Thoracic Trauma Severity Score

Patient selection: blunt thoracic trauma (full inclusion criteria on page 498)

Parameters:

(1) age of the patient in years

(2) PaO2 to FIO2 ratio

(3) pulmonary contusion

(4) pleural involvement

(5) rib fractures

Point assignment corresponds to the Grade of the injury. The grades ranged from 0 (normal function) to 4 (most severe). Since the impact of Grade 4 injuries were higher, the grade and points were raised to V and 5 respectively (second column, page 498).

where:

• The ranges for PaO2 to FIO2 ratio overlap at 200 and 300. I adjusted the ranges to avoid overlap.

• "< 2 lobes bilateral" is a bit ambiguous. The only option that I can think of to satisfy this is the presence of bilateral disease with 1 lobe on one side and 2 lobes on the other.

• A rib with multiple fractures would be counted as 1 fractured rib. I do not see handling for a unilateral fracture of >= 7 ribs. "> 3 bilateral" could alternatively be interpreted as > 3 ribs fractured on each side.

• The handling of a bilateral pneumothorax is a guess.

• Thoracotomy is an additional risk factor that is associated with increased mortality.

total score =

= SUM(points for all 5 parameters)

Interpretation:

• minimum score: 0

• maximum score: 5

• The higher the score the more severe the thoracic blunt trauma.

• I was unable to find what cutoff value the authors used.

Performance:

• The area under the ROC curve is reported as 0.92, but I am unable to determine what cutoff value was used or what was being measured, although it appears to be prediction of respiratory complications (Figure 3).