Intramuscular injection | |
---|---|
ICD-10-PCS | 3E023 |
ICD-9-CM | 99.1 |
MeSH | D007273 |
CPT | 96372 |
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles have larger and more numerous blood vessels than subcutaneous tissue, leading to faster absorption than subcutaneous or intradermal injections. Medication administered via intramuscular injection is not subject to the first-pass metabolism effect which affects oral medications.
Common sites for intramuscular injections include the deltoid muscle of the upper arm and the gluteal muscle of the buttock. In infants, the vastus lateralis muscle of the thigh is commonly used. The injection site must be cleaned before administering the injection, and the injection is then administered in a fast, darting motion to decrease the discomfort to the individual. The volume to be injected in the muscle is usually limited to 2–5 milliliters, depending on injection site. A site with signs of infection or muscle atrophy should not be chosen. Intramuscular injections should not be used in people with myopathies or those with trouble clotting.
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. If proper technique is not followed, intramuscular injections can result in localized infections such as abscesses and gangrene. While historically aspiration, or pulling back on the syringe before injection, was recommended to prevent inadvertent administration into a vein, it is no longer recommended for most injection sites by some countries.
Intramuscular injection is commonly used for medication administration. Medication administered in the muscle is generally quickly absorbed in the bloodstream, and avoids the first pass metabolism which occurs with oral administration. [1] The medication may not be considered 100% bioavailable as it must still be absorbed from the muscle, which occurs over time. [2] : 102–103 An intramuscular injection is less invasive than an intravenous injection and also generally takes less time, as the site of injection (a muscle versus a vein) is much larger. Medications administered in the muscle may also be administered as depot injections, which provide slow, continuous release of medicine over a longer period of time. [3] Certain substances, including ketamine, may be injected intramuscularly for recreational purposes. [4] Disadvantages of intramuscular administration include skill and technique required, pain from injection, anxiety or fear (especially in children), and difficulty in self-administration which limits its use in outpatient medicine. [5]
Vaccines, especially inactivated vaccines, are commonly administered via intramuscular injection. [6] However, it has been estimated that for every vaccine injected intramuscularly, 20 injections are given to administer drugs or other therapy. [6] This can include medications such as antibiotics, immunoglobulin, and hormones such as testosterone and medroxyprogesterone. [5] In a case of severe allergic reaction, or anaphylaxis, a person may use an epinephrine autoinjector to self-administer epinephrine into the muscle. [7]
Because an intramuscular injection can be used to administer many types of medications, specific contraindications depend in large part on the medication being administered. [8] Injections of medications are necessarily more invasive than other forms of administration such as by mouth or topical and require training to perform appropriately, without which complications can arise regardless of the medication being administered. For this reason, unless there are desired differences in rate of absorption, time to onset, or other pharmacokinetic parameters in the specific situation, a less invasive form of drug administration (usually by mouth) is preferred. [8]
Intramuscular injections are generally avoided in people with low platelet count or clotting problems, to prevent harm due to potential damage to blood vessels during the injection. They are also not recommended in people who are in hypovolemic shock, or have myopathy or muscle atrophy, as these conditions may alter the absorption of the medication. [5] The damage to the muscle caused by an intramuscular injections may interfere with the accuracy of certain cardiac tests for people with suspected myocardial infarction and for this reason other methods of administration are preferred in such instances. [5] In people with an active myocardial infarction, the decrease in circulation may result in slower absorption from an IM injection. [9] : 368–369 Specific sites of administration may also be contraindicated if the desired injection site has an infection, swelling, or inflammation. [9] : 368–369 Within a specific site of administration, the injection should not be given directly over irritation or redness, birthmarks or moles, or areas with scar tissue. [9] : 368–369
As an injection necessitates piercing the skin, there is a risk of infection from bacteria or other organisms present in the environment or on the skin before the injection. This risk is minimized by using proper aseptic technique in preparing the injection and sanitizing the injection site before administration. [9] : 369 Intramuscular injections may also cause an abscess or gangrene at the injection site, depending on the specific medication and amount administered. There is also a risk of nerve or vascular injury if a nerve or blood vessel is inadvertently hit during injection. If single-use or sterilized equipment is not used, there is the risk of transmission of infectious disease between users, or to a practitioner who inadvertently injures themselves with a used needle, termed a needlestick injury. [5] [9] : 372
Injections into the deltoid site in the arm can result in unintentional damage to the radial and axillary nerves. In rare cases when not performed properly, the injection may result in shoulder dysfunction. [10] The most frequent complications of a deltoid injection include pain, redness, and inflammation around the injection site, which are almost always mild and last only a few days at most. [11]
The dorsogluteal site of injection is associated with a higher risk of skin and tissue trauma, muscle fibrosis or contracture, hematoma, nerve palsy, paralysis, and infections such as abscesses and gangrene. [12] Furthermore, injection in the gluteal muscle poses a risk for damage to the sciatic nerve, which may cause shooting pain or a sensation of burning. Sciatic nerve damage can also affect a person's ability to move their foot on the affected side, and other parts of the body controlled by the nerve. Damage to the sciatic nerve can be prevented by using the ventrogluteal site instead, and by selecting an appropriate size and length of needle for the injection. [13]
An intramuscular injection can be administered in multiple different muscles of the body. Common sites for intramuscular injection include: deltoid, dorsogluteal, rectus femoris, vastus lateralis and ventrogluteal muscles. [12] [14] Sites that are bruised, tender, red, swollen, inflamed or scarred are generally avoided. [15] The specific medication and amount being administered will influence the decision of the specific muscle chosen for injection.
