Atelectasis, Postoperative Pulmonary Complications (PPCs)
Conditions
Keywords
Laparoscopic gastrectomy, Lung-protective ventilation, Positive end-expiratory pressure
Brief summary
The goal of this clinical trial is to learn if lung-protective ventilation can improve perioperative oxygenation and reduce postoperative pulmonary complications in patients undergoing elective laparoscopic gastrectomy. The main questions it aims to answer are: * Does lung-protective ventilation improve intraoperative and postoperative gas exchange compared to conventional ventilation? * What are the effects of this ventilation strategy on pulmonary mechanics, hemodynamic parameters, and the incidence of postoperative pulmonary complications? Researchers will compare lung-protective ventilation to conventional ventilation to see if the protective strategy safely mitigates atelectasis and improves oxygenation during surgery. Participants will: * Receive either conventional ventilation or lung-protective ventilation (using lower tidal volumes with appropriate PEEP and recruitment maneuvers) while under general anesthesia for their surgery. * Have their gas exchange, pulmonary mechanics, and hemodynamic parameters continuously monitored during and after the operation. * Be assessed for any postoperative pulmonary complications following the surgery.
Interventions
PROCEDUREConventional Ventilation
Patients in this group will receive conventional intraoperative mechanical ventilation during surgery. The ventilator settings include a tidal volume (VT) of 8 ml/kg based on predicted body weight (PBW) and a positive end-expiratory pressure (PEEP) of 5 cmH2O.
PROCEDURELung-Protective Ventilation
Patients assigned to the lung-protective ventilation arm will receive a standardized intraoperative strategy using Volume-Controlled Ventilation (VCV) with a tidal volume of 6 ml/kg based on predicted body weight, a respiratory rate of 12 breaths per minute, an I:E ratio of 1:2, and an inspiratory pause greater than 0.2 seconds to minimize resistance for compliance calculations. Following an initial alveolar recruitment maneuver, a decremental PEEP titration will be performed by starting at 14 cmH2O and decreasing by 2 cmH2O every 4 minutes down to a minimum of 6 cmH2O to identify and maintain the optimal PEEP level, which is defined as the point of highest dynamic lung compliance. Furthermore, automated alveolar recruitment maneuvers applying a sustained pressure of 40 cmH2O for 15 seconds will be systematically executed immediately after endotracheal intubation, repeated every 30 minutes throughout the surgical procedure, and performed a final time immediately before extubation.
Sponsors
University Medical Center Ho Chi Minh City (UMC)
Hanoi Medical University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Intervention model description
Prospective, randomized, controlled, single-blind, parallel-group clinical trial
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Age 18-70 years scheduled for elective laparoscopic gastrectomy with ananticipated operative time \> 3 hours. * American Society of Anesthesiologists (ASA) physical status I-III. * Body mass index (BMI) \< 30 kg/m².
Exclusion criteria
* Gestational diabetes mellitus or pre-existing (chronic) diabetes mellitus * Gestational hypertension or chronic hypertension * Body mass index (BMI) ≥ 35 kg/m² * Known allergy to dexamethasone * Current long-term corticosteroid therapy * Diagnosis of postpartum hemorrhage
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Intraoperative and Postoperative Gas Exchange (PaO2/FiO2 Ratio) | Assessed at 4 specific time points: T1: Baseline (before induction of anesthesia). T2: 1 hour after the start of CO2 pneumoperitoneum. T3: 30 minutes after tracheal extubation. T4: Postoperative day 1 (approximately 24 hours after surgery). | The ratio of arterial oxygen partial pressure (PaO2) to fractional inspired oxygen (FiO2). This index is used to evaluate the efficiency of pulmonary gas exchange and oxygenation status. PaO2 values are obtained from arterial blood gas (ABG) analysis. A higher ratio indicates better oxygenation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Peak Inspiratory Pressure (Ppeak) | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | The study will evaluate pulmonary mechanics by measuring the peak inspiratory pressure (Ppeak). |
| Driving Pressure (Pdriving) | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | The study will evaluate pulmonary mechanics by measuring the driving pressure (Pdriving). |
| Plateau Pressure (Pplat) | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | The study will evaluate pulmonary mechanics by measuring the plateau pressure (Pplat). |
| Dynamic Lung Compliance (Cdyn) | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | The study will evaluate pulmonary mechanics by measuring the dynamic lung compliance (Cdyn). |
| Static Lung Compliance (Cstat) | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | The study will evaluate pulmonary mechanics by measuring the static lung compliance (Cstat). |
| Intraoperative Mean Arterial Pressure | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | Hemodynamic stability will be evaluated by measuring the mean arterial pressure (MAP). |
| Intraoperative Heart Rate | Assessed intraoperatively (recorded at post-intubation, 30 minutes after CO2 insufflation, every hour during CO2 insufflation, 10 minutes after CO2 exsufflation, and before extubation). | Hemodynamic stability will be evaluated by measuring the heart rate. |
| Incidence of Intraoperative Hypotension and Vasopressor Use | During the anesthesia and surgical procedure. | The study will record the number of participants experiencing intraoperative hypotension, defined as mean arterial pressure \< 65 mmHg or systolic blood pressure \< 90 mmHg, and the number of participants requiring vasopressors (ephedrine or phenylephrine). |
| Incidence of Postoperative Pulmonary Complications | Atelectasis and pneumothorax assessed on postoperative day 1; pneumonia and ARDS assessed within 7 days after surgery. | The study will record the number of participants experiencing specific postoperative pulmonary complications, including atelectasis, pneumothorax, pneumonia, and acute respiratory distress syndrome (ARDS). |
| Incidence of Intensive Care Unit (ICU) Admission | Up to 7 days postoperatively | The study will record the number of participants requiring transfer to the intensive care unit from the post-anesthesia care unit due to respiratory complications. |
| Length of Hospital Stay | From the date of surgery until hospital discharge, assessed up to 30 days. | The study will evaluate the length of hospital stay, calculated from the date of surgery to the date of hospital discharge. |
Countries
Vietnam
Outcome results
None listed