Resuscitation
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Survival from ventricular fibrillation and asystole is influenced by variables measured during resuscitation that affect both immediate survival and discharge from hospital. These variables have been used to develop a formula to calculate an individuals chances of immediate survival and hospital discharge. It has allowed this heterogenous group to be subdivided into groups which can be compared both within and between institutions for the purposes of audit and evaluation of resuscitation protocols. ⋯ The increase in the numbers of survivors improved the reliability (area under the receiver operator curve (ROC) improved from 0.79 to 0.83) of the index for predicting hospital discharge. Addition of the clinical variables of conscious state, respiratory state, blood pressure and pulse rate improved the prognostic index further to an ROC area of 0.86. This ensures that the predictive power of the new index is now highly reliable for predicting hospital discharge after successful resuscitation from ventricular fibrillation and asystole.
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After prolonged cardiac arrest and reperfusion, global cerebral blood flow (gCBF) is decreased to about 50% normal for many hours. Measurement of gCBF does not reveal regional variation of flow or permit testing of hypotheses involving multifocal no-flow or low-flow areas. We employed the noninvasive stable Xenon-enhanced Computerized Tomography (Xe/CT) local CBF (LCBF) method for use in dogs before and after ventricular fibrillation (VF) cardiac arrest of 10 min. ⋯ Trickle flow areas (LCBF less than 10 ml/100 cm3 per min) not present prearrest, were interspersed among regions of low, normal, or even high flow. Regions of 125-500 mm3 with trickle flow or higher flows, in different areas at different times, involving deep and superficial structures migrated and persisted to 6 h, with gCBF remaining low. These preliminary results suggest: no initial no-reflow foci (less than 10 ml/100 cm3 per min) larger than 125 mm3 persisting through the initial global hyperemic phase; delayed multifocal hypoperfusion more severe than suggested by gCBF measurements; and trickle flow areas caused by dynamic factors.
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Case Reports
Evidence for the 'cardiac pump theory' in cardiopulmonary resuscitation in man by transesophageal echocardiography.
There are two theories to explain the mechanism of blood flow during cardiopulmonary resuscitation: The 'Cardiac Pump Theory' and the 'Thoracic Pump Theory'. We have performed transesophageal echocardiography during the resuscitation of a patient with cardiopulmonary arrest. By this method we could study the motion of the aortic, mitral and tricuspid valves and the changes in ventricular size during cardiopulmonary resuscitation in man. ⋯ Short interruption of cardiopulmonary resuscitation to test for spontaneous heart action lead to echocontrast in all four heart chambers through stasis of blood, which resolved on continuation of cardiopulmonary resuscitation. This 'washing out' phenomenon enables visualization of blood flow through the aortic valve during compression, and through the mitral valve during relaxation. These observations favour the Cardiac Pump Theory as the predominant hemodynamic principle of blood flow during cardiopulmonary resuscitation in man.
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In order to firstly evaluate the efficacy of flumazenil in reversing benzodiazepine-induced sedation because of drug overdose and secondly to register adverse events, 13 patients admitted to the intensive care unit because of drug intoxication, were given flumazenil intravenously to a maximum of 1.0 mg. Sedation state was scored on a modified Glasgow Coma Scale and arterial blood pressure, heart rate and arterial blood gases were recorded before and after flumazenil was given, and every 30 min for 2 h. Results showed that flumazenil reversed the sedation due to benzodiazepines effectively increasing the coma score significantly (P less than 0.005). ⋯ Six patients became resedated, only one needed additional flumazenil. One patient developed a hypertensive crisis after flumazenil was given as a result of the unmasking of an untreated hypertension. Another patient aspirated gastric content to the trachea during resedation and needed respiratory support.
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The optimal dose of epinephrine in human cardiac arrest remains an area of continuing controversy. Apart from animal data some anecdotal reports in humans suggest that the dose currently recommended by the AHA may be insufficient for resuscitation of spontaneous circulation during prolonged cardiac arrest (CA). Since 1982, 1610 CA patients registered in Bruges have been evaluated under the following variables: prolonged survival (class 3 CPCR successes); solely restoration of spontaneous circulation (ROSC): class 2a, 2b and 3); epinephrine dose used during cardiopulmonary resuscitation (CPR); duration of advanced life support (ALS) and duration of complete CA. ⋯ E. M.) for the total population (n = 1724) was 2.53 +/- 0.06 mg; for patients since March 1989 (n = 114) this number was 5.58 +/- 0.36 mg. In contrast to the period before March 1989, we found a non-significant positive correlation between the survival of class 3 and epinephrine dose by limiting the influence of CPR times in the asystole and electromechanical dissociation (EMD) arrest groups.