An Assessment of Casualties Undergoing Delayed Surgical Intervention in the Combat Setting

The US military is transitioning into a posture preparing for large-scale combat operations in which delays in evacuation may become common. It remains unclear which casualty population can have their initial surgical interventions delayed, thus reducing the evacuation demands.

We performed a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on casualties who received prehospital care. In this, we sought to determine (1) of those who underwent operative intervention, the proportion of surgeries occurring ≥3 days post-injury, and (2) of those who underwent early versus delayed surgery, the proportions who required blood products.

There were 6,558 US military casualties who underwent surgical intervention-6,224 early (less than 3 days from injury) and 333 delayed (≥ 3 days from injury). The median Injury Severity Score (ISS) was higher in the early cohort (10 versus 6, p is less than 0.001). Serious injuries to the head were more common in the early cohort (12% versus 5%, p is less than 0.001), as were the thorax (13% versus 9%, p=0.041), abdomen (10% versus 5%, p=0.001), extremities (37% versus 14%, p is less than 0.001), and skin (4% versus less than 1%, p=0.001). Survival to discharge was lower in the early cohort (97% versus 100%, p is less than 0.001). Mean whole blood consumption was higher in the early cohort (0.5 versus 0 units, p is less than 0.001), as was packed red blood cells (6.3 versus 0.5, p is less than 0.001), platelets (0.9 versus 0, p is less than 0.001), and fresh frozen plasma (4.5 versus 0.2, p is less than 0.001). The administration of any units of packed red blood cells and whole blood was higher for the early cohort (37% versus 7%, p is less than 0.001), as was a ≥3 units threshold (30% versus 3%, p is less than 0.001), and ≥10 units threshold (18% versus 1%, p is less than 0.001).

Few combat casualties underwent delayed surgical interventions defined as ≥3 days post injury, and only a small number of casualties with delayed surgical intervention received blood products. Casualties who received early surgical intervention were more likely to have higher injury severity scores, and more likely to receive blood.