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Chapter 4. Initial Management andResuscitation
F . The Rule of
Nines can be used to
provide a quick initial
estimate of burn size.
Reproduced from
Emergency War
Surgery: Fifth United
States Edition. Fort Sam
Houston, TX: Borden
Institute, 2018
115
Airway: Who Needs tobeIntubated,
andHow?
It is well recognized that a patient with symptomatic inhalation
injury, to include respiratory distress, cough, hoarseness, or
stridor, should be expeditiously intubated. While it is true
that the patient with minimal signs and symptoms of inhala-
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L. C. Cancio and J. M. Cancio
tion injury can be safely monitored in a critical care setting,
prophylactic intubation before ambulance or aeromedical
transport is often prudent. Even patients without inhalation
injury, but whose burn size is 40% or greater, should be intubated simply because progressive edema during the first
24–48h places the airway at risk (and makes intubation more
difficult as time goes on). These patients may develop rapid
airway obstruction soon after injury, or more insidiously during the course of the first 24–48h postburn [4, 5].
Induction of general anesthesia in patients who are
hypovolemic because of burn shock may precipitate
hypotension. Ketamine is considered a good choice for
induction, because it generally maintains the blood pressure
by increasing sympathetic outflow from the central nervous
system. But even ketamine, which also has a myocardial
depressant effect, may cause hypotension in the maximally
“catecholamine- depleted” burn shock patient [6]. Thus, the
provider must be prepared to support the blood pressure
pharmacologically during intubation.
The endotracheal tube must be secured in a manner which
precludes dislodgement. Adhesive tape does not stick to the
burned or edematous face in burn patients and should not be
used. Rather, a umbilical tie (or similar technique) should be
used to secure the tube circumferentially around the head
and neck. Once placed, the endotracheal tube should be religiously suctioned as often as necessary, removing sloughed
cellular debris, fibrinous exudate, and mucus, thus maintaining and ensuring patency. If not, patients with inhalation
injury may experience complete tube obstruction and may
require emergency exchange [4].
It is reasonable to follow low-tidal-volume (ARDSNet)
recommendations in the mechanical ventilation of intubated
burn patients, with three caveats. First, patients with suspected inhalation injury should receive 100% oxygen until
carbon monoxide poisoning can be ruled out by means of
co-oximetry (direct measurement of the carboxyhemoglobin
level, or, alternatively, until 6h have passed) [7].
Chapter 4. Initial Management andResuscitation
F . Location of
escharotomy incisions.
The bold lines indicate
the importance of
including the eschar
overlying any involved
joints in the incisions.
Reproduced from
Emergency War
Surgery: Fifth United
States Edition. Fort
Sam Houston, TX:
Borden Institute, 2018
117
Second, patients with circumferential, deep burns of the
torso may develop a thoracic eschar syndrome. In these
patients, the tight inelastic eschar and the formation of edema
fluid beneath the eschar progressively impede chest excursion. These patients require emergency escharotomy of the
chest in order to permit respiration (Fig.4.2). Escharotomy is
performed expeditiously at the bedside. A Bovie electrocautery device is used to incise through the full thickness of the
skin and into the subcutaneous tissue. Successful chest escha-
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L. C. Cancio and J. M. Cancio
rotomy results in rapid restoration of chest excursion and a
decrease in peak airway pressures.
Third, we have shown the superiority of high-frequency
percussive ventilation (Volumetric Diffusive Respiration
[VDR], Percussionaire, Sandpoint, ID) to low-tidal volume
ventilation, particularly in inhalation injury patients—
reflecting the underlying pathophysiology of this patient
population [8].
Fluid Resuscitation: Why andHow?
After managing the airway, fluid resuscitation is the main
goal of therapy during the first 48h postburn. Patients with
burn size greater than 20% TBSA—and many patients with
burn size greater than 10% TBSA, such as children and the
elderly—require formal burn resuscitation. Burn shock features three elements:
• Hypovolemia caused by loss of fluid from the intravascular
space into the interstitial space in response to changes in
the Starling forces across the microvasculature (often sum-
marized as “leaky capillaries”) [9, 10]. In patients with
larger burns, this occurs in both burned and unburned tis-
sues [11].
• Increased systemic vascular resistance, reflecting massive
catecholamine release [12].
• Decreased myocardial contractility, which is more
commonly evident in older patients and in those with
medical comorbidities [13, 14].
Of these factors, the first one, hypovolemia, is the primary
target of most of our resuscitative efforts. Replacement of
ongoing plasma volume losses, in order to restore cardiac
output and maintain vital-organ perfusion, is the main goal of
resuscitation. But the time course of burn shock is more
gradual than that of hemorrhagic shock, and there is no intervention (analogous to surgery to repair a blood vessel) which
can rapidly repair the diffuse microvascular permeability of
Chapter 4. Initial Management andResuscitation
119
burn injury. Rather, the purpose of burn resuscitation is
gradually to replace ongoing plasma volume losses while
waiting for the body to recover its microvascular integrity.
