Biphasic defibrillators attempt to optimize trans-cardiac current flow by switching the direction of the current part way through shock delivery. High airway pressures can be generated if the tidal volume or inspiratory flow is excessive, predisposing to gastric inflation and subsequent risk of regurgitation and pulmonary aspiration. Peripheral venous cannulation is quicker, easier to perform and safer.
There is no evidence that the use of anti-arrhythmic drugs improves the rate of survival to hospital discharge. For those using monophasic defibrillators, please refer to Guidelines Letters to the editor.
Theophylline and related compounds block the effect of adenosine. If other staff are nearby, several actions can be undertaken simultaneously. When using masks without a connector, supplemental oxygen can be given by placing the tubing underneath one side and ensuring an adequate seal.
It may occur at any level, from the nose and mouth down to the trachea. Human studies of other vasopressor drugs alpha-methyl noradrenaline, endothelin are awaited.
Amiodarone is recommended by the International Liaison Committee on Resuscitation and has been adapted by the Resuscitation Council UK and the Advanced Life Support Group for use in paediatric advanced life support and advanced paediatric life support for the treatment of refractory supraventricular tachycardia. Include advice on clinical management while awaiting the arrival of more experienced staff.
Obstruction of the airway below the larynx is less common, but may arise from excessive bronchial secretions, mucosal oedema, bronchospasm, pulmonary oedema or aspiration of gastric contents. However, there are no reliable data to indicate that the incidence of aspiration is any more in cardiac arrest patients ventilated with bag-mask versus those that are ventilated via tracheal tube.
Ongoing CPR is not a contraindication to thrombolysis. In these studies, the definition of refractory VF was that it persisted following three attempts at defibrillation. More recently, extravascular devices can be implanted subcutaneously in the left chest wall, with a lead running to the left of the sternum. Research suggests that although MET calls may cause disruption to normal hospital routines and inconvenience to staff, no major patient harm follows.
Therefore, the optimal electrode position may not be the same for ventricular and atrial arrhythmias.
Refibrillation was not specifically addressed in guidelines. In patients with a shockable rythmn ventricular fibrillation and pulseless ventricular tachycardiathe first action would be to defibrillate as soon as possible followed by 2 minutes of CPR and the second defibrillation, after which adrenaline should be started and repeated every second cycle. Consider thrombolytic therapy when cardiac arrest is thought to be due to proven or suspected pulmonary embolus.
In the context of cardiac arrest from major trauma, consider bilateral thoracostomies for decompression of a suspected tension pneumothorax Section 4.
Conversely, if inspiratory flow is too low, inspiratory time will be prolonged and the time available to give chest compressions is reduced. Importantly, in the basic life support guidelines all reference to checking a pulse has been dropped on the basis that patients who are not responsive and not breathing normally are highly likely to be in arrest and will not be harmed by compressions if these are commenced unnecessarily.
Survival radiology for GPs. In some hospitals, the patient, and their family and friends, are also encouraged to activate the team. Further experimental models in humans and animals have shown an improved response to defibrillation in VF or VT following the administration of amiodarone LOE 7.
Transthoracic impedance varies during respiration, being minimal at end-expiration.