Targeted prophylactic anticoagulation based on the TRiP(cast) score in patients with lower limb immobilisation: a multicentre, stepped wedge, randomised implementation trial.

BACKGROUND: Prophylactic anticoagulation in emergency department patients with lower limb trauma requiring immobilisation is controversial. The Thrombosis Risk Prediction for Patients with Cast Immobilisation-TRiP(cast)-score could identify a large subgroup of patients at low risk of venous thromboembolism for whom prophylactic anticoagulation can be safely withheld. We aimed to prospectively assess the safety of withholding anticoagulation for patients with lower limb trauma at low risk of venous thromboembolism, defined by a TRiP(cast) score of less than 7. METHODS: CASTING was a stepped-wedge, multicentre, cluster-randomised trial with blinded outcome assessment. 15 emergency departments in France and Belgium were selected and randomly assigned staggered start dates for switching from the control phase (ie, anticoagulation prescription according to the physician's usual practice) to the intervention phase (ie, targeted anticoagulation according to TRiP(cast) score: no prescription if score <7 and anticoagulation if score was ≥7). Patients were included if they presented to a participating emergency department with lower limb trauma requiring immobilisation for at least 7 days and were aged 18 years or older. The primary outcome was the 3-month cumulative rate of symptomatic venous thromboembolism during the intervention phase in patients with a TRiP(cast) score of less than 7. The targeted strategy was considered safe if this rate was less than 1% with an upper 95% CI of less than 2%. The primary analysis was performed in the intention-to-treat population. This study is registered at ClinicalTrials.gov (NCT04064489). FINDINGS: Between June 16, 2020, and Sept 15, 2021, 15 clusters and 2120 patients were included. Of the 1505 patients analysed in the intervention phase, 1159 (77·0%) had a TRiP(cast) score of less than 7 and did not receive anticoagulant treatment. The symptomatic venous thromboembolism rate was 0·7% (95% CI 0·3-1·4, n=8/1159). There was no difference between the control and the intervention phases in the cumulative rate of symptomatic venous thromboembolism or in bleeding rates. INTERPRETATION: Patients with a TRiP(cast) score of less than 7 who are not receiving anticoagulation have a very low risk of venous thromboembolism. A large proportion of patients with lower limb trauma and immobilisation could safely avoid thromboprophylaxis. FUNDING: French Ministry of Health.

Derivation and validation of a risk-stratification model for patients with probable or proven COVID-19 in EDs: the revised HOME-CoV score.

BACKGROUND: The HOME-CoV (Hospitalisation or Outpatient ManagEment of patients with SARS-CoV-2 infection) score is a validated list of uniquely clinical criteria indicating which patients with probable or proven COVID-19 can be treated at home. The aim of this study was to optimise the score to improve its ability to discriminate between patients who do and do not need admission. METHODS: A revised HOME-CoV score was derived using data from a previous prospective multicentre study which evaluated the original Home-CoV score. Patients with proven or probable COVID-19 attending 34 EDs in France, Monaco and Belgium between April and May 2020 were included. The population was split into a derivation and validation sample corresponding to the observational and interventional phases of the original study. The main outcome was non-invasive or invasive ventilation or all-cause death within 7 days following inclusion. Two threshold values were defined using a sensitivity of >0.9 and a specificity of >0.9 to identify low-risk and high-risk patients, respectively. The revised HOME-CoV score was then validated by retrospectively applying it to patients in the same EDs with proven or probable COVID-19 during the interventional phase. The revised HOME-CoV score was also tested against original HOME-CoV, qCSI, qSOFA, CRB65 and SMART-COP in this validation cohort. RESULTS: There were 1696 patients in the derivation cohort, of whom 65 (3.8%) required non-invasive ventilation or mechanical ventilation or died within 7 days and 1304 patients in the validation cohort, of whom 22 (1.7%) had a progression of illness. The revised score included seven clinical criteria. The area under the curve (AUC) was 87.6 (95% CI 84.7 to 90.6). The cut-offs to define low-risk and high-risk patients were <2 and >3, respectively. In the validation cohort, the AUC was 85.8 (95% CI 80.6 to 91.0). A score of <2 qualified 73% of patients as low risk with a sensitivity of 0.77 (0.55-0.92) and a negative predictive value of 0.99 (0.99-1.00). CONCLUSION: The revised HOME-CoV score, which does not require laboratory testing, may allow accurate risk stratification and safely qualify a significant proportion of patients with probable or proven COVID-19 for home treatment.

