THE KURSK STATE MEDICAL UNIVERSITY
DEPARTMENT OF SURGICAL DISEASES № 1
THORACIC TRAUMA
Information for self-training of English-speaking students
The chair of surgical diseases N 1 (Chair-head - prof. S.V.Ivanov)
BY ASS. PROFESSOR I.S. IVANOV
KURSK-2010

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INITIAL MANAGEMENT OF THE ACUTELY INJURED PATIENT
Priorities
Initial care of the injured patient necessitates two assumptions: that the patient may have more than one injury, and that the obvious injury is not necessarily the most important one. Successful resuscitation requires an approach predicated on prioritizing injuries. A simple method of prioritization includes four categories of injury:
1. Exigent—the most life-threatening conditions, requiring instantaneous intervention
(e.g., laryngeal fracture with complete upper airway obstruction and tension pneumothorax)
2. Emergency—those conditions requiring immediate intervention, certainly within the first hour (e.g., ongoing hemorrhage and intracranial mass lesions)
3. Urgent—those conditions requiring intervention within the first few hours (e.g., open contaminated fractures, ischemic extremity, and hollow viscous injuries)
4. Deferrable—those conditions that may or may not be immediately apparent but will subsequently require treatment (e.g., urethral disruption and facial fractures)
Use of this scheme requires a deliberate and regimented approach to the resuscitation, while retaining the flexibility to reset the priorities depending on the diagnostic disclosures that arise during the resuscitation. The maintenance of this balance between a structured resuscitation protocol and the need to change direction properly generate the necessity for one person to be in charge of the entire resuscitation procedure.
Steps In The Initial Resuscitation
Airway. The crucial first step in managing an injured patient is securing an adequate airway. The mechanical removal of debris and the chin lift or jaw thrust maneuvers, both of which pull the tongue and oral musculature forward from the pharynx, are often useful in clearing the airway of less severely injured patients. However, if there is any question about the adequacy of the airway, if there is evidence of severe head injury, or if the patient is in profound shock, more definitive airway control is appropriate. In the vast majority of patients this involves endotracheal intubation. Unfortunately, control of the airway is sometimes more complex than simply placing an endotracheal tube. The

3 presence of cervical spine injury in the unconscious patient is always a possibility, and injudicious movement of the neck in the process of endotracheal intubation can be devastating.
Endotracheal intubation, the most direct method for establishing an airway, requires that the head and neck be held in a neutral position to avoid exacerbation of potential cervical spine injury and that the spine be stabilized until an injury has been definitively ruled out. If the patient has no evidence of soft tissue or bony injury to the midface, and is breathing spontaneously, nasotracheal intubation is an acceptable alternative to orotracheal intubation.
In a few patients, a surgical airway may be required. Although classic tracheostomy may be indicated in select patients, such as those with laryngeal injuries, cricothyroidotomy is generally the preferable emergency procedure. These surgical procedures may be preceded by needle cricothyroidotomy with jet insufflation to improve oxygenation and allow the surgical procedure to be performed in a more orderly fashion.
Breathing. If there is decreased respiratory drive or an unstable chest wall, assisted ventilation is usually necessary. The three most common reasons for ineffective ventilation following successful placement of an airway are malposition of the endotracheal tube, pneumothorax, and hemothorax. Therefore, palpation and auscultation of the chest are necessary diagnostic adjuncts at this point. A supine
(anteroposterior [AP]) chest x-ray examination can validate the physical examination and better define chest wall and plural abnormalities. Although there is usually time to perform a chest radiograph prior to invasive therapeutic procedures, in the patient with profound hemodynamic instability and a high suspicion of tension pneumothorax, a needle catheter decompression can be both diagnostic and therapeutic. Under these circumstances decompression of the chest before the radiograph is appropriate.
Circulation. When possible, control of the hemorrhage precedes placement of the intravenous lines. This may be as simple as a compressive dressing over a bleeding wound or large vessel or may require broader compression, such as application of a pneumatic antishock garment in the patient who has an obvious pelvic fracture.

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Intravenous cannulas are usually placed percutaneously in the arm or groin. They should be large bore, and a minimum of two should be placed. Lines should not be inserted distal to extremity wounds with potential vascular injury. Alternatives are cutdown by either the antecubital or saphenous route, or intraosseus in children under the age of 3. With the exception of the use of the large (8 French) introducer catheter, subclavian venipuncture is not a rapid route for fluid administration and is best reserved for monitoring response to fluid therapy. Fluid resuscitation begins with a 1000-ml. bolus of lactated Ringer's solution for an adult, or 20 ml. per kg. for a child. Response to therapy is monitored by skin perfusion, urinary output, and central venous pressure readings when that line has been placed.
Disability/Neurologic Assessment. At this juncture, a brief examination to determine level of consciousness, pupillary response, and movement of extremities is a necessary prelude to the determination of severity of neurologic injury. In addition, this information becomes initial data in the computation of the Glasgow Coma Scale (GCS), which is a method of both following the evolution of neurologic disability and prognosticating future recovery. It is worth noting that pupillary response can still be assessed in the paralyzed patient. In recording the GCS in intubated and paralyzed patients, the authors have added the modifiers T and P (intubated and paralyzed, respectively) to signify that the score may be inaccurate.
Exposure for Complete Examination. By this point, most injuries that are either exigent or emergencies have been recognized and treated. The next step is to completely, but expeditiously, re-examine the patient to diagnose other injuries. Complete physical examination is typically done in a head-to-toe manner and includes ordering and collecting data from appropriate laboratory and radiologic tests. Data accumulated can then be used to reset priorities. This time period also allows for the placement of additional lines, catheters (nasogastric, Foley), and monitoring devices. When the patient is oxygenating, ventilating, and perfusing adequately, a priority plan should be established for subsequent treatment.
RECOGNITION AND MANAGEMENT OF SPECIFIC INJURIES

