The Use of Propranolol in the Perioperative Period of Resectable Gastrointestinal Tumors

Inclusion Criteria: 1. Surgically resectable primary gastric cancer and colorectal cancer; 2. Age greater than 18 years old and less than 65 years old; 3. Negative pregnancy test for women of childbearing age; 4. ECOG score ≤2; 5. Signed informed consent. 6. Resting blood pressure greater than 100/60mmHg, heart rate greater than 60 beats per minute. Exclusion Criteria： 1\) Pregnant or breastfeeding women, or women with pregnancy plans within six months; 2) Patients with absolute or relative contraindications to propranolol: 1. Pathological sinus node syndrome; 2. Sinus bradycardia (less than 60 beats/minute); 3. First, second or third degree AV block; 4. Resting blood pressure less than 100/60 mmHg; 5. untreated pheochromocytoma; 6. untreated thyroid disease; 7. Patients on dihydropyridine or non-dihydropyridine calcium channel blockers (e.g., diltiazem, verapamil, nifedipine, amlodipine); 8. Severe peripheral vascular disease (intermittent claudication); 9. Patients on antiarrhythmic drugs (e.g., amiodarone, sotalol, digoxin); 10. Patients with renal insufficiency (defined as creatinine clearance greater than 0.15 mmol/L); 11. Patients with hepatic insufficiency: AST or ALT or ALP \> 2.5 times the upper limit of normal (ULN), bilirubin \> 1.5 times the ULN, ALP \> 2.5 12. Patients using colistin, digoxin, rizatriptan, cimetidine, hydralazine, guanethidine, or ergotamine. 13. Patients with a history of major depressive episodes; 3) Patients who have undergone surgery for GI tumors within the previous six months; 4) Patients receiving neoadjuvant chemotherapy prior to planned gastrointestinal tumor resection; 5) patients using conventional anxiolytic drugs (e.g. benzodiazepines), alpha-adrenergic agonists (e.g. colistin); 6) Patients using selective or non-selective β-adrenergic inhibitors (e.g., propranolol, metoprolol, atenolol, sotalol) within the last three months; 7) Patients with a history of stroke; 8) Patients with moderate or severe asthma, defined as requiring hospitalization or oral steroid therapy; (9) Those who, in the opinion of the physician, have other reasons for not being included in the treatment.