Incidence of recall, nightmares, and hallucinations during analgosedation in intensive care.

OBJECTIVE

To define the incidence of recall and dreams during analgosedation in critically ill patients.

DESIGN

Prospective clinical study.

SETTING

Anaesthesiological intensive care unit (ICU) in a university hospital.

PATIENTS AND

PARTICIPANTS

Two hundred and eighty-nine critically ill patients, who either arrived intubated and sedated at the ICU or required intubation, mechanical ventilation, and sedation during their ICU stay.

INTERVENTIONS: none.

MEASUREMENTS AND

RESULTS

The patients were interviewed 48-72 h after discharge from the ICU. By a structured interview they were asked whether they recalled any event before they had regained consciousness at the ICU. Moreover they were asked for dreams. Descriptive statistics: 64.7% of all patients did not recall any event, before they regained consciousness. However, 17% ( n=49) of all patients indicated that they remembered the tracheal tube or being on the ventilator, before they woke up. Some patients (21.1%) reported dreams or dreamlike sensations. Some patients (9.3%) recalled nightmares, while 6.6% reported hallucinations.

CONCLUSIONS

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.