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Management of Specific Injuries
TRACHEA AND LARYNX
Penetrating tracheal wounds are usually readily apparent and dramatic in their clinical presentation, with subcutaneous emphysema, crepitus, or hemoptysis as presenting signs. Early endotracheal intubation by field paramedics may, however, mask a high tracheal injury. Indications for primary surgical repair depend on the severity of the injury; hence, careful endoscopic or surgical evaluation is required. When repair is needed, the principles include dйbridement of devitalized cartilage, mucosal coverage of exposed cartilage, and closure of tracheal defects. Tracheostomy is not always required following a tracheal repair but certainly is useful if extensive edema or prolonged airway compression is anticipated.
Blunt laryngotracheal injuries are not always obvious and are easily overlooked in the multiple trauma victim. These patients may initially appear deceptively normal, only to suddenly develop severe respiratory distress. Physical examination, flexible fiberoptic endoscopy, and CT may help access the neck for blunt laryngotracheal injury.
Equipment for emergency tracheostomy must always be readily at hand. If emergency airway is required, direct endotracheal intubation may be attempted if the laryngeal structures are well visualized, aided by passing the endotracheal tube over a flexible endoscope. However, even in the most experienced hands this may be impossible and may risk worsening the tracheal injury. Tracheostomy is therefore usually recommended as an emergency airway following blunt laryngotracheal injuries, even though it also carries risk of further injury. The basic principles of repairing tracheal injuries are primary closure of mucosal lacerations and reduction of cartilaginous fractures. Mucosal repairs should be performed with fine absorbable suture. Simple lacerations of the subglottic trachea can generally be primarily repaired with simple

6 nonabsorbable sutures. If the defect cannot be primarily closed, tracheal mobilization may bridge a gap of several tracheal rings. Controversial areas in the surgical care of laryngotracheal trauma patients include the timing of operation, the role of laryngeal stents, the use of steroids, indications for skin grafting, and the techniques of operative exposure of the larynx.
PHARYNX AND ESOPHAGUS
Injuries to the esophagus are most difficult to diagnose. The sensitivity of esophagography in detecting esophageal injury varies from approximately 50% to 90%; the sensitivity of endoscopy varies from 29% to 83%. 25 These modalities should be considered complementary, and when combined, have an accuracy of nearly 100%. Operative exposure of the esophagus can be difficult. The morbidity and mortality of a missed esophageal injury demands a high index of suspicion, since virtually all reported deaths from cervical esophageal injuries are the result of a delayed or missed diagnosis. When injured, the structures may be repaired primarily in two layers using absorbable and nonabsorbable suture. It is important to drain all such wounds, because infection or salivary fistula is not an infrequent complication. If there is massive loss of tissue, as with a shotgun blast, it may be necessary to perform a cutaneous esophagostomy for feeding purposes and a cutaneous pharyngostomy for salivary drainage. A secondary reconstructive procedure is then required after the initial healing is complete. Most surgeons advocate primary repair of all esophageal injuries if accomplished early.
Delays of greater than 12 hours significantly increase the risk of repair dehiscence, wound abscess, and death. Neck esophageal injuries diagnosed more than 24 to 48 hours after injury are best managed initially by diversion and drainage.
Thorax
One quarter of civilian trauma deaths are caused by thoracic trauma, and two thirds of these deaths occur after the patient reaches the hospital. Mortality rates of hospitalized patients with an isolated chest injury range from 4% to 8%; they increase to 10% to
50% when one other organ system is involved and rise to 35% when multiple additional

7 organ systems are involved. Many of these deaths can be prevented with prompt diagnosis and correct management. Despite these high mortality rates, most thoracic injuries do not require a thoracotomy but rather simple lifesaving maneuvers of airway control and tube thoracostomy.
Mechanism of Injury
The life-threatening injuries incurred in penetrating trauma are distinctly different from those of blunt injuries. Penetrating thoracic injuries (e.g., stab wounds, gunshot wounds, and impalement on a foreign body) primarily injure the peripheral lung, producing both a hemothorax and pneumothorax. More than 80% of all penetrating chest wounds cause a hemothorax, and nearly all cause a pneumothorax. Penetrating injuries that enter or traverse the mediastinum must also be evaluated for potential cardiac, great vessel, or esophageal injury. Hemodynamically unstable patients with mediastinal entering or traversing wounds should be considered to have exsanguinating thoracic hemorrhage, pericardial tamponade, or tension pneumothorax. Preparation for immediate thoracotomy is indicated.
Blunt trauma can induce injury by three distinct mechanisms: a direct blow to the chest
(e.g., rib fracture), deceleration injury (e.g., pulmonary or cardiac contusion and aortic tear), and compression injury (e.g., cardiac and diaphragm rupture). Rib fracture is the most common sign of blunt thoracic trauma. The less common fractures of the scapula, sternum, or first rib suggest massive force of injury and should invoke a thorough search for multisystem injury. In adults the bony thoracic cage absorbs much of the shock of blunt trauma. In children, the flexible cartilaginous thoracic structures allow the transmission of blunt force to the intrathoracic structures, resulting in a higher incidence of pulmonary contusion than of rib fractures.
CHEST WALL
Rib Fractures. Fracture of the ribs is the most common thoracic injury
With simple fractures, pain on inspiration is the principal symptom. Localized pain, tenderness, and occasionally crepitus confirm the diagnosis. A chest x-ray should be obtained to exclude other intrathoracic injuries and not necessarily to identify a rib

