II. Technique

  1. Injection Locations
    1. Shoulder (Deltoid Muscle)
      1. Preferred injection site for age over 3 years
    2. Outer thigh (Vastus lateralis Muscle)
      1. Preferred injection site in under age 3 years
    3. Upper, outer aspect of buttock (gluteal Muscle)
      1. Identify landmarks and avoid sciatic nerve at inferior medial aspect
  2. Intramuscular Injection Needle
    1. Needle gauge: 22-25
      1. Aqueous medications: 22 to 25 gauge
      2. Thick solutions: 21 to 23 gauge
    2. Needle length varies by injection site (see below)
      1. Needles are typically 1 to 1.5 inches in teens and adults
  3. Thigh Intramuscular Injection
    1. Adequate needle length
      1. Needle 1 inch: Infants and Toddlers (age <3 years)
      2. Needle 1 to 1.25 inches: Age 3-10 years old
      3. Needle 1 to 1.5 inches: Age 11-18 years old
  4. Shoulder Injection (Deltoid)
    1. Adequate needle length
      1. Needle 5/8 inch: Weight <130 lb (60 kg)
      2. Needle 5/8 to 1 inch: Child <10 years old
      3. Needle 1 inch: Weight 130-152 lb (60 kg)
      4. Needle 1 to 1.5 inch
        1. Women: Weight 152-200 lb (70-90 kg)
        2. Men: Weight 152-260 lb (70-118 kg)
      5. Needle 1.5 inch
        1. Women: Weight >200 lb (>90 kg)
        2. Men: Weight >260 lb (>118 kg)
    2. Injectors arms should be at same height as patient's Shoulder
      1. Ensures injection will enter skin at 90 degrees (perpendicular) with less risk of injury
    3. Injection site
      1. Inject at central, thickest region of deltoid, below bony Shoulder by 2 inches (or 2-3 finger breadths)
    4. Complications
      1. Soft Tissue Injury (e.g. tendon, ligament, bursa) if injection placed too high in Shoulder
      2. Shoulder Injury Related to Vaccine Administration (SIRVA)
        1. Bancsi (2019) Can Fam Physician 65(1): 40-2 [PubMed]

III. Precautions

  1. Allow medication dose to warm to room Temperature before infection (reduces pain)
  2. Patients should dispose of needles in sharps container (NOT the trash)
  3. Avoid frequent site reuse due to injection site fibrosis risk
    1. Rotate injection sites
  4. Injection should be at 90 degrees to skin surface
  5. Avoid rubbing injection area after injection
  6. Encourage use of limb after injection to prevent freezing symptoms from dissuse
    1. Injection in the dominant arm Shoulder may ensure greater use
    2. Cool compresses may be used to reduce discomfort after injection
      1. Consider ice to area for 10 min prior to injection
    3. Ibuprofen or Acetaminophen may be used for discomfort
      1. Avoid premedication as very weak data suggests Vaccines may be less effective after Analgesics

IV. Efficacy

  1. Many standard IM medication uses are no more effective than their oral counterparts
    1. Vitamin B12 Replacement
    2. Ketorolac (Toradol)
    3. Corticosteroids
    4. Ceftriaxone in cases of refractory Otitis Media or Urinary Tract Infections in children
    5. Shatsky (2009) Am Fam Physician 79(4):297-300 [PubMed]

V. Contraindications: Relative

VIII. References

  1. (2021) Presc Lett 28(12):70
  2. (2021) Presc Lett 28(3): 13-4

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Related Studies

Ontology: Intramuscular injection (C0021492)

Definition (HL7V3.0) <p>Injection, intramuscular</p>
Definition (HL7V3.0) <p>Injection, intramuscular</p>
Definition (NCI) Intramuscular injection is a route of drug administration via injection into muscle tissue. Aqueous or oleaginous solutions and emulsions or suspensions may be administered. Absorption rates, delay in availability of the drug to the systemic circulation, and duration of effect are perfusion-limited, depend on molecular size of the agent, volume, and osmolarity of the drug solution, fat content of the injection site, and patient physical activity.
Definition (NCI_CDISC) Administration within a muscle. (FDA)
Definition (CSP) administration of a drug via injection into a muscle.
Definition (MSH) Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.
Concepts Functional Concept (T169)
MSH D007273
SnomedCT 180250003, 180243002, 76601001
HL7 2.16.840.1.113883.1.11.14657, IM
LNC LA11323-5
English Injection, Intramuscular, Injections, Intramuscular, Intramuscular Injections, Intramuscular drug therapy, Intramuscular injection NOS, Intramuscular Injection, INTRAMUSCULAR, Intramuscular Route of Administration, INJECT INTRAMUSCULAR, INTRAMUSCULAR INJECT, IM injection, im injections, intramuscular injections, intramuscular (IM) injections, im injection, IntramuscularInjection, Intramuscular injection NOS (procedure), IM, intramuscular injection, Intramuscular, Injection, intramuscular, IM - Intramuscular injection, IMI - Intramuscular injection, Intramuscular injection (procedure), Intramuscular injection
Swedish Injektioner, intramuskulära
Czech injekce intramuskulární
Finnish Lihaksensisäiset injektiot
French Injections musculaires, Injections intramusculaires, Injections intra-musculaires
Italian Iniezioni intramuscolari
Polish Wstrzyknięcia domięśniowe
Japanese 筋注, 筋肉内注射, 注射-筋肉内, 筋内注, 筋内注射, 筋肉注, 筋肉注射
Norwegian Injeksjoner, intramuskulære, Intramuskulære injeksjoner
Spanish inyección intramuscular, SAI, inyección intramuscular, SAI (procedimiento), inyección intramuscular (procedimiento), inyección intramuscular, Inyecciones Intramusculares
German Injektionen, intramuskuläre, Intramuskuläre Injektionen
Dutch Injectie, intramusculaire, Injecties, intramusculaire, Intramusculaire injectie
Portuguese Injeções Intramusculares