Reporting standard for describing first responder systems, smartphone alerting systems, and AED networks.

Standardized reporting of data is crucial for out-of-hospital cardiac arrest (OHCA) research. While the implementation of first responder systems dispatching volunteers to OHCA is encouraged, there is currently no uniform reporting standard for describing these systems. A steering committee established a literature search to identify experts in smartphone alerting systems. These international experts were invited to a conference held in Hinterzarten, Germany, with 40 researchers from 13 countries in attendance. Prior to the conference, participants submitted proposals for parameters to be included in the reporting standard. The conference comprised five workshops covering different aspects of smartphone alerting systems. Proposed parameters were discussed, clarified, and consensus was achieved using the Nominal Group Technique. Participants voted in a modified Delphi approach on including each category as a core or supplementary element in the reporting standard. Results were presented, and a writing group developed definitions for all categories and items, which were sent to participants for revision and final voting using LimeSurvey web-based software. The resulting reporting standard consists of 68 core items and 21 supplementary items grouped into five topics (first responder system, first responder network, technology/algorithm/strategies, reporting data, and automated external defibrillators (AED)). This proposed reporting standard generated by an expert opinion group fills the gap in describing first responder systems. Its adoption in future research will facilitate comparison of systems and research outcomes, enhancing the transfer of scientific findings to clinical practice.

Behavioural digital biomarkers enable real-time monitoring of patient-reported outcomes: a substudy of the multicenter, prospective observational SafeHeart study.

INTRODUCTION: Patient-reported outcome measures (PROMs) serve multiple purposes, including shared decision-making and patient communication, treatment monitoring and health-technology assessment. Patient monitoring using PROMs is constrained by recall and non-response bias, respondent burden and missing data. We evaluated the potential of behavioural digital biomarkers obtained from a wearable accelerometer to achieve personalised predictions of PROMs. METHODS: Data from the multicenter, prospective SafeHeart study conducted at Amsterdam University Medical Center in the Netherlands and Copenhagen University Hospital, Rigshospitalet in Copenhagen, Denmark, was used. The study enrolled patients with an implantable cardioverter defibrillator (ICD) between May 2021 and September 2022 who then wore wearable devices with raw acceleration output to capture digital biomarkers reflecting physical behaviour. To collect PROMs, patients received the KCCQ and EQ5D-5 L questionnaire at two instances; baseline and after 6 months. Multivariable Tobit regression models were used to explore associations between digital biomarkers and PROMs, specifically whether digital biomarkers could enable PROM prediction. RESULTS: The study population consisted of 303 patients (mean age 62.9 ± 10.9 years, 81.2% male). Digital biomarkers showed significant correlations to patient-reported physical and social limitations, severity and frequency of symptoms and quality of life. Prospective validation of the Tobit models indicated moderate correlations between the observed and predicted scores for KCCQ (concordance correlation coefficient (CCC) = 0.49, mean difference: 1.07 points) and EQ5D-5 L (CCC = 0.38, mean difference 0.02 points). CONCLUSION: Wearable digital biomarkers correlate with PROMs, and may be leveraged for real-time prediction. These findings hold promise for monitoring of PROMs through wearable accelerometers.

Termination of resuscitation in out-of-hospital cardiac arrest in women and men: An ESCAPE-NET project.

AIM: Women have less favorable resuscitation characteristics than men. We investigated whether the Advanced Life Support Termination of Resuscitation rule (ALS-TOR) performs equally in women and men. Additionally, we studied whether adding or removing criteria from the ALS-TOR improved classification into survivors and non-survivors. METHODS: We analyzed 6,931 female and 14,548 male out-of-hospital cardiac arrest (OHCA) patients from Dutch and Swedish registries, and validated in 10,772 female and 21,808 male Danish OHCA patients. Performance measures were calculated for ALS-TOR in relation to 30-day survival. Recursive partitioning analysis was performed with the ALS-TOR criteria, as well as age, comorbidities, and additional resuscitation characteristics (e.g. initial rhythm, OHCA location). Finally, we explored if we could reduce the number of ALS-TOR criteria without loss of prognostic value. RESULTS: The ALS-TOR had a specificity and positive predictive value (PPV) of ≥99% in both women and men (e.g. PPV 99.9 in men). Classification by recursive partitioning analysis showed a high sensitivity but a PPV below 99%, thereby exceeding the acceptable miss rate of 1%. A combination of no return of spontaneous circulation (ROSC) before transport to the hospital and unwitnessed OHCA resulted in nearly equal specificity and PPV, higher sensitivity, and a lower transport rate to the hospital than the ALS-TOR. CONCLUSION: For both women and men, the ALS-TOR has high specificity and low miss rate for predicting 30-day OHCA survival. We could not improve the classification with additional characteristics. Employing a simplified version may decrease the number of futile transports to the hospital.

