Blunt Thoracic Trauma
for those of us who deal with blunt trauma on a daily basis, a
report from the field that a high speed collision has occurred
with a victim who has sustained a "steering wheel injury"
raises our overall level of concern. The management of
thoracic trauma, with its attendant potential for life
threatening injury, if approached from the standpoint of
providing an airway, assuring adequate ventilation and
controlling hemodynamics falls within the realm of all
evaluating the airway in a patient with blunt thoracic trauma,
one must look for associated injuries to the head, face,
cervical spine and injuries to the upper and lower airway. Low
level of consciousness, airway obstruction or disruption, and
inability to oxygenate the patient by mask indicate the need
for tracheal intubation. Blood in the airway, recent food
intake, and trauma itself with decreased gastric emptying,
mandate an approach which minimizes the potential for
aspiration of gastric contents. Awake techniques with direct
visualization, i.e. fiberoptic or direct laryngoscopy, or
rapid sequence induction with cervical immobilization may be
appropriate depending on the clinical scenario and level of
skill of the anesthesiologist.
careful physical assessment of the ventilatory function of the
thoracic trauma victim should include inspection for
respiratory rate, presence of paradoxical motion of the chest
wall, or obvious chest wounds. Palpation of the chest should
seek pain, crepitus or subcutaneous emphysema as clues to
underlying pathology. The auscultation of the lung fields may
detect a pneumothorax or hemothorax before a chest xray may be
performed, as well as assessing the adequacy of air entry.
Percussion although theoretically of use in differentiating
between pneumo and hemothorax may be practically difficult in
the atmosphere surrounding a typical resuscitation bay.
Since hypotension in thoracic trauma is
usually associated with hypovolemia it should be aggressively
treated initially with volume expansion with crystalloids
while other possible etiologies, i.e. pneumothorax, cardiac
tamponade and blunt cardiac injury are assessed. The presence
of arrhythmia should raise suspicion of blunt cardiac injury.[2,
3]. Hypertension may dramatically worsen bleeding in thoracic
trauma and may dislodge thrombus which is containing a major
vessel disruption and therefore should be treated. Two large
bore peripheral IV's are a minimum for resuscitation and a
central access is usually needed both for therapy and
usual laboratory tests, complete blood count, electrolytes,
glucose, BUN, creatinine, urinalysis, ECG, and blood type and
crossmatch should be obtained.
chest xray is of paramount importance in thoracic trauma and
only attention to life threatening problems should delay
obtaining it.. Systematic review of the radiograph may
reveal both suspected and unsuspected pathology. The bony
thorax including ribs, clavicles, scapulae, and vertebrae,
should be examined for fracture. Soft tissues should be
evaluated for emphysema or opacification. The lung fields may
likewise demonstrate pneumothorax, hemothorax, consolidation
suggestive of lung contusion. Radiographic abnormalities of
the mediastinum, particularly pneumomediastinum, widening of
the mediastinum, or shift of the mediastinum suggest airway
rupture, aortic disruption, and tension pneumothorax
respectively. Finally assessment of the cardiac silhouette may
aid in the diagnosis of blunt myocardial injury including
addition to the lateral cervical spine and pelvis films which
are generally obtained for every blunt trauma victim, several
imaging examinations are of particular interest in the work up
of thoracic trauma. The echocardiogram, either precordial or
transesophageal, is useful in evaluating for pericardial fluid,
valve and wall motion, and the presence and extent of aortic
disruption. Computerized tomography of the chest may reveal
aortic disruption and pneumothorax not readily apparent on
plain chest xray. Finally, arteriography is used to precisely
locate vascular injury.[4, 5]
fractures should be taken in context. Their presense indicate
a need for examining the underlying lung for contusion,
laceration, hemo or pneumothorax. Multiple or anterior and
posterior rib fractures may cause a flail segment. Fracture of
the relatively protected first through third ribs indicates
severe impact and mandates careful search for associated
contusion frequently manefests itself as hypoxemia. the goals
for treatment are oxygentherapy, positive pressure either with
a CPAP mask or by intubation and mechanical ventilation with
PEEP. Splinting from the pain associated with rib fractures
requires adequate pain management, i.e.parenteral narcotics,
interpleural local anesthetics, or epidural narcotics/local
anesthetics. The contused lung is prone to capillary leak and
therefore careful fluid management is indicated.
high index of suspicion for the presence of a pneumothorax
must be maintained in all blunt trauma victims. Auscultation
may be difficult in the ER. Other signs of tension
pneumothorax, tracheal deviation, hypotension, hypoxemia
should trigger chest decompression prior to CXR. If the
patient is stable an xray may preceed the thoracostomy.
