Q: Out of the following which of the octreotide effect is most responsible for decreasing portal pressure in the variceal gastrointestinal (GI) bleed? (select one)
A) Portal venous inflow
B) Portal pressures
C) Azygos flow
D) Intravariceal pressures
Answer: C
During the management of variceal GI bleed, the effect of intravenous (IV) octreotide bolus is instant within seconds with a decrease in portal venous inflow, portal pressures, azygos flow, and intra-variceal pressures. Out of all these, the most beneficial and consistent effect comes from the decrease in collateral flow via azygos flow. Although this effect lasts temporarily but with continuous infusion after IV bolus, it is hoped that hemostasis can be achieved and maintained, although tachyphylaxis is rapid.
Octreotide also increases the mean arterial pressure. Another secondary effect of octreotide is to postprandially inhibit the release of glucagon and other hormones that have roles in mediating the increase in mesenteric blood flow. It also helps to keep portal hemodynamics maintained via somatostatin receptors activation to avoid rebound in portal pressures during recovering phase with reversal of hypovolemia. This is the reason to continue IV infusion for at least 48-72 hours after bolus to see the maximum benefit.
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References:
1. Escorsell A, Bandi JC, Andreu V, et al. Desensitization to the effects of intravenous octreotide in cirrhotic patients with portal hypertension. Gastroenterology 2001; 120:161.
2. McCormick PA, Biagini MR, Dick R, et al. Octreotide inhibits the meal-induced increases in the portal venous pressure of cirrhotic patients with portal hypertension: a double-blind, placebo-controlled study. Hepatology 1992; 16:1180.
3. Ludwig D, Schädel S, Brüning A, et al. 48-hour hemodynamic effects of octreotide on postprandial splanchnic hyperemia in patients with liver cirrhosis and portal hypertension: double-blind, placebo-controlled study. Dig Dis Sci 2000; 45:1019.
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