INTRODUCTION:Our goal was to evaluate the details and management of cardiac arrest (CA) occurring in the working environment. MATERIALS AND METHODS:We conducted a 10-year retrospective study based on the medical records of the Garches mobile intensive care unit. CA occurring in the workplace ("Inside W." group) was matched with two CA outside the workplace ("Outside W." group), with regard to sex, age and year of occurrence. The Chain of Survival and prognosis factors were analysed in a bi-multivariate analysis. RESULTS:From 1993 to 2002, 72 CA were included in the "Inside W." group, with 79% arising from suspected cardiac aetiology (there was a similar proportion in the "Outside W." group). Some variables in the cardiac aetiology patients were higher in the "Inside W." group compared to the "Outside W." group (P < 0.05): early external chest compression [(ECC), 37%, n = 20 versus 16%, n = 16)] and ventricular fibrillation as initial recorded rhythm (40%, n = 33 versus 16%, n = 16). The proportion of use of automated external defibrillator (AED) was similar in the two groups. The workplace was not associated with a better outcome, with 9% patients discharged alive compared to 4% n = 6, P > 0.05. Early ECC and defibrillation attempted with an AED were associated with patients discharged alive from the intensive care unit in a multivariate analysis (P < 0.05), but not the workplace and cardiac aetiology. CONCLUSION:Although our study did not support that concept that the workplace was a safer place, there was a better chain of survival for CA applied within workplace settings. Basic Life Support teaching and installation of AEDs could be helpful, though further cost-effectiveness studies are needed.

Nous rapportons l'étude de 11 ventilateurs d'anesthésie équipés d'un circuit de réinhalation et dont les performances mécaniques ont été évaluées. Ces appareils étaient les suivants : Excel et Modulus II Plus (Ohmeda), Ventilator 710 et Servo Anesthesia Circle 985 (Siemens), Jollytronic et Elsa (Engström), SA2/RA2 et Cicero (Dräger), ABT 4300 (Kontron Instruments), Monnal A et Alys (Taema). Les essais ont passé en revue la fiabilité de la spirométrie, l'influence du débit de gaz frais sur le volume délivré et la spirométrie mesurée, et la résistance inspiratoire du circuit lors d'une simulation de la ventilation spontanée. Les performances étaient bonnes dans des conditions de charge normale. Inversement, certains appareils ne parvenaient pas à maintenir la totalité de leurs performances lorsque l'on simulait des situations plus difficiles (SA2/RA2, Excel, Modulus, Monnal, Ventilator 710, Elsa, ABT 4300). La résistance inspiratoire en ventilation spontanée était toujours inférieure à 3,6 cmH2O · 1−1 · s−1. L'augmentation du débit de gaz frais induisait une augmentation de la ventilation délivrée sur six appareils. En conclusion, dans des conditions extrêmes de charge respiratoire et sur certains respirateurs, il est important d'augmenter le volume courant, afin de maintenir une ventilation minute correcte. Néanmoins, les appareils qui voient le temps inspiratoire augmenter sous l'effet de la charge ne sont pas accessibles à une correction de ce type.Eleven anaesthesia ventilators were instrumentally tested under various conditions. They included : Excel and Modulus II Plus (Ohmeda) ; 710 and Servo anaesthesia circle 985 (Siemens) ; Jollytronic (Soxil) and Elsa (Engström) ; SA2 and Cicero (Dräger) ; ABT 4 300 (Kontron) ; Monnal A and the prototype Alys (Taema). The test circuit comprised a two compartment model lung, a pneumotachograph, a pressure gauge in the « airway . The volume was calculated as the integral of flow rate. Each machine was calibrated by the firms' technicians. Before each test, the pneumotachograph was calibrated using a 11 air syringe and the pressure gauge with a 5 cm water column. Each machine ventilated the model lung for 30 min before starting the tests. There were five tests : 1) reliability of the machine's spirometer, 2) reliability of the ventilation rate, 3) reliability of pressure measurements, 4) effect of increasing fresh gas flow on spirometry, 5) effect of increasing downstream resistances. In usual simulated ventilatory conditions, all the machines accurately delivered the setted ventilation and spirometric measurements were with minimal error only. Several ventilators (SA2, Excel, 710, Elsa, ABT 4 300) did not succeed in maintaining their performances when compliance was strongly decreased or resistance of the test lung notably increased. Resistance in the circuit during simulated spontaneous ventilation was < 3.6 cmH2O · l−1 · s−1. Increasing fresh gas flow raised the minute volume delivered in six ventilators. It is concluded that, during extreme ventilatory conditions, the inspired volume must be adjusted so as to maintain the inspired tidal volume. However, ventilators which increase inspiratory time in response to an increased mechanical load cannot be adjusted by this way.