Aspiration of the subcutaneous insulin injection: clinical evaluation of needle size and amount of subcutaneous fat.

Investigating the rationale for a particular technique can reveal the surprising finding that some techniques are not based on scientific research. Aspiration of the insulin syringe is an example of a technique that evolved based on assumption. In a study designed to challenge the need to aspirate during insulin administration, 204 injections that were aspirated yielded no blood return. The historical and research literature supports the finding that aspiration never was proven to be a reliable indicator of correct subcutaneous needle placement. Because inadvertent intramuscular injection of insulin has been documented, diabetes educators need a reliable method to individualize insulin administration techniques to decrease the risk of incorrect needle placement. Until a reliable method is available, the literature supports lifting a skinfold for all subcutaneous insulin injections.