After hospitalization for hernia surgery two months ago, my blood sugar levels, which had been reasonably good before I went under the knife, suddenly went haywire. Readings of 200+ mg/dl were common for a couple of days after surgery. My doctors said they were looking at a target of around 180 mg/dl, which they said was optimal. Still, I was unhappy that my A1c levels were compromised.
So it was with interest that I read the new guidelines released by the American College of Physicians recommending that doctors not attempt intensive insulin therapy designed to achieve normal blood sugar levels in patients in medical or surgical intensive care units. These guidelines are for both people with diabetes and without the condition.
The college recommends that doctors should maintain blood sugar levels between 140 and 200 milligrams per deciliter (mg/dl) for anyone in medical or surgical intensive care.
These recommendations ‒ published in the February 15 issue of Annals of Internal Medicine ‒ are similar to the guidelines from the American Diabetes Association (ADA) and the American Association of Clinical Endocrinologists (AACE). However, those guidelines recommend that blood sugar levels should be kept below 180 mg/dl to reduce the risk of infection and other complications.
For reference, in a healthy person with type 2 diabetes, normal blood sugar levels would be between 70 mg/dl and 130 mg/dl before eating. And, even after eating (postprandial), the recommendation from the ADA is to keep blood sugar levels under 180 mg/dl.
Talking to Serena Gordon of Health.com Dr. Amir Qaseem, director of clinical policy in the medical education division of the American College of Physicians explained, “[High blood sugar] is a common finding in hospitalized patients, and it’s associated with a lot of complications, like delayed healing, increased infection, cardiovascular events, you name it. The prevailing thought in the past was that tightly controlling the blood sugar levels would reduce inflammation, clotting and other problems. But, there are also harms that are associated with lowering the blood glucose levels too much. [Low blood sugar] can be very dangerous.”
“The evidence isn’t clear on what range of blood sugar is best, but 140 to 200 mg/dl seems to minimize the risk of hypoglycemia [in surgical or medical units],” said Qaseem. “We felt it was better to stick with a range that is a little bit higher.”
The American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA) have also published updated guidelines for treating high blood glucose while avoiding low blood glucose in hospitalized patients.
The main objectives of the 2009 AACE/ADA recommendations were to identify reasonable, achievable, and safe glycemic targets and to describe the protocols, procedures, and system improvements needed to facilitate their implementation. For most patients a blood glucose target of 140-180 mg/dl is recommended and appropriate use of insulin is the preferred approach for achieving safe, optimal glucose control.
“Hyperglycemia in hospitalized patients is common and associated with increased risk of infection, mortality, and increased cost,” said AACE President Daniel Einhorn, MD, FACP, FACE. “Although near normalization of glucose in these patients appears to be of no greater benefit than moderate glycemic targets, ignoring hyperglycemia in this population is no longer acceptable.”
There is substantial observational evidence linking hyperglycemia in hospitalized patients (with or without diabetes) to poor outcomes. Although initial small studies suggested that intensive glycemic control (insulin infusion with goal blood glucose targets of 80-110 mg/dl) improved outcomes in surgical ICU and medical ICU patients, subsequent trials have failed to show a benefit or have even shown increased mortality of intensive targets compared to more moderate targets (140-180 mg/dl). Moreover, these recent studies have highlighted the risk of severe hypoglycemia resulting from attempts to completely normalize blood glucose.
“Both over treatment and under treatment of hyperglycemia in hospitalized patients are patient safety issues,” said Robert R. Henry, MD, President, Medicine and Science for the American Diabetes Association. “Coordinated, interdisciplinary teams have been shown to achieve both safe and effective control of hyperglycemia in hospitalized patients.”
The recent ACP guidelines are for the most part consistent with the AACE/ADA recommendations. AACE/ADA maintains that the upper limit of 180 mg/dl is safe and justified by data on benefits of glycemic control and the harms of uncontrolled hyperglycemia. Practitioners should take heart in the commonality of recommendations among all the organizations to address hospital hyperglycemia in the safest manner.
Dr. Mary Korytowski, a professor of medicine at the University of Pittsburgh School of Medicine, and a member of the board of directors of the American Diabetes Association, concurs that intensive insulin management in medical and surgical units isn’t the best way to manage blood sugar any more. “(But) 200 mg/dl is probably too high. The 2009 ADA/AACE guidelines recommend 180 mg/dl, which is consistent with postprandial numbers in diabetes care. The problem is that if you set the target too high, those numbers may be even higher when someone starts giving insulin to bring those numbers down,” she explains.
“These guidelines should not be interpreted to mean that glucose control isn’t important for critically ill patients: It is. And it’s important not to let the blood sugar get too high because of the risk of complications, like a higher risk of infection and fluid and electrolyte abnormalities,” she says, adding that it’s important to remember these guidelines give a range of options. “Managing blood sugar closer to the lower end is probably better,” she concludes.
Also see how illness can affect blood sugar levels in people with diabetes from the American Diabetes Association.