8 fracture. The use of narcotics in small amounts, intercostal nerve blocks, and muscle relaxants are usually adequate treatment. Hospital admission for pain relief, cough assistance, and endotracheal suction may be necessary for several days, particularly in elderly patients. Underestimating the pathophysiologic effect of simple rib fracture, particularly in the elderly patient, is one of the primary pitfalls in trauma care. Rib belts and adhesive taping, although once popular, should be avoided because the resultant limitation in motion increases the incidence of retained secretions and atelectasis.
Fracture of the upper ribs (1 through 3), clavicle, or scapula implies significant trauma, and associated major vascular injury must be suspected, although this exact association has been questioned. One report documents a 14% incidence of vascular injury in patients sustaining first rib fractures. All had associated absent pulse, brachial plexus injury, or a displaced fracture, implying that angiography may be selectively employed in this group of patients.
Flail Chest. Unilateral fracture of four or more ribs anteriorly and posteriorly or bilateral anterior or costochondral fracture of four or five ribs produces enough instability that paradoxical respiratory motion results in hypoventilation of an unacceptable degree .
Although usually visually apparent in the unconscious patient, because of splinting, the flail segment may not be readily apparent in the conscious patient. If severe and untreated, atelectasis, hypercapnia, hypoxia, accumulations of secretions, and ineffective cough occur. The pathophysiologic effects may be present immediately or may progress over several hours and present as late respiratory decompensation.
Excellent pain relief and improved ventilation can often be provided by a segmental epidural anesthetic or serial intercostal rib blocks. Intrapleural anesthetic administration
(usually via a previously placed chest tube) rarely provides adequate pain relief.
If spontaneous respirations prove inadequate, endotracheal intubation with the use of a volume respirator has largely supplanted attempts at stabilization of the chest wall. A respiratory rate of more than 40 breaths per minute and a PO 2 of less than 60 mm. Hg on 60% FIO 2 are indications for intubation and mechanical ventilation. The presence of pre-existing chronic lung disease, depressed level of consciousness, and concomitant

9 intra-abdominal injuries are also relative indications for intubation. Only rarely is sternal fracture displacement or rib overlap and displacement severe enough to warrant open reduction and internal fixation.
Respiratory difficulty in flail chest injury is invariably aggravated by an underlying pulmonary contusion. Investigators have concluded that the major respiratory problem is the underlying pulmonary injury and that paradoxical movement is a minor factor.
These studies demonstrate a reduced need for mechanical ventilation if care is exercised in avoiding fluid overresuscitation. If intubation is required, positive end-expiratory pressure (PEEP) may be helpful in restoring functional residual capacity and reducing intrapulmonary shunts. Mechanical ventilation and a better understanding of the underlying pulmonary contusion have reduced the mortality of flail chest from 50% to less than 5%.
Open Pneumothorax. A defect in the chest wall provides a direct communication of the pleural space with the environment. A wound large enough to exceed the laryngeal crosssectional area provides an alternative air pathway with less resistance than that of the normal tracheobronchial tree. Inability to generate negative intrathoracic pressure causes lung collapse and marked paroxysmal shifting of the mediastinum with each respiratory effort. The resultant hypoventilation and diminished cardiac output can become immediately life-threatening. Diagnosis is readily apparent, as each aspiration draws air into the interpleural space, causing the characteristic sucking chest wound. Treatment consists of prompt closure of the defect with a sterile dressing followed by venting of the chest with either a flutter valve or chest tube to treat the possibly resultant tension pneumothorax.
Primary Survey
The principal aim of the primary survey is to identify and treat immediately life-threatening conditions. The lifethreatening chest injuries are:
1.
Tension Pneumothorax
2.
Massive Haemothorax
3.
Open Pneumothorax
4.
Cardiac Tamponade
5.
Flail chest

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Monitoring Adjuncts
1.
Oxygen Saturation
2.
End-tidal CO2 (if intubated)
Diagnostic Adjuncts
1.
Chest X-ray
2.
3.
FAST ultrasound
Arterial Blood Gas
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:
1.
Rib Fractures & flail chest
2.
Pulmonary contusion
3.
Simple pneumothorax
4.
Simple haemothorax
5.
Blunt aortic injury
6.
Blunt myocardial injury
Tension
Pneumothorax
Simple
Pneumothorax
Trachea
Away
Expansion
Decreased.
Chest may be fixed in hyper-expansion
Breath Sounds
Diminshed or absent
Midline Decreased May be diminished
Percussion
Hyper-resonant
May be hyperresonant. Usually

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Haemothorax
Pulmonary
Contusion
Midline
Midline
Decreased
Normal
Diminished if large.
Normal if small
Normal. May have crackles normal
Dull, especially posteriorly
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.
Chest Trauma
Pulmonary Contusion
Pulmonary contusion is an injury to lung parenchyma, leading to oedema and blood collecting in alveolar spaces and loss of normal lung structure & function. This blunt lung injury develops over the course of 24 hours, leading to poor gas exchange, increased pulmonary vascular resistance and decreased lung compliance. There is also a significant inflammatory reaction to blood components in the lung, and 50-60% of patients with significant pulmonary contusions will develop bilateral Acute Respiratory Distress Syndrome (ARDS).
Pulmonary contusions occur in approximately 20% of blunt trauma patients with an Injury Severity Score over
15, and it is the most common chest injury in children. The reported mortality ranges from 10 to 25%, and 40-
60% of patients will require mechanical ventilation. The complications of pulmonary contusion are ARDS, as mentioned, and respiratory failure, atelectasis and pneumonia.
Diagnosis
Pulmonary contusions are rarely diagnosed on physical examination. The mechanism of injury may suggest blunt chest trauma, and there may be obvious signs of chest wall trauma such as bruising, rib fractures or flail chest. These suggest the presence of an underlying pulmonary contusion. Crackles may be heard on auscultation but are rarely heard in the emergency room and are non-specific.
Severe bilateral pulmonary contusions may present with hypoxia - but more usually hypoxia develops as the pulmonary contusions blossom or as a result of subsequent ARDS.
Chest X-ray
Most significant pulmonary contusions are diagnosed on plain chest X-ray. However the chest X-ray will often under-estimate the size of the contusion and tends to lag behind the clinical picture. Often the true extent of injury is not apparent on plain films until 24-48 hours following injury.
Computed Tomography
Computed tomography (CT) is very sensitive for identification of pulmonary contusion, and may allow differentiation from areas of atelectasis or aspiration. CT also allows for 3-dimensional assessment and calculation of the size of contusions. However, most contusions that are visible only on a CT scan are not clinically relevant, in that they are not large enough to impair gas exchange and do not worsen outcome.
Nevertheless, CT will accurately reflect the extent of lung injury when pulmonary contusion is present.
Management
Managment of pulmonary contusion is supportive while the pulmonary contusion resolves. Most contusions will require no specific therapy. However large contusions may affect gas exchange and result in hypoxaemia. As

