Chest Trauma
Pneumothorax - Simple

Introduction

Pneumothorax is the collection of air in the pleural space. Air may come from an injury to the lung tissue, a bronchial tear, or a chest wall injury allowing air to be sucked in from the outside.

Simple pneumothorax

A simple pneumothorax is a non-expanding collection of air around the lung. The lung is collapsed, to a variable extent. Diagnosis on physical examination may be very difficult. The classical signs of reduced air entry and resonance to percussion are often difficult or impossible to appreciate. Careful palpation of the chest wall and apices may reveal subcutaneous emphysema and rib fractures as the only sign of an underlying pneumothorax.

Simple Pneumothorax	Detail	Detail

A chest X-ray is usually diagnostic, but may miss small pneumothoraces, especially with the patient supine. The presence of rib fractures on a chest X-ray should prompt a careful search for a pneumothorax. One side of the chest may appear more radiolucent than the other. This may represent an overlying pneumothorax, or alternatively an underlying haemothorax on the opposite side. A deep sulcus sign is indicative of an anterior pneumothorax.

When a haemothorax is visible on the erect chest X-ray, the presence of a flat meniscus laterally indicates the presence of an associated pneumothorax.

Meniscus of haemothorax	Meniscus of haemopneumothorax

CT Scanning is more sensitive for the presence of pneumothorax than plain chest X-ray. However the significance of these small pneumothoraces is unknown. A small anterior pneumothorax is not visible on the plain radiograph but visible on CT in the example below. Many of these 'occult pneumothoraces' may be managed without chest tubes, even in the presence of positive pressure ventilation. More recently, ultrasound has shown promise in the diagnosis of pneumothoraces, although evaluation is difficult and operator dependent.

Chest X-ray Normal	CT with anterior left pneumothorax

Management

Most simple pneumothoraces will require placement of an intercostal chest drain as definitive treatment. Small pneumothoraces, especially those visible only on CT, may be watched expectantly. The decision to observe is based on the patient's clinical status and subsequent planned procedures. Chest tube placement may be appropriate in these cases if there are multiple injuries, if a patient is due to undergo prolonged anaesthesia, or if a patient is due to be transferred a significant distance - where detection of an increasing or tension pneumothorax may be difficult or delayed.
 

CHEST TRAUMA INITIAL EVALUATION PNEUMOTHORAX TENSION PNEUMO OPEN PNEUMO HAEMOTHORAX CONTUSION RIB FRACTURE / FLAIL AORTIC INJURY CHEST DRAINS

Classic signs of
simple pneumothorax

Trachea
Expansion
Percussion Note
Breath sounds

PNEUMOTHORAX (SIMPLE) PRIMARY SURVEY AIRWAY BREATHING CIRCULATION DISABILITY EXPOSURE ADJUNCTS CXR SECONDARY SURVEY

Subcutaneous Emphysema
Pneumothorax

Supine left pneumothorax or right haemothorax?

Deep sulcus sign

References

CXR vs CT

Omert L, Yeaney WW, Efficacy of thoracic computerized tomography in blunt chest trauma. Protetch J. Am Surg. 2001 Jul;67(7):660-4.

Neff MA, Monk JS Jr, Peters K, Nikhilesh A. Detection of occult pneumothoraces on abdominal computed tomographic scans in trauma patients. J Trauma. 2000 Aug;49(2):281-5.

Guerrero-Lopez F, Vazquez-Mata G, Alcazar-Romero PP, et al. Evaluation of the utility of computed tomography in the initial assessment of the critical care patient with chest trauma. Crit Care Med. 2000 May;28(5):1370-5.

Hill SL, Edmisten T, Holtzman G, Wright A. The occult pneumothorax: an increasing diagnostic entity in trauma. Am Surg. 1999 Mar;65(3):254-8.

Trupka A, Waydhas C, Hallfeldt KK, Nast-Kolb D, Pfeifer KJ, Schweiberer L. Value of thoracic computed tomography in the first assessment of severely injured patients with blunt chest trauma: results of a prospective study. J Trauma. 1997 Sep;43(3):405-11; discussion 411-2.

Conservative Rx of Occult Pneumothorax

Holmes JF, Brant WE, Bogren HG, London KL, Kuppermann N. Prevalence and importance of pneumothoraces visualized on abdominal computed tomographic scan in children with blunt trauma. J Trauma. 2001 Mar;50(3):516-20.

Brasel KJ, Stafford RE, Weigelt JA, Tenquist JE, Borgstrom DC. Treatment of occult pneumothoraces from blunt trauma. J Trauma. 1999 Jun;46(6):987-90; discussion 990-1.

Wolfman NT, Myers WS, Glauser SJ, Meredith JW, Chen MY. Validity of CT classification on management of occult pneumothorax: a prospective study. AJR Am J Roentgenol. 1998 Nov;171(5):1317-20.

Thoracic US

Rowan KR, Kirkpatrick AW, Liu D, Forkheim KE, Mayo JR, Nicolaou S. Traumatic pneumothorax detection with thoracic US: correlation with chest radiography and CT--initial experience. Radiology. 2002 Oct;225(1):210-4.

Kirkpatrick AW, Ng AK, Dulchavsky SA, et al. Sonographic diagnosis of a pneumothorax inapparent on plain radiography: confirmation by computed tomography. J Trauma. 2001 Apr;50(4):750-2.