Objectives: To investigate if light sedation favorably affects subsequent patient mental health compared with deep sedation. Symptoms of posttraumatic stress disorder are common in patients after they have undergone prolonged mechanical ventilation and are associated with sedation depth.

Design: Randomized, open-label, controlled trial.

Setting: Single tertiary care center.

Patients: Adult patients requiring mechanical ventilation.

Interventions: Patients were randomized to receive either light (patient awake and cooperative) or deep sedation (patient asleep, awakening upon physical stimulation).

Measurements and Main Results: Self-reported measures of posttraumatic stress disorder, anxiety, and depression were collected at intensive care unit discharge and 4 wks later. The primary outcomes were symptoms of posttraumatic stress disorder, anxiety, and depression 4 wks after intensive care unit discharge.

A total of 137 patients were assigned to either the light (n = 69) or the deep sedation (n = 68) group. Seven patients withdrew consent and one patient was randomized in error, leaving 129 patients (n = 65 in light sedation and n = 64 in deep sedation) available for analysis. At the 4-wk follow-up, patients in the deep sedation group tended to have more posttraumatic stress disorder symptoms (p = .07); the deep sedation group had more trouble remembering the event (37% vs. 14%; p = .02) and more disturbing memories of the intensive care unit (18% vs. 4%; p = .05). Patients in the light sedation group had an average one day less being ventilated and 1.5 fewer days in the intensive care unit. There were no differences between the two groups in the occurrence of anxiety and depression, and also no difference in mortality or in the incidence of adverse events.

Conclusions: These data suggest that a strategy of light sedation affords benefits with regard to reduction of intensive care unit stay and duration of ventilation without negatively affecting subsequent patient mental health or patient safety.