12 the physiological impact of the ocntusions tends to develop over 24-48 hours, close monitoring is required and supplemental oxygen should be administered.
Many of these patients will also have a significant chest wall injury, pain from which will affect their ability to ventilate and to clear secretions. Management of a blunt chest injury therefore includes adequate and appropriate analgesia. Tracheal intubation and mechanical ventilation may be necessary if there is difficulty in oxygenation or ventilation. Usually ventilatory support can be discontinued once the pulmonary contusion has resolved, irrespective of the chest wall injury.
The classic management of pulmonary contusion includes fluid restriction. Much of the data to support this comes from animal models of isolated pulmonary contusion. However, while relative fluid excess and pulmonary oedema will augment any respiratory insufficience, the consequences of the opposite - hypovolaemia are more severe and long-lasting. Prolonged episode of hypoperfusion in trauma patients will result in inflammatory activation and acute lung injury, and may result in ARDS and multiple organ failure. Hence the goal for management of patients with pulmonary contusion should be euvolaemia.
Complications
Pulmonary contusions will usually resolve in 3 to 5 days, provided no secondary insult occurs. The main complications of pulmonary contusion are ARDS and pneumonia. Approximately 50% of patients with pulmonary contusion develop ARDS, and 80% of patients with pulmonary contusions involving over 20% of lung volume.
Direct lung trauma, alveolar hypoxia and blood in the alveolar spaces are all major activators of the inflammatory pathways that result in acute lung injury.
Pneumonia is also a common complication of pulmonary contusion, blood in the alveolar spaces providing an excellent culture medium for bacteria. Clearance of secretions is decreased with pulmonary contusion, and this is augmented by any chest wall injury and mechanical ventilation. Good tracheal toilet and pulmonary care is essential to minimise the incidence of pneumonia in this susceptible group.
Haemothorax
Haemothorax is a collection of blood in the pleural space and may be caused by blunt or penetrating trauma.
Most haemothoraces are the result of rib fractures, lung parenchymal and minor venous injuries, and as such are self-limiting. Less commonly there is an arterial injury, which is more likely to require surgical repair.
Diagnosis
Most small-moderate haemothoraces are not detectable by physical examination and will be identified only on
Chest X-ray, FAST or CT scan. However, larger and more clinically significant haemothoraces may be identified clinically. If a large haemothorax is detected clinically it should be treated promptly.
Physical examination
Chest examination may indicate the presence of significant thoracic trauma with external bruising or lacerations, or palpable crepitus indicating the presence of rib fractures. There may be evidence of a penetrating injury over the affected hemithorax. Don't forget to examine the back!
The classic signs of a haemothorax are decreased chest expansion, dullness to percussion and reduced breath sounds in the affected hemithorax. There is no mediastinal or tracheal deviation unless there is a massive haemothorax. All these clinical signs may be subtle or absent in the supine trauma patient in the emergency department, and most haemothoraces will only be diagnosed after imaging studies.
Chest X-ray
Chest X-ray remains the standard test for diagnosis of thoracic trauma in the emergency department. In the erect patient (penetrating injury), the classical picture of a fluid level with a meniscus is seen. Although the

13 erect film is more sensitive, it takes approximately 400-500mls of blood to obliterate the costo-phrenic angle on a chest radiograph.
In the supine position (most blunt trauma patients) no fluid level is visible as the blood lies posteriorly along the posterior chest. The chest X-ray shows a diffuse opacification of the hemithorax, through which lung markings can be seen. It may be difficult to differentiate a unilateral haemothorax from a pneumothorax on the opposite side.
It may be difficult to detect small amounts of blood (< 200mls) on the plain chest radiograph. Emergency room ultrasound examination can detect smaller haemothoraces, although in the presence of a pneumothorax or subcutaneous air ultrasound may be difficult or inaccurrate. When examining the right and left upper quadrants, the examiner can usually view above the diaphragms to identify any fluid collections.
Computed Tomography
Most cases of thoracic trauma do not require computed tomography (CT). CT is more sensitive than the plain chest radiograph in diagnosing haemothoraces. However, CT can be invaluable in determining the presence and significance of a haemothorax, especially in the blunt, supine trauma patient who may have multiple thoracic injuries. Small amounts of blood are detectable and can be localised to specific areas of the thoracic cavity. The significance of CT-only detectable haemothoraces is not entirely clear, and certainly some of these will require no treatment. CT may also be useful in differentiating haemothorax from other thoracic pathology such as pulmonary contusion or aspiration.
Management
Chest drain
Chest tube placement is the first step in the management of traumatic haemothorax. The majority of haemothoraces have already stopped bleeding and simple drainage is all that is required. All chest tubes placed for trauma should be of sufficient calibre to drain haemothoraces without clotting. Hence the smallest acceptable size for an adult patient is 32F, and preferably 36F tubes should be placed.
Chest drains for simple haemothorax can be placed posteriorly. However if there is concomitant pneumothorax, or patients have multiple rib fractures with positive pressureventilation, drains should be placed anteriorly to avoid tension pneumothorax for an obstructed chest tube.
Thoracotomy
Thoracotomy is required in under 10% of thoracic trauma patients. Most haemothoraces stem from injury to lung parenchyma or venous injury and will stop bleeding without intervention. Penetrating trauma is more likely to be associated with arterial haemorrhage requiring surgery.
The indications for thoracotomy are usually quoted as the immediate drainage of 1000-1500mls of blood from a hemithorax. However the initial volume of blood drained is not as important as the amount of on-going bleeding. If the patient remains haemodynamically stable they may be admitted and observed. The colour of the blood is also important - dark, venous blood being more likely to cease spontaneously than bright red arterial blood. Patients admitted for observation who have continuing drainage with no signs of reduction in chest tube output over 4-5 hours should also undergo thoracotomy. The threshold for this is usually stated at around 200-
250mls of blood per hour.

