Inappropriate distribution of casualties in mass casualty incidents (MCIs) may result in patient overload in primary medical facilities.

The aim of this study was to review the consequences of evacuating casualties from a bus accident to a single rural hospital and lessons learned regarding policy of casualty evacuation.

Hospital medical records of all casualties from primary and tertiary hospitals were independently reviewed by two senior trauma surgeons. In addition four senior trauma surgeons reviewed the impact of treatment provided in the primary hospital on patient outcomes.

31 survivors from the accident were transferred to the closest local hospital; 4 died en route to the hospital or within 30 minutes of arrival. 27 casualties were air evacuated from the local hospital within 2.5 to 6.15 hours to level I and II hospitals. Under-triage of 15% and over-triage of 7% were noted. 4 casualties did not receive treatment at the local hospital that might have improved their condition.

Over and under-triage might have been due to minimal trauma related experience of primary hospital personnel. Evacuation of casualties from an MCI to a limited capacity hospital may overwhelm the facility and affect its ability to provide appropriate medical care.

In MCIs occurring in rural areas, only immediate unstable casualties should be transferred to the closest primary hospital. On-site Advanced Life Support (ALS) should be administered to non-severe casualties until they can be evacuated directly to tertiary care hospitals. First responders must be trained to provide ALS to non-severe casualties until evacuation resources are available.