One of the five 2014 American College of Surgeons’ Choosing Wisely recommendations is to avoid routing whole-body CT imaging of trauma patents, also known as the ‘pan-CT’. Until now, no validated decision instrument existed to help guide clinicians decide whether to obtain a chest CT in the setting of blunt trauma. This month, Dr. Robert Rodriguez and the multi-institutional NEXUS Chest CT research team published a paper describing the derivation and validation of 2 decision instruments in PLOS Medicine .
Prospective multicenter observational study at 8 urban level-1 trauma centers enrolling all patients who sustained blunt trauma and underwent a chest xray (CXR) and/or chest CT. Injury outcome measures were divided into clinically “major” and “minor” injuries.
Using 14 clinical criteria, the “Chest CT-Major” and “Chest CT-All” decision instruments were developed to screen for (major only) vs (major + minor) injuries, respectively, in the hopes of decreasing chest CT utilization.
Two validated decision instruments were described, Chest CT-Major and Chest CT-All, with 6 and 7 criteria, respectively.
|NEXUS Chest Decision Instrument (Chest CT-Major):
To help rule out clinically MAJOR injuries
|1. Abnormal chest x-ray
|2. Distracting injury (same as in NEXUS c-spine definition)
|3. Chest wall tenderness*
|4. Sternal tenderness*|
|5. Thoracic spine tenderness*|
|6. Scapular tenderness*|
* One might combine these 4 criteria into 1 criterion of any thoracic tenderness (imagine a burrito wrap rule).
|NEXUS Chest Decision Instrument (Chest CT-All):
To help rule out clinically MAJOR and MINOR injuries
|All 6 criteria from Chest CT-Major above plus…|
|7. Rapid deceleration
Validation Phase Results
A total of 11,477 patients were enrolled with a median age of 46 y (6,002 derivation phase, 5,475 validation phase).
|• Chest CT-Major||99.2%
|• Chest CT-All||99.2%
|MAJOR and MINOR INJURIES|
|• Chest CT-Major||90.7%
|• Chest CT-All||95.4%
Values listed with 95% confidence intervals in parentheses
LR = Likelihood ratio
What Did the Decision Instruments Miss?
- Major Injuries: Missed 1 of 120 patients (80 year old man who fell 7 stairs and a subarachnoid hemorrhage, who also sustained an isolated pneumothorax requiring a chest tube)
- Minor Injuries: Missed 64 of 691 patients (included rib fractures, sternal fracture, pulmonary contusion, thoracic spine fracture, scapular fracture, pneumothorax, >1 minor injury)
- Major Injuries: Also missed same patient above (1 of 120 patients): 80 year old man who fell 7 stairs and a subarachnoid hemorrhage, who also sustained an isolated pneumothorax requiring a chest tube
- Minor Injuries: Missed 31 of 691 patients (included rib fractures, sternal fracture, pulmonary contusion, thoracic spine fracture, scapular fracture, pneumothorax, >1 minor injury)
The NEXUS Chest CT research team should be applauded for rigorously addressing a common issue of Chest CT utilization for blunt trauma patients in the era of pan-CT’ing. Developing a 2-tier decision instrument, the Chest CT-Major and Chest CT-All, helps institutions address whether they wish to use a more risk-tolerant or risk-averse approach, respectively. More specifically, do they want to detect clinically “major” injuries only or also clinically minor injuries that do not require acute surgical interventions?
This study provides a validated tool to safely supplement clinician judgment in the decision to obtain chest CT imaging for blunt trauma patients.
The decision instruments:
- Chest CT-Major: Abnormal chest -ray + distracting injury + thoracic tenderness
- Chest CT-All: Above + deceleration mechanism
- Both decision instruments have >99% sensitivity to detect clinically major injuries
- The Chest CT-All instrument has a >95% sensitivity to detect major AND minor injuries.
- Appropriate use of these decision tools may safely allow clinicians to forego 25-37% of chest CTs.
- Rodriguez RM, Langdorf MI, Nishijima D, et al. Derivation and Validation of Two Decision Instruments for Selective Chest CT in Blunt Trauma: A Multicenter Prospective Observational Study (NEXUS Chest CT). PLoS Med. 2015; 12(10): e1001883. PMID: 26440607 [Open Access PDF]