Objective  

To determine the frequency, characteristics and outcomes of severe agitation among ventilated medical intensive care unit (MICU) patients.

Design  

Prospective cohort study.

Setting  

Eighteen-bed MICU in 964-bed tertiary care center.

Patients  

All ventilated patients, aged 18 years or older and admitted for more than 24 h between January 1, 2001 and May 8, 2001.

Interventions  

None.

Measurements  

Data were collected daily by concurrent chart abstractions. Variables included sociodemographic, clinical, laboratory, pharmacologic and non-pharmacologic interventions, ventilator settings and adverse events. Severe agitation, the main outcome variable, was defined as two or more Motor Activity Assessment Scale (MAAS) scores above 4 in a 24-h period and sedative and/or narcotic doses above the established sedation and analgesia protocol or a combination of two or more sedatives.

Results  

Twenty-three (16.1%) of 143 enrolled patients exhibited severe agitation. Agitated patients were younger (hazard ratio [HR] 1.32), more likely to be admitted from an outside hospital ICU (HR 2.48), had lower pH (HR 1.55) and PaO₂/FIO₂ less than 200 mmHg (HR 2.59). Agitated patients had longer MICU stays (median 12 versus 5 days, p<0.0001) and more ventilator days (median 14 versus 6, p<0.0001). Agitated patients were more likely to self-extubate (26% versus 6%, p=0.002). Benzodiazepines, narcotics and neuromuscular blocking agents were administered more frequently and at higher doses, but haloperidol was not.

Conclusion  

Severe agitation occurs commonly in critically ill patients and is associated with adverse events including longer ICU stays, duration of mechanical ventilation and self-extubation.