Meanwhile, as fluids leak out of the vascular space into the
interstitium, they cause edema, both locally (in the burn
wound) and systemically. Careful titration of fluid input is
required in order to prevent excessive edema on the one
hand, and inadequate vital-organ perfusion on the other.
The most commonly used fluid for IV burn resuscitation is
lactated Ringer’s solution (LR). Other balanced crystalloid
solutions, such as Plasma-Lyte A, are also used. The use of
crystalloids instead of colloids is predicated on the concept
that increased microvascular permeability makes the use of
colloids ineffective during the early postburn hours [15]. The
exact time at which such permeability begins to be repaired
(making colloids more effective) is a matter of debate, may
range between 8 and 24h postburn, occurs sooner in unburned
tissues than in burned tissues, and is probably patient-specific
[11, 15]. 5% albumin is often used during the 2nd 24h postburn (hours 25–48), or earlier as a “rescue” strategy (see
below) [16–18]. Recently, there has been a renewed interest in
the use of plasma for resuscitation, not merely because of its
colloidal properties, but also with the intent of restoring the
endothelial glycocalyx [19].
Peripheral IV access (through unburned skin, through
burned skin if necessary) is adequate for initiation of burn
shock resuscitation. It is common practice to place a central
venous catheter (and an arterial catheter) under sterile conditions to permit multiple infusions and monitoring in
patients with larger burns. These lines must be securely
sutured in place to prevent dislodgement.
After IV access is obtained, a controlled infusion of LR
should be started at an age-based rate: 500 mL/h for adults,
250mL/h for children, 125mL/h for small children. This buys
time while the burn size is measured and one of the formulas
is calculated (see below). The temptation to give an initial
bolus (except for profound hypotension) should be avoided
[20]. During the hyperpermeable phase of early burn shock,
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L. C. Cancio and J. M. Cancio
the likely fate of a bolus is rapid loss into the interstitium and
increased edema formation, with no lasting benefit.
Given the need for careful fluid dosing in burn resuscitation,
a variety of formulas have been used to help estimate the
starting rate for IV infusion. The traditional burn shock
resuscitation formulas take into account the patient’s burn
size and weight. Thus, the modified Brooke formula estimates
that patients should receive 2mL/kg/TBSA burn of LR during the first 24h postburn [15], whereas the Parkland formula
estimates 4 mL/kg/TBSA burn [21]. Under the Brooke formula, for example, an 80-kg adult with a 40% burn would be
programmed to receive 2mL*80kg*40%=6400mL over the
first 24h postburn, with half of this, or 3200mL, scheduled for
infusion over the first 8 h postburn, and half over the next
16h postburn. Thus the starting rate under the Brooke formula would be 3200mL/8h or 400mL/h.
The Parkland formula would estimate twice as much:
4*80kg*40%=12,800mL over the first 24h, with half of this
given over the first 8h postburn, or 800mL/h. Particularly in
patients with large burn sizes, the amount of fluid predicted
by the Parkland formula can be massive and potentially hazardous (see Complications, below). Furthermore, many
patients, whether started on the Brooke or the Parkland formulas, experience an increase in the volume delivered in
excess of the formula predictions [22–24]. Accordingly, the
Advanced Burn Life Support (ABLS) course now recommends the Brooke formula, that is, 2mL/kg/TBSA burn [20].
Since there is a certain amount of math involved in the
above calculations, a simpler burn formula was introduced
called the “ISR Rule of Tens” for adults. The Rule of Tens
states that the initial fluid resuscitation rate is the burn size*10.
For example, an adult with burn size of 40% would be started
on resuscitation fluid at 40*10=400mL/h. An adult with a
burn size of 60% would be started at 60*10=600mL/h. This
formula usually gives predictions which are between those
of the Brooke and Parkland formulas. (In addition, patients
with weight over 80 kg receive an additional 100 mL/h for
each additional 10kg. Thus, a 100kg person with a 40% burn
Chapter 4. Initial Management andResuscitation
would receive 400mL/h+200mL/h= 600mL/h). The Rule
of Tens is the formula we now use at the US Army Burn
Center [25].
The Rule of Tens formula only applies to patients with
weight greater than 40kg; for smaller patients, a weight-based
formula must be used. Furthermore, children have a greater
surface-area-to-weight ratio. Thus, they are estimated to
require more than the Brooke formula, that is, 3mL/kg/TBSA
burn. Again, half of this is programmed for the first 8h [26].
In addition to receiving resuscitation fluid, smaller children
(< 30 kg) also need a maintenance fluid rate. This serves two
purposes. First, the amount of fluid predicted by the formulas
may be less than maintenance for small children with small
burns. Second, small children may deplete their glycogen
stores and become hypoglycemic during burn shock. To
prevent this, an exogenous glucose source is helpful. The
maintenance fluid of choice for children is D5LR or
D5½NS.The rate should be that calculated by the 4-2-1 rule
(4mL/kg for the first 10kg, 2mL/kg for the next 10kg, 1mL/
kg for the subsequent kilograms). Normally, this rate is not
adjusted during resuscitation—it runs in the background
while the resuscitation fluid is titrated according to physiologic response [20].
