Burns Flashcards
1
Q
Etomidate and burns
A
- causes adrenocortical suppression (inhibits cholesterol conversion to cortisol)
- occurs with repeated administrations
- riskier in pts who are stressed: sepsis, hemorrhage, burn injury
2
Q
succinylcholine and burns
A
- causes massive hyperkalemia as denervated muscle membrane acts like a large receptor in its chemical sensitivity to succinylcholine
- sensitivity will develop within days, and lasts for several months
3
Q
First Degree Burn
A
epidermal injury (sunburn)
4
Q
Second Degree Burn
A
Into the dermis
5
Q
Third Degree Burn
A
- full thickness burn involving destruction of the epidermis and dermis
- spontaneous regeneration not possible
- graft usually required
6
Q
Rule of nines: Adult
A
9% head, each arm
18% each leg
36% trunk (18% anterior, 18% posterior)
7
Q
1 year old
A
19% head
9.5% each arm
15% each leg
32% trunk
8
Q
Pathophys: circulation
A
- cardiac output falls (due to dec intravascular volume–>dec preload)
- patients hyperdynamic by 2nd post-burn day, lasts 3-4 weeks
9
Q
pathophys: respiratory
Upper airway obstruction
A
- secondary to swelling
- secure airway before intubation more difficult
- except for steam inhalation injury, direct thermal injury to airways doesn’t occur below level of vocal cords b/c of efficiency of cooling in upper airways
10
Q
pathophys: respiratory
chemical pneumonitis
A
- due to smoke inhalation
- increased pulmonary shunting and hypoxia
- FRC and pulmonary compliance are decreased with increase in A-a gradient (FRC decreased below closing capacity)
- minute ventilation increases dramatically
- often no physical signs during first 24 hrs post-burn–singed nasal hair, burned nasal or oral mucosa
11
Q
pathophys: intravascular volume deficits
A
- vasculature permeable to plasma proteins, and these leave vascular space and exert osmotic pressure–>large fluid losses
- colloids should not be given
- Parkland formula: crystalloid 4 cc/kg/% burned in first 24 hrs, 1/2 first 8 hrs, 1/4 second 8 hrs, 1/4 thrid 8 hrs
12
Q
pathopys: GI tract
A
- adynamic ileus in burns >20% body surface area
- curling’s ulcer: acute ulceration in stomach=GI hemorrhage
- metabolic rate can more than double
13
Q
pathophys: renal
A
- dec in CO and intravascular fluid volume–>Dec in GFR
- red cell destruction–>myoglobinuria and hemoglobinuria
- need to maintain UOP, fluids, mannitol, lasix, PA cath
14
Q
pathophys: sepsis
A
- superficial infxn of burned area–delays wound healing, septic shock
- beta-hemolytic strep/staph GN contaminate wound–rx w/ silver nitrate
- silver nitrate can produce methemoglobinemia
15
Q
pathophys: DIC
A
DIC, hypothermia
16
Q
Ketamine
A
- for dressing changes
- 2 mg/kg IV, 4 mg/kg IM
17
Q
ketamine: advantages
A
- analgesia and dissociation
- sympathetic stimulation
- minimal respiratory depression
18
Q
ketamine: disadvantages
A
- psychic effects
- excessive salivation–can cause laryngospasm
19
Q
nondepolarizers
A
- more resistant to nondepolarizers
- pseudocholinesterase levels are dec 5-6 days after burn injury and level can be depressed several months
- inc number extrajunctional receptors
- pts with >25% total body area burned require NM blocker 3-5 x greater than nl
20
Q
depolarizers
A
- more sensitive to succs
- dec level pseudocholinesterase
21
Q
electrical burns
A
- small areas of skin necrosis, large amt of muscle damage
- huge fluid losses
- kidney at risk–large amt of myoglobin released–give IVFs, mannitol, lasix
- cardiac conduction abnormalities
22
Q
carboxyhemoglobin
A
- binding of hemoglobin to CO–binds at the same point as O2 therefore competes with O2
- CO 250 times stronger binding than oxygen
- CO partial pressure 0.4 mmHg equivalent to PaO2 of 95-100 (binds 50% hemoglobin)
- CO partial pressure of 0.7 mmHG will bind all available Hg
23
Q
amt of CO in people
A
- nonsmokers: 1-3% from auto emissions
- smokers: 4-8%
- fire victims: 100%
- carboxyhemoglobin levels depends on how
24
Q
PaO2
A
- measure of dissolved O2 in blood
- can be nl in setting of carboxyhemoglobinemia
- chemoreceptors are not stimulated because PaO2 remains normal
25
Q
rx CO
A
-high partial pressures of O2, hyperbaric
26
Q
airway management in burns
A
- cooling of upper airway protects subglottic structures
- with thermal injury, this can be lost–edema of hypopharynx
- intubate if: inhaled steam, smoke, toxic fumes, hoarseness/stridor, face burned
- edema worsened by IVFs
- emergent trach in burn pt has high mortality
27
Q
toxic fumes
A
- fluorides, bromides, iodides can deminish cough reflex, have anesthetic properties
- local tissues rxn–inflammation, retained secretions, bronchspasm
