Trauma Burn Flashcards
Preferred method of management for burn pts now?
early excision and grafting
AT 12-15% of O2 in the air, what toxicity symptoms does one exhibit?
muscular coordination for skilled movements lost
At 10-14% of O2 in the air, what toxicity symptoms does one exhibit?
judgement is faulty and and muscular effort leads to rapid fatigue
At 6-8 % O2 in the air, what symptoms are seen?
collapse, rapid treatment would prevent fatal outcome
Death occurs in 6-8 at what percent of oxygen?
6 or below
4 etiologies of burns?
chemical, thermal, electrical, inhalation
This degree burn involves the top layer of the epidermis only?
1st degree
Characteristics of 2nd degree burn?
blisters, epidermis and dermis- may involve all of dermis
Characteristics of 3rd degree burn?
deeper tissues past nerve endings, SQ
Can you have blisters with 1st degree burn?
yes
Characteristics of 1st degree burn?
red, painful, blisters, epidermis destroyed, superficial, heals spontaneously-no scarring
What type of burn is a 2nd degree burn?
partial thickness
What are the 2 types of 2nd degree burns?
superficial dermal and deep dermal
Characteristics of a superficial dermal burn?
epidermis and upper part of dermis. heals spontaneously. red or pale ivory, moist shiny surface, painful, immediate blistering, minimal scarring
Characteristics of deep dermal burn?
deep dermis, often involves incision and grafting for repair, mottled w white waxy dry surface, may or may not have blisters, significant scarring
Characteristics of third degree burn?
full thickness- epidermis and dermis, white, cherry red, or black, dry, tissue paper skin, needs grafting, decreased scarring w early excision
Characteristics of 4th degree burn?
muscle, fascia, bone, complete excision required, limited function
Characteristics of electrical burns?
total BSA % difficult to estimate, tissue damage is often more than it looks, renal problems electrical current may cause neuro probs, cardiac damage- arrythmias that persist for months
3 renal complications seen w electrical burns?
myoglobinuria, hemoglobinuria, renal failure
3 ways to manage the renal complications seen with electrical burns?
UO 1-1.5mL/kg/hr, mannitol and lasix, bicarb to alkalinize urine
Think of an electrical injury as what type of injury?
crush
Ferning is associated with what type of burn injury?
lightning strike
Why is eschar bad?
it is great for infection, it is hard and traps pressure, won’t ever heal
How can a 2nd degree burn turn in to a 3rd degree burn?
infection and cellulitis
What is considered a major burn in a normal adult?
2nd degree >10% TBSA
What is considered a major burn in age extremes?
2nd degree >20% TBSA
2 other types of burns that are major burns?
any electrical burn, burns complicated by smoke inhalation
The mortality is >80% w what formula?
age + TBSA% >115
Morality is doubled in a burn if what other type of injury also occurs?
inhalation injury
In rule of 9s, which body surfaces are 9% front and back?
upper and lower torso, and both legs (4)
3 most common causes of demise in burn pts?
septic complications, burn shock, MI >45 years
What is the normal water loss per m2/hr in a healthy human?
15-21 mL/m2/h
What is the water loss in m2/hr in a burn patient?
200 mL/m2/h
What is the latent heat of evaporation of water?
585 cal/H20
2 reasons why excessive evaporation is bad?
causes tremendous loss of heat, contributes to increased metabolic demands
How long does revascularization take in full thickness and partial thickness burns?
full thickness: 3-4 weeks, partial thickness: 24-48 hours
Capillary permeability is altered how in a burn patient?
biphasic pattern
why is there a reduction in circulating volume in burn patients?
severe translocation of fluid from intravascular space to the interstitial compartment
The major portion of increased capillary permeability occurs when with a burn pt?
first 12 hours and persists 2-3 weeks
Whats the cause of increased cap permeability in burn pts?
heat damage releases vasoactive chemicals
When a burn exceeds what % of TBSA does 2x the loss of albumin occur not only in the area of the injury but the whole body?
30
What 2 things does losing albumin to the extravascular space do?
severe hemoconcentration and red cell destruction
When does hemolysis occur in burn pts?
first 24 hours
Generally hemolysis does not exceed >8% of pre burn red cell mass unless…..?
exposure to prolonged heat such as in scalding
Burn patients have a remarkably reduced red cell survival time? What % of normal is it?
30
Protein leaking in to the extravascular space can persist up to how many hours?