A new reservoir-based CPAP with low oxygen consumption: the Bag-CPAP.

BACKGROUND: Several noninvasive ventilatory supports rely in their design on high oxygen consumption which may precipitate oxygen shortage, as experienced during the COVID-19 pandemic. In this bench-to-bedside study, we assessed the performance of a new continuous positive airway pressure (CPAP) device integrating a large reservoir ("Bag-CPAP") designed to minimize oxygen consumption, and compared it with other CPAP devices. METHODS: First, a bench study compared the performances of Bag-CPAP and four CPAP devices with an intensive care unit ventilator. Two FiO2 targets (40-60% and 80-100%) at a predefined positive end expiratory pressure (PEEP) level between 5 and 10 cm H2O were tested and fraction of inspired oxygen (FiO2) and oxygen consumption were measured. Device-imposed work of breathing (WOB) was also evaluated. Second, an observational clinical study evaluated the new CPAP in 20 adult patients with acute respiratory failure in two hospitals in France. Actual FiO2, PEEP, peripheral oxygen saturation, respiratory rate, and dyspnea score were assessed. RESULTS: All six systems tested in the bench study reached the minimal FiO2 target of 40% and four reached at least 80% FiO2 while maintaining PEEP in the predefined range. Device-delivered FiO2/consumed oxygen ratio was the highest with the new reservoir-based CPAP irrespective of FiO2 target. WOB induced by the device was higher with Bag-CPAP. In the clinical study, Bag-CPAP was well tolerated and could reach high (> 90%) and moderate (> 50%) FiO2 with an oxygen flow rate of 15 [15-16] and 8 [7-9] L/min, respectively. Dyspnea score improved significantly after introduction of Bag-CPAP, and SpO2 increased. CONCLUSIONS: In vitro, Bag-CPAP exhibited the highest oxygen saving properties albeit had increased WOB. It was well accepted clinically and reduced dyspnea. Bag-CPAP may be useful to treat patients with acute respiratory failure in the field, especially when facing constraints in oxygen delivery.

Comparison of chest compression quality between the overlapping hands and interlocking hands techniques: A randomised cross-over trial.

BACKGROUND: Performing quality chest compressions is fundamental to the management of cardiopulmonary arrest. The aim of this study was to compare the efficacy of two hand positions: overlapping versus interlocking for performing chest compressions during cardiopulmonary arrest. METHODS: The HP2C (for Hands Position and Chest Compression) was a prospective, randomised, open-label, cross-over, single-centre study. Participants were recruited from the Emergency Medical Service (EMS) teams and the prehospital firefighter teams. They were randomised to start chest compressions either with overlapping or interlocking hands and then performed the other technique after a washout period. The judgement criteria were the overall chest compressions success score generated by software in accordance with ILCOR recommendations, the quality of compression, release, rate and subjective intensity measured with the Borg scale. RESULTS: A total of 100 participants were included in the study. The mean age of the caregivers was 38 ± 9.3 years. The median CPR score was 79.5% IQR [48.5-94.0] in the overlapping hands group and 71% IQR [38.0-92.8] in the interlocking hands group (p-value = 0.37). There was no significant difference for the other criteria, especially no difference in term of intensity of effort. However, there was a trend towards better results with overlapping hands. CONCLUSIONS: This study failed to demonstrate a difference in effectiveness between overlapping and interlocking hand chest compressions during cardiopulmonary resuscitation.

What is the true place of the SARS-CoV-2 rapid point-of-care antigen test in the hospital setting? Lessons learned from real life.

