Page 91 - JSOM Summer 2022

obstruction and respiratory arrest. Inhalation injury–induced Guard (Combat Medical, https://combatmedical.com/). If an
airway obstruction is primarily manifested by dyspnea, hoarse- active-heating element is used in conjunction with these heat
ness, and stridor, with low oxygen saturation signaling signifi- shells, it is critical that it not be placed directly in contact with
cant progression of the obstruction. Aggressive monitoring of the skin. Partial thickness burns have resulted from this error. 38
these signs, in conjunction with monitoring of oxygen satura-
tion (SpO ) and end-tidal carbon dioxide (EtCO ) if available, Appropriately treating a burn patient’s pain level is para-
2
2
allows for rapid placement of a definitive (subglottic) airway mount, as good pain control is associated with better wound
prior to complete obstruction. Except in extreme circum- healing, sleep, and recovery. Recent literature has highlighted
stances, analgesia and sedation must be administered before that analgesics are routinely not administered, or are not ad-
18
performing this intervention. ministered in high enough doses to burn patients. For the
prehospital provider, ketamine is an excellent analgesic agent.
Fluid Resuscitation For moderate to severe pain, ketamine can be administered at
For burns greater than 20% TBSA, parenteral fluid resuscita- 0.3mg/kg IV/IO or 0.5–1mg/kg IM/IO, repeated every 5–10
7
tion is indicated to treat hypovolemic burn shock. A balanced minutes as needed. To induce general anesthesia, the dose is
39
crystalloid solution such as lactated Ringer’s (LR) is preferred. 1–2mg/kg/hr IV/IO. Typically, ketamine supports the blood
40
In a tactical setting, the US Army Institute of Surgical Research pressure, but patients in shock may develop hypotension in
(USAISR) Rule of Ten is used to calculate the initial fluid in- response to the full anesthetic dose, so the provider should
fusion rate. For adults weighing between 40–80 kg, this rate be prepared to support the blood pressure with vasoactive
30
is calculated by multiplying the TBSA × 10mL/hr. For patients medications. As ketamine is a dissociative anesthetic, airway
weighing greater than 80 kg, an additional 100mL/hr should reflexes and spontaneous breathing are usually maintained,
be added for every 10 kg above 80 kg. For example, a 90-kg but some patients develop excessive salivation or, rarely, la-
patient with 30% TBSA burns would receive 400mL/hr (30% ryngospasm. Nystagmus is a common side effect during use.
TBSA × 10mL/hr + 100mL/hr). This formula is for adults only; Agitated emergence reactions are possible in adult patients.
for children, a weight-based formula such as the modified
Brooke formula for children must be used. Escharotomy
In a PFC setting, performing a surgical escharotomy may be a
Edema and “Fluid Creep” Considerations necessary life- or limb-saving treatment (Figure 1). However,
Burn care as a field has moved toward recognizing “fluid it should only be performed by personnel who are specifically
creep,” or over-resuscitation, which has been linked to exces- trained and qualified to do so. It is indicated in burn patients
sive edema and organ failure. 31,32 Over-estimation of burn size who are experiencing circulatory or respiratory compromise
is common, and can lead to excessive fluid resuscitation. An- due to circumferential full-thickness burns. For example, a
other common error is failure to titrate the fluids attentively patient with full-thickness burns of the chest may experience
after fluid resuscitation has begun. 18,33 The “fluid creep” con- respiratory distress due to the lungs being unable to fully in-
cept suggests that an excessive amount of fluid up front exac- flate against the rigid chest wall. A thoracic escharotomy will
erbates the edema process without any lasting beneficial effect provide the chest wall enough freedom of movement to fully
on expanding the plasma volume. Thus, resuscitation becomes expand with inspiration.
dysregulated or “runaway,” causing further edema formation
as time progresses. 30,34 This underscores the importance of
(1) estimating burn size carefully; (2) calculating the initial
fluid infusion rate accurately; and (3) titrating the infusion
rate on an hourly basis using physiologic endpoints. The pri- FIGURE 1 Visual
mary indicator of resuscitation adequacy is the urinary out- representation of
put; the fluid input should be adjusted hourly, up or down, to escharotomy locations.
achieve a urine output of 30–50mL/hr in adults (0.5–1.0mL/ Reprinted from Emer-
kg in children). There has been a recent increased use of col- gency War Surgery, 5th
loids versus crystalloids in fluid resuscitation. Despite this, the US Revision. 65
use of colloids is still controversial. Recent calls for the use
35
of plasma have underscored the benefit of its endothelium sta-
bilization properties. 36
Temperature and Pain Considerations In the case of circumferentially burned extremities, loss of dis-
Once intravenous (IV)/ intraosseous (IO) access has been ob- tal pulses (e.g., radial and ulnar at the wrist, or dorsalis pedis
tained and the patient is receiving fluid at the appropriate rate, and posterior tibial at the ankle) is an indication for extremity
assessing for and treating hypothermia is indicated. The pro- escharotomy. When performing an escharotomy, it is critical
vider should closely monitor the patient’s core temperature to that the depth of the incision is deep enough to go through the
18
prevent hypothermia and subsequent complications. Recent full thickness of the eschar and into the subcutaneous tissue,
research argues for appropriate temperature management but not into the investing fascia of the muscles. Sterile tech-
of the burn patient before definitive care, especially for pa- nique should be used, whenever possible. Afterwards, hemo-
tients experiencing a larger percent TBSA burn, who may be stasis should be assured, and the wounds dressed with topical
at higher risk for complications and mortality. This includes antimicrobials as discussed below.
37
wrapping all burns with dry sterile dressings and placing the
patient in a heat-reflective shell such as the North American Burn-Wound Treatment
Rescue Hypothermia Prevention and Management Kit (North Burn wounds are rapidly colonized with a number of different
American Rescue, https://www.narescue.com/) or APLS Life microorganisms. Before the development of effective topical

Pathophysiology and Treatment of Burns | 89