[Intraoperative awareness].

Abstract

The first cases of general anesthesia were already cases with awareness. Until today, case reports of patients with awareness are published. These published cases are likely to be the top of the iceberg, as most patients with postoperative recall do not inform their anesthesiologist. Incidence of awareness with recall is between 0.1 and 0.2 %. In a large multicenter-study, incidence of recall was 0.1 % without, and 0.18 % with the use of muscle relaxants. The risk is increased with decreased doses of anesthetics, e.g. in patients with hemodynamic instability (trauma cases), patients undergoing cesarean section or cardiac surgery. Intraoperative awareness does not necessarily cause explicit (conscious) memory. Even in the absence of explicit memory, implicit (unconscious) memory can still have consequences for the patient. In the worst case, it can cause post-traumatic stress disorder. There is doubt whether patients may profit from positive suggestions given during intraoperative awareness. Recommendations to administer benzodiazepines to prevent explicit memory must be reconsidered. Complete neuromuscular block should be avoided whenever possible. If a patient is thought to be aware, he should be contacted, his situation should be explained and affirming comments should be given until consciousness is lost again. Postoperative visit should include questions about awareness and recall. The anesthetist should not disbelieve reported recall. Explanation of what had happened and referral to an experienced psychologist must be offered. Thus, the incidence of severe sequelae should decrease.