To assist in the clinical management of patients and to support infection control, we tested the use of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) point-of-care antigen test (AgPOC) for unplanned hospitalization, coupled with a nucleic acid amplification test (NAAT) using specimens collected at the same time upon arrival. The aim of this study was to assess the performance of the AgPOC in this specific use compared to NAAT for SARS-CoV-2 diagnosis, in the context of the low prevalence of infection. For 5 months (between two peaks in France of the SARS-CoV-2 pandemic), all patients admitted who undertook the AgPOC/NAAT paired tests were included in the study. AgPOC performances were determined considering the clinical status and the delay of symptoms onset. NAAT and AgPOC results were available for 4425 subjects. AgPOC results showed a homogeneous specificity (>97%) but a low sensitivity at 45.8%. Considering the national guidelines, sensitivity dropped to 32.5% in cases of symptomatic patients with symptoms older than 5 days or more. This study shows the poor performance of AgPOC for entry screening of patients in hospitals. AgPOC may represent a useful tool in the hospital setting only if the use is restricted to patients with consistent symptoms less than 4 days old.

A novel capnogram analysis to guide ventilation during cardiopulmonary resuscitation: clinical and experimental observations.

BACKGROUND: Cardiopulmonary resuscitation (CPR) decreases lung volume below the functional residual capacity and can generate intrathoracic airway closure. Conversely, large insufflations can induce thoracic distension and jeopardize circulation. The capnogram (CO2 signal) obtained during continuous chest compressions can reflect intrathoracic airway closure, and we hypothesized here that it can also indicate thoracic distension. OBJECTIVES: To test whether a specific capnogram may identify thoracic distension during CPR and to assess the impact of thoracic distension on gas exchange and hemodynamics. METHODS: (1) In out-of-hospital cardiac arrest patients, we identified on capnograms three patterns: intrathoracic airway closure, thoracic distension or regular pattern. An algorithm was designed to identify them automatically. (2) To link CO2 patterns with ventilation, we conducted three experiments: (i) reproducing the CO2 patterns in human cadavers, (ii) assessing the influence of tidal volume and respiratory mechanics on thoracic distension using a mechanical lung model and (iii) exploring the impact of thoracic distension patterns on different circulation parameters during CPR on a pig model. MEASUREMENTS AND MAIN RESULTS: (1) Clinical data: 202 capnograms were collected. Intrathoracic airway closure was present in 35%, thoracic distension in 22% and regular pattern in 43%. (2) Experiments: (i) Higher insufflated volumes reproduced thoracic distension CO2 patterns in 5 cadavers. (ii) In the mechanical lung model, thoracic distension patterns were associated with higher volumes and longer time constants. (iii) In six pigs during CPR with various tidal volumes, a CO2 pattern of thoracic distension, but not tidal volume per se, was associated with a significant decrease in blood pressure and cerebral perfusion. CONCLUSIONS: During CPR, capnograms reflecting intrathoracic airway closure, thoracic distension or regular pattern can be identified. In the animal experiment, a thoracic distension pattern on the capnogram is associated with a negative impact of ventilation on blood pressure and cerebral perfusion during CPR, not predicted by tidal volume per se.

Adaptation of ED design layout during the COVID-19 pandemic: a national cross-sectional survey.

BACKGROUND: The aim was to describe the organisational changes in French EDs in response to the COVID-19 pandemic with regard to architectural constraints and compare with the recommendations of the various bodies concerning the structural adjustments to be made in this context. METHODS: As part of this cross-sectional study, all heads of emergency services or their deputies were contacted to complete an electronic survey. This was a standardised online questionnaire consisting of four parts: characteristics of the responding centre, creation of the COVID-19 zone and activation of the hospital's emergency operations plan, flow and circulation of patients and, finally, staff management. Each centre was classified according to its workload related to COVID-19 and its size (university hospital centre, high-capacity hospital centre and low-capacity hospital centre). The main endpoint was the frequency of implementation of international guidelines for ED organisation. RESULTS: Between 11 May and 20 June 2020, 57 French EDs completed the online questionnaire and were included in the analysis. Twenty-eight EDs were able to separate patient flows into two zones: high and low viral density (n=28/57, 49.1%). Of the centres included, 52.6% set up a specific triage area for patients with suspected COVID-19 (n=30/57). Whereas, in 15 of the EDs (26.3%), the architecture made it impossible to increase the surface area of the ED. CONCLUSION: All EDs have adapted, but many of the changes recommended for the organisation of ED could not be implemented. ED architecture constrains adaptive capacities in the context of COVID-19.

