Circulation

• Burns >20% total body surface area (TBSA) can cause profound circulatory shock that can occur from both large fluid losses through tissue damage and from a systemic inflammatory response.⁶
• Haemodynamic instability is rarely due to the burn alone and should prompt us to look for other causes
• Circumferential limb burns can compromise blood supply distally.

Assessment

• A thorough assessment of the extent of a burn is paramount.
• Capillary refill time (CRT), blood pressure and mucous membrane assessment are important indicators of hydration status but may be hard to measure due to location of the burn.⁹
• Though rarely immediately helpful in the Emergency Department setting, early catheterisation is important as urine output is a reliable sign that can demonstrate poor perfusion and serve as a guide to ongoing resuscitation.^9,11
• In a significant burn there can be an increased metabolic demand on the patient which can cause organ dysfunction. Therefore, important baseline tests to consider are full blood count, urea and electrolytes, coagulation profile, liver function tests, amylase, C-reactive protein and capillary blood glucose. This also helps to identify any other issues impacting on the patient. If the patient is likely to go to theatre a serum group and save is warranted.
• In circumferential limb burns, blood supply to the extremities should be checked regularly. If unable to do this clinically, a Doppler ultrasound can be used.^9-11

Management

1. Immediate intravenous (IV) access and, if required, fluid resuscitation are critical steps in initial care.^9-11
2. Blood tests
3. Evaluate any areas of circumferential burns in limbs and constantly reassess perfusion.

Any deterioration in the circulation to a limb could indicate ischaemia or a compartment syndrome. This warrants immediate discussion with a burns centre and may require urgent intervention such as escharotomy or fasciotomy.⁹

Learning bites

• IV access is paramount. If it is not possible to get IV or IO access through unburnt skin, access is mandated through burnt tissue.
• Creatine kinase is a useful test to perform to assess muscle breakdown.