The injection site is first cleaned using an antimicrobial and allowed to dry. The injection is performed in a quick, darting motion perpendicular to the skin, at an angle between 72 and 90 degrees. The practitioner will stabilize the needle with one hand while using their other hand to depress the plunger to slowly inject the medication – a rapid injection causes more discomfort. The needle is withdrawn at the same angle inserted. Gentle pressure may be applied with gauze if bleeding occurs. [16] Pressure or gentle massage of the muscle following injection may reduce the risk of pain. [17]
Aspirating for blood to rule out injecting into a blood vessel is not recommended by the US CDC, Public Health Agency of Canada, or Norway Institute of Public Health, as the injection sites do not contain large blood vessels and aspiration results in greater pain. [18] [19] [20] There is no evidence that aspiration is useful to increase safety of intramuscular injections when injecting in a site other than the dorsogluteal site. [6]
Aspiration was recommended by the Danish Health Authority for COVID-19 vaccines for a time to investigate the potential rare risk of blot clotting and bleeding, but it is no longer a recommendation. [21] [22]
The Z-track method is a method of administering an IM injection that prevents the medication being tracked through the subcutaneous tissue, sealing the medication in the muscle, and minimizing irritation from the medication. Using the Z-track technique, the skin is pulled laterally, away from the injection site, before the injection; then the medication is injected, the needle is withdrawn, and the skin is released. This method can be used if the overlying tissue can be displaced. [23]
The deltoid muscle in the outer portion of the upper arm is used for injections of small volume, usually equal to or less than 2 mL. This includes most intramuscular vaccinations. [12] It is not recommended to use the deltoid for repeated injections due to its small area, which makes it difficult to space out injections from each other. [12] The deltoid site is located by locating the lower edge of the acromion process, and injecting in the area which forms an upside down triangle with its base at the acromion process and its midpoint in line with the armpit. [15] An injection into the deltoid muscle is commonly administered using a 1-inch long needle, but may use a 5⁄8-inch long needle for younger people or very frail elderly people. [11]
The ventrogluteal site on the hip is used for injections which require a larger volume to be administered, greater than 1 mL, and for medications which are known to be irritating, viscous, or oily. It is also used to administer narcotic medications, antibiotics, sedatives and anti-emetics. [12] The ventrogluteal site is located in a triangle formed by the anterior superior iliac spine and the iliac crest, and may be located using a hand as a guide. [15] The ventrogluteal site is less painful for injection than other sites such as the deltoid site. [17]
The vastus lateralis site is used for infants less than 7 months old and people who are unable to walk or who have loss of muscular tone. [12] The site is located by dividing the front thigh into thirds vertically and horizontally to form nine squares; the injection is administered in the outer middle square. [15] This site is also the usual site of administration for epinephrine autoinjectors, which are used in the outer thigh, corresponding to the location of the vastus lateralis muscle. [24]
The dorsogluteal site of the buttock site is not routinely used due to its location near major blood vessels and nerves, as well as having inconsistent depth of adipose tissue. [25] Many injections in this site do not penetrate deep enough under the skin to be correctly administered in the muscle. [12] [26] While current evidence-based practice recommends against using this site, many healthcare providers still use this site, often due to a lack of knowledge about alternative sites for injection. [27] This site is located by dividing the buttock into four using a cross shape, and administering the injection in the upper outer quadrant. This is the only intramuscular injection site for which aspiration is recommended of the syringe before injection, due to higher likelihood of accidental intravenous administration in this area. [12] However, aspiration is not recommended by the Centers for Disease Control and Prevention, which considers it outdated for any intramuscular injection. [16]
Some populations require a different injection site, needle length, or technique. In very young or weak elderly patients, a normal-length needle may be too long to inject properly. In these patients, a shorter needle is indicated to avoid injecting too deeply. [28] It is also recommended to consider using the anterolateral thigh as an injection site in infants under one year old. [28]
To help infants and children cooperate with injection administration, the Advisory Committee on Immunization Practices in the United States recommends using distractions, giving something sweet, and rocking the baby side to side. In people who are overweight, a 1.5-inch needle may be used to ensure the injection is given below the subcutaneous layer of skin, while a 5⁄8-inch needle may be used for people who weigh under 60 kilograms (130 lb). In any case, the skin does not need to be pinched up before injecting when the appropriate length needle is used. [29]
