The following information has been collected from trauma.org and rearranged to be relevant for the PreHospital Setting.

Chest Injuries

Chest Trauma

Initial Evaluation

Introduction

Hypoxia and hypoventilation are the primary killers of acute trauma patients. Assessment of ventilation is therefore given high priority in the primary survey - as the second 'B' or Breathing stage. It may be obvious that there is a ventilatory problem during assessment of the airway. Similarly, the identification or actual severity of certain conditions may only be determined subsequently, after assessment of the circulation or the use of monitoring or diagnostic adjuncts.

Life-threatening injuries should be identified and treated immediately. Injuries may develop over time, and become life threatening during the course of a resuscitation. Re-assessment and evaluation is therefore extremely important, especially if the patient's condition deteriorates.

Mechanism of Injury

Mechanism of injury is important in so far as blunt and penetrating injuries have different pathophysiologies and clinical courses. Most blunt injuries are managed non-operatively or with simple interventions like intubation and ventilation and chest tube insertion. Diagnosis of blunt injuries may be more difficult and require additional investigations such as CT scanning. In contrast, penetrating injuries are more likely to require operation, and complex investigations are required infrequently. Patients with penetrating trauma may deteriorate rapidly, and recover much faster than patients with blunt injury.

CHEST TRAUMA

INITIAL EVALUATION

PNEUMOTHORAX

TENSION PNEUMO

OPEN PNEUMO

HAEMOTHORAX

CONTUSION

RIB FRACTURE / FLAIL

AORTIC INJURY

CHEST DRAINS

Primary Survey

The principal aim of the primary survey is to identify and treat immediately life-threatening conditions. The life-threatening chest injuries are:

1. Tension Pneumothorax

2. Massive Haemothorax

3. Open Pneumothorax

4. Cardiac Tamponade

5. Flail chest

Secondary Survey

The secondary survey is a more detailed and complete examination, aimed at identifying all injuries and planning further investigation and treatment. Chest injuries identified on secondary survey and its adjuncts are:

1. Rib Fractures & flail chest

2. Pulmonary contusion

3. Simple pneumothorax

4. Simple haemothorax

5. Blunt aortic injury

6. Blunt myocardial injury

Physical examination

Physical examination is the primary tool for diagnosis of acute thoracic trauma. However, in the noisy emergency room, or in the prehospital arena, an adequate physical examination may be very difficult. Even under ideal conditions, signs of significant thoracic injury may be subtle or even absent. It is important also to understand that these conditions develop over time. With the advantages of rapid prehospital transport many of these conditions will not have fully developed by the time the patient reaches the emergency department. While the initial primary survey may identify some of these conditions, an initial normal examination does not exclude any of them, and serial examinations and use of diagnostic adjuncts is important.

Physical examination includes:

Look

Determine the respiratory rate and depth

Look for chest wall asymmetry. Paradoxical chest wall motion

Look for bruising, seat belt or steering wheel marks, penetrating wounds

Feel

Feel for the trachea for deviation

Assess whether there is adequate and equal chest wall movement

Feel for chest wall tenderness or rib 'crunching' indicating rib fractures

Feel for subcutaneous emphysema

Listen

Listen for normal, equal breath sounds on both sides.

Listen especially in the apices and axillae and at the back of the chest (or as far as you can get while supine).

Percuss

Percuss both sides of the chest looking for dullness or resonance (more difficult to appreciate in the trauma room).

Classical physical examination findings:

The size of the injury, and position of the patient will affect the clinical findings. For example, a small haemothorax may have no clinical signs at all. A moderate haemothorax will be dull to percussion with absent breath sounds at the bases in the erect patient, whereas signs will be posterior in the supine patient. This is also reflected in chest X-ray findings.

Note also how a collapsed lung on one side can mimic a tension pneumothorax on the other side. This is a common error, usually occurring when a tracheal tube has been incorrectly placed in the right main bronchus, obstructing the right upper lobe bronchus. This leads to collapse of the right upper lobe and shift of the trachea to the right. The left chest appears hype-resonant compared to the left, and breath sounds may be difficult to determine. The patient may end up with an unnecessary chest drain.

Rib fractures & Flail Chest

Chest wall injury is a extremely common following blunt trauma. It varies in severity from minor bruising or an isolated rib fracture to severe crush injuries of both hemithoraces leading to respiratory compromise.

While many chest injuries will require no specific therapy, they may be indicators of more significant underlying trauma. Multiple rib fractures will often be associated with an underlying pulmonary contusion, which may not be immediately apparent on an initial chest X-ray. Fractures of the lower ribs may be associated with diaphragmatic tears and spleen or liver injuries. Injuries to upper ribs are less commonly associated with injuries to adjacent great vessels. This is especially true of a first rib fracture, which requires a significant amount of force to break and indicates a major energy transfer. A fracture of the first rib should prompt a careful search for other injuries. Note also that the rib cage and sternum provide a significant amount of stability to the thoracic spine. Severe disruption of this 'fourth column' may convert what would otherwise be a stable thoracic spine fracture into an unstable one.

Flail Chest

A flail chest occurs when a segment of the thoracic cage is separated from the rest of the chest wall. This is usually defined as at least two fractures per rib (producing a free segment), in at least two ribs. A segment of the chest wall that is flail is unable to contribute to lung expansion. Large flail segments will involve a much greater proportion of the chest wall and may extend bilaterally or involve the sternum. In these cases the disruption of normal pulmonary mechanics may be large enough to require mechanical ventilation.

The main significance of a flail chest however is that it indicates the presence of an underlying pulmonary contusion. In most cases it is the severity and extent of the lung injury that determines the clinical course and requirement for mechanical ventilation. Thus the management of flail chest consists of standard management of the rib fractures and of the pulmonary contusions underneath.

Diagnosis

Most significant chest wall injuries will be identified by physical examination. Bruising, grazes or seat-belt signs are visible on inspection, and palpation may reveal the crepitis associated with broken ribs. Awake patients will complain of pain on palpation of the chest wall or on inspiration.

A flail chest is identified as paradoxical movement of a segment of the chest wall - i.e. in drawing on inspiration and moving outwards on expiration. This is often better appreciated by palpation than by inspection.

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.

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.

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.

Rib fractures

Ziegler DW, Agarwal NN. 'The morbidity & mortality of rib fractures.' J Trauma 1994;37:975

Dubinsky I, Low A. 'Non-life-threatening blunt chest trauma: appropriate investigation and treatment.' Am J Emerg Med 1997;15:240

Lee RB, Bass SM, Morris JA jr et al. 'Three or more rib fractures as an indicator for transfer to a level 1 trauma center: a population-based study.' J Trauma 1990;30:689

Flail Chest

Clark GC, Schecter WP, Trunkey DD. 'Variables affecting outcome in blunt chest trauma: Flail chest vs. pulmonary contusion.' J trauma 1990;30:93

Freedland M, Wilson RF, Bender JS. 'The management of flail chest injury: Factors affecting outcome.' J Trauma 1990;30:1460

Pelosi P, Cereda M, Foti G. 'Alterations of lung and chest wall mechanics in patients with acute lung injury: effects of positive end-expiratory pressure.' Am J Resp Crit Care Med 1995;152:531

Craven KD, Oppenheimer L, Wood LD. 'Effects of contusion and flail chest on pulmonary perfusion and oxygen exchange.' J Appl Physiol 1979;47:729

Landercasper J, Cogbill T, Lindesmith L. 'Long-term disability after flail chest injury.' J Trauma 1984;24:410