When is infiltration contraindicated?

Infiltration anesthesia involves the injection of anesthetic directly into the tissue in the area of treatment, allowing for localized pain control. However, one of the primary contraindications for using infiltration techniques is when the area is inflamed.

Inflamed tissues have altered vascularity and may have increased acidity, which can affect the diffusion of the anesthetic. Inflammation can cause the blood vessels in the area to become more permeable, which can lead to a faster systemic absorption of the anesthetic. This not only diminishes the effectiveness of the local anesthesia—increasing the likelihood that the patient may feel pain during the procedure—but it also poses a risk of toxicity since more of the anesthetic can enter systemic circulation rapidly.

Thus, using infiltration in these cases can lead to inadequate anesthesia and potential complications, making it contraindicated in areas of inflammation. In these instances, a block anesthesia technique might be more effective as it provides a greater volume of anesthetic further from the inflamed area and may achieve a more predictable anesthetic effect.