An Algorithmic Approach to Preoxygenation

Pamukkale University

Status: Completed

Conditions: Anaesthesia Induction; Preoxygenation; Non-invasive Positive Pressure Ventilation

Treatments: Procedure: Group PSV+PEEP; Procedure: Group TVB; Procedure: Group PSV

Study type: Interventional

Funder types: Other

Identifiers

NCT06736197

PamukkaleUCTanriverdi-001

Details and patient eligibility

About

The aim of this randomized controlled trial is to evaluate an algorithmic approach to gradually adding pressure-supported ventilation and end-tidal positive pressure when conventional tidal volume breathing is insufficient for adequate preoxygenation. The main question it aims to answer is:

• Will the proportion of patients receiving preoxygenation increase?
• Will the duration of preoxygenation decrease?

Participants will;

• 200 patients who were planned to undergo general anesthesia for elective surgeries
• aged between 18 and 65 years
• ASA 1-2 physical status
• ETO2 <90% at the end of the 3rd minute with spontaneous tidal volume breathing

Full description

The patients were randomly assigned to one of two groups (Group TVB and Group PSV) according to a computer-generated randomisation table. In the patients included in Group TVB, the tidal volume breathing was maintained for a further two minutes. Group PSV received inspiratory pressure support of 6 cm H2O for +1 min. At the end of four minutes, patients whose ETO₂ value had not reached a minimum of 90% were randomly divided once more into two groups. One group continued with PSV, while the other was administered 4 cm H₂O PEEP in addition to PSV (Group PSV+PEEP).

When adequate preoxygenation was achieved, the duration of preoxygenation, SpO2, end-tidal carbon dioxide (ETCO2), arterial blood pressures and heart rate values were recorded. Any adverse effects such as discomfort or gastric distension were noted.

Enrollment: 378 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Elective surgeries general anaesthesia was planned for a patient aged 18-65 years with ASA 1-2 physical condition.

Exclusion criteria

• Haemodynamically unstable, preoperative oxygen support such as increased intracranial or intraocular pressure, to be operated on by thoracic surgery have conditions in which positive pressure ventilation may be indirectly harmful, BMI≥35 kg/m2, pregnant, undergoing emergency surgery and causing leakage in mask ventilation bearded male patients were not included in the study.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

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378 participants in 3 patient groups

Group TVB

Experimental group

Description:

Group TVB patients who could not reach 90% ETO2 at the end of the 3rd minute were continued with tidal volume breathing.

Treatment:

Procedure: Group TVB

Group PSV

Experimental group

Description:

Group PSV received 6 cm H2O positive pressure ventilation.

Treatment:

Procedure: Group PSV

Group PSV+PEEP

Experimental group

Description:

In addition to 6 cmH2O pressure support, 4 cmH2O end-expiratory positive pressure support was added to the patients included in Group PEEP.

Treatment:

Procedure: Group PSV

Procedure: Group PSV+PEEP