Burns Flashcards
What is the classification of burns based on percentage?
MILD (minor)
- partial thickness <15% in adult or <10% in children
INTERMEDIATE
MAJOR (SEVERE)
- 2nd degree burns >30% in adults & >20% in children
- all 3rd degree burns 10% or more
- burns involving eyes, ears, feet, hands, perineum
- all inhalation & electrical burns
- burns with fractures or major mechanical trauma
What is the classification of burns depending on thickness?
First degree: red & painful
Second degree: mottled, red, painful with blisters
Third degree: charred, painless & insensitive
Fourth degree: involves muscles & bones
How does a first degree burn heal?
epithelialization in 5-7 days without scarring
How do 2nd degree burns heal?
epithelialization in 14 - 21 days
- SUPERFICIAL: healing causes pigmentation
- DEEP: healing cases scarring & pigmentation
How do 3rd degree burns heal?
- require GRAFTING
- charred, denatured, insensitive, contracted full thickness burn is called ESCHAR
How do we assess burns based on surface area in adults?
HEAD & NECK -> 9% FRONT OF CHEST -> 9% FRONT OF ABDOMEN -> 9% BACK OF CHEST -> 9% BACK OF ABDOMEN -> 9% LOWER LIMB -> 18% UPPER LIMB -> 9% PERINEUM -> 1%
How do we assess burns based on surface area in children?
HEAD & NECK -> 18% FRONT OF CHEST -> 9% FRONT OF ABDOMEN -> 9% BACK OF CHEST -> 9% BACK OF ABDOMEN -> 9% LOWER LIMB -> 13.5% UPPER LIMB -> 9% PERINEUM -> 1%
What are the clinical features of a burn?
- history of burn
- pain, burning, anxious status, tachycardia, tachypnea, & fluid loss
- if severe -> shock (tolerable temperature is 40 for a brief period)
- massive edema
What is the pathophysiology of burns?
1- coagulation necrosis of skin & subcutaneous tissue
2- vasoactive peptides
3- altered capillary permeability
4- loss of fluid
5- severe hypovolemia
6- decreased cardiac output
7- decreased renal blood flow -> oliguria
8- altered pulmonary resistance -> pulmonary edema
9- infection
10- SIRS
11- MODS
What is the cause of cardiac dysfunction due to burns?
HYPOVOLEMIA
hormonal (catecholamines, vasopressin, angiontensins)
What are the causes of pulmonary changes due to burns?
- altered ventilation-perfusion ratio
- pulmonary edema (burn injury or inhalation injury)
- ARS & aspiration
- Septicemia
What is the cause of renal changes in burns?
- release of ADH from posterior pituitary to cause maximum water reabsorption
- release of aldosterone from adrenal to cause maximum sodium reabsorption
- toxins from the wound & sepsis causes ATN
- myoglobin released from muscles (electric injury or eschar)
- incompatible blood transfusion -> hematoglobinuria
- circumferential eschar -> compartment syndrome
when should be assess airway injury?
in burns around face & neck OR trapped in a room
requires early elective intubation or tracheostomy
Why is assessment of airway injury VERY important in burns?
- BURNING GASES -> upper airway burns, laryngeal edema, hoarseness, or stridor
- SMOKE INHALATION -> chemical alveolitis, pulmonary edema, ARDS & respiratory failure
- STEAM INHALATION -> damage to respiratory epithelium & subglottic edema
- CARBON MONOXIDE -> has higher affinity to hemoglobin
- CHEST WALL BURNS -> mechanical block of ventilation
What are the causes of GIT changes in burns?
- acute gastric dilatation (occurs in 2-4 days)
- paralytic ileus
- Curling’s ulcer (erosive gastritis due to stress)
- Cholestasis & hepatic damage
What are the metabolic changes that occur in burns?
- Hypermetabolic rate (catabolic state)
- electrolyte imbalance
- vitamin & essential element deficiencies
- metabolic acidosis due to hypoxia & lactic acid
What is the most common cause of infection in burns?
streptococci (beta hemolytic)
What are the effects of burn injury?
