Malfunction of continuous subcutaneous insulin infusion systems: a one-year prospective study of 127 patients.

Malfunction of portable continuous subcutaneous insulin infusion (CSII) systems may result in either ketoacidosis or serious hypoglycemia. To determine the types and frequencies of infusion system failure and the resulting clinical consequences, we recorded their occurrences in a 1-yr prospective study of 127 patients who were using insulin infusion pumps in a clinical practice setting. Of the 127 patients, 109 (86%) experienced at least one infusion system failure during the study. Most of the infusion system failures (96%) occurred in the syringe, infusion tube and connections, or subcutaneous infusion site. Virtually all malfunctions resulted in interruption of insulin flow, and most were associated with temporary loss of diabetes control. Equipment malfunction was documented in 6 of 7 patients who used insulin pumps and were treated in our hospital for diabetic ketoacidosis during the study. Pump "runaway" was not observed. We conclude that infusion system malfunction resulting in interruption of insulin flow is a common occurrence, is often associated with temporary hyperglycemia, and may account for some of the increased incidence of diabetic ketoacidosis previously described in these patients.

Clinical use of the insulin infusion pump in 100 patients with type I diabetes.

We investigated the efficacy of insulin-pump therapy in insulin-dependent diabetics, aged 18 to 69 years, by comparing the metabolic control achieved in 100 patients using this technique with that previously obtained by conventional insulin therapy. Patients were followed during pump therapy for as long as 15 months. Fasting and nonfasting blood glucose levels (mean +/- S.E.M.) decreased from 201 +/- 6 and 213 +/- 6 mg per deciliter (11.2 +/- 0.3 and 11.8 +/- 0.3 mmol per liter), respectively, to 158 +/- 5 and 145 +/- 3 mg per deciliter (8.77 +/- 0.3 and 8.05 +/- 0.2 mmol per liter) after one month of pump therapy (P less than 0.001). Ninety-three patients had improved blood sugar control; 71 per cent had a mean blood sugar concentration of 150 mg per deciliter (8.3 mmol per liter) or less after six months. Glycosylated hemoglobin values became normal in 44 per cent of 88 patients who had follow-up determinations. In over 500 patient-months there were four episodes of ketoacidosis and five episodes of serious hypoglycemia. Three patients abandoned pump therapy. We conclude that insulin-pump therapy is acceptable to patients and that it can be successfully applied to clinical practice and large-scale research studies.