Is exhaled propofol concentration influenced by mechanical ventilation settings?

JRCT ID: jRCT1032230398

Registered date:16/10/2023

Basic Information

• Recruitment status: Pending
• Health condition(s) or Problem(s) studied: Elective surgical procedure
• Date of first enrollment: 16/10/2023
• Target sample size: 30
• Study type: Interventional

Intervention(s)

1. Selection of anesthesia method (total intravenous anesthesia with propofol)
2. Mechanical ventilator settings during surgery

Outcome(s)

• Primary Outcome: Prediction Error (PEex) calculated using estimated end tidal expiratory propofol concentration and measured plasma propofol. PEex is defined as (measured plasma propofol concentration - end tidal propofol concentration)/end tidal propofol concentration or measured plasma propofol concentration/end tidal propofol concentration.

Secondary Outcome

The PEex derivatives, pharmacokinetic indices median prediction error (MDPE) and median absolute prediction error (MDAPE), are used to assess the performance of end tidal propofol concentration as a predicted value of plasma propofol concentration. If respiratory conditions influence prediction error, prediction formula will be developed to improve the predictive performance of plasma propofol concentrations using end tidal propofol concentration. The time course of PEex is illustrated.
Prediction error of measured plasma propofol concentration vs predicted plasma propofol concentration is calculated as (measured plasma propofol concentration-predicted plasma propofol concentration)/predicted plasma propofol concentration, or as measured plasma propofol concentration/predicted plasma propofol
concentration. MDPE and MDAPE are also calculated using predicted plasma concentartion determined using the Marsh model. The time course of the prediction error is dipicted.
The end tidal propofol concentration and predicted plasma propofol concentration as predictive values of measured plasma propofol vconcentration are compared.

Key inclusion & exclusion criteria

• Age minimum: >= 18age old
• Age maximum: Not applicable
• Gender: Both

Include criteria

1) 30 scheduled surgery patients aged 18 and over who are hospitalized at Yokohama City University
Hospital (10 aged 18-49, 10 aged 50-69, 10 aged 70 and over. 5 males and 5 females in each age group)
2) Patients who are expected to undergo general anesthesia for more than 3 hours
3) Supine position, general anesthesia patient under double lung ventilation
4) Patients undergoing invasive arterial pressure catheter insertion
5) Patients who have given their written consent to participate in this study

Exclude criteria

1) Patients contraindicated for administration of propofol
2) Patients whose ASA classification, which is the general condition classification of the American Society of Anesthesiologists, is class 4 or higher
3) Surgery with head low or high at 25 degrees or more
4) Patients with interstitial pneumonia, COPD, pulmonary edema, severe cardiac dysfunction, severe liver
dysfunction
5) Pregnant women (lactating women)

Related Information

• Primary Sponsor: Masui Kenichi