SLR - October 2012 - Caitlin Garwood
Reference: Richards, JE, Rondi M. Kauffmann, Scott L. Zuckerman, William T. Obremskey, & Addison K. May. Relationship of Hyperglycemia and Surgical-Site Infection in Orthopaedic Surgery, Journal of Bone and Joint Surgery. 2012 July; 94-A(13): 1181-1186
Scientific Literature Review
Reviewed by: Caitlin Garwood, DPM
Residency Program: Inova Fairfax Hospital, Falls Church, VA
Podiatric Relevance:
Almost one-third of patients admitted to the hospital without a history of diabetes have an incident of hyperglycemia. Stress-induced hyperglycemic response after a traumatic injury has been correlated with a poorer outcome. The authors studied the relationship between hyperglycemia during admission for an isolated orthopaedic injury needing acute surgical intervention and the rate of thirty-day postoperative surgical site infection in patients with no history of diabetes.
Methods:
Between January 2004 and October 2009 all patients admitted with an isolated orthopaedic injury requiring acute operative management were identified at a level I trauma center. Inclusion criteria was an age of eighteen or older, an isolated orthopaedic injury in need of acute operative management, and an extremity Abbreviated Injury Scale (AIS) score of two. Patients were excluded for history of diabetes, an AIS score in a body region other than an extremity, history of corticosteroid use, or ICU admission.
Blood glucose values were gathered from the basic metabolic profiles or fingerstick glucose measurements recorded on the charts. Hyperglycemia was defined as two random glucose values 200 mg/dL or hyperglycemic index of 1.76 (equal to 140mg/dL). Hyperglycemic index was measured by the area under the curve of all glucose values over the entire hospital stay, requiring at least two blood glucose values and excluding all values obtained after diagnosis of infection. A thirty-day postoperative surgical site infection was identified by diagnosis codes for postoperative infection and wound dehiscence. Only those cases that required reoperation for the infection were classified as a primary outcome.
Results:
Seven hundred and ninety patients met all the inclusion criteria and had at least two blood glucose values. Injuries included 147 upper-extremity injuries, 144 pelvic or acetabular fractures, 281 femur fractures, 167 tibial fractures, and 51 foot injuries. Open fractures consisted of 33.9 percent of the population cohort. There were 21 (2.7 percent) surgical-site infections with a mean time to identification of 20.1 days. Age, race, comorbidities, injury severity, and blood transfusion were not associated with the primary outcome. Thirteen (4.4 percent) of 294 patients with two or more blood glucose values 200mg/dL versus eight (1.6 percent) of patients without hyperglycemia by this definition had a surgical-site infection. Similarly, surgical-site infection was seen in ten (7.5 percent) of 134 patients with hyperglycemic index 1.76 versus eleven (1.7 percent) of 656 patients without this hyperglycemic index. With an adjustment for open fractures, both blood glucose 200mg/dL and hyperglycemic index 1.76 were independent risk factors for thirty-day surgical site infection.
Conclusions:
The results of this study demonstrate that hyperglycemia following musculoskeletal injury is not a benign phenomenon and can have substantial effect on post-operative management. By either definition, hyperglycemia was shown to be an independent risk factor for thirty-day surgical site infections in orthopaedic trauma patients without diabetes.