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.