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can be made both by observing clinical signs as well as by assessment of bladder pressure transduced

through a Foley catheter. Pressures over 20 mm Hg are considered abnormal and pressures greater than

25 mm Hg with evidence of organ failure indicate the urgent need for intervention. Strategies to

intervene should begin with decreasing the rate of fluid administration. If the patient has full-thickness

burns on the abdomen or torso, escharotomies should be performed. The bed should be reclined and a

chemical paralytic can be given to relax the musculature. If elevated bladder pressures remain despite

these maneuvers, a decompressive laparotomy is often required. Some surgeons will attempt

decompression with a suprapubic peritoneal drainage catheter; however, the morbidity of these

procedures is significant in burn patients. Therefore, attempts should be made to minimize fluid

overload with early vigilant monitoring of fluid administration.

When patients are difficult to resuscitate, additional monitoring devices can be used including

monitors of cardiac output and cardiac index. Examples include esophageal Doppler, bedside echo as

well as transthoracic echo. Serial echo examinations after providing a fluid bolus allow monitoring of

cardiac filling, IVC variation, and wall motion changes.53,54

Tetanus Prophylaxis

Burns are considered tetanus-prone wounds and therefore tetanus status should be obtained upon

presentation. Previous immunization within 5 years requires no treatment whereas immunization within

10 years requires a tetanus toxoid booster and unknown immunization requires both.

Escharotomies

Thoracic escharotomy is rarely required, however, if a patient has early respiratory distress, this may be

due to compromised ventilation caused by chest wall inelasticity. If chest wall compliance is limited due

to eschar, thoracic escharotomies should be performed bilaterally in the anterior axillary lines with

additional release under the costal margin. Extremity eschartomy can be limb or digit saving. Edema of

the underlying tissue under the thick, stiff eschar can produce vascular compromise. Though Doppler

and pulse oximeters can be used to follow perfusion, once perfusion is lost, it is often too late to

intervene. Thus, patients with circumferential full thickness extremity burns should have an

escharotomy as soon as their airway is stable and vascular access has been obtained. Extremity

eschartomy should be carried out medially and laterally and should extend the entire area of the full

thickness burns. Additional compartments to assess include the orbital compartment. Opthomology

should be consulted in large volume fluid resuscitation to assess intra-ocular pressure. If abnormally

elevated, a lateral canthotomy should be performed.

BURN SEVERITY

For full-thickness burns and partial-thickness burns, identifying the extent of the burn injury is crucial.

TBSA is useful to guide fluid resuscitation administration and defines the overall prognosis of patients.

Only partial- and full-thickness burns are totaled to calculate TBSA.

Figure 12-2. Rule of 9s used to estimate percent burns in adults (A), children (B), and infants (C). (From Stedman’s Medical

Dictionary for the Health Professions and Nursing, Illustrated, 6e. Philadelphia, PA: Lippincott Williams & Wilkins; 2008.)

If small areas in various distributions are affected, it may be easier to use the patient as a ruler with

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one palm size (patient’s) representing 1% TBSA. Another useful guide is the rule of 9s, where the adult

body is partitioned into several areas that each constitutes 9% of the TBSA (Fig. 12-2). Regions on the

adult that constitutes 9% of the TBSA include the head and arms, while the legs, anterior trunk, and

posterior trunk account for 18% of TBSA each. In children and infants, the body surface area of the

lower extremities constitutes a lower percentage while the head is higher. Careful estimation of TBSA is

essential for proper early management of burn patients, as patients who have burns of more than 20%

TBSA commonly require IV fluid resuscitation.

Acute burn injuries require prompt intervention and serial examinations. On initial evaluation, it is

important to recognize and treat constrictive circumferential burns that can lead to tissue ischemia and

subsequent necrosis by limiting perfusion to the distal tissues.46 The overarching concept, however, in

acute burn care is early debridement and grafting. All blisters and nonviable tissue must be debrided

upon presentation. After the initial debridement, dressing changes are initiated while the patient is

stabilized from a systemic standpoint. If patients suffer from full-thickness or deep partial-thickness

injuries, debridement and grafting within 72 hours should be the standard of care.

First degree or epidermal burns. These burns only involve the epidermis and therefore do not blister.

They do, however, have erythema and can cause pain. These burns will often desquamate by days 4 to

5.

Superficial partial thickness (second degree). Superficial partial thickness burns include the upper

layers of the dermis and usually form blisters at the interface of the epidermis and dermis. When the

blisters are removed, the wound is pink and wet and often is the site if significant pain. The wound

should blanch with pressure and the hair follicles should be visible. Assuming no infection sets in, these

burns should heal on their own in 3 to 4 weeks. They can be treated with xenograft to decrease pain.

Deep partial thickness (second degree). Deep partial thickness burns extend into the deep or reticular

dermis. These will also blister, but appear a “lobster” red. The patient often has some pain and there is

slow to absent capillary refill with applied pressure. The wound is often dry and if hair is present, it is

usually easily depilated. These burns usually require debridement and grafting.

Full thickness (third degree). Full thickness burns involve all layers of the dermis. These burns appear

white, insensate, and without capillary refill. The skin may appear depressed and leathery compared to

surrounding tissues. These burns require debridement and grafting as nondebrided eschar forms a nidus

for infection and inflammation.

Fourth degree. Fourth degree is used to describe burn into the deeper subcutaneous structures such as

muscle, fat, fascia, and bone. These are common in electrical burns and patients who were either

unconscious or insensate.

