Newsflash: We Shouldn’t Aspirate Before (Some) IM Injections

I read this recently and said, “what?” I went to nursing school not so long ago, and they taught us that when you give IM injections you should aspirate before the injection. It was almost one of those obvious things that a nurse would never question, but someone did and studied it and now we have evidence-based research that we’re not supposed to aspirate all the time anymore.

Approximately 1 year ago, some nurses did some research on the matter and published their results in “To aspirate or not: An integrative review of the evidence.” From what I can tell, their review found more that there was no evidence in favor of aspiration, versus there being evidence against it. The authors established these points:

  • Aspiration is not indicated for subcutaneous injections of immunizations, heparin, and insulin
  • Aspiration is not indicated for IM injections of vaccines and immunizations
  • Aspiration may be indicated for IM injections of medications such as penicillin
  • Until a standard can be established, injection techniques must be individualized to the patient to prevent incorrect needle placement
  • But documentation straight from the CDC (download the PDF here) has a bit more oomph behind the “do not aspirate” idea. It states

    “There are only two routinely recommended IM sites for administration of vaccines, the vastus lateralis muscle (anterolateral thigh) and the deltoid muscle (upper arm). Injection at these sites reduces the chance of involving neural or vascular structures. The site depends on the age of the individual and the degree of muscle development. Because there are no large blood vessels in the recommended sites, aspiration before injection of vaccines (i.e., pulling back on the syringe plunger after needle insertion but before injection) is not necessary‚Ķ. Also, some safety-engineered syringes do not allow for aspiration.”

    This document also cites studies that avoiding aspiration decreases pain, something that any nurse will be happy to hear. I think we all hate that look and scream from pediatric patients and would like to learn any techniques possible to decrease their pain.

    The CDC document seems to base its recommendation against aspiration on vaccine-specific research and administration locations, and the first study also separates out vaccine versus medication administration. In summary, then, evidence-based practice currently would be to avoid aspiration for vaccine administration in the deltoid or vastus lateralis, for sure and for certain.

    For other IM injections, research is still not convincing, and I would like to see a more compelling answer. The CDC document is unclear because it confines itself to vaccine injections, yet the rationale used should logically apply to any IM injection as long as these two sites are used. If there are no large blood vessels involved for vaccines, the same should apply for Phenergan or Dilaudid or Rocephin, but I hesitate to change my practice on the basis of simply extrapolating results.

    For those of us who give non-vaccine IM injections on a regular basis, this is relevant on a daily basis. If I don’t need to be aspirating before giving already-painful Rocephin injections, I would like to know about it. More research is needed on the matter, and it needs to be publicized more.

    About Megen Duffy

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    Megen Duffy, RN, BA, BSN, CEN, is a practicing nurse, blogger, and contributing editor for the American Journal of Nursing. Megen has practiced in a variety of settings from emergency rooms to prisons.