121
Monitoring
It is important to realize that all of these formulas only
provide a starting rate; there is no sudden change in the fluid
infusion rate at the eighth postburn hour in actual practice;
and the hourly infusion rate has to be titrated based on physiologic response. The patient must be continually reassessed
during the 24–48h postburn. The hourly urine output (UO)
is the primary index of the adequacy of fluid resuscitation.
Thus, a Foley catheter should be placed and the UO recorded
hourly for patients undergoing IV resuscitation. The target
UO for adults is 30–50 mL/h; for children it is 1.0 mL/kg/h
[20]. (An exception is the patient with gross myoglobinuria
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L. C. Cancio and J. M. Cancio
due to high-voltage electric injury. As described in the chapter on that topic, the target UO in these patients is 70–10 0mL/h
for adults.) Reducing the fluid infusion rate when the UO is
too high is just as important as increasing it when the UO is
too low [24]. As needed, an increase or decrease of about
25% every hour or two is a reasonable rule of thumb.
Nevertheless, the UO alone is often insufficient for
monitoring. The accuracy of the UO should be questioned in
patients with renal failure, diuretic use, or alcohol intoxication, and other indices of resuscitation should be considered.
Furthermore, in all patients with burn shock, the following
should be monitored as well:
• Heart rate. Because of increased sympathetic nervous
system (SNS) activity and catecholamine release, a
previously healthy person undergoing burn resuscitation
normally has an elevated heart rate (100–120/min in
adults). A further increase, even in the absence of
hypotension, suggests hypovolemia.
• Blood pressure. Again because of SNS and catecholamine
effects, hypotension is a late finding during burn shock
resuscitation. A normal blood pressure, per se, is not very
reassuring. The non-invasive blood pressure, particularly
on burned extremities, may be inaccurate, and an arterial
catheter is often placed when patients are undergoing IV
fluid resuscitation.
• Lactate. Burn shock patients typically develop a lactic
acidosis which resolves with successful resuscitation [27].
Lactate correlates with postburn mortality, but how best to
use it is ill-defined [28, 29]. Certainly, an increasing lactate
should prompt a reexamination of whether the patient’s
shock state is worsening.
• Arterial base deficit. Patients also typically develop a base
deficit, which also correlates with postburn mortality [30].
This does not exactly mirror the lactate and may represent
other consequences of shock such as renal tubular acidosis
secondary to acute kidney injury [28].
• Fluids (hourly fluid infusion rate [mL/h] and cumulative
fluid volume [mL/kg]). Awareness of these variables is
Chapter 4. Initial Management andResuscitation
123
extremely important during resuscitation, since the vol-
ume infused during the first 24h correlates with complica-
tions such as abdominal compartment syndrome that must
be avoided if at all possible (see below) [31].
• Vasoactive drug infusion rates (if any).
Finally, data from invasive cardiac output monitoring
devices may be useful. These methods include the pulmonary
artery (PA) catheter; those which estimate cardiac output
from analysis of the arterial blood pressure waveform; those
which perform transpulmonary indicator dilution; and echocardiography. The data from these devices must be interpreted with reference to the values expected at that point in
the resuscitation process. That is, burn shock is a dynamically
changing phenomenon. The successfully resuscitated burn
patient passes through 3 stages (Table4.1) [15].
One impact of this concept of “stages” is the following.
Early attempts to make intravascular volume and cardiac
output normal (or worse, supranormal) not only are unnecessary (because successfully resuscitated patients tolerate a
period of relative hypovolemia and low cardiac output), but
also risk failure by driving up intravascular volume and
edema formation precisely when the microvasculature is at
its most permeable [32].
Echocardiography can be particularly helpful in assessing
the etiology of low cardiac output. Previously healthy patients
demonstrate increased contractility and hypovolemia during
the early phases of burn shock [14]. Less commonly, echocardiography may reveal impaired contractility, indicating a
potential role for an inotrope.
Because burn injury results in a rapid and sustained
increase in SNS activity and catecholamine production [12,
33], for many years the use of vasoactive medications to treat
hypotension during burn shock was discouraged in favor of
volume loading. This is no longer the case. A recent European
Society of Intensive Care Medicine (ESICM) Burn ICU
working group survey stated that 80% of respondents use
vasopressors to reduce volume administration during the first
48 hours postburn [34]. But how best to use vasopressors is
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L. C. Cancio and J. M. Cancio
Fluid infusion
rate
Plasma
volume Urine output
May increase
to peak at hour
8–10
Oliguria is
common
Adequate Slowly
Decreases at
its most rapid
rate
Nadir at
Rapidly
reaches peak
Decreases
decreases
hour 12–18,
then slowly
increases
toward normal
Reaches a
maintenance
rate
target
nadir
Postburn
hour Cardiac output SVR
T . Time course of key variables during a typical successful resuscitation
Stage
1 0–12 Rapidly reaches
normal
2 12–36 Slightly less than
3 36–beyond Supranormal Subnormal Normal Often above
SVR Systemic vascular resistance
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