Clinical Trial Details
— Status: Terminated
Administrative data
| NCT number |
NCT05234424 |
| Other study ID # |
Frykholm2201 |
| Secondary ID |
|
| Status |
Terminated |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 8, 2022 |
| Est. completion date |
May 13, 2024 |
Study information
| Verified date |
May 2024 |
| Source |
Uppsala University Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Apneic oxygenation describes the process of continuous oxygenation of the blood without
breathing efforts. This anesthesia technique has been described in the literature for more
than 100 years and is sometimes used under general anesthesia, e.g. during surgery of the
vocal chords. Although this technique usually provides marked prolongation of the apneic
period because of excellent oxygenation, it is limited by the absence of ventilation and the
corresponding accumulation of carbon dioxide in the blood. This will lead to worsening
respiratory acidosis and associated complications, such as cardiac arrythmias.
In 2015 it was reported that apneic oxygenation with high-flow nasal oxygen delivery systems
(HFNO), a device that provides heated humidified oxygen at high flow rates (usually 30-70
L/min), resulted in less carbon dioxide accumulation compared with historical controls. This
specific technique of apneic oxygenation was termed transnasal humidified rapid-insufflation
ventilation exchange (THRIVE). To date, the impact on different flow rates on blood carbon
dioxide accumulation during THRIVE is unknown. Specifically, very high flow rates, exceeding
70 L/min have not been investigated. Therefore, the aim of this trial is therefore to study
the rate of accumulation of carbon dioxide during THRIVE at two different flow rates: 40 and
100 L/min.
Description:
Eligible participants with signed informed consent presenting for elective surgery will have
standard monitoring with ECG, pulse oximetry, blood pressure, train-of-four monitoring and
capnography applied at arrival to the operating room. In addition, a circumferential electric
impedance tomography thoracic elastic band with equally spaced electrodes will be placed in
the 4th to 6th intercostal space. After induction of general anesthesia with a target
controlled infusion of Propofol+Remifentanil and muscle relaxation with Rocuronium bromide,
adequate face mask ventilation will be confirmed and arterial cannulation will be performed.
Patients will thereafter receive THRIVE at two flow rates for 10 minutes each in a randomized
order. During THRIVE, video laryngoscopy will be performed with a grade 2B visualization of
the larynx to establish similar airway patency during the interventions.
Before each flow, an end-tidal oxygen value of >0.85 and end-tidal carbon dioxide value of
4.5-5.0 kPa is achieved by controlled pressure regulated volume control ventilation to
establish similar arterial partial pressure of oxygen and carbon dioxide at baseline. An
arterial blood gas will also be analyzed before the start of each flow rate to ensure that
the initial pCO2 is less than 6.0 kPa. Furthermore, a standardized lung recruitment maneuver
will be performed to establish similar baseline compliance of the respiratory system.
Termination criteria will be:
- All flow rates have been applied.
- Severe acidemia (pH<7.10), hypercapnia (pCO2>11.0) or desaturation to SpO2 less than 90%
for more than 10 seconds. These termination criteria will apply only to the current flow
rate being tested. The participant will be mask ventilated until baseline parameters are
established and the next THRIVE flow rate according to randomization will be applied.
