[Choosing an intramuscular injection needle according to body type]

Area of Science:

• Medical Science
• Anatomy
• Pharmacology

Background:

• Intramuscular injections require accurate needle selection for efficacy.
• Patient body types (habitus) can influence subcutaneous fat thickness.
• Inappropriate needle length may lead to suboptimal drug delivery and adverse effects.

Purpose of the Study:

• To determine the optimal needle length for intramuscular injections based on patient body type.
• To compare the effectiveness of different needle lengths in relation to patient habitus.
• To reduce local pain and tissue hardening after intramuscular injections.

Main Methods:

• Measurement of hypodermic fat thickness at the dorsogluteal site.
• Inclusion of 360 patients categorized by asthenic, sthenic, or ortho-sthenic body types.
• Comparative analysis of injection outcomes with varying needle lengths.

Main Results:

• Standard needles (No. 6.5 and No. 7) are inadequate for elderly females with ortho-sthenic type and for sthenic patients.
• Needle lengths of 35 mm, 40 mm, and 45 mm are recommended for specific sthenic and ortho-sthenic patient groups.
• Appropriate needle selection ensures deeper tissue penetration for effective intramuscular administration.

Conclusions:

• Patient habitus is a critical factor in selecting intramuscular injection needle length.
• Tailoring needle selection to body type improves therapeutic outcomes.
• Using appropriate needle lengths minimizes post-injection complications such as pain and tissue hardening.