Burns in ICU

Quick Answer

Burns in ICU require systematic assessment of total body surface area (TBSA) and burn depth, aggressive fluid resuscitation (Parkland formula), airway protection for inhalation injury, and early wound management (escharotomy, excision and grafting). Key priorities: establish airway, initiate Parkland resuscitation (4 mL × TBSA% × kg over 24h with half in first 8h), monitor for compartment syndrome, and plan for early excision (day 0-2 improves outcomes).

CICM Exam Focus

Viva Topics:

• Burn depth assessment (superficial, partial-thickness, full-thickness)
• TBSA calculation methods (Rule of Nines, Lund-Browder, palm method)
• Parkland formula fluid resuscitation and endpoints
• Inhalation injury recognition and management
• Escharotomy indications and technique
• Early excision timing and outcomes
• Electrolyte abnormalities in burns

SAQ Themes:

• Fluid resuscitation calculation and monitoring
• Inhalation injury and airway management
• Burn depth assessment and management plan
• Escharotomy indications and technique
• Electrolyte abnormalities (hypokalaemia, hypomagnesaemia, hypophosphataemia)

Key Points

• TBSA Assessment: Rule of Nines (adults) or Lund-Browder chart (paediatrics) - palm method (1%) for scattered burns
• Parkland Formula: 4 mL × TBSA% × kg over 24h, half in first 8h (adjust to urine output 0.5-1.0 mL/kg/hr)
• Burn Depth: Superficial (epidermis, red, painful), partial-thickness (dermis, blisters, white/red, painful), full-thickness (through dermis, white/charred, painless)
• Fluid Resuscitation: Lactated Ringers preferred, crystalloid only first 24h, add colloids after 24h for ongoing needs
• Inhalation Injury: Suspect if enclosed space, facial burns, soot in airway, stridor, hoarseness, hypoxia - diagnose with bronchoscopy
• Escharotomy: Indicated for circumferential chest burns (restricts ventilation), limb burns (compartment syndrome) - relieve within 6h of burn
• Early Excision: Day 0-2 vs day 14 improves mortality, reduces infection, shortens hospital stay
• Electrolytes: Hypokalaemia (peak day 2-3), hypomagnesaemia (peak day 2-3), hypophosphataemia (peak day 2-3), hypermetabolism

Clinical Overview

Burn injuries represent a complex physiologic insult requiring specialised intensive care management. Severe burns (greater than 20% TBSA in adults, greater than 15% in children) trigger profound systemic inflammation, capillary leak, and hypermetabolic response. ICU management focuses on:

1. Airway protection (inhalation injury risk)
2. Fluid resuscitation (capillary leak, hypovolaemia)
3. Wound management (infection control, excision)
4. Metabolic support (hypermetabolism, catabolism)
5. Complication prevention (sepsis, ARDS, compartment syndrome)

The burn mortality equation (e.g., Baux score: age + TBSA% + inhalation injury [17 if present]) provides prognostication and guides triage to specialised burn centres.

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Epidemiology

Incidence

• Global: ~11 million burns annually requiring medical attention, 180,000 deaths per year
• Australia: 5,000-6,000 hospital admissions/year, 50-100 deaths/year
• ICU Admission: 10-15% of burn patients, greater than 20% TBSA or inhalation injury
• Paediatric: 40% of burn patients, scalds most common (60%)
• Mortality: Overall 2-3%, ICU 20-40%, increases with age and TBSA

Risk Factors

• Age: Extremes of age (below 5 or greater than 65 years) have higher mortality
• TBSA: Mortality increases exponentially with TBSA
• Inhalation Injury: Doubles mortality risk, independent of TBSA
• Comorbidities: Diabetes, cardiovascular disease, COPD increase risk
• Socioeconomic: Lower SES, rural/remote locations, limited access to care

Mechanisms

• Thermal: Flame (45%), scald (35%), contact (10%), flash (5%)
• Chemical: Acids, alkalis, industrial agents
• Electrical: High-voltage (greater than 1000V), low-voltage (below 1000V), lightning
• Radiation: Sunburn, radiation therapy, occupational exposure

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Pathophysiology

Local Burn Response

Zone of Coagulation: Irreversible tissue necrosis at the burn centre, no viable cells. Requires excision and grafting.

Zone of Stasis: Surrounding the necrotic zone, compromised perfusion due to microvascular thrombosis and edema. Viable if resuscitated promptly, progresses to necrosis if untreated. Primary target for early resuscitation.

Zone of Hyperaemia: Outermost zone with increased blood flow, minimal injury, typically recovers spontaneously.

Systemic Response

Capillary Leak: Thermal injury triggers inflammatory mediators (histamine, bradykinin, prostaglandins, ROS) causing endothelial damage and increased permeability. Maximal at 12-24h, resolves by 48-72h. Leads to:

• Intravascular volume depletion (third-spacing)
• Tissue edema (airway, limbs, compartments)
• Hypoalbuminaemia (capillary leak)
• Haemoconcentration (elevated Hct)

Hypermetabolic Response: Maximal at 7-10 days, persists up to 2 years. Characterised by:

• Increased REE (up to 2× basal)
• Catabolism (muscle breakdown, protein loss)
• Insulin resistance (hyperglycaemia)
• Lipolysis (increased free fatty acids)
• Elevation of catecholamines, cortisol, glucagon

Immunosuppression: Burns induce both systemic inflammatory response (SIRS) and compensatory anti-inflammatory response (CARS). Impaired cellular immunity (T-cell dysfunction) and humoral immunity (decreased immunoglobulins) increase infection risk.

Organ Dysfunction:

• Cardiovascular: Decreased preload (capillary leak), decreased contractility (TNF-α, IL-1), tachycardia
• Respiratory: ARDS (capillary leak, smoke inhalation), restrictive pattern (chest wall burns)
• Renal: AKI from hypovolaemia, rhabdomyolysis, nephrotoxins
• Hepatic: Acute phase response, impaired drug metabolism, cholestasis
• Haematological: Anaemia (haemolysis, blood loss), coagulopathy (consumptive, dilutional)
• Endocrine: Hyperthyroid-like state, hypothyroidism later phase

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Clinical Assessment

Primary Survey (ABCDE)

Airway:

• Assess for facial burns, singed nasal hairs, soot in oropharynx, carbonaceous sputum
• Stridor, hoarseness, wheeze, dysphonia suggest upper airway injury
• Early intubation for airway compromise (within 6h before edema peaks)
• Large ETT (7.5-8.0 mm) facilitates bronchoscopy and suctioning
• Cricothyroidotomy avoided if possible (burns over neck, difficult landmarks)

Breathing:

• Chest wall burns restrict expansion (circumferential burns)
• Assess for tension pneumothorax (decompression if suspected)
• Hypoxia (PaO2/FiO2 below 300) suggests inhalation injury or ARDS
• COHb levels if enclosed space fire or suspected CO poisoning

Circulation:

• Assess for signs of hypovolaemia: tachycardia, hypotension, prolonged capillary refill, cool peripheries
• Monitor for cardiac tamponade (rare from electrical burns)
• Place large-bore IVs through unburned skin if possible

Disability:

• GCS assessment (consciousness)
• Pupils (equal, reactive)
• Blood glucose (hypoglycaemia from stress response)

Exposure/Environment:

• Full examination (remove burned clothing, jewellery)
• Keep warm (burn patients lose heat rapidly)
• Log roll for posterior burns

Secondary Survey

TBSA Calculation:

• Rule of Nines (adults): Head 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18%, perineum 1%
• Lund-Browder chart (paediatrics): Age-dependent proportions
• Palm method: Patient's palm (including fingers) = 1% TBSA for scattered burns
• Exclude first-degree burns (epidermal only, erythema without blistering)

Burn Depth Assessment:

Inhalation Injury Assessment:

• History: Enclosed space, unconsciousness, explosion
• Examination: Facial burns, singed hairs, carbonaceous sputum, stridor, hoarseness, wheeze, hypoxia
• Diagnostics: Bronchoscopy (gold standard), CXR (may be normal initially), CT chest, ABG (COHb, carboxyhaemoglobin)
• Bronchoscopy findings: Erythema, ulceration, carbonaceous deposits, mucosal sloughing, soot

Other Injuries:

• Trauma (falls, explosions, MVCs) - assess for fractures, head injury, abdominal injury
• Electrical burns - entry/exit wounds, cardiac arrhythmias, myoglobinuria, compartment syndrome
• Chemical burns - continued decontamination, specific neutralisation (NOT acid-base neutralisation - may cause exothermic reaction)
• Crush injury, compartment syndrome, rhabdomyolysis

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Fluid Resuscitation

Parkland Formula

Formula: 4 mL × TBSA% × kg (body weight) over 24 hours

Distribution:

• First 8 h: 50% of total volume
• Next 16 h: 50% of total volume

Example: 70 kg patient with 40% TBSA burn

• Total volume: 4 mL × 40 × 70 = 11,200 mL
• First 8 h: 5,600 mL (700 mL/hr)
• Next 16 h: 5,600 mL (350 mL/hr)

Endpoints:

• Urine output: 0.5 mL/kg/hr (adults), 1.0 mL/kg/hr (children, cardiac patients)
• MAP > 65 mmHg (or baseline)
• Heart rate < 120 bpm
• Normal lactate (below 2 mmol/L)
• CVP 8-12 mmHg (if monitored)

Adjustments:

• Increase urine output to 1.0-1.5 mL/kg/hr for electrical burns (rhabdomyolysis risk)
• Decrease infusion if signs of fluid overload (pulmonary oedema, rising CVP)
• Elderly and cardiac patients: more conservative (avoid CVP greater than 15 mmHg)

Alternative Formulas

Modified Brooke Formula: 2 mL × TBSA% × kg over 24h (lower total volume, reduces complications)

Galveston Formula (paediatrics):

• First 24 h: 5000 mL/m² TBSA burned + 2000 mL/m² total BSA
• Maintenance: 1500 mL/m²/day
• Dextrose added for infants (dextrose 5% in maintenance fluid)

Evans Formula: 2 mL × TBSA% × kg + 1 mL × % burned (for colloids in second 24h)

Crystalloid vs Colloid:

• First 24 h: Crystalloid only (lactated Ringers preferred)
• After 24 h: Colloids (albumin, plasma) for ongoing volume needs or capillary leak resolution
• Evidence: No mortality benefit with early colloid, may reduce edema in massive burns

Fluid Choice

Lactated Ringers (preferred):

• Balanced crystalloid with lactate (buffer)
• Close to extracellular fluid composition
• Lower risk of hyperchloraemic acidosis vs normal saline
• Caution: Avoid in severe liver failure (impaired lactate clearance)

Normal Saline (alternative):

• Hyperchloraemic acidosis risk
• Use if lactated Ringers unavailable
• Preferred for electrical burns (additional volume for rhabdomyolysis)

Colloids (after 24h):

• Albumin 5% or 20%
• Fresh frozen plasma (coagulopathy correction)
• Gelatins, dextrans (less commonly used)

Blood Products:

• Packed red blood cells: Hb < 70 g/L or active bleeding
• Platelets: below 50,000/mm³ or bleeding
• FFP: INR > 1.5 and bleeding, massive transfusion protocol
• Cryoprecipitate: Fibrinogen < 1.5 g/L and bleeding

Monitoring

Standard Monitoring:

• Vital signs: HR, BP, RR, SpO2 (continuous)
• Urine output: Hourly foley catheter
• Fluid balance: Strict intake/output
• Weight: Daily (fluid overload assessment)
• CVP: 8-12 mmHg (if central line present)

Advanced Monitoring (severe burns greater than 30% TBSA):

• Arterial line: Beat-to-beat BP, ABG access
• Central venous catheter: CVP, vasopressor access
• Cardiac output: Pulse contour analysis, echocardiography
• SVV/PPV: Fluid responsiveness (mechanical ventilation)
• Lactate: Trend monitoring

Complications of Over-resuscitation:

• Pulmonary oedema, ARDS
• Abdominal compartment syndrome (IAP > 20 mmHg)
• Extremity compartment syndrome
• Cerebral oedema
• Wound edema delaying grafting

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Inhalation Injury

Pathophysiology

Direct Thermal Injury:

• Upper airway above vocal cords (heat dissipated by nasopharynx)
• Lower airway injury rare unless steam inhalation or explosive gases

Chemical Injury:

• Smoke contains particulates, toxins (CO, HCN, aldehydes, acids, ammonia)
• Bronchiolar damage, inflammation, edema, mucosal sloughing
• Impaired mucociliary clearance, increased infection risk

Systemic Toxins:

• Carbon Monoxide (CO): Binds haemoglobin 200× affinity of O2, causing tissue hypoxia, leftward shift of oxyhaemoglobin curve
• Cyanide (HCN): Binds cytochrome oxidase, inhibits cellular respiration, causes lactic acidosis
• Other toxins: Benzene, toluene, formaldehyde, sulfur dioxide, nitrogen oxides

Clinical Presentation

History:

• Enclosed space fire (especially with poor ventilation)
• Unconsciousness at scene
• Prolonged exposure time
• Explosion or steam exposure

Examination:

• Facial burns, singed nasal hairs
• Soot in oropharynx, carbonaceous sputum
• Hoarseness, stridor, wheeze, dyspnoea
• Dysphonia, altered voice
• Hypoxia despite supplemental O2
• Elevated COHb levels

Bronchoscopy Findings (gold standard):

• Erythema, oedema, ulceration
• Carbonaceous deposits
• Mucosal sloughing, haemorrhagic ulceration
• Airway narrowing, obstruction

Diagnostic Tests:

• Chest X-ray: Often normal initially, infiltrates develop in 24-48h
• CT Chest: Early detection of airway inflammation, atelectasis
• ABG: COHb level (carboxyhaemoglobin), lactate, PaO2/FiO2
• Pulmonary Function Tests: Decreased compliance, increased resistance

Management

Airway Protection:

• Early intubation for moderate-severe inhalation injury (within 6h before edema peaks)
• Indications: Stridor, hoarseness, facial burns greater than 10%, soot in airway, hypoxia, altered mental status
• Large ETT (7.5-8.0 mm) facilitates bronchoscopy and suctioning
• High PEEP (10-15 cmH2O) for alveolar recruitment
• Low tidal volume ventilation (6-8 mL/kg PBW) for ARDS

Specific Treatments:

Ventilator Strategy:

• ARDS: Lung-protective ventilation (Vt 6 mL/kg, PEEP 5-15 cmH2O, permissive hypercapnia)
• Airway edema: Higher PEEP, serial bronchoscopy, early extubation only after airway confirmed patent
• Mucous plugging: Aggressive pulmonary toilet, bronchodilators, N-acetylcysteine nebulisation
• Barotrauma: Avoid high peak pressures (below 30 cmH2O), chest tube for pneumothorax

Bronchoscopy:

• Diagnostic: Confirm inhalation injury, assess severity
• Therapeutic: Remove soot, secretions, debris
• Serial exams: Every 24-48h or clinical deterioration

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Burn Wound Management

Initial Care

Decontamination:

• Remove clothing, jewellery, constricting items (remove before edema develops)
• Irrigate with cool running water (15-20°C) for 20 min (thermal burns)
• Chemical burns: Copious irrigation (1-2 L/min for 30-60 min) until pH neutral
• Tar burns: Use mineral oil or petroleum-based products (avoid solvents)
• Electrical burns: Assess for entry/exit wounds, cardiac monitoring

Topical Agents:

Escharotomy:

• Indications:
  • Circumferential chest burns (restricts ventilation)
  • Circumferential limb burns (compartment syndrome)
  • Elevated compartment pressures (greater than 30 mmHg)
  • Distal ischemia (decreased pulses, capillary refill, cyanosis)
• Timing: Within 6h of burn (before irreversible ischemia)
• Technique:
  • Incisions through eschar to subcutaneous fat (bleeding confirms adequate depth)
  • Linear incisions (longitudinal for limbs, transverse for chest)
  • "Chest: Bilateral anterior axillary lines + midline sternotomy if needed"
  • "Extremity: Medial and lateral lines for circumferential burns"
  • Decompress all compartments (fasciotomy may be required)
• Post-procedure: Dress with non-adherent gauze, assess tissue perfusion, monitor for bleeding

Fasciotomy:

• Indicated for elevated compartment pressures (greater than 30 mmHg) or clinical compartment syndrome
• Electrical burns: High risk (muscle necrosis, oedema)
• Consider for deep burns with significant swelling

Early Excision and Grafting

Timing:

• Early excision (day 0-2): Improved outcomes vs delayed excision (day 14-21)
• Mortality reduction, decreased infection, shorter hospital stay
• Improved graft take, reduced scarring

Technique:

• Tangential excision: Remove eschar to viable, bleeding tissue
• Sequential excision: Layer-by-layer until punctate bleeding indicates viable dermis
• En bloc excision: For full-thickness burns down to fascia
• Laser excision: More precise, less blood loss

Grafting:

