Diaphragmatic injuries are graded I-V with increasing severity having higher grading.

• Grade I = Contusion
• Grade II = Laceration <=2 cm
• Grade III = Laceration 2-10 cm
• Grade IV = Laceration >10 cm with tissue loss <=25 cm²
• Grade V = Laceration with tissue loss >25 cm2

Note that the grading is increased by one grade for bilateral injuries, up to grade III.

References:

Moore EE, Malangoni MA, Cogbill TH, et al. Organ injury scaling. IV: Thoracic vascular, lung, cardiac, and diaphragm. J Trauma. 1994;36(3):299-300.

Trauma.org. Organ Injury Scaling: Diaphragm. http://www.trauma.org/archive/scores/ois-phrenic.html. Last accessed June 13, 2013.