Estimating blood transfusion requirements in preparation for a major earthquake: the Tehran, Iran study

Tehran, Iran, with a population of approximately seven million people, is at a very high risk for a devastating earthquake. This study aims to estimate the number of units of blood required at the time of such an earthquake.

To assume the damage of an earthquake in Tehran, the researchers applied the Centre for Earthquake and Environmental Studies of Tehran/Japan International Cooperation Agency (CEST/JICA) fault-activation scenarios, and accordingly estimated the injury-to-death ratio (IDR), hospital admission rate (HAR), and blood transfusion rate (BTR). The data were based on Iran's major earthquakes during last two decades. The following values were considered for the analysis: (1) IDR = 1, 2, and 3; (2) HAR = 0.25 and 0.35; and (3) BTR = 0.05, 0.07, and 0.10. The American Association of Blood Banks' formula was adapted to calculate total required numbers of Type- O red blood cell (RBC) units. Calculations relied on the following assumptions: (1) no change in Tehran's vulnerability from CEST/JICA study time; (2) no functional damage to Tehran Blood Transfusion Post; and (3) standards of blood safety are secure during the disaster responses. Surge capacity was estimated based on the Bam earthquake experience. The maximum, optimum, and minimum blood deficits were calculated accordingly.

No deficit was estimated in case of the Mosha fault activation and the optimum scenario of North Tehran fault. The maximum blood deficit was estimated from the activation of the Ray fault, requiring up to 107,293 and 95,127 units for the 0-24 hour and the 24-72 hour periods after the earthquake, respectively. The optimum deficit was estimated up to 46,824 and 16,528 units for 0-24 hour and 24-72 hour period after the earthquake, respectively.

In most Tehran earthquake scenarios, a shortage of blood was estimated to surge the capacity of all blood transfusion posts around the country within first three days, as it might ask for a 2-8 times more than what the system had produced following the Bam earthquake.