Anesthesia Implications for Burns - Exam 1 Flashcards
What are the 5 types of burn injury/damage to skin or tissue?
- Heat
- Electrical
- Friction
- Chemical
- Radiation
Heat Burns
What 3 things are the depth of the thermal injury r/t?
- contact temperature (very cold/hot)
- Duration of contact
- Thickness of skin
Heat Burns
What are the “thin skin areas of the body”?
- joints
- hands
- face
- genitals
Heat Burns
The ____ ____ ____ determines the extent of the damage to the patient.
Except in what 2 special circumstances?
- depth of injury
- trapped in a fire - toxic exposure
- electrical burns
Heat Burns usually involve the ____ and ____.
- epidermis & dermis
can involve muscle/bone
What are the 4 most common examples of Heat Burns?
- Flame
- Hot liquid
- Hot solid
- Steam
5Ts of heat burn risks: LOL.
- Testoterone
- Tequila
- Tattoos
- Tooth:Tattoo Ratio
- Teeth
In electrical burns, ____ ____ is transformed to ____ as current passes through body tissues
- electrical energy
- heat
- basically the body is turned into a conduction pathway
- membrane potential disrupted
Electrical burns
What 3 things does the magnitude of the electrical burn depend on?
- pathway of current
- resistance to current flow
- strength and duration of current flow
Electrical Burns
Is DC or AC worse?
- DC worse - stays into contact w/ source longer
- most houses have AC
How do electrical burns often happen?
- lightning
- line men - high tension
- POC: head/arm
- POG: the feet/ground
- travels through whole body
What cardiac dysrhythmia do electrical burn pts commonly present with?
Tx:
- V-fib
- quick defibrillation
Friction burns are a combo of ________ disruption & ____ generated by friction.
Ex:
- mechanical disruption
- heat
- ex: rope around arms/legs
Chemical Burns
What 3 caustic reactions happen with chemical burns?
- pH alteration d/o compound
- widespread cellular disruption = electrolyte disruption
- direct toxic effect on metabolic process
What types of chemicals cause chemical burns?
- liquids/powders
- aerosol
Chemical Burns
What 2 things are the magnitude of chemical burns related to?
- Duration of exposure - decontamination
- Nature of the agent (acid/base)
Chemical Burns
aCids cause necrosis by:
Coagulation
Chemical Burns
Alkali cause necrosis by:
Liquefacation
________ causes damage w/ radiation burns.
- ionization
Radiation burns
what 2 things does the magnitude depend on?
- dose and time of exposure
- type of particles
Radiation Burns
What are 4 common examples?
- sunburns
- therapeutic radiation
- diagnostic procedures (cataracts, neuropathy exposure risk)
- nuclear industry workers
How long does it take for burns to declare themselves?
24-72 hours
* may progress from 2nd degree - 3rd degree
Are burns usually uniform in depth?
Where is the most concentrated damage usually?
- not uniform in depth (mix of superifcial and deep)
- center of exposure = inreased concentrated damage
What degree of burns are included in the TBSA % calculation?
- 2nd and 3rd degree
Classification of Burn Depth
Why do kids < 5 have deeper burns?
- thinner skin (more adipose tissue)
- leads to deeper burns
Classification of burn depth
Why do adults >55 have deeper burns?
- less tissue there to disrupt the thermal effects
- thinner skin - less adipose tissue
Classification of Burn Depth
Characteristics of Superficial (1st degree burn):
- epidermis only
- skin intact, red
- dry skin, no blisters
- painful & hypersensitive (extreme temps cause pain)
- heal time: 3-6 days
Classifications of Burn Depth
Characteristics of Superficial Partial Thickness (2nd degree burn)
- epidermis & part of dermis
- mottled, red
- blisters/weeping
- very painful - exposed nerve endings
- Heal time: 10-14 days
- minimal scarring
Classifications of Burn Depth
Characteristics of Deep Partial Thickness (2nd degree burn)
- extends deeply into dermis
- decreased moisture (sweat glands destroyed)
- pale color
- absent/prolonged blanching
- less painful - nerve endings damaged
- Heal time: 21-28 days
- requires skin grafting
Classifications of Burn Depth
Characteristics of Full Thickness (3rd degree) burns:
- dermis is destroyed
- translucent, dry, painless, charred
- non-blanching (decreased perfusion)
- requires grafting/amputation
Rule of 9s
Head (adult)
9%
Rule of 9s (adult)
Each arm
9%
* 4.5% anterior
* 4.5% posterior
Rule of 9s (adult)
Each leg
18%
* 9% anterior
* 9% posterior
Rule of 9s (adult)
Ant/Post Trunk
36%
* 18% Anterior
* 18% Posterior
Rule of 9s (adult)
Perineum
1%
Rule of 9s (infant)
Head/Neck:
Abdomen:
Each arm:
Each leg:
Back:
Buttocks:
Genital Area:
- head/neck: 21%
- Abdomen: 13%
- Each arm: 10%
- Each leg: 13.5%
- Back: 13%
- Buttocks: 5%
- Genital Area: 1%
head % larger b/c disproportionate to body
Estimation of TBSA
How accurate is the Rule of 9s?
