature due to vasoconstriction. Blockade of the stellate ganglion can improve peripheral vascular perfusion and can be achieved by direct injection or transcutaneous electrical nerve stimulation (TENS) stimulation. We evaluated whether TENS on the stellate ganglion would reduce vasoconstriction and thereby improve signal detection quality of peripheral pulse oximetry. METHODS: In our study, 53 patients with minor trauma who required transport to the hospital were enrolled. We recorded vital signs, including core and skin temperature before and after transport to the hospital. Pulse oximetry sensors were attached to the patient's second finger on both hands. TENS of the stellate ganglion was started on one side after the beginning of the transport. Pulse oximeter alerts, due to poor signal detection, were recorded for each side separately. RESULTS: On the hand treated with TENS we detected a significant reduction of alerts compared to the other side (mean alerts TENS 3.1 [1-15] versus control side 8.8 [1-28] P < 0.05). The duration of dropouts was shorter as well (mean duration TENS 77 [16-239] s versus control side 333 [78-1002] s). CONCLUSION: The data indicate that blockade of the stellate ganglion with TENS improves signal quality of pulse oximeters in the prehospital setting.

Which of the abbreviated burn severity index variables are having impact on the hospital length of stay?

Quality control is an important tool ensuring continuous medical efficacy. Outcome scores, however, are unfavorable from a statistical point of view, are not meaningful for less severely injured patients, and may put the treating physicians under pressure to limit therapeutic efforts. In this study the variables of the abbreviated burn severity index (ABSI), primarily an outcome score, were used to predict length of hospital stay (HLS), a continuous quantitative variable reflecting treatment costs and incidence of complications even in less severely injured patients. For 365 patients a multiple linear regression analysis was used to evaluate the influence of the ABSI variables on HLS. Among survivors, age and total body surface area burned (TBSA) contributed significantly to HLS, whereas for nonsurvivors only TBSA significantly influenced HLS. Neither gender nor presence of full-thickness burn or inhalation injury showed a significant influence on HLS. The impact of age and TBSA on HLS might be used as a benchmarking system to evaluate quality of care. However, although HLS is probably widely dependent on regional health care systems, TBSA and age proved to be the only variables of the ABSI to correlate with HLS.

Automated external defibrillators do not recommend false positive shocks under the influence of electromagnetic fields present at public locations.

Electromagnetic fields (EMF) reduce the signal quality of electrocardiograms and may lead to the misinterpretation by automated external defibrillators (AED). We designed this investigation as a prospective study, with a randomized sequence of AED applications on healthy volunteers. We chose busy public places where public access defibrillation was possible as test locations. Strong EMF were sought and found at train stations next to accelerating and decelerating trains. The primary outcome variable was the absolute number of shocks advised in the presence of sinus rhythm by five commonly used AED in Austria. For data analysis, the statistician was blinded in regard to the AED models tested. Data analysis was based on a per protocol evaluation. Of 390 tests run, 0 cases of false positive results occurred (95% CI: 0-0.77). AED can be regarded as safe, even with the interference of EMF present at train stations.