Clinical trial NCT03478774: Physiology Regarding Apnoeic Oxygenation During Nasal Cannula Therapy at Different Flow Rates
Official title: Physiology Regarding Apnoeic Oxygenation During Nasal Cannula Therapy at Different Flow Rates
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Apnoeic Oxygenation
Lead sponsor: Insel Gruppe AG, University Hospital Bern
Sponsor class: OTHER
First posted: 2018-03-27
Enrollment: 125
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: SINGLE_GROUP
Intervention model description: single centre, prospective, randomized-controlled trial
Primary purpose: TREATMENT

Brief summary: This study compares under controlled conditions if different flow rates affect apnoea time after induction of anaesthesia and how CO2 clearance is influenced. Furthermore, this study enables to quantify the effects of increased pCO2 on vital parameters (e.g. blood pressure, cardiac output, cerebral perfusion, etc.) The investigators will enroll patients undergoing elective surgery at the University Hospital of Bern, Switzerland.

Once anesthesia has been induced, apnoea will set it. During this period, the investigators will compare different methods of apnoeic oxygenation for a maximum of 15 or 30 minutes.

Before discharge, an interview will be conducted, assessing complications and patient satisfaction.

Detailed description: Eligible, consenting adults will be prepared for general anaesthesia in the usual way consisting of ECG, pulse-oximetry, NarcotrendTM, a venous cannula and an arterial line for continuous blood pressure monitoring. They will receive additional monitoring such as transcutaneous measurement of pCO2 and O2, NIRS, and thoracic electrical impedance tomography (EIT, PulmoVista® 500, Draeger, Luebeck, Germany).

Normal pre-oxygenation (until etO2 is \> 90% or time \> 3 minutes) will occur. Anaesthesia will be started (= "induction") using Propofol and Fentanyl, using NarcotrendTM to measure depth of anaesthesia. All patients will receive a standard dose of neuromuscular blockage to facilitate airway management and total intravenous anaesthesia will be installed. Using the train of four measurement (TOF) full neuromuscular blockage with Rocuronium will be confirmed every 30 seconds. If necessary, additional dosage of neuromuscular blockage will be administered.

After administration of Rocuronium, possibility of mask ventilation will be confirmed and the sealed envelope with the randomization will then be opened. As a study intervention, the assigned method (HFNCT 70 l/min with either jaw thrust or laryngoscopy, or 10 l/min or 2l/min with the standard nasal canula, or 0.25l/min delivery of oxgen via a tracheal tube) will be installed and mask ventilation discontinued starting the apnoea period. Nasopharyngoscopy (EF-N slim, Acutronic, Hirzel, Switzerland) will confirm upper airway patency. Blood gas analysis will be conducted: baseline awake, start of apnoea, first minute after apnoea start, and every 2 minutes thereafter with a maximum of 75ml 150 ml in total. Other measurements (ECG, pulse-oximetry, blood pressure, NIRS, thoracic EIT, NarcotrendTM, PtcO2, PtcCO2) will be measured continuously over the study period The study intervention will end when one of the following criteria (study end-points) is met: SpO2 \<92%, PtcCO2 \> 100 mmHg or time \> 30 minutes.

When any of the end points is reached, patient-centred standard anaesthesia care will be continued, as planned for the case.

A post-operative interview will be conducted before discharge to evaluate injuries during airway management (bleeding, sore throat, hoarseness), pain, postoperative nausea and vomiting.

Eligibility criteria: Inclusion Criteria:

* \> 18 years
* Written informed consent
* Undergoing elective surgery
* Requiring general anesthesia

Exclusion Criteria:

* Any Indication for fibre optic intubation
* Expected impossible mask ventilation
* Known coronary heart disease
* Known heart failure, NYHA classification ≥ 2
* Therapy including β-receptor antagonists
* Arrhythmias in need of anti-arrhythmic therapy (e.g. implanted cardio defibrillator)
* Peripheral occlusive arterial disease, Fontaine ≥ 2b
* Known stenosis of the (common or internal) carotid or vertebral arteries
* BMI \> 35kg/m2 and BMI \< 16kg/m2
* Hyperkalaemia (K \> 5.5 mmol/l)
* Known COPD Gold classification ≥ 2
* Known pulmonary arterial hypertension, systolic \> 35mmHg
* Known obstructive sleep apnoea syndrome in need of therapy
* High risk of aspiration (requiring rapid sequence induction intubation)
* Increased intracranial pressure
* Intracranial surgery
* Limited knowledge of German language
* Absent power of judgement
* Anaemia, Hb \< 100 g/l
* Pregnancy (pregnancy test in all female patients)
* Neuromuscular disorder
* Known or suspected cervical spine instability
* Nasal obstruction, impossibility of nasal ventilation (both sides patent)
* Allergies or contra-indications to one or more of the used anaesthesia agents

Primary outcomes:
measure: pCO2 increase in kPa/min
timeFrame: 15 or 30 minutes (maximum apnea time)
Secondary outcomes:
measure: Lowest Saturation
timeFrame: During apnea period (until end-point is met or max. 15 or 30 minutes)
measure: Change in PaO2 in kPa
timeFrame: During apnea period (until end-point is met or max. 15 or 30 minutes)
measure: Change in cardiac output in L/min
timeFrame: During apnea period (until end-point is met or max. 15 or 30 minutes)
measure: Change in cerebral perfusion in %
timeFrame: During apnea period (until end-point is met or max. 15 or 30 minutes)
measure: Changes in end-expiratory lung impedance
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
measure: Change in invasive blood pressure
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
measure: Standard monitoring
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
measure: Depth of anaesthesia
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
measure: Bilateral brain oxygenation
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Arterial blood gas analyses
timeFrame: At 0, 1, 3, 5, 7, 9, 11, 13 and 15 minutes of apnoea or 0,1,3,5,7,9,13,15,17,19,21,23,25,27,29 and 30 min of apnoea.
measure: Postoperative questionnaire
timeFrame: Morning of first postoperative day
measure: Standard monitoring
timeFrame: During apnoea time (until end-point is met or max. 15 or 30 minutes)
Other outcomes:
Locations:
city: Bern
country: Switzerland
facility: University Hospital Inselspital
Study officials:
affiliation: University hospital of Bern
name: Lorenz Theiler, PD MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Patel A, Nouraei SA. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia. 2015 Mar;70(3):323-9. doi: 10.1111/anae.12923. Epub 2014 Nov 10.
citation: Gustafsson IM, Lodenius A, Tunelli J, Ullman J, Jonsson Fagerlund M. Apnoeic oxygenation in adults under general anaesthesia using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) - a physiological study. Br J Anaesth. 2017 Apr 1;118(4):610-617. doi: 10.1093/bja/aex036.
citation: Riedel T, Burgi F, Greif R, Kaiser H, Riva T, Theiler L, Nabecker S. Changes in lung volume estimated by electrical impedance tomography during apnea and high-flow nasal oxygenation: A single-center randomized controlled trial. PLoS One. 2022 Sep 28;17(9):e0273120. doi: 10.1371/journal.pone.0273120. eCollection 2022.
citation: Theiler L, Schneeberg F, Riedel T, Kaiser H, Riva T, Greif R. Apnoeic oxygenation with nasal cannula oxygen at different flow rates in anaesthetised patients: a study protocol for a non-inferiority randomised controlled trial. BMJ Open. 2019 Jul 11;9(7):e025442. doi: 10.1136/bmjopen-2018-025442.