MANAGEMENT OF CARDIAC ARREST With clear evidence that the quality and speed of compressions influence outcome, the emphasis of the 2010 guidelines focuses on steps that will increase performance. The 2010 guidelines also focus on the increasing body of evidence that support resuscitation science. The majority of cardiac arrest
to coronary and cerebral perfusion, the quality of CPR as determined by observers can range from good to very poor. Chest compression rates were inadequate during more than 50% of the time in a multicenter trial. Excessive ventilation interferes with survival by reducing cerebral blood flow. Early in resuscitation, chest compression without ventilation may actually be superior to chest compression with intermittent ventilation, given the residual oxygen in the functional residual capacity of the lung. Even the previously unchallenged axiom of “shock first” is challenged by evidence that defibrillation in the field is more often successful after three minutes of CPR than before. Interruption of chest compressions is another issue. Good evidence exists in an animal model that interruption of chest compressions reduces the effectiveness of resuscitation. Interruption in chest
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compressions interferes with “best possible” coronary perfusion. These interruptions are caused by defibrillation, ACLS maneuvers (intubation, central line placement, etc.) and even by unrecognized rescuer fatigue. Continuous compression without interruption has been shown to improve survival compared to tradition interrupted compression. Excessive ventilation is also associated with reduced effectiveness of resuscitation. Cerebral perfusion may be compromised by cerebral vasoconstriction from hypocapnia, and excessive lung volumes interfere with venous return due to increased mean intrathoracic pressure. Any compromise in cardiac filling further limits the cardiac output that can be achieved by chest compression. Ventilation should no greater than 8-10 breaths/ minute and just enough to produce visible chest excursion.
evidence occurs in adults. The causes of cardiac arrest are variable, although the majority are related to an arrhythmia that eliminates circulation to core organs. With witnessed arrest related to ventricular fibrillation (most common out-of-hospital) or pulseless ventricular tachycardia (most common in-hospital), the key elements to survival are effective chest compressions and early defibrillation. The traditional A-B-C sequence with initial attention to the airway, delays the initiation of chest compressions. Since perfusion is critical and oxygen is still present in the lungs for several minutes, starting the sequence with chest compressions is appropriate. This is particularly true because of the time and technical difficulty with detection of breathing and opening the airway. Going forward, the sequence will be C-A-B (Chest Compressions, Airway, Breathing). Early recognition is emphasized. The prior “Look, listen and feel” has been removed because time spent assessing breathing and searching for pulse delays the intubation of chest compression. In the vast majority of situations, resuscitation begins with 30 compressions. In the first 10 minutes of resuscitation, the focus is on eliminating causes of interruption of chest compressions. When rescue breathing is initiated, the time away from chest compression should be minimized. Although early defibrillation remains a critical element of effective ECC, there is emphasis in the 2010 guidelines to minimize the interval from last compression to shock and from shock to first compression to improve the success of the shock and overall survival. Pulse checks reduce chest compression fraction time and have been eliminated
«The majority of cardiac arrest evidence occurs in adults»
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