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Some patients on mechanical ventilation fare worse at low-volume hospitals

It has been suggested that adult critical care services be regionalized at high-volume hospitals, similar to trauma and neonatal intensive care. A new Canadian study of critical care patients on mechanical ventilation suggests that ventilated surgical intensive care unit (ICU) patients do not necessarily fare better at high-volume hospitals. However, mechanically ventilated medical ICU patients at low-volume hospitals, which do not routinely transfer them to higher volume hospitals, may benefit from regionalization of critical care services. These differences may be due to variation in critical care practice in Ontario or other factors. For example, Ontario hospitals commonly have a single mixed medical-surgical ICU, while specialty-focused ICUs for trauma or cardiac surgery are uncommon.

Nevertheless, larger studies are needed to determine whether this finding is significant, caution the researchers. They examined the relationship between hospital volume of ventilated patients and the chances of dying within 30 days of initiation of mechanical ventilation among 13,846 medical and 6,373 surgical patients receiving mechanical ventilation for more than 2 days between 1998 and 2000 in Ontario, Canada.

There was no effect of volume on mortality for surgical patients. Among medical patients, those treated at the lowest-volume hospitals (less than 100 ventilation episodes per year) had a nonsignificant increase in mortality compared with patients treated at the highest-volume hospitals (700 or more episodes per year). Within the lowest-volume hospitals, the proportion of patients transferred to larger hospitals was 81 percent for hospitals with less than 20 episodes treated per year and only 32 percent for hospitals with 20 to 99 episodes treated per year. The study was supported in part by the Agency for Healthcare Research and Quality (HS11902).

See "Hospital volume and mortality for mechanical ventilation of medical and surgical patients: A population-based analysis using administrative data," by Dale M. Needham, M.D., Ph.D., Susan E. Bronskill, Ph.D., Deanna M. Rothwell, M.Sc., and others, in the September 2006 Critical Care Medicine 34(9), pp. 2349-2354.

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