Cardiopulmonary Resuscitation: The Science Behind the Hands
Highlights
- ATP concentrations declined significantly over time, reaching concentrations that were less than half of normal after only 5 min of unsupported VF (figure 1).5 A corresponding time-dependent diminution in the amplitude and apparent coarseness of the VF waveform has also been observed in clinical VF, such that in its late stages the arrhythmia is often indistinguishable from asystole (figure 2). It is likely that the declining vigour of the VF waveform is a result of consumption of high-energy phosphate molecules resulting in a progressively energy-depleted myocardium. Another possible expression of this energy-depleted state is the heart’s poor contractile function after a protracted period of VF has been terminated by shock. This often results in asystole or pulseless electrical activity (View Highlight)
- After pausing chest compressions, CPP quickly decreases to zero and can take upwards of 15 or more compressions to achieve the same magnitude to that present before the pause (View Highlight)
- The AHA cautions that the lower cardiac output during CPR requires less ventilation than normal—and that 10 breaths per minute, each sufficient to make the chest rise, are adequate (View Highlight)