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Complications
Retained Haemothorax, Empyema
Failure to adequately drain a haemothorax initially results in residual, clotted haemothorax which will not drain via a chest tube. If left untreated, these retained haemothoraces may become infected and lead to empyema formation. Even if they remain uninfected, the clot will organise and fibrose, resulting in a loss of lung volume which may result in impaired pulmonary function. Failure to adequately drain a haemothorax is due to failure to initially diagnose the haemothorax or inadequately draining the haemothorax (small chest tube, incorrect placement, clotted tube).
Diagnosis of retained haemothorax is usually made on CT, which shows one or more loculated collections of blood. Surgery is indicated if there is evidence of empyema (fever, raised white cell count, air-fluid levels on
CT), or if the haemothorax is large enough to cause lung volume loss. Surgery if possible should be performed early, within the first 3-7 days following injury. At this time the clot can be cleared with thoracoscopy or a minithoracotomy. If clot evacuation is delayed beyond this time the inflammatory reaction in the pleura requires a more formal thoracotomy with removal of this 'peel' and often formal decortication - a much longer and bloodier procedure. At this time there is limited evidence to support the use of thrombolytic therapy to lyse clotting haemothoraces.
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.

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Chest Trauma
Traumatic Aortic Injury
Blunt aortic injury
Up to 15% of all deaths following motor vehicle collisions are due to injury to the thoracic aorta. Many of these patients are dead at scene from complete aortic transection. Patients who survive to the emergency department usually have small tears or partial-thickness tears of the aortic wall with pseudoaneurysm formation.
Most blunt aortic injuries occur in the proximal thoracic aorta, although any portion of the aorta is at risk. The proximal descending aorta, where the relatively mobile aortic arch can move against the fixed descending aorta
(ligamentum arteriousm), is at greatest risk from the shearing forces of sudden deceleration. Thus the aorta is a greatest risk in frontal or side impacts, and falls from heights. Other postulated mechanisms for aortic injury are compression between the sternum and the spine, and sudden increases in intra-luminal aortic pressure at the moment of impact.
Priorities
Patients with blunt aortic injury tend to fall into 3 major categories:
Presentation
Dead
Haemodynamically unstable
Injury Type
Aortic transection / rupture
Haemorrhage from other sites/organs
OR
Aortic haemorrhage
Haemodynamically stable Contained aortic injury
Management priority
Control haemorrhage
Blood pressure control
Most blunt aortic injuries surviving to hospital are partial-transections, and should be managed with blood pressure control until the defintivie repair. Thus the priority in the management of haemodynamically unstable patients with potential aortic injury is to rapidly identify and control on-going haemorrhage from other sites, and to avoid over-resuscitation. Sites of concealed haemorrhage are identified with Chest and Pelvis radiographs and
FAST ultrasound or Diagnostic Peritoneal Lavage.
The caveat to these cases is the patient with and aortic tear and impending rupture. These patients classically present as 'meta-stable' - ie they respond to fluid resuscitation and then drop their blood pressure in a cyclical manner. It is important to recognise this futile cycle early and avoid aggressive cyclical

16 resuscitation, as this will ultimately lead to free fupture of the aorta and an iatrogenic hypothermia & coagulopathy. Beware the 'meta-stable' patient with a widened mediastinum and a
Cranium and Brain
Brain injury, either alone or in combination with other injuries, is the major determinant of survival and functional outcome in most cases of blunt trauma. Two principles guide the initial care of the patient with severe head injuries: immediate and repeated assessment of injury severity, and protection of the brain from further injury. The treatment approach depends on identifying the two fundamental varieties of head injury: focal or diffuse. Focal injuries consist of mass lesions (e.g., epidural or subdural hematoma) that cause neurologic dysfunction, largely by brain compression, and often require surgical evacuation. Diffuse brain injuries are equally frequent and cause prolonged coma without intracranial masses. These do not require specific surgical therapy but can be as devastating as focal injuries.
Initial Management
The ultimate outcome of brain injury is as much (or more) dependent on the early establishment of an airway, ventilation, control of hemorrhage, and restoration of perfusion as any other organ. The previous protocol proposed for resuscitation of the multiply injured patient is equally applicable to the patient with isolated brain injury.
The airway should be secured immediately, taking care to remember that spinal cord injury is present in as many as 10% of head injury patients. The brain is extremely susceptible to lowered perfusion states following injury; consequently, it is critical that adequate arterial pressure, blood volume, and oxygenation be maintained. Resuscitation fluids and blood replacement should be administered to maintain perfusion while avoiding volume overload. It is worth emphasizing that brain injury per se rarely causes hypotension during the early period following trauma, and other causes and sources of blood loss should be sought out.
Assessment of Severity of Injury. The severity of brain injury can be rapidly estimated by determining three factors: level of consciousness, pupillary function, and lateralized weakness of the extremities.

