Is ultrasound or chest x-ray best for the diagnosis of pneumothorax in the emergency department?
Date First Published:
November 11, 2008
Last Updated:
June 1, 2009
Report by:
Walid Alsalim, Consultant Emergency Medicine (The Ipswich Hospital NHS Trust)
Search checked by:
David Lewis, The Ipswich Hospital NHS Trust
Three-Part Question:
In [patients with suspected pneumothorax] is [transthoracic ultrasound or chest x-ray] better at [detecting the pneumothorax].
Clinical Scenario:
A 26-year-old man presents to the ED with a history of blunt trauma to the left trunk. Clinical signs are inconclusive and a supine chest x ray (CXR) demonstrates no pneumothorax. A subsequent CT scan demonstrates a left anterior pneumothorax. You have heard that focused thoracic ultrasound can detect pneumothorax and wonder whether this imaging modality is superior to plain x ray and whether there is any evidence to support this.
Search Strategy:
Medline search via NELH from 1950 until November 2008.
Search Details:
[(exp PNEUMOTHORAX/) OR (exp PNEUMOTHORAX, ARTIFICIAL/) ] AND [exp RADIOGRAPHY, THORACIC/] AND [(exp ULTRASONOGRAPHY/) OR (ultrasound.ti,ab) OR (sonography.ti,ab)]
Outcome:
29 papers were found of which 6 papers were relevant
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Accuracy of Thoracic Sonography in Detection of Pneumothorax After Sonographically Guided Comparison with Chest Radioigraphy. Sartori S, Tombesi P, Trevisani L et al. 2007 Italy | 285 patients post lung biopsy of whom 8 developed pneumothorax | Prospective diagnostic study -single blind |
USS vs CXR, if disagree CT requested. | Sensitivity 100% vs 87.5% CXR. Specifity 100% vs 100% CXR. | -Low prevalence of pneumothorax in study population (2.8%) -No gold standard in study group (only one CT) |
| Value of high resolution ultrasound in detecting a Pneumothorax. Chung MJ, Goo MJ, Im JG, Cho MJ, Kim JS. 2005 South Korea | 97 post needle aspiration and lung biopsy: of whom 35 developed Pneumothorax | Prospective diagnostic study -single blind |
USS vs CXR, CT as gold standard | Sensitivity 80% vs 47% CXR. Specificity 94% vs 94% CXR. | -Small study -Single sonographer |
| A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax. Blaivas M, Lyon M, Duggal S. 2005 USA | 176 non-consecutive blunt trauma patients | Prospective diagnostic study -single blind |
Pneumothorax on CT or rush of air on insertion of chest drain USS vs CXR | Sensitivity 98.1% (89.9-99.9) USS vs 75.5% (61.7-86.2) CXR. Specificity 99.2%(95.6-99.9) USS vs 100% (97.1-100) CXR. | #NAME? |
| Hand-held Sonography for detecting post-traumatic pneumothoraces: The extended focussed assessment with sonography for trauma (FAST). Kirkpatrick AW, Sirois M, Laupland KB et al. 2004 Canada | 225 post-trauma patients | Prospective diagnostic study | Pneumothorax on USS v CXR, CT part of composite standard | Sensitivity 48.8% (33.3-64.5) USS vs 20.9% CXR. Specificity 98.7% (96.1-99.7) USS vs 99.6% (97.5-100) CXR. | #NAME? |
| Surgeon-performed ultrasound for pneumothorax in the trauma suite. Knudtson JL, Dort JM, Helmer SD, & Smith RS. 2004 USA | 328 consecutive trauma patients | Prospective diagnostic study | USS v CXR | Sensitivity 92.3% (74.4-97.9) USS. Specificity 99.7% (98.9-99.9) USS. | -Not clearly blinded -CXR used as gold standard. |
| Prospective evaluation of thoracic ultrasound in the detection of pneumothorax Dulchavsky SA, Schwarz KL, Kirkpatrick AW et al. 2001 USA | 382 stable surgical patients (95% post-traumatic) | prospective diagnostic study | USS v CXR | Sensitivity 95%(89-95) Specificity 100% (99-100) | -Only stable patients were recruited -CXR used as gold standard |
Author Commentary:
These studies were relatively small and only two were obviously blinded. The sensitivity of transthoracic ultrasound for the diagnosis of pneumothorax varied between 58.9% and 100% and specificity varied between 94% and 100%. The CT gold standard was used in four studies. In such cases CT may be able to find small pneumothoraces not visible on CXR. The clinical relevance of such small pneumothoraces in the resuscitation room is debatable (unless intermittent positive pressure ventilator is being considered). There is agreement on diagnostic ultrasonographic signs used to confirm pneumothorax. These papers suggest that transthoracic ultrasound is a superior modality for the diagnosis of pneumothorax, especially when the patient must remain supine. All ultrasound examinations are known to be operator dependent. These studies do address the training requirements for clinicians wanting to perform this investigation.
Bottom Line:
ED transthoracic ultrasound is better than plain
x ray in the diagnosis of pneumothorax in the
supine patient. CT thorax is the gold standard
for diagnosis.
x ray in the diagnosis of pneumothorax in the
supine patient. CT thorax is the gold standard
for diagnosis.
Level of Evidence:
Level 2: Studies considered were neither 1 or 3
References:
- Sartori S, Tombesi P, Trevisani L et al.. Accuracy of Thoracic Sonography in Detection of Pneumothorax After Sonographically Guided Comparison with Chest Radioigraphy.
- Chung MJ, Goo MJ, Im JG, Cho MJ, Kim JS.. Value of high resolution ultrasound in detecting a Pneumothorax.
- Blaivas M, Lyon M, Duggal S.. A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax.
- Kirkpatrick AW, Sirois M, Laupland KB et al. . Hand-held Sonography for detecting post-traumatic pneumothoraces: The extended focussed assessment with sonography for trauma (FAST).
- Knudtson JL, Dort JM, Helmer SD, & Smith RS.. Surgeon-performed ultrasound for pneumothorax in the trauma suite.
- Dulchavsky SA, Schwarz KL, Kirkpatrick AW et al.. Prospective evaluation of thoracic ultrasound in the detection of pneumothorax