Comparison of Physiological Effects of Two High-Flow Tracheal Oxygen Versus T-Piece During Spontaneous Breathing Trials

Jian-Xin Zhou

Status: Enrolling

Conditions: Critical Care; Oxygen Therapy; Mechanical Ventilation

Treatments: Procedure: Standard high flow tracheal oxygen-40L/min; Procedure: Modified high flow tracheal oxygen-40L/min; Procedure: Standard high-flow tracheal oxygen-60 L/min; Procedure: T-piece; Procedure: Modified high-flow tracheal oxygen-60L/min

Study type: Interventional

Funder types: Other

Identifiers

NCT06816706

IIT2024-157-002

Details and patient eligibility

About

Spontaneous breathing trials (SBT) are essential for assessing extubation tolerance, yet optimal approaches are debated. High-flow nasal oxygen offers benefits like precise oxygen delivery, flow-related positive end-expiratory pressure generation and improved lung function. While high-flow tracheal oxygen can also be used as an SBT method, it has reduced physiological effects due to bypassing the upper airway with a more open circuit. To enhance this limitation, investigators developed a modified high-flow tracheal oxygen tube with a smaller expiratory end diameter to increase expiratory resistance and airway pressure. This is a prospective randomized crossover study that aims to compare the physiological effects of standard and modified high-flow tracheal oxygen versus T-piece during SBT.

Full description

A spontaneous breathing trial (SBT) is a crucial step in the weaning and extubation process for assessing extubation tolerance. However, the optimal approach for conducting SBTs remains a topic of debate.

High-flow nasal oxygen has been shown to provide several physiological benefits, including precise control of the fraction of inspired oxygen, generation of flow-related positive end-expiratory pressure, increased end-expiratory lung volume, improved oxygenation, and enhanced carbon dioxide elimination. High-flow oxygen therapy can also be applied via an artificial airway as high-flow tracheal oxygen. Previous studies have identified this therapy as a potential alternative for SBTs. However, compared to high-flow nasal oxygen, high-flow tracheal oxygen exhibits significantly diminished physiological effects due to the bypassing of the narrow nasopharynx, glottis, and upper airway as well as a more open circuit.

To address this limitation, the investigators have developed a modified high-flow tracheal oxygen tube with a reduced expiratory end tube diameter. This modification aims to create higher expiratory resistance and airway pressure, thereby simulating the physiological effects of HFNC. This study is a prospective randomized crossover physiological study designed to compare the effects of standard and modified high-flow tracheal oxygen versus T-piece during spontaneous breathing trials. Key physiological parameters will be assessed, including airway pressure, end-expiratory lung volume, vital signs, oxygenation, and respiratory workload.

Enrollment: 20 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Mechanical ventilation for more than 24 hours
2. Considered by the physicians for the readiness to wean and ready for spontaneous breathing trials

Exclusion criteria

1. Age younger than 18 years old
2. Pregnancy
3. Hemodynamic instability (mean arterial pressure <60 mmHg, heart rate >140 or <60 bpm)
4. Respiratory and oxygenation instability (respiratory rate > 35bpm or oxygen saturation measured by pulse oximetry <90%)
5. Neuromuscular diseases or phrenic nerve injury
6. Recent trauma or surgery to the trachea, esophagus, neck, chest, or stomach
7. Pneumothorax or placement of a chest drainage
8. Contraindication to electrical impedance tomography (EIT) (implantable defibrillator)
9. Anticipating withdrawal of life support

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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20 participants in 5 patient groups

Modified high flow tracheal oxygen-40L/min

Experimental group

Description:

Modified high-flow tracheal oxygen with a flow rate of 40L/min will be performed in mechanically ventilated patients undergoing spontaneous breathing trials.

Treatment:

Procedure: Modified high flow tracheal oxygen-40L/min

Standard high flow tracheal oxygen-40L/min

Experimental group

Description:

Standard high-flow tracheal oxygen with a flow rate of 40L/min will be performed in mechanically ventilated patients undergoing spontaneous breathing trials.

Treatment:

Procedure: Standard high flow tracheal oxygen-40L/min

T-piece

Experimental group

Description:

T-piece will be performed in mechanically ventilated patients undergoing spontaneous breathing trials.

Treatment:

Procedure: T-piece

Modified high-flow tracheal oxygen-60L/min

Experimental group

Description:

Modified high-flow tracheal oxygen with a flow rate of 60L/min will be performed in mechanically ventilated patients undergoing spontaneous breathing trials.

Treatment:

Procedure: Modified high-flow tracheal oxygen-60L/min

Standard high-flow tracheal oxygen-60L/min

Experimental group

Description:

Standard high-flow tracheal oxygen with a flow rate of 60L/min will be performed in mechanically ventilated patients undergoing spontaneous breathing trials.

Treatment:

Procedure: Standard high-flow tracheal oxygen-60 L/min