Adrenaline promotes haemostasis by local tamponade, vasospasm, and by thrombosis. It is used in 1 in 10,000 concentration and in 1 ml aliquots
Caution: Adrenaline injection can potentially produce angina by increasing myocardial work from pressor effects and by producing coronary artery vasospasm that can further diminish blood flow to a myocardium that is already hypoperfused from hypovolemia owing to acute UGIB. Other potential cardiovascular toxic effects from adrenaline injection include tachycardia, cardiac arrhythmias, and hypertension. These problems do not generally clinically manifest provided that 12 ml or less of adrenaline is used.
Injection technique:
- Needle is advanced tangentially into the submucosa
- Moderate resistance is expected when injecting into interstitial tissue. Minimal resistance suggests that the injection is too superficial. Too deep injection into the muscularis propria will meet with high resistance and will be ineffective. In such a case, needle should be withdrawn slightly.
- A submucosal bleb indicates proper depth of injection.
- Inject adrenaline circumferentially in four quadrants a few millimetres away from a bleeding site to decrease the bleeding rate and to clear the endoscopic field before central injection of the bleeding site.
- Blanching of the injected mucosa from vasospasm provides a preliminary clue that the adrenaline is working.
- Adrenaline typically stops bleeding initially, but bleeding may recur 20 min after injection if a permanent clot has not already been formed as adrenaline is absorbed and flushed into the circulation and its local effect, therefore, wears off.
- A second haemostatic technique should thus be applied to provide a more durable therapy.