Intrathoracic Airway Closure Impacts CO2 Signal and Delivered Ventilation during Cardiopulmonary Resuscitation.

RATIONALE: End-tidal CO2 (EtCO2) is used to monitor cardiopulmonary resuscitation (CPR), but it can be affected by intrathoracic airway closure. Chest compressions induce oscillations in expired CO2, and this could reflect variable degrees of airway patency. OBJECTIVES: To understand the impact of airway closure during CPR, and the relationship between the capnogram shape, airway closure, and delivered ventilation. METHODS: This study had three parts: 1) a clinical study analyzing capnograms after intubation in patients with out-of-hospital cardiac arrest receiving continuous chest compressions, 2) a bench model, and 3) experiments with human cadavers. For 2 and 3, a constant CO2 flow was added in the lung to simulate CO2 production. Capnograms similar to clinical recordings were obtained and different ventilator settings tested. EtCO2 was compared with alveolar CO2 (bench). An airway opening index was used to quantify chest compression-induced expired CO2 oscillations in all three clinical and experimental settings. MEASUREMENTS AND MAIN RESULTS: A total of 89 patients were analyzed (mean age, 69 ± 15 yr; 23% female; 12% of hospital admission survival): capnograms exhibited various degrees of oscillations, quantified by the opening index. CO2 value varied considerably across oscillations related to consecutive chest compressions. In bench and cadavers, similar capnograms were reproduced with different degrees of airway closure. Differences in airway patency were associated with huge changes in delivered ventilation. The opening index and delivered ventilation increased with positive end-expiratory pressure, without affecting intrathoracic pressure. Maximal EtCO2 recorded between ventilator breaths reflected alveolar CO2 (bench). CONCLUSIONS: During chest compressions, intrathoracic airway patency greatly affects the delivered ventilation. The expired CO2 signal can reflect CPR effectiveness but is also dependent on airway patency. The maximal EtCO2 recorded between consecutive ventilator breaths best reflects alveolar CO2.

New physiological insights in ventilation during cardiopulmonary resuscitation.

PURPOSE OF REVIEW: In the setting of cardiopulmonary resuscitation (CPR), classical physiological concept about ventilation become challenging. Ventilation may exert detrimental hemodynamic effects that must be balanced with its expected benefits. The risks of hyperventilation have been thoroughly addressed, even questioning the need for ventilation, emphasizing the need to prioritize chest compression quality. However, ventilation is mandatory for adequate gas exchange as soon as CPR is prolonged. Factors affecting the capability of chest compressions to produce alveolar ventilation are poorly understood. In this review, we discuss the conventional interpretation of interactions between ventilation and circulation, from the perspective of novel physiological observations. RECENT FINDINGS: Many patients with cardiac arrest exhibit 'intrathoracic airway closure.' This phenomenon is associated with lung volume reduction, impedes chest compressions to generate ventilation and overall limits the delivered ventilation. This phenomenon can be reversed by the application of small levels of positive end-expiratory pressure. Also, a novel interpretation of the capnogram can rate the magnitude of this phenomenon, contributing to clarify the physiological meaning of exhaled CO2 and may help assess the real amount of delivered ventilation. SUMMARY: Recent advances in the understanding of ventilatory physiology during CPR shows that capnogram analysis not only provides information on the quality of resuscitation but also on the amount of ventilation produced by chest compressions and on the total amount of ventilation.

Effect of Rocuronium vs Succinylcholine on Endotracheal Intubation Success Rate Among Patients Undergoing Out-of-Hospital Rapid Sequence Intubation: A Randomized Clinical Trial.

