An intravenous insulin protocol for strict glycemic control in acute ischaemic stroke

There is a J-shaped association between admission glycemia and outcome. We designed an intravenous insulin protocol aiming at rapid and strict glucose control in hyperglycemic ischaemic stroke patients. Here, we describe the initial experience, safety, and efficacy of this protocol to achieve and maintain euglycemia in the first 48h.

The protocol is based on parallel scales for adjustment of insulin infusion rate according to current glycemia and the rate of change of glycemia, which was recommended in our stroke unit in 4/2007 in acute ischaemic stroke patients with glycemia >6mM. Data were registered in the Acute Stroke Registry and Analysis of Lausanne (ASTRAL). Capillary blood glycemia was measured hourly with fingerprick test at onset of treatment and after each scale change. Target glycemia was 4.0-6.0mM pre-prandially (5.5-8.0mM post-prandially). Hypokalemia was defined as serum potassium <3.5mM and measured every 12h. Specific algorithms were employed during meals and for patients leaving temporarily the stroke unit for diagnostic or therapeutic workup.

In the 90 protocol patients, the first normoglycemia was achieved within 8h of treatment in 91.1% of patients (median interval 4h (interquartile range (IQR): 3-6). During the median treatment duration of 25.5h (IQR: 19.7-37.7), median glucose reduction was 2.5mM (IQR: 1.3-4.3mM). The overall rate of hypoglycemias was 4.5% and hypokalemias 18.5%. There was a significant increase in the proportion of hypokalemias on the first on-treatment measurement compared to admission (24.4% vs. 8.9%, P=0.002).

The proposed intravenous insulin protocol controls acute post-stroke hyperglycemia but frequently leads to hypokalemia. This issue needs to be addressed for the protocol to be suitable for use in larger, randomized controlled trial to explore its clinical effect.