May the Z-Tracking Technique to Minimize or Avoid the Pain of Insulin Injection Be an Alternative to the 10-Second Waiting Technique?

Improving best practices in insulin injection technique is a main concern for both patients and the health care team. ¹ If the injection technique is incorrect, then it can result in pain, insulin leakage, bleeding, inflammation, bruising, lipoatrophy, and lipohypertrophy. ² Pain is perhaps the most common adverse event associated with insulin use.^3,4 Pain on injection may be caused by inaccurate injection technique; however, information is lacking concerning how to minimize the injection pain. Thus, the prompt mitigation of anxiety about and fear of pain and, if possible, mitigation of the actual pain are of great importance to the health care team. In seeking to understand injection pain, patient self-reports become very important. ³ In a study by Kalra and colleagues ² just over half of Indian injectors reported having pain on injection. In a study by Zijlstra and colleagues ⁴ large volume and thigh injections were rated as being more painful, but injection speed did not influence pain sensation.

Application of best practice technique in insulin delivery is an important aspect of a successful insulin therapy. ¹ Recent studies have indicated that leakage of liquid from the skin did not occur when administering subcutaneous tissue lateral to vertical lines drawn 5 cm away from the umbilicus with 30 units/mL in distilled water with shorter 4 mm prefilled pens needles by the Z technique. Studies have included both healthy volunteers and persons with diabetes, and their results have been consistent. This suggests that Z-tracking (the cutaneous tissues are pulled 2 cm caudad before inserting a 90° needle into the subcutaneous tissue after the button has been fully depressed, and then the needle is removed from the skin) may be an alternative to the 10-second hold in time (a 90° needle is directly inserted into the subcutaneous tissue and patients wait at least 10 seconds after the injection before the needle is withdrawn from the skin).^5,6

It was felt necessary to conduct this study to compare the effects on pain sensation of the 10-second waiting technique and the Z-track technique, which is claimed to be helpful in this regard.^5,6 Perceived injection pain sensation was assessed using a 10-cm visual analog scale (VAS) (0 cm/no pain, 10 cm/extreme pain). The study conducted by Demirhan et al ⁵ found that the healthy volunteers group using the Z technique had a mean perceived injection pain sensation with VAS was 0.3 ± 0.8 cm, whereas with the 10-second waiting technique these values were 0.9 ± 1.8 cm, respectively. In their other works, ⁶ these authors found that in the persons with diabetes group with the Z technique mean perceived injection pain sensation with VAS was 0.4 ± 1.1 cm, whereas with the standard 10- seconds waiting group these values were 1.5 ± 1.8 cm, respectively. When compared to the 10 seconds waiting technique, the Z-tract insertion technique demonstrated a significantly lower mean perceived injection pain sensation with VAS from the skin with subcutaneous injections. These results suggest that the Z-tract insertion technique plays an important role in reducing injection pain. Painless (as opposed to painful) subcutaneous insulin injections may increase treatment adherence. The results of this study may be of value for guiding patients to use the appropriate injection technique to reduce their injection pain.

To prevent pain sensation or minimize pain, an insulin injection should be performed with Z-tract technique insertion of a thin needle in the cutaneous tissues, rather than with a 10-second waiting technique.