- 60-70% accurate - various depths
Estimation of TBSA %
Palmer method -
- useful for irregular areas
- patients palm w/ fingers together
- 1% per palm
Estimation of Burn TBSA%
Inaccuracies
larger burn SA:
women w/ large breasts:
obese:
- larger burn SA: underestimated - longer to declare
- large breasts: larger SA compared to other areas
- Obese: underestimate torso, overestimate extremity
Pathophysiology of Burns
What are the 2 conflicting priorities happening?
- shock & edema
- d/o where they are in the burn process
Pathophys burns
early on: (hypovolemia)
- hypovolemic shock & decreased perfusion
- plasma loss from microvasculature into interstitium (increased permeability)
- relative hypovolemia
pathophys burns
Edematous state:
- pt becomes edematous from loss of plasma into interstitium
- fluid load & edematous/volume depletion intravascularly
Pathophys of burns
What is fluid loss a funtion of?
- burn size
- pt weight
- type of burn
- visible burn SA may not be directly r/t extent of burn (inhalation - Lung SA tennis court)
Pathophys of Burns
Patients w/ what TBSA develop burn shock and need IV resuscitation in ICU?
> 20% TBSA
Pathophys of burns
What does under resuscitation lead to?
decreased intravascular vol.
* decreased perfusion
* burn shock
* end organ failure (kidneys susceptible)
Pathophys of burns
What does over resuscitation lead to?
- abdominal compartment syndrome (mesenteric edema, esp. crystalloid)
- pulmonary edema
- ARDS
What is the generic metabolic response in burns?
Auto-cannibalism - hypermetabolic
What 6 things does Autocannablism lead to?
- loss of fat
- loss of lean body mass (proteolysis)
- gluconeogenesis (lose glucose)
- lipolysis
- hypermetabolism
- insulin resistance
What 2 things make the intensity & duration of auto-cannabilism (hypermetabolic state) worse?
- the magnitude of the injury
- degree of pain
Autocannabilsm
How long can cannibalism last?
What do we need to ensure in these pts?
- metabolic rate doubles in 40% TBSA - can last for 3-6 months or longer
- meeting nutritional needs
- continue tube feeds, clear carb liquids 2hrs pre-op, TPN!
Burn Metabolism
What happens w/ carbohydrate metabolism?
- increases in cortisol, catecholamines, and glucagon
- accelerated hepatic gluconeogenesis
- peripheral insulin resistance
Burn metabolism - carbs
What causes peripheral insulin resistance? What is it related to? How long can it last?
what can we do for them?
- post-receptor defect hindering the uptake of insulin & impaired intracellular glucose transport
- r/t extent of burn
- can last 3 yrs (3-6mos common)
- keep an eye on glucose levels & be mindful of carb status
Burn Metabolism
What happens w/ lipid metabolism?
- accelerated lipolysis
Burn Metabolism
What causes accelerated lipolysis associated w/ burn injuries?
- B2 and B2 adrenergic stimulation - increased cAMP
- elevated glucagon, TNF, IL
- elevated levels of FFA.. produce ATP
Burn metabolism
What is the Tx for accelerated lipolysis?
- daily dose of BB
- they will struggle more w/ BP
- MOA: decreases lipid oxidation & metabolic rate
Burn Metabolism
What happens with protein metabolism?
- accelerated proteolysis of skeletal muscle
- provides substrate for hepatic gluconeogenesis
Burn Metabolism
What is the degree of protein loss proportional to?
- degree of stress
- doubled in severe burns
Burn Metabolism
What is the treatment for proteolysis/what can improve it?
What makes it worse?