Patients with multiple rib fractures may harbor a subclinical
pneumothrax and may require "prophylactic"
thoracostomy prior to OR.
to 40% of the blood volume can be accomodated in one
hemothorax. 1500 ml of initial blood output in chest tube
drainage is an indication for thoracotomy as a large vessle or
cardiac rupture may be present. Bronchial injury Blunt
injury to the lower airways is usually caused by deceleration
or compression injury. These injuries typically present as
either a pneumothorax which doesn't resolve or a persistent
air leak with tube thoracostomy. While rare, (0.4% of 515
patients in one study) tracheal or bronchial injury poses
management issues for the anestheiologist. Fiberoptic
evaluation of the airway may serve as a guide for intubation
as well as aid in the location of injury for surgical
correction. Lung isolation procedures are frequently employed
widened mediastinum on chest xray in the blunt trauma victim
is usually associated with aortic injury. Several technical
factors of the AP portable films taken in the emergency
setting, i.e. supine position, expiratory film, and the
magnification effect of a short beam distance, may make the
mediastinum appear widened. Loss of the aortic knob contour,
shift of the esophagus (nasogastric tube) to the right and an
apical cap in addition to mediastinal widening indicate need
for further workup.[4, 5]
of patients with thoracic aortic rupture die in the
pre-hospital setting. Those who survive to to reach the
hospital may have minimal symptoms. The chest film may give
the first suggestion of injury. The rupture is usually at the
isthmus just distal to the left subclavian artery. Control of
blood pressure is critical to avoid further dissection.
Emergent surgery with poor hemodynamic stabilization has high
to Thoracic Aortic Tear
Monitors: Routine plus invasive right sided aline, femoral
aline, large bore CVP, pulmonary cath, TEE
Large bore intravenous lines with fluid warmers
Induction strategy which minimizes hemodynamic changes.
Double lumen tube for lung isolation
Control of proximal hypertension during crossclamp
vasodilators/beta blockers limit intravenous fluids
Control of hypotension after release of clamp with fluid
loading and tapering of vasodilator.
Strategies for renal/spinal preservation: short crossclamp,
shunt, atriofemoral bypass, femoral vein-femoral artery
Pain control epidural? [5, 9, 10]
Blunt Cardiac Injury
trauma to the heart covers the spectrum of myocardial
concussion,contusion to myocardial rupture. The right atrium
and ventricle are the most frequently injured chambers because
of their anterior positioning in the chest, followed by left
atrium and left ventricle. Survival from one chamber rupture
is about 40% . Two chamber rupture has uniform mortality. Once
again echocardiaography is extremely useful in the diagnosis
of this injury.
with suspected myocardial contusion are no longer routinely
subjected to prolonged observation in a monitored setting. If
the ECG and echocardiogram are normal the patient may go home
after 12 hours if no other injuries are present. Young
patients rarely have cardiac related complications even when
cardiac contusion is diagnosed. The best test for diagnosis
remains controversial. The ECG is unreliable unless ST
elevation is present. CPK MB isoenzymes may be nondiagnostic.
Cardiac troponin I which may be more specific for myocardial
damge has not been adequately evaluated. Echocardiography is
useful for detecting wall motion abnormalities, pericardial
effusions and in combination with abnormal CPK MB may predict
complications. Radionuclide angiography may also be predictive
of complication. Thallium scanning can detect areas of
decreased perfusion, but cannot differentiate an acute from
preexisting lesion[3, 12]
tamponade should be suspected when there is hypotension
unexplained by other findings ie tension pneumothorax,
hemothorax, abdominal or other hemorrage. Neck vein distention
may be masked by the cervical collar. Echocardigraphy is
probasbly the best diagnostic tool. If a PA catheter is
present equalization of pressures may be seen. Prompt drianage
via pericardial window is the best treatment. This procedure
may be performed with local anesthesia. Hemodynamic changes
are minimized with the spontaneously breathing patient.
Underlying injury may be ruptured heart, aortic disruption, or
myocardial contusion without rupture.[1, 6, 11]
of diaphragmatic rupture are similar to pneumothrax
as the lung is compressed and hypoxemia developes. Diagnosis
is made with the chest xray. Loss of the diaphragmatic
countour, presense of bowel or NG tube in the chest or
elevaton of the right hemidiapragm are all suggestive.
Intubation and mechanical ventilation are needed for adequate
oxygenation. Hemothorax may be from a ruptured spleen.[1, 4]
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