[Application of lateral upper arm free flap in the repair of postoperative defects of oral cancer].

Objective: To explore the clinical application and efficacy of lateral upper arm free flap (LUAFF) for one-stage repairing of soft tissue defect after oral cancer surgery. Methods: This article was a retrospective analysis of clinical data of 46 patients receiving treatment of one-stage repairing of soft tissue defect with LUAFF after oral cancer surgery in Hunan Cancer Hospital, from June 2019 to June 2021. Among these cases, 40 were males, and 6 were females. The patients' ages were from 23 to 64 years old. The clinical data of patients were reviewed and outcomes were evaluated. SPSS 23.0 software was used for statistical analysis. Results: In the LUAFF of 46 patients, flap area ranged from 5.0 cm×3.5 cm to 15.0 cm×7.0 cm; the mean pedicle length was 8.15±1.42 cm; the mean artery diameter was 1.20±0.41 mm (range, 1.5 to 2.5 mm); the mean diameter of the largest veins was 2.15±0.52 mm; and the median number of perforators was 2.6 (range, 1 to 4). All donor sites were closed primarily. Two cases had arterial anastomosis thrombosis, but their flaps were successfully saved with urgent re-anastomosis of the vessels. The overall flap survival rate was 93.5%(43/46), with flap necroses after operation in three cases. No patient received tracheotomy. The average hospital stay time of patients after operation was 9.4 days. The follow-up time was 6-24 months, elbow and wrist movements on the operative side were normal, and the upper limb muscle strength was not affected. Conclusions: LUAFF is a suitable choice for the repairs of small-moderate tissue defects in oral cancer surgery, with consistent perforators in the flap, simple harvest method, concealed donor-site scar, and high survival rate.

[Oxidative stress in psychosis: a new target for intervention?] / Oxidatieve stress bij psychotische stoornissen: een nieuw target voor interventie?

BACKGROUND: Oxidative stress is a state of imbalance between reactive oxidants and anti-oxidants. Oxidative stress and a disrupted redox regulation in the brain might contribute to the pathophysiology of psychotic disorders and could serve as interesting new targets for clinical intervention. Advanced glycation end products (AGEs) in the skin can be measured non-invasively and indicate cumulative oxidative stress. AIM: To investigate cross-sectional and longitudinal differences in AGE-levels in patients with recent onset psychosis (patients) and healthy controls (controls). To investigate association of AGE-levels and brain volume in psychosis. METHOD: An autofluorescence measurement of AGEs in the skin was performed in patients and controls. AGEs were compared in patients and controls. Furthermore, the association between AGEs and volumes of the amygdala, hippocampus and total cortical gray matter was investigated in patients. RESULTS: AGEs in the skin were elevated by 15% (or 0.66 standard deviations) in patients (n = 86) compared to controls (n = 135) (p < 0.001). An indication of a higher AGE-accumulation rate (p = 0.07) was found in patients (n = 66) compared to controls (n = 160). We found a negative association between AGEs in the skin and hippocampus volume (standardized beta= 0.27; p = 0.03) in patients (n = 46). CONCLUSION: Findings of a high level of AGEs in the skin indicate excessive oxidative stress in patients with recent onset psychosis.

Rationale and design of the PHOspholamban RElated CArdiomyopathy intervention STudy (i-PHORECAST).

