Drug used in infiltrating anesthesia ?

Appeared in: AIIMS Rishikesh & Jodhpur NO - 2017

Explanation

Lignocaine is a common local anesthetic used for infiltration anesthesia, which involves injecting the drug directly into the tissues.
Standard concentrations for infiltration and nerve blocks range from 0.5% to 2%.
Among the given choices, 2% Lignocaine is a widely accepted and used concentration for achieving effective local anesthesia for minor surgical procedures.
Higher concentrations like 4% and 5% are not used for infiltration due to the increased risk of systemic toxicity and are formulated for other specific routes.

Option B: This is a high-concentration, hyperbaric ('heavy') solution of Lignocaine.
Option C: This concentration is intended for surface anesthesia only.
Option D: This option is incorrect because a valid and appropriate concentration (2% Lignocaine) is listed as an option.

Clinical Relevance

Nursing practice connection: Knowing Concentrations and uses of Lignocaine for local anesthesia helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses must always double-check the concentration of a local anesthetic before administration. Using the wrong concentration can lead to ineffective anesthesia or severe systemic toxicity.
A key nursing responsibility is to monitor for signs of Local Anesthetic Systemic Toxicity (LAST), which includes circumoral numbness, metallic taste, tinnitus, dizziness, and in severe cases, seizures and cardiac arrest.
What if? If the procedure was to anesthetize the throat before an endoscopy, the correct choice would be 4% Lignocaine spray for topical application, not an injectable form for infiltration.

How to Approach the Question

First, identify the key terms in the question: 'infiltrating anesthesia' and 'drug used'.
Recall that infiltration anesthesia involves injecting a local anesthetic directly into the tissues.
Consider the common local anesthetic, Lignocaine, and its various available concentrations.
Differentiate the uses based on concentration: lower concentrations (0.5-2%) are for injection (infiltration/nerve block), while higher concentrations (4-5%) are for topical or specialized routes (spinal).
Evaluate the given options against this knowledge. 2% fits the criteria for infiltration.
Eliminate 4% (topical) and 5% (spinal/topical), confirming that 2% is the most appropriate answer.

Concept Tested & Keywords

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E6 Pharmacology Nurses Shanbhag 3e p. 148-150

E6 Pharmacology KD Tripathi Essentials 9e Part 2 p. 42-44

Practise the full AIIMS Rishikesh & Jodhpur NO - 2017

Attempt every question from this paper in a timed mock, then review the full solution for each one.