The objective of this research is to utilize respiratory effort parameters as a tool to assist in adjusting sedative drug levels for patients undergoing mechanical ventilation in the intensive care unit, in comparison to the conventional usual care approach.

The research investigators conduct daily screening for new participation in the intensive care unit and semi-intensive care unit, selecting individuals based on inclusion and exclusion criteria. In cases where patients require sedative drugs before the research investigators assessment, such as when patients are agitated or have difficulty asynchrony, standard sedative dosages are allowed in emergency rooms and the intensive care unit.

• Informed consent for participation in the research is obtained from direct relatives of participants, accompanied by an explanation of the research procedures, methods, and potential complications. Relatives are required to sign the consent form as the primary decision-makers, considering the participants may be in an altered state of awareness and decision-making capacity.
• Participants meeting the inclusion and exclusion criteria are registered for the research project and assigned a participant identification code. They are divided into two groups: one receiving the intervention involving the measurement of respiratory effort using P0.1 and Pocc then calculating to dynamic transpulmonary pressure swing (Predicted ΔPL) to adjust sedative drugs, and the other, serving as the control group, receives usual care adjustments made by the ward physicians' decision. The randomization process is facilitated by a third party.

The randomization involves creating equally distributed tokens for both groups (1:1 ratio), with the total number (n) representing the population to be included in the study. These tokens are placed in a random box for the randomization process. The basic information of research participants, laboratory, and mechanical ventilator parameters will be collected.

Inclusion Criteria:

1. Participants must be aged between 18-75 years.

2. Admitted to the critical care and semi-critical care units (ICUs) of the Department of Internal Medicine, Ramathibodi Hospital (ICUs 9IC, 8IK, and 7NW).

3. Patients with acute respiratory failure admitted to the hospital with the following conditions within the first 48 hours:

   • PaO2/FiO2 greater than 150 or
   • PaO2 less than 60 mm Hg or
   • SaO2 less than 90 mm Hg or
   • Work of breathing more than 25 breaths per minute or requiring respiratory muscle assistance

4. Permission obtained from the attending physician.

5. Research participants or their direct relatives must sign informed consent.

6. The research can commence and data can be recorded within 48 hours after the patient has received treatment with the mechanical ventilator.

7. Indicate for receiving sedative drugs during an invasive mechanical ventilator include situations such as when the patient experiences pain or agitation after the placement of the breathing assistance device or when there is patient-ventilator asynchrony.

Exclusion Criteria:

1. Admitted to the hospital or had a history of hospital admission within a month before recruitment.
2. History of cardiovascular or cerebrovascular events within the last 12 months.
3. Allergic to sedative drugs used in the study.
4. Pregnant.
5. Terminal-stage cancer patient, terminal illness-stage of disease who desire palliative care.
6. Active neurological or muscular disorders affecting stability.
7. Brain coma, brain death, or status epilepticus.
8. Severe mental health conditions, including active depression with psychotic features, bipolar disorder, or schizophrenia.
9. Uncontrolled thyroid conditions within a month before recruitment.
10. Uncorrectable patients with severe hypoxemia (P/F ratio less than 150).
11. Patients receiving neuromuscular blocking agents.

The entire final data results will be shared when the research has been published after a trial period of 2 years.