| Background |
Gold standard for diagnosis of pneumothorax in people is computed tomography (CT). Initial reports suggest high sensitivity of ultrasound (US) for detection of pneumothorax. |
| Rational and Objective |
The hypothesis was US would be more sensitive than supine (ventrodorsal) chest x-ray for detection of pneumothorax |
| Trial Design |
Retrospective study |
| Patient population and location |
Level 1 trauma center 2018-2020 |
| Methods |
- Chest x-ray and US done prior to intervention or CT
- Trained registered sonographer
- Real time evaluation and immediate evaluation by radiologist
- Immediate tube thoracostomy defined as need for chest tube within 8 hours of admission
|
| Endpoints (if applicable) |
n/a |
| Results |
- 568 patients diagnosed with pneumothorax, 363 met study criteria
- 191 occult – small air pockets/blebs on CT – excluded from subsequent analysis
- 87% blunt trauma, 13% penetrating trauma
- Sensitivity of x-ray 43%, sensitivity of US 35% in 363 patients
- Removal of occult pneumothorax:
- x-ray sensitivity 78% – false negative 22%
- US sensitivity 65% – false negative 36%
- 50% false negative needed chest tube, 85% immediately
- First study with findings suggesting x-ray better than US
- Many tubes placed after repeat chest x-ray (at 1 to 6 hours)
|
| Limitations |
- Single centre, retrospective study
- Selection bias possible
- False positives not included as not identified in this study
- Follow-up examinations not done so pneumothorax may have developed in some patients that were not identified in the medical record
|
| Clinical Relevance Conclusions |
- Caution when using US to positively diagnose significant pneumothorax
- Maintain high level of suspicion; repeat exams and imaging are important
- More studies needed in veterinary medicine to determine if similar findings especially as lateral view used more commonly than ventrodorsal
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