What is the maximum volume of medication that can be administered in a deltoid (intramuscular) injection?

Maximum Volume for Deltoid Intramuscular Injection

For adults, the deltoid muscle can accommodate up to 1 mL (1.0 mL) for routine intramuscular injections, though standard vaccine doses of 0.5 mL are most commonly recommended.

Volume Guidelines by Age Group

Adults (≥18 years)

• Standard vaccine volume: 0.5 mL is the typical dose for most intramuscular vaccines administered in the deltoid 1
• Maximum volume: 1 mL can be safely administered in the deltoid muscle for medications 2
• The deltoid is the preferred site for routine intramuscular vaccinations in adults 1

Children and Adolescents (>12 months to 18 years)

• Volume: 0.5 mL for children aged ≥36 months receiving intramuscular preparations 1
• Volume: 0.25 mL for children aged 6-35 months (specific to certain vaccine formulations like Fluzone Quadrivalent) 1
• The deltoid can be used if muscle mass is adequate; otherwise, the anterolateral thigh is preferred 1

Infants (<12 months)

• The anterolateral thigh is the recommended site, not the deltoid 1
• The deltoid may be used in infants only when multiple vaccines must be administered at the same visit 1

Technical Considerations

Needle Specifications for Deltoid Injection

• Adults: 1 to 1½ inches in length, 22-25 gauge 1
• Children: 7/8 to 1¼ inches, 22-25 gauge (based on muscle size) 1
• The needle must be long enough to reach muscle mass but not so long as to endanger underlying neurovascular structures 1

Multiple Injections

• When administering multiple injections in the deltoid, injections should be sufficiently separated (>1 inch) so local reactions can be differentiated 1
• Some experts recommend no more than two injections per muscle, separated by at least one inch 3
• Each vaccine should be administered using a separate syringe at a different anatomic site 3

Critical Safety Points

Anatomical Considerations

• Injection site location: The safest site is 4 fingerbreadths (approximately 9 cm) below the mid-acromion point to avoid injury to the axillary nerve and posterior circumflex humeral artery 4
• Never inject in the upper half of the deltoid muscle to prevent neurovascular injury 4
• The mean distance of the axillary nerve from the mid-acromial point is approximately 8.2 cm 4

Administration Technique

• Injections should be administered at a 90-degree angle into the deltoid muscle 1
• Aspiration before injection is not required based on current evidence, though some practitioners continue this practice 1
• The deltoid provides adequate muscle mass for absorption and is more accessible than the gluteal site 5

Common Pitfalls to Avoid

• Do not use volumes exceeding 1 mL in the deltoid, as larger volumes may cause discomfort and are better suited for the gluteal or anterolateral thigh sites 1
• Avoid the buttock for routine vaccinations due to risk of sciatic nerve injury and decreased immunogenicity 1
• Do not administer vaccines containing adjuvants subcutaneously or intradermally, as they can cause local irritation and granuloma formation 1

Post-Injection Monitoring

• Observe patients for 15 minutes after vaccination, especially adolescents and young adults, due to syncope risk 3
• Take appropriate measures to prevent potential injuries from syncope 3