EIT-Guided Ventilator Settings in AHRF

Using Electrical Impedance Tomography-Guided Ventilator Settings to Reduce Mechanical Power in Acute Hypoxemic Respiratory Failure : An Exploratory Study

This exploratory study aims to investigate the effect of Electrical Impedance Tomography (EIT)-guided ventilator settings on mechanical power in patients with acute hypoxemic respiratory failure (AHRF), including both ARDS and non-ARDS conditions. Mechanical power, a key factor associated with ventilator-induced lung injury (VILI), will be measured before and after EIT-guided PEEP titration. The study will evaluate feasibility and changes in lung mechanics, gas exchange, and EIT parameters. A total of 17 patients requiring invasive mechanical ventilation will be enrolled at Siriraj Hospital, Mahidol University.

Study Overview

• Status: Recruiting
• Conditions: Acute Respiratory Distress Syndrome (ARDS); Acute Hypoxemic Respiratory Failure; Ventilator Induced Lung Injury; Mechanical Power; Electrical Impedance Tomography (EIT)
• Intervention / Treatment: Device: Electrical Impedance Tomography (EIT), Enlight 2100

Detailed Description

This exploratory study investigates the effect of Electrical Impedance Tomography (EIT)-guided PEEP titration on mechanical power in patients with acute hypoxemic respiratory failure (AHRF), including both ARDS and non-ARDS conditions such as severe pneumonia and pulmonary edema. Mechanical power represents the energy transferred from the ventilator to the respiratory system per unit time and has been associated with the development of ventilator-induced lung injury (VILI).

Patients who meet the inclusion criteria will undergo a standardized EIT-guided PEEP titration protocol using the Enlight 2100 EIT device. Optimal PEEP is defined as the PEEP level that minimizes both alveolar overdistension and collapse based on real-time EIT measurements. Mechanical power and other ventilatory parameters (lung compliance, plateau pressure, driving pressure, 4∆P x RR index, and gas exchange) will be assessed before and after PEEP titration at predefined time points (baseline, 2, 12, and 24 hours).

The study also evaluates the regional ventilation distribution ratios, as well as safety outcomes including hemodynamic instability, arrhythmias, and pneumothorax. Patients will be followed for up to 28 days to record duration of mechanical ventilation, ICU stay, and 28-day mortality.

This study aims to assess the feasibility and physiological benefits of personalized ventilator settings using EIT in critically ill patients with AHRF and to generate preliminary data for future interventional studies.

• Study Type: Interventional
• Enrollment (Estimated): 17
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jitanong Sootlek, MD, PCCM; Phone Number: +66954164563; Email: jitanong9651@gmail.com
• Study Contact Backup: Name: Ranistha Ratanarat, MD, Nephrology, Critical care; Phone Number: +66896685287; Email: ranittha@gmail.com

Study Locations

• Thailand
  • Bangkok, Thailand, 10700
    • Recruiting
    • Siriraj Hospital, Mahidol University
    • Contact: Ranistha Ratanarat, MD, Nephrology, Critical care; Phone Number: +66896685287; Email: ranittha@gmail.com
    • Principal Investigator: Ranistha Ratanarat, MD, Nephrology, Critical care

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosed with acute hypoxemic respiratory failure within 48 hours
• Expected to require invasive mechanical ventilation ≥ 48 hours
• On mechanical ventilation within 24 hours
• Deep sedation and neuromuscular blockade

Exclusion Criteria:

• Pregnancy
• Body mass index (BMI) > 40 kg/m2
• Contraindications to using electrical impedance tomography, including
• Presence of a pacemaker or automatic implantable cardioverter-defibrillator (AICD)
• Inability to place the belt due to presence of surgical wounds dressing, thoracic or spinal cord trauma, recent thoracic surgery, etc.
• High risk for PEEP titration
• Hemodynamic instability defined as mean arterial pressure < 65 mmHg despite optimization of fluid status and/or use of vasopressors
• Unstable cardiac arrhythmias
• Presence of lung bullae greater than 2 cm in diameter, identified on chest X-ray
• Presence of pneumothorax or pneumomediastinum
• Right-sided heart failure or severe pulmonary hypertension
• Neurologic conditions associated with a risk of intracranial hypertension
• Use of extracorporeal membrane oxygenation (ECMO)
• Severe chronic respiratory disease, defined as follows: requiring home oxygen therapy, or previous lung function showing (FEV1 less than 20 ml/kg PBW, or FEV1/FVC less than 50% predicted value), or chronic hypercapnia (PaCO2 greater than 45 mmHg) and/or chronic hypoxemia (PaO2 less than 55 mmHg) on FIO2 = 0.21, or radiographic x-ray evidence of any chronic over-inflation or chronic interstitial infiltration, or chronic restrictive, obstructive, neuromuscular, chest wall or pulmonary vascular disease resulting in severe exercise restriction (unable to climb stairs or perform household duties, secondary polycythemia, severe pulmonary hypertension with mean pulmonary arterial pressure greater than 40 mmHg)
• Decision to withhold life-sustaining treatment or palliative care.
• Moribund status with an expected survival of less than 24 hours.
• Refusal to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EIT-guided PEEP titration; Patients will undergo ventilator adjustments using EIT-guided PEEP titration to optimize mechanical power and lung mechanics.	Device: Electrical Impedance Tomography (EIT), Enlight 2100; Patients will undergo ventilator adjustments using EIT-guided PEEP titration to optimize mechanical power and lung mechanics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Mechanical Power	Mechanical power (MP) will be calculated using Gattinoni's simplified formula. Simplified Gattinoni's formula: MP = 0.098 × respiratory rate × tidal volume × [peak inspiratory pressure - (plateau pressure - PEEP)/2] calculated mechanical power (measured in J/min) before and after using EIT-guided PEEP titration in patients with acute hypoxemic respiratory failure. Unit of Measure: Joules per minute (J/min)	ฺBaseline and 2 hours after EIT-guided ventilator adjustment and follow-up over 24 hours (baseline, 2 hours, 12 hours, and 24 hours after EIT-guided ventilator adjustment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in PEEP level	Positive End-Expiratory Pressure (PEEP) level before and after EIT-guided ventilator adjustment. Unit of Measure: cmH₂O	At baseline and then 2 hours, 12 hours, 24 hours after EIT-guided PEEP titration
Change in Respiratory Static Compliance	calculate static respiratory compliance (tidal volume/driving pressure) before and after EIT-guided PEEP titration Unit of Measure: mL/cmH₂O	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in Driving Pressure	calculate driving pressure (plateau pressure - PEEP) following EIT-guided PEEP titration. Unit of Measure: cmH₂O	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in Plateau Pressure	measure plateau pressure before and after EIT-guided PEEP titration.	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in 4∆P + RR Index	Calculated value of 4 x Driving Pressure + Respiratory Rate before and after EIT-guided PEEP titration. Unit of Measure: Joules per minute (J/min)	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in Elastic dynamic power	calculate elastic dynamic power formula : elastic dynamic power = 0.098 x respiratory rate x tidal volume x 0.5 x driving pressure before and following EIT-guided PEEP titration Unit of Measure: Joules per minute (J/min)	Baseline, 2 hours, 12 hours, and 24 hours after intervention
change in elastic static power	calculated value of elastic static power = 0.098 x respiratory rate x tidal volume x PEEP before and after EIT-guided PEEP titration Unit of Measure: Joules per minute (J/min)	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in resistive power	calculated resistive power = 0.098 x respiratory rate x tidal volume x (peak inspiratory pressure - plateau pressure) before and after EIT-guided PEEP titration Unit of Measure: Joules per minute (J/min)	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in arterial oxygen tension (PaO₂)	Arterial oxygen tension (PaO₂) measured by arterial blood gas analysis before and after EIT-guided PEEP titration. Unit of Measure: PaO₂: mmHg	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Ventilation distribution ratio	record anterior/posterior and right/left ventilation distribution from EIT before and after EIT-guided PEEP titration Unit of Measure: Percentage (%)	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Incidence of complication	Number of patients experiencing adverse events related to EIT or ventilator adjustments, including pneumothorax, hemodynamic instability, or arrhythmia. Unit of Measure: Number of participants with event	Up to 24 hours after intervention
Change in arterial carbon dioxide tension (PaCO₂)	Carbon dioxide tension (PaCO₂) measured by arterial blood gas analysis before and after EIT-guided PEEP titration. Unit of Measure: PaCO₂: mmHg	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in arterial pH	Arterial pH measured by arterial blood gas analysis before and after EIT-guided PEEP titration. Unit of Measure: pH: unitless	Baseline, 2 hours, 12 hours, and 24 hours after intervention
Change in PaO₂/FiO₂ ratio	PaO₂/FiO₂ ratio changes before and after EIT-guided PEEP titration. PaO₂/FiO₂ ratio will be calculated using PaO₂ from arterial blood gas and FiO₂ obtained from ventilator settings. Unit of Measure: PaO₂/FiO₂: mmHg	Baseline, 2 hours, 12 hours, and 24 hours after intervention

Collaborators and Investigators

• Sponsor: Mahidol University
• Investigators: Principal Investigator: Ranistha Ratanarat, Associated Professor, MD, Siriraj Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 17, 2024
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: March 26, 2025
• First Submitted That Met QC Criteria: April 17, 2025
• First Posted (Actual): April 20, 2025

Study Record Updates

• Last Update Posted (Actual): April 27, 2025
• Last Update Submitted That Met QC Criteria: April 22, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Acute Hypoxemic Respiratory Failure; Electrical Impedance Tomography; Mechanical Power, Ventilator-induced lung injury
• Additional Relevant MeSH Terms: Wounds and Injuries; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Infant, Premature, Diseases; Infant, Newborn, Diseases; Thoracic Injuries; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn; Respiratory Insufficiency; Lung Injury; Ventilator-Induced Lung Injury; Acute Lung Injury
• Other Study ID Numbers: SI 962/2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: This study does not plan to share individual participant data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No