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Level of consciousness is best assessed by the GCS, a system that evaluates eye opening, best motor response, and verbal response . The GCS is determined by taking the best response in each category and totaling them; it ranges from 3 to 15. 59 Because of its repeatability, a difference of two signals a change in neurologic status; a decrease of three usually indicates an enlarging hematoma and demands prompt treatment.
Pupillary function is assessed by the size, equality, and response to bright light.
Whether or not there has been ocular injury, any pupillary asymmetry greater than 1 mm. must be attributed to intracranial injury unless proved otherwise. With few exceptions, the largest pupil is on the side of the mass lesion. The lateralized extremity weakness is detected by testing motor power in patients able to cooperate or by observing symmetry of movement in response to painful stimulus. As the severity of injury becomes worse, lateralized weakness is more difficult to appreciate, and small differences may be important.
The GCS score should be assessed in the field or by the first responders, then reassessed after specific treatment interventions. Because intubation and paralyzing agents alter the ability to assess the components of the GCS, the presence of an endotracheal tube or the recent administration of paralytic agents is noted by the modifiers T and P, respectively, when computing the GCS score.
Protection from Further Insult. Cerebral ischemia is present in more than 90% of patients who die from head trauma and is the most preventable complication. Most ischemic complications occur soon after injury, are much more common when multisystem trauma is present, and can be reversed in the early phases of care. In ischemia, fewer nutrients are reaching the brain than its metabolism demands; therefore, maximizing oxygen and glucose delivery to the brain can offset it. This requires ample blood flow to the brain and adequate concentration of oxygen and glucose in the blood. However, excess fluid resuscitation or blood pressure elevation must be avoided, because the cerebral vessels do not react normally after injury; they fail to constrict if subjected to elevated blood pressure. Invasive monitoring devices such as Swan-Ganz right heart

18 catheterization and intracranial pressure (ICP) monitoring may be necessary to determine the appropriate fluid requirements and cerebral perfusion pressure.
Arterial oxygen content must be optimized, usually best accomplished by assisting ventilation. Prompt treatment of thoracic causes of hypoxia or hypoventilation (e.g., pneumothorax, hemothorax, and pulmonary contusion) are essential. Endotracheal intubation is often required for definitive treatment of head injuries. If urgent intubation is required, the same techniques that are used in the operating room should be applied.
Failure to use paralytic agents, pharyngeal anesthesia, and barbiturate induction invites massive elevation of the ICP during intubation.
Even after relatively short periods of ischemia, the brain may respond to reperfusion in a pathologic fashion, with prompt and severe brain swelling and marked increases in intracranial pressure. Elevated ICP can best be managed in the early phases of injury by decreasing the intravascular cerebral blood volume. Intravascular cerebral blood volume is best decreased by controlled hyperventilation, because the arterial carbon dioxide concentration is the most potent known regulator of cerebral vessel size.
Decreasing brain water may also be beneficial and is accomplished with diuretics or hyperosmotic agents, the latter being more rapid. However, neither should be used in the underresuscitated patient in whom cerebral perfusion pressure is low.
Definitive Care
Definitive care begins with a definitive diagnosis, which is established exclusively by computed tomography (CT). Cranial CT has a high priority in the evaluation of a patient with altered level of consciousness or lateralizing neurologic signs. It should be performed as soon as cardiorespiratory stability has been achieved and a lateral cervical spine roentgenogram demonstrates no fracture or dislocation. Seriously injured patients who are intubated should receive neuromuscular blockage during the study. A good quality CT scan identifies focal mass lesions and allows the diagnosis of the presence of diffuse brain injury. Focal injuries with significant mass effect require surgical evacuation; patients with these injuries go directly to the operating room. Patients with diffuse brain injury are managed in the intensive care unit. Monitoring devices for ICP

19 are placed for on-line management of intracranial hypertension in both groups.
Definitive care continues, with the principal effort directed toward controlling intracranial hypertension to keep the ICP within normal limits. Therapy is added as necessary to achieve this goal as follows: moderate hyperventilation (PCO 2 30 to 35 mm. Hg), diuretics (furosemide, 20 to 40 mg. three times per day), and finally, hyperosmolar therapy (20% mannitol to keep serum osmolality 295 to 305 mOsm).
Although both barbiturates and glucocorticoids have been advocated in the management of severe head injury, clinical studies do not support their use. Systemic support must be vigorous to ensure continued cerebral oxygenation and to prevent infectious complication of prolonged coma.
Vertebrae and Spinal Cord
The incidence of spinal cord injury in the United States is approximately 50 cases per 1 million population per year. Motor vehicle accidents alone result in more than 500 people with quadriplegia per year. Approximately 6% of all injury hospitalizations are due to vertebrae injuries, and 1% are from spinal cord injuries. 105 Although these injuries represent a small proportion of the total injury-related hospitalizations, they result in significant physical and psychological changes, often requiring long-term and expensive medical treatment and rehabilitation. Average hospital charges for quadriplegic survivors cost $50,000 in 1988. Whereas brain and spinal cord injuries are the primary determinants of long-term disability, many spinal cord injuries are incomplete and, given proper care, may have a remarkable capacity for recovery. Many of the acute problems and complications that the patient with spinal cord injury faces have been identified, and there are effective procedures for preventing or limiting these problems. Rehabilitation programs for patients with spinal cord injuries have also been developed, which help the patient attain the highest possible functional level of recovery.
One review of 300 acute cervical fractures and dislocations reported that motor vehicle accidents (one third), falls (one third), and athletic injuries or missile wounds are the usual causes of injury to the cervical spine. 10 Other reports suggest that motor vehicle

20 accidents are responsible for up to 60% of spinal cord injuries, falls for 20% to 30%, and diving accidents for 5% to 10%. 105 In Bohlman's series, one third of the patients were not diagnosed when first seen in the emergency department. He identified the following four specific categories of patients whose diagnoses were likely to be delayed: (1) patients with head injuries; (2) patients with multiple injuries, including fractures elsewhere; (3) patients with brain injuries and impaired consciousness; and (4) intoxicated patients. Careful follow-up examinations must be made during a traumatized patient's hospitalization if he or she complains of pain in the back or neck; if weakness, numbness, or loss of control of extremities or sphincters develops; or if only screening radiographs were obtained during the admission evaluation.
Initial Care
Proper care of the potentially unstable spine begins at the scene of injury and continues until the spine has been proved stable. Adequate help is essential. Gentle manual traction stabilizes the head, which can be turned to the midline if necessary to protect the airway and to correct gross deformity. The neck should be placed and maintained in a position of minimal extension and taped to a padded spine board or similar support during transportation. The lower spine is protected by taping the patient to the backboard above and below major joints. Sandbags on each side of the head in addition to a cervical collar provide additional stability when the patient is transported from one location to another. The forehead should be taped to the backboard.
The history should include information determining the mechanism and forces of injury, and the site and duration of any pain. Transient or persistent numbness, tingling, and weakness or other neurologic problems must be noted, as should any prior injuries or other difficulties involving the spine or spinal cord.
Physical examination should include notation of abrasions or contusions anywhere on the head or trunk. They provide clues to the mechanism of injury. Spinal deformity can occasionally be seen, but palpation of the spine processes is frequently more rewarding.
The patient should be log rolled, and the dorsal spine palpated and checked for localized

