Chest X-ray and the NEXUS Chest Decision Rule
The NEXUS Chest decision instrument has been validated to identify which patients require chest imaging following blunt trauma in patients over the age of 14. The rule states that a patient:
- with no chest pain or tenderness
- with no distracting injury or intoxication
- who is younger than 60 years of age
- whose mechanism did not involve rapid deceleration
does not need a routine chest x-ray.5
This has been validated by the author of the rule in a multicentre study at nine level 1 Trauma centres in the US which enrolled 9905 patients. Thoracic injury seen on chest imaging was seen in 1478 (14.9%) patients, with 363 (24.6%) of these having major clinical significance. 1079 (73.0%) had minor clinical significance, and 36 (2.4%) had no clinical significance.
The NEXUS Chest rule had a sensitivity of 98.8% (95% CI, 98.1%99.3%), a negative predictive value of 98.5% (95% CI, 97.6%.699.1%), and a specificity of 13.3% (95% CI, 12.6%14.1%) for thoracic injury. The sensitivity and negative predictive value for thoracic injury with clinically major injury were 99.7% (95% CI, 98.2%100.0%) and 99.9% (95% CI, 99.4%100.0%), respectively. There has been no external validation study in the UK.6