Effective Glucose Management in Therapeutic Hypothermia Can Save Patient Neurological Function

Inducing mild hypothermia in some patients with cardiac arrest and other traumatic events has proven to significantly improve their long-term neurological function. Many experts feel that this is one of the most important advancements in the history of the science of resuscitation. According to Dr. Jonathan Adler, writing in Medscape, patients who have been shown to benefit from induced hypothermia include the following:

• Intubated patients with treatment initiated within 6 hours after cardiac arrest.
• Patients able to maintain a systolic blood pressure >90 mm Hg after CPR.
• Patients in a coma at the time of cooling.

When this therapy is used in critical care or the operating room, glucose management is critical to its efficacy, a fact that is appreciated by Tracey Melhuish, Clinical Practice Specialist Critical Care and Sepsis Coordinator and the person responsible for critical care at the 571-bed Holy Cross Hospital in Florida. In response to the challenges of using induced hypothermia as a critical therapy, Ms. Melhuish chose to use EndoTool, a glucose management software for these vulnerable patients.

Reducing Irreparable Neurological Damage

“Prior to using induced hypothermia as a mode of therapy for patients experiencing cardiac arrest, there was little we could do to avoid anoxia – damage to the brain due to a lack of oxygen,” Melhuish noted. “With these patients they would never recover neurologically. The challenge was not only the lack of oxygen, but a cascading series of events. Inducing hypothermia stopped this and allowed the patient to avoid cellular death.”

Why Glycemic Control is Important to the Success of Hypothermia

After cardiac arrest, hyperglycemia is a risk and coupled with therapeutic hypothermia, dangerous blood glucose variability can result. Inducing hypothermia causes a decrease in insulin sensitivity and insulin secretion, which can lead to hyperglycemia.¹

“Insulin is very resistant at the cellular level during hypothermic therapy,” said Melhuish. “Glucose can also cause more swelling, paralyzing the cells and leading to patient mortality. We knew we needed some kind of glycemic control. In the beginning, we had a paper protocol but this was frustrating to everyone because we would ‘max’ it quickly and the glucose would yo-yo all over the place! This is what encouraged us to seek out a non-linear glucose management system. In side-by-side comparisons of the other glucose management tools, we choose EndoTool for intravenous insulin dosing, and we saw the benefits almost immediately. Now, all of our patients are monitored by this software.”

When the process to rewarm a patient is initiated, there is an increased risk of hypoglycemia and insulin sensitivity begins to increase. Therefore, it is critical that this glucose level is stabilized during this process. Melhuish explained how EndoTool anticipates this condition: “As the patient is warmed, the algorithm will predict the insulin fluctuations. This will ensure that the patient’s level will not jump from one extreme to another.”

The Software is Still Performing

In a study, Linking Hypothermia and Hyperglycemia, written in 2009, Melhuish shared her hospital’s experience with the EndoTool software. When asked if the system continues to meet her rigorous standards today, she didn’t hesitate in her response:

“We are extremely pleased with this tool,” she said. “Our hospital is one of the best in the United States and we have built our reputation on evidence-based medicine. We have seen very little incidence of hypoglycemia with our cardiac arrest patients who have been treated with therapeutic hypothermia.”

Reference:

1. Linking hypothermia and hyperglycemia. Nursing Management. 2009 Dec;40(12):42-5.