Burns Lecture for 2nd Year MBBS Students
1. Definition and Classification of Severe Burns
Severe burns encompass both life-threatening and function-threatening injuries that require specialized multidisciplinary management. 1
Criteria for Severe Burns in Adults:
- TBSA burned > 20% 1
- Deep burns > 5% 1
- Presence of smoke inhalation 1
- Deep burns in function-sensitive areas (face, hands, feet, perineum) 1
- Burns from high-voltage electricity 1
Additional criteria when TBSA < 20%:
- Age > 75 years 1
- Severe comorbidities 1
- Deep circular burns 1
- TBSA > 10% 1
- Deep burn 3-5% 1
- Low-voltage electrical or chemical burns (e.g., hydrofluoric acid) 1
Criteria for Severe Burns in Children:
- TBSA > 10% 1
- Deep burns > 5% 1
- Infants < 1 year of age 1
- Severe comorbidities 1
- Smoke inhalation injuries 1
- Deep burns in function-sensitive areas (face, hands, feet, perineum, flexure lines) 1
- Circular burns 1
- Electrical or chemical burns 1
2. Assessment of Burn Surface Area
The Lund-Browder chart is the gold standard for measuring TBSA in both adults and children, as it is the most accurate method. 1, 2
Key Assessment Points:
- TBSA is overestimated in 70-94% of cases, leading to excessive fluid administration 1, 2
- The Wallace rule of nines significantly overestimates TBSA and is not suitable for children 1
- The patient's palm and fingers (open hand) equals approximately 1% TBSA - useful for quick field estimation 1, 2
- Serial halving method can be used in prehospital settings or mass casualty situations 1
- Smartphone applications (e.g., E-Burn) can facilitate accurate assessment 1
- Repeated evaluation of TBSA during initial management prevents overtriage (wasting resources) and undertriage (increasing morbidity and mortality) 1
3. Pathophysiology and Complications
Burns induce a state of immunosuppression that predisposes patients to infectious complications, with most deaths in severely burned patients due to burn wound sepsis or inhalation injury complications. 3
Major Acute Phase Complications:
- Hypovolemic shock due to inflammation, capillary leak syndrome, and microcirculation alterations 2
- Haemodynamic failure 1
- Respiratory failure 1
- Hypothermia 1
- Compartment syndrome requiring escharotomy 1, 2
Infectious Complications:
- Burn wound sepsis remains the leading cause of death 3
- Pneumonia 3
- Catheter-related infections 3
- Suppurative thrombophlebitis 3
4. Initial Management in First 24 Hours
Consult a burn specialist urgently, ideally through telemedicine, to determine severity, measure TBSA, initiate appropriate fluid resuscitation, and ensure proper referral. 1, 2
Immediate Actions:
- Control shock and pain as prime importance 4
- Cleanse and debride burn wounds 4
- Clean wounds with tap water, isotonic saline, or antiseptic solution 2
- Establish IV access in unburned areas when possible; consider intraosseous access if IV cannot be rapidly obtained 2
Fluid Resuscitation:
- For adults with burns >15% TBSA and children with burns >10% TBSA: administer 20 mL/kg of balanced crystalloid solution (preferably Ringer's Lactate) within the first hour 2
- Monitor for signs of hypovolemic shock 2
- Avoid fluid overloading - remember that TBSA is frequently overestimated 1, 2
Wound Care:
- Consider whether blisters should be flattened or excised (ideally with burn specialist consultation) 2
- Apply appropriate dressings based on burn depth, TBSA, wound appearance, and patient's general condition 2
- Prevent bandages from causing tourniquet effect 2
- Monitor distal perfusion regularly when circular dressings are applied 2
- Provide adequate analgesia before wound cleaning and dressing application 2
5. Referral Criteria to Burn Centers
If there is an indication for admission to a burns centre, the patient should be admitted directly to the centre rather than through secondary transfer. 1
Benefits of Specialized Care:
- Multidisciplinary approach is associated with better survival, facilitates rehabilitation, and reduces complications, length of hospital stay, and costs 1
- Early excision of eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis 3
When to Seek Specialist Opinion:
- First responders should urgently request specialist opinion to help determine severity, measure TBSA, initiate appropriate fluid resuscitation, and ensure appropriate management 1
