Why Accurate Insulin Dosing is Critical to Treatment of Wounds

Prior to 1921, little was known about the function of the pancreas, and a diagnosis of diabetes almost invariably led to mortality. As insulin enjoyed wider therapeutic application, patient outcomes dramatically improved, and this was not limited to those with diabetes.

According to an article on the history of insulin by Michael Hrynyk and Ronald Neufeld, “Insulin’s role in wound healing can be traced back to the early 20th century, to surgeons who observed differences in healing rates amongst patients with diabetes and patients without diabetes recovering from surgery. Specifically in patients with diabetes, wounds would fail to re-epithelialize normally, exposing open wounds to the environment, and resulting in risk for infections.

As the infection spread to the blood, death would soon follow. After the discovery of insulin in 1921, insulin was used to treat postoperative (nondiabetic) acidosis. At the time, doctors had been monitoring three patients who had undergone surgery and were suffering from severe vomiting and post-operative metabolic imbalance.

After injecting three patients with glucose and 10 units of insulin, the symptoms of acidosis cleared, and the metabolic balance was restored. The mortality rate from infection in diabetics was reduced from 40 to 12% in those patients receiving insulin therapy intravenously amongst 20 patients.

This research provided early indications of insulin’s ability to improve wound healing and enhance postoperative health in patients with diabetes and patients without diabetes. In the last 30 years, human and animal wound healing studies have been focused on understanding and controlling the intense biochemical and physiological changes that follow post-burn, according to Hrynyk/Neufeld.

The majority of these studies have been directed toward potential clinical approaches and outcomes. From these reports, it is clear that hyperglycemia and insulin resistance are widely observed in severely burned patients, reducing their chances of a successful recovery.

Precise Dosing is Critical for Treatment of Wounds

Dr. Elizabeth Mann-Salinas understands the critical importance of the precise dosing of insulin in the treatment of burns and other wounds.  She is a nurse scientist at the U.S. Army Institute of Surgical Research in San Antonio, Texas, and has researched and written extensively on this subject. In a report published in the Journal of Burn Care & Research, Dr. Mann-Salinas and her colleagues examined how computer decision support software safely improves glycemic control in the burn intensive care unit.

Are there differences between treating burns and other wounds?

“Burn patients are very complex,” Dr. Mann-Salinas noted. “The burn injury causes a significant inflammatory response, making the patient more immune-compromised. The patient is more susceptible to infection, and is hypermetabolic so they are rapidly using all of their stored energy. This is why the anabolic property of insulin is very important.  Basically, these patients don’t have enough nutrients to heal their wounds.”

German Study Shows Effect of Insulin on Wounds

A recent German study outlines the problems patients with diabetes have while wounds are healing. It had previously been assumed that high levels of glucose in the blood damages vessels and neurons and impairs the immune system, thereby accounting for the wound-healing problems. This study suggests that slowed insulin metabolism at the wound site directly affects neighboring cells involved in wound healing.

Dr. Mann-Salinas was asked about the role glycemic control – and the accuracy of dosing – plays in wound healing and preventing infections.

“When there is severe inflammatory response such as sepsis, insulin resistance will occur,” she said. “The cells in a burn patient are unable to absorb glucose and insulin is the vehicle which transports glucose into the cells. If the patient is insulin-resistant, they are unable to get nutrients into their cells. If there is a wound, with potentially viable cells, they are going to starve to death.

“With regard to patients with diabetes, they are unable to utilize insulin,” she noted. “A burn patient is very much like a patient with type 2 diabetes. Their cells are not getting the nutrients they need to live.

“There is also a problem of having too much glucose in the body because bacteria can thrive in that type of environment. The microbes which are floating around the body are very well-fed,” she continued, “and this can lead to systemic infections.”

“This explains why accurate insulin dosing is so critical in these types of cases,” she said. “While burn patients were excluded from the well-known NICE-SUGAR study, trauma patients were included and they were the only group which benefited from increased insulin treatment. I believe we need another study which includes burn patients in order to determine the optimal level of insulin for this cohort.

“In our burn center, we recognized the need for tight glucose control and we purchased EndoTool to help us reach this objective. We did this after we conducted a formal, randomized, cross-over study to prove that it was safe. This resulted in our paper, Computer Decision Support Software Safely Improves Glycemic Control in the Burn Intensive Care Unit: A Randomized Controlled Clinical Study.” This study strongly suggested that if this software works in the challenging environment of a burn center, it can work in any other sector.

“EndoTool is absolutely effective with maintaining glucose control, and we have found that this software recommends higher dosing of insulin than our paper protocol resulting in quicker healing.  In the case of a burn patient, until that wound has healed, that patient is at risk for death,” she concluded.