Concentration of lignocaine used
**Concentration of Lignocaine Used**
**Core Concept**
The concentration of lignocaine (lidocaine) used in clinical practice is crucial for its effectiveness and safety. Lignocaine is a local anesthetic that works by blocking sodium channels in nerve fibers, preventing depolarization and thereby numbing the area. The concentration of lignocaine used depends on the specific application, such as surface anesthesia, infiltration, or epidural anesthesia.
**Why the Correct Answer is Right**
For surface anesthesia, a low concentration of lignocaine (2-4%) is usually sufficient to numb the mucous membranes. In contrast, infiltration anesthesia requires a higher concentration (5-7%) to achieve adequate analgesia. Epidural anesthesia typically uses a concentration of 1-2% lignocaine, often in combination with other agents. The choice of concentration is critical to avoid toxicity, particularly central nervous system (CNS) and cardiovascular effects.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the context in which lignocaine is being used. The concentration of lignocaine can vary significantly depending on the application.
**Option B:** This option is incorrect because it suggests a concentration that is too high for surface anesthesia, increasing the risk of toxicity.
**Option C:** This option is incorrect because it is too low for infiltration anesthesia, potentially leading to inadequate analgesia.
**Clinical Pearl / High-Yield Fact**
When using lignocaine, it's essential to consider the concentration and dose in relation to the patient's weight, medical history, and the specific application. Always refer to the most up-to-date guidelines and consult with a colleague if unsure.
**Correct Answer: D. 1-2%**