This article is more than 5 years old. Information may no longer be current.
Glycemia control and infection: Need for prospective studies in orthopedics
Click Here to Manage Email Alerts
According to statistics published by the Centers for Disease Control and Prevention in 2007, 23.6 million people (7.8%) in the United States have diabetes. It is estimated that 5.7 million of these people are unaware of their disease. Among patients 60 years old and older, the incidence is even greater at 23.1%.
Diabetes is a known risk factor for infection following surgery. The “diabetic disadvantage” has been shown across multiple surgical specialties and within multiple orthopedic disciplines. This disadvantage is especially troubling in patients undergoing total joint arthroplasty.
With a large number of undiagnosed patients with diabetes in the United States and a large percentage of joint replacement candidates older than 60 years, the question of whether to screen those undergoing joint arthroplasty is a pertinent one.
Screening could be in the form of a hemoglobin A1C or fasting glucose level taken during routine preoperative blood work. A1C measurements greater than or equal to 6.5% or a fasting glucose greater than or equal to 126 mg/dL would be diagnostic of diabetes. Hemoglobin A1C measurements of less than 7% have been shown to be associated with a significantly decreased risk of postoperative infection among patients with diabetes.
|
|
Decreased immune system function
Hyperglycemia leads to decreased immune system function. It has been shown to decrease leukocyte function at blood sugar levels as low as 200 mg/dL. This dysfunction appears to improve when blood sugar levels are returned to normal. Strict perioperative glycemic control has been shown to be a successful method to decrease the rate of infection. In their study, Furnary and Yu were able to use insulin to achieve strict glycemic control in a group of patients undergoing coronary artery bypass grafting, which normalized deep sternal wound infection rates in patients with diabetes compared with those of nondiabetic patients. This effect was seen even in patients with poor long-term glycemic control, as determined by hemoglobin A1C measurement. To our knowledge, there are no prospective orthopedic studies of this nature.
Stringent control of blood sugar is not without risk. To avoid the dangerous situation of hypoglycemia, one must be careful to avoid overcorrection. The current literature does not provide a clear consensus on the desired target range for serum glucose in order to minimize the risk of infection. An ideal range would be one that decreases the chance of infection, while minimizing the possibility of hypoglycemia.
A few studies indicate postoperative glucose less than 200 mg/dL to be a risk factor for infection, while others have shown decreased infection rates with postoperative blood glucose levels less than 175 mg/dL. From the literature, it is safe to say that blood glucose less than 200 mg/dL is desired, while aiming for levels lower than 120 mg/dL could potentially be detrimental to outcomes.
Need for prospective studies
While it has been thoroughly documented in the orthopedic literature that diabetes is a risk factor for infection and adverse outcomes following total joint arthroplasty, minimal research has been conducted into improving these outcomes. Some work in other surgical disciplines has shown much promise with strict perioperative glucose control.
There is a need for prospective studies attempting to replicate these results in the orthopedic population. These studies should also look into the ideal serum glucose range – maximizing infection prevention while minimizing hypoglycemia. If we can improve outcomes of patients diagnosed with diabetes, it is reasonable to consider screening the general population. This is an area of orthopedics that is largely unstudied and holds much promise in improving our patient outcomes.
References:
- Dronge AS, Perkal MF, Kancir S, et al. Long-term glycemic control and postoperative infectious complications. Arch Surg. 2006;141:375-380.
- Furnary AP, Wu Y. Eliminating the diabetic disadvantage: the Portland Diabetic Project. Semin Thorac Cardiovasc Surg. 2006 Winter;18:302-308.
- Gupta S, Koirala J, Khardori R, Khardori N. Infections in diabetes mellitus and hyperglycemia. Infect Dis Clin North Am. 2007;21:617-638.
- MacRury SM, Gemmell CG, Paterson KR, MacCuish AC. Changes in phagocytic function with glycaemic control in diabetic patients. J Clin Pathol. 1989;42:1143-1147.
- National Diabetes Fact Sheet, 2007. http://apps.nccd.cdc.gov/DDTSTRS/FactSheet.aspx. Accessed April 19, 2011.
- Javad Parvizi, MD, FRCS, editor of Infection Watch, can be reached at the Rothman Institute, 925 Chestnut St., 5th Floor, Philadelphia, PA 19107; 267-339-3617; email: parvj@aol.com.
- Disclosures: Parvizi is a consultant to Stryker. McCoy has no relevant financial disclosures.
