The goal of this observational study is to learn how the length of pneumoperitoneum during laparoscopic inguinal hernia surgery may affect changes in blood bicarbonate levels. Pneumoperitoneum is the use of carbon dioxide gas to create space inside the abdomen during laparoscopic surgery.

The main question this study aims to answer is whether a longer pneumoperitoneum time is associated with changes in blood bicarbonate levels after surgery.

Participants are adults undergoing laparoscopic inguinal hernia repair as part of their routine medical care. Researchers will measure blood gas values, including bicarbonate levels, before surgery and again two hours after surgery. The change in bicarbonate levels will be compared with the duration of pneumoperitoneum during the operation.

The results of this study may help improve the understanding of metabolic changes that occur during laparoscopic surgery.

Carbon dioxide pneumoperitoneum is routinely used during laparoscopic surgery to provide adequate visualization and working space. However, absorption of carbon dioxide and increased intra-abdominal pressure may influence acid-base balance during the perioperative period. These physiological changes may be reflected in blood gas parameters such as pH, partial pressure of carbon dioxide (pCO2), and serum bicarbonate levels.

This prospective observational study aims to evaluate the relationship between pneumoperitoneum duration and perioperative changes in serum bicarbonate levels in patients undergoing laparoscopic inguinal hernia repair using the transabdominal preperitoneal (TAPP) technique.

Adult patients undergoing elective laparoscopic inguinal hernia repair will be included in the study. Blood gas measurements will be obtained before surgery and at the second postoperative hour. Serum bicarbonate levels will be recorded, and the difference between preoperative and postoperative measurements (ΔHCO3-) will be calculated.

The primary outcome of the study is the change in serum bicarbonate levels between the preoperative and postoperative second-hour measurements. Secondary outcomes include postoperative pain scores, postoperative acid-base parameters such as pH and pCO2, and early postoperative complications within the first 24 hours.

Pneumoperitoneum duration will be recorded intraoperatively and analyzed for its association with perioperative metabolic changes. The findings of this study may contribute to a better understanding of metabolic alterations occurring during laparoscopic surgery and their potential clinical implications.

Inclusion Criteria:

• Age ≥18 years
• Patients undergoing laparoscopic inguinal hernia repair using the TAPP technique
• Ability to provide informed consent

Exclusion Criteria:

• Pregnancy
• Severe cardiovascular disease
• Renal insufficiency
• Patients requiring additional intra-abdominal surgical procedures
• Strangulated inguinal hernia requiring bowel resection

Adult patients undergoing laparoscopic inguinal hernia repair (TAPP) at Haseki Training and Research Hospital will be included. Perioperative pneumoperitoneum duration and serum bicarbonate changes will be analyzed using blood gas measurements obtained preoperatively and at the second postoperative hour.

Individual participant data will not be shared due to institutional data protection policies and patient confidentiality requirements. Only aggregated and anonymized data will be reported in scientific publications.