PEEP by Lung Ultrasound, PEEP With Dynamic Compliance
Conditions
Keywords
PEEP, Lung Ulrasound, Laparoscopic surgery, Pediatric patients.
Brief summary
Protective ventilation strategies and alveolar recruitment maneuvers (ARM) are employed in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) to improve oxygenation, prevent alveolar collapse, and reduce ventilation-induced lung injury. Recruitment maneuvers aim to open and maintain alveoli. While positive effects on oxygenation have been observed in adults, limited data in children make the clinical efficacy of these strategies uncertain. Careful application and the development of individualized treatment protocols are recommended.
Detailed description
Experimental studies have proven a relationship between inappropriate ventilation measures and delayed or even worsened recovery from acute pulmonary injury. Therefore, the importance of protective ventilation combined with recruitment maneuvers emerges. In clinical practice, this relationship is believed to significantly reduce morbidity, mortality, and injuries caused by mechanical ventilation. It is indicated in patients with severe hypoxemia, often due to acute lung injury caused by pneumonia or sepsis. The main contraindications are hemodynamic instability, pneumothorax, and intracranial hypertension. Experimental studies have shown that lung-protective ventilation has beneficial effects on both oxygenation and alveolar collapse. In children, lung-protective ventilation leads to significant reductions in alveolar collapse, lower oxygen requirements, improved pulmonary compliance, and decreased bronchopulmonary dysplasia. However, studies conducted on children are limited. Recent changes have been made regarding how children with acute hypoxemic respiratory failure are ventilated. Lachmann proposed the open lung concept, which involves opening the lungs and keeping them open during mechanical ventilation. ARM has been used for over two decades in mechanically ventilated patients with severe lung injury. Its most significant physiological outcome is the improvement in oxygenation in patients with lung damage. The procedure is typically followed by adjustments in PEEP levels, which play a fundamental role in maintaining the effectiveness of ARM. ARM is also used to prevent alveolar collapse during low tidal volume mechanical ventilation. However, its primary purpose is to protect the lungs from ventilator-induced injuries. PEEP has a key role in preventing atelectrauma and maintaining the maneuver's effectiveness. In clinical practice, these strategies are believed to significantly reduce morbidity and mortality. In this study, it is aimed to define the limits of diaphragm-protective ventilation based on the clinical outcomes of our patients by evaluating the effects of different PEEP levels adjusted during laparoscopic abdominal surgery in pediatric patients. Additionally, it will be seeked to assess the impact of positive end-expiratory pressure levels on diaphragm thickness. Our primary hypothesis is that, in patients where ideal PEEP is applied based on dynamic compliance measured with ultrasound (USG), diaphragm values will return closer to baseline values compared to those where recruitment maneuvers and ideal PEEP are applied. Secondly, it is aimed to investigate the effects of calculating ideal PEEP using dynamic compliance measured with USG on hospital length of stay, intraoperative hemodynamic parameters, and respiratory parameters.
Interventions
Application of Lung Ultrasound and PEEP After intubation, PEEP starts at 5 cmH2O. The first lung ultrasound (USG) is performed after 5 minutes. If the lung consolidation score is ≥2, PEEP increases by 2 cmH2O and is reassessed every 5 minutes until the score is \<2. If \<2, PEEP remains unchanged as the optimal level. This process is repeated after pneumoperitoneum, peritoneal deflation, and position changes. In Group U, PEEP is determined by USG, with a maximum of 20 cmH2O, a plateau pressure of 30 cmH2O, and a peak inspiratory pressure of 40 cmH2O.
Application of PEEP with Dynamic Compliance * After endotracheal intubation, PEEP will be applied as 5 cmH2O. * The first dynamic compliance (TV/Ppeak-PEEP) monitoring will be performed automatically by the ventilator (Mindray) 5 minutes after endotracheal intubation, and the PEEP value will be increased by 3 cmH2O. The obtained Cdyn value will be repeated after six respiratory cycles, and if there is an increase, the PEEP value will be increased by 2 cmH2O. When a decreasing trend is observed in the Cdyn value as a result of consecutive automatic measurements of 6 respiratory cycles, the PEEP value applied in the previous measurement will be determined as the most appropriate PEEP value for the participant.