Importance: Rocuronium and succinylcholine are often used for rapid sequence intubation, although the comparative efficacy of these paralytic agents for achieving successful intubation in an emergency setting has not been evaluated in clinical trials. Succinylcholine use has been associated with several adverse events not reported with rocuronium. Objective: To assess the noninferiority of rocuronium vs succinylcholine for tracheal intubation in out-of-hospital emergency situations. Design, Setting and Participants: Multicenter, single-blind, noninferiority randomized clinical trial comparing rocuronium (1.2 mg/kg) with succinylcholine (1 mg/kg) for rapid sequence intubation in 1248 adult patients needing out-of-hospital tracheal intubation. Enrollment occurred from January 2014 to August 2016 in 17 French out-of-hospital emergency medical units. The date of final follow-up was August 31, 2016. Interventions: Patients were randomly assigned to undergo tracheal intubation facilitated by rocuronium (n = 624) or succinylcholine (n = 624). Main Outcomes and Measures: The primary outcome was the intubation success rate on first attempt. A noninferiority margin of 7% was chosen. A per-protocol analysis was prespecified as the primary analysis. Results: Among 1248 patients who were randomized (mean age, 56 years; 501 [40.1%] women), 1230 (98.6%) completed the trial and 1226 (98.2%) were included in the per-protocol analysis. The number of patients with successful first-attempt intubation was 455 of 610 (74.6%) in the rocuronium group vs 489 of 616 (79.4%) in the succinylcholine group, with a between-group difference of -4.8% (1-sided 97.5% CI, -9% to ∞), which did not meet criteria for noninferiority. The most common intubation-related adverse events were hypoxemia (55 of 610 patients [9.0%]) and hypotension (39 of 610 patients [6.4%]) in the rocuronium group and hypoxemia (61 of 616 [9.9%]) and hypotension (62 of 616 patients [10.1%]) in the succinylcholine group. Conclusions and Relevance: Among patients undergoing endotracheal intubation in an out-of-hospital emergency setting, rocuronium, compared with succinylcholine, failed to demonstrate noninferiority with regard to first-attempt intubation success rate. Trial Registration: ClinicalTrials.gov Identifier: NCT02000674.

Early inter-hospital transfer of patients with myocardial infarction without a doctor, paramedic or nurse on board: results from a French regional emergency care network.

BACKGROUND: In France, patients with acute coronary syndromes (ACS) are usually transferred from remote hospitals to percutaneous coronary intervention (PCI) centres in mobile intensive care units (MICUs) with on-board medical staff. They are then returned to the remote hospitals by MICU 48 h after PCI. However, MICU transportation and beds in a PCI centre are in short supply. Therefore, we investigated clinical outcomes among intermediate-risk ACS patients who were transferred in private ambulances without an on-board medic or paramedic; and returned to the remote hospital sooner after PCI. METHODS: In the French Alps, the RESURCOR network manages 'SCA-Alp' transfers using strict management protocols in ambulances with trained drivers and automatic external defibrillators, but without heart rhythm monitoring. We conducted an observational retrospective study that assessed outcomes (death and emergency return to the PCI centre within 48 h) in patients transferred using SCA-Alp. Our population comprised stabilized patients with ST-segment elevation myocardial infarction (STEMI) who returned to the remote hospital within 24-48 h of PCI, and uncomplicated patients with non-ST-segment elevation myocardial infarction (NSTEMI) within 24-72 h of symptom onset who come from and returned to ('round-trip') the remote hospital on the day of PCI (return < 12 h after PCI). RESULTS: Between 2010 and 2014, 101 STEMI and 490 NSTEMI patients were transferred using SCA-Alp. No adverse events occurred during transportation and no deaths were reported. Two of 591 patients (0.3% [95% confidence interval 0.1-1.4%]) experienced a stent thrombosis within 48 h of PCI that required a second urgent PCI; both were event free at 6-month follow-up. CONCLUSIONS: Inter-hospital transfer using SCA-Alp is associated with low event rates in intermediate-risk ACS patients, allowing a more streamlined use of medical facilities and freeing-up of beds in PCI centres.

Identifying Patients at Risk for Prehospital Sudden Cardiac Arrest at the Early Phase of Myocardial Infarction: The e-MUST Study (Evaluation en Médecine d'Urgence des Stratégies Thérapeutiques des infarctus du myocarde).