36
Initial microbial invasion in burn pts is usually what type?
gram positive like staph
Day 5 of burn, what microbial infections persist?
gram negative like pseudomonas
What happens to CO in burn pt?
decrease. really decreased in severe burns, CO can drop 50%. myocardial depression due to increased proteins
When does burn shock occur?
24-36 hours after burn
When does CO drop after a burn?
immediately after
In large burns, CO drops 50% in the first 30 minutes and that is thought to be due to what 3 things?
release of myocardial depressant factor, increased blood viscosity, and release of vasoactive substances
CO slowly returns to baseline around how many hours after the burn and why?
36 hours, hypermetabolic state
What happens to PVR after a burn?
it increases in the first 3 hours then starts to decrease until 12 hours when it goes up again until 30 hours and then decreases
The three distinct syndromes of pulmonary injury in burn pts?
early complications, delayed injury, late complications
When do early pulmonary complications occur? What is an example?
0-24 hours post burn; carbon monoxide poisoning, direct inhalation injury can lead to airway obstruction and pulmonary edema
Delayed pulmonary injury occurs when? What is an example?
2-5 days after burn; ARDS
Late pulmonary injury occurs when and what are some examples?
days to weeks after injury, pneumonia, atelectasis, PE
What are some of the pulmonary complications from burn injury?
decreased FRC, decreased lung and chest wall compliance, increased alveolar-arterial gradient resulting in decreased capillary function, increased MV d/t increased O2 requirements and VQ abnormalities
What’s the patho leading to pulmonary edema
decreased CO + impaired vascular permeability + large IVF
This type of injury occurs when hot gasses, smoke particles, toxic substances reach the tracheobronchial tree
inhalation injury
4 complications from inhalation injury?
wheezing, bronchospasm, corrosion, airway edema
9 indications of inhalational injury?
closed space injury, facial burn, singed nose hairs, perioral burn, pharyngeal edema, hoarseness, carbonaceous sputum, bronchorrhea, wheezing
This burn injury is often associated w a person under the influence of drugs or alcohol?
inhalation
Signs of respiratory tract injury?
singed nasal hairs, burned nasal mucosa, lips or mouth, hoarseness, wheezing, soot in oro/nasopharynx, brassy cough with soot in sputum
4 ways to diagnose inhalational injury?
fiberoptic, ABGs, carboxyhg concen, xenon scan
Toxic components in smoke inhalation can cause what 4 things?
bronchospasm, impaired mucociliary ftn, ulceration of mucous mem, edema
In inhalational injury, damage to the lungs is almost always what in nature?
chemical (chemical pneumonitis)
Why does steam not affect the lungs?
rarely does enough steam get inhaled bc the specific heat of air is so low that it rarely reaches the carina w increased temps
What happens to surfactant production w inhalational injury?
it’s impaired
Why is O2 and CO2 exchange impaired w inhalational injury?
increased cap permeability damages alveoli and ciliary ftn is halted so secretions and bacteria accumulate
What is important to know about smoke inhalational injury?
the smoke inhalation signs often lag behind other events and the patients may rapidly deteriorate. prophylactically intubate!
How do you treat inhalational injury?
supportive, PEEP, O2 therapy and mech vent. typically gets worse for 1st 3 days after injury then improvement starts
Carbon monoxide has affinity for hg how many times that of O2?
200
What does ABG show in CO poisoning?
normal PaO2 but low O2 content, low SaO2
Why does CO poisoning not result in tachypnea?
carotid bodies are sensitive to arterial PaO2 and not arterial oxygen content so pts may be hypoxic but not tachypneic
20% carboxyhg level corresponds w what sx?
HA, mild dyspnea, visual changes, confusion
20-40% carboxyhg levels correspond w what sx?
irritability, decreased judgement, dim vision, N, easy fatigueabilitiy
40-60% carboxyhg levels correspond w what sx?
hallucinations, confusion, ataxia, collapse, coma
What % of carboxyhg levels is fatal?
60
Treatment for carboxyhg poisoning?
100% O2 NRB, intubate w decreased LOC, hyperbaric O2 treatment w high CO levels or symptomology
What’s the half life of carboxyhg?
