Prevention of Perioperative Pulmonary Complications by Lung Recruitment During Laparoscopic Surgery

The multi-center RCT will enroll 80 patients who have laparoscopic surgery in Trendelenburg head-down position. Informed consent will be obtained for study subjects who meet the selection criteria, and the subjects will be enrolled in Electronic Data Capture and randomized into two groups. Patients will be admitted to the operating room for induction of anesthesia and tracheal intubation. In the control group, mechanical ventilation will be performed according to the initial settings and protocols. In the intervention group, after intubation, the ventilator will be initially set up, and the first pulmonary recruitment will be performed immediately after the start of the laparoscopy, followed by recruitment every 30 minutes until the end of the laparoscopy.

• lung recruitment (Procedure): Automatic lung recruitment using the anesthetic machines (with PEEP 15 cmH2O for 30 seconds) will be performed every 30 minutes during laparoscopy.
• Standard ventilatory management (Procedure): After tracheal intubation, standard ventilatory management (metered ventilation) should be performed with the following initial settings, and rescue should be performed when hypoxemia occurs, if necessary. \[initial setting\] PEEP 4cmH2O, FIO2 0.3 Ventilation rate: 6-8 ml/kg predicted body weight (PBW)

Primary outcomes

• Incidence of hypoxia [During laparoscopy procedure]: SpO2 less than 95% or more than 2% decrease from baseline
• Time to onset of hypoxia [During laparoscopy procedure]: Duration from the start of laparoscopic surgery to the onset of hypoxia

Secondary outcomes

• Rate of decrease in SpO2 [During laparoscopy procedure]: Difference between baseline SpO2 and minimum SpO2 during laparoscopic surgery
• Ventilator setting at the end of surgery [During surgery]: Ventilator settings such as FIO2, PEEP, and plateau pressure
• compliance rate of lung recruitment [During laparoscopy procedure]: compliance rate of lung recruitment in the intevention group
• Safety endpoint: Circulatory agonist use [During surgery]: Circulatory agonist use
• Safety endpoint: total fluid infusion [During surgery]: total fluid infusion
• Safety endpoint: incidence of complications [During surgery]: incidence of complications (hypotension, arrhythmia, pneumothorax, atelectasis defined by the blinded investigator)
• Postoperative hypoxia [the day after surgery]: Presence of hypoxia the day after surgery

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Patients undergoing low head laparoscopic surgery who are expected to be laparoscopic for more than 2 hours

Exclusion Criteria:

* Lateral or supine position
* BMI > 35
* One-second rate <70%, %VC <80%, obstructive, restrictive, with bra
* Cardiovascular disease (NYHA III or higher)
* Intracranial hypertensive disease
* Emergency surgery
* Pregnancy
* Glaucoma
* Patients judged unsuitable by the anesthesiologist in charge

• Yuji Fujino, Study chair, Department of Anesthesiology and Intensive Care Medicine, Osaka University