What can happen if anesthesia leaks into tissue from iv infiltration?

Some drugs used in anesthesia can irritate local tissues but most drugs that infiltrate will just be absorbed at a slower rate than if injected into a vein and since the amount that would infiltrate is much lower than what goes into the vein the overall effect is usually negligible. An infiltrated IV is very resistant to flow and is thus obvious to the anesthesiologist and something they watch for