Postoperative Diaphragm Function in Pediatric Laparoscopic Abdominal Surgery Using Compliance and PEEP Guided by Lung Ultrasound

Konya City Hospital

Status: Completed

Conditions: PEEP by Lung Ultrasound; PEEP With Dynamic Compliance

Treatments: Procedure: Lung Ultrasound and PEEP Application; Procedure: Application of PEEP with Dynamic Compliance

Study type: Interventional

Funder types: Other

Identifiers

NCT07126067

Study Pedpeep

Details and patient eligibility

About

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.

Full 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.

Enrollment: 45 patients

Sex: All

Ages: 7 to 12 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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45 participants in 3 patient groups

Patients who underwent individualized PEEP with lung USG

Active Comparator group

Description:

In participants from Group U, PEEP will initially be set at 5 cmH2O and adjusted based on lung ultrasound (USG) findings. If the lung consolidation score is ≥ 2, the PEEP level will be incrementally increased by 2 cmH2O, with USG reassessments every 5 minutes, until a score \< 2 is achieved. This process will be repeated after pneumoperitoneum, peritoneal deflation, and positional changes during surgery to establish an individualized PEEP level. The maximum PEEP value is limited to 20 cmH2O, with a plateau pressure (Pplat) cap of 30 cmH2O and a peak inspiratory pressure (PIP) limit of 40 cmH2O.

Treatment:

Procedure: Lung Ultrasound and PEEP Application

Application of PEEP with Dynamic Compliance

Active Comparator group

Description:

PEEP starts at 5 cmH2O after endotracheal intubation. The ventilator (Mindray) will automatically monitor dynamic compliance (TV/Ppeak-PEEP) 5 minutes after endotracheal insertion. PEEP will rise 3 cmH2O. The Cdyn value will be tested again after six breathing cycles, and if it increases, PEEP will be increased by 2 cmH2O. If Cdyn readings decrease during six consecutive automatic measurements, the participant's optimal PEEP level will be the prior measurement's PEEP. To calculate Cdyn-based PEEP, the same technique will be repeated following pneumoperitoneum, peritoneal deflation, and positional changes during operation. For dynamic compliance-based PEEP participants (Group D), the maximum PEEP value will be 20 cmH2O, the plateau pressure (Pplat) limit 30 cmH2O, and the peak inspiratory pressure (PIP) limit 40 cmH2O.

Treatment:

Procedure: Application of PEEP with Dynamic Compliance

Control Group

No Intervention group

Description:

Control group participants will receive conventional mechanical ventilation without PEEP modification interventions. PEEP shall stay at 5 cmH2O during surgery unless clinically indicated to change (e.g., substantial hypoxaemia or haemodynamic instability). These subjects will not undergo Cdyn or LUS measures. Instead, institutional protocols will guide intraoperative monitoring and treatment. Depending on clinical measures like oxygen saturation (SpO2), end-tidal carbon dioxide (EtCO2), and arterial blood gas (ABG), the anaesthesiologist may adjust ventilator settings. The control group serves as a baseline for comparison with the intervention groups (LUS or Cdyn-based PEEP adjustments) to determine if individualised PEEP techniques improve clinical results.