CRITICAL CARE OF THE BURN PATIENT

Hemodynamic Monitoring

Ideally, a critical care physician would be able to assess real time responses to fluid administration

through accurate cardiac output readings. Unfortunately, no such noninvasive devices to directly assess

cardiac output exist and those invasive devices that estimate cardiac output lack definitive studies

supporting their use. Some centers use a PiCCO device which provides cardiac output based on

temperature changes and use of the Fick equation, however, this requires a femoral arterial line and a

large bore IJ or SVC catheter which introduce potential for complications. Some surgeons use pulse

volume variation (>25% being abnormal), however, this too lacks accuracy. Though goal-directed

therapies with a pulmonary artery catheter, esophageal Doppler, transesophageal echo, or CVP monitor

have demonstrated promising results in some critical care populations, their use in burn patients has

been mixed.55,56 Frequently, the output of monitors such as pulmonary artery catheters or CVP monitors

fails to reflect the actual resuscitation of the patient.57,58

Ventilator Strategies

Treatment for Inhalational Injury

Manifestations of inhalation injury include wheezing and air hunger. Within a few hours, the

tracheobronchial epilthelium slughs and hemorrhagic tracheobronchitis develops. In cases with thermal

injury interstitial edema can cause acute respiratory distress syndrome (ARDS) and oxygenation

difficulty. If inhalation injury is suspected, the patient should undergo urgent airway assessment and be

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placed on supplemental oxygen. Inhalation injury has three components that must be considered: (1)

upper airway thermal injury which can cause swelling and obstruction, (2) CO poisoning, and (3) lower

airway chemical injury from toxic agents found in smoke. Upper airway thermal injury is treated by

intubation of the airway and CO poisoning is treated by 100% oxygen administration. Lower airway

injury is diagnosed by evidence of soot or mucosal irritation on bronchoscopy. Airway mucosal injury

from chemical pneumonitis leads to increased secretions while compromising the patient’s ability to

clear those secretions. This leads to increased risk of mucous plugging. Airway mucosal sloughing can

also result in bleeding and clot formation that further obstruct airways. The use of aerosolized heparin,

albuterol, and Mucomyst (HAM) following smoke inhalation to promote airway clearance is advocated

in some centers, however, larger studies are needed to validate these treatments.53,54,59–61

Early endotracheal intubation and mechanical ventilator support are important in patients with

inhalation injury or in large TBSA burns expected to receive large volume resuscitation. Ventilator

management should follow ARDSnet protocol recommendations.62,63 Low volume protective lung

ventilation is used to avoid barotrauma: 4 to 6 mL/kg tidal volume, peak airway pressures should not

exceed 30 cm H2O. Assess best positive end expiratory pressure (PEEP) to determine an optimal setting,

but a PEEP of at least 5 should be used to avoid lung derecruitment. Consider esophageal monitor to aid

in settings if the patient is obese. Recruitment maneuvers may be needed to improve oxygenation

and/or ventilation. Permissive hypercapnia is preferred over large tidal volumes to avoid lung

barotrauma. Limited studies have shown a potential role for high-frequency percussive ventilation in

burn patients.64 Elevating the head of bed to 45 degrees helps decrease airway swelling, prevents

aspiration and ventilator-associated pneumonia (VAP) for ventilated patients. Daily mouth care with

chlorhexidine should be used for ventilated patients.

Pulmonary infection occurs in 30% to 50% of patients. Patients with three of the following five

clinical criteria should be assessed for pneumonia with culture samples and placed on empiric antibiotic

therapy; purulent sputum production, fever, elevated white blood cell count, infiltrate on chest

radiograph, and increasing supplemental oxygen requirements. If the patient has pneumonia and been in

the hospital for over 48 hours, he should be treated for hospital-acquired pneumonia. Sputum or a

bronchoalveolar lavage samples should be sent for aerobic, anaerobic, and quantitative cultures.

Empiric antibiotics including coverage of Pseudomonas sp. should be started until culture results

become available. Empiric treatment should also cover methicillin resistant staphylococcus aureus and

thus vancomycin or linezolid is preferred. If vancomycin is used, drug levels should be followed to

adjust dosage and avoid renal toxicity.

Ventilator-Associated Pneumonia

Staphylococcus aureus and Streptococcus are common causes of early VAP. Pseudomonas aeruginosa is

the most common cause of late VAP. The usual signs of pneumonia (fever, purulent sputum, or

leukocytosis) are not helpful in burn patients since almost all patients are febrile, tachypneic, and have

elevated white blood cell counts. The best diagnostic test is bronchoscopy-obtained bronchial alveolar

lavage sample with quantification of bacteria. Bacterial counts of >103 colony forming units (CFU) are

considered positive. ABA recommendations for length of VAP treatment are 8 days of antibiotic therapy

for antibiotic-sensitive organisms and 15 days of therapy for multidrug-resistant organisms.65

Consideration should be given to antifungal therapy (Diflucan) if the patient does not respond to

prolonged broad-spectrum antibiotics.

Electrolyte Abnormalities and Acute Renal Failure

The immediate effects of burn injury on kidney function are secondary to hypovolemia and circulating

inflammatory mediators. The diuresis phase occurs at 48 to 72 hours after “third space” fluid is

reabsorbed. Hyponatremia is often seen due to large volume resuscitation with hypotonic IV fluids and

will usually self-correct. Open burn wounds or the use of topical silver nitrate can also cause

hyponatremia. Renal hypoperfusion exacerbates hyponatremia by decreasing glomerular filtration.

Hypernatremia may also occur due to insensible and evaporative water losses. Hypophosphatemia can

result from dilution or refeeding syndrome. Hypocalcemia can result from use of silver nitrate.

Acute Kidney Injury

4 Risk factors include sepsis, large TBSA burns, organ failure, and antibiotic administration. Renal

function is compromised by hypoperfusion, pharmacologic nephrotoxic insult, and sepsis which are all

common following major burn injury. Physiologically there is a decrease in renal perfusion, glomerular

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