Ultra-structural evaluation of needles and their role for comfort during subcutaneous drug administration.

Objective To evaluate the morphology of hypodermic needle bevels after drug aspiration, and the perception of comfort caused by the change or not of needles between preparation and subcutaneous drug administration. Method Experimental research carried out in two moments. Initially, hypodermic needles were analyzed by scanning electron microscopy, and then a pilot trial was conducted with the participants, which indicated the level of comfort perceived at the time of needle bevel penetration during subcutaneous administration. Results Forty-one adult inpatients participated in the study. Although the needles presented a slight to significant morphological alteration when evaluated by ultramicroscopy, the participants in this study were not able to report significant sensory changes during their penetration in the two techniques used. Conclusions The standardization of fixed needle syringes, or the use of a single needle for both the preparation and the subcutaneous drug administration should be considered as strategies to reduce the production of sharp-perforating residues, to decrease the cost per procedure, and to limit the risk of contamination of critical devices.