Unplanned transfers to a medical intensive care unit: causes and relationship to preventable errors in care.

BACKGROUND: Unplanned intensive care unit (ICU) transfers may result from errors in care but the frequency of their occurrence, and whether these transfers might be prevented, has not been investigated.
OBJECTIVE: To determine why unplanned transfers occur, what fraction results from errors in care, whether they are preceded by changes in clinical status and if so, whether earlier or different responses might prevent the transfers.
DESIGN: Retrospective study.
SETTING: University-affiliated hospital. PATIENTS: All patients 18 to 89 years with unplanned transfers to the medical ICU from June 1, 2005 to May 30, 2006. INTERVENTION: None. MEASUREMENTS: Demographics, admission and transfer diagnoses, clinical triggers preceding the transfer, mortality, judgment by three reviewers about cause of transfer and whether it could have been prevented.
RESULTS: A total of 152 patients had unplanned transfers. The most common reasons were worsening of the problem for which the patient was admitted (48%) and development of a new problem (39%). Errors in care accounted for 29 transfers (19%), 15 of which were due to incorrect triage at the time of admission, and 14 due to iatrogenic errors. Of the 14 iatrogenic errors, the investigators determined that eight transfers might have been prevented by an earlier intervention. Agreement among the three reviewers was moderate to almost perfect (κ 0.55-0.90).
CONCLUSIONS: Although 19% of unplanned transfers to medical ICUs are associated with errors in care, almost 80% of these seem to be preventable. Most of the preventable errors resulted from inappropriate admission triage.