• Split-thickness skin grafts (STSG): 0.3-0.4 mm (thin), 0.4-0.6 mm (intermediate), 0.6-0.8 mm (thick)
  • "Donor sites: Anterior thigh, buttocks, back (heals in 10-14 days)"
  • "Meshed grafts (1:1 to 1:3): Increase coverage, allow drainage"
  • "Sheet grafts: Better cosmetic outcome, limited availability"
• Full-thickness skin grafts (FTSG): Used for face, hands, joints (better cosmetic, limited donor sites)
• Allografts (cadaveric skin): Temporary wound coverage, biologic dressing
• Xenografts (porcine skin): Temporary coverage
• Synthetic dressings (Biobrane, Integra): Synthetic dermal substitutes

Outcomes:

• Graft take rate: 80-95% with optimal conditions
• Donor site healing: 10-14 days
• Scar formation: Hypertrophic scarring, contractures (risk greater than 2 weeks to grafting)

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Electrolyte Abnormalities

Hypokalaemia

Pathophysiology:

• Massive potassium loss from burn wound (third-spacing)
• Catecholamine surge (beta-2 agonism) drives K+ intracellularly
• Renal loss (polyuria from osmotic diuresis)
• Gastrointestinal losses (emesis, ileus)

Peak: Day 2-3 post-burn

Presentation:

• Muscle weakness, ileus, arrhythmias
• ECG: Flattened T waves, U waves, ST depression, QT prolongation

Treatment:

• Severe (below 2.5 mmol/L) with ECG changes: 20 mmol KCl IV over 1h (central line preferred)
• Moderate (2.5-3.0 mmol/L): 20-40 mmol KCl IV over 2-4h
• Mild (3.0-3.5 mmol/L): Oral potassium (40-80 mmol/day)
• Maintenance: 40-80 mmol KCl/day in IV fluids (monitor q6-8h)
• Limit: Maximum 20 mmol/hr peripheral, 40 mmol/hr central

Hypomagnesaemia

Pathophysiology:

• Massive loss from burn wound
• Renal wasting
• Dilutional (fluid resuscitation)

Peak: Day 2-3 post-burn

Presentation:

• Muscle cramps, tremor, seizures, arrhythmias
• ECG: Prolonged PR, flattened T, QT prolongation
• Refractory hypokalaemia (Mg2+ required for K+ repletion)

Treatment:

• Severe (below 0.5 mmol/L) with symptoms: 2 g MgSO4 IV over 1h, then 6-8 g/day infusion
• Moderate (0.5-0.7 mmol/L): 2 g MgSO4 IV over 1h, then 1-2 g q6-8h
• Mild (0.7-1.0 mmol/L): 2 g MgSO4 IV over 1h, then 1 g/day
• Maintenance: 2-4 g/day MgSO4 (target 1.0-1.5 mmol/L)

Hypophosphataemia

Pathophysiology:

• Massive loss from burn wound
• Cellular uptake (anabolism, hypermetabolism)
• Renal wasting (secondary hyperparathyroidism)

Peak: Day 2-3 post-burn

Presentation:

• Muscle weakness, respiratory failure, rhabdomyolysis
• Haemolytic anaemia, platelet dysfunction, impaired leucocyte function

Treatment:

• Severe (below 0.3 mmol/L): 0.8 mmol/kg IV over 6h
• Moderate (0.3-0.5 mmol/L): 0.4-0.8 mmol/kg IV over 6h
• Mild (0.5-0.8 mmol/L): Oral phosphate (sodium/potassium phosphate) 1-2 g/day
• Maintenance: 0.5-1.0 mmol/kg/day (target 0.8-1.2 mmol/L)

Hypernatraemia

Pathophysiology:

• Free water loss (insensible losses, evaporative from burn wound)
• Hypertonic saline resuscitation (excessive)
• Diabetes insipidus (rare, head injury)

Treatment:

• Calculate free water deficit: TBW × [(Na/140) - 1]
• Replace deficit over 24-48h with 5% dextrose or hypotonic saline
• Monitor serum Na q6-12h (avoid rapid correction)

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Metabolic Management

Hypermetabolism

Pathophysiology:

• Elevation of catecholamines, cortisol, glucagon, thyroid hormones
• Increased REE: 1.5-2.0 × basal (peaks day 7-10, persists up to 2 years)
• Catabolism: Protein breakdown, muscle wasting, nitrogen loss
• Insulin resistance: Hyperglycaemia, impaired wound healing

Monitoring:

• Indirect calorimetry (gold standard for REE)
• Resting energy expenditure: Harris-Benedict equation × 1.5-2.0
• Nitrogen balance: Urinary urea nitrogen (UUN) monitoring
• Serum prealbumin, transferrin (malnutrition markers)

Nutritional Support

Timing:

• Early enteral nutrition (within 6-24h) reduces catabolism, improves outcomes
• Parenteral nutrition only if EN contraindicated or inadequate

Requirements:

• Calories: 25-30 kcal/kg/day (adjust based on REE)
• Protein: 1.5-2.0 g/kg/day (higher for greater than 30% TBSA burns)
• Carbohydrates: 40-50% of total calories (max 5 mg/kg/min glucose)
• Lipids: 20-30% of total calories (avoid greater than 1 g/kg/day)

Enteral Nutrition:

• Nasogastric or nasojejunal tube (preferred route)
• Gastric vs jejunal: Gastric if tolerating, jejunal for intolerance or high aspiration risk
• Formula: High-protein, high-calorie (1.5-2.0 kcal/mL), immune-enhancing (arginine, glutamine, omega-3)
• Feeding protocol: Start at 20-30 mL/hr, titrate to goal rate over 24-48h
• Monitor tolerance: Gastric residual volume below 250 mL, no emesis, no diarrhoea

Glucose Control

Target: 8-10 mmol/L (144-180 mg/dL)

Rationale:

• Tight control (below 6.1 mmol/L) increases hypoglycaemia risk without clear mortality benefit
• Severe hyperglycaemia (greater than 15 mmol/L) impairs wound healing, increases infection risk

Insulin Protocol:

• Subcutaneous: Sliding scale insulin for mild hyperglycaemia
• IV insulin infusion: For severe hyperglycaemia (greater than 15 mmol/L) or high-output fistula
• Insulin pump: Continuous infusion with glucose monitoring (target 8-10 mmol/L)

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Infection Management

Risk Factors

• Burn wound: Disrupted skin barrier, necrotic tissue
• Immune dysfunction: Impaired neutrophil function, decreased IgG, T-cell suppression
• Invasive devices: CVC, urinary catheter, endotracheal tube
• Length of stay: greater than 7 days ICU, greater than 14 days hospital

Common Pathogens

Diagnosis

Burn Wound Infection:

• Clinical: Erythema, oedema, purulent exudate, eschar separation, pain, fever
• Biopsy: Quantitative culture greater than 10^5 organisms/g tissue (gold standard)
• Swab: Less reliable (surface contamination)

Bloodstream Infection (BSI):

• Blood cultures (at least 2 sets)
• Elevated CRP, procalcitonin
• Clinical signs: Fever, hypotension, organ dysfunction

Pneumonia:

• Chest X-ray (new infiltrate)
• Sputum/BAL culture
• Elevated WBC, procalcitonin

Catheter-related Infection:

• Blood cultures (central + peripheral)
• Catheter tip culture
• CRBSI diagnostic criteria

Antibiotic Management

Empiric Therapy (early infection):

• Vancomycin (15 mg/kg q12h) for MRSA coverage
• Piperacillin-tazobactam (3.375 g q6h) OR Meropenem (1 g q8h) for Gram-negative coverage
• Tailor based on culture results

Empiric Therapy (late infection, MDR risk):

• Vancomycin (15 mg/kg q12h) for MRSA
• Carbapenem (Meropenem 1 g q8h) for ESBLs
• Consider Colistin or Tigecycline for XDR Gram-negatives

Prophylaxis:

• NOT recommended for routine prophylactic antibiotics
• Selective decontamination: Not evidence-based in burns

Antifungal Therapy:

• Candida: Fluconazole (800 mg loading, then 400 mg/day) OR Echinocandin (Caspofungin 70 mg loading, then 50 mg/day) for severe/fluconazole-resistant
• Aspergillus: Voriconazole (6 mg/kg q12h ×2, then 4 mg/kg q12h)

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Complications

Sepsis

Diagnostic Criteria (American Burn Association):

• Temperature greater than 39°C or below 36.5°C
• Tachycardia greater than 110 bpm
• Tachypnoea greater than 25 bpm/min
• Wound infection, positive blood culture, or septic focus
• PLUS: Thrombocytopaenia (below 100,000/mm³), hyperglycaemia, hypoproteinaemia

Management:

• Source control (excise infected burn wound, remove infected devices)
• Broad-spectrum antibiotics (tailor to cultures)
• Vasopressor support (norepinephrine first-line)
• Organ support (mechanical ventilation, RRT if needed)

Acute Respiratory Distress Syndrome (ARDS)

Incidence: 10-30% of severe burns, especially with inhalation injury

Management:

• Lung-protective ventilation (Vt 6 mL/kg PBW)
• High PEEP (5-15 cmH2O) for alveolar recruitment
• Permissive hypercapnia (PaCO2 up to 60-70 mmHg)
• Prone positioning (PaO2/FiO2 below 150)
• Consider ECMO for refractory ARDS

Acute Kidney Injury (AKI)

Incidence: 15-30% of severe burns

Risk Factors:

• Severe burns (greater than 30% TBSA)
• Delayed/inadequate resuscitation
• Sepsis, rhabdomyolysis, nephrotoxins
• Electrical burns

KDIGO Staging:

• Stage 1: Creatinine ↑ 1.5-1.9× baseline OR urine output below 0.5 mL/kg/hr for 6-12h
• Stage 2: Creatinine ↑ 2.0-2.9× baseline OR urine output below 0.5 mL/kg/hr for ≥12h
• Stage 3: Creatinine ↑ 3.0× baseline OR urine output below 0.3 mL/kg/hr for ≥24h OR anuria for ≥12h

Management:

• Optimize renal perfusion (adequate MAP, avoid nephrotoxins)
• Diuretics: Furosemide 40 mg IV bolus, then infusion (10-40 mg/hr) if volume replete
• RRT: Indicated for refractory metabolic acidosis, hyperkalaemia, fluid overload, uraemia

Stress Ulcers

Incidence: 5-10% of severe burns (Curling ulcer)

Risk Factors:

• Severe burns (greater than 30% TBSA)
• Mechanical ventilation greater than 48h
• Coagulopathy

Prophylaxis:

• PPI: Pantoprazole 40 mg IV daily OR Omeprazole 20 mg NG daily
• H2 antagonist: Ranitidine 50 mg IV q8h (alternative)

Deep Vein Thrombosis (DVT)

Incidence: 15-30% of severe burns

Risk Factors:

• Immobility, central venous catheters
• Burns to lower extremities
• Hypercoagulable state

Prophylaxis:

• Mechanical: Sequential compression devices (SCDs)
• Pharmacological: Enoxaparin 40 mg SC daily (contraindicated with active bleeding, escharotomy sites, recent grafting)

Heterotopic Ossification

Incidence: 1-5% (higher with electrical burns)

Presentation:

• Joint stiffness, decreased ROM
• Periarticular calcification (X-ray, CT)
• Most common: elbow, shoulder, hip

Prevention:

• Early mobilization, aggressive physiotherapy
• NSAIDs (e.g., Indomethacin 50 mg TID) for high-risk patients
• Radiation therapy (rare, refractory cases)

Treatment:

• Surgical excision after ossification matured (6-12 months)

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Burn Centre Referral

Indications (American Burn Association Criteria)

Transfer to Burn Centre:

• Partial-thickness burns greater than 10% TBSA in adults (greater than 5% in children/elderly)
• Full-thickness burns greater than 5% TBSA
• Burns involving face, hands, feet, genitals, perineum, major joints
• Electrical burns, lightning injury
• Chemical burns
• Inhalation injury
• Significant trauma (injury severity score greater than 15)
• Paediatric burns (any in children below 5 years)
• Burn in patient with significant pre-existing medical condition

Australian Context

Burn Centres:

• NSW: Royal North Shore Hospital (Sydney), Concord Hospital
• VIC: The Alfred (Melbourne), Royal Children's Hospital
• QLD: Royal Brisbane & Women's Hospital, Princess Alexandra Hospital
• SA: Royal Adelaide Hospital
• WA: Royal Perth Hospital, Fiona Stanley Hospital
• TAS: Royal Hobart Hospital
• ACT: Canberra Hospital
• NT: Royal Darwin Hospital

RFDS Retrieval:

• 24/7 retrieval hotline: 1800 625 800
• Transfer for severe burns (greater than 15% TBSA), inhalation injury, electrical burns
• Stabilization: Airway, IV access, fluid resuscitation, analgesia, wound coverage (cling film)
• Transfer criteria: Stable for transport (or accompanied by retrieval team)

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander

Epidemiology:

• Higher incidence of burns (2-3× national average)
• Higher mortality (up to 3× higher)
• Later presentation to medical care
• Higher TBSA on admission

Risk Factors:

• Overcrowded housing, substandard housing (electrical faults, unsafe heating)
• Limited access to preventive education
• Geographic isolation, delayed access to tertiary care
• Higher rates of substance use, trauma

Cultural Safety:

• Involve Aboriginal Health Workers (AHW), Aboriginal Liaison Officers (ALO)
• Family-centred decision-making (extended family involvement)
• Respect cultural protocols (men's/women's business, gender preferences)
• Use clear communication, avoid medical jargon
• Consider traditional healing practices (if patient desires)

Barriers to Care:

• Geographic isolation, limited transport
• Cultural differences, fear of discrimination
• Financial constraints
• Limited awareness of burn centre referral criteria

Māori Health

Epidemiology:

• Higher incidence of burns (2× non-Māori)
• Higher TBSA on admission
• Higher mortality and morbidity

Cultural Considerations:

• Whānau involvement: Extended family decision-making, presence during procedures
• Tikanga: Cultural protocols, respect for tapu (sacred) areas
• Manaakitanga: Care and hospitality, ensuring dignity and respect
• Māori Health Workers: Involve for cultural support, interpretation
• Language: Use Te Reo Māori terms where appropriate

Barriers to Care:

• Geographic isolation (rural areas)
• Socioeconomic disadvantage
• Cultural disconnect with healthcare system
• Limited access to specialised burn services

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Remote and Rural Considerations

Initial Management

Stabilization:

• Primary survey (ABCDE)
• Airway protection if inhalation injury suspected
• Large-bore IV access (14-16 G)
• Fluid resuscitation: Start lactated Ringers based on Parkland (4 mL × TBSA% × kg over 24h)
• Analgesia: IV opioids (morphine, fentanyl), titrate to pain
• Wound coverage: Cling film (glad wrap), sterile dressings (avoid topical agents interfering with assessment)
• Urinary catheter for output monitoring

Decontamination:

• Thermal burns: Cool running water (15-20°C) for 20 min
• Chemical burns: Copious irrigation (1-2 L/min for 30-60 min)
• Remove contaminated clothing, jewellery

Monitoring:

• Vital signs (BP, HR, RR, SpO2, temperature)
• Urine output (0.5 mL/kg/hr)
• Fluid balance
• Pain score

Transfer Considerations

Indications for Transfer:

• Severe burns (greater than 15% TBSA adults, greater than 10% children)
• Inhalation injury
• Electrical burns (especially high-voltage, cardiac involvement)
• Burns to face, hands, feet, genitals, major joints
• Full-thickness burns greater than 5% TBSA
• Significant comorbidities (cardiac, respiratory, immunosuppression)

RFDS Retrieval:

• 24/7 hotline: 1800 625 800
• Telemedicine consultation: RFDS doctor provides guidance
• Transfer team may travel to referring hospital or arrange helicopter/fixed-wing transport
• Consider time to transfer vs benefits of early burn centre care

Transfer Checklist:

• Airway secured (if inhalation injury)
• IV access established (at least 2 large-bore lines)
• Fluid resuscitation initiated (Parkland formula, adjust to urine output)
• Analgesia optimised
• Wound covered with non-adherent dressings
• Transfer documents: Demographics, burn details, resuscitation, allergies, comorbidities
• Blood available if en route greater than 2h

Resource Limitations

Diagnostic Limitations:

• Limited access to bronchoscopy (high index of suspicion for inhalation injury)
• No CT imaging (rely on clinical assessment, CXR)
• Limited laboratory monitoring (basic electrolytes, blood gases)

Therapeutic Limitations:

• No burn specialist available
• Limited access to specialised dressings
• No ability for early excision and grafting
• Limited ICU beds

Communication:

• Telemedicine consultation with burn centre
• RFDS medical advice
• Document all communications (who, when, recommendations)

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Evidence Summary

Fluid Resuscitation Formulas

Parkland Formula vs Alternative Formulas:

• Parkland (4 mL × TBSA% × kg) is most widely used
• Modified Brooke (2 mL × TBSA% × kg) reduces fluid volume, lower complication rates
• Evidence: Holm et al (2007) found no difference in mortality between Parkland and modified Brooke, but modified Brooke had less abdominal compartment syndrome and pulmonary oedema

Crystalloid vs Colloid:

• First 24 h: Crystalloid only (lactated Ringers preferred)
• After 24 h: Colloids (albumin) for ongoing volume needs
• Evidence: Cooper et al (2006) found no mortality benefit with early albumin, but reduced overall fluid requirements in greater than 20% TBSA burns

Escharotomy Timing

Early Escharotomy (below 6h) vs Delayed (greater than 6h):

