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Decreased
Chest Wall Compliance
Pathophysiology
- Continued
impairment in chest wall
compliance
- Increasing
work of breathing
- Further
impairment with anesthesia
from early excision
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The
impaired expansibility of the chest wall
caused by deep burns is improved but
certainly not eliminated by escharotomy. A
significant impairment in compliance will
persist as a result of the loss of
elasticity in burn tissue. In addition,
tissue edema itself, which will remain for
many days, impairs expansion and, in turn,
decreases functional residual capacity and
vital capacity. Work of breathing and energy
requirements will remain increased. This
process is particularly relevant for
operative procedures requiring general
anesthesia. The effect of impaired chest
wall compliance on hemodynamic function will
be accentuated with the use of an anesthetic
that results in any element of myocardial
depression, since the increased positive
mean airway pressure is already impairing
cardiac output. In addition, general
anesthesia invariably impairs diaphragmatic
activity, thereby further increasing the
amount of positive pressure required to
maintain a constant tidal volume. The
process resolves as edema is reabsorbed in a
partial thickness burn or as full-thickness
burn is removed.
Treatment
- Careful
fluid resuscitation
- Semi-erect
position
- Assure
adequacy of escharotomy
- Ventilator
support
- Early
excision of deep chest wall
burn
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Maintenance
of a semi-erect position will assist in
movement of edema away from the chest wall
to more dependent tissues. Continued careful
volume replacement will minimize further
edema formation. Mechanical ventilator
assistance with positive pressure may be
needed to help maintain functional residual
capacity and minimize atelectasis as well as
diminish oxygen demands during this period
of impaired energy stores. Early excision of
the full-thickness wound will improve chest
wall motion by removing both edema and
noncompliant tissue.
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the Image to Enlarge
Persistent
Chest Wall Edema
  
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