A medical assistant is administering 1 mL of medroxyprogesterone by deep intramuscular injection to an adult patient using the ventrogluteal site. To deliver the dose safely, what is the BEST technique?
- ASpread the skin taut between two fingers, insert a 22 gauge 1 and a half inch needle at a 90 degree angle, and inject at about 1 mL per 10 seconds. Correct
- BStretch the skin flat over the site, insert a 25 gauge five-eighths inch needle at a 45 degree angle, and inject slowly.
- CPinch a fold of skin, insert a 23 gauge 1 inch needle at a 90 degree angle, and inject without aspirating.
- DUse Z-track technique, insert a 25 gauge 1 inch needle at a 90 degree angle, and inject the full dose within two seconds.
Why A is correct: For an adult ventrogluteal IM injection of a viscous suspension, taut skin and a 90 degree insertion with a 22 gauge 1 and a half inch needle reach the gluteus medius reliably, and slow delivery of about 1 mL per 10 seconds reduces pain and tissue trauma.
Why B is wrong: A 25 gauge five-eighths inch needle at 45 degrees is a subcutaneous technique and will not deposit the dose into the gluteus medius; an oily depot suspension placed in subcutaneous tissue can cause sterile abscess and erratic absorption.
Why C is wrong: Pinching tents the tissue away from muscle and is a subcutaneous landmark, not an intramuscular one; a 1 inch needle on a pinched ventrogluteal site risks delivering the depot suspension into fat rather than the gluteus medius.
Why D is wrong: While Z-track is acceptable for some IM agents, a 25 gauge 1 inch needle is generally too short to reach the gluteus medius in an average adult, and injecting 1 mL within two seconds is too rapid and increases pain and leakage risk.