POCD can markedly impair postoperative recovery. The findings of pertinent studies performed to date are difficult to generalize because of heterogeneous patient groups and different measuring techniques and study designs. Further investigation is needed to determine which test instruments are best for clinical use and which preventive strategies might lessen the incidence of POCD.

Critically ill patients reported a high incidence of recall for unpleasant events, which they thought to have taken place before they regained consciousness. The patients, who stayed longer than 24 h at the ICU, indicated vivid memory for nightmares and hallucinations. Further studies are suggested to evaluate: 1) whether there is an impact of the present findings on outcome; and 2) whether clinical scores for sedation or neurophysiological monitoring help to define the exact time, when recall happens, in order to guide therapeutic intervention.

Strategies for avoiding awareness phenomena under anesthesia include the training of staff to know about the problem and, specifically, the use of benzodiazepines, the avoidance of muscle relaxants if possible, and shielding the patient from excessive noise. EEG monitoring is effective but provides no guarantee against awareness. If awareness under anesthesia occurs despite these measures, the patient must be given expert, interdisciplinary treatment as soon after the event as possible in order to minimize its potential sequelae.

A multimodal integration of both standard monitoring and electroencephalographic parameters may more precisely reflect the level of anesthesia compared with monitoring based on one of these aspects alone.