ABSTRACT
BACKGROUND: Recognition of out-of-hospital-cardiac arrests (OHCAs) at emergency medical communication centres is based on questions of OHCA symptoms, resulting in 50-80% accuracy rates. However, OHCAs might be recognized more promptly using 'rhythm-based' recognition, whereby a victim's cardiac rhythm is recorded with mobile phone technology that analyses and transmits recordings to emergency medical communication centres for further interpretation. OBJECTIVE: To examine whether the quality of normal cardiac rhythm and the rhythm with the best prognosis in OHCA, ventricular fibrillation (VF), is sufficient for 'rhythm-based' OHCA recognition when recorded within a mobile phone-sized device. PATIENTS AND METHODS: mid-sternum within an area the size of a mobile phone and analysed by automated external defibrillator (AED) software and two cardiologists. The rhythms were categorized as shockable or nonshockable. The cardiologists assessed the quality of the recordings. RESULTS: The AED software correctly analysed all normal rhythms and 15 of 22 VF rhythms. The VF duration was too short for automatic detection in seven cases. The cardiologists analysed all the normal rhythms and VF sequences correctly and graded them as high quality. CONCLUSION: The recordings of normal ECG rhythm and VF within an area the size of a mobile phone are of sufficient quality and could be used in 'rhythm-based' OHCA recognition. The VF period was too short for an accurate analysis by the AED software in some cases.
Subject(s)
Cell Phone , Defibrillators , Electrocardiography/methods , Out-of-Hospital Cardiac Arrest/diagnostic imaging , Ventricular Fibrillation/diagnostic imaging , Aged , Emergency Medical Services , Female , Humans , Japan , Male , Middle Aged , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/therapy , Risk Assessment , Sampling Studies , Sensitivity and Specificity , Severity of Illness Index , Statistics, Nonparametric , Ventricular Fibrillation/diagnosis , Ventricular Fibrillation/therapyABSTRACT
OBJECTIVE: Recognition of cardiac arrest (CA) during an emergency call leans on questions concerning CA symptoms and is correct in 50-83% of cases. If the heart rhythm could be recorded and analysed over a mobile phone or transmitted during the emergency call to the dispatch centre and analysed there, using software identical to one in an automated external defibrillator (AED), CA recognition could be more prompt. We investigated whether an AED can correctly analyse normal heart rhythms recorded within an area the size of a mobile phone. METHODS: Bipolar ECG signal was recorded using an AED in 20 healthy volunteers in four different positions during rest and muscle tension with small pads in an area the size of a mobile phone. Recordings obtained with standard pads in standard positions served as the reference. The recorded ECGs were analysed with an AED and by two cardiologists and categorized as shockable or nonshockable. RESULTS: All analyses were correct when the recordings were performed vertically at the midsternum level. Horizontally at this level, the AED made correct analyses in 95 and 65% of cases and the cardiologists in 100 and 88% of cases at rest and during muscle tension, respectively. In the lateral positions only the analyses by cardiologists partly reached 100% sensitivity. The analysis time of the AED was 7 s in all positions. CONCLUSION: ECGs can be analysed promptly with an AED within an area the size of a mobile phone. The most reliable recording position was vertical at the midsternum level.
Subject(s)
Defibrillators , Electrocardiography/methods , Adult , Electrocardiography/instrumentation , Feasibility Studies , Female , Heart/physiology , Humans , Male , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/physiopathologyABSTRACT
The optimal treatment for severe accidental hypothermia is cardiopulmonary bypass because this offers the most rapid rate of rewarming. However, cardiopulmonary bypass therapy is not available in every hospital. In these circumstances, rewarming has to be achieved with other methods. We present a patient who was successfully rewarmed with thoracic lavage after he had been found with a core temperature of 21°C and asystole.
