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Home > Articles > 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. Diangosis 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.

Primary Survey

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

Monitoring Adjuncts

    1. Oxygen Saturation
    2. End-tidal CO2 (if intubated)



Diagnostic Adjuncts



Interventions

  • Chest drain

  • ED Thoracotomy



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:



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.

 
Trachea
Expansion
Breath Sounds
Percussion
Tension Pneumothorax
Away
Decreased.
Chest may be fixed in hyper-expansion
Diminshed or absent
Hyper-resonant
Simple Pneumothorax
Midline
Decreased
May be diminished
May be hyper-resonant. Usually normal
Haemothorax
Midline
Decreased
Diminished if large. Normal if small
Dull, especially posteriorly
Pulmonary Contusion
Midline
Normal
Normal. May have crackles
Normal
Lung collapse
Towards
Decreased
May be reduced
Normal

Note also how a collapsed lung on one side can mimic a tension pneumothorax on the other side. This is a common error, usually occuring 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.

Right upper lobe collapse
Unnecessary left chest drain

Monitoring adjuncts

Oxygen saturation

Pulse oximetry allows continuous, non-invasive assessent of arterial haemoglobin oxygen saturation. Continuous oxgen saturation monitoring should be used during the resuscitation of all trauma patients.

End-tidal carbon dioxide

End-tidal carbon dioxide monitoring (ETCO2) should be used in all intubated trauma patients. ETCO2 is the only definitive method of confirming placement of a tracheal tube. Other methods, such as watching for chest wall movement and listening to breath sounds or for air in the stomach are inaccurrate, especially in the setting of the trauma resuscitation room.

ETCO2 also allows for the estimation of the arterial PaCO2 level, and for its continuous montioring. This is important for all mechanically ventilated patients and vital for patients with traumatic brain injury.

Diagnostic adjuncts

Chest X-ray

The plain antero-posterior chest radiograph remains the standard initial evaluation for the evaluation of chest trauma. The indications and techniques are slightly different for blunt and penetrating trauma:

Blunt

All blunt trauma patients should have a portable chest X-ray performed in the trauma resuscitation room. The discussion on physical examination above highlights the inaccurracy of clinical signs in the trauma patient. The chest X-ray is a rapid screening examination that will identify significant thoracic problems requiring intervention.

Blunt (supine)
right Haemothorax

Chest radiographs in blunt trauma patients are taken in the supine position, as unstable spinal fractures have not been ruled out at this stage. Chest films should be slightly over-penetrated to allow better visualisation of the thoracic spine, paraspinal lines and aortic outline.

Penetrating

Patients with a stab wound that may have violated the thoracic cavity or mediastinum should have a chest X-ray. In practice, this means all patients with stab wounds between the neck and the umbilicus (front or back!).

Penetrating (erect)
left haemothorax

For gunshot wounds, all patients with wounds between the neck and the pelvis/buttock area should have a chest film. This is especially true if the bullet track is unclear, there is a missing bullet or an odd number of entry/exit wounds. The chest-X-ray in penetrating trauma should be traken with the patient sitting upright if possible. This will increase the sensitivity for detecting a small haemothorax, pneumothorax or diaphragm injury.

FAST examination

Focused Abdominal Sonography for Trauma (FAST) is a rapid ultrasound examination performed in the trauma resuscitation room looking specifically from blood - in the peritoneum, pericardium or hemithorax.

FAST: Haemothorax,
diaphragm & liver

Currently, FAST is indicated for all haemodynamically unstable blunt trauma patients. It may also have a role in some patients with penetrating trauma.

Arterial Blood Gas analysis


Arterial blood gas analyses should be drawn on all intubated and ventilated trauma patients, and any patient with significant chest trauma or eveidence of haemodynamic instability.

Computed Tomography

Secondary Survey

As part of the secondary survey the chest is fully examined, front and back. Special attention is paid to identifying any missed injuries or progression of previously identified injuries. The examination is also directed by findings on the chest X-ray or by information from monitoring adjuncts.

Further Investigation / Defintive Care

Results of the above examinations, and findings in other body regions, determine the subsequent disposition of the trauma patient.

Further investigations may include:

  • CT scan

  • Angiography

  • Oesophagoscopy / oesophagram

  • Bronchoscopy



Definitive care may include:

  • Chest Drain
  • Thoracotomy

  • Thoracotomy
  • Transfer to critical care area for ventilation / observation


trauma.org 9:2, February 2004

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