Week 9 - Burns Flashcards
What is the ABCDE emergency management of sever burns?
Airway – c-spine
Breathing – 100% O2
Circulation – hemorrhage control and IV access
Disability – AVPU & Pupils
Exposure – environmental control and estimate TBSA
*Fluids, Analgesia, Tests, Tubes
Who is at higher risk for burns?
- The very young (children 4 and under)
- The very old (65+)
- The very careless
- African Americans & Native Americans
- The poor
- Rural Americans
- People living in substandard housing
What are the functions of the skin?
- Protects underlying tissues from injury
- Assists with temperature regulation
- Acts as a water seal, keeping body fluids inside the body
- Sensing organ
What does perforation, burns, and other injuries to the skin lead to?
Infection
Inability to maintain fluid and electrolyte homeostasis
Inability to maintain normal body temp
What are the layer of the skin?
Epidermis (outer layer)
- outer most layer is made up of dead skin cells
- underneath layers seal and protect the body
Dermis (layer below the epidermis)
*only the EPIDERMIS can regenerate
What are the different classifications of thermal (heat) burns?
Depth: superficial vs partial thickness (superficial or deep) vs full
Degree: 1st, 2nd, 3rd, 4th
What are the signs and symptoms of a superficial 1st degree burn?
- Erythema
- Pain at the site
- Only involves epidermis
- No blisters
- Heals in 3-6 days
*Sunburn
What are the signs and symptoms of a partial thickness 2nd degree burn?
- Entire epidermal layer is burned
- Some of the dermis may be involved
- Mottled, red, painful blisters
- Heals in 10-21 days
- Epithelium will still regenerate
*BAD sunburn
What are the signs and symptoms of a full thickness 3rd degree burn?
- Epidermis and dermis destroyed
- Burns into the subQ and fat
- Skin is charred, leathery & woody
- NOT painful (nerve endings burned
What are the signs and symptoms of a full thickness 4th degree burn?
- Extend into the muscle, bones, and tendons
- Black and dry
- No Pain
- Eschar forming/formed
- Frequently involves amputation
What is the rule of nines for the adult?
Head = 9% Each arm = 9% Torso = 18% Back = 18% Each leg = 18% Genitalia = 1%
What is the rule of nines for a child?
Head = 18% Each arm = 9% Torso = 18% Back = 18% Each leg = 14%
What is an electrical burn?
Electricity flows from an area of high to low concentration through a conducting material
- the body is the conducting material
- the duration of contact determines the extent of the burn
- the width of the current pathway determines damage
- the tissue through which it passes determines the damage
*nerve damage can develop/worsen over years
What cardiovascular issues occur with electrical burns?
- V-fib
- Aystole
- Conduction abnormalities
- Trauma to cardiac muscle
*survivors have long-term arrhythmias, sinus tachy, PVCs
What respiratory issues occur with electrical burns?
- Tetanic contraction of the chest wall muscles may cause respiratory arrest
- Injury to the cerebral respiratory control centers may cause respiratory arrest
- Lungs usually don’t conduct well so they do OK
What neurological issues occur with electrical burns?
- Spinal fractures and other CNS injuries due to blunt force from secondary falls, etc
- Transient confusion, amnesia, confusion, lack of recall
- Long-term may include seizures, nerve damage, psych issues
What musculoskeletal issues occur with electrical burns?
- Fractures from blunt trauma and falls secondary to being burned
- Compartment syndrome from burns
- Massive muscle damage may cause Rhabdomyolysis and kidney failure
What head issues occur with electrical burns?
Entry point for electricity
- Facial burns
- Tympanic membrane rupture
- C-spine injuries
- Cataracts ~6% of electrical burn pts
What type of injuries does acid chemical burns cause? Basic chemical burns?
Acids produce a coagulation necrosis by denaturing proteins
-forms eschar which then limits the depth of acid penetration
Basic chemicals produce liquefaction necrosis – more severe
*chemical burns damage continues until the substance is removed (washed vigorously) or neutralized
What is the main cause of death in burn patients?