- hypovolemic shock
- renal failure
- pulmonary edema, respiratory infection, ARDS, respiratory failure
- bacteremia or septicemia
- ischemia of mucosa, erosive gastritis (Curling ulcer) in burns >35% due to hypovolemia
- post burn immunosuppression -> opportunistic infections
- eschar -> defective circulation & ischemia when circumferential
- DVT, pulmonary embolism, bed-sores, severe malnutrition with catabolic status
- hypertrophic scar, keloid
- toxic shock syndrome
What are the effects of electrical injuries?
fractures, major internal organ injury, convulsions
A burn patient later develops contracture, what could it lead to?
- ectropion -> keratitis & corneal ulcer
- microstomia
- disability of different joints
- defective hand functions
- growth retardation causing shortening
- hypertrophic scar & keloid
- repeated breaking of scar, infection, ulcer, cellulitis
- pain & tenderness in scar contracture
- Marjolin ulcer (squamous cell carcinoma)
What will chemical injury lead to?
severe GIT disturbances
erosions, perforation, stricture esophagus (alkali), pyloric stenosis (acid)
What is the cause of death in burns?
- hypovolemia & shock
- renal failure
- pulmonary edema & ARDS
- septicemia
- multiorgan failure
What are the indications for admission in burns?
- any moderate or severe burns (>15%)
- airway burns of any type
- burns in extremes of age
- all electrical/deep chemical burns
What is the initial management that should be done for a burn victim?
1- remove clothing 2- cool with running water for 20 mins 3- clean part to remove dust or mud 4- chemoprophylaxis (tetanus toxoid - antibiotics - local antiseptics) 5- cover with dressing 6- comfort with sedation & pain killer
What is the first aid management of burns?
- stop burning process
- cool area with tap water by continuous irrigation for 20 mins
What is the definitive treatment in burns?
- admit patient
- ABC
- assess percentage, degree, & type of burn
- keep patient in a clean environment
- sedation & proper analgesia
- patient should be in burn unit
What is Parkland’s regimen?
fluid replacement calculation (CRYSTALLOIDS)
4ml/kg/% of burn in 24 hours
HALF is given in first 8 hours
the rest is given in 16 hours
What is the modified Brooke formula?
FIRST 24 HOURS
- RINGER’S LACTATE 4ml/kg/% of burn first half in first 8 hours
SECOND 24 HOURS
- CRYSTALLOIDS: maintain urine output
- COLLOIDS: 0.3ml to 0.5ml/kg/burn % in 24hrs (albumin in RL)
What is Evan’s formula?
FIRST 24HRS
- crystalloids 1ml/kg/burn % + colloids 1ml/kg/burn% + 2000ml 5% dextrose
SECOND 24HRS
- half of the volume used in first 24hrs
after fluid resuscitation what should be done?
- urinary catheterization to monitor output
- tetanus toxoid
- monitor hourly (pulse, BP, PO2, PCO2, electrolytes, blood urea..)
- IV omeprazole (Ranitidine) 50mg 8th hourly
- Enteral feeding
- Antibiotics
- culture of discharge
- TPN (total parenteral nutrition) for faster recovery
What local management should be done for burns?
- dressing (under GA if large surface area) using paraffin gauze, hydrocolloids, plastic films, vaseline impregnated gauze or fenestrated silicone sheet
- open method using SILVER SULFADIAZINE in face, head & neck (isolate patient)
- closed method with dressing done to soothen & to protect the wound, reduce pain & absorb
When can tangential excision of burn wound with skin grafting be performed?
within 48 hours in patient with <25% burns
What topical agent boosts cell mediated immunity & forms sterile eschar?
Silver sulphadiazine & cerium nitrate
What topical agent is used on granulation tissue after eschar separation but is VERY IRRITANT & PAINFUL?