- Telemedicine should be used to improve initial assessment of severely burned patients 1
6. Topical Therapy
Silver Sulfadiazine 1% Cream:
- Apply once to twice daily to a thickness of approximately one-sixteenth of an inch 4
- Burn areas should be covered at all times 4
- Reapply immediately after hydrotherapy 4
- Continue treatment until satisfactory healing has occurred or until the burn site is ready for grafting 4
- Dressings are not required but may be used if individual patient requirements necessitate 4
- Caveat: Prolonged use on superficial burns may delay healing 2
Mafenide Acetate:
- Inhibits carbonic anhydrase, which may result in metabolic acidosis, usually compensated by hyperventilation 5
- Close monitoring of acid-base balance is necessary, particularly in patients with extensive second-degree burns and those with pulmonary or renal dysfunction 5
- Use with caution in burn patients with acute renal failure 5
- Fungal colonization may occur concomitantly with reduction of bacterial growth 5
7. Escharotomy
Escharotomy should be performed if a deep burn induces compartment syndrome in the limbs or trunk that compromises airways, respiration, and/or circulation. 1, 2
Critical Points:
- Ideally performed in a burns centre by an experienced provider 1
- Carries risks of complications, particularly hemorrhage and infection 2
- Should be performed only at a Burns Centre or after specialist advice if transfer is impossible 2
- Required within 48 hours of injury in some cases 1
8. Special Considerations for Electrical Burns
Electrical burn injuries require close cardiac monitoring due to the risk of cardiac arrhythmias, which are a primary cause of immediate death from electrocution. 6
Key Management Points:
- Ensure scene safety by turning off the power source before approaching the victim 6
- Assess for need of CPR, defibrillation, and treatment for shock and thermal burns 6
- Cardiac arrhythmias including ventricular fibrillation, ventricular asystole, and ventricular tachycardia may result from both low and high-voltage current 6
- Early intubation should be considered for patients with evidence of extensive burns, particularly involving face, mouth, or anterior neck 6
- Rapid IV fluid administration is indicated for victims with significant tissue destruction 6
- Severity often does not correlate with visible skin damage - do not underestimate based on external appearance 6
- Initiate therapy with crystalloid isotonic fluids (0.9% saline solution) as first line for patients showing signs of shock 6
9. Common Pitfalls to Avoid
These errors significantly increase morbidity and mortality in burn patients:
- Overestimating TBSA (occurs in 70-94% of cases), leading to excessive fluid administration 1, 2
- Delaying specialist consultation, which increases morbidity and mortality 2
- Improper dressing application that restricts circulation 2
- Routine use of systemic antibiotics for prophylaxis 2
- Prolonged use of silver sulfadiazine on superficial burns, which may delay healing 2
- Performing escharotomy without proper training or consultation 2
- Prolonged use of external cooling devices, which can cause hypothermia 2
- Underestimating electrical injury severity based on visible skin damage 6
- Failure to monitor cardiac function in electrical burns, missing potentially fatal arrhythmias 6
10. Historical Context and Modern Advances
Most major advances in burn care occurred in the last 50 years, spurred by wars and great fires. 7
Key Historical Developments:
- Use of systemic antibiotics and topical silver therapy greatly reduced sepsis-related mortality 7
- Antiseptic surgical techniques, burn depth classification, and skin grafting allowed excision and coverage of full-thickness burns, greatly improving survival rates 7
- Advancements in methods of assessing burn surface area paved way for more accurate fluid resuscitation 7
- Introduction of metabolic care, nutritional support, and care of inhalational injuries further improved outcomes 7
- Improved outcomes attributed to advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices 3
- Introduction of silver-impregnated devices (e.g., central lines and Foley catheters) may reduce incidence of nosocomial infections 3