Out-of-hospital cardiac arrest: the teaching of experience at the SAMU of Lyon.

Because of the improvement resuscitation techniques have shown since the 1960s and because of the development of the out-of-hospital medical care, a cardiac arrest is no longer synonymous with death in every case. However the cardiac arrest resuscitation is only relevant if its adverse consequences can be limited. That is mainly the neurological after-effects and the cellular anoxia. Therefore, the "Service d'Aide Medicale Urgente" (SAMU) of Lyon has been concentrating its research aiming at: (a) Shortening the duration of cardiopulmonary resuscitation to limit the cerebral anoxia. (b) Analysing and treating some of the causes responsible for the aggravation of anoxia. On the basis of several studies in Lyon, here are some suggestions: (1) The use of high doses of epinephrine that unables a better percentage of primary recoveries (47.5% vs. 39%) (P less than 0.05) and secondary recoveries (21.3% vs. 14.8%) (P less than 0.01) without modifying the qualitative survival at long term. (On the basis of: 5 mg intravenous bolus repeated every 3 min in case of asystole instead of 1 mg every 5 min as it is usually recommended). (2) The choice of a peripheral intravenous line instead of a central intravenous line each time it is possible for the administration of drugs since it is as efficient as the second one. (40.7% vs. 33.4%) (P:NS). (3) The alkalinisation of the prolonged cardiac arrest in order to keep the acid-base balance. Most of the survivors show a pH equal or superior to the normal standard. (On the basis of 1 mmol/kg of sodium bicarbonate if the cardiac arrest lasts for more than 10 min). (4) The abolition of the dextrose solution as maintaining infusion the patients who are in a "coma depasse" (brain death) after the resuscitation have an average glycemia superior to the survivors without after-effects. (19.7 vs. 14.8 mmol/l) (P less than 0.05). (5) The monitoring at once at the hospital of the intra-cranial pressure. It reveals the frequency of high pression at an early stage (superior to 15 mmHg in 51.1% of the cases) and the absence of favourable evolution in case of high intracranial pressure. At the moment the absence of consequences on the ICR of a calcium entry blocker (Nimodipine) is being studied. The first results do not seem to show any improvement of the cerebral survival. (6) The prophylactic treatment of septicemia with intestinal origin since they occur frequently and prove to be fatal.