- encourage early PT
- caution w/ positioning in OR
- improved by cortisol (anti-inflammatory)
- TNF, IL-1, IL-6 (inflammatory mediators - cytokines)
Initial Stabilization of Burns
When should we intubate the patient?
- prophylactically
- airway soft tissues swell overtime & edema gets worse
Initial Stabilization of Burns
When is fluid resuscitation most important?
- early on
- communicate w/ primary team to determine pt. specific goals
Initial Stabilization of Burns
CV stabilization - what does the increased catecholamine surge lead to?
- increased HR
- increased metabolic demand & metabolism
- problematic for elderly w/ comorbidities
Secondary Priorities for Burn Pts
What are the pain control methods in initial and long-term management?
- initial: IV
- long-term: nerve blocks, SR options (methadone, oxycodone), NSAIDs, PCA, IV ketamine (procedural)
- supplement w/ anxiolytics
Secondary Priorties for Burn Pts
Why are burn pts @ increased risk of DVT?
- fluid shifts
- thromboprophylaxis important
Secondary Priorities for Burn Pts
What are the concerns w/ wound closure and burn patients?
- multiple OR trips
- fluid/blood loss!
Secondary Priorities of Burn Pts
What do we need to ensure for pts nutrition and hypermetabolic state?
- ensure adequate nutrition
- control hypermetabolic state w/ BB, early PT, glucose control
Secondary Priorities of Burn Pts
How can we help prevent infections in burn injuries?
- keep warm
- keep hemostatic
- maintain normal glucose
- minimal indications for Abx early on
Secondary Priorities for Burn Pts
What pts do we need to use caution in fluid resuscitation?
- CHI - fluids/head injury can kill them
Secondary Priorties for Burn Pts
What are the concerns w/ spinal injuries and burns?
- they may need for fluids than just a burn pt
- the spinal injury causes peripheral vasodilation = compounding factors
- use vasopressors as well!
What are the 2 possible PK/PD alterations in burn pts?
- May need less doses/drugs to avoid toxicity
- May need more dose/drugs b/c of the hypermetabolic state causing decreased efficacy
Causes of Intravascular Vol Loss in Burns
- Impaired ________ ________.
- Increased ________ ________.
- Loss of intravascular ________ ________.
What else causes dilation of vessels in burns?
- impaired endothelial barrier
- increased capillary permeability
- loss of intravascular oncotic pressure
systemic inflammatory reactions - histamine, PG, cytokines
Fluid Resuscitation
What is the Parkland Formula?
starts at time of injury
* 4 ml/kg/%TBSA (1st 24 hrs)
* 2mL/kg/%TBSA in 1st 8 hrs
* 2mL/kg/%TBSA in next 16 hrs
Fluid Resuscitation - Parkland
What types of burn injury may need higher volumes?
- inhalation
- electrical
- delayed initial resuscitation
Fluid Resuscitation
What is the US Army ISR Rule of 10 (adult)?
- 10mL/hr x TBSA
- > 80kg = add 100mL/10kg over 80kg
Fluid Resuscitation
What is the US Army ISR Rule of 10 (pedi)?
- 3 x TBSA x kg = vol. for 1st 24 hrs
- 1/2 total vol. over 8 hrs
What are the 5 criteria for need to transfer to a burn center?
- Full thickness > 10% BSA
- high voltage electrical burns
- chemical burns
- associated inhalation injury
- face, hands, feet, perineum, major joints
Fluid Resuscitation
How long are the formulas good for?
Who may they not be appropriate for?
- good for 1st 24 hrs
- not good for pts w/ comorbidities or non-responders to fluid
Fluid needs
What types of fluids do we use?
What is a risk w/ high saline amount?
- crystalloid (LR/isotonic)
- saline - hypernatremic hyperchloremic metabolic acidosis
- no boluses w/ crystalloid
Fluid Needs
How are crystalloids/fluids titrated?
- every hour according to UOP goal
- 30-50mL/hr or 1mL/kg/hr
- titrate 20-25% up or down
At what amount of fluid administration do we start to see fluid overload symptoms?
What are the symptoms?
- 1500mL/hr or 250mL/kg in 24hrs
- ACS, pulmonary edema
Fluid Needs
At what weight do we use the adult formula for fluids?
What is the formula for kids <14kg and <40kg?
What do we need to add for kids <20kg?
What is the UO goal for pedi?
