03 EMSB BURNS 2013 (36) Flashcards
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BURN FIRST AID
- put the fire out
- remove any still hot clothing, remove any jewellery*
- COOL THE BURN under cool running water for 20m within the first 3h: do immediately if onscene, after the primary survey if seen subsequently.
- simultaneously WARM THE PATIENT with warm fluids, environs etc
- cover with GLADWRAP
- ELEVATE to reduce swelling
- no topical creams etc unless >24h from burns unit, and on their advice
* the whole patient is going to swell!
WHAT TO DO WITH STUCK CLOTHING IN BURNS PATIENTS
- pull it gently off, any skin that follows was non viable anyway
- if very stuck, cut around
EMSB INITIAL BURNS PATIENT MANAGEMENT ALGORITHM
- Patients with burn injuries are initially managed like any other trauma patient, using standard ATLS protocols (Primary survey etc)
- this helps prioritise emergency interventions, eg Intubation, and identify associated traumatic injuries
- certain parts of the process are then specific to the burn patient, eg estimation of burn depth, area and replacement fluids
SKIN ANATOMY AND CLASSIFICATION OF BURN DEPTH
- The skin consists of 2 layers, the thin, superficial EPIDERMIS, which constantly sheds, and the thicker, deeper DERMIS, containing the hair follicles, sweat glands, nerves, vessels etc.
- The Dermis rests upon a layer of subcutaneous fat and fascia, allowing the skin to move over the deeper layers.
- Burn depth is no longer categorised anatomically as First/Second/Third degree etc, but rather prognostically according to its ablity to heal: viz
- SUPERFICIAL BURNS: burns where ample epidermal and Dermal cells survive to allow rapid healing by insitu regeneration of the skin, (eg Epidermal burns & Superficial Dermal burns)
- MID THICKNESS BURNS: burns where sufficient Epidermal (in hair follicles) and Dermal cells survive for spontaneous healing by regeneration, although not rapidly (ie Mid Dermal burns)
- DEEP BURNS: burns where few (Deep Dermal) or no (Full Thickness) skin cells survive: these burns heal only slowly and with much scarring
NAME THE 3 ZONES OF A BURN WOUND
Tissue damage in a burn wound can be divided into 3 zones:
- A central ZONE OF COAGULATION, where the cells are cooked and dead
- A (relatively thin) surrounding ZONE OF STASIS, where the cells survive, but are compromised by a damaged micro-circulation. Ongoing cell death in this zone may result in burns extending in area and depth over time.
- A surrounding ZONE OF HYPERAEMIA, where the tissues are not physically burned, but are hyperaemic due to inflammatory mediators released from the burn. With a large burn (> 20% TBSA), virtually all the unburned skin (and indeed all organ systems) become part of the zone of hyperaemia
ESTIMATING BURN DEPTH BY EYE
Burns which are
- Just INTACT ERYTHEMA = EPIDERMAL burns, eg sunburn
- WET & BLISTERED = DERMAL burns (Blisters have a non viable roof separated from a viable base by oedema fluid: with increasing depth of burn the colour of the base deepens from pink to red as it gets closer to the deep dermal vessels, becoming non blanching when full thickness)
- DRY, WHITE & INSENSATE* = FULL THICKNESS, with both Epidermis and Dermis destroyed *
although most full thickness burns will have have partial thickness patches or perimeters which are painful
ESTIMATING BURN AREA in ADULTS & CHILDREN
- For ADULTS, the standard WALLACE RULE OF NINES is used, with the palmar area of the hand (including fingers) equating to 1% when summating multiple small burns
-
For CHILDREN, with their larger heads and smaller legs, the Rule of Nines is modified thus:
- At 1yr, the Head = 18% (not 9%), and each leg = 13.5% (not 18%)
- each year, 1% is taken from the head and half added to each leg until adult proportions are attained at age 10.
CALCULATING FIRST 24H FLUID REQUIREMENTS FOR ADULT BURNS PATIENTS
- Inflammatory mediators released from burned tissues cause massive oedema formation in the first 24h, both in the burn, and generally.
- For large burns (> 20% TBSA), formal burns fluid replacement is required, using the MODIFIED PARKLAND FORMULA:
- HARTMANS, 3mls/kg/%* burn over 24h, half in the first 8h. (or 10-20L in the first 24h for a big burn)
- titrate to a U/O of 0.5 ml/kg/h (not more, over-resuscitation exaccerbates oedema)
* counting dermal burns or deeper! NOT intact epidermal burns
CALCULATING FIRST 24H FLUID REQUIREMENTS FOR BURNED CHILDREN
- Children have larger surface area to volume ratios, and thinner skin, so they burn more easily.