Inhalation Injuries
- secondary to airway constriction (Hagen Poiseuille law)
- inhalation injuries are usually limited to the upper airways
When do lower airway inhalation injuries occur?
Overwhelming heat exposure
Inhalation of steam
Aspiration of hot liquids
How do you predict patient survival after a major burn?
Baux Score: age + TBSA or age + TBSA + 17 with inhalational burn
- burn size >40% relative risk increases by 12
- age >50 RR 7.3
- inhalation injury RR 3.6
- male RR 1.8
When should you be concerned the patient might have an inhalation burn injury?
- Fire in a closed space
- Burn pt was entrapped
- Pt is unconscious or other neurologic altered LOC
- Facial burns
- Perioral burns, singed nose hair, carbonaceous sooty sputum
- Respiratory compromise or dropping SaO2 readings
What do inhalation burn injuries cause?
- Mucociliary impairment which leads to respiratory infections
- Mucus hypersecretion
- Bronchitis, laryngitis, and pneumonia
- Epithelial sloughing in airways
- Surfactant inactivation due to biochemical alterations
- Increased pulmonary vascular permeability (ARDS)
- Airway obstruction (large early and small later)
- Carbon monoxide poisoning
What direction does carbon monoxide shift the oxyHgB curve?
Shifts the OxyHgB curve to the left – leading to hypoxia
- CO has an affinity for Hgb that is 200x greater than oxygen
- standard pulse ox cannot detect CO so readings are WNL (reason every burn pt gets oxygen no matter what)
How do you treat carbon monoxide poisoning?
Place EVERYONE on 100% non-rebreather face masks
-half life of COHgb on room air is 4 hours and on 100% O2 it is decreased to 30 min
What is included in the airway component of burn patient resuscitation?
- Avoid CO poisoning issues w/ 100% humidified non-rebreather
- Observe face and airways for signs of impending airway obstruction (prophylactic intubation preferred to emergency intubations)
- Continue to observe for worsening upper airway edema (first 8 hours is critical)
- Avoid chest wall restriction via circumferential burns (escharotomies)
- HOB elevated 30 degrees to decrease head and neck edema
What is included in the circulatory component of burn patient resuscitation?
- Intravascular volume shifts interstitial due to increased capillary permeability (hypoproteinemia, hyponatremia, interstitial edema)
- Massive fluid resuscitation
- Give fluids until hemodynamic stability, adequate urine output (1/2 cc/kg/hr), adjust as needed dependent upon other patient factors
What is the parkland formula for burn patient fluid resuscitation?
4 mL/kg/%BSA/24 hours of LR
-half in first 8 hours and half in next 16 hours
What are the different surgical managements for burns?
- Emergent escharotomies and fasciotomies for decompression
- Excision and skin grafting to cover open skin areas
- Multiple debridement and skin grafting for reconstruction
- Others include trach, g-tube, ortho, neuro, ect
What are anesthetic considerations for the airway in a burn patient?
- Excellent preop airway examination is a must
- Intubated? what size tube, depth, duration
- Not intubated? were they, when, size/depth/duration
- Note previous ventilator mode and PIP used
- May need a smaller ETT than expected
- How will you secure the airway? – tape, suture, wire
What are pulmonary anesthetic considerations in a burn patient?
- Beware pulmonary edema and ARDS
- Burn patient are usually HYPERmetabolic by skin graft time (increased O2 use and CO2 production) – this increases minute ventilation
- May require high levels of PEEP to keep airways open
- May have chest wall compliance issues (decreased FRC, increased CoHgb, increased MetHgb)
What are cardiovascular anesthetic considerations in a burn patient?
- Beware of the timing since the burn and phase of fluid resuscitation (12-24 hrs post burn, pt is still losing lots of fluid and edema)
- Microvascular permeability = edema
- Water, electrolytes, proteins in the extravascular spaces
- Hypovolemic shock (burn shock) despite lots of fluids given
- Increased circulating catecholamines (increased HR and CO)
What are NMJ and relaxant anesthetic considerations in a burn patient?