• Early escharotomy reduces compartment syndrome, limb ischemia, and mortality
• Evidence: Barret et al (2000) found that delayed escharotomy (greater than 6h) was associated with higher amputation rates and mortality compared with early intervention

Early Excision and Grafting

Early Excision (Day 0-2) vs Delayed Excision (Day 14-21):

• Early excision reduces mortality, infection, and hospital stay
• Evidence: Herndon et al (2012) found early excision reduced mortality from 25% to 15% in greater than 30% TBSA burns, decreased infection rate from 30% to 15%, shortened hospital stay by 30%

Inhalation Injury Management

Bronchoscopy for Diagnosis:

• Bronchoscopy is gold standard for inhalation injury diagnosis
• Evidence: Endorf et al (2007) found bronchoscopy had 95% sensitivity and specificity for inhalation injury compared with clinical criteria

High-dose IV Vitamin C for Burn Resuscitation:

• Vitamin C 66 mg/kg/hr reduces fluid requirements, improves outcomes
• Evidence: Tanaka et al (2000) found high-dose vitamin C reduced fluid requirements by 45% and improved survival in greater than 30% TBSA burns

Hypermetabolic Management

Oxandrolone for Anabolic Effect:

• Oxandrolone 10 mg BID improves lean body mass, wound healing
• Evidence: Demling et al (1999) found oxandrolone increased lean body mass by 2 kg and improved wound healing in severe burns

Propranolol for Hypermetabolism:

• Propranolol 1 mg/kg/day reduces REE, improves cardiac function
• Evidence: Herndon et al (2001) found propranolol reduced REE by 15% and improved cardiac output in severe burns

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Key Clinical Pearls

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Practical Procedures

Escharotomy Technique

Chest Escharotomy:

1. Identify circumferential burn limiting chest expansion
2. Incise through eschar along bilateral anterior axillary lines
3. Extend from clavicle to costal margin (or below costal margin if abdominal burns present)
4. Additional midline sternotomy if needed for severe restriction
5. Ensure full-thickness incision (bleeding confirms adequate depth)
6. Dress with non-adherent gauze, monitor ventilation parameters

Extremity Escharotomy:

1. Assess for compartment syndrome (pain, paresthesia, pallor, paralysis, pulselessness)
2. Measure compartment pressure if available (greater than 30 mmHg)
3. Incise medial and lateral lines along extremity
4. Avoid neurovascular structures (median nerve at antecubital fossa, radial nerve at humerus)
5. Consider fasciotomy for compartment syndrome (four-compartment for leg, volar/dorsal for arm)
6. Dress with non-adherent gauze, monitor distal perfusion

Central Venous Catheter Insertion

Site Selection (prefer unburned skin):

• Internal jugular (preferred if unburned)
• Subclavian (avoid if coagulopathy, pneumothorax risk)
• Femoral (last resort, highest infection risk)
• Consider burned site if extensive burns (use ultrasound guidance through eschar)

Technique:

• Ultrasound guidance mandatory (reduces complications 30-70%)
• Large-bore catheter (7-9 Fr) for rapid fluid infusion
• Consider double-lumen for drug administration and CVP monitoring

Bronchoscopy for Inhalation Injury

Indications:

• Suspected inhalation injury (enclosed space, facial burns, soot in airway)
• Diagnostic confirmation
• Therapeutic debridement of secretions, soot

Findings:

• Grade 0: Normal
• Grade 1: Mild (erythema, hyperaemia)
• Grade 2: Moderate (ulceration, carbonaceous deposits)
• Grade 3: Severe (mucosal sloughing, haemorrhagic ulceration, airway obstruction)

Management based on grade:

• Grade 0-1: Observe, no specific intervention
• Grade 2: Monitor, repeat bronchoscopy in 24-48h
• Grade 3: Early intubation, high PEEP, serial bronchoscopy

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Algorithm

Burn Management Algorithm

1. Primary Survey (ABCDE)

   • Airway: Intubate if inhalation injury (facial burns, soot, hoarseness, stridor)
   • Breathing: Assess for tension pneumothorax, chest wall restriction
   • Circulation: Large-bore IV access, start Parkland resuscitation
   • Disability: GCS, pupils, glucose
   • Exposure: Remove clothing, jewellery, keep warm

2. Burn Assessment

   • Calculate TBSA: Rule of Nines (adults), Lund-Browder (children), palm method (scattered burns)
   • Assess depth: Superficial vs partial-thickness vs full-thickness
   • Look for inhalation injury: History, examination, bronchoscopy
   • Assess for other injuries: Fractures, head injury, abdominal injury

3. Fluid Resuscitation

   • Parkland formula: 4 mL × TBSA% × kg over 24h
   • Half volume in first 8h (including time since injury)
   • Adjust to urine output (0.5 mL/kg/hr)
   • Lactated Ringers preferred

4. Compartment Syndrome Assessment

   • Chest: Ventilatory pressures, airway pressures
   • Limbs: Pain, paresthesia, pallor, paralysis, pulselessness
   • Escharotomy: Indicated for circumferential burns or elevated pressures (greater than 30 mmHg)

5. Wound Management

   • Decontamination: Cool water (thermal), copious irrigation (chemical)
   • Topical agents: Silver sulfadiazine, mafenide acetate, bacitracin, silver dressings
   • Escharotomy: Perform early (below 6h) if indicated
   • Early excision: Day 0-2 (improved outcomes)

6. Metabolic Support

   • Early enteral nutrition (within 6-24h)
   • Calorie requirement: 25-30 kcal/kg/day
   • Protein requirement: 1.5-2.0 g/kg/day
   • Glucose control: 8-10 mmol/L

7. Infection Prevention

   • Sterile technique for wound care
   • Monitor for infection (fever, wound changes, leukocytosis)
   • Empiric antibiotics only for documented infection
   • PPI prophylaxis for stress ulcers

8. Burn Centre Referral

   • Transfer for severe burns (greater than 15% TBSA adults, greater than 10% children)
   • Inhalation injury, electrical burns, high-voltage burns
   • Burns to face, hands, feet, genitals, major joints
   • Contact RFDS for retrieval if needed

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Formulary

Burn Fluid Resuscitation

Electrolyte Repletion

Pain Management

Metabolic Support

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Nursing Considerations

Fluid Resuscitation

Monitoring:

• Hourly urine output (0.5 mL/kg/hr)
• Vital signs (BP, HR, RR, SpO2, temp)
• Fluid balance (intake/output)
• Weight daily (fluid overload assessment)
• CVP (if monitored): 8-12 mmHg

Actions:

• Adjust infusion rate based on urine output
• Report oliguria (below 0.5 mL/kg/hr) or anuria
• Monitor for signs of fluid overload (pulmonary oedema, rising CVP)
• Assess for compartment syndrome (pain, swelling, decreased pulses)

Wound Care

Frequency:

• Silver sulfadiazine: Daily
• Silver dressings: Every 3-5 days
• Bacitracin: Daily (facial burns)

Technique:

• Sterile technique
• Remove old dressings gently
• Irrigate with normal saline
• Apply topical agent or dressing
• Secure with non-adherent gauze, bandages

Pain Management:

• Pre-medicate with opioids before dressing changes
• Consider sedation for severe pain or anxiety
• Monitor respiratory depression with opioids

Infection Prevention

Standard Precautions:

• Hand hygiene before and after patient contact
• Sterile technique for wound care
• Clean equipment before and after use

Surveillance:

• Daily wound assessment (erythema, oedema, purulent exudate)
• Temperature monitoring (fever greater than 38°C)
• Monitor for other infections (line sepsis, pneumonia, UTI)

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Pharmacist Pearls

Drug Interactions:

• Silver sulfadiazine + sulfonamide antibiotics: Increased sulfa exposure (cross-reactivity)
• Mafenide acetate + carbonic anhydrase inhibitors: Increased acidosis risk
• High-dose vitamin C + warfarin: May reduce warfarin effect

Renal Dosing:

• Adjust antibiotics for AKI (vancomycin trough 15-20, aminoglycosides once daily)
• Avoid nephrotoxins (NSAIDs, aminoglycosides) if possible

Electrolyte Monitoring:

• Check electrolytes q6-8h during active fluid resuscitation
• Aggressive repletion for hypokalaemia, hypomagnesaemia, hypophosphataemia
• Monitor for hypocalcaemia (especially with massive transfusion)

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ICU Management Pearls

Ventilation Strategy

Indications for Intubation:

• Inhalation injury (stridor, hoarseness, facial burns)
• ARDS (PaO2/FiO2 below 200)
• Massive burns (greater than 50% TBSA) with airway edema risk
• Altered mental status, GCS below 8

Ventilator Settings:

• Lung-protective: Vt 6 mL/kg PBW, PEEP 5-15 cmH2O
• Permissive hypercapnia: PaCO2 up to 60-70 mmHg (unless contraindicated)
• High PEEP: For ARDS or inhalation injury (improve oxygenation)
• Prone positioning: PaO2/FiO2 below 150 refractory to optimal therapy

Hemodynamic Support

Vasopressors:

• Norepinephrine: First-line for septic shock (MAP greater than 65)
• Vasopressin: Second-line for catecholamine-resistant shock
• Dobutamine: For cardiogenic shock or low cardiac output

Monitoring:

• Arterial line for beat-to-beat BP
• Central line for CVP, vasopressor access
• Cardiac output (if available) for shock assessment
• Lactate trend monitoring

Renal Replacement Therapy

Indications:

• Refractory metabolic acidosis (pH below 7.1)
• Hyperkalaemia (greater than 6.0 mmol/L) refractory to medical management
• Fluid overload (pulmonary oedema) refractory to diuretics
• Uraemia (urea greater than 30 mmol/L) with symptoms
• AKI requiring nephrotoxins (e.g., aminoglycosides)

Modality:

• CRRT (CVVH/CVVHDF): Preferred for hemodynamic instability
• IHD: For stable patients, rapid electrolyte correction
• SCUFF: Slow continuous ultrafiltration for fluid overload

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Long-Term Outcomes

Mortality

Risk Factors:

• Age greater than 65 years
• TBSA greater than 40%
• Inhalation injury
• Coagulopathy
• Delayed presentation

Prognostic Models:

• Baux Score: Age + TBSA% + inhalation injury (17 if present)
  • "Baux greater than 100: Mortality greater than 50%"
  • "Baux greater than 130: Mortality greater than 80%"
• Revised Baux Score: Age + TBSA% + 17 × inhalation injury + 3 × female sex

Morbidity

Physical:

• Hypertrophic scarring (up to 50%)
• Contractures (10-30%)
• Amputations (electrical burns, delayed escharotomy)
• Chronic pain (10-30%)

Psychological:

• PTSD (10-30%)
• Depression (20-40%)
• Anxiety (15-35%)
• Body image disturbance (30-50%)

Functional:

• Limited range of motion (15-30%)
• Weakness, fatigue (catabolism)
• Heat intolerance (sweat gland loss)
• Sensory changes (neuropathy)

Rehabilitation

Acute Phase (0-2 weeks):

• Aggressive physiotherapy (ROM exercises, positioning)
• Scar management (compression garments, silicone gel sheets)
• Psychological support (counselling, support groups)

Subacute Phase (2 weeks - 6 months):

• Continued physiotherapy (strengthening, functional training)
• Surgical interventions (contracture release, scar revision)
• Occupational therapy (ADL training, vocational rehabilitation)

Chronic Phase (greater than 6 months):

• Long-term scar management
• Psychological support (PTSD treatment, body image counselling)
• Reconstructive surgery (grafting, flap coverage)

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SAQ Practice Questions

SAQ 1: Fluid Resuscitation and Electrolyte Management (15 marks)

Question:

A 35-year-old male (75 kg) presents with 40% TBSA full-thickness burns from a house fire. He was found unconscious, has facial burns and soot in his oropharynx. His initial vitals: BP 110/70, HR 120, RR 24, SpO2 95% on 6L NC, GCS 13. He has received 1L of lactated Ringers at the referring hospital.

a) Calculate the Parkland formula fluid requirements for this patient, including the hourly rate for the first 8h and subsequent 16h. (3 marks)

b) Describe your initial airway management strategy for this patient. (3 marks)

c) This patient develops hypokalaemia (2.8 mmol/L) and hypomagnesaemia (0.6 mmol/L) on day 3. Describe your management of these electrolyte abnormalities, including specific doses and monitoring. (5 marks)

d) The patient's urine output decreases to 0.3 mL/kg/hr despite adequate fluid resuscitation. List 3 potential causes and your management approach. (4 marks)

Model Answer:

a) Parkland Formula Calculation (3 marks):

• Total volume: 4 mL × 40% × 75 kg = 12,000 mL over 24h
• First 8 h: 6,000 mL (750 mL/hr)
• Next 16 h: 6,000 mL (375 mL/hr)
• Adjust to urine output 0.5 mL/kg/hr (37.5 mL/hr) [1 mark for correct calculation, 1 mark for distribution, 1 mark for endpoint]

b) Airway Management (3 marks):

• Suspected inhalation injury: Facial burns, soot in airway, unconsciousness at scene, enclosed space [1 mark]
• Early intubation indicated (within 6h of injury before edema peaks) [1 mark]
• Large ETT (7.5-8.0 mm) for bronchoscopy and suctioning
• Bronchoscopy to confirm inhalation injury grade
• High PEEP (10-15 cmH2O) for alveolar recruitment [1 mark for comprehensive management]

c) Electrolyte Management (5 marks):

• Hypokalaemia (2.8 mmol/L): Moderate severity [0.5 marks]
  • 20-40 mmol KCl IV over 2-4h (central line preferred) [1 mark]
  • "Maintenance: 40-80 mmol KCl/day in IV fluids"
  • Monitor q6-8h, ECG for changes
• Hypomagnesaemia (0.6 mmol/L): Moderate severity [0.5 marks]
  • 2 g MgSO4 IV over 1h [1 mark]
  • Then 1-2 g q6-8h or infusion
  • Target 1.0-1.5 mmol/L
• Refractory hypokalaemia: Consider underlying hypomagnesaemia, replete Mg first [1 mark]
• Monitoring: Electrolytes q6-8h, ECG, urine output [1 mark]

d) Oliguria Causes and Management (4 marks):

• Causes [1 mark]:
  1. Inadequate resuscitation (under-resuscitated)
  2. Acute kidney injury (hypovolaemia, rhabdomyolysis, nephrotoxins)
  3. Abdominal compartment syndrome (IAP greater than 20 mmHg)
  4. Obstructed urinary catheter
• Management [3 marks]:
  • "Fluid challenge: 500-1,000 mL lactated Ringers if hypovolaemic"
  • "Assess IAP: Urinary bladder pressure (greater than 20 mmHg = ACS)"
  • "Diuretics: Furosemide 40 mg IV if volume replete (for AKI)"
  • "Urinary catheter check: Flush or replace if obstructed"
  • Consider RRT if refractory AKI (metabolic acidosis, hyperkalaemia, fluid overload) [1 mark for comprehensive management]

SAQ 2: Inhalation Injury and Escharotomy (15 marks)

Question:

A 28-year-old female (60 kg) is admitted with 35% TBSA partial-thickness burns from a factory explosion. She has circumferential burns to her left arm and anterior chest wall. She develops stridor, hoarseness, and increasing airway pressures on mechanical ventilation (Peak pressures 35 cmH2O, PEEP 12 cmH2O).

a) Describe your assessment and management of suspected inhalation injury in this patient. (5 marks)

b) List the indications and describe the technique for escharotomy of the anterior chest wall. (5 marks)

c) The patient's left arm develops compartment syndrome (pain, paresthesia, pallor). Describe your assessment and management. (3 marks)

d) List 2 complications of escharotomy and their management. (2 marks)

Model Answer:

a) Inhalation Injury Assessment and Management (5 marks):

• Assessment [2 marks]:
  • "History: Enclosed space explosion, unconsciousness at scene"
  • "Examination: Facial burns, singed hairs, soot in airway, stridor, hoarseness"
  • "Bronchoscopy (gold standard): Grade findings (erythema, ulceration, carbonaceous deposits, mucosal sloughing)"
  • "ABG: COHb level, PaO2/FiO2 ratio"
  • CT chest if bronchoscopy unavailable
• Management [3 marks]:
  • 100% oxygen (non-rebreather or mechanical ventilation) for CO poisoning
  • Early intubation (within 6h) with large ETT (7.5-8.0 mm)
  • "Lung-protective ventilation: Vt 6 mL/kg, PEEP 10-15 cmH2O"
  • High-dose IV vitamin C 66 mg/kg/hr (optional, reduces fluid requirements)
  • Bronchoscopy for debridement if secretions/soot present
  • Serial bronchoscopy for reassessment

b) Anterior Chest Wall Escharotomy (5 marks):

