Burns Flashcards
functions of the skin
- barrier (body fluids/infection)
- temperature
- elasticity
- appearance
- sensory organ
three layers of skin
- epidermis
- dermis
- subcutis (hypodermis or sub q tissue)
types of burn in jury
- thermal –> flash, flame, scald
- chemical
- electrical
- radiological
classification of burns
- depth - extent of skin and tissue destruction
- superficial, partial thickness, full thickness
- TBSA - total body surface area involved (rule of nines)
superficial burn (1st degree)
-depth - destruction of epidermis
-pain level - very painful
-appearance - red
-characteristics - dry/flaky, will heal spontaneously in 3-5 days
THINK really bad sunburn
partial thickness burn (2nd degree)
- depth - superficial or deep; epidermis up to deep dermal element
- pain level - very painful (because exposure of nerve endings)
- appearance - bright cherry red, pink or pale ivory, usually with fluid filled blisters
- characteristics - hair follicle intact, may require skin graft
full thickness burn (3rd degree)
- depth - all of the epidermis, dermis, and down to the subQ tissue
- pain level - little or no pain
- appearance - khaki brown, white or charred/cherry red (in peds cherry)
- characteristics - loss of hair follicles, will DEF need skin graft
fourth degree
- depth is full thickness extending into the muscle and bone
- will 100p require skin graft and maybe need to be amputated
Rule of nines
- a way to classify the TBSA burned
- NOTE = different for peds and obese individuals
head rule of nines
9% TBSA
upper extremities rule of nines
18% TBSA
each arm = 9%
trunk rule of nines
36% TBSA
front/back = 18% each
lower extremities rule of nines
36% TBSA
each leg = 18%
genitals rule of nines
1% TBSA
burns that should be transferred to burn center
- full thickness in ANY age group
- partial thickness >10% TBSA
- burns of special areas
- extreme of age
- burns of face, hands, feet, perineum or major joint
- inhalation, chemical or electrical burns
- those burns associated with co-existing disease
mortality of burns
- if the age of the patient plus the TBSA % is greater than 115 the mortality is greater than 80%
- associated injuries increase mortality (inhalation injury and other trauma)
- premorbid condition
resuscitative phase burns
- similar to trauma
- initial treatment involves airway, breathing, circulation, coexisting trauma
assessment of burn patient source of injury
- closed space thermal injury equates to airway injury
- open space accidental injury (campfire) or MVC = multiple co-existing injuries
- electrical injury may lead to occult - severe fractures, hematoma, visceral injury, skeletal, cardiac injury, neurologic injury
airway management in burn patient
- aggressively r/o upper airway injury in patient at risk (closed space injury, unconsciousness)
- diagnosis is made by history and physical exam
S/S airway complications
- singed facial hair
- facial burns
- dysphonia/hoarseness
- cough/carbonacous sputum
- soot in mouth/nose
- swallowing impairment
- oropharynx inflammation
- CXR initially normal (until pulmonary edema or infiltration develops)
inhalation injury
-refers to damage to the respiratory tract or lung tissue from heat, smoke, or chemical irritants carried into the airway during inspiration
upper airway involvement inhalation injury
- thermal damage to soft tissues of the respiratory tract and trachea can make intubation difficult
- thermal injury plus fluid resuscitation
- increases the risk or glottic edema
lower airway involvement inhalation injury
- pulmonary edema/ARDS develops 1-5 days post-burn
- pneumonia and pulmonary embolism >5 days post burn
smoke inhalation
- occurs in conjunction with face/neck burns and closed space fires
- chemical pneumonitis similar to gastric aspiration occurs after smoke/toxic fume inhalation
- honeymoon period in 1st 24 hours with clear CXR
- decreased PaO2 on RA is 1st sign
- increased sputum with rales/wheeze
first 36 hours inhalation injury
high risk of pulmonary edema
days 2-5 inhalation injury
expect atelectasis, bronchopneumonia, airway edema max secondary to sloughing of airway mucosa, thick secretions, distal airway obstruction
> 5 days post-burn inhalation injury
nosocomial pneumonia, respiratory failure, ARDS
circumferential burns of chest/upper abdomen
- restricted chest wall motion as eschar contracts and hardens
- may need escharotomies to allow for proper chest expansion with respiration
pulm/airway management in inhalation injury
- serial laryngoscopic/bronchoscopic exams
- CXR
- ABGs
- PFTs
- 100% FiO2
- prophylactic intubation if deterioration likely
- intubation technique depends on patient factors, extent of damage, age, and co-existing disease
- adults = fiberoptic intubation under adequate topical anesthesia is safest is they can cooperate
- peds = smaller diameter airway so LOW threshold for intubation
ETT indicators for inhalation injury
- massive burn
- stridor
- respiratory distress
- hypoxia/hypercarbia
- altered LOC
treatment of hypoxia in those with inhalational injury
- PEEP
- airway humidification
- bronchial suctioning/lavage
- bronchodilators
- abx
- chest physiotherapy
carbon monoxide toxicity
- CO poisoning and smoke inhalation usually found together
- CO 200x affinity for Hgb as O2
- CO shifts Hgb dissociation curve LEFT so impairs O2 unloading at tissue
- may act as myocardial toxin and prevent survival of cardiac arrest