BACKGROUND: The p.Arg14del (c.40_42delAGA) phospholamban (PLN) pathogenic variant is a founder mutation that causes dilated cardiomyopathy (DCM) and arrhythmogenic cardiomyopathy (ACM). Carriers are at increased risk of malignant ventricular arrhythmias and heart failure, which has been ascribed to cardiac fibrosis. Importantly, cardiac fibrosis appears to be an early feature of the disease, occurring in many presymptomatic carriers before the onset of overt disease. As with most monogenic cardiomyopathies, no evidence-based treatment is available for presymptomatic carriers. AIMS: The PHOspholamban RElated CArdiomyopathy intervention STudy (iPHORECAST) is designed to demonstrate that pre-emptive treatment of presymptomatic PLN p.Arg14del carriers using eplerenone, a mineralocorticoid receptor antagonist with established antifibrotic effects, can reduce disease progression and postpone the onset of overt disease. METHODS: iPHORECAST has a multicentre, prospective, randomised, open-label, blinded endpoint (PROBE) design. Presymptomatic PLN p.Arg14del carriers are randomised to receive either 50 mg eplerenone once daily or no treatment. The primary endpoint of the study is a multiparametric assessment of disease progression including cardiac magnetic resonance parameters (left and right ventricular volumes, systolic function and fibrosis), electrocardiographic parameters (QRS voltage, ventricular ectopy), signs and/or symptoms related to DCM and ACM, and cardiovascular death. The follow-up duration is set at 3 years. BASELINE RESULTS: A total of 84 presymptomatic PLN p.Arg14del carriers (n = 42 per group) were included. By design, at baseline, all participants were in New York Heart Association (NHYA) class I and had a left ventricular ejection fraction > 45% and < 2500 ventricular premature contractions during 24-hour Holter monitoring. There were no statistically significant differences between the two groups in any of the baseline characteristics. The study is currently well underway, with the last participants expected to finish in 2021. CONCLUSION: iPHORECAST is a multicentre, prospective randomised controlled trial designed to address whether pre-emptive treatment of PLN p.Arg14del carriers with eplerenone can prevent or delay the onset of cardiomyopathy. iPHORECAST has been registered in the clinicaltrials.gov-register (number: NCT01857856).

[Classification and reconstruction of complex defects after lateral facial tumor surgery].

Objective: To explore the classification and reconstruction strategy of defects in lateral face region after operation of malignant tumors. Methods: Eighteen cases with the reconstruction of complicated defects after resection of tumors in the region of lateral face from January 2015 to January 2018 in Hunan Cancer Hospital were retrospectively reviewed. There were 14 males and 4 females, aged from 32 to 68 years. According to the presence or absence of bony scaffold, complicated defects were divided into two main categories: soft tissue perforating defects and soft tissue defects combined with bony scaffold defects. All soft tissue perforating defects in 5 cases were repaired with free anterolateral femoral flaps. Among 13 cases with soft tissue plus bony scaffold defects, 3 were repaired with free fibular flaps, 6 with free fibular flaps combined with free anterolateral femoral flaps, and 4 with chimeric deep circumflex iliac artery perforator flaps combined with anterolateral femoral flaps. Results: All flaps survived well. Two patients complicated with fistula in floor of mouth, but the wound healed after dressing change. Transoral feeding was resumed within 2 weeks after surgery in all patients. One year follow-up evaluation showed that 14 cases had symmetrical face and 10 cases had mouth opening more than 3 transverse fingers. After 36-50 months of follow-up, 6 patients died, with an overall 3-year survival rate of 66.7%. Conclusion: The classification of defects with or without bony stent loss is conducive to the overall repair design, the recovery of facial contour stent, the effective fill of dead space and the maintain of residual occlusal relationship. Good reconstruction results require a multi flap combination of osteocutaneous and soft tissue flaps.

Temporal variation in out-of-hospital cardiac arrest occurrence in individuals with or without diabetes.

OBJECTIVE: Out-of-hospital cardiac arrest (OHCA) occurrence has been shown to exhibit a circadian rhythm, following the circadian rhythm of acute myocardial infarction (AMI) occurrence. Diabetes mellitus (DM) is associated with changes in circadian rhythm. We aimed to compare the temporal variation of OHCA occurrence over the day and week between OHCA patients with DM and those without. METHODS: In two population-based OHCA registries (Amsterdam Resuscitation Studies [ARREST] 2010-2016, n = 4163, and Danish Cardiac Arrest Registry [DANCAR], 2010-2014, n = 12,734), adults (≥18y) with presumed cardiac cause of OHCA and available medical history were included. Single and double cosinor analysis was performed to model circadian variation of OHCA occurrence. Stratified analysis of circadian variation was performed in patients with AMI as immediate cause of OHCA. RESULTS: DM patients (22.8% in ARREST, 24.2% in DANCAR) were older and more frequently had cardiovascular risk factors or previous cardiovascular disease. Both cohorts showed 24 h-rhythmicity, with significant amplitudes in single and double cosinor functions (P-range < 0.001). In both registries, a morning peak (10:00-11:00) and an evening peak (20:00-21:00) was observed in both DM and non-DM patients. No septadian variation was observed in either DM or non-DM patients (P-range 0.13-84). CONCLUSIONS: In these two population-based OHCA registries, we observed a similar circadian rhythm of OHCA occurrence in DM and non-DM patients.

