The confusion assessment method--a tool for delirium detection by the acute pain service

Delirium is an acute fluctuating disturbance in cognitive status, linked to increased morbidity and mortality. The purpose of this pilot study was to assess the feasibility in terms of required time and yield of delirium monitoring by the Acute Pain Service (APS) using the Confusion Assessment Method for Intensive Care Unit instrument.

Patients undergoing surgery requiring more than 2 days of hospital stay were recruited. Each patient was assessed daily for 2 days after surgery using the Confusion Assessment Method for Intensive Care Unit. Patients were also assessed for orientation to person, place, and time. Any notes of confusion or delirium made by physicians or nursing staff were gathered.

145 patients were recruited. Each patient encounter required an average 2.3 +/- 0.3 minutes for the assessment (95% CI). The incidence of delirium within 2 days after surgery was 7.6%. Only 18% of the patients diagnosed with delirium by the APS were noted as being confused by the medical or nursing staff.

The use of this tool required little training, and only 2 minutes per patient. It detected more patients with delirium than did the standard nursing assessments or other patient-clinician interactions. The use of this instrument by the pain service was feasible in terms of time consumption and most likely would be valuable in its yield. Early detection may help in initiating prompt treatment, eliminating known risk factors and thus reducing morbidity.