THRIVE in Children at Different Flow Rates

Study Overview
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Brief Summary
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This study investigates under controlled circumstances the concept of THRIVE to improve the ventilation and the carbon dioxide elimination, to prolong the apnoea time without deoxygenation and to improve safety of airway management in pediatric patients.

Detailed Description
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Eligible, consented children will be prepared for general anaesthesia in the usual way. After start of anesthesia (=induction), adequate face-mask ventilation will be established. The sealed envelope for randomisation will then be opened. Standard anesthesia will be continued, either using sevoflurane or propofol (anesthesia depth controlled by Narcotrend, to measure anesthesia depth using processed EEG waves). They will receive additional non-invasive monitoring for this study, such as transcutaneous measurement of tcCO2 and O2, NIRS, and thoracic electrical impedance tomography (EIT, PulmoVista® 500, Draeger, Luebeck, Germany) All patients will receive neuromuscular blockade medication of 2 x ED95 (standard intubation dose) to facilitate airway management and total intravenous anesthesia will be installed (continuous application of i.v. anesthesia medication). Up to two minutes of bag-mask ventilation with 100% oxygen and flow rates of 6-8L/min will be applied until an expired oxygen concentration of >90% is reached, as well as an SpO2 of 100% and an transcutaneous CO2 of 30-40mmHg. For the study intervention, the bag-mask ventilation will be discontinued, and the child will be left apnoeic (the same happens always during intubation) until the saturation drops to 95%, which is still a low normal value. According randomization, any of the two study intervention s will be applied (THRIVE therapy with 100% O2 2l/kg/min, THRIVE therapy with 100% O2 4l/kg/min, all via nasal cannulas) while simultaneously guaranteeing an open airway by using Esmarch's procedure (jaw thrust) and an oral airway (Guedel tube). ECG, pulse-oximetry, blood pressure, Narcotrend, NIRS, thoracic EIT, PtcO2, PtcCO2 will be measured continuously over the study period. The time until desaturation from SpO2 100% to SpO2 95% will be also measured. A chest ultrasound at the end of the intervention will prove that no pneumothorax developed during the procedure. The study intervention will end at the time the saturation reaches SpO2 95% or when any other break-up criteria are reached. Bag mask ventilation will then be re-applied until SpO2 reaches again 100% and the patient will be treated according to the attending anaesthesiologist to ultimately establish a patent airway. Break-up criteria during apnoea are: SpO2 below 95%, transcutaneous CO2 above 70 mmHg, or time of apnoea >10 minutes. Drop of NIRS > 30% from baseline. A postmedication interview will be performed before PACU discharge.

Official Title
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THRIVE (Transnasal Humidified Rapid Insufflation Ventilatory Exchange) in Children at Different Flow Rates

Conditions
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Apnea, Ventilation Therapy; Complications

Intervention / Treatment
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* Other: THRIVE 4L/kg/min
* Other: THRIVE 2L/kg/min


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: paediatric patients undergoing elective surgery requiring general anesthesia with intubation at the University Hospital - Inselspital in Bern. ASA physical status 1&2 10-15kg legal guardians providing written informed consent. Exclusion Criteria: known or suspected difficult intubation oxygen dependency congenital heart or lung disease obesity BMI>20kg/m2 high aspiration risk (requiring rapid sequence induction intubation).

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 4 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: THRIVE 2L/kg/min using OptiFlow<br>High-flow nasal cannula therapy with 2L/kg/min with 100% oxygen via OptiFlow by Fisher&Paykel, Auckland, New Zealand. | Other: THRIVE 2L/kg/min<br>* High-flow nasal cannula therapy with 2L/kg/min with 100% oxygen via OptiFlow by Fisher&Paykel, Auckland, New Zealand.<br>* Other names: Optifloe;|
| Experimental: THRIVE 4L/kg/min using OptiFlow<br>After apnea sets in and mask ventilation is successfully established, randomization envelopes are opened and according to group allocation, the following oxygen delivery system is applied. High-flow nasal cannula therapy with 4L/kg/min with 100% oxygen via OptiFlow by Fisher&Paykel, Auckland, New Zealand. | Other: THRIVE 4L/kg/min<br>* High-flow nasal cannula therapy with 4L/kg/min with 100% oxygen via OptiFlow by Fisher&Paykel, Auckland, New Zealand.<br>* Other names: Optiflow;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of tcCO2 in mmHg/min | mean tcCO2 increase in mmHg/min during apnoea time, measured transcutaneously. | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| desaturation from SpO2 100% to 95% | time (in seconds) until desaturation from SpO2 100% to 95% | 10 minutes | 
| tcO2 in mmHg/min | Changes in tcO2 in mmHg/min | 10 minutes | 
| NIRS | changes in brain oxygenation (measured by near infrared spectroscopy (NIRS)) during apnoea time | 10 minutes | 
| Electrical impedance tomography | changes in electrical impedance tomography (EIT) to validate ventilatory effect | 10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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infant, airway management, apneic oxygenation