Post-operative hyperglycemia and its association with surgical site infection after instrumented spinal fusion

To evaluate the correlation between postoperative hyperglycemia and surgical site infection among patients who underwent primary instrumented spinal fusion surgery.

We collected data on all eligible patients treated at our institution over the course of 2005-2017. We defined serum hyperglycemia using a primary threshold of serum glucose ≥140 mg/dL and used ≥115 mg/dL as a secondary test. We used logistic regression techniques to evaluate unadjusted results for serum hyperglycemia on revision surgeries for infection, followed by sequential adjustment for sociodemographic and procedural characteristics.

We included 3664 patients. Surgical site infections occurred in 4%. Post-operative hyperglycemia was significantly associated with a higher rate of revision surgery for infection (p = 0.02). Following adjusted analysis, hyperglycemia remained a statistically significant predictor for revision surgery due to infection (OR 2.19; 95 % CI 1.13, 4.25). Similar results were evident when using the lower threshold of ≥115 mg/dL (OR 2.36; 95 % CI 1.06, 5.23).

This study highlights the importance of measuring serum glucose after spinal fusion and the need for heightened surveillance and/or treatment in those who exhibit postoperative hyperglycemia. In this context, it could be advantageous to use a lower threshold for hyