Implications of hospital evacuation after the Northridge, California, earthquake

On January 17, 1994, an earthquake with a moment magnitude (total energy release) of 6.7 occurred in Northridge, California, leading to the evacuation of patients from several hospitals. We examined the reasons for and methods of evacuation and the emergency-management strategies used. The experience in California may have implications for hospital strategies for responding to any major disaster, including an act of terrorism.

From September 1995 to September 1996, we surveyed all acute care hospitals in Los Angeles County that reported having evacuated patients after the Northridge earthquake. Physicians, nurses, hospital administrators, and staff on duty at the hospitals during the evacuation responded to a 58-item structured questionnaire.

Eight of 91 acute care hospitals (9 percent) were evacuated. Six hospitals evacuated patients within 24 hours (the immediate-evacuation group), four completely and two partially. All six cited nonstructural damage such as water damage and loss of electrical power as a major reason for evacuation. Five hospitals evacuated the most seriously ill patients first, and one hospital evacuated the healthiest patients first. All hospitals used available equipment to transport patients (blankets, backboards, and gurneys) rather than specialized devices. No deaths resulted from evacuation. One hospital evacuated patients after 3 days and another after 14 days because of structural damage, even though initial inspections had shown no damage (the delayed-evacuation group). Both hospitals required demolition. Some hospitals identified destinations for their evacuated patients independently, whereas others sought the assistance of the Los Angeles County Emergency Operations Center; the two strategies were equally effective.

After even a moderate earthquake, hospitals are at risk for both immediate nonstructural damage that may force them to evacuate patients and the delayed discovery of structural damage resulting in permanent closure. Evacuation of large numbers of inpatients from multiple hospitals can be accomplished quickly and safely with the use of available resources and personnel.