Airway Burns and Inhalation Injury Management Paediatric Intensive Care Unit (044)

• CXR: especially if air transfer (usually normal at baseline)
• Blood gas: co-oximetry (carboxyhaemoglobin), lactate, PaCO2, PaO2

Resuscitation:

• Prevent ongoing burn injury
• Increase calculated fluid requirements if inhalation and burn injury present

No factors accurately and consistently predict the need for intubation. It is a clinical decision, ie not based on laboratory data. Drooling, stridor, hoarseness, facial or neck burn or increased work of breathing mandate intubation.

• Consultant anaesthetic staff/ PICU staff must be informed of all upper airway burns
• Intubate early-oedema progresses and is worsened by fluid resuscitation
• Signs may be minimal at presentation but rapidly progress. If the child is not intubated they must be observed in an area where continuous cardiorespiratory assessment with appropriate monitors is available. Staff must be appropriately trained to recognise a child with evolving airway compromise, and facilities for intubation must be available.
• Err on the side of caution - IF IN DOUBT INTUBATE
• The child should be intubated if they need transferring between hospitals
• Senior staff experienced in intubation of the difficult airway should intubate
• Do not cut the endotracheal tube (evolving oedema can result in a cut tube being too short. The theoretical risk of increasing dead space is minor in comparison.)
• Nasal intubation is preferable (but a difficult oral intubation should not be electively changed for a nasal tube)
• The largest cuffed tube that is age appropriate should be used. Ideally this is a “microcuff tube”. The cuff should remain deflated (inflate if respiratory compliance and resistance compromises ventilation).
• If “microcuff ” tubes are unavailable then the largest age appropriate plain tube should be placed up to size 5.5, and cuffed tubes size 6.0 and above.
• Fix the tube so that it can be advanced in the first few days if necessary-once oedema has settled, suturing or stapling can be considered
• Elevate the head of the bed to 30-45o( this allows gravity drainage of oedema, and the abdominal viscera to move away from the diaphragm)

Children with lower airway injury that have required intubation should be managed in a PICU. It is possible that a child has deteriorated as lower airway injury has progressed, requiring intubation after a period of observation. These children should be referred to a PICU.

Injury may not manifest until after 48 hours. Toxins produce bronchospasm, mucosal oedema, microvascular hyperpermeability, obstructive airway casts and surfactant dysfunction.

Depressed epithelial integrity, loss of the mucocilairy clearance mechanism, migration of upper airway secretions to the lower airway and immuno-compromise predispose to bacterial colonization and translocation. Lower airway injury may progress to the acute respiratory distress syndrome. Strategies should be targeted to minimize iatrogenic ventilator induced lung injury. Intubation is as per upper airway thermal injury. (Suxamethonium can be used to facilitate intubation in the absence of a cutaneous burn injury. If there is a burn injury present then Suxamethonium can be used in the first 24 hours. Its use is contraindicated after 24 hours from a cutaneous burn).

The requirement for invasive lines can be discussed with the retrieval team. The retrieval team can site lines as indicated if the referring hospital are unable to gain access.

• Arterial line
• Central venous (ideally continuous SVO2monitoring)
• End tidal CO2monitoring

• 100% humidified oxygen until CO levels <10%
• No place for routine use of hyperbaric oxygen therapy

Cyanide toxicity is uncommon. Cyanide levels are not routinely performed by hospital biochemistry services, and have to be sent to reference laboratories. For this reason they cannot be used to influence management. The routine use of antidotes is not recommended as they have significant side effects. Priority should be given to stabilising the airway. The use of Cyanide antidotes should be discussed with a PICU consultant. Therapy will be influenced by local availability of antidotes.

Suspect Cyanide poisoning if

• Lactate remains elevated despite adequate resuscitation
• High mixed venous oxygen saturation
• Low arterial venous oxygen difference

It is expected that the child will already be on a PICU. Bronchoscopy should not be performed by the referring hospital unless it is to assist an emergency intubation, or because the child cannot be ventilated after being intubated.

• Only appropriately trained personnel should perform bronchoscopy.
• Consider after intubation to support diagnosis and obtain baseline microbiology specimens this needs balanced against the risk of hypoxia or loss of the airway.
• As required for bronchial toilet and removal of airway secretions and casts.
• To obtain microbiology specimens if chest infection is not improving on therapy targeted at blind bronchial alveolarlavage cultures.
• Prior to extubation if concerns from earlier bronchoscopy.
• MLB if child fails extubation.

• Days 2 and 3 to obtain microbiology specimens. (See separate Guideline)
• Thereafter on clinical suspicion of lower airway infection
• To confirm treatment success at end of antibiotic course
• Daily if adopting the Shriners Bronchial Toilet Schedule (see below)

• Emergency airway
• Elective – currently no evidence of benefit. Consider in individual cases of protracted intubation.

These patients are at risk of ARDS and iatrogenic ventilator induced lung injury. The standard of care for mechanical ventilation in inhalation injury has not been established. Local protocols for ventilating a patient with Acute Lung Injury should be adhered to these will be dependant on ventilator modes available. Lung protective strategies should be adopted. Any child requiring ventilation should be discussed with PICU pending transfer.

• 4 hourly physiotherapy is the mainstay of bronchial toilet. Salbutamol nebulisers should be used to treat bronchospasm.
• Bronchoscopy may be needed to assist with bronchial toilet. (send specimens for microscopy, culture and sensitivity whenever bronchoscopy is performed).
• Antibiotics for proven infection-Narrow spectrum and targeted where possible. Limit to 1-week intravenous. Confirm clearance with BAL specimens

There is animal model evidence for the use of nebulised heparin and nebulised N-acetylcysteine. Whilst it is standard practice insome paediatric burn’s centres, its routine use cannot be recommended. The Shriner’s Bronchial Toilet Schedule is presented below.

• Local protocols for weaning and extubation should be followed.
• Ensure airway swelling has resolved prior to extubation.
• Ensure staff who are trained in managing the difficult airway are available at the time of extubation as post extubation stridor can still occur.

• Naso-gastric tube and commence feeds at outset. If not tolerated early passage of Naso -jejunal tube
• Dietetic support to optimise nutrition

• Should be considered in any patient failing conventional ventilation
• Debridement and grafting should ideally be done before commencing ECMO This can be a complex decision involving the whole Team and the family.

• Steroids: No indication for routine use. Limit to bronchospasm, and peri-extubation. Consider use in ARDS.
• Eschars of the chest and upper abdomen can restrict ventilation and do not require to be circumferential in children to compromise ventilation significantly. Escharotomy can improve ventilation.
• Consider placing a peritoneal drain if ascites is compromising ventilation

The following is the Shriners policy, which can be adopted at the discretion of the PICU consultant.

• 4 Hourly chest physiotherapy (half an hour after Nacetylcysteine)
• 2 hourly side to side turning
• 6 hourly proning
• Cough, deep breathing exercises 2 hourly where practicable
• Nebulise 3ml 20% N-acetylcysteine with Salbutamol (2.5mg < 5 years of age, 5mg>5 years of age) 4 hourly
• Nebulise 5000 units Heparin with 3ml normal saline every 4 hours (alternate with N-acetylcysteine ie nebulisers every 2 hours)
• Endotracheal suctioning as needed
• Daily bronchial alveolar lavage
• Monitor coagulation profile daily whilst on nebulised Heparin