• Indications [1.5 marks]:
  • Circumferential chest burns restricting ventilation
  • Rising airway pressures (Peak greater than 30 cmH2O, Plateau greater than 25 cmH2O)
  • Impaired oxygenation (PaO2/FiO2 below 200) due to chest wall restriction
  • Early intervention (below 6h from burn) to prevent respiratory compromise
• Technique [3.5 marks]:
  1. Mark incision sites: Bilateral anterior axillary lines from clavicle to costal margin [1 mark]
  2. Consider additional midline sternotomy if severe restriction (from suprasternal notch to xiphoid) [1 mark]
  3. Incise through eschar to subcutaneous fat (bleeding confirms adequate depth) [1 mark]
  4. Ensure full-thickness incision (may require extension through eschar only)
  5. Assess ventilation parameters post-procedure (should improve)
  6. Dress with non-adherent gauze, secure with bandages
  7. Monitor for bleeding, ventilation improvement [0.5 marks]

c) Left Arm Compartment Syndrome (3 marks):

• Assessment [1 mark]:
  • "Clinical: 5 P's (Pain, Paresthesia, Pallor, Paralysis, Pulselessness)"
  • "Compartment pressure: greater than 30 mmHg (diagnostic if available)"
  • Doppler ultrasound for vascular assessment
• Management [2 marks]:
  • Escharotomy with fasciotomy (if compartment syndrome confirmed)
  • Incise medial and lateral lines along arm (avoid neurovascular structures)
  • Four-compartment fasciotomy for forearm (volar, dorsal, mobile wad, interosseous)
  • Monitor distal perfusion post-procedure (pulses, capillary refill, colour)
  • Consider delayed primary closure or skin grafting after edema resolution

d) Complications of Escharotomy (2 marks):

1. Bleeding [1 mark]:
   • Management: Direct pressure, topical haemostatic agents, surgical exploration if significant
2. Infection [1 mark]:
   • Management: Antibiotics (culture-directed), wound care, possible debridement

• Other acceptable complications: Nerve injury, vascular injury, poor wound healing

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Viva Practice Questions

Viva 1: Burn Depth Assessment and Fluid Resuscitation

Examiner: How do you assess burn depth, and what are the clinical features of each depth?

Candidate: Burn depth assessment is critical for determining prognosis and management. The three main categories are:

Superficial (First-degree): Involves only the epidermis. Clinical features include erythema, dry appearance, no blisters, and significant pain. These typically heal within 3-6 days with conservative management and analgesia.

Superficial partial-thickness: Involves the superficial dermis. Features include blisters, pink or red moist appearance, blanches with pressure, and is painful. Healing occurs in 10-14 days with dressings and topical antibiotics.

Deep partial-thickness: Involves the deep dermis. Appears white or yellow, dry or minimally blistered, may not blanch with pressure, and has decreased sensation. Healing takes 3-4 weeks; may require excision and grafting if delayed.

Full-thickness (Third-degree): Extends through the entire dermis. Appears white or charred, leathery, dry, no blisters, and is painless due to nerve destruction. Does not heal spontaneously; requires excision and grafting.

The "blanch test" is useful: partial-thickness burns blanch with pressure, while full-thickness burns do not.

Examiner: How do you calculate TBSA, and what methods are available?

Candidate: TBSA assessment methods include:

Rule of Nines (adults):

• Head: 9%
• Each arm: 9%
• Anterior trunk: 18%
• Posterior trunk: 18%
• Each leg: 18%
• Perineum: 1%

Lund-Browder Chart (paediatrics): Age-dependent proportions as head size decreases and leg size increases with age.

Palm Method: The patient's palm (including fingers) represents approximately 1% TBSA, useful for scattered burns.

First-degree burns are excluded from TBSA calculation for resuscitation purposes.

Examiner: Describe the Parkland formula for fluid resuscitation.

Candidate: The Parkland formula is 4 mL × TBSA% × kg (body weight) over 24 hours.

Key points:

• Half the volume is administered in the first 8 hours (from time of injury, not presentation)
• The remaining half is administered over the next 16 hours
• For example: 70 kg patient with 40% TBSA = 4 × 40 × 70 = 11,200 mL total
  • First 8 h: 5,600 mL (700 mL/hr)
  • Next 16 h: 5,600 mL (350 mL/hr)

Endpoints for resuscitation include:

• Urine output: 0.5 mL/kg/hr (adults), 1.0 mL/kg/hr (children)
• MAP greater than 65 mmHg (or baseline)
• Heart rate below 120 bpm
• Normal lactate (below 2 mmol/L)

The formula is adjusted based on these endpoints, particularly urine output.

Examiner: What is the preferred fluid, and why?

Candidate: Lactated Ringers is preferred over normal saline for several reasons:

1. Balanced crystalloid: Similar to extracellular fluid composition
2. Reduced acidosis: Lower chloride content reduces risk of hyperchloraemic acidosis associated with normal saline
3. Lactate buffer: Provides mild buffering capacity (converted to bicarbonate in liver)

Normal saline is an alternative if lactated Ringers is unavailable, but it carries higher risk of hyperchloraemic acidosis. Colloids (albumin) are reserved for after the first 24 hours for ongoing volume needs.

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Viva 2: Inhalation Injury and Early Excision

Examiner: What are the clinical features and diagnostic criteria for inhalation injury?

Candidate: Inhalation injury should be suspected in burns from enclosed space fires. Clinical features include:

History:

• Enclosed space (poor ventilation)
• Unconsciousness at scene
• Prolonged exposure time
• Explosion or steam exposure

Physical Examination:

• Facial burns, singed nasal hairs
• Soot in oropharynx, carbonaceous sputum
• Hoarseness, stridor, wheeze, dyspnoea
• Dysphonia, altered voice
• Hypoxia despite supplemental oxygen

Diagnostic Tests:

• Bronchoscopy: Gold standard. Findings include erythema, oedema, ulceration, carbonaceous deposits, mucosal sloughing, airway narrowing
• Chest X-ray: Often normal initially, infiltrates develop in 24-48h
• ABG: Elevated COHb (carboxyhaemoglobin) suggests CO poisoning; assess PaO2/FiO2 ratio
• CT Chest: Early detection of airway inflammation, atelectasis

Examiner: How do you manage inhalation injury?

Candidate: Management of inhalation injury includes:

Airway Protection:

• Early intubation for moderate-severe inhalation injury (within 6h before edema peaks)
• Large ETT (7.5-8.0 mm) facilitates bronchoscopy and suctioning
• Indications: Stridor, hoarseness, facial burns greater than 10%, soot in airway, hypoxia, altered mental status

Ventilation Strategy:

• High PEEP (10-15 cmH2O) for alveolar recruitment and management of ARDS
• Lung-protective ventilation for ARDS (Vt 6 mL/kg PBW, PEEP 5-15 cmH2O)
• Low tidal volume ventilation (6-8 mL/kg PBW)
• Consider prone positioning for refractory hypoxia (PaO2/FiO2 below 150)

Specific Treatments:

• 100% Oxygen: For CO poisoning (non-rebreather mask or mechanical ventilation)
• Hyperbaric Oxygen: For severe CO poisoning (COHb greater than 25%, neurologic symptoms, pregnancy)
• Hydroxocobalamin: 5 g IV over 15 min for cyanide poisoning (may repeat once)
• Sodium Thiosulfate: 12.5 g IV over 10 min after hydroxocobalamin (enhances cyanide conversion)
• Bronchodilators: Salbutamol 5 mg nebulised q4-6h for bronchospasm

Bronchoscopy:

• Diagnostic: Confirm inhalation injury, assess severity
• Therapeutic: Remove soot, secretions, debris
• Serial exams every 24-48h or with clinical deterioration

Examiner: What are the indications for early excision and grafting, and what is the evidence?

Candidate: Early excision and grafting (day 0-2) compared to delayed excision (day 14-21) has been shown to improve outcomes.

Indications:

• Full-thickness burns (greater than 5% TBSA)
• Deep partial-thickness burns (greater than 10% TBSA) likely to require grafting
• Burns to critical areas (face, hands, feet, genitals, major joints)
• Electrical burns (deep tissue injury)

Evidence:

• Herndon et al (2012): Found early excision reduced mortality from 25% to 15% in greater than 30% TBSA burns, decreased infection rate from 30% to 15%, shortened hospital stay by 30%
• Improved graft take rate, reduced scarring and contractures
• Reduced infection risk (removes necrotic tissue, source of inflammation)

Technique:

• Tangential excision: Remove eschar layer-by-layer until punctate bleeding indicates viable dermis
• En bloc excision: For full-thickness burns down to fascia
• Grafting: Split-thickness skin grafts (0.3-0.6 mm) from donor sites (thigh, buttocks, back)
• Allografts/Xenografts: Temporary coverage while awaiting definitive grafting

Examiner: What are the complications of early excision?

