ADA 2011: Dynamic Visual Representation of Key Data Helps Eliminate Hypoglycemia in the ICU

June 27, 2011
Jamie Reiter, PhD

Real-time blood sugar and insulin infusion data displayed in the electronic medical record allows physicians to tailor treatment and get more patients to goal.

Real-time blood sugar and insulin infusion data displayed in the electronic medical record allows physicians to tailor treatment and get more patients to goal.

In what seems like a long-overdue approach, researchers led by Kalman E. Holdy, MD, at Sharp Memorial Hospital developed a graphic assistance program in their ICU for use in glycemic management. Most hospitals rely on written protocols using single blood glucose (BG) measurements or computerized applications. However, written single measurements do not allow for pattern or trend recognition, and computers cannot make clinical judgment calls, especially for unstable levels or unusual patterns.

The Graphic assistant (GA) is an MPage in Sharp’s Cerner Millennium Power Chart electronic medical record and provides a “real-time representation of both blood sugar and last insulin infusion rate,” explained Holdy. Key features include a 48-hour graphic display of point of care BG (picture a line graph) and laboratory BG, a 48-hour graphic display of hourly IV insulin infusion rate (line graph), a horizontal shaded bar representing the ICU BG target for insulin infusions (100-150 mg/dl), and a spreadsheet/tabular presentation at two-hour increments of point-of-care BG, lab glucose level, IV insulin infusion rate, diet type, and percent consumed.

When considering all elements of continuous insulin infusion (CII) principles, it can become a daunting task to try to track and monitor BG and CII. ICU nurses have to navigate through three phases to maintain BG within a specified range. The first is a start-up phase to bring the BG initially into the target range, the second is a maintenance phase to keep BG’s in the target range, and the third is a transition off insulin infusion, usually to subcutaneous insulin. In addition to the three phases, there are key factors which need to be integrated within each insulin adjustment. These include absolute BG and absolute insulin infusion rate, rate of BG change and rate of insulin change, elapsed time between BG checks and CII adjustments, and the relationship of BG rate of change in response to the insulin rate of change. Clearly, having a dynamic visual representation as opposed to a written record of several variables can assist in managing BG.

The GA works by first observing BG, then deciding what to do about CII. Trends seen with GA can help predict the BG responses to CII changes. In addition to the BG value, rate of BG rise or fall can be observed, and the best CII adjustment can be estimated by “visually plotting” the CII rate which will maintain BG in the target range. By recognizing the rate of BG fall and adjusting CII accordingly, hypoglycemia can be minimized.

In the Sharp ICU, CII is provided to approximately 52 patients per month. Average time to reach target BG is 6 hours, and 70% of CII patients reach target within this time. Researchers compared the percent of patients with BG <40 mg/dl between the Sharp ICU and two Van Den Berghe 1 studies, VISEPS, and the NICE-SUGAR study. In the treatment groups of these latter studies, percentages ranged from 5.1% to 18.7%. However, at the Sharp ICU, 0.3% of patients had BG <40 mg/dl. Though not compared statistically, this observation supports the utility of the GA system.

Use of the GA system does require training, but it is similar to training for any CII system. However, it may be more challenging for nurses who are not visual learners, cautioned Holdy. While he is happy to continue using GA at his ICU, Holdy would be “happy to have other groups adopt it.”