Insulin Injection Technique and Site Rotation

An insulin injection is intended to deposit the prescribed dose in subcutaneous tissue, creating a depot from which insulin enters the circulation. Delivery into muscle instead of subcutaneous tissue can speed absorption, make the response less predictable, and increase the risk of severe hypoglycemia. Excessive pressure on a pen can also drive the needle deeper than intended. [1] The abdomen, lateral thighs, buttocks, and back of the upper arms contain usable subcutaneous areas. Human regular insulin is absorbed fastest from the abdomen; absorption from the upper arm and lateral thigh is moderate, and the buttock is slowest. Rapid-acting and long-acting analogues are less dependent on anatomical region. Consistency still matters: use the same anatomical region for a given time of day and rotate individual puncture sites within that region. [1] Technique matters with pens and with vials and syringes. Tissue selection, needle length, injection angle, priming, and the time the needle remains in the skin all affect whether the intended dose reaches the subcutaneous space. A reliable technique therefore supports predictable absorption; it does not replace checking the insulin order,...