3-4 hours
T/F: Fetal hg has higher affinity for carboxyhg than adults?
true
When does the hypermetabolic phase occur in a burn pt?
first few hours of a burn into the convalescent phase
6 characteristics of hypermetabolism?
catabolism and nitrogen wasting, hyperglycemia, hyperthermia, tachycardia, tachypnea, increased oxygen consumption, contributes to poor wound healing and immunosuppression
Good results w what treatment for hypermetabolism?
human growth hormone
What does a burn pt need during hypermetabolism phase?
increased oxygen, ventilation, nutrition
What happens to RBF and GFR in the hypermetabolic state?
they diminish immediately and activate the RAAS
ADH release causes retention of what and excretion of what?
retention of Na and H20; excretion of K, Ca, Mg
Hemoglobinuria is secondary to what?
hemolysis
Myoglobinuria is secondary to what?
muscle necrosis
What can hemoglobinuria and myoglobinuria lead to?
ATN and ARF
Oliguria is usually a sign of?
inadequate fluid replacement
Initially you want to maintain a UO of?
0.5 mL/kg/hr
In children
1mL/kg/hr
What do you have to worry ab w electrical burns in r/t renal failure?
myoglobinemia d/t extensive areas of devitalized muscle
How do you treat myoglobinuria and renal failure?
fluids and diuretics/mannitol
How can you reduce pigment associated renal failure?
give bicarb
5 ftns of burns on immune system?
decreased neutrophil chemotaxis and phagocytosis, impaired macrophage activity, increased T suppressor cells, poor leukocyte ftn, low immunoglobulin levels
Treatment for burn GI complications?
H2 blocker, antacids, NGT
GI complications d/t burn?
ileus, under perfusion of splanchic circulation and bacterial translocation from the gut to the systemic circulating leading to sepsis, gastric and duodenal mucosal injury (Curling’s ulcer)
Why is there a potential for abnormal liver ftn after burn?
shock
Why is there HTN after a burn?
increased catecholamines
Neurologic abnormalities are seen especially w what type of burn?
electric
Erythrocytes are damaged or destroyed by heat and removed by the spleen when after burn?
w/in 72 hours
What’s the Parkland formula?
4mL LR/ %TBSA burned/ kg. 1/2 given in 1st 8 hours and remaining over the next 16 hours
What are your alternative fluid solutions for burn pts?
hypertonic saline to maintain UO 0.5-1 mL/kg/hr; colloids not recommended w/in first 24 hours
3 factors which would increase volume of fluid needed to resuscitate?
delay in initiation, inhalation injury, high BAC at time of injury
when does airway edema develop in relation to the injury?
several hours after, gets worse for 2-3 days then begins to recede
When is airway edema the worst after a burn injury?
2-3 days after injury
Prophylactic intubation w what 2 signs?
signs of smoke inhalation or upper airway burn
Some considerations for intubating a burn pt?
tube size smaller than normal, topical, transtracheal or translaryngeal blocks, mild sedation, gentle
Leading cause of death in burn pts?
sepsis/infection
What is preferably used for sedation in burn pts?
narcs
First burn surgical excision is usually how many hours after injury?
24-48 hours
What do surgeons use to control the bleeding after harvesting grafts?
epi soaked sponges
What does the anesthetist have to pay attention to during grafting?
blood loss! there can be a lot
What do burns do to the muscle membrane?
denervation so proliferation of the extrajunctional receptors. unaltered for first 24 hours
When what %TBSA is burned does the excessive K release from suxxs occur?
> 10%
Which 2 types of injuries are immediately susceptible to the increased K from suxxs?
electrical burns and crush injuries
With burns > what TBSA % is there sensitivity to NMDRs?
30
Which NMDR are burn pts not sensitive to?
mivacurium
When does NMDR sensitivity start and stop?
starts 1 week after burn and peaks 5-6 weeks after injury
How do you adjust your NMDRs in sensitive pts?
larger and more frequent doses
What about the burn pt increases ventilatory requirements?
hypermetabolic state and VQ mismatches
Average adult MV at rest?
5L/min
What is the estimated blood loss formula for burn pts?
2.8%(+/- 0.2%) of circulating volume per % TBSA excised + 1.8%(+/-0.2%) of circulating volume per % TBSA grafted
What do you need to avoid with emergence in a burn pt?
shivering
Drugs administered by a route other than IV in a burn pt have what type of absorption?
delayed
When is the albumin concentration in a burn pt decreased?
after 48 hours
What are 2 drugs affected by the decreased albumin? (increased free concen)
benzos and anticoagulants
What is the change in the effect of drugs metabolized by the liver by oxidative metabolism (ie diazepam)?
prolonged
What is the change in the effect of drugs conjugated by phase II reactions in the liver (ie lorazepam)?
not affected
Why are opioid requirements increased in burn pts?
increased metabolism and habituation
