Abdominal Surgery, Obese Patients
Conditions
Keywords
Open lung approach, conventional ventilation
Brief summary
the purpose of this study is to compare open lung approach versus conventional protective ventilation in obese patients undergoing open abdominal surgery
Detailed description
after being informed about the study and potential risks. All patients giving written consent will be randomized by double blind manner into 2 groups each one containing 24 patients Group SPV: will be ventilated using volume controlled ventilation (7ml/kg tidal volume) with addition of 5 cm H₂O fixed PEEP till the end of the surgery . Group OLA: The patients will undergo ARM followed by personalized PEEP.
Interventions
OTHERARM
The ARM is performed by setting the peak inspiratory pressure to 45 cmH₂O then changing the mode of ventilation to pressure controlled ventilation (PCV) with the inspiratory pressure set to give a tidal volume equal to that given during VCV, I:E ratio of 1:1 and a PEEP of 5 cmH₂O. The PEEP level is then increased in 5 cmH₂O steps every minute till it reaches 20 cmH₂O and inspiratory pressure is increased to get an airway opening pressure (inspiratory pressure + PEEP) of 40 cmH₂O which is maintained for one minute after which the ventilation returned to the original setting except for the PEEP level which is kept at 20 cmH₂O. The titration of individualized PEEP is done by decremental reduction of the 20 cmH₂O PEEP level in 2 cmH₂O steps every 2 minutes and measuring static compliance of the respiratory system (CRS) at each step.
OTHERspontanous ventilation
volume controlled ventilation (7ml/kg tidal volume) with addition of 5 cm H₂O fixed PEEP till the end of the surgery .
Sponsors
Zagazig University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
DOUBLE (Subject, Caregiver)
Masking description
Participant, Care Provider
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Patient aged between 18 - 65 years * BMI between 30-40 kg/m² * ASA I and II,open elective abdominal surgery which is expected to last for more than 2 hours under general anesthesia and planned to be extubated at the end of surgery
Exclusion criteria
* Emergency surgery, pregnancy, chronic obstructive pulmonary disease (FEV1 \< 80% of the predicted value) * active asthma, acute respiratory distress syndrome * history of pneumothorax, lung cyst, Difficult airway, obstructive sleep apnea,ischemic heart disease, heart failure * significant arrhythmias and intracranial hypertension. Exposure to radiotherapy and chemotherapy within 2 months before surgery. Advanced Cardiovascular ,liver, renal diseases ischemic heart disease, heart failure, significant arrhythmias and intracranial hypertension
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| post-operative pulmonary complications | one week postoperative | Pulmonary function tests will be done before surgery as a baseline then repeated after the surgery when the patient is fully awake using bedside spirometer in the sitting position. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| heart rate | Baseline (before surgery) and intraoperative | hemodynamic changes |
| airway pressure | intraoperative | During mechanical ventilation airway pressures will be continuously monitored. |
| pulmonary complications. | one week postoperative | 1\. Postoperative pulmonary complications which are defined as having one or more of the following: 1.Pneumonia 2. Respiratory failure requiring mechanical ventilation (Postoperative PaO2 \< 60 mm Hg on room air, a PaO2:FiO2 ratio \< 300 mm Hg) or peripheral oxygen saturation (SpO₂) \<90% and requiring oxygen therapy ). 3. Atelectasis requiring bronchoscopic intervention 4. Pulmonary edema ( postoperative acute lung injury or ARDS). 5. Delayed tracheal extubation ( \>24 hours postoperatively) or need for reintubation (because of respiratory distress, hypoxia, hypercarbia, or respiratory acidosis). 6. Pneumothorax 7. Bronchospasm (Newly detected refractory expiratory wheeze requiring bronchodilators |
| mean arterial blood pressure | Baseline (before surgery) and intraoperative | hemodynamic changes |
| ETCO2 | Baseline (before surgery) and intraoperative | hemodynamic changes |
| tidal volume | intraoperative | During mechanical ventilation tidal volume will be continuously monitored. |
| SpO2 | Baseline (before surgery) and intraoperative | hemodynamic changes |
| length of hospital stay, | postoperative up to one month | the length of hospital stay, and 30 days mortality. |
Countries
Egypt
Outcome results
None listed