21 tenderness, swelling, rotational deformity, or the presence of a gap between the spinous processes (indicative of a rupture of the posterior ligaments with resultant instability).
If a neurologic deficit is present, the examination focuses on defining the neurologic level of injury and on determining whether or not there is sparing of some spinal cord function across this level. The patient with incomplete spinal cord injury has motor or sensory function below the injury level. Sacral sparing may be the only evidence that paralysis may not be complete. Therefore, sensation in the perineum, voluntary sphincter contraction, and toe flexion must be carefully examined. Most incomplete spinal cord injuries exhibit mixed motor and sensory sparing rather than a classic pattern of partial injury. The natural history of incomplete cord injuries is to improve.
Well-documented evidence of deterioration is rare. If deterioration is observed, emergency diagnostic and surgical treatment is warranted. A complete spinal cord– injured patient has no distal motor or sensory function. It is essential that neurologic function be accurately recorded in the prehospital and emergency department notes to allow for later comparison. Unlike traumatic brain injury, steroids have been shown to play an important role in improving outcome in patients with complete or incomplete spinal cord injury. Methylprednisolone should be administered as an intravenous bolus of 30 mg. per kg., followed by a continuous infusion of 5.4 mg./kg./hr. for the next 23 hours, based on a double-blind, randomized, placebo-controlled multicenter study. 13
A spinal cord injury is followed immediately by a transient period of disordered function, called spinal shock. During this time, no reflex or voluntary activity can be elicited distal to the level of the injury. When some reflex activity has returned, the spinal cord lesion can be deemed complete if there is no distal sensation or voluntary motor control.
The normal sacral reflexes are the earliest to recover from spinal shock, usually within the first 24 hours. One such reflex is the bulbocavernosus reflex, contraction of the anal sphincter produced by compression of the glans or clitoris or by tugging gently on the
Foley catheter. The other is the anal wink, or contraction of the anal sphincter in response to a pinprick adjacent to it. By following these reflexes during the early stages of spinal cord injury, valuable prognostic information can be obtained.

22
Good-quality roentgenograms are as essential as the history and physical examination in the thorough evaluation of the patient with spinal injury. Radiologic examination of the cervical spine must be accomplished before moving the neck of all blunt trauma patients, particularly those who are unconscious, obtunded, or complaining of neck pain. The initial screening view is a cross-table lateral of the supine patient, taken with the film just lateral to one shoulder, with both shoulders actively or passively depressed so the entire cervical spine is visualized from the occiput to the top of T1.
The head is stabilized during this maneuver and not actively distracted away from the body, which can be disastrous in a severe C1–C2 ligamentous injury. Formal AP, lateral, and odontoid views should be obtained before the cervical spine is cleared, but flexion and extension radiograms are rarely indicated and are performed only if the preliminary films have shown no signs of instability and the patient is conscious and cooperative. The signs of impending spinal cord damage may be subtle. A small bony avulsion or slight malalignment of vertebrae may be the only suggestion of gross ligamentous instability. The physician who is seeking only fractures may ignore subluxations and even dislocations.
New-generation CT scanners greatly facilitate the evaluation of spinal trauma. Sagittal reconstructions can provide excellent portrayals of alignment, without the risk of positioning often required by conventional tomography or flexion and extension films.
Retropulsion of bone fragments and occasionally of disc material can be demonstrated, clearly showing the amount of canal narrowing that results. Magnetic resonance imaging (MRI) can beautifully demonstrate detailed neuropathology, including disc herniation, ligamentous injuries, and spinal cord mass lesions. It often has a complementary diagnostic role to CT in spinal cord injuries.
Treatment of Specific Injuries
The injured spinal cord should be treated by prompt reduction of any dislocation or angular deformity that compromises the spinal canal. This can usually be achieved with traction
(Gardner-Wells tongs or cranial halo) and the appropriate positioning of the patient.
Frequent neurologic monitoring and radiographs are necessary to identify deterioration,

23 overdistraction, or loss of alignment during reduction and when increased distraction weight is applied. If closed means are not effective in restoring the spinal canal, or if an incomplete spinal cord lesion is deteriorating, emergency surgical treatment may be necessary. Experience with incomplete thoracic level paraplegia suggests that immediate or urgent posterior Harrington distraction instrumentation or anterior transthoracic decompression and fusion is preferable to posterior reduction or late anterior decompression, with improved neurologic function demonstrated in 90% of patients so treated.
Neck
Although the neck is a unique trauma organ, with multiple vital structures concentrated in a small anatomic area, it is generally unprotected by bone or dense muscular covering.
Whereas most significant neck injuries result from penetrating trauma, blunt neck trauma does occur and can be particularly difficult to manage because it often involves the airway, the first priority in trauma care. In addition, major blood vessel injury of the neck can result from cervical spine hyperextension, even in the absence of bony injury.
Although the frequency of neck trauma is small (5% to 10% of all injuries), the consequences of this type of injury are great. Fatality rates for penetrating neck trauma range from 1% to 2% for stab wounds, 5% to 12% for gunshot wounds, and up to 50% for rifle or shotgun blasts. It is estimated that one half of these deaths are preventable with appropriate early care. 61
The neck is classically divided into a number of anatomic triangles .
Two large triangles are important in discussing penetrating neck trauma. Penetrating wounds that enter through the sternocleidomastoid muscle or anterior triangle carry a high likelihood of significant vascular, airway, or esophageal injury. In contrast, wounds to the posterior triangle rarely involve the esophagus, airway, or major vascular structures, but, if directed inferiorly, intrathoracic injury can occur.
The anterior neck is further divided into three zones defined by horizontal planes. Zone I represents the base of the neck and thoracic outlet. Injuries here carry the highest mortality because of the risk of major vascular and intrathoracic injury. Zone II