Povidone iodine 5%
which topical agent penetrates very well into tissues but is very irritant & painful & could cause acidosis?
Sulfamylon 5% (mafenide acetate)
What is eschar?
- charred, denatured, full thickness deep burns with CONTRACTED DERMIS
- insensitive thrombosed superficial veins
What is the effect of a circumferential eschar & what should be performed?
can increase edema in upper & lower limbs, neck & thorax -> venous compression -> arterial compression -> ischemia, gangrene of distal parts
- ESCHAROTOMY to prevent collection of fluids & compression
What is the side effect of escharotomy?
causes large quantity of blood loss
BLOOD TRANSFUSION IS NEEDED while doing it
if there is early rapid eschar separation, what does that indicate?
severe sepsis underneath
repeated silver sulphadiazine application could lead to?
pseudoeschar (thickened burnt skin)
What does Marjolin’s ulcer look like & how is it treated?
- raised & everted edge with fixed induration base & necrotic floor
- if it spreads out of scar tissue it can spread to regional lymph nodes
- wide excision or amputation
How is contracture treated?
- Z plasty or flaps
- proper physiotherapy & rehabilitation
- pressure garments to prevent hypertrophic scars
- itching in scar tissue -> aloe vera, antihistamines, & moisturizers
How do we prevent the development of contracture?
- joint exercise in full range during recovery period of burns
- pressure garments for a long period
- topical silicon sheeting
- saline expanders for scars
What are the types of electrical injury?
low tension
high tension
- flash injury -> electrical arc up to 4000C
- flame injury -> catching fire to clothing & body
- traumatic injury -> fractures & internal organ injuries
What does a high tension electrical injury cause?
- always deep burn (major 3rd degree)
- wound of entry & exit
- convulsions
- cardiac arrhythmias (instant death due to VF)
- gas gangrene is common
- myoglobin release can cause renal tubular damage & renal failure
- acidosis
- fractures & dislocations
How is an electrical injury managed?
- Mafenide acetate: penetrates well & useful against clostridial infection
- Mannitol: to prevent myoglobin induced renal failure
- wound excision, amputation, surgery for internal organ injury, cardiac monitoring
how is inhalation injury caused?
- inhalation of heat
- oxygen concentration is less than 2% at site of fire -> death in 45 seconds due to hypoxia
- inhaled carbon monoxide bind with hemoglobin immediately -> severe anoxia & death
- hydrocyanide -> tissue hypoxia & acidosis
- laryngeal edema & laryngospasm
What are the symptoms of carbon monoxide intoxication?
- headache
- disorientation
- visual changes
- fatigue
- vomiting
- hallucinations
- shock
- cardiac arrest
What are the clinical features of carbon monoxide poisoning?
- low oxygen saturation
- charring of mouth, oropharynx with facial burns
- carbon sputum
- changes in voice
- singed facial & nasal hair
- decreased level of consciousness with stridor or dyspnea
How should a patient with carbon monoxide intoxication be managed?
- move patient from site ASAP
- ventilator support
- antibiotics
- bronchoscopy
- tracheostomy
What does a chemical burn cause?
tissue destruction more progressive
always a deep burn
What does an acid burn cause, and where does it occur?
in skin, soft tissues, & GIT
- GIT -> NITRIC ACID or SULPHURIC ACID -> severe gastritis or pyloric stenosis
- HYDROFLUORIC ACID -> metabolic acidosis, renal failure, ARDS, or hemolysis
What does an alkali burn cause?
saponification of fat, fluid loss, release of alkali proteinates & hydroxide ions (toxic)
How should a chemical burn be treated?
- dilution with water for at least 20 mins
- neutralization with antidote is done later
- mannitol diuresis, hemodialysis, calcium gluconate
- IV, pain relief, serum electrolyte management, TPN, ventilator support
- later -> reconstruction of face
What is esophageal dilatation or colonic transposition done for?
esophageal stricture due to alkali burn
what is gastrojejunostomy done for?
acid induced pyloric stenosis
