Page 668 - ACCCN's Critical Care Nursing

Trauma Management 645

BOX 23.1 Criteria for treatment in a TABLE 23.11 Systemic changes that occur with
specialised burn centre 77 burn injuries 71

l Burns greater than 10% of total body surface area (TBSA) System affected Pathophysiological change
l Burns to special areas: face, hands, feet, genitalia, perineum,
major joints Cardiovascular system l Increased capillary permeability
leading to capillary leak of
l Full-thickness burns greater than 5% of TBSA intravascular proteins and fluids to
l Electrical burns interstitial compartment
l Chemical burns l Peripheral and splanchnic
vasoconstriction
l Burns with an associated inhalation injury l Reduced myocardial contractility
l Circumferential burns of the limbs or chest l Systemic hypovolaemia due to
l Burns in the very young or very old above, plus fluid loss from burn
l Burns in people with preexisting medical disorders that Respiratory system l Bronchoconstriction
could complicate management, prolong recovery or l Adult respiratory distress syndrome
increase mortality
l Burns with associated trauma Metabolic system l Increased basal metabolic rate (up to
3 times normal)
l The possibility of non-accidental injury in children l Above, plus splanchnic
vasoconstriction, will lead to
catabolism if patient not fed early
and aggressively

Zone of Zone of Immunological system l Downregulation of immune response
coagulation stasis
Zone of
Epidermis hyperaemia
Dermis contribute to this stasis include microthrombus for-
mation, neutrophil adherence, fibrin deposition and
endothelial swelling. Tissue in this zone is potentially
Adequate Zone of Inadequate salvageable if sufficient resuscitation is achieved to
resuscitation coagulation resuscitation increase tissue perfusion. If insufficient resuscitation
occurs, or if there are additional insults of hypoten-
sion, infection or oedema, tissue within this zone may
convert to the zone of coagulation.
l Zone of hyperaemia: the outermost zone. It experi-
ences increased tissue perfusion as a result of local
Zone of stasis preserved Zone of stasis lost inflammatory response, which results in local vasodi-
lation and an increase in vascular permeability. Tissue
FIGURE 23.6 Zones of burn damage.
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in this zone will usually recover, unless there are pro-
longed or severe periods of hypotension, infection or
oedema.
although thinner in the elderly and the very young. It is
composed of an outer papillary dermis and an inner Systemic changes
reticular dermis, and supplies nutrients to the epidermis. With a burn injury of >30% total burn surface area (TBSA)
The dermis contains all the accessory structures including microcirculation vessel wall integrity is altered resulting
blood vessels, nerve endings, the sweat and sebaceous in fluid and protein loss into the interstitium. The protein
glands and the hair follicles. The dermis itself does not loss results in a reduction in osmotic pressure which
have regenerative ability, but because the glands, vessels further insults circulating volume. Table 23.11 contains a
and follicles are lined with epidermis, burns that involve description of the changes to the cardiovascular, respira-
this layer may still regenerate. The innermost layer, the tory, metabolic and immunological systems that occur as
subcutaneous tissue, consists of adipose and connective a result of the release of cytokines and other inflamma-
tissue. This layer has no regenerative ability. tory mediators in response to the injury.
Local changes Inhalation injury
Local changes include the zones of coagulation, stasis and
hyperaemia (see Figure 23.6) and the specific changes are The presence of an inhalation injury will increase mortal-
71,72
outlined below. 71 ity and morbidity in people with a dermal burn injury.
Inhalation injury consists of three components that may
l Zone of coagulation: occurs at the point of maximum occur independently but often occur simultaneously, and
damage. Irreversible tissue loss occurs in this zone due include heat injury to the upper airways, effects of smoke
71
to coagulation of the constituent proteins. on the respiratory system and inhalation of toxic gases.
l Zone of stasis: surrounds the zone of coagulation and Diagnosis of an inhalation burn injury remains problem-
is an area of decreased tissue perfusion. Changes that atic, but it should be suspected if the injury was sustained