BACKGROUND: In-hospital mortality of ST-segment-elevation myocardial infarction (STEMI) has decreased drastically. In contrast, prehospital mortality from sudden cardiac arrest (SCA) remains high and difficult to reduce. Identification of the patients with STEMI at higher risk for prehospital SCA could facilitate rapid triage and intervention in the field. METHODS: Using a prospective, population-based study evaluating all patients with STEMI managed by emergency medical services in the greater Paris area (11.7 million inhabitants) between 2006 and 2010, we identified characteristics associated with an increased risk of prehospital SCA and used these variables to build an SCA prediction score, which we validated internally and externally. RESULTS: In the overall STEMI population (n=8112; median age, 60 years; 78% male), SCA occurred in 452 patients (5.6%). In multivariate analysis, younger age, absence of obesity, absence of diabetes mellitus, shortness of breath, and a short delay between pain onset and call to emergency medical services were the main predictors of SCA. A score built from these variables predicted SCA, with the risk increasing 2-fold in patients with a score between 10 and 19, 4-fold in those with a score between 20 and 29, and >18-fold in patients with a score ≥30 compared with those with scores <10. The SCA rate was 28.9% in patients with a score ≥30 compared with 1.6% in patients with a score ≤9 (P for trend <0.001). The area under the curve values were 0.7033 in the internal validation sample and 0.6031 in the external validation sample. Sensitivity and specificity varied between 96.9% and 10.5% for scores ≥10 and between 18.0% and 97.6% for scores ≥30, with scores between 20 and 29 achieving the best sensitivity and specificity (65.4% and 62.6%, respectively). CONCLUSIONS: At the early phase of STEMI, the risk of prehospital SCA can be determined through a simple score of 5 routinely assessed predictors. This score might help optimize the dispatching and management of patients with STEMI by emergency medical services.

Out-of-hospital traumatic cardiac arrest: an underrecognized source of organ donors.

Whereas the gap between organ supply and demand remains a worldwide concern, resuscitation of out-of-hospital traumatic cardiac arrest (TCA) remains controversial. The aim of this study is to evaluate, in a prehospital medical care system, the number of organs transplanted from victims of out-of-hospital TCA. This is a descriptive study. Victims of TCA are collected in the out-of-hospital cardiac arrest registry of the French North Alpine Emergency Network from 2004 to 2008. In addition to the rates of admission and survival, brain-dead patients and the organ transplanted are described. Among the 540 resuscitated patients with suspected TCA, 79 were admitted to a hospital, 15 were discharged alive from the hospital, and 22 developed brain death. Nine of these became eventually organ donors, with 31 organs transplanted, all functional after 1 year. Out-of-hospital TCA should be resuscitated just as medical CA. With a steady prevalence in our network, 19% of admitted TCA survived to discharge, and 11% became organ donors. It is essential to raise awareness among rescue teams that out-of-hospital TCA are an organ source to consider seriously.

Expeditious exclusion of acute coronary syndrome diagnosis by combined measurements of copeptin, high-sensitivity troponin, and GRACE score.

BACKGROUND: High-sensitivity troponin (HS-TnT) combined with copeptin have been proposed to expedite the diagnostic exclusion of acute myocardial infarction. The Global Registry of Acute Coronary Events (GRACE) has been validated and recommended by the European Society of Cardiology as a prognostic score in the management of acute coronary syndrome (ACS) without ST-segment elevation (non-ST+) on the electrocardiogram. Our study examined whether a low GRACE score (<108) combined with negative HS-TnT (<14 ng/L) and copeptin (<14 pmol/L) reliably exclude the diagnosis of non-ST+ ACS, including non-ST-segment elevation myocardial infarction and unstable angina. METHODS: This observational, prospective study included patients presenting with chest pain lasting <6 hours, consistent with non-ST+ ACS. Blood was collected early for measurements of copeptin and HS-TnT. The negative predictive value of combined copeptin, HS-TnT, and GRACE score was calculated in the diagnosis of non-ST+ ACS. The thresholds of positivity were 14 ng/L for HS-TnT, 14 pmol/L for copeptin and 108 for the GRACE score. RESULTS: Among 247 patients retained in the analysis, the diagnosis of ACS was made in 50 (20.4%), including 39 non-ST-segment elevation myocardial infarction and 11 unstable angina. The negative predictive value of combined HS-TnT, copeptin and GRACE score was 99%. CONCLUSION: A negative copeptin associated with a negative HS-TnT in a patient presenting with a low GRACE score expedited the diagnostic exclusion of non-ST+ ACS.