The effect of the localisation of an underlying ST-elevation myocardial infarction on the VF-waveform: A multi-centre cardiac arrest study.

INTRODUCTION: In cardiac arrest, ventricular fibrillation (VF) waveform characteristics such as amplitude spectrum area (AMSA) are studied to identify an underlying myocardial infarction (MI). Observational studies report lower AMSA-values in patients with than without underlying MI. Moreover, experimental studies with 12-lead ECG-recordings show lowest VF-characteristics when the MI-localisation matches the ECG-recording direction. However, out-of-hospital cardiac arrest (OHCA)-studies with defibrillator-derived VF-recordings are lacking. METHODS: Multi-centre (Amsterdam/Nijmegen, the Netherlands) cohort-study on the association between AMSA, ST-elevation MI (STEMI) and its localisation. AMSA was calculated from defibrillator pad-ECG recordings (proxy for lead II, inferior vantage point); STEMI-localisation was determined using ECG/angiography/autopsy findings. RESULTS: We studied AMSA-values in 754 OHCA-patients. There were statistically significant differences between no STEMI, anterior STEMI and inferior STEMI (Nijmegen: no STEMI 13.0mVHz [7.9-18.6], anterior STEMI 7.5mVHz [5.6-13.8], inferior STEMI 7.5mVHz [5.4-11.8], p = 0.006. Amsterdam: 11.7mVHz [5.0-21.9], 9.6mVHz [4.6-17.2], and 6.9mVHz [3.2-16.0], respectively, p = 0.001). Univariate analyses showed significantly lower AMSA-values in inferior STEMI vs. no STEMI; there was no significant difference between anterior and no STEMI. After correction for confounders, adjusted absolute AMSA-values were numerically lowest for inferior STEMI in both cohorts, and the relative differences in AMSA between inferior and no STEMI was 1.4-1.7 times larger than between anterior and no STEMI. CONCLUSION: This multi-centre VF-waveform OHCA-study showed significantly lower AMSA in case of underlying STEMI, with a more pronounced difference for inferior than for anterior STEMI. Confirmative studies on the impact of STEMI-localisation on the VF-waveform are warranted, and might contribute to earlier diagnosis of STEMI during VF.

Severe central airway stenosis and tracheomalacia in hunter syndrome.

Hunter Syndrome is a genetic disease characterized by deficiency of Iduronate-2-Sulfatase enzyme activity, resulting in accumulation of glycoaminoglycans in various organs including the central airways. We report a case of severe tracheomalacia and airway stenosis at Hospital Sultanah Aminah, Johor Bahru, Malaysia requiring mechanical ventilation in a middle aged gentleman who was previously undiagnosed of mucopolysaccharidosis. The patient underwent emergency tracheostomy for failed intubation, when he presented with shortness of breath and acute respiratory failure. A contrast-enhanced computed tomography of the neck and thorax revealed that the trachea distal to the tracheostomy tube had collapsed with narrowed right and left main bronchus. These findings were confirmed via direct visualization of the airway through a flexible bronchoscopy. Eventually, a tracheal stenting were performed to maintain the airway patency and assist in weaning off from mechanical ventilation. Further investigations to identify the aetiology of the central airway stenosis revealed elevated urinary glycoaminoglycans and the absence of iduronate-2-Sulfatase activity tested on dried blood spots, thus confirming the diagnosis of Hunter Syndrome. Managing mucopolysacharidosis with central airway obstruction requires multidisciplinary team effort in handling the difficult airway, anaesthesiology risk, potential comorbidities and providing genetic counselling.

Patient perspectives on priorities for research on conventional and sex- and gender-related cardiovascular risk factors.

