Burns- management and anesthetic considerations Flashcards Preview

Advanced Principles- Fall 2018 > Burns- management and anesthetic considerations > Flashcards

Flashcards in Burns- management and anesthetic considerations Deck (20)
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1

What are the phases seen after a burn injury?

 

What are the phases of treatment?

  • Biphasic response
    • Burn shock develops 6-8 hours after injury
    • Hypermetabolic phase develops in several days to weeks
  • Treatment in 3 phases:
    • 1) resuscitative
    • 2) debridement and grafting
    • 3) reconstructive

2

What do the different organs/systems do during the early and later phases post burn injury? (table)

CV

urinary

GI

musculoskeletal

pulmonary

endocrine

immunologic

CNS

3

Another table about the systemic response during the early phase vs the late phase.

CV

Pulm

renal

endocrine and metabolic

hepatic

hematologic

GI 

neurologic

4

What should you consider during initial airway assessment of a pt with burns?

  • Consider liklihood of inhalation injury
  • inspect the neck and oral cavity for overt issues
  • Gold standard assessment: fiberoptic bronchoscopy
    • Chest x-ray is usually normal in early phase
  • Early intubation when upper airway injury is suspected, do NOT wait for pt to decompensate

5

Who is at risk for inhalation injury?

 

  • Facial burns
  • hoarseness
  • evidence of smoke exposure
  • other classical signs of inhalation injury

6

What should you consider regarding airway management in a burn patient?

  • Intubation will be easier if not delayed
  • Awake, spontaneously breathing fiberoptic intubation if any airway abnormality is suspected
    • topical anesthesia plus hypnotic that preserves spontaneous ventilation (ketamine, dexmedetomidine)
    • use opioids and sedatives judiciously
  • If there is no airway abnormality, RSI can be used, but NO SUCC  after first 24 hours post injury
  • Severe airway burns may require immediate surgical airway/trach
  • Cuffed tubes are standard of care
  • MUST have humidification--secretions are thick and tenacious, very likely to form mucous plug

7

What is the initial management during the burn shock phase?

 

  • This is a combination of distributive, hypovolemic, and cardiogenic shock
  • Priorities: airway management and fluid resuscitation
  • Fluid losses greatest in first 12 hours and stabilize at 24 hours
  • Volume loss and edema
    • transudation of plasma proteins directly from wound bed
    • interstitial fluid shifts in unburned tissue secondary to capillary leak
  • Crystalloids are fluid of choice in 1st 24 hours

8

What can happen with over-resuscitation?

  • over-resuscitation can lead to complicationsintraabdominal hypertension- is reversible
    • >12
  • abdominal compartment syndrome- leads to organ damage
    • >20
  • pleural and pericardial effusions
  • pulmonary edema
  • fasciotomy
  • conversion of partial thickness to full thickness (think of the jackson burn zones)

 

9

What is the Parkland fluid resuscitation formula?

  • 4 ml/kg per percentage of TBSA burned in 1st 24 hours
    • half of calculated volume should be administered in first 8 hours
    • LR preferred

10

What is the hypermetabolic phase?

  • Develops over several days to weeks, changes can persist up to two years
  • Caused by immense surge in catecholamines and corticosteroids (10-50x baseline)
  • Persistent tachycardia, systemic hypertension, tachypnea, increased muscle protein degredation, insulin resistance, elevated core temp, liver dysfunction increased risk of infection
  • Can lead to physical exhaustion and death without treatment

11

What are the symptoms seen during hypermetabolic phase?

What are treatments?

  • Symptoms
    • Persistent tachycardia
    • systemic hypertension
    • tachypnea
    • increased muscle protein degredation
    • insulin resistance
    • elevated core temp
    • liver dysfunction increased risk of infection
  • Treatment:
    • early excision and grafting
    • warming strategies (burn or kept at 87-90 degrees)
    • nutritional support
    • insulin
    • beta blockers

12

How is excision (escharotomies) and grafting done?

 

  • Aggressively cut off dead tissue until they get to massive blood loss, then they lay epi soaked flaps over the bleeding area
    • Can have up to 2L blood loss in 15 minutes
  • Surgery done every 2-3 days
  • Early debridement preferred, often done in stages
    • started on 2nd day to 2nd week of unjury
  • Blood loss can be significant.

13

What are indications to suspend excision surgery?

  • 20% of BSA excised (may extend this to larger area if pt is stable)
  • time length of 2-3 hours
  • temperature drop to 35 C
  • blood loss requiring 10 units or mor PRBCs

14

What should be included in preoperative evaluation?

(9)

  • Age, weight
  • Pre-existing co-morbidities
  • review labs including acid/base
  • airway assessment, vent settings
  • TBSA burned, note inhalation injury and co-existing trauma
  • Mechanism of injury (flame, explosion, chemical, electrical, scald) and time since injury
  • Vascular access and adequacy of resuscitation (current fluid requirements, UOP, vasopressor requirements)
  • Surgical plan
  • review previous anesthetic records

15

How long should burn patients be NPO?

  • NPO after midnight is NOT appropriate for these patients!
  • Adequate caloric intake is critical
  • No need to d/c enteral feeds for intubated patient
    • unintubated patients can have feeds continue up to 4 hours before surgery
    • Once in OR, decompress NG tube/check residuals
  • Parenteral feeds should be continued intraoperatively and do not use the specific line for them
  • For procedure with unprotected airway like placing a trach, should adhere to more standard NPO guidelines

16

How should you set up pre-operatively for a burn patient?

17

What should you consider during induction of a burn patient?

  • Need all standard monitors, may need to have ekg leads stapled to pt
  • It is rare to see burn pt in first 24 hours, if you do, reduce dosage of induction agents d/t shock
  • NO SUCC AFTER FIRST 24 HOURS
  • Expect resistance to NDMB, will need higher/more frequent dosing
  • May be unable to take off vent d/t required settings, if so , use TIVA

18

What should you consider intraoperatively for a pt with burns?

(7)

  • Arterial blood pressure required if >20-30% TBSA involved
  • Accurate temperature monitoring essential/avoid hypothermia/actively warm patient and room
  • Continue ICU infusions, including narcotics and O2 during transport
  • Ensure ETT securement is infallible
    • may need to wire to teeth or screw into mandible 
  • Blood loss can be rapid and tremendous- need adequate product immediately available and checked in room
  • Anticipate use of epi-soaked gauze--may see systemic effects
  • pain control

19

Why are the effects of neuromuscular blockers different in patients who have burns?

  • Proliferation of extrajunctional nicotinic acetylcholine receptors
    • causes resistance to nondepolarizing muscle relaxants
    • increased sensitivity to depolarizing muscle relaxants (succ)
  • Succ >24 hours post injury is PROHIBITED
    • potentially lethal hyperkalemic response
    • may persist for up to 18 months post injury
  • Resistance to non-depolarizing muscle relaxants may develop within a week of burn injury
    • persist up to 1 year
    • 2-5x greater dose
    • Rocuronium in large doses up to 1.2 mg/kg can be used for RSI
    • Resistance does not prolong recovery times or alter efficacy of reversal agents

20

What should you consider with ventilator management of a burn patient?

  • Anticipate pulmonary compromise
    • RAD, laryngospasm, bronchospasm, ventilation-perfusion mismatch, decrease in pulmonary compliance , PNA, ALI, ARDS
  • may need high FiO2 and frequent suctioning
  • Lung protective ventilation
    • target TV 4-8 ml/kg
    • plateau pressure = 30 cm H2O
    • permissive hypercapnia up to pH of 7.2
  • HFOV- may require TIVA