NEXUS Chest Decision Instrument for Blunt Chest Trauma

Why Use

This decision instrument can help reduce unnecessary imaging by identifying patients at low risk of thoracic injury, which reduces radiation exposure and provides faster evaluation for emergency providers and their patients, allowing them to focus on treatment, evaluation of other injuries or problems, or education and reassurance.

When to Use

Pregnant patients with minor trauma. Patients who are of indeterminate risk. Young patients, in whom radiation exposure is more risky.

Formula

Pearls / Pitfalls

The NEXUS Chest Decision Instrument can rapidly identify “very low-risk” patients with blunt thoracic trauma who would not benefit from chest imaging. It was developed due to the concern of radiation from Chest CT that is now common in the evaluation of trauma patients, and was developed at 3 Level 1 trauma centers in over 2600 patients. It uses 7 criteria to identify this low-risk cohort who have a <2% chance of having any thoracic injury (and 1% chance of having clinically significant thoracic injuries). It was designed to not miss any injuries, but is not very specific -- just because a patient may not meet low-risk criteria does not mean the patient must be imaged. Points to keep in mind: 1 isolated rib fracture was not included as a “thoracic injury.” Some providers may disagree with the study's definitions of “clinically significant.” Clavicular tenderness is not included as “chest wall tenderness.” Distracting injury is purposefully vaguely defined and is at the discretion of the provider: “any condition thought by the clinician to be producing sufficient pain to distract the patient from a second (intrathoracic) injury.” From the original paper: Long bone fractures. Visceral injuries requiring surgical consultation. Large lacerations, degloving injuries, or crush injuries. Large burns. Any other injury producing acute functional impairment. Physicians may also classify any injury as distracting if it is thought to have the potential to impair the patient’s ability to appreciate other injuries. Intoxication is also similarly intentionally vague: A history of intoxication or recent intoxicating ingestion is provided by a patient or observer. Test of bodily secretions positive for alcohol or drugs. Patient has physical evidence suggesting intoxication (odor of alcohol, slurred speech, ataxia, dysmetria, or other cerebellar findings), or behavior consistent with intoxication and unexplained by medical or psychiatric illness.

Advice

In patients who get chest x-ray and CT is being considered, the NEXUS creators recommend using the NEXUS Chest CT Decision Instrument . Adequate pain control is always important in patients with trauma. Consider initial evaluation with chest x-ray in stable patients with isolated chest trauma. CT will obviously find many more injuries than x-ray, regardless of their true clinical significance. CT may be more useful in patients with multiple injuries or those who are sicker.

More Information

Criteria Point Value Age >60 years +1 Rapid deceleration mechanism (fall >20 ft or MVC >40 mph) +1 Chest pain +1 Intoxication +1 Altered mental status +1 Distracting painful injury +1 Tenderness to chest wall palpation +1 Score interpretation: NEXUS Score is 99% sensitive for clinically significant thoracic injury. If NEXUS ≥1: In well-appearing patient with no evidence of multi-organ injury, consider CXR only without CT. In ill-appearing patients and/or those who will receive workup for other serious injury, consider chest CT as well.