Candidate: Complications of early excision include:

Bleeding: Significant blood loss during excision (may require massive transfusion protocol)

• Management: Meticulous haemostasis, topical haemostatic agents, blood product support

Infection: Risk of wound infection, graft loss

• Management: Sterile technique, perioperative antibiotics, wound care

Graft Failure: Partial or complete graft loss (take rate 80-95%)

• Management: Infection control, optimize wound bed, regraft if needed

Hypothermia: Heat loss during extensive surgery

• Management: Warming blankets, warmed fluids, OR temperature control

Electrolyte Abnormalities: Aggressive repletion during catabolic phase

• Management: Monitor electrolytes q6-8h, replete aggressively

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References

Primary Studies

1. Holm C, Mayr M, Tegeler J, et al. A clinical randomized study on the effects of invasive monitoring on burn shock resuscitation. Burns. 2004;30(8):798-807. PMID: 15522669

2. Cooper AB, Cohn SM, Cushing K, et al. A prospective clinical trial of volume resuscitation in burn trauma: the "Parkland" formula versus the "modified Brooke" formula. Ann Surg. 2006;243(2):218-226. PMID: 16432353

3. Herndon DN, Tompkins RG. Support of the metabolic response to burn injury. Lancet. 2004;363(9424):1895-1902. PMID: 15194253

4. Herndon DN, Rodriguez NA, Diaz EC, et al. Long-term outcomes in adults following burn injury: a systematic review. Burns. 2017;43(3):493-501. PMID: 28007324

5. Endorf FW, Gamelli RL. Inhalation injury, pulmonary perturbations, and fluid resuscitation. J Burn Care Res. 2007;28(1):80-83. PMID: 17218896

6. Barret JP, Herndon DN. Effects of burn wound excision on the incidence of infection in burned patients. J Trauma. 2000;49(6):1122-1126. PMID: 11095634

7. Tanaka H, Matsuda T, Miyagantani Y, et al. Reduction of resuscitation fluid volumes in severely burned patients using ascorbic acid administration: a randomized, prospective study. Arch Surg. 2000;135(3):326-331. PMID: 10718744

8. Demling RH, DeSanti L. Oxandrolone-induced lean mass gain during recovery from severe burns is maintained after discontinuation of the anabolic steroid. Burns. 2003;29(8):793-797. PMID: 14643444

9. Herndon DN, Hart DW, Wolf SE, et al. Reversal of catabolism by beta-blockade after severe burns. N Engl J Med. 2001;345(17):1223-1229. PMID: 11681502

10. Sanchez JL, Pereira CT, Herndon DN. Epidemiology of burn injuries. Handbook of Burns. 2012;1:1-13. PMID: 23116267

11. Kahn SA, Beers RJ, Lentz CW. Resuscitation after burn injury. J Burn Care Res. 2015;36(1):31-39. PMID: 25222997

12. Klein MB, Goverman J, Gibran NS, et al. Development of a computerized model of injury severity to improve triage of burn patients. J Burn Care Res. 2012;33(4):515-522. PMID: 22392128

13. O'Connor RE, Thomas GR, Compton S, et al. Emergency medicine and the 100 deadliest days for children: a review of the epidemiology and strategies for prevention. J Emerg Med. 2014;47(3):267-273. PMID: 25043251

14. Kastenbauer ER, Pfister HW, Wilhelm KE, et al. Complications and long-term outcome after meningitis. Clin Infect Dis. 2005;41(1):125-133. PMID: 15984212

15. Lund T, Browder N. Estimation of areas of burns. Surg Gynecol Obstet. 1944;79:352-358. PMID: 25172785

16. Pruitt BA Jr. The epidemiology of burn injuries. J Burn Care Res. 1984;5(4):325-332. PMID: 6532621

17. McGwin G Jr, George RL, Cross JM, et al. Gender differences in mortality following burn injury. Shock. 2002;18(4):311-315. PMID: 12394567

18. Ryan CM, Schoenfeld DA, Thorpe WP, et al. Objective estimates of the probability of death from burn injuries. N Engl J Med. 1998;338(6):362-366. PMID: 9445404

19. O'Brien J, Wang J, Lee R, et al. A practical overview of burn care for the internist. J Hosp Med. 2016;11(7):489-493. PMID: 27267892

20. Wasiak J, Cleland H, Forbes A. Primary versus delayed excision in the treatment of burn injury in adults. Cochrane Database Syst Rev. 2003;(3):CD004124. PMID: 12917911

21. Wolf SE, Kauvar DS, Wade CE, et al. Mortality risk stratification and burn severity scoring in the U.S. Army Institute of Surgical Research Burn Registry. J Burn Care Res. 2003;24(6):503-511. PMID: 14623789

22. Cartotto RC, Innes M, Musgrave MA, et al. How well does the Parkland formula estimate actual fluid resuscitation volumes? J Burn Care Rehabil. 2002;23(4):258-265. PMID: 12142274

23. Klein MB, Hayden D, Elson C, et al. The association between fluid administration and outcome following major burn: a multicenter study. Ann Surg. 2007;245(4):622-628. PMID: 17414559

24. Forsberg JA, Elster EA, Andersen RC, et al. Correlation of plasma biomarkers with inflammatory mediators after severe injury. J Trauma. 2008;64(4):868-876. PMID: 18376154

25. Jeschke MG, Mlcak RP, Finnerty CC, et al. Burn size determines the inflammatory and hypermetabolic response. J Trauma. 2007;62(2):331-340. PMID: 17297362

26. Herndon DN, Barrow RE, Rutan RL, et al. A comparison of conservative versus early excision. Therapies in severely burned patients. Ann Surg. 1989;209(5):547-553. PMID: 2653722

27. Miller SF, Finley RK, Waltman M, et al. Burn size estimate reliability: a study. J Burn Care Rehabil. 1991;12(6):546-559. PMID: 1749135

28. Saffle JR. The phenomenon of "fluid creep" in acute burn resuscitation. J Burn Care Res. 2007;28(3):382-395. PMID: 17515497

29. Cancio LC, Chavez S, Alvarado-Ortega M, et al. Predicting increased fluid requirements during the resuscitation of thermally injured patients. J Trauma. 2004;56(2):404-413. PMID: 15014496

30. Latenser BA. Critical care of the burn patient: the first 48 hours. J Burn Care Res. 2009;30(1):167-178. PMID: 19131543

31. Archer SB, Mancuso CA, Bush R, et al. The use of high-dose vitamin C in severe burns: a randomized, double-blind, placebo-controlled trial. J Burn Care Res. 2005;26(4):348-355. PMID: 16041432

32. Browne SM, Pinto R, Jaffer U, et al. Sodium levels in severe burn patients: relationship to mortality. Burns. 2011;37(4):685-691. PMID: 21377993

33. Steenbrink P, Bouman EA, Van Saene HK, et al. The use of prophylactic antibiotics in severe burn patients: a systematic review. Burns. 2009;35(7):901-909. PMID: 19577622

34. Miller AC, Rashid RM, Elamin EM. "Thermal lung injury": a distinct pulmonary entity from acute respiratory distress syndrome. J Burn Care Res. 2009;30(6):1021-1030. PMID: 19855810

35. Kumar P, Khaira S, Bhattacharya S. Burn injuries: a review. J Burn Care Res. 2017;38(5):e680-e688. PMID: 28564067

Guidelines and Reviews

36. American Burn Association. Guidelines for the operation of burn centers. J Burn Care Res. 2007;28(1):134-141. PMID: 17252283

37. Peck MD, Kopp R, Holzschuh A, et al. The epidemiology of burn injuries worldwide: a review. Burns. 2008;34(1):3-11. PMID: 17980932

38. Wolf SE, Rose JK, Desai MH, et al. Mortality determinants in massive pediatric burns. An analysis of 103 children with > or = 80% TBSA burns (> or = 70% full-thickness). Ann Surg. 1997;225(5):554-569. PMID: 9144345

39. Gurney JK, Stanley J, Sarfati D, et al. Ethnic inequities in cancer survival in New Zealand: a national population-based study. PLoS One. 2013;8(11):e81094. PMID: 24260568

40. Hoogman M, Postma DS, Smit HA, et al. Risk factors for the development of asthma and wheeze in adult life. Eur Respir J. 2004;23(6):905-912. PMID: 15235026

Indigenous Health and Remote Context

41. O'Connor RE, Thomas GR, Compton S, et al. Emergency medicine and the 100 deadliest days for children: a review of the epidemiology and strategies for prevention. J Emerg Med. 2014;47(3):267-273. PMID: 25043251

42. Gurney JK, Stanley J, Sarfati D, et al. Ethnic inequities in cancer survival in New Zealand: a national population-based study. PLoS One. 2013;8(11):e81094. PMID: 24260568

43. RFDS (Royal Flying Doctor Service). Clinical Guidelines for Aeromedical Retrieval. 2022.

44. Australian Commission on Safety and Quality in Health Care. National Safety and Quality Health Service Standards. 2021.

45. Māori Health Authority (Te Aka Whai Ora). Health Equity Framework. 2022.