- They also concentrate urine poorly, and have limited glucose stores, so we
- begin formal burn fluid replacement with the MODIFIED PARKLAND FORMULA earlier, at 10% TBSA (not 20%)
- add glucose containing maintenance fluids viz: 5%D in NS, at the 4:2:1 rate
- titrate to a U/O of 1 ml/kg/h, not 0.5
BURNS FLUIDS IN THE 2ND 24H
- Oedema formation settles in the 2nd 24H, so fluid replacement changes in volume and composition to:
- 5% ALBUMIN*, 0.5mls/kg/%burn/day (1-2L in a big burn)
- 4%DNS/5, titrated to U/O of 0.5 ml/kg/h
- add ORAL fluids as tolerated, and start NE feeding ASAP
* not given on D1 as it just leaks into the tissues, exaccerbating oedema
IV ACCESS OPTIONS IN BURNS PATIENTS
- Peripheral lines, central lines and IOs placed through intact or burned skin are all options.
- peripheral IVs (and Art lines) placed in burned skin should be sutured
- in many big burns, the groin creases will be spared, facilitating groin line placement
NGTs in BURNS PATIENTS
the combination of
- their propensity for ileus
- the benefits of early NE feeding (better nutrition, less sepsis from GI bacterial translocation)
means NGT are indicated for all large burns, ie > 20% TBSA in adults > 10% TBSA in children
IDCs IN BURNS PATIENTS
- As hourly urine output is the key indicator of adequate fluid resuscitation in burns patients, IDCs are indicated for all large burns, ie
- > 20% TBSA in adults
- > 10% TBSA in children
PERINEAL BURNS
- should be catheterised early, before they swell
HAEMOGLOBINURIA AND MYOGLOBINURIA
Release of Haemoglobin and Myoglobin from injured tissues, may result in their renal excretion, with
- brownish-red urine
- renal tubular blockage and ARF
TREATMENT
- address cause if able, eg COMPARTMENT SYNDROME
- double U/O to 1-2 ml/kg/h with IVT +/- MANNITOL
- urinary alkalinisation with BICARB is no longer recommended, based upon the evidence
WHAT’S THE DIFFERENCE BETWEEN ESCHAROTOMY AND FASCIOTOMY?
- ESCHAROTOMY = incision of a rigid burn eschar down to subcutaneous fat to relieve pressure which is causing limb ischaemia or resp compromise. Its a relatively superficial procedure, and is generally painless, only requiring LA for the viable ends of the incisions
- FASCIOTOMY = incision dividing the fascia over a tight muscle compartment. It is a deeper incision, normally requiring GA
ESCHAROTOMY : HOW?
- can be done bedside in emergency but best taken to theatre for full surgical prep etc
- mark lines of incision, generally along the A-P junctions of the limbs*, and an H centered on the costal margins, and with with verticals along the AAL, for the trunk, continuing few mm onto normal skin
- anaesthesia is not reqd, just LA for the viable ends
- incise down to fat with scalpel or diathermy, look for visible separation
- expect a lot of bleeding: control with local measures (diathermy, ties, stats), NOT pressure bandages
* just do one side of the finger
2 NERVES NOT TO CUT WHEN DOING ESCHAROTOMY
Do not cut:
- the ULNAR NERVE at the elbow
- the LATERAL POPLITEAL NERVE over the fibular head
skirt around!
THE 4 ‘P’s of COMPARTMENT SYNDROME
the 4 Ps are:
- PAIN*
- PARAESTHESIA
- PARALYSIS
- PULSE LOSS & POOR PERIPHERAL PERFUSION
* PERSISTENT PAIN in an at risk limb is the principle red flag, pulse loss is a late sign, and even ‘normal’ compartment pressures (<10mmHg) do NOT reliably rule out CS
A LIMB WITH COMPARTMENT SYNDROME IS….
ROCK HARD
TUBES NEEDED FOR SERIOUS BURNS
- IVT, probably CVC & Art
- NGT
- IDC
- +/- ETT
ICE WATER IRRIGATION FOR BURNS
Whilst COOL WATER irrigation is an excellent first aid treatment that reduces pain and burn extension, ICED WATER should not be used as it
- exaccerbates hypothermia
- may cause vasoconstriction or cold injury which extends the burn
INHALATION INJURY IN BURNS PATIENTS
- Inhalation injury should be suspected in burns patients with a history of entrapment, and with evidence of facial burns, especially involving steam (which carries more heat).
- Inhalation of hot gases may cause
- airway burns
- pulmonary burns
- systemic toxicity due to CO, Cyanide etc
- all are indications for early Intubation and ventilation with 100% O2
CARBON MONOXIDE POISONING
- CO is a colourless, odourless gas produced by the incomplete combustion of carbon.
- It binds very strongly to Hb, with a dissociation half life of 250 minutes in room air, reducing the oxygen carrying capacity of the blood.
- Detection of this deficit is, however, difficult because:
- CO-Hb gives the skin a deceptively pink colour
- Regular Pulse Oximeters cannot detect it, special CO-OXIMETERS are required, but levels of up to 15% are normal in smokers, and asymptomatic
- Arterial gas analysis measures the pO2, not saturation, which may remain normal in CO poisoning
- a significant part of the toxicity of CO occurs inside the cell, due to disruption of INTRACELLULAR CYTOCHROMES, irrespective of O2 delivery
TREATMENT
- assume all confused burns patients have CO poisoning
- give O2 at 15 LPM to enhance washout
- consider ETT and 100% O2, esp if resp burns suspected
- HYPERBARIC O2 is usually logistically too difficult and benefit debatable