- SaO2 may be normal
- respiratory effort may appear normal
- cherry red blood color may not be present if CO is < 40% and/or patient is cyanotic and hypoxic
CO interferes with…
- mitochondrial function
- uncouples oxidative phosphorylation
- reduces ATP production
- result is metabolic acidosis
CO toxicity treatments
- high FiO2 on all burns until CO tox ruled out
- hyperbaric chamber if COHgb is > 30% and patient is hemodynamically and neurologically stable
CO <15-20%
HA, dizziness, confusion
CO 20-40%
nausea, vomiting, disorientation, visual impairment
CO 40-60%
agitation, combative, hallucinations, coma, shock
CO >60%
death
cyanide toxicity + BURNS
- cyanide (CN) is produced as synthetic materials burn
- victims inhale and absorb it through mucuous membranes
- metabolic acidosis is result with elevated lactate levels
S/S cyanide toxicity
- altered LOC w/ agitation, confusion, coma
- CV depression + arrhythmia risk
diagnosis cyanide toxicity
blood cyanide levels of >0.2 mg/L
LETHAL = 1.0 mg/L
cyanide toxicity treatment
- O2 is treatment of choice
- others = hydroxycobalamine (vit B12 derivative), amyl nitrate, sodium nitrate, thiosulfate
CN half life
60 min
systemic effects of burn injury
- release of inflammatory mediators locally at the burned tissue and systemically contribute to edema associated with burn injury
- increase in microvascular permeability –> fluid leak and loss of proteins
- increased intravascular hydrostatic pressure/decreased interstitial hydrostatic pressure
- interstitial osmotic pressure increases
- surgery and infections can perpetuate this mediator induced systemic inflammatory response that may lead to multiple organ failure
CV stresses with burns
- severe decrease in CO lasts first 24 hours
- circulating TNF causes myocardial depression
- diminished response to catecholamines
- increased microvascular permeability hypovolemia
- intense vasoconstriction compensation
- decreased tissue oxygen supply and coronary blood flow
- hemolysis of erythrocytes
- after 24-48 hours hyperdynamic state (high output CHF) - increased BP, HR, CO 2x normal
overall systemic results with burns
- immune suppression
- activation of the hypothalamo-adrenal axis and the RAAS
- hypermetabolism
- protein catabolism
- sepsis
- MSOF
metabolism in burn patient
- increased metabolic rate is proportional to TBSA burned (can double in 50% TBSA)
- increased core body temp reflects increased metabolic thermostat
- loss of skin = loss of vasoactivity, piloerection, insulation functions
- daily evaporative fluid loss is 4000 mL/m2
- caloric consumption is increased
GI end organ complications with burns
ileus
ulceration
cholecystitis
renal end organ complications with burns
decreased GFR, RBF, loss of Ca, K, Mg with retention of Na, H2O
endocrine end organ complications with burns
increased corticotropin, ADH, renin, angiotensin, aldosterone, increased glucagon, insulin resistance, hyperglycemia (at risk of nonketotic hyperosmolar coma)
blood/coagulation end organ complications with burns
increased viscosity, increase in clotting factors including fibrinogen, V and VIII, fibrin split products at risk fo DIC development, HCT usually decreases
burns fluid resuscitation
- loss of fluid from vascular compartment 1st 24 hours –> replace with 2-4 mL/kg for each 1% TBSA burned
- titrate fluids to u/o 0.5-1 mL/kg/hr
- dont over do it!!!! over aggressive fluids can worsen airway edema, increase chest wall restriction, and contribute to abd compartment syndrome
- 1st 24 hours cyrstalloid ONLY
- > 24 hours colloids at 0.3-0.5 mL/kg/% burn, with 5% dextrose in water
parkland formula
4 mL LR/kg/%burn/1st 24 hours
modified brooke formula
2 mL LR/kg/%burn/1st 24 hours
calculated volumes are given
- 50% 1st 8 hour
- 25% 2nd 8 hour
- 25% 3rd 8 hour
albumin 5%
can give after 1st 24 hours
0.3-0.5 mL/kg dose on burn extent
goals of fluid resuscitation
- UOP 0.5-1 mL/kg/hr
- HR 80-140 bpm
- MAP adults > 60 mmHg
- base deficit < 2
- normal Hct
fluids not enough for burns?
- low dose dopa 5 mcg/kg/min
- consider other vasopressor
anesthesia considerations in burn patient
- repeated surgeries
- maintain HCT multiple transfusions
- coagulopathy
- temperature
- fluids and lytes
- hypermetabolic state = increase O2, ventilation, nutrition
- increased risk for GI ileus, aspiration/hyperalimentation
anesthesia challenges in burn patient
- monitors, burned tissue = limited access for ECG, SaO2, PNS, NIBP
- need large bore IV access - may consider alternative areas for placement
- compensate for evaporative/exposure heat loss - room temp 28-32 degrees C
- minimize blood loss - topical/SQ epi, only 15-20% TBSA q procedure, tourniquets
- treat the complications of massive transfusion
pre-op evaluation
- airway
- phase of resuscitation
- monitoring
- intravascular access
- equipment
anesthesia considerations for the high voltage electrical injury
- follows path of least resistance, bone most resistant
- cardiac arrhythmias
- respiratory arrest
- seizure
- fractures
- muscle damage –> myoglobinurea –> renal failure
pharm for burn patients
- HIGH opioid requirement
- ideal anesthetic choice is iso + large dose opioid
- serial debridments = ketamine in incremental doses
- regional not normally option
- muscle relaxants - in first 24 hours can use depolarizing and NDMR
- after first 24 hours cannot use succ d/t mass K+ release b/c proliferation of nAChR
- resistance to most NDMR if >30% TBSA
