Application of THRIVE in Burn Children With Suspected Difficult Airway

In order to improve intubation conditions in burn children, our aim is to investigate the efficacy of transnasal humidified rapid-insufflation ventilatory exchange technique（THRIVE) in children aged between 0 and 18 years who with head, face, and neck injuries by fire, scalding, chemical, electric,explosions, and others. We hypothesise that THRIVE increases first attempt success without hypoxemia in intubation of children and compared with routine practice.

Does the THRIVE can prolong apnoea time and delay the onset of desaturation to increase the success rate of the first tracheal intubation without desaturation?

Researchers will compare THRIVE group with Routine care group to see successful intubation on the first attempt without desaturation.

Participants will received intravenous anesthesia induction, followed by 2-3 minutes preoxygenation, before intubation, the mask was removed from the children's face and a THRIVE nasal plug was placed. During intubation, the Routine care group had no oxygen supply,and the THRIVE group will be maintained throughout the apnoeic period with selected flow rates during intubation attempts.

The incidence of burns is four times higher in children than in adults: burn injuries account for about 25% of all paediatric hospitalisations. Approximately 70 percent of children who attend hospital with burns or scalds are less than five years of age. The most common cause is hot liquids. Direct heat and steam injury to the upper airway can lead to marked swelling of the face, tongue, epiglottis, and glottic opening, resulting in airway obstruction,especially for these who burned with head,face and neck. Dressings and nasogastric tubes may make face mask seal difficult, facial wounds may be painful, and exudate and topical antibiotics may make for a slippery surface and difficult for anesthesiologist to holding the mask during preoxygenation phase. However,In children, awake intubation is not a viable option. Therefore, intubation is often attempted after Rapid Sequence Intubation (RSI) by set up a vein line after inhalation anesthesia in the operating room. But the lower functional residual capacity and greater metabolic demand of children made the onset of desaturation in apnoeic children occurs much faster than in adults at induction of anaesthesia and is known to be age dependent. If the desaturation occurs, oxygen mask is often required to manually assist ventilation, until SPO2 recovery after another attempt to intubation. Attempting more than two tracheal intubations in children with difficult endotracheal intubation is associated with a high failure rate and increased incidence of complications.

Preoxygenation does not supply an ongoing gas exchange and therefore there is an urgent need for newer methods to continue improved oxygenation during the apnoeic phase.Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has potential in pre-oxygenation for RSI anaesthesia since it provides high-flow humidified oxygen through nasal cannulae and allows continued peri-laryngoscopy oxygen delivery during apnoea.

Therefore, investigator propose the hypothesis that children with head, face, and neck burns or thermal scalds use THRIVE during endotracheal intubation after anesthesia induction, It can prolong the safe apnoea oxygenation time and increase the success rate of the first intubation without SPO2 decrease ≤90%.

No sedative was applied before patients entering the operating room. All patients were put in the"sniffing" position with a 2-2.5 cm pad placed under shoulder in order to maintain upper airway patency. Intravenous anesthesia was induced with fentanyl 2ug/kg-1 and propofol 2-3mg/kg-1 and vecuronium 0.1 mg/kg-1, respectively,(for children without or with difficulty in set up vein line, 8% sevoflurane was inhaled, and after I.V. access was established,Sevoflurane were discontinued,followed by Intravenous induction), (The preoxygenation phase is defined as the period in preparation for intubation where oxygen is delivered to The patient to maximize oxygen concentration in the functional residual capacity of The lung), and wait 2-3 min for vecuronium to takes effect after reaching end-expiratory oxygen saturation \> 90%,the manual ventilation is stopped and according to different groups, different intervention was performed. Routine care group: after stopping manual ventilation, the inestigators immediately removed the mask and placed the nasal plug in place but without oxygen supply, and the anesthesiologist began to intubation; THRIVE group: after stopping manual ventilation, the investigators immediately ceasing assisted ventilation, the age-appropriate nasal prongs were applied and weight-specific high flow rates delivered using The Optiflow THRIVETM system. The flow rates applied were as follows: 0-15kg, 2litres KG-1 Min-1; 15-30kg, 35litres Min-1; 30-50kg, 40litres Min-1; and \& GT; 50kg, 50litres Min-1,and start to tracheal intubation.

If SPO2 ≤ 90% appears during intubation, then perform manual ventilation immediately until SPO2 returned to 100% endotracheal intubation was performed again and recorded as second attempt intubation.

Monitoring of anesthetic depth was not possible because The surgical site involved The head and face.

Eligibility Criteria:
Inclusion Criteria:

* \< 18 years
* ASA Grade I \~ III
* Children with head, face and neck scald or burn or flame or electrical c hemical or other

Exclusion Criteria:

* Refusal or failure to sign an informed consent
* Proposed to transnasal intubation
* Fracture of the nasal bone, nasal bleeding, nasal deformity or obstruction
* Tracheotomy status or severe head, face and neck burn or burn scar (difficult airway)
* Unsuitable for rapid sequence induction
* Basicranial fracture
* Cyanotic congenital heart defect
* At risk of malignant hyperthermia
* And is participating in other clinical studies