- Damaged muscles due to burned tissue
- Increased nACHr density (up regulation)
- Possibly fatal increase in K+ if SUX is used
- AVOID succinylcholine in burn pts for 2 years post burn
- Non depolarizers have decreased action and require higher and more frequent dosing in burn patients
What are intraoperative anesthetic considerations for burn patients?
- Transport: sedation as needed but maintain the airway
- Anxiolytics as needed (most pts need it)
- Induction: generous opioids
- propofol, etomidate, or ketamine depending on volume status
- Maintain with agent of choice
- Emergence: long acting opioid for analgesia (they will take a lot more than you think)
What are the blood loss and replacement considerations in burn patients?
- If low H&H have blood in the OR
- Tangential excision loses 4mL/cm2 of excised skin
- Fascial excision loses 1.5mL/cm2 of excised skin
- Surgeons use vasoconstrictor solution on all excisions and skin harvest sites
- Burn surgeons are usually very reasonable about EBL and replacement
What is the purpose of the vasoconstrictor solution used in burn surgeries? What do you need to be aware of?
Either epinephrine or phenylephrine solution on all sponges
- reduces EBL from debridement sites
- reduces EBL from skin harvest sites
WILL cause peripheral vasoconstriction and increase BP
- don’t be fooled into complacency of good vitals when they should not be
- when effects of epi solution wear off, the BP drops and you have a problem
What types of burns are classified as minor burns?
<10% TBSA burn in adults
<5% TBSA burn in young or old
<2% full thickness burn
*can treat outpatient
What types of burns are classified as moderate burns?
10-20% TBSA burn in adults
5-10% TBSA burn in young or old
2-5% full thickness burn
- High voltage burn
- Suspected inhalation injury
- Circumferential burn
- Medical problem predisposing to infection
*admit to hospital
What types of burns are classified as major burns?
> 20% TBSA burn in adults
10% TBSA burn in young or old
5% full thickness burn
- High voltage injury
- Known inhalation injury
- Significant burn to face, eyes, ears, genitalia, hands, feet, or joints
- Significant associated injuries (fracture or other major trauma)
*Refer to burn center
What are the four mechanisms of burn injury?
Inhalation (beware with any fire in enclosed spaces)
Thermal (flame, steam, scald)
Electrical (beware concomitant trauma injuries)
Chemical (type, concentration, and duration)
What factors of a burn injury are indications for hospitalization and strongly suggest a burn center?
- Affects > 20% of total body surface area in adults or > 10% in children or elderly
- Full thickness burns on >5% TBSA
- Known electrical, chemical, or inhalation injury
- Significant burns to face, eyes, ears, genitalia, hands, feet, joints
- Associated injuries, pregnancy, suspected child abuse or neglect
- Comorbid conditions that will affect recovery
What are the three stages of burn injury?
- Resuscitation (0-36 hours)
- Post-Resuscitation (2-6 days) – hypermetabolism starts
- Inflammation/Infection (7 days to wound closure)
What physiologic changes do you see during the post-resuscitation hypermetabolic stage of a burn injury?
- Massive surge in catecholamines and corticosteroids (10-50x normal)
- Increased MvO2 and cardiac work (CO 150% normal)
- Persistent Tachycardia
- HTN
- Hyperventilation until wound closure
- Muscle protein degradation
- Insulin resistance
- Increased core temp
- Liver dysfunction
What renal changes are seen with burn injuries?
- Decreased GFR secondary to hypovolemia/hypotension, myoglobinuria after electrical burn, or hemoglobinuria after large body surface area burns
- Oliguria (inadequate fluid resuscitation) – diuretics shouldn’t be used to treat unless high voltage electrical burn or muscle burns
- Diuresis begins 3-5 days post burn due to increased GFR due to increased CO
- TBSA >40% result in renal tubular dysfunction and the inability to concentrate urine
