The Impact of Automatic Lung Recruitment Postoperative Pulmonary Complications

The Effect of Automatic Lung Re-expansion on Postoperative Pulmonary Function in Elderly Patients Undergoing Laparoscopic Surgery Under Total Intravenous Anesthesia: A Prospective, Single-center, Randomized Controlled Trial

Study Background and Purpose As society ages, an increasing number of elderly patients undergo surgery. Following surgery, particularly abdominal procedures, patients are susceptible to lung-related issues such as atelectasis (lung collapse) and infection, collectively known as Postoperative Pulmonary Complications (PPCs). These complications are a major factor affecting the recovery of elderly patients.

One method of general anesthesia is called Total Intravenous Anesthesia (TIVA). This study aims to investigate whether using an automated lung recruitment function, a smart feature available on modern anesthesia machines, can help protect lung function and reduce complications in elderly patients undergoing laparoscopic surgery under TIVA. The goal is to identify safer and more effective methods for anesthesia care.

Study Design

This is a clinical research study. Eligible elderly patients who provide consent will be randomly assigned to one of two groups:

Study Group: The automated lung recruitment function on the anesthesia machine will be used to manage breathing during surgery.

Control Group: Current standard methods for breathing management will be used during surgery.

The primary goal is to observe and compare the blood oxygenation level 30 minutes after surgery (a key indicator of lung function) between the two groups. The investigators will also record the occurrence of any lung-related complications within the first 3 days after surgery.

What Will Participants Do?

If participants agree to participate, they will be asked to:

Sign an informed consent form.

Undergo some pre-operative assessments arranged by the research team.

Receive the corresponding breathing management method during surgery, as determined by random assignment.

Allow the research team to collect relevant medical data after surgery (e.g., blood gas analysis results, medical records). All data will be kept strictly confidential.

Participation does not involve any additional invasive procedures. All medical care and monitoring will adhere to the standard safety protocols required for the surgery, and may even be more meticulous.

Potential Benefits and Risks of the Study

Potential Benefits:

Direct Benefit: Participants will receive more precise monitoring and care for their respiratory function during and after surgery.

Societal Value: Data from their participation will contribute to developing better anesthesia strategies for future elderly patients, potentially improving their recovery outcomes.

Potential Risks and Protections:

The study intervention is integrated into standard anesthesia. The main risks are associated with routine anesthesia and surgery itself (e.g., temporary blood pressure fluctuations, low oxygen levels). These risks are possible in any similar surgical procedure.

The study will be conducted by experienced anesthesiologists with continuous, close monitoring. Comprehensive emergency plans are in place to ensure participant safety.

Participants have the right to withdraw from the study at any time, for any reason, without affecting their eligibility for any future standard medical care.

All personal information and study data will be kept strictly confidential. Data will be analyzed using coded identifiers only. Any published results will not contain information that could reveal the identity of participants.

Inclusion Criteria:

• aged≥65 years
• American Society of Anesthesiologists (ASA) grades I-III;
• Body mass index (BMI) between 18-30kg/m²
• No history of drug allergy or abnormal anesthesia;
• Patients undergoing laparoscopic gastrointestinal surgery, and operative time> 2 hours;
• Participants with a preoperative oxygen saturation not < 94%
• Participants for whom extubation is planned in the operating room.
• The assess respiratory risk in surgical patients in Catalonia (ARISCAT) score is 26-44 or > 44.

Exclusion Criteria:

• ALI or ARDS patient within 3 months; severe pulmonary dysfunction; severe COPD (FEV1 <50% of predicted value) or pulmonary hypertension;
• New York Heart Association classification: Class IV;
• Chronic renal failure(GFR<30ml min-11.73m-2);
• Severe liver disease;
• Patients with confusion and cognitive dysfunction;
• Severe coagulation disorders;
• Patients with tracheal tubes transported to the ICU;
• Other reasons;