- > 40kg use adult formula
- 2-4mL x kg x % TBSA (2nd and 3rd)
- maintenance of D5LR for <20kg
- 0.5-1mL/kg/hr
Fluid Status in Burns
When should we start colloid infusions?
What is the DOC?
- 8-12 hrs post burn if >1500mL/hr
or - projected 24 hr total volume >250mL/kg in 24 hrs
use albumin 5%
Fluid Status
What is the pedi albumin rate?
What do we need to reduce?
- 4-7mL/kg
- rate: 0.5mL/min
- reduce maintenance isotonic crystalloid by equal volume per hour
Cardiac Status
What happens in the hypodynamic “ebb” state?
- CO low (reduced by 60% of baseline)
- relative hypovolemia
- reduced response to catecholamines
- increased SVR d/t vasopressin levels
- myocardial ischemia (decreased coronary flow)
- very risky period for someone w/ cardiac disease
Cardiac Status
What happens in the “hyperdynamic state”?
- increased CO, tachycardia
- increased myocardial O2 consumption = myocardial ischemia
- decreased SVR
- give BB
Pulmonary Status
What leads to pulmonary HTN/edema?
systemic inflammatory processes
* pulmonary capillary alveolar membrane disruption
* decreased plasma oncotic pressure
* extravascular lung water - impairs gas exchange
* bronchospasm common
Pulmonary Status
What can be used to maintain pulmonary integrity in intubated burn pts?
What is the tx for bronchospasm?
- PEEP
- scheduled bronchodilator therapy - give before induction esp. if instrumenting airway
Pulmonary Status
What restrictive lung defects happen with burn injuries?
- impaired ventilation from circumferential burns/scars
- monitor airway pressure
- pt will get relative hypoxia/hypercarbia
- intra-op escharotomy
What are the symptoms of inhalation injury?
- singeing of face/nasal hairs, black soot in mouth
- oropharyngeal carbon
- Carboxyhemoglobin levels >10%
- wheezing
- confirm w/ bronch
What are the main concerns for facial burns?
- management of devices difficult
- umbilical ties for ETT securement
- remove contacts
- optho consult: globe/corneal injury
Facial Burns
Where is bacitracin applied?
Where is erythromycin applied?
What is NOT applied to the face?
- baci - eyelids
- erythro - eyes
- no silvadene
Symptoms of CO poisoning:
- HA, nausea, seizing, ARF, myocardial ischemia/depression
Treatment for CO:
100% O2
caused by fuels
Treatment for CN:
- cyanokit
- B12 (cyanocobalamin)
caused by plastics
What are the nutrition concerns after burn injuries? (elevated….)
What can we do to meet their needs?
- elevated protein, vitamin, energy needs
- insulin resistance
- tube feeds to jejunum (decreased asp. risk)
What are the main 3 causes of PK/PD changes in burn pts?
- changes in plasma protein concentration (albumin) = increased free fraction and Vd
- Alterations in drug receptors (nAch)
- CO changes (ebb/flow)
What happens w/ burn pts and nAch R’s?
- upregulation of receptors (increased # and sensitivity)
- resistant to non-depolarizers (>25% TBSA)
- sensitive to depolarizers (after 24-72hrs)
Intra-op care of Burns
Monitoring Standards
* EKG:
* pulse-ox:
* BP cuffs:
* ABG:
* UOP:
- EKG: stapled, alligator clips
- pulse-ox: accuracy w/ COHb? edema/weeping interference
- BP cuffs: inaccuracy from edema
- ABG: Base Deficit alternative to lactate, used for oxygenation
- UOP: watch trends!
Intra-op Care of Burns: monitoring
What temperature changes happen?
What interventions can we provide?
- loss of up to 1 degree C every 15 min b/c loss of skin integrity
- warm IVF, warm OR, convection warming devices
Intra-op Care of Burns
What are 5 indications of inhalation injury?
What do these necessitate?
- Hoarseness, wheezing, SOB
- carbonaceous sputum
- singed nasal & facial hair
- comatose pt
- > 40% TBSA
early intubation
Intra-op Care of Burns: Airway
What are signs of impending airway obstruction?
- stridor
- hoarseness
- dysphagia
Intra-op Care of Burns: Airway
What makes laryngoscopy difficult?
