Burn, part 4 (Schwartz) Flashcards
Mortality rates in patients with inhalational injury
25%: inhalational injury
50%: inhalational injury + TBSA ≥20%
66%: inhalational injury + ARDS
100%: inhalational injury + ARDS + TBSA ≥60%
2 ways smoke inhalation causes injury
- direct heat injury to the upper airways
- inhalation of combustion products into the lower airways
- decreased lung compliance
- increased airway resistance
Upper airway injury
Maximal airway edema in the first 24 to 48 hours after injury that often requires a short course of endotracheal intubation for airway protection
Used in grading inhalation injury
Abbreviated Injury Score
0 - no injury
4 - massive injury
Best tools for diagnosing inhalation injury
Clinical presentation and bronchoscopic evaluation
Treatment of inhalation injury
Primarily supportive care
1. Aggressive pulmonary toilet
2. Routine use of nebulized bronchodilators
3. Nebulized N-acetylcysteine (antioxidant free radical scavenger)
4. Aerosolized heparin
The use of steroids has traditionally been avoided due to worse outcomes in burn patients.
MOA of carbon monoxide (CO) poisoning
- Affinity for hemoglobin is 200-250 x more than that of oxygen –> anoxia and death
- Uncoupling of oxidative phosphorylation in mitochondria
- free radical generation
- increased systemic inflammatory response via platelet activation
Management of CO poisoning
Administration of 100% normobaric oxygen
- gold standard
- reduces the half-life of CO from 250 minutes in RA to 40-60 minutes
MOA of cyanide toxicity
- Inhibition of cytochrome oxidase, and consequently oxidative phosphorylation
Presentation of cyanide toxicity
- Pesistent and severe lactic acidosis
- neurologic symptoms
- pulmonary edema
- cardiac sequelae (STE on ECG)
- Biiter almond breath (rare)
- Cherry red skin (rare)
Treatment of cyanide toxicity
- 100% oxygen
- Hydroxocobalamin
- Sodium thioosulfate
Remarks on hydroxocobalamin
- Quickly complexes with cyanide
- Recommended for immediate therapy
- Given the unknown side-effects of hydroxocobalamin, it should be reserved only for patietns with a strong suspicion of cyanide poisoning
Remarks on sodium thiosulfate
- Slow; not effective for acute therapy
- In the majority of patients, lactic acidosis will resolve with ventilation, and sodium thiosulfate treatment becomes unnecessary
remarks on ARDS
- Treatments have improved so that mortality is primarily from multisystem organ failure rather than isolated respiratory causes
- The ARDS Network Study finding that low tidal volume (6 mL/kg) or “lung-protective ventilation” had 22% lower mortality than patients with traditional tidal volumes of 12cc/kg
Topical therapies for burn wound
- Silver sulfadiazine
- Mafenide acetate
- Silver nitrate
- Dakin’s solution
- Bacitracin, neomycin, polymyxin B
- Mupirocin
Remarks on silver sulfadiazine
- Primarily as prophylaxis against burn wound infection
- inexpensive, easily applied, and with soothing qualities
- Neutropenia?
- Destroys skin grafts and is contraindicated on burn or donor sites in proximity to newly grafted areas
- May retard epithelial migration in healing partial-thickness wounds
Remarks on mafenide acetate
- both for treating and preventing wound infections
- Excellent antimicrobial for fresh skin grafts
- effective even in the presence of eschar
- Metabolic acidosis? (carbonic anhydrase inhibitor; not significant based on studies)
Remarks on silver nitrate
- solution used must be dilute (0.5%)
- prolonged application leads to electrolyte extravasation with resulting hyponatremia
- rare complication: methemoglobineam
- black stains (laundry costs may offset any fiscal benefit to the hospital)
Remarks on Dakin’s solution
0.5% sodium hypochlorite solution
Acceptable alternative as an inexpensive topical antibicrobial
For smaller burns, this can be used
Triple antibiotic ointment (bacitracin, neomycin, polymyxin B)
- may also be used for larger burns that are nearly healed
- also useful for superficial partial-thickness facial burns as they can be applied and left open to air without dressing coverage
