To determine LA50 in Shahid Motahari burn hospital, Tehran, Iran

Lethal area 50 (LA50) index reflects quality of resuscitation process and medical care better than mortality rate of burn injuries. The present study is to evaluate annual LA50 for evaluation and further modification of burns medical care. Medical records of 1326 hospitalized patients who immediately referred to Shahid Motahari burn hospital following burning during October 2004 to September 2005 were included. Data including gender, age, types of burn, percentage of burn and patients’ survival were recorded for all subjects. Frequency of age, gender, types of burn percentage of burn and patients’ survival, and mean age, gender distribution of burns were measured and LA50 (percentage of burned body surface lethal to 50% of patients) was calculated with Regression test. Patient's mean age and mortality rate were 27.6 (±18) years and 28.8% respectively. Thermal burn was the most common type of burning. After significant correlation mortality rate with percentage of burnt surface area (Pearson test, P<0.05, R square=0.756), we determined annual LA50 was 52.38%. Thermal burn is the most lethal cause with LA50 equal to 52.77. Moreover, LA50 is a little lower in female than male patients. LA50 and burned patient's survival have improved in Iran, but are still much lower than those in developed countries, probably due to lack of skilled staff and facilities, exposure to infections and more complicated patients.