What makes BVM ventilation difficult?
laryngoscopy:
* edema (inhalation)
* limited mobility: pain, contractures, eschar
BVM ventilation:
* burn dressings prevent adequate seal
consider awake intubation = sedate/topicalize airway
Intra-op Care of Burns: Airway
What size ETT is preferred for intubation and why?
- 8 or largest size possible
- facilitates subsequent bronchoscopy & pulmonary toilet
- decreases risk of occlusion from casts (blood, mucous, debris)
Intra-op Care of Burns: Airway
What are 2 ways the ETT can be secured?
- cotton umbilical tape
- wire to teeth
- no LMAs - only a back up
Intra-op Care of Burns: Airway
Induction
* when to use prop:
* when to use ketamine:
* concerns w/ etomidate:
* opioids:
- prop: hyperdynamic state
- ketamine: hypodynamic state - stimulates SNS
- etomidate: adrenal insufficiency concern, supplement w/ steroids
- opioids: maintain hemodynamic stability but tx pain!
Intra-Op Care of Burns
What causes hemodynamic instability?
What 2 things can we do in the OR?
- hypovolemia (decreased preload & CO)
- Resuce TEE
- R/O cardiogenic or distributive shock, MI
intra-Op Care of Burns: Blood Transfusions
How much blood volume can be lost?
When do we transfuse? ACS?
- 2.6% total blood volume lost for every 1% burn excised or autograft harvested
- transfuse: keep Hgb 7-8g/dL
- ACS: Hgb 10g/dL
Intra-Op Care of Burns:
What MAP diagnoses burn shock?
- <55mmHg depsite fluid resuscitation
Intra-Op Care of Burns: Blood Trasfusions
How can we provide hemostasis in these pts?
- topical thrombin
- staged procedures - mult. OR trips
- subQ vasoconstrictors (bad for graft take!)
- rFVII & TXA = thrombosis risk
Intra-Op Care of Burns:
What is the shock treatment?
Vasopressors
* Vasopressin
* Norepinephrine
* CVP: only useful for trends (6-8mmHg)
Intra-Op Care of Burns
What is Tumescent LA used for?
- used for taking the skin graft
- infiltrated into subQ tissue
effects
* decreased blood loss
* easy excision of granulation tissue
* shorter surgical times
* no hematoma or bruising post-op
Intra-Op Care of Burns
What is the Tumescent LA dose?
- Lidocaine 1g w/ epi + 10mEq NaHCO3/1000mL NaCl
55mg/kg max
Intra-op Care of Burns
What is the target PCO2 and pH?
- PCO2: 30-35mmHg
- pH: >7.20
Intra-Op Care of Burns
Why do we give intubated patients nebulized Heparin/Albuterol?
How often?
- pts w/ inhalation have ulceration/sloughing of airways
- Heparin prevents clumping of the epithelial cells
- Albuterol: Heparin can cause bronchospasm
give q4h
Intra-Op Care of Burns
What happens with ACS?
What is the mortality rate of an open abdomen?
What are the bladder pressures associated w/ ACS?
- abdominal pressure displaces diaphragm up by bowel edema
- 90% mortality
- > 12mmHg = early intra-abd. HTN; >20mmHg = ACS
Post-op Care of Burns
Why do we leave pts intubated post-op?
- inhalation burn s
- @ risk of continued bleeding
- additional surgery plans
- need to minimize movement/graft disruption
Post-Op Care of Burns
What other modalities need to be provided to burn pts?
- DVT prophylaxis
- BB admin
- nutritional support
- temp control
Post-op Care of Burns
What pain treatment options do we provide to burn pts?
- long-acting meds
- scheduled anxiolytics
- IV, enteral, transmucosal, PO
- additives PRN for burn care/dressing changes
- NO 50/50
- peripheral nerve blocks
Post-Op Care of Burns
What special care is needed r/t extremities?
- elevate 30-45 degrees (pillows, slings)
- examine pulses hourly
When are escharotomies performed?
- loss of perfusion to extremities
- ventilator compromise/decreased CO
Adjuncts to Burn Resuscitation:
- GI prophylaxis
- Sew/staple venous and arterial lines
- insert foley immediately - maintain urethral patency
- tetanus
- IV Abx/steroids not indicated!
Burn dressings
* topical Abx:
* other dressings:
* skin substitutes:
* silvadene:
- silvadene & sulfamylon
- silver dressings, silverton water or saline q8hrs, silver nitrate
- biobrane
- NO SILVADENE TO FACE!!!