An unexpected hazard of insulin injection

Abstract

In the October 2001 issue, your Diabetes Vignette illustrated the breaking off in a patient's arm of a pen needle that had been bent during a previous injection and then straightened by the patient prior to reusing the needle. It is stated that Becton Dickinson is not aware of any similar cases. Unfortunately, this is not correct. Every year we learn of a certain number of cases strikingly similar to that of your patient. The patient assumes that it is safe to reuse the needle and, as a consequence, bending occurs which can lead to breakage. Often the needle breaks outside the body and is easily retrieved, occasionally it stays inside, leading to considerable anguish on the part of the patient and confusion as to the appropriate medical/surgical management. Bending can occur both microscopically (blunting of the needle tip) and macroscopically (deviation at the hub). The former often leads to the latter, and both are implicated in the breakage of the needle. The context in which this occurs is invariably the reuse of the needle. Often the patient is unaware of the risk, has been encouraged to reuse by nurses, doctors or fellow patients and does not notice the bending with the naked eye. All needles, from all manufacturers, whether for syringes or pen devices, are susceptible to bending and breaking, in the context of needle reuse. In our product labeling we instruct patients to use needles only once and then discard them. The reasons are multiple, but among them is the avoidance of breakage risk. Furthermore, there is also a possible association between the use of deformed needles and the pathogenesis of lipodystrophy. On this basis, in their Nov. 2001 Position statement1 the ADA has withdrawn their former statement “For many patients, it appears both safe and practical for the syringe to be reused if the patient so desires”. Two other elements of this case are worthy of comment. Firstly, in this patient the needle was clearly visible on X-ray and surgical retrieval was successful. However, most often one is unable to see the needle by radiographic means and in that case surgical exploration has a much lower rate of success and probably should not be attempted. Rather the patient should be reassured that the needle is made from the same materials as steel surgical sutures or implants, that migration of the needle into a vital organ or embolisation into the vascular tree has never been reported, and that, given time, the needle will work its way to the skin surface or will be harmlessly walled off by fibrous reaction. Secondly, a 12.7 mm (half inch) needle was used for an arm injection in your case. It is not stated whether the patient pinched up a skin fold into which she injected. This is the recommended procedure when using this needle in the arm, but anyone who has tried to pinch a fold and inject into it at the same time will tell you that such a maneuver in the arm is nearly impossible. An alternative practice would have been to use shorter insulin pen needles (e.g. 5 mm), which are designed to avoid inadvertent intra-muscular injections, do not require pinching the arm and have been shown to be equally effective in insulin therapy. Injecting is both a science and an art, which, once mastered, can enhance the effectiveness of insulin therapy as much as using the correct dose. Ken Strauss*, * European Medical Director, Becton Dickinson, Denderstraat 24 - POB 13, B-9320 Erembodegem-Aalst, Belgium