Circulation
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Cardiopulmonary resuscitation in children is not well studied; many of the current recommendations for advanced pediatric life support (APLS) are based on anecdotal experience rather than scientific study. The following are unique issues in APLS requiring a consensus decision: What are the best methods of vascular access and of drug delivery and dosages? What constitutes minimal paramedic training and equipment? There are also many shared controversies between APLS and ACLS, including the use of calcium, epinephrine vs isoproterenol, methoxamine, and bicarbonate. This article presents the scientific basis for these controversial issues and highlights areas where information is lacking. A discussion of these questions generated a consensus on some issues and hopefully will stimulate further study to answer the questions that were raised.
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Blood flow during closed-chest CPR may result from variations in intrathoracic pressure rather than selective compression of the cardiac ventricles. During chest compression, the thoracic and abdominal cavities are subjected to positive pressure fluctuations. It has been suggested that compression of the abdomen may improve left heart outflow during CPR by limiting diaphragmatic movement or improving venous return. ⋯ Selective abdominal binding also increases systolic pressures during CPR but does not improve subdiaphragmatic venous return. Although abdominal binding may increase common carotid flow, it has not been shown to improve cerebral or myocardial perfusion when compared with conventional CPR alone. These CPR adjunct techniques have not been shown to improve outcome from cardiac arrest and should remain experimental until further well-designed studies addressing regional vital organ flow and outcome of resuscitation are performed.
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The addition of interposed abdominal compressions (IACs) to otherwise standard CPR enhances artificial circulation both in anesthetized dogs with ventricular fibrillation and in electrical models of the circulation that demonstrate fundamental mechanisms generating flow. Manual abdominal compressions cause both central aortic and central venous pressure pulses but, because of differences in venous and arterial capacitance, the former are usually greater than the latter. ⋯ However, no study has demonstrated that IAC-CPR improves either short- or long-term survival after cardiac arrest in man. Accordingly, the method remains experimental and cannot be recommended for basic life support at the present time.
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Three forms of treatment are available for patients with paroxysmal supraventricular tachycardia (PSVT): nonpharmacologic, pharmacologic, and electrical. Nonpharmacologic treatments increase vagal tone and include the traditional carotid sinus massage and Valsalva maneuver as well as head-down tilt, activation of the diving reflex, and use of the pneumatic antishock garment. ⋯ Patients with antegrade accessory pathway conduction (such as those with Wolff-Parkinson-White syndrome) and a history of atrial fibrillation should be treated with intravenous procainamide if they are hemodynamically stable and with synchronized electrical countershock if they are hemodynamically unstable. Synchronized electrical countershock is the treatment of choice for hemodynamically unstable patients.
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Review
Special resuscitation situations: near drowning, traumatic injury, electric shock, and hypothermia.
Special resuscitation situations are cardiopulmonary arrests requiring modification or extension of conventional life support techniques. Significant controversy exists with regard to several aspects of special resuscitation, including whether or not there is a need to clear the airway of a near-drowning victim with the Heimlich maneuver and whether CPR should be initiated in an unmonitored hypothermic patient showing no signs of life. The previous standards and guidelines almost entirely neglected the management of cardiac arrest due to traumatic injury. The conference panel on Special Situations recommended that: the Heimlich maneuver should only be performed on near-drowning victims when the rescuer suspects that foreign matter is obstructing the airway or the victim fails to respond appropriately to mouth-to-mouth ventilation, further investigation is needed to better define the need for, the risks of, and the timing of the Heimlich in the near-drowning victim, there should be an expanded section in the standards and guidelines describing the differences in the management of a victim whose cardiac arrest is due to traumatic injury, CPR is indicated and should be done on a pulseless, unmonitored hypothermic patient in the field, but that a longer time to check for a pulse (up to one minute) may be required, and guidelines that the panel proposed be used for management of the underwater submersion victim in cardiac arrest.