Why did the "butt injection" that was popular when we were young disappear?

When it comes to injections, what comes to your mind is "injection in the buttocks" or "injection in the arm"? For older friends, it may be an injection in the buttocks. But now, it seems that buttocks injections are rarely given. Recently, the question of "Why have buttocks injections disappeared?" has attracted widespread attention and discussion on Weibo. Have the buttocks injections we used to get when we were young really disappeared? This starts with what buttocks injections are.

What is a butt shot?

What we call buttock injection is actually a form of intramuscular injection, which means injecting the drug into muscle tissue. In addition to intramuscular injection, there are also common intravenous injection, subcutaneous injection, and intradermal injection, which are suitable for different types of scenarios.

1

Intradermal injection

This is the injection method we usually use when doing a "skin test". The doctor will place the needle close to the surface of the skin and inject the medicine. This is because the injection point is very close to the surface of the body, and if the body reacts, it is easier to observe.

It looks painful to do a "skin test", Image source: wikimedia

2

Subcutaneous injection

The most common method is insulin injection. Large molecular proteins such as insulin are not suitable for oral administration and need to be administered by injection. Subcutaneous injection is simpler than intravenous injection and intramuscular injection, and can be performed without professional medical staff. For insulin that needs long-term injection, this injection method is very suitable.

Subcutaneous injection area, Image source: wikimedia

3

Intravenous injection

Intravenous injection, as the name implies, is to inject the drug directly into the vein. What we call hanging water and dripping belong to intravenous injection. The advantage of this injection method is that the drug is directly injected into the blood, the drug is not easily metabolized by organs such as the liver, and it can be delivered to the whole body as quickly as possible. When the drug needs to take effect quickly, the doctor will choose this method.

Intravenous injection, Image source: wikimedia

4

Intramuscular injection

Like intravenous injection, intramuscular injection can also prevent drugs from being metabolized by the liver. Compared with intravenous injection, intramuscular injection of drugs will take longer to take effect. This injection method is often used when injecting many types of vaccines and drugs that may cause greater irritation to blood vessels. The muscles in the buttocks are very "thick", so they naturally become one of the "excellent candidate areas" for intramuscular injection. In addition, the outer thigh (rectus femoris) and the deltoid muscle on the arm are also "candidate areas" for intramuscular injection.

Intramuscular injection, Image source: wikimedia

However, many people may still have some "childhood trauma" about buttock injections. It seems that buttock injections are more painful than "arm injections". Why is this?

Why do butt shots hurt so much?

First of all, this may be related to our lower tolerance for pain when we were young and our psychological fear of injections. But in addition to this, there are indeed several objective factors that make buttock injections particularly painful.

1

Blunt needle

For people born in the 1950s and 1960s, pain may come from repeatedly using "blunt needles". When medical conditions were still developed, many hospitals and clinics did not use disposable needles, but sterilized and reused needles. For example, the "needle sterilizer" below is used to sterilize needles.

Needle sterilizer, source: Product screenshot

Although it is reasonable to grind the needle tip flat after repeated use for a period of time, it is inevitable that there will be some "small burrs" on the needle after repeated use. You don't need to experience it yourself, just imagine how painful it would be if such a needle pierced into the flesh.

2

"Deeply pierced"

After the improvement of medical conditions, although the problem of "blunt needles" has been solved, in order to avoid the thick fat layer on the buttocks, buttocks needles are often inserted very deep, often needing to penetrate 2 to 3 centimeters into the flesh. The deep wound caused by the needle will also increase the pain.

3

"Suction"

In the past, when giving buttocks injections, medical staff may follow an operation to aspirate before injection to ensure that the needle does not pierce the blood vessels (otherwise it becomes an intravenous injection). A 2015 review pointed out that the action of aspiration can cause more pain than direct injection. Currently, the US Centers for Disease Control and Prevention, the Canadian Public Health Agency and other institutions also believe that there are no large blood vessels in the area of ​​​​muscle injection, and there is no need to aspirate during injection. But in any case, aspiration may also be one of the culprits for why we felt that buttocks injections were "painful" when we were young.

Are butt shots gone?

So why are buttock injections becoming less and less common now? Have buttock injections really disappeared? Let me first give you the answer: In fact, buttock injections have not disappeared, but the scenarios where they are needed have become fewer. The most important reason is that with the development of modern medicines, there are more drugs that can be taken orally, such as various penicillin derivatives, than before. Since you can solve the problem with medicine, who would be willing to get a shot? Moreover, for adults, most vaccines that do not have a particularly large dosage can also be completed through arm needles (deltoid muscle injections), so there is no need to take off your pants for injections. In addition, a 2006 study also showed that the effect of buttock injections may not be as good as imagined. As the problem of obesity becomes increasingly serious, the thickness of people's subcutaneous fat layer increases, which brings trouble to buttock injections. The study counted the effects of buttock injections on 50 patients and found that only 16 people had real intramuscular injections, and the other 34 people actually had subcutaneous injections (injected into the fat layer), which may make vaccines that require intramuscular injections ineffective. In addition, irregular buttock injections may also cause sciatic nerve damage. Combined with these reasons, buttock injections are becoming less and less common. But for some intramuscular injection drugs with large dosages, you may still have to rely on buttock injections to make them effective.

References

[1]Usach,I.,Martinez,R.,Festini,T.,&Peris,JE(2019).SubcutaneousInjectionofDrugs:LiteratureReviewofFactorsInfluen cingPainSensationattheInjectionSite.Advancesintherapy,36(11),2986–2996.https://doi.org/10.1007/s12325-019-01101-6

[2]WrightJC,BurgessDJ(29January2012).Longactinginjectionsandimplants.Springer.p.114.ISBN978-1-4614-0554-2.

[3]SissonH.Aspiratingduringtheintramuscularinjectionprocedure:asystematicliteraturereview.JClinNurs.2015Sep;24(17-18):2368-75.doi:10.1111/jocn.12824.Epub2015Apr14.PMID:25871949.

[4]ChanVO,ColvilleJ,PersaudT,etal.Intramuscular injections into the buttocks:aretheytrulyintramuscular?[J].Europeanjournalofradiology,2006,58(3):480-484.

[5]ZuckermanJ.N.(2000).Theimportanceofinjectingvaccinesintomuscle.Differentpatientsneeddifferentneedlesizes.BMJ(Clinicalresearched.), 321(7271),1237–1238.https://doi.org/10.1136/bmj.321.7271.1237

Author: Science Scraps Popular Science Creation Team

Reviewer: Tang Qin, Director and Researcher of the Science Popularization Department of the Chinese Medical Association