Postoperative gastric distension is a common gastrointestinal complication after cardiac surgery and may delay recovery, prolong intensive care unit (ICU) stay, and reduce patient comfort. Anti-bloating patches are widely used in clinical practice to promote gastrointestinal function recovery; however, high-quality evidence regarding their effectiveness in cardiac surgical patients remains limited.

This randomized controlled trial aims to evaluate the efficacy and safety of an anti-bloating patch in reducing postoperative gastric distension after cardiac surgery. Adult patients undergoing cardiac surgery will be randomly assigned to receive either standard perioperative care alone or standard perioperative care plus anti-bloating patch therapy. Gastric bubble area will be quantitatively measured using chest radiographs and image analysis software.

The primary outcome is the change in gastric bubble area on postoperative day 1 compared with baseline. Secondary outcomes include gastric bubble area on postoperative day 1, percentage change in gastric bubble area, abdominal distension score, time to first flatus, time to first bowel movement, gastric drainage volume, time to oral feeding, ICU length of stay, postoperative hospital length of stay, and patch-related adverse events.

The results of this study may provide evidence for the use of anti-bloating patches as an adjunctive intervention to enhance postoperative gastrointestinal recovery in patients undergoing cardiac surgery.

Background Postoperative gastrointestinal dysfunction is frequently observed after cardiac surgery because of surgical stress, cardiopulmonary bypass, anesthesia, opioid administration, and prolonged bed rest. Gastric distension may contribute to patient discomfort, delayed gastrointestinal recovery, prolonged hospitalization, and increased healthcare utilization. Although anti-bloating patches are commonly used as a complementary intervention in perioperative care, evidence regarding their efficacy in cardiac surgery patients remains insufficient.

Objective To evaluate the clinical efficacy and safety of anti-bloating patch therapy for postoperative gastric distension in patients undergoing cardiac surgery and to establish an objective imaging-based method for quantitative assessment of gastric bubble area.

Methods This is a prospective, randomized, controlled, single-center clinical trial. A total of 150 adult patients undergoing elective cardiac surgery will be enrolled and randomly assigned in a 1:1 ratio to either an anti-bloating patch group or a control group.

Participants in the control group will receive standard perioperative management. Participants in the intervention group will receive anti-bloating patch therapy in addition to standard perioperative management.

Chest radiographs obtained on the day of surgery and on postoperative day 1 will be analyzed using ImageJ software. Gastric bubble area will be independently measured by trained investigators according to a predefined protocol

Inclusion Criteria:

• Age ≥18 years
• Undergoing elective cardiac surgery
• Postoperative chest radiographs available for gastric bubble area assessment
• Able to provide written informed consent or have consent provided by a legally authorized representative
• Expected postoperative intensive care unit admission

Exclusion Criteria:

• Previous major gastrointestinal surgery affecting gastric anatomy or motility
• Known gastrointestinal obstruction, perforation, or severe gastrointestinal disease
• Severe hepatic or renal dysfunction judged unsuitable by the investigators
• Known allergy or hypersensitivity to components of the anti-bloating patch
• Participation in another interventional clinical trial within the previous 30 days
• Pregnancy or lactation
• Inability to complete study assessments or follow study procedures

De-identified individual participant data underlying the published results may be made available upon reasonable request to the corresponding investigator after publication of the primary study results, subject to institutional approval and applicable data protection regulations.

De-identified individual participant data and supporting documents will be available beginning 6 months after publication of the primary study results and ending 5 years after publication.

Access to de-identified individual participant data, study protocol, statistical analysis plan, and informed consent form will be provided to qualified researchers whose proposed use of the data has been approved by the principal investigator and the sponsoring institution. Requests should include a methodologically sound research proposal. Data will be shared for the purpose of achieving the aims outlined in the approved proposal and in accordance with applicable ethical and data protection requirements.

This is an open-label study. Participants and investigators are aware of group assignments. Outcome assessment of gastric bubble area will be performed using standardized imaging analysis procedures.