CHEST TRAUMA

CHEST TRAUMA

Causes and introduction of chest trauma

Chest injuries may be blunt or penetrating blast injuries frequently involve a combination of these

Fewer than 15% of chest injuries require surgery tube thoracostomy ,blood or fluid replacement oxygen therapy and analgesia are the mainstay of treatment in most patients hypoxia is the final common pathway of most chest injuries and all patient should receive oxygen at an FIO2 of at least 0 .85 -
Specific chest injuries

Uncomplicated rib fracture

A common injury pain impedes respiration facilitating retention of secretions atelectasis and infection particularly in those with pre-existing respiratory disease injury to the upper ribs 1-3 usually implies severe injury

Ribs 4-9 sustain the majority of injuries
localized pain tenderness and crepitus indicate a fracture an erect plain X rays must be performed to identify associated injuries rather than to accurately identify fracture
A short course  of non -steroidal analgesics may be given if not contraindicated alternatively local infiltration of the fractureswith bupivicaine or thoracic epidural may be necessary

  Simple pneumothorax
 
 Lung laceration caused by blunt or penetrating injury is the most common cause

Air in the pleural space results in lung collapse and a consequent ventilation perfusion mismatch reduce hemithorax movements dyspnoea hyper-resonance and reduced breath sounds

Are usually detected an erect CXR will show the collapsed lung but needle aspiration will establish the diagnosis if the patient is in extremis

Pneumothorax associated with other injuries should be treated using an intercostal tube drain via the fourth or fifth intercostal space general anaesthesia ventilation and air transport should not be undertaken untill a drain has been inserted
Open pneumothorax

Most penetrating wounds close themselves but large defects
 may persist causing a sucking chest wound and impairing ventilation the defect should be covered by a large occlusive dressing (taped on three sides to create a flutter valve ,allowing air to escape during expiration)untill surgical closure can be performed

Tension pneumothorax

A one way valve effect occurs allowing air to pass into the pleural space either from the lung or through the chest wall

The lung collapses and the mediastinum is displaced towards the opposite hemithorax further impairing ventilation and impeding venous return

Cardinal signs
Dyspnoea ,cyanosis tracheal deviation ,hyperresonance absent breathe sounds and raised venous pressure are the cardinal signs

 Immediate decompression should be performed by inserting a needle into the second intercostal space in the midclavicular line a formal intercostal tube drain should be inserted as soon as possible

Flail segment or chest

This occurs where multiple rib fractures allow an island of chest wall to move independently of the rest of the chest wall

 The free floating segment moves paradoxically reducing the efficiency of the chest wall excursion in expanding and deflating the lung

,More important however is the injury to the underlying lung which is the more potent cause of hypoxia dypsnoea poor chest movement

The identification of segment moving paradoxically and crepitus of rib or cartilage fractures are the physical sign a CXR may show multiple fractures
Patient with flail chest often compensate adequately in the first 24-48 hours and then rapidly develop respiratory failure
Treatment
 Includes adequate analgesia oxygen therapy intravenous fluid (avoid over hydration) intercostal tube drainage may be necessary if there is a co-existing pneumothorax ,ventilation may be necessary if respiratory failure supervenese
Haemothorax

Massive haemothorax blood loss more than 1500 ml  occurs following disruption of major intra thoracic vessels usually by a penetrating wound

Poor respiratory movement dullness to percussion absent breath sounds and shock are prominent an erect CXR is required to detect even the presence of large volumes of blood 
pneumothorax my co-exist

Intravenous lines for transfusion are necessary and a large bore intercostal drain is placed to drain the dependent area of the thorax

Continuous blood loss of 200-300 ml|h necessitates thoracotomy wounds medial to the nipple or the scapula indicate possible mediastinal trauma

Pulmonary contusion

Localized aedema may results from blunt trauma , but widespread pulmonary oedema may also occurs in response
 to primary lung injury in the presence of normal cardiac filling pressure (ARDS)the alveolar transudate impedes gas exchange resulting in respiratory failure ventilation may become necessary especially in those with pre-existing  pulmonary disease, impaired consciousness other concomitant injuries and multisystem organ failure


Penetrating tracheal injuries are often associated with oesophageal carotid and jugular injuries and require prompt surgical exploration and repair a major bronchial injury in unusual and often fatal

Patients present with haemoptysis surgical emphysema and pneumothorax a persisting large air leakage after intercostal tube drainage suggests bronchial injury

Surgical repair in necessary in most patients


This is usually results from a penetrating injury
 
 Physical signs
Include hypotension raised venous pressure muffled heart sounds and pulsus paradoxus pericardiocentesis should be attempted but open pericardiotomy and arrest haemorrhage may be required


Is the most common cause of death following major trauma and usually occurs at the ligamentum arteriosum or aortic root in survivors a thin layer of adventitia persists and a contained haematoma extends into the mediastinum A CXR showing a widened mediastinum id often the first indication and ct scanning should be performed to confirm the diagnosis immediate surgical repair is necessary


Blunt trauma especially to the left chest wall is the usual mechanism premature ventricular contraction st segment changes sinus tachycardia and right bundle branch block may be evident on the ECG and sudden dysrhythmias may supervene serum troponin levels may indicate myocardial damage


Penetrating trauma usually by instrumentation is the commonest injury but forced ejection of gastric contents into oesophagus with the glottis closed may lead to oesophageal rupture (Boerhaave,s syndrome mediastinitis and empyema follow and are usually fatal left haemothorax or pneumothorax without rib fractures or the presence of mediastinal air suggest, and gastrografin swallow confirms the diagnosis tube drainage and antibiotic with subsequent direct surgical repair of the defect should be undertaken if possible


Blunt trauma usually to the abdomen causes large radial tears leading to immediate herniation and respiratory embarrassment over 90%are on the left side penetrating injuries produce small defect that don not usually cause immediate herniation the diagnosis is frequently missed but the  chest X ray (CXR) may reveal viscera in the chest surgical repair is necessary




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