Overcrowding in the Dispatching Centre During the COVID-19 Crisis: Are Medical Students a Resource?

INTRODUCTION: In February, the emergence of COronaVIrus Disease 2019 (COVID - 19) in France made it necessary to rapidly adapt emergency and SAMU services in order to take care of many infected patients. To respond to the increase in the number of calls in the dispatch centers, reinforcements were necessary on the fronts of the Medical Regulation Assistants (ARM). The aim of this study was to assess the relevance of medical students' responses to first calls exclusively concerning COVID-19. METHODS: This prospective, observational cohort study was carried out at the University Hospital Centre (CHU) in Angers. Twenty medical students mostly in the 5th year were voluntarily enrolled in the first line COVID-19 call taker team. Calls on the 1st, 3rd, and 5th starting day for each medical student, and randomly selected calls from the experienced first-line call taker were listened to by a medical expert to assess the adequate level of prioritization and orientation (emergency physician or general practitioner). The percentage of agreement between the expert, students, and experienced first-line call handlers were assessed. All participants gave their free consent to participate. The study was approved by the Ethics Committee of Angers (N° 2020-48). RESULTS: From March 18 to April 23, 2020, 302 calls from medical students (n = 20 students) and 40 calls from experienced first-line call handlers were analyzed. The average prioritization agreement rate between the expert and students was 76.16% (95% Confidence Interval: 71.04 to 80.62%) (n = 230/302) compared to 87.50% (95% CI: 73.9 to 94.5%) (n = 45/50) for the experienced first-line call handlers (P = 0.15). Medical students took more time per call with an absolute difference of 2 minutes 16 seconds (P < 0.001). CONCLUSION: The lessons to be observed from this COVID-19 crisis are that in the early days of increasing calls heralding a strain on the healthcare system, support by medical students must be considered.

A new physiological manikin to test and compare ventilation devices during cardiopulmonary resuscitation.

Background: There is a lack of bench systems permitting to evaluate ventilation devices in the specific context of cardiac arrest. Objectives: The objective of the study is to assess if a new physiological manikin may permit to evaluate the performances of medical devices dedicated to ventilation during cardiopulmonary resuscitation (CPR). Methods: Specific CPR-related features required to reproduce realistic ventilation were implemented into the SAM (Sarthe Anjou Mayenne) manikin. In the first place, the manikin ability to mimic ventilation during CPR was assessed and compared to real-life tracings of airway pressure, flow and capnogram from three out of hospital cardiac arrest (OHCA) patients. In addition, to illustrate the interest of this manikin, ventilation was evaluated during mechanical continuous chest compressions with two devices dedicated to CPR: the Boussignac cardiac arrest device (B-card - Vygon; Ecouen France) and the Impedance Threshold Device (ITD - Zoll; Chelmsford, MA). Results: The SAM manikin enabled precise replication of ventilation tracings as observed in three OHCA patients during CPR, and it allowed for comparison between two distinct ventilation devices. B-card generated a mean, maximum and minimum intrathoracic pressure of 6.3 (±0.1) cmH2O, 18.9 (±1.1) cmH2O and -0.3 (±0.2) cmH2O respectively; while ITD generated a mean, maximum and minimum intrathoracic pressure of -1.6 (±0.0) cmH2O, 5.7 (±0.1) cmH2O and -4.8 (±0.1) cmH2O respectively during CPR. B-card allowed to increase passive ventilation compared to the ITD which resulted in a dramatic limitation of passive ventilation. Conclusion: The SAM manikin is an innovative model integrating specific physiological features that permit to accurately evaluate and compare ventilation devices during CPR.