BACKGROUND: Recently, cardiovascular disease (CVD) research has focused on sex- and gender-related cardiovascular risk factors, in addition to conventional risk factors. This raises the question which factors are perceived by the target group (patients with CVD) as priorities for further research. METHODS: We carried out a survey to study priority setting for more research into conventional and sex- and gender-related risk factors according to 980 men and women with CVD or those at increased risk of CVD in the Netherlands. Data on conventional and sex- and gender-related risk factors were descriptively analysed, stratified by gender group. RESULTS: The most frequently prioritised conventional factors according to men were heritability, overweight and unhealthy diet, while women most frequently listed stress, heritability and hypertension. The most frequently prioritised sex- and gender-related risk factors were depression or depressive feelings, migraine and having many caretaking responsibilities (men), and pregnancy complications, contraceptive pill use and early age at menopause (women). New research on sex- and gender-related risk factors was perceived roughly as relevant as that on conventional factors by men (mean 7.4 and 8.3 on a 1-10 scale, respectively) and women (8.2 and 8.6, respectively). Ethnic and gender minority groups placed more emphasis on risk factors related to sociocultural aspects (gender) than the majority group. CONCLUSION: Men and women with CVD or those at increased risk of CVD perceived new research on conventional and sex- and gender-related risk factors as a priority. These findings may guide researchers and funders in further prioritising new CVD research.

The application of dexmedetomidine combined with dezocine in thoracoscopic radical resection of lung cancer and its effect on awakening quality of patients.

OBJECTIVE: The paper aims to explore the application of dexmedetomidine combined with dezocine in thoracoscopic radical resection of lung cancer and its effect on the awakening quality. PATIENTS AND METHODS: 122 patients undergoing thoracoscopic radical resection of lung cancer in The Affiliated Hospital of Qingdao University from April 2009 to January 2012 were selected as the subjects of the study. Among them, 68 patients were anesthetized with dexmedetomidine combined with dezocine as a study group, 54 patients with midazolam combined with fentanyl as a control group. The onset of anesthetic, operation time, awakening time, extubation time, and recovery time was compared. The mean arterial pressure (MAP), central venous pressure (CVP), and heart rate (HR) were compared before anesthesia (t0), at extubation (t1), 10 min after extubation (t2), and when patients left anesthesia recovery room (t3). The postoperative sedation score (Ramsay), modified the objective pain score (MOPS), and the pediatric anesthesia emergence delirium (PAED) score were compared at the time of the postoperative awakening (b1), 30 min after awakening (b2), 1 hour after awakening (b3), and 3 hours after awakening (b4). RESULTS: There was no significant difference in MAP, CVP, and HR between the study group and the control group at t0 (p > 0.05). The scores of PAED at b3 and b4 in the study group were lower than those in the control group (p < 0.05). CONCLUSIONS: The anesthesia effect of dexmedetomidine combined with dezocine in thoracoscopic radical resection of lung cancer is better and safer than other drugs, and it can produce good sedation and analgesic effect.

Respiratory complications of metabolic disease in the paediatric population: A review of presentation, diagnosis and therapeutic options.

Inborn errors of metabolism (IEMs) whilst individually rare, as a group constitute a field which is increasingly demands on pulmonologists. With the advent of new therapies such as enzyme replacement and gene therapy, early diagnosis and treatment of these conditions can impact on long term outcome, making their timely recognition and appropriate investigation increasingly important. Conversely, with improved treatment, survival of these patients is increasing, with the emergence of previously unknown respiratory phenotypes. It is thus important that pulmonologists are aware of and appropriately monitor and manage these complications. This review aims to highlight the respiratory manifestations which can occur. It isdivided into conditions resulting primarily in obstructive airway and lung disease, restrictive lung disease such as interstitial lung disease or pulmonary alveolar proteinosis and pulmonary hypertension, whilst acknowledging that some diseases have the potential to cause all three. The review focuses on general phenotypes of IEMs, their known respiratory complications and the basic metabolic investigations which should be performed where an IEM is suspected.

[Extirpation of primary malignancies in the pterygopalatine and infratemporal fossa via modified maxillary swing approach].

Five patients with primary malignancies in the pterygopalatine fossa (PPF) and infra temporal fossa (ITF) were enrolled in this retrospective study between January 2012 and January 2018. After malignancies proven by biopsy and evaluation with CT and MRI scan, all patients received modified maxillary swing (MMS) approach for extirpation of malignant tumors in the PPF and ITF under general anesthesia. En bloc resection with wide surgical margins was successfully performed in all cases. Negative margins were observed in 4 cases and positive margins were found in one patient with adenoid cystic carcinoma who received postoperative radiotherapy. The most common complication was facial numbness. During the follow-up period (range 12 to 57 months), one patient suffered from recurrence while others did not. The advantages of MMS include wide surgical field, full exposure and easy manipulation. The MMS approach is expected to become an standard method for monobloc resection of malignancies in the PPF and ITF.