Injections into muscular tissue may have taken place as early as the year 500 AD. Beginning in the late 1800s, the procedure began to be described in more detail and techniques began to be developed by physicians. In the early days of intramuscular injections, the procedure was performed almost exclusively by physicians. [8] After the introduction of antibiotics in the middle of the 20th century, nurses began preparing equipment for intramuscular injections as part of their delegated duties from physicians, and by 1961 they had "essentially taken over the procedure". [8] Until this delegation became virtually universal, there were no uniform procedures or education for nurses in proper administration of intramuscular injections, and complications from improper injection were common. [8]
Intramuscular injections began to be used for administration of vaccines for diphtheria in 1923, whooping cough in 1926, and tetanus in 1927. [30] By the 1970s, researchers and instructors began forming guidance on injection site and technique to reduce the risk of injection complications and side effects such as pain. [8] Also in the early 1970s, botulinum toxin began to be injected into muscles to intentionally paralyze them for therapeutic reasons, and later for cosmetic reasons. [31] Until the 2000s, aspiration after inserting the needle was recommended as a safety measure, to ensure the injection was being administered in a muscle and not inadvertently in a vein. However, this is no longer recommended as evidence shows no safety benefit and it lengthens the time taken for injection, which causes more pain. [29]
In animals common sites for intramuscular injection include the quadriceps, the lumbodorsal muscles, and the triceps muscle. [32]
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of the use of emergency medication on site. It typically causes more than one of the following: an itchy rash, throat closing due to swelling that can obstruct or stop breathing; severe tongue swelling that can also interfere with or stop breathing; shortness of breath, vomiting, lightheadedness, loss of consciousness, low blood pressure, and medical shock. These symptoms typically start in minutes to hours and then increase very rapidly to life-threatening levels. Urgent medical treatment is required to prevent serious harm and death, even if the patient has used an epipen or has taken other medications in response, and even if symptoms appear to be improving.
A local anesthetic (LA) is a medication that causes absence of all sensation in a specific body part without loss of consciousness, providing local anesthesia, as opposed to a general anesthetic, which eliminates all sensation in the entire body and causes unconsciousness. Local anesthetics are most commonly used to eliminate pain during or after surgery. When it is used on specific nerve pathways, paralysis also can be induced.
Intravenous therapy is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use.
An autoinjector is a medical device designed to deliver a dose of a particular drug. The injectors were initially designed to overcome the hesitation associated with self-administration of the needle-based drug delivery device.
A hypodermic needle, one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used with a syringe, a hand-operated device with a plunger, to inject substances into the body or extract fluids from the body. Large-bore hypodermic intervention is especially useful in catastrophic blood loss or treating shock.
In pharmacology and toxicology, a route of administration is the way by which a drug, fluid, poison, or other substance is taken into the body.
Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.
An injection is the act of administering a liquid, especially a drug, into a person's body using a needle and a syringe. An injection is considered a form of parenteral drug administration; it does not involve absorption in the digestive tract. This allows the medication to be absorbed more rapidly and avoid the first pass effect. There are many types of injection, which are generally named after the body tissue the injection is administered into. This includes common injections such as subcutaneous, intramuscular, and intravenous injections, as well as less common injections such as intraperitoneal, intraosseous, intracardiac, intraarticular, and intracavernous injections.
Epidural administration is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and nurse anesthetists to administer local anesthetic agents, analgesics, diagnostic medicines such as radiocontrast agents, and other medicines such as glucocorticoids. Epidural administration involves the placement of a catheter into the epidural space, which may remain in place for the duration of the treatment. The technique of intentional epidural administration of medication was first described in 1921 by Spanish military surgeon Fidel Pagés.
A jet injector is a type of medical injecting syringe device used for a method of drug delivery known as jet injection. A narrow, high-pressure stream of liquid is made to penetrate the outermost layer of the skin to deliver medication to targeted underlying tissues of the epidermis or dermis, fat, or muscle.
Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block is a short-term block, usually lasting hours or days, involving the injection of an anesthetic, a corticosteroid, and other agents onto or near a nerve. Neurolytic block, the deliberate temporary degeneration of nerve fibers through the application of chemicals, heat, or freezing, produces a block that may persist for weeks, months, or indefinitely. Neurectomy, the cutting through or removal of a nerve or a section of a nerve, usually produces a permanent block. Because neurectomy of a sensory nerve is often followed, months later, by the emergence of new, more intense pain, sensory nerve neurectomy is rarely performed.
Intracardiac injections are injections that are given directly into the heart muscles or ventricles. They can be used in emergencies, although they are rarely used in modern practice.
Drug injection is a method of introducing a drug into the bloodstream via a hollow hypodermic needle, which is pierced through the skin into the body. Intravenous therapy, a form of drug injection, is universally practiced in modernized medical care. As of 2004, there were 13.2 million people worldwide who self-administered injection drugs outside of medical supervision, of which 22% are from developed countries.
In medicine, a bolus is the administration of a discrete amount of medication, drug, or other compound within a specific time, generally 1–30 minutes, to raise its concentration in blood to an effective level. The administration can be given by injection: intravenously, intramuscularly, intrathecally, subcutaneously, or by inhalation. The article on routes of administration provides more information, as the preceding list of ROAs is not exhaustive.
Veterinary anesthesia is a specialization in the veterinary medicine field dedicated to the proper administration of anesthetic agents to non-human animals to control their consciousness during procedures. A veterinarian or a Registered Veterinary Technician administers these drugs to minimize stress, destructive behavior, and the threat of injury to both the patient and the doctor. The duration of the anesthesia process goes from the time before an animal leaves for the visit to the time after the animal reaches home after the visit, meaning it includes care from both the owner and the veterinary staff. Generally, anesthesia is used for a wider range of circumstances in animals than in people not only due to their inability to cooperate with certain diagnostic or therapeutic procedures, but also due to their species, breed, size, and corresponding anatomy. Veterinary anesthesia includes anesthesia of the major species: dogs, cats, horses, cattle, sheep, goats, and pigs, as well as all other animals requiring veterinary care such as birds, pocket pets, and wildlife.
Dental anesthesia is the application of anesthesia to dentistry. It includes local anesthetics, sedation, and general anesthesia.
Injection site reactions (ISRs) are reactions that occur at the site of injection of a drug. They may be mild or severe and may or may not require medical intervention. Some reactions may appear immediately after injection, and some may be delayed. Such reactions can occur with subcutaneous, intramuscular, or intravenous administration.
Vitamin K reactions are adverse side effects that may occur after injection with vitamin K. The liver utilizes vitamin K to produce coagulation factors that help the body form blood clots which prevent excessive bleeding. Vitamin K injections are administered to newborns as a preventative measure to reduce the risk of hemorrhagic disease of the newborn (HDN).
Intradermal injection is a shallow or superficial injection of a substance into the dermis, which is located between the epidermis and the hypodermis. For certain substances, administration via an ID route can result in a faster systemic uptake compared with subcutaneous injections, leading to a stronger immune response to vaccinations, immunology and novel cancer treatments, and faster drug uptake. Additionally, since administration is closer to the surface of the skin, the body's reaction to substances is more easily visible. However, due to complexity of the procedure compared to subcutaneous injection and intramuscular injection, administration via ID is relatively rare, and is only used for tuberculosis and allergy tests, Monkeypox vaccination, and certain therapies.
An injector pen is a device used for injecting medication under the skin. First introduced in the 1980s, injector pens are designed to make injectable medication easier and more convenient to use, thus increasing patient adherence. The primary difference between injector pens and traditional vial and syringe administration is the easier use of an injector pen by people with low dexterity, poor vision, or who need portability to administer medicine on time. Injector pens also decrease the fear or adversity towards self-injection of medications, which increases the likelihood that a person takes the medication.
Aspiration is not recommended before administering a vaccine.
Aspiration before injection of vaccine is not recommended, as there are no large blood vessels at the recommended immunization sites and not aspirating before injection has been demonstrated to reduce pain.
However, it is not recommended to aspirate before intramuscular and subcutaneous vaccine injection provided that the vaccine is placed in the appropriate place … does not involve the risk of injecting intravenously because there are no large blood vessels in these sites. Aspiration can cause the vaccination to be more painful because it takes longer to give the vaccine
The Danish Health and Medicines Authority's guidelines have long recommended this, and now the Statens Serum Institut is following suit.
It has previously been recommended to aspirate before injection with Covid-19 vaccines in relation to investigation of a possible connection between injection with Vaxzevria® and the occurrence of rare and serious side effects. However, this is no longer a recommendation and Covid-19 vaccines can be injected without prior aspiration.