Improving Glycemic Control for Post-Operative Cardiac Surgery Patients: An NP-Led Project

Monday, 9 November 2015

Linda Sue Kerr, MSN, RN, FNP-BC, CDE
Peggy Kalowes, PhD, MSN, RN, RN, CNS, FAHA
Barbara Lynn Easterbrook, MSN, BSN, ADN, AA, RN, ANP
Darice Hawkins, MN, BSN, RN, CCRN, CMC, CSC
Long Beach Memorial, Long Beach, CA, USA

Background and Significance

Inpatient diabetes care consumes half of the $174 billion total expenditures for diabetes in the United States.  According to studies, patients with diabetes are more likely to be hospitalized and experience longer lengths of stay than those without diabetes. In addition, 30 – 40 % of all hospitalized patients develop hyperglycemia, with average hospital stays that are up to three days longer than for patients without hyperglycemia.

The evidence for inpatient glycemic control is substantial. Hyperglycemia in hospitalized patients is strongly linked to poor outcomes regardless of whether or not the patient has a diagnosis of diabetes. Patients with both new hyperglycemia and known diabetes are more likely to require admission to the intensive care unit (ICU) when compared to patients with well controlled blood glucose. For cardiac surgery patients, hyperglycemia is an independent predictor of mortality. Diabetes experts and interprofessional teams are essential components needed to translate evidence based practice for glycemic management into the inpatient setting. The purpose of this evidence based project is to evaluate the effectiveness of a nurse practitioner (NP) led team on achieving glycemic goals for post-cardiac surgery patients.

The project uses the Centers for Medicare and Medicaid Services (CMS) surgical care improvement project (SCIP) glycemic measure to benchmark glycemic goals. Prior to 2014, our institution evaluated glycemic data on postoperative days one and two. The goal was to achieve 6 A.M. blood glucose values of less than 200 mg/dL. Glycemic goals were consistently met at a rate of 96 % or higher. On January 1st, 2014 an additional glycemic measure was added on postoperative day one. The new criteria stipulated that blood glucose must be 180 mg/dL or less, hours 18 through 24 post-anesthesia end-time. The new glycemic goals were met for only 84 percent of patients, revealing a significant need for improvement of glycemic management processes.

Project Objectives

The first project objective is to determine the effectiveness of an NP led team on glycemic management of postoperative cardiac surgery patients. The 2014 SCIP measure defined euglycemia as maintenance of blood glucose of 180 mg/dL or less for hours 18 through 24 post anesthesia end-time. The project goal is to meet this requirement at a threshold of 95.8 percent.

The second project objective is to determine if individualized insulin and nutrition therapy interventions by the NP team will increase the incidence of hypoglycemia in postoperative cardiac surgery patients. Blood glucose results will be monitored for 48 hours following anesthesia end-time and/or discharge, whichever comes first. The project goal is to maintain a zero percent incidence of hypoglycemia.  The measured blood glucose ranges are 0 – 39 mg/dL and 40 to 69 mg/dL.

The third project objective is to evaluate nursing satisfaction with implementation of the performance improvement project. Cardiac surgery nurses may not feel that they were engaged in development and implementation of the performance improvement project. Nursing satisfaction will be rated with a five question anonymous survey, utilizing a five point Likert scale of measure. Achievement will be measured as 80 percent or more nurses rating overall satisfaction with implementing the performance improvement project at a 4 (agree) or 5 (strongly agree) on the Likert scale for a minimum of four questions.


This is a single-center descriptive, prospective, comparative analysis of an NP led quality improvement project. The analysis is designed to assess the effectiveness of NP management of hyperglycemia in post cardiac surgery patients. The measure of success is based on compliance with the 2014 SCIP glycemic requirements for this population. The prospective analysis will not be masked to the investigators or staff. The project is a chart review of postoperative cardiac surgery patients. No subject recruitment or consent is indicated. The analysis will evaluate compliance with the 2014 SCIP glycemic control requirements of blood glucose 180 mg/dL or less between hours 18 and 24 post anesthesia end time. The analysis will evaluate for incidences of hypoglycemia, defined as blood glucose less than 70 mg/dL and for critically low values defined as blood glucose results of less than 40 mg/dL., for the period of 48 hours post anesthesia end time. The analysis will also assess nursing satisfaction with evidence based process changes.

Data Analysis

Data analysis will be carried out using the Statistical Package for Social Sciences (SPSS Inc., Chicago, IL and USA), version 22. Descriptive statistics such as frequency distribution (percentages), measures of central tendency (mean, median), and measures of dispersion (range, standard deviation) will be used to describe the sample population and overall utilization rate. A paired t-test will be used to show the difference between the changes in glycemic management processes and patient outcomes. In this project, statistical significance will be considered when the probability is equal to or less than 0.05. The final analyses will use descriptive statistics and chi-square tests. Secondary aims will be analyzed, using Pearson’s correlation. Analysis is under way and data is pending for this project.