If you hit a blood vessel during an intramuscular (IM) injection, you'll usually see blood in the syringe, which means the medication might enter the bloodstream, changing absorption and potentially causing issues like vascular occlusion or, rarely, severe bleeding (hemorrhage). The key is to stop, withdraw the needle (without pushing plunger), and restart the injection in a new spot, applying pressure if needed, to prevent adverse effects from the drug entering the circulation or causing damage.
Red flags can include: Persistent numbness, tingling, or weakness in an arm or leg. Sharp, radiating pain that doesn't improve. Increasing redness, warmth, swelling, drainage, or fever.
Intramuscular (IM) injections are invasive procedures; bleeding and bruising may occur at the injection site. Although there is no definitive guidance, most IM injections are considered minimal to low-risk procedures.
Injections can also be administered in the wrong site. The most common error is steroid injections (for example, Kenalog) administered into the deltoid or thigh instead of gluteal muscle. Deep intramuscular steroid injections must be given into the large muscles of the buttock.
Medication leakage – If the needle does not penetrate deep enough, the medication may leak into fatty tissue instead of being absorbed into muscle tissue, reducing its effectiveness.
Areas nearest to the heart (like the groin and the neck) have veins that are located near major arteries and nerves which, if accidentally hit, can cause serious, life-threatening damage. Injecting near a bone increases the chances that swelling and pain will occur.
Common complications:
Similarly, incorrect injection techniques or erroneous injection locations, can cause blood vessel breakage, muscle or nerve damage and paralysis. Harmful effects may be life-threatening at worst. Picture: Intramuscular injection gone wrong. Skin necrosis.
One of the most common errors in IM injection is introducing the needle either too high on the shoulder or too low on the arm. Injections given too high (into the shoulder joint) or too low (into tendons and soft tissue) have the possibility of leading to serious shoulder or arm pain that can last several months.
Call your health care provider right away if you have: A fever of 100.4°F (38°C) or higher, or as directed. Severe pain at the injection site. Blistering at the injection site.
It can cause irregular bleeding. The contraceptive injection changes the pattern of your bleeding. Your periods may stop or you might have irregular bleeding. This is when your bleeding does not happen at the same time each month.
As the amount of drug absorbed is dictated by the vascularity of the tissue in which the drug is injected, it therefore, follows that injecting a drug into fat results in slower and decreased absorption. Both injection technique and needle length determine how deep a substance is injected.
If you see blood in the syringe, it means you might have hit a blood vessel. This usually isn't harmful. If you see blood in the bottom of the syringe (hub) before you push in the plunger: Remove the needle without giving the medicine.
Diagnosis of High-Pressure Injection Injury
The site where the fluid penetrated the skin will typically resemble a pinhole-sized puncture, although in some cases, the point of entry is not visible at all (Nickson 2022; QAS 2021). Initially, the patient may only present with numbness or increased pressure.
Mild discomfort at the injection site is normal after most intramuscular injections, and symptoms like soreness or swelling usually resolve within a few days.
If you see blood in the syringe, you've hit a blood vessel. If this happens, pull the needle out of the skin without injecting the medicine. Discard the needle and syringe safely, such as in a special container for needles. Then prepare a new syringe with a new dose of medicine.
The sciatic nerve is the most commonly injured nerve because of an IM injection owing to its large size and the buttock being a common injection site.
Intramuscular injections commonly result in pain, redness, and swelling or inflammation around the injection site. These side effects are generally mild and last no more than a few days at most. Rarely, nerves or blood vessels around the injection site can be damaged, resulting in severe pain or paralysis.
Injections into the dorsogluteal site (buttock) will no longer be given because research has shown that the body does not always absorb the medication very well at this site.
Note: Dorsogluteal is not recommended as an injection site because of the sciatic nerve location. Ventrogluteal muscle: The ventrogluteal muscle is the preferred and safest IM injection site for all adults, children, and infants, especially for medications that have larger volumes and are more viscous and irritating.
After an intramuscular injection, patients may experience some discomfort, but most of them are normal signs. However, if you experience any of the following symptoms, medical attention is required: Tingling or numbness. Prolonged bleeding.
The most common needle size for IM injections is between 22G to 25G in width and 1 inch to 1.5 inches in length. The needle needs to be long enough to reach the muscle and wide enough to draw up and deliver the medication.