trauma_chest
Table of Contents
trauma to the chest
see also:
suspected cardiac tamponade
- early FAST ultrasound scanning is critical in detection of traumatic cardiac tamponade
- once haemopericardium is detected, look for evidence of tamponade: right atrial and right ventricular collapse
- time course of stability is unpredictable as non-linear course in pericardial pressure-volume relationship
- aggressive iv fluid resuscitation may increase rate of development of tamponade and precipitate sudden loss in cardiac output
- if possible, rapid sequence induction (RSI) for emergency intubation should coincide with ability to undertake immediate thoracotomy as hypotension and cardiac arrest is common following induction of general anaesthesia in patients with cardiac tamponade.1)
- in a trauma centre, unresponsive hypotension with systolic BP < 70mmHg and a FAST positive for pericardial tamponade is a consensus-based indication for immediate resuscitative thoracotomy.
- pericardial aspiration can be used as a temporarizing measure if there is delay to thoracotomy.
Patients exposed to sudden deceleration such as fall from height > 3m or motor vehicle collisions at > 65kph are at risk of blunt aortic injury (BAI) and may require CT aortogram.
There are no clinical signs or examination findings with sufficient sensitivity or specificity to detect BAI, thus CXR is important in assisting in risk management.
If blunt aortic injury goes undiagnosed, these patients generally sustain an aortic rupture within 24 hours.
indications for CXR
- major trauma, particularly if chest pain, distracting injuries or sudden deceleration
- those who have chest pain following trauma that is clearly not just superficial skin injury
- suspected pneumothorax or rib fracture
indications for CT chest
the major trauma patient who warrants a chest CT scan or endotracheal intubation, should be considered for a “pan-scan” - CT brain, Cx spine, chest, abdo and pelvis, and usually with contrast media for the chest/abdo/pelvis component.
with iv contrast
- see blunt aortic injury (BAI) suggested by either:
- NB. high speed / rapid deceleration mechanism should lower threshold for imaging
- wide mediastinum (supine CXR >8 cm; upright CXR >6 cm)
- obscured aortic knob; abnormal aortic contour
- left “apical cap” (ie, pleural blood above apex of left lung)
- large left hemothorax
- deviation of nasogastric tube rightward
- deviation of trachea rightward and/or right mainstem bronchus downward
- wide left paravertebral stripe
- high clinical suspicion of BAI
- suspicion for posterior dislocation of sternoclavicular joint
- fractures of 1st rib
- significantly unequal pulse / BP in each arm
possibly without iv contrast
- major trauma with evidence of chest injury or high-risk mechanism
- the trauma patient following insertion of thoracostomy tube
- patients with severe chest wall pain, particularly those with pre-existing limited respiratory reserve or who are high risk (eg. elderly)
- any concerning findings are identified on CXR
- the patient has persistent chest pain or dyspnea, or the patient is unable to undergo a thorough clinical examination because of an extrathoracic injury
- fracture scapula as the forces involved are significant and the risk of concomitant intrathoracic injury is high - consider contrast CT as there is some association with blunt aortic injury
- fracture sternum
- many consider it is worth performing an ECG and a CT chest as they are often associated with rib fracture, myocardial contusion, hemopericardium, spinal fracture, retrosternal hematoma, haemothorax, and pneumothorax.
open pneumothorax
- some penetrating chest wounds may remain open, causing a “sucking chest”
- presence of bubbling at the chest wound generally indicates an open pneumothorax
- immediate management:
- seal the wound with a hand, followed by the use of a sterile occlusive dressing.
- tape the dressing securely on three sides.
- leave the fourth side untaped so that if a tension pneumothorax occurs, the air will leak out during expiration.
- during inspiration the dressing is sucked into the wound, effectively sealing the hole.
- if signs of a tension pneumothorax appear, the dressing should be removed temporarily to allow venting to occur.
- as soon as possible after sealing an open chest wound a formal thoracostomy tube should be inserted
tension pneumothorax
- tension pneumothorax tends to cause death through respiratory failure in the non-ventilated patient, and via impaired cardiac output in the ventilated patient
- tracheal deviation is not a reliable sign
- absence of breath sounds may be misleading, one should ausculate in the axilla
- bilateral decompression of the pleural spaces is indicated when the cause of loss of cardiac output or cardiac arrest is unclear
- prompt pleural decompression via thoracostomy tube on the apparent affected side should be done before CXR if either:
- SBP < 100mmHg despite iv fluids
- SaO2 < 90% when intubated on FiO2 100%
- palpable sub-cutaneous emphysema in axilla coupled with circulatory compromise
- tension is particularly a risk following positive pressure ventilation in the trauma patient
- prehospital prophylactic chest decompression for ventilated patients with chest trauma, using a lateral rather than an anterior approach, may decrease the incidence of untreated tension pneumothorax2)
- traditional immediate Mx since WWII has been decompression by inserting a large bore (at least 16 gauge) needle in the second intercostal space midclavicular line.
