Circulation
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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.
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The finding that blood flow during external chest compression may be due to increased intrathoracic pressure, and the subsequent reporting of increased carotid blood flow with simultaneous ventilation and chest compression or with abdominal binding during CPR ignited a flurry of investigations into alternative approaches to CPR. A number of alterations of the conventional CPR technique were proposed, many resulting in improved hemodynamics when compared with standard CPR techniques in the same subject. However, some of the proposed methods increased cerebral blood flow but decreased myocardial perfusion. ⋯ Not all studies support the conclusion that blood flow during closed-chest compression is secondary to increased intrathoracic pressure. It is probable that in man there is a spectrum. In some individuals the predominant mechanism of blood flow during CPR may be cardiac and/or vascular compression, and in others flow may be secondary to an increased intrathoracic pressure.
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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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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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Current basic life support (BLS) protocols do not address the physiologic effects of accidental hypothermia in prehospital care. The extreme levels of bradycardia, bradypnea, and peripheral vasoconstriction that often accompany profound hypothermia may complicate the accurate diagnosis of cardiopulmonary arrest in the unmonitored patient. ⋯ This dilemma had led to disagreement among clinicians and researchers in hypothermia about prehospital care protocols for the severely hypothermic patient. This article reviews the controversy and recommends the application of a normal BLS protocol to hypothermic patients presenting in apparent cardiopulmonary arrest.