Prevention of Hypoxemia and Hypercarbonemia by High Flow Nasal Cannula Respiratory Management during Fiber Intubation in Patients with Difficult Intubation

JRCT ID: jRCTs072240110

Registered date:10/02/2025

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Oral Maxillo Facial Surgery
• Date of first enrollment: 10/02/2025
• Target sample size: 20
• Study type: Interventional

Intervention(s)

After extubation, study subjects will be randomly assigned to receive respiratory management by low-flow oxygen administration (3 L/min: FiO2 0.32) using THIRIVE (LFNC group) or by inhalation of heated and humidified air-oxygen mixture (FiO2 0.32) at a flow rate of 30 L/min (HFNC group) through a dedicated cannula inserted with THRIVE, an HFNC device, after postoperative extubation. (3L/min: FiO2 0.32) using THRIVE.

Patients in both groups are placed supine on the operating table before the start of anesthesia, and in addition to the usual patient monitoring monitors such as transcutaneous oxygen saturation, electrocardiogram, and non-invasive blood pressure monitor, a sensor for EIT is placed on the patient's chest.
EIT is measured continuously from before induction of anesthesia. values immediately before induction of anesthesia, during anesthesia and just before the start of surgery (artificial respiration plus PEEP 5 cmH2O, at the end of surgery and before awakening from anesthesia, immediately after extubation before HFNC and LFNC are attached and use begins, and immediately after extubation (10 minutes after HFNC and LFNC use begins) without being affected by other operations at each point (See Table1). After returning to the general ward, continuous measurements will be made up to 3 hours after returning continuously by the sensors of the EIT fitted. In particular, values immediately after return, at 1 hour, and at 3 hours after return will be taken without influence of other operations. For respiratory management, a dedicated nasal cannula (Duet optiflow) of the THRIVE, an HFNC device, is placed in the nose immediately after extubation to administer a high-flow oxygen/air mixture (FiO2 0.32) at 30 L/min, while the LFNC group is administered a heating device through a nasal cannula (Optiflow) using the same THRIVE device. The LFNC group inhaled a heated and humidified air-oxygen mixture (FiO2 0.32) at a low flow rate of 3 L/min through a nasal cannula (Optiflow) using the same device, THRIVE.

Both groups will be monitored for lung recruitment effects by assessing regional lung ventilation distribution and alveolar air content until 3 hours after return to the general ward. Monitoring of lung recruitment effects will be evaluated using EIT in four ventral to dorsal horizontal regions of interest (ROIs 1, 2, 3, and 4) divided equally. The ROX index (=SpO2/FiO2/respiratory rate) will be calculated later from the data (SpO2, respiratory rate, and oxygenation) collected continuously using AIRVO3.
If transcutaneous oxygen saturation drops below 90% postoperatively, oxygenation (FiO2) is increased to ensure safe respiratory management.

Outcome(s)

• Primary Outcome: Percentage of hypoxemia (<90%) by SaO2 (arterial blood oxygen saturation)

Secondary Outcome

(i)Compare the percentage of hypoxemia (less than 60 mmHg) from PaO2 (arterial blood partial pressure of oxygen)
(ii)Compare the rate of occurrence of hypercarbonemia (>50 mmHg) from PaCO2 (arterial blood carbon dioxide partial pressure).
(iii)Percentage change in acid-base equilibrium from HCO3- (bicarbonate ion), pH, BE

Key inclusion & exclusion criteria

• Age minimum: >= 18age old
• Age maximum: < 85age old
• Gender: Both

Include criteria

(i) Patients who are judged to require nasotracheal intubation with fiber for oral surgery
(ii) Patients who meet any of the following criteria
Severe morbid obesity (BMI >35)
Difficulty in intubation due to cervical cellulitis
Abnormal mandibular morphology (including micrognathia and postoperative jaw deformity)
Cervical retroversion disorder such as indirect rheumatism and spondylolisthesis
Severe mouth opening disorder that makes the use of a videolaryngoscope impossible.
(iii)Patients who are at least 18 years old and less than 85 years old at the time of consent
(iv) Patients who have received sufficient explanation of their participation in this study, and who have given written consent of their own free will based on sufficient understanding.

Exclude criteria

(i)Patients without spontaneous respiration
(ii)Patients using artificial nose
(iii)Patients who are participating in a clinical trial or other clinical research
(iv)Patients who are deemed inappropriate as research subjects by the principal investigator

Related Information

• Primary Sponsor: Kurata Shinji
• Secondary Sponsor: Fisher & Paykel Healthcare Limited