- however, needle thoracocentesis is an unreliable means of decompressing the chest of an unstable patient and should only be used as a technique of last resort.3)
- false negatives occur if needle placement does not reach the pleural space
- false positives occur if needle placement is into s/c emphysema or intrapulmonary (eg. bronchial tree or a bulla)
- in a study, only 5% of patients had relief from needle thoracocentesis
- as soon as possible:
- blunt dissection and digital decompression through the pleura is the essential first step for pleural decompression, as decompression of the pleural space is a primary goal during reception of the haemodynamically unstable patient with a haemothorax or pneumothorax.
- drainage and insertion of a thoracostomy tube is a secondary priority
haemothorax
- the ipsilateral chest is dull to percussion if massive haemothorax
- inserting a thoracostomy tube may release a tamponade effect on the bleeding points, so it is essential to restore adequate intravascular volume as soon as possible.
- ensure urgent crossmatch has been arranged as part of the trauma call.
- a thoracotomy may need to be performed if the initial drainage of blood is 1500 mL or more, or if the ongoing loss is 200mL/hour or more.
fractured ribs
- see fractured ribs
- fractured ribs are often well visualised on CXR, but may be poorly shown or not detectable on plain CXR or even rib views - ~50% of fractures are missed on CXR
- patients with high impact injuries to the thorax (eg. fall from a roof), or high risk patients with poor respiratory reserve (eg. elderly), should have a low threshold for having a CT thorax performed as this may detect otherwise undiagnosed flail segments and haemothoraces which may have a propensity to cause the patient's condition to deteriorate over the next few hours.
- patients with isolated rib fractures:
- Mx is generally aimed at:
- analgesia (may need intercostal block)
- preventing secondary pneumonia from poor respiration
- consider prophylactic antibiotics in smokers, those with chronic lung disease and the elderly
- patients with three or more rib fractures, especially elderly patients, are at significant risk for complications, such as pulmonary contusion and pneumonia, even in the absence of other injuries, and should be admitted for observation
- patients with fracture 1st rib
- these patients are at risk of neurovascular injury and should be considered for contrast CT chest
flail chest
- see flail chest
- the flail segment moves paradoxically (ie. moves in when the rest of the chest is expanding and out when the rest of the chest is moving in).
- this paradox will only be present in the spontaneously breathing patient, as mechanical ventilation will cause all segments to move the same way at the same time.
- a flail chest is invariably associated with underlying lung contusion.
- many can be managed with analgesia, and careful fluid administration.
- if ventilation appears inadequate, consideration should be given to early mechanical ventilation.
- the requirement for this is not related to the size of the flail alone, but rather to the underlying lung contusion.
- respiratory function will usually deteriorate over the first 24–48 hours after a lung contusion.
- stabilization of the segment with manual or object pressure restricts chest wall expansion thereby interfering with proper respiratory mechanics and is NO LONGER USED.
sternoclavicular joint dislocation
- posterior SC joint dislocations can cause significant internal injury such as:
- tracheal compression
- lacerate or occlude the subclavian or brachiocephalic vessels
- damage the lung parenchyma causing a pneumothorax
- injure the laryngeal nerve (which may present as hoarseness)
- check pulses in the affected extremity
- if suspect posterior SC dislocation , consider contrast CT chest
- anterior subluxations and dislocations are generally benign, although should be reduced within 12-24hrs
fracture sternum
- CXR and dedicated sternal view
- ECG
- NB. sternal fractures from car accidents (usually from the steering wheel) is NOT associated with increased mortality or major injury if a seat belt was worn (VSTR data)
- consider CT chest as often associated with rib fracture, myocardial contusion, hemopericardium, spinal fracture, retrosternal hematoma, hemothorax, and pneumothorax
- consider troponin
- raised troponin, unexplained persistent tachycardia, new bundle branch block, or dysrhythmia raise concern for cardiac contusion and patients with such findings should be admitted for cardiac monitoring and possibly echocardiography
- cardiac monitoring not generally needed if stable, troponin and ECG is normal
- admit for observation if elderly, severe pain, or poor pulmonary reserve.
potential indications for emergent thoracic surgery in blunt chest trauma
- NB. thoracic surgery and thoracotomy is indicated in only 5—10% of patients sustaining major blunt thoracic injury.
- in some centres, videothoracoscopy has reduced the number of thoracotomies performed
- a persistent massive air leak following chest tube insertion
- a massive haemothorax or continued high rate of blood loss via the chest tube
- ie. 1500 mL of blood upon chest tube insertion or continued loss of 250 mL/h for 3 consecutive hours
- radiographically or endoscopically confirmed tracheal, major bronchial, or esophageal injury
- recovery of gastrointestinal tract contents via the chest tube
- cardiac tamponade
- radiographic confirmation of a great vessel injury
- embolism into the pulmonary artery or heart
- blunt diaphragmatic injuries
- traumatic disruption with loss of chest wall integrity
trauma_chest.txt · Last modified: 2020/07/06 00:30 by gary1