24 represents the largest portion or midbody of the neck. Because of its relative size, Zone
II injuries are most common but carry the lowest mortality. Significant injury is generally apparent, and exposure of vital structures is readily accomplished. Zone III is the part of the neck above the angle of the mandible. The risk of injury to the distal carotid artery, salivary glands, and pharynx is greatest in this zone, and exposure can be particularly difficult.
The other major anatomic landmark in the neck is the platysma muscle. This thin, broad muscle lies just beneath the skin and covers the entire anterior triangle and anteroinferior aspect of the posterior triangle. Wounds that fail to penetrate the platysma are considered superficial and do not warrant extensive evaluation. Wounds that do penetrate the platysma mandate hospital admission and further evaluation.
Selective Versus Mandatory Exploration
There continues to be controversy regarding management of neck wounds that penetrate the platysma muscle. Two distinct schools of thought exist on this subject: one advocating mandatory surgical exploration of all such wounds and one favoring a more selective approach. Those favoring routine exploration justify their position by emphasizing the disastrous complications of missed injuries and the relative safety and short hospital course of a negative exploration. Authors favoring a more selective approach berate the high incidence of negative explorations and the fact that some injuries are missed in spite of a formal exploration. Merion and associates analyzed 27 series reported in the literature in which the clinical course of more than 4000 penetrating neck trauma patients was documented 80. Carducci and Dalsey re-examined these same series and determined that only 2.4% of initially observed patients required subsequent operation. 15 Both reviews emphasized the similar outcomes in these two approaches and argue that either approach can be justified.
Perhaps more significant than this controversy are the areas of uniform agreement. All patients with clinical signs of significant injury require prompt exploration. All other patients (clinically silent) with wounds that penetrate the platysma should at least be admitted to the hospital and observed. The disagreement is whether patients without

25 positive clinical findings should: (1) routinely undergo a surgical neck exploration; (2) undergo extensive diagnostic evaluation; or (3) simply be observed. The authors continue to recommend exploration of the majority of neck wounds that penetrate the platysma. More specifically, injuries to the base of the skull and thoracic outlet (Zones
III and I) require angiography prior to, and occasionally in lieu of, exploration. Injuries to the mid-neck (Zone II) are generally managed by exploration without prior invasive diagnostic studies. Transcervical gunshot injuries represent a special category of neck wounds, with a greater than 80% likelihood of injury to cervical structures; surgical exploration is warranted in nearly all cases.
Initial Management
Active airway management is critical in the patient with a serious neck wound and takes precedence over all other aspects of the evaluation and resuscitation. Emergency intubation is necessary if spontaneous respirations are inadequate, if blood or vomit obstructs the airway, or if progressive cervical swelling from hemorrhage threatens to occlude the airway. Procrastination converts a simple intubation into a difficult, bloody emergency tracheostomy. If the airway is not jeopardized, nasogastric and endotracheal intubation may be deferred to allow endoscopic evaluation of the larynx and hypopharynx. The remainder of the initial therapy follows the guidelines previously outlined, with particular attention directed toward excluding cervical spine injury, providing adequate ventilation, and evaluating neurologic status.
Following initial resuscitation, a complete physical examination is performed to detect associated injuries and to better define the extent of neck trauma. The clinical signs that mandate neck exploration should be searched for. All patients should have a chest radiograph to rule out thoracic trauma. Stable patients should have soft tissue neck films to look for retropharyngeal hematoma, tracheal narrowing or deviation, retained missile fragments and pathways, and subcutaneous or retropharyngeal air. Neck CT is particularly helpful in blunt trauma to evaluate laryngeal structures. Patients sustaining blunt neck trauma, with a neurologic examination inconsistent with findings on head
CT scan, should undergo four-vessel angiography. As previously mentioned, the need

26 for further diagnostic testing (angiography, panendoscopy, and esophagography) versus immediate operative neck exploration is controversial. The authors believe preoperative angiography is indicated in the hemodynamically stable patient with multiple wounds, or penetrating wounds to Zone III (because of the possible inaccessibility of internal carotid artery lesions) and Zone I (to identify injuries to the thoracic outlet vessels. Symptomatic isolated injuries to the mid-neck (Zone II) are generally explored without the aid of arteriography. Endoscopy is usually performed intraoperatively if pharyngeal or esophageal injury is suspected but cannot be found, and routinely if a nonoperative policy is selected. The sensitivity of endoscopy for esophageal injuries is reported to range from 29% to 83%. 135 The addition of esophagography increases the accuracy and should be considered a complimentary procedure.
Exploration should be performed in the operating room under general endotracheal anesthesia. A nasogastric tube is usually passed to ensure an empty stomach.
Preparation and draping of the patient prior to induction of anesthesia allows control of hemorrhage if the patient starts to gag at the time of placement of the endotracheal tube.
The chest is also auscultated before operation, and a chest x-ray examination is routinely performed. Wounds at the base of the neck (Zone I) may follow a downward path with pleural penetration. A pneumothorax may not develop until positive pressure ventilation is applied and may initially present as unexplained hypotension during anesthesia. The incision is planned to allow full exposure of the tract of the injury.
Proximal and distal control of the major vessels must also be considered in the length and position of the incision, and the patient is always prepared for a possible median sternotomy. An oblique incision along the anterior border of the sternocleidomastoid muscle usually provides access to the vessels and other important cervical structures. If bilateral exposure is required, a transverse collar incision may be preferable. The tract of the injury is followed to its depth, systematically examining each structure in or near the tract.