Association of solute carrier family 2, member 9 (SLC2A9) genetic variant rs3733591 with gout in a Malay sample set.

INTRODUCTION: Gout is one of the most common inflammatory arthritis in Malaysia. It is due to persistent hyperuricemia that leads to the formation and deposition of intra- and periarticular monosodium urate crystals either due to excessive production or insufficient excretion of uric acid. Incidence and prevalence of gout is increasing worldwide, with a higher rate among men compared to women. Malay is the largest ethnic group in Malaysia, followed by Chinese and Indian. SLC2A9 is a renal urate transporter that controls renal uric acid excretion and genetic variants in SLC2A9 are associated with the risk of gout in several populations. This study aimed to test if the SLC2A9 variant (R265H, rs3733591) is also associated with gout among Malays in Malaysia. METHODOLOGY: A total of 89 patients with gouty arthritis and 100 normal subjects who consented and were recruited in this study. The serum urate and creatinine were measured. The SNP genotyping was performed using PCR-RFLP method for rs3733591 and BST 1236 was used as a restriction enzyme to cut the targeted amplicons. RESULT: SLC2A9 variant was associated with gout, p-value of 0.007, OR=4.713 [95%CI 1.530-14.513], however this association was not significant after adjustment for age and gender with p=0.465 (OR=1.950; 95%CI[0.325-11.718]). CONCLUSION: Our data suggest that the genetic variant of SLC2A9 may contribute to the susceptibility of gout among Malays in Malaysia.

[Source tracing of the Yersinia pestis strains isolated from Heqing county, Yunnan province in 2017].

Objective: To understand the genotype of the Yersinia (Y.) pestis strains isolated from Heqing county, Yunnan province in 2017 and provide evidence for the prevention and control of plague in this area. Methods: Ten Y. pestis strains isolated from Heqing were typed by the detections of different region (DFR) and clustered regularly interspaced short palindromic repeats (CRISPRs) as well as multiple-locus variable-number tandem repeat analysis (MLVA). And the results were compared with those of the 93 Y. pestis strains from the adjacent plague foci of Heqing obtained from the established database for clustering analysis. Results: The results showed that Heqing strains had the same type of DFR (Genomovar 05) and CRISPRs (Cluster Ca7, Type 22) with isolates from the plague focus in Lijiang. Heqing strains and Lijiang strains were in the same cluster in MST and only VNTR loci N2117 and M23 of Heqing strains were different from that of Lijiang strains. Conclusion: The Y. pestis strains isolated from Heqing in 2017 were highly homogenous with the strains isolated from wild rodents in plague focus in Lijiang, and Heqing plague might be the result of further southward spread of Lijiang plague.

The challenges and possibilities of public access defibrillation.

Out-of-hospital cardiac arrest (OHCA) is a major health problem that affects approximately four hundred and thousand patients annually in the United States alone. It is a major challenge for the emergency medical system as decreased survival rates are directly proportional to the time delay from collapse to defibrillation. Historically, defibrillation has only been performed by physicians and in-hospital. With the development of automated external defibrillators (AEDs), rapid defibrillation by nonmedical professionals and subsequently by trained or untrained lay bystanders has become possible. Much hope has been put to the concept of Public Access Defibrillation with a massive dissemination of public available AEDs throughout most Western countries. Accordingly, current guidelines recommend that AEDs should be deployed in places with a high likelihood of OHCA. Despite these efforts, AED use is in most settings anecdotal with little effect on overall OHCA survival. The major reasons for low use of public AEDs are that most OHCAs take place outside high incidence sites of cardiac arrest and that most OHCAs take place in residential settings, currently defined as not suitable for Public Access Defibrillation. However, the use of new technology for identification and recruitment of lay bystanders and nearby AEDs to the scene of the cardiac arrest as well as new methods for strategic AED placement redefines and challenges the current concept and definitions of Public Access Defibrillation. Existing evidence of Public Access Defibrillation and knowledge gaps and future directions to improve outcomes for OHCA are discussed. In addition, a new definition of the different levels of Public Access Defibrillation is offered as well as new strategies for increasing AED use in the society.