Recurrent diabetic ketoacidosis after changing pen devices for insulin injection

Abstract

Diabetic ketoacidosis is a state of severe uncontrolled diabetes mellitus caused by severe insulin deficiency. It is characterised by hyperglycaemia, hyperketonaemia, and metabolic acidosis.1 Diabetic ketoacidosis is the leading cause of morbidity and mortality in children with type 1 diabetes mellitus,2 and in Western countries the overall mortality is 5-10%.1–3 Common precipitating causes include infection and inadequate dose of insulin resulting from non-adherence, failure to follow “sick day” rules (advice on increasing insulin during intercurrent illness), and poor injection technique.4 We have recently encountered two patients with recurrent diabetic ketoacidosis caused by unrecognised difficulty in switching from one type of prefilled insulin injection device to another. Fig 2 To administer insulin with the FlexPen, the dose is measured by dialling the appropriate number of units on the dose selector. The button is pushed to expel insulin via a needle attached to the clear barrel of the device. “Reverse dialling” of the dose selector does not expel insulin ### Case 1 A 68 year old man with type 1 diabetes mellitus was admitted to hospital with critically ischaemic feet. A vascular opinion deemed the right foot to be unsalvageable and an emergency below knee amputation was performed. Postoperatively the patient was stable and …