Over the last years, Automatic External Defibrillators (AED) are increasingly used in the case of an out-of-hospital cardiac arrest (OHCA). In the Netherlands, an AED is placed before arrival of an ambulance in 60% of the OHCA’s. This means that the true initial rhythm is recorded by the AED in the majority of the cardiac arrest patients. And this initial rhythm can stay unknown for the receiving hospital. This can prevent the admitting hospital to give the right treatment to the patient.
When admitting an OHCA patient, we are used to ask what the initial heart rhythm was of the patient when the ambulance arrived at the scene. The initial rhythm gives an indication on the prognosis, but more importantly, will have significant impact on the evaluation and treatment of that patient. For example, a patient with a shockable rhythm will more likely to be taken for an emergency percutaneous coronary intervention (PCI) and implantable cardioverter defibrillator (ICD). But when an AED is used, the initial rhythm observed by the ambulance personnel could have been changed by the defibrillation(s) by the AED. In this way, it can be uncertain what the true initial rhythm was.
It is not always clear whether or not the AED gave a defibrillation. When people are suddenly confronted with a cardiac arrest, stress will have significant impact on their senses, judgement, memory and performance. It is possible that a bystander didn’t see the AED provider giving a shock to the patient and gives the ambulance crew a handover that the AED did not give a shock. Laypersons could have forgotten that they pushed the shock button. Or the ambulance crew did not speak to the person who used the AED. Some AED manufacturers have a screen with information on the defibrillations given by the AED. This information is however lost when the AED is switched off, which can happen when the AED is removed to connect the patient to the monitor of the ambulance service.
Although it can be difficult for ambulance crew to get to know whether or not the AED gave one or more defibrillations, it is important to try. When the AED has a screen with info on the defibrillations, keep it turned on and check whether or not the AED gave a shock. When the AED does not provide you with this information, ask the person who connected the AED to the patient. Try to verify the answers with other persons who were present at the resuscitation.
As professionals who receive cardiac arrest patients, we are faced with this organizational challenge. We have to think of a system in which we can retrieve the essential information from the AED. There are different options to achieve this; The AED can be transported to the hospital along with the patient. In that case, the there has to be hard- and software available in the hospital to get the info from the AED. And efforts should be made to get the AED back to the owner. An alternative is to send someone to the location of the AED after the resuscitation. Possibly, the ambulance service could take on this role.
There are recent developments that AED’s can send data to a server through wireless (3G or WiFi) network. We should make efforts to retrieve this information to get it to the treating physician. That will sure help to solve this problem. Until then, we should do our best to retrieve the essential information on the rhythm and defibrillations from the AED. Make sure to organize this process with everyone involved in prehospital resuscitation. It can make a difference to your patient.