Chest Injuries—Rib Fractures
Rib fractures are the most common injury resulting from blunt
chest trauma. The fracture itself generally requires
no specific treatment and will heal spontaneously over a period of several weeks.
Therapy is directed at minimizing pulmonary complications secondary to these fractures,
such as pain, splinting, atelectasis, hypoxemia, and pneumonia. Of particular concern
are rib fractures in the elderly (older than 55 years). Elderly patients with rib
fractures have twice the mortality and thoracic morbidity of younger patients with
similar injuries. Epidural anesthesia should be liberally used in patients with
severe pain, the elderly, and patients with preexisting compromised pulmonary function.
Some data support a decrease in morbidity and mortality in the elderly by 6% when
epidural anesthesia is used.[206]
In addition to
and as a result of adequate pain control, epidural analgesia may minimize or avoid
complications of splinting and pain such as hypoxemia, hypoventilation, the need
for tracheal intubation, and the possibility of pneumonia. Endotracheal intubation
is reserved for patients who are unable to oxygenate or ventilate or who require
protection of the airway. The trauma anesthesiologist should be aware of the potential
for associated lung injuries such as pulmonary contusion, pulmonary laceration, or
hemopneumothorax and use modes of mechanical ventilation that minimize further lung
injury.
Fracture of multiple neighboring ribs will result in flail chest
syndrome, characterized by paradoxical chest wall motion during spontaneous ventilation.
Not all patients with a flail chest require ventilation and positive pressure for
internal chest stabilization, and endotracheal intubation should be reserved for
those who meet the usual criteria. Patients who are not initially intubated should
be closely observed in the ICU for signs of worsening respiratory function. Increasing
numbers of reports have described the use of noninvasive positive-pressure ventilation
(NIPPV) for lung injury caused by trauma.[207]
For patients who subsequently require intubation for a surgical procedure, the anesthesiologist
will need to determine the safety of extubation postoperatively. NIPPV is associated
with fewer cases of pneumonia, which may lead to fewer tracheostomies and therefore
decreased ICU length of stay. A successful technique has been early extubation to
a continuous positive airway pressure (CPAP) or biphasic positive airway pressure
(BiPAP) mask.[208]
Concomitant pulmonary injury,
especially lung contusion, is commonly associated with flail chest. Pulmonary contusion
will cause shunting, which will lead to hypoxemia. This syndrome may progress rapidly
in the hours and days after injury. An initially clear chest radiograph does not
exclude the possibility of a pulmonary contusion, and again, close observation is
warranted if signs of significant chest wall trauma are noted. As with all patients
after traumatic injury, a high degree of suspicion and a continuous search for missed
injuries are warranted. No specific treatment of pulmonary contusion is available,
and therapy is directed at the associated injuries or resultant hypoxemia. The natural
history of pulmonary contusion is variable; contusions may resolve without sequelae
or may lead to either pneumonia or ARDS. Early and aggressive implementation of
a lung-protective strategy is crucial in the treatment of patients with a significant
pulmonary contusion to minimize progression to ARDS or concomitant ventilator-associated
lung injury. Prevention of ventilator-associated injury should be a standard part
of the anesthetic management of all severely injured trauma patients intraoperatively,
regardless of whether direct injury to the lung was sustained from the trauma itself.
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