Outcomes
respiratory insufficiency, cardiac arrest, allergic reaction, apnoea
CIRCULATORY ARREST, ALLERGIC REACTION, RESPIRATORY INSUFFICIENCY, CARDIAC ARREST, COMPLICATIONS
The primary outcome with respect to the non-inferiority of the tele-group was the frequency of four predefined intervention-related AEs during EMS treatment with suspected causality to the group assignment, as one would expect benefit or minimising risk having an EMS physician on scene.The predefined AEs, which were not the original reason for the emergency call, were chosen by the authors because they represent the most common AEs associated with drug therapy in the EMS and comprised the following three new immediate AEs: (i) allergic reaction (documented in the free text or indicated by the use of anti-allergic drugs after any treatment by the EMS team); (ii) blood pressure decrease (necessity of vasopressors); and (iii) respiratory insufficiency (decrease in peripheral oxygen saturation < 90%, or need for assistive, manual or controlled ventilation). Further, it comprised one new AE with a time lag of 24 h, in order to capture also delayed complications possibly resulting from not guideline-conform treatment of the EMS: (iv) cardiac arrest within 24 h of the intervention. The term “intervention-related” covered beside wrong treatments (e.g. iatrogenic allergic reaction because of inadequate survey of medical history; iatrogenic blood pressure drop, apnoea or respiratory insufficiency after wrong drug dosage or selection; or circulatory arrest after wrong drug dosage, or wrong hospital referral) also the cases where the respective EMS did not provide any treatment. An independent clinical endpoint committee (CEC) judged whether the reported AEs were suspected to have occurred because of group assignment based on blinded data (see also Additional file Secondary outcomes regarding the superiority hypotheses for the tele-group were analysed by means of the EMS files and comprised the guideline-conform medical history survey, treatment and documentation quality, AEs independent of the EMS care used, and the necessity of a physician for the EMS operation. For further details on outcome measures, see Additional file 