Sponsors
Study design
Eligibility
Inclusion criteria
* Participants meeting the following criteria will be included in the study: * Aged 7 to 12 years * ASA classification I, II, or III * Undergoing elective laparoscopic abdominal surgery
Exclusion criteria
Participants with any of the following conditions will be excluded from the study: * Age \<7 or \>12 years * ASA classification \> III * Uncontrolled bronchial asthma * Presence of bullous lung disease * Decompensated heart failure (NYHA Stage III-IV) * History of lung surgery * Increased intracranial or intraocular pressure * Advanced hepatic or renal failure * Parental refusal to participate in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragm thickness 1 | Baseline measurement prior to anesthesia induction (within 30 minutes before surgery). | Diaphragm Thickness Measurement In the supine position, diaphragm thickness will be measured at the junction of the midaxillary line, between the 8th or 9th intercostal spaces on the right side. Using a high-frequency linear probe and ultrasound (DC-60 Diagnostic Ultrasound, Shenzhen Mindray, China), measurements will be recorded during inspiration and expiration. Once a clear diaphragm image is obtained, the skin at the probe's caudal end will be marked with indelible ink. All images will be captured with the probe in the same position. The average of inspiratory and expiratory diaphragm thickness will be used to calculate the diaphragm thickness ratio. |
| Diaphragm thickness 2 | Immediately after extubation in the operating room (within 5 minutes of extubation). | Diaphragm Thickness Measurement In the supine position, diaphragm thickness will be measured at the junction of the midaxillary line, between the 8th or 9th intercostal spaces on the right side. Using a high-frequency linear probe and ultrasound (DC-60 Diagnostic Ultrasound, Shenzhen Mindray, China), measurements will be recorded during inspiration and expiration. Once a clear diaphragm image is obtained, the skin at the probe's caudal end will be marked with indelible ink. All images will be captured with the probe in the same position. The average of inspiratory and expiratory diaphragm thickness will be used to calculate the diaphragm thickness ratio. |
| Diaphragm thickness 3 | 30 minutes after surgery completion (within the postoperative recovery period, up to 30 minutes). | Diaphragm Thickness Measurement In the supine position, diaphragm thickness will be measured at the junction of the midaxillary line, between the 8th or 9th intercostal spaces on the right side. Using a high-frequency linear probe and ultrasound (DC-60 Diagnostic Ultrasound, Shenzhen Mindray, China), measurements will be recorded during inspiration and expiration. Once a clear diaphragm image is obtained, the skin at the probe's caudal end will be marked with indelible ink. All images will be captured with the probe in the same position. The average of inspiratory and expiratory diaphragm thickness will be used to calculate the diaphragm thickness ratio. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Definition and Assessment of Postoperative Pulmonary Complications (PPCs) | From the end of surgery until 24 hours postoperatively. | Definition and Assessment of Postoperative Pulmonary Complications (PPCs) PPCs will be considered positive if at least one of the following conditions occurs within the first 24 hours postoperatively: Mild Respiratory Failure: PaO₂ \< 60 mmHg or SpO₂ \< 90% requiring ≤2 L/min O₂ therapy. Moderate Respiratory Failure: PaO₂ \< 60 mmHg or SpO₂ \< 90% requiring \>2 L/min O₂ therapy. Severe Respiratory Failure: Need for non-invasive or invasive ventilation. ARDS: Defined by the Berlin criteria. Bronchospasm: Newly detected expiratory wheezing treated with bronchodilators. Pulmonary Infection Pleural Effusion Pulmonary Atelectasis Cardiopulmonary Edema Pneumothorax |
Countries
Turkey (Türkiye)