Questions: What is the proper length of time to allow topical anesthetic to remain on the tissue at the injection site? 1 to 2 minutes 2 to 4 minutes 5 to 6 minutes Until patient reports that he is numb

The answer is the second one (2 to 4 minutes): 2 to 4 minutes.

Explanation for each option:

1. 1 to 2 minutes: This duration is generally too short for most topical anesthetics to achieve their full effect. While some initial numbing might occur, it is often not sufficient for complete anesthesia.
2. 2 to 4 minutes: This is the recommended duration for most topical anesthetics to effectively numb the tissue. It allows enough time for the anesthetic to penetrate the tissue and provide adequate pain relief.
3. 5 to 6 minutes: While this duration would also ensure numbness, it is typically longer than necessary. Most topical anesthetics reach their peak effectiveness within 2 to 4 minutes.
4. Until patient reports that he is numb: This is not a reliable method because patients' perceptions of numbness can vary. It is better to follow a standardized time frame to ensure consistent results.

Summary: The proper length of time to allow topical anesthetic to remain on the tissue at the injection site is 2 to 4 minutes. This duration ensures effective numbing while being efficient in clinical practice.