Clinical Research Directory

Effects of Periodic Recruitment Maneuvers on Atelectasis and Respiratory Mechanics During Elective Spine Surgery Assessed by Lung Ultrasonography

During general anesthesia, particularly in patients undergoing spine surgery in the prone (face-down) position, increased intrathoracic and abdominal pressure may reduce lung compliance and promote the development of atelectasis (partial lung collapse). Atelectasis can impair intraoperative oxygenation and may increase the risk of postoperative pulmonary complications. Alveolar recruitment maneuvers (ARM) are routinely used in anesthesia practice to reopen collapsed lung regions; however, it remains unclear whether periodic application of ARM throughout surgery provides additional benefit compared with standard single-time application. This prospective, randomized controlled clinical study aims to evaluate whether periodic alveolar recruitment maneuvers applied during elective spine surgery in the prone position reduce intraoperative atelectasis and improve respiratory mechanics compared with the standard approach of performing ARM only after positioning and before extubation. Adult patients undergoing elective spine surgery under general anesthesia will be randomly assigned to either a periodic ARM group or a standard ARM group. Lung aeration will be assessed using lung ultrasound, a non-invasive and radiation-free bedside imaging method. The primary outcome is the incidence of intraoperative atelectasis assessed before extubation. Secondary outcomes include lung ultrasound aeration scores, respiratory mechanics parameters (such as airway pressures and compliance), oxygenation indices, and the occurrence of transient intraoperative respiratory or hemodynamic events. The findings of this study may help optimize intraoperative ventilation strategies in prone spine surgery and contribute to improved perioperative respiratory safety.

The PRE-VAIL Study

During the prone position, there may be an increase in intragastric pressure. The investigators focus on a scientific question: Whether reducing enteral nutrition before the prone position will benefit patients with severe mechanically ventilated acute respiratory distress syndrome (ARDS). The experimental group had the enteral nutrition dose reduced before the prone position, while the control group did not have the enteral nutrition dose reduced

ORI-Guided FiO₂ Titration in Prone Spine Surgery: Impact on Postoperative Atelectasis Assessed by Lung Ultrasound

Atelectasis is a frequent pulmonary complication after general anesthesia, often triggered by preoxygenation and intraoperative hyperoxia. High inspiratory oxygen fractions (FiO₂) can promote absorption atelectasis, ventilation-perfusion mismatch, hemodynamic alterations, and oxidative injury. This study evaluates the effect of two intraoperative oxygen management strategies-oxygen reserve index (ORI)-guided FiO₂ titration versus fixed 50% FiO₂-on postoperative atelectasis in patients undergoing thoracolumbar spine surgery under general anesthesia. Atelectasis severity will be assessed using lung ultrasonography (LUS), scored across 12 thoracic regions (0-3 per region, total 0-36), while respiratory function changes will be examined via preoperative and 24-hour postoperative spirometry (FVC, FEV₁, FEV₁/FVC). Because postoperative spirometry may be influenced by pain, Numeric Rating Scale (NRS) scores will be recorded to help distinguish true restrictive patterns from pain-limited respiratory effort. The study aims to determine whether ORI-guided FiO₂ titration can reduce postoperative atelectasis and improve respiratory outcomes compared with a fixed FiO₂ approach.

Early Verticalization of the Patient With Acute Respiratory Distress Syndrome: Assessment of Feasibility and Safety.

Acute Respiratory Distress Syndrome (ARDS) is defined according to the Berlin definition (1) as diffuse lung damage occurring in patients with a predisposing risk factor. Positioning in the prone position (PP) has been shown to decrease mortality in patients with moderate to severe ARDS. However, this technique is not without deleterious effects such as ventilator-associated pneumonia, endotracheal tube obstruction, development of pressure ulcers, and increased workload for the caregivers. There are other positioning techniques such as the "upright" position, which simulates a relative verticality, which allows to increase the effects of the prone position and even in some patients to improve oxygenation without the PP in the acute phase of ARDS. However, given the revolution caused by the use of PP in ARDS patients, verticalization have not been studied in more details. Today, there is a bed on the market that allows patients to be truly upright without having to transfer them to a tilt table. The investigators believe that raising ARDS patients in the acute phase is safe and feasible in routine practice. In this research protocol comparing PP and verticalization in a crossover trial design in acute ARDS patients, the investigators want to show that this technique can be safe and feasible, with the same effects on oxygenation as PP.

Electrical Impendance Tomography Usage in ICU

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.

Hemodynamic Effects of Surgical Position in Prone vs. Supine Percutaneous Nephrolithotomy

This prospective, randomized controlled study evaluates the hemodynamic effects of prone and supine positions during percutaneous nephrolithotomy (PNL) for large kidney stones. Surgical position may influence intraoperative and postoperative hemodynamic stability. Prone positioning can increase intrathoracic pressure and reduce venous return, whereas supine positioning may provide greater hemodynamic stability. A total of 84 patients will be randomized to undergo PNL in prone or supine positions. Primary outcomes include changes in hemodynamic parameters during surgery. Results may guide surgical position selection, especially in patients with potential hemodynamic risk.

