Resuscitation
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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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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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Cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) skills competency can be tested using a checklist of component skills, individually graded "pass" or "fail." Scores are typically calculated as the percentage of skills passed, but may differ from an instructor's overall subjective assessment of simulated CPR or AED adequacy. ⋯ Our findings suggest that instructors in public CPR and AED classes may tend to down-weight process skills and to excuse step sequencing errors when evaluating CPR and AED skills subjectively for overall proficiency. Testing methods that relate classroom performance to actual performance in the field and to clinical outcomes require further research.
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To determine the error of measurement in pulse oximetry with a decreased arterial perfusion and to identify a systolic pressure threshold for (1) initial detection and (2) a reliable reading of oxygen saturation. ⋯ Pulse oximetry is reliable with a systolic blood pressure > 80 mmHg. The lower the BP, the lower the pulse oximetry readings leading to a bias of up to -45%.
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Comparative Study
Body surface mapping versus the standard 12 lead ECG in the detection of myocardial infarction amongst emergency department patients: a Bayesian approach.
To determine if body surface mapping (BSM) is better than the standard 12 lead ECG in the diagnosis of acute myocardial infarction amongst emergency department patients. ⋯ BSM has a higher sensitivity, but a lower specificity for the diagnosis of myocardial infarction.