Electrical Impedance Tomography (EIT)

This study investigates if single lung ventilation on cardiopulmonary bypass can mitigate postoperative lung water accumulation determined by lung ultrasound in the ventilated lung as compared to the non-ventilated lung in patients at high-risk for developing severe pulmonary complications after cardiac surgery.

Babies born early (under 32 weeks) are at risk of developing lung problems after birth. A major reason for this is that the lungs are not fully developed. Lungs of preterm babies will often collapse in between breathing due to lung immaturity. Applying gentle pressure, using nasal device through their nostril or through the breathing tube helps to prevent this lung collapse. This would help in air-oxygen going to lungs and also makes the babies breathing more comfortable. This gentle pressure is medically called as PEEP/CPAP and could be delivered by breathing machine (ventilator) and CPAP machine, collectively called as "continuous distending pressure (CDP)". Those babies breathing on their own and receiving inadequate CDP would need more breathing support by placing them on breathing machine (ventilator). The longer the baby receives breathing machine support, higher chance of lung injury . Preterm infants who are already on breathing machine, providing sub optimal PEEP/CPAP could also lead to lung damage. Providing optimal PEEP/CPAP could prevent these negative outcomes. Currently there is not enough evidence to suggest optimal PEEP/CPAP in preterm infants. Neonatal units all around the world uses PEEP/CPAP ranging from 4 to 10cm H20 based on their unit practice. Currently available investigations provide limited one time information (e.g. Chest X-ray) regarding whether baby is receiving optimal PEEP/CPAP. Electrical Impedance Tomography (EIT) is a new technology which could provide better information regarding the pressure delivered. Also, this device would provide continuous information as if the clinicians are doing continuous chest X-ray but without any radiation. In this study, the team will assess the effect of different levels of PEEP/CPAP (4 to 10cm H20) on prevention of lung collapse using EIT. This would be studied in premature infants who are on breathing machine support and CPAP machine support.

Although the theoretical model of "cyclic on-off switching of pulmonary blood flow" provides a crucial perspective for understanding VILI, its clinical validation and real-time intervention face significant obstacles. The fundamental reason lies in the lack of pulmonary microcirculation monitoring technology capable of bedside, non-invasive, continuous operation with sufficient spatiotemporal resolution. Nowadays, a novel 3D-EIT can perform real-time and non-invasive assessment of the distribution of pulmonary blood flow. However, if 3D-EIT can help to identify "cyclic on-off switching of pulmonary blood flow" is still unclear.

This study is a prospective, single-center, single-blind, randomized controlled clinical trial. Patients scheduled for laparoscopic bariatric surgery will be selected and randomly assigned to either the EIT-guided individualized PEEP group (Group P-eit) or the control group (Group P-8). Group P will be ventilated using the PEEP value determined by EIT, while Group C will be ventilated with a fixed PEEP value of 8 cmH2O.The primary outcome is the incidence of postoperative pulmonary complications (PPCs) within 72 hours after surgery.

Electrical Impedance Tomography (EIT) is a non-invasive, radiation-free, bedside imaging technique that has been in clinical use for over three decades (1). It is primarily utilized to monitor regional lung ventilation in mechanically ventilated patients. In recent years, EIT has become a routine tool in critical care settings due to its capacity to provide real-time, bedside insights into pulmonary function. Its applications are diverse, ranging from support during non-invasive ventilation and endotracheal intubation (2) to the management of complex cases of mechanical ventilation. One of its key advantages lies in guiding the optimization of Positive End-Expiratory Pressure (PEEP) titration, which may help tailor ventilatory support to individual patients and potentially reduce the mechanical power delivered to the lungs(3,4). Despite these benefits, current evidence does not conclusively demonstrate a reduction in mortality associated with the use of EIT in critical care (5,6). Nevertheless, EIT shows promise in several emerging areas, such as monitoring ventilation distribution during prone positioning - even in awake, non-intubated patients (7) - and in the early detection of atelectasis under various clinical conditions (8). Recently, advancements in EIT technology have led to the development of new models capable of assessing pulmonary "pulsatility," thereby expanding the potential clinical applications of EIT beyond traditional ventilation monitoring. This feature may facilitate the bedside detection of conditions such as atelectasis, pneumonia, pleural effusion, and even pulmonary embolism (9,10). In this context, the Intensive Care Unit at Erasme Hospital is acquiring two EIT devices to enhance diagnostic capabilities and improve the care of patients requiring either non-invasive or invasive ventilation during their ICU stay. To support the systematic implementation of these devices and enable future research, it is necessary to establish a registry documenting their clinical use within the ICU. This registry will serve as a foundation for tracking usage patterns, evaluating outcomes, and potentially contributing to future scientific studies. Standard ICU data such as SOFA scores and SAPS II will be recorded, as is already routinely done in some registries like Epimed. This registry will be specific to the Erasme ICU and will collect detailed data on ventilation parameters, EIT measurements, and recruitment maneuvers in patients undergoing mechanical ventilation-whether invasive or non-invasive-when the clinical team determines that a recruitment maneuver is indicated and chooses to use an EIT device for monitoring. Data will be entered into RedCap by the attending physicians or physiotherapists responsible for the patient. Data collection will be prospective, as it is not technically possible to automatically synchronize the recording of ventilation parameters and EIT measurements using the existing software systems. There are no expected risks for the patients, as the procedures involved are considered standard practice in intensive care settings. Patients may benefit from the collection of these data, as it allows for closer monitoring of ventilation parameters during their ICU stay. As this is a registry-based study, there will be no predefined duration or fixed number of patients. However, we estimate data will be recorded over a five-year period, with an inclusion of at least 300 patients per year. Inclusion Criteria for ICU Patients: * Patient aged more than 12 years old (no pediatric EIT belt) * Patient monitored by an EIT belt OR Patient undergoing a recruitment maneuver OR Patient undergoing prone position.

The application of electrical impedance tomography (EIT) in intensive care is increasing. It can provide additional information on individual respiratory physiology of patients, enabling clinicians or respiratory therapists to monitor patients' respiratory responses to different ventilator settings, respiratory treatment methods or clinical evolution, and thus achieve more personalized mechanical ventilation methods. Although this technology provides a large amount of valuable information, there is still uncertainty about how to use it and interpret the results in critically ill patients. Therefore, the evidence that EIT-guided ventilation strategies can improve prognosis is still in its infancy. Through this survey, the investigators aim to understand the current experiences and guiding roles of EIT in clinical practice. The secondary objective is to learn about the current challenges of EIT in clinical and practical settings, as well as the factors that promote or hinder the implementation of EIT monitoring technology.

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.

Acute respiratory distress syndrome (ARDS) in its moderate to severe forms is associated with high mortality. Mechanical ventilation (MV) remains the cornerstone of ARDS management but carries a significant risk of ventilator-induced lung injury (VILI). Positive end-expiratory pressure (PEEP), a fundamental component of MV, is widely utilized in clinical practice; however, optimal PEEP selection for patients with moderate to severe ARDS remains a complex and unresolved challenge. Electrical impedance tomography (EIT), a bedside imaging modality that evaluates regional ventilation distribution, offers a means of individualizing PEEP settings in mechanically ventilated patients. By balancing the competing risks of alveolar overdistension and collapse, EIT facilitates precision in PEEP titration. This study compares the impact of EIT-guided PEEP selection versus the conventional low FiO2-PEEP table on blood oxygenation and pulmonary mechanics.