Resuscitation
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During CPR, an inspiratory time of 2 s is recommended when the airway is unprotected; indicating that approximately 30% of the resuscitation attempt is spent on ventilation, but not on chest compressions. Since survival rates may not decrease when ventilation levels are relatively low, and uninterrupted chest compressions with a constant rate of approximately 100/min have been shown to be lifesaving, it may be beneficial to cut down the time spent on ventilation, and instead, increase the time for chest compressions. In an established bench model of a simulated unprotected airway, we evaluated if inspiratory time can be decreased from 2 to 1 s at different lower oesophageal sphincter pressure (LOSP) levels during ventilation with a bag-valve-mask device. ⋯ Total cumulative stomach inflation volume over constantly decreasing LOSP levels with an inspiratory time of 2 s versus 1 s was higher (6820 ml versus 5920 ml). In conclusion, in this model of a simulated unprotected airway, a reduction of inspiratory time from 2 to 1 s resulted in a significant increase of peak airway pressure and peak inspiratory flow rate, while lung tidal volumes remained clinically comparable (up to approximately 15% difference), but statistically different due to the precise measurements. Theoretically, this may increase the time available for, and consequently the actual number of, chest compressions during CPR by approximately 25% without risking an excessive increase in stomach inflation.
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Recent data suggest that generation of negative intrathoracic pressure during the decompression phase of CPR improves hemodynamics, organ perfusion and survival. ⋯ Incomplete chest wall recoil during the decompression phase of CPR increases endotracheal pressure, impedes venous return and decreases mean arterial pressure, and coronary and cerebral perfusion pressures.
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Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4-10 min). ⋯ The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.
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Measuring different intervals during cardiopulmonary resuscitation is a key element of resuscitation performance. For accurate time measurements, the internal clocks of automated external defibrillator (AEDs) need to be synchronized with the dispatch centre time. ⋯ Synchronisation of AED clocks is not widespread in Finland. Instructions to synchronize have been issued in a minority of EMS systems. Despite this, time deviations are large, and erroneous times are recorded.
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Mild therapeutic hypothermia has shown to improve neurological outcome after cardiac arrest. Our study investigated the efficacy and safety of cold simple intravenous infusions for induction of hypothermia after cardiac arrest preceding further cooling and maintenance of hypothermia by specialised endovascular cooling. ⋯ Our results indicate that induction of mild hypothermia with infusion of cold fluids preceding endovascular cooling is safe and effective.