What is the maximum volume of fluid that can be injected into a muscle?

Maximum Volume for Intramuscular Injections

The maximum recommended volume for intramuscular injections in adults is 5 mL in the gluteal region, with smaller volumes (2-3 mL) recommended for routine clinical practice to minimize pain and tissue damage. 1

Volume Limitations by Injection Site and Age

Different muscle groups can accommodate different volumes of medication:

Adults:

• Gluteal site (ventrogluteal/dorsogluteal): Maximum 5 mL, but 2-3 mL is preferred for routine practice 1
• Deltoid muscle: 0.5-2 mL
• Anterolateral thigh (vastus lateralis): 1-5 mL

Children:

• Infants (<12 months): Maximum 1 mL per injection site 2
• Toddlers (1-2 years): 1-2 mL
• Older children: Volume based on muscle mass development

Injection Site Selection

The choice of injection site should be based on:

1. Volume of medication to be administered
2. Patient's age and muscle mass
3. Type of medication (irritant medications require larger muscle mass)

For larger volumes:

• The gluteal region is preferred in adults due to larger muscle mass
• The anterolateral thigh is preferred in infants and young children 3

Best Practices for Intramuscular Injections

• Use appropriate needle length to ensure the medication reaches the muscle:

  • Adults: 1-1½ inches, 22-25 gauge for gluteal and thigh injections 3
  • Children: 7/8-1 inch, 22-25 gauge, depending on size 3

• Multiple injections: If more than 5 mL total volume is needed, divide into multiple injections at different sites, separated by at least 1 inch 3

• Z-track technique: Recommended for irritant medications to prevent leakage into subcutaneous tissue

Common Pitfalls and Complications

• Exceeding maximum volumes can cause:

  • Increased pain
  • Tissue damage
  • Poor medication absorption
  • Risk of leakage into subcutaneous tissue

• Incorrect site identification: Particularly in the gluteal region, can lead to sciatic nerve injury 4

• Inadequate needle length: Results in subcutaneous rather than intramuscular administration, potentially affecting drug efficacy 3

• Bleeding complications: Generally rare (0.02% in anticoagulated patients) but should be considered in patients on anticoagulants 5

Special Considerations

• For patients receiving frequent injections, rotate injection sites to prevent tissue damage
• Consider patient comfort and medication properties when selecting injection site and volume
• Medication-specific recommendations may override general guidelines (e.g., certain long-acting medications have specific volume requirements) 1

Remember that using the smallest effective volume minimizes patient discomfort while maintaining therapeutic efficacy. The 5 mL maximum for adults (gluteal region) should be considered an upper limit rather than a routine target volume.