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| Chest
Trauma
Haemothorax
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.
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!
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Multiple stabbing: front |
Don't forget 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 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 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. The significance of small haemothoraces
that are not visible on plain films is not entirely clear.
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FAST
Right Upper Quadrant
Examination
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Haemothorax,
diaphragm & liver
(Left to Right) |
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.
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| Trachea |
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| Expansion |
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| Percussion Note |
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| Breath sounds |
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Haemothorax: Erect
Haemothorax: Erect
Right Haemothorax (supine)
CT Haemothorax (massive)
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Management
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 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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Chest Drain
Subsequent thoracotomy
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| Complications
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 mini-thoracotomy. 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.
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References
Diagnosis
Feliciano DV, Rozycki GS. 'Advances
in the diagnosis and treatment of thoracic trauma.'
Surg Clin North Am. 1999;79:1417-29
Rozycki GS, Feliciano DV, Davis TP 'Ultrasound
as used in thoracoabdominal trauma.' Surg Clin
North Am. 1998;78:295-310
Abboud PA, Kendall J. 'Emergency
department ultrasound for hemothorax after blunt traumatic
injury.' J Emerg Med. 2003;25:181-4
Ma OJ, Mateer JR. 'Trauma ultrasound
examination versus chest radiography in the detection
of hemothorax.' Ann Emerg Med. 1997;29:312-5
Parry GW, Morgan WE, Salama FD. 'Management
of haemothorax.' Ann R Coll Surg Engl 1996;78:325-326
Retained Haemothorax
Meyer DM, Jessen ME, Wait MA, Estrera
AS. 'Early evacuation of traumatic retained hemothoraces
using thoracoscopy: a prospective, randomized trial.'
Ann Thorac Surg. 1997;64:1396-400
Vassiliu P, Velmahos GC, Toutouzas KG.
'Timing, safety, and efficacy of thoracoscopic
evacuation of undrained post-traumatic hemothorax.'
Am Surg. 2001;67:1165-9
Watkins JA, Spain DA, Richardson JD,
Polk HC Jr. 'Empyema and restrictive pleural processes
after blunt trauma: an under-recognized cause of respiratory
failure.' Am Surg. 2000;66:210-4
Velmahos GC, Demetriades D, Chan L et
al. 'Predicting the need for thoracoscopic evacuation
of residual traumatic hemothorax: chest radiograph is
insufficient.' J Trauma. 1999;46:65-70
Inci I, Ozcelik C, Ulku R. 'Intrapleural
fibrinolytic treatment of traumatic clotted hemothorax.'
Chest 1998;114:160-5 |
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trauma.org
9:2, February 2004
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