Measurement of Intraocular Pressure in Patients Undergoing Laminectomy in the Prone Position

Laminectomy surgeries, typically performed for lumbar disc herniation and spinal disorders, are often lengthy surgical procedures requiring patients to be in the prone position. While this position provides better visibility of the surgical field, it can lead to physiological changes in intraocular pressure (IOP) in anesthetized patients. An increase in IOP, though rare, has the potential to cause severe ocular complications such as postoperative vision loss (POVL), which is one of the most feared complications after spinal surgery. One of the main mechanisms of IOP elevation in the prone position is the impediment of venous return in the head and neck region due to gravity, leading to an increase in episcleral venous pressure. Additionally, direct mechanical pressure on the face and globe can also increase IOP. Anesthesia management can also play a role in IOP dynamics by affecting intrathoracic pressure and venous return. This complex interaction necessitates careful monitoring of eye health in anesthetized patients in the prone position. Non-contact tonometers offer a non-invasive, rapid, and reliable method for IOP measurement. They are particularly advantageous for repeated measurements in anesthetized patients. This clinical study aims to evaluate changes in IOP using a non-contact tonometer in patients undergoing laminectomy in the prone position and to identify anesthesia- and patient-related factors influencing these changes. The data obtained will contribute to the development of anesthesia and positioning strategies aimed at reducing the risk of ocular complications.

Improvement of Lung and Thoracic Compliance in ARDS Patients in Prone Position by Using Inflatable Air Bag

ARDS is frequent in ICU and may lead to many complications and to death. Prone position is widely used in ADRS patients and demonstrated to decrease mortality. Regarding the chest wall compliance data are missing but the theorical response is that this compliance is decreased in a prone position mainly due to anterior chest and abdomen compression in this position which are more compliant that dorsal part of the body. As well prone position could be associated with complications as pressure ulcers. Because prone position is associated with complications, air bag were developped to decrease pressure on the chest and abdomen and to decrease pressure ulcers. Then, trying to improve chest compliance in prone position and reducing the risk of pressures ulcers could be a challenge with this system in comparison with standard care.

Supporting Infant Development Through Tummy Time, Positioning, and Limiting Baby Gear

The goal of this clinical trial is to examine the impact of an educational intervention on infant motor skill development. The main question it aims to answer is: Question 1) Does exposure to an educational intervention on infant development positively impact infant motor skill development? Researchers will compare the intervention group to the treatment as usual group see if there are differences in infant motor skill development. The purpose of the proposed study is to determine if tummy time, play positions, screen time, and use of baby gear impacts early motor skill development in children. This is a Pilot study. A Pilot study is a small study that is carried out to collect information that will help in the planning of a larger study with the same topic.

By Assessing the Continuous Respiratory Physiological Changes Through Prone Position, Determine the Optimal Duration for Prone Position

The prone position leads to a more homogeneous distribution of ventilation by inflation of collapsed alveoli and reduction in alveolar hyperinflation. By employing EIT, the study can obtain a thorough comprehension of the ongoing alterations in regional ventilation before and after adopting the prone position. It is also anticipated that there is an impact on inflammation biomarkers before and after the prone position. This assessment aids in determining the ideal duration for prone position therapy, encompassing the necessary hours and days in the prone position.

Robot-assisted Laparoscopic Partial Nephrectomy Via the Extraperitoneal Approach in the Prone Position Versus the Lateral Position

The goal of this clinical trial is to investigate whether robot-assisted laparoscopic partial nephrectomy by extraperitoneal approach in the prone position had any advantages over the traditional lateral position. The main questions it aims to answer are: Is prone surgery safe and feasible, and what are the advantages over the traditional lateral position? Does surgery in the prone position have an impact on the patients\' prognosis? Researchers will compare prone position to lateral position to see if robot-assisted laparoscopic partial nephrectomy by extraperitoneal approach in the prone position has any advantages over the traditional lateral position and whether it has any significant effect on the prognosis of the patients. Participants will be randomly allocated 1:1 to two groups: prone position group and lateral position group. The enrolled patients will be underwent robotic-assisted laparoscopic partial nephrectomy via extraperitoneal approach according to the corresponding positions of their groups. Demographic indicators and perioperative-related indicators will be counted and recorded. CT or MRI and related biochemical examinations will be reviewed at 1 month, 3 months, 6 months and 1 year after surgery, and every 1 year thereafter. The similarities and differences of the indicators in different positions will be analysed, and subgroup analyses will be performed according to the corresponding results.

Effect of PP in Patients With Ultra-low VT

Acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome with similar clinicopathological feathers caused by different etiologies. Respiratory supportive strategies is the main ARDS management, and the guidelines recommend low tidal volume to improve clinical outcomes. To be note, overdistension can still occur even if using a tidal volume as low as 6 ml/kg, given the heterogeneous nature of the syndrome. Therefore, adjusting tidal volume level to less than 6ml/kg may reduce ventilator-induced lung injury (VILI) and thus improve outcomes, especially in patients with severe lung injury. Prone position is also an important management in severe ARDS. Prone position can improve ventilation-perfusion (V/Q) matching and reduce the risk of VILI by recruiting dorsal collapsed alveoli. Meanwhile, prone position has also been shown to improve hemodynamics. Recent studies have showed that prone position did not reduce duration of venovenous extracorporeal membrane oxygenation (VV-ECMO) and 90-day mortality in patients with ARDS who receive VV-ECMO with ultra-low tidal volume ventilation. Therefore, the effect of PP on ventilation and lung blood flow in ARDS patients treated with VV-ECMO wiht ultra-low tidal volume ventilation remains unclear.

A Questionnaire Survey on Cognition of Enteral Nutrition Implementation in Patients Requiring Mechanical Ventilation in Prone Position

Prone ventilation is an important treatment for respiratory failure with intractable hypoxia, and the Corona Virus Disease 2019(COVID-19 ) outbreak has further elevated the status of prone ventilation. Early enteral nutrition (EN) is also recognised as an important measure to improve the prognosis of critically ill patients. However, the administration of enteral nutrition during prone position is still quite controversial. In this paper, we analysed the tolerance and safety of enteral nutrition in the prone position by reviewing studies before and after the COVID-19 outbreak. Key strategies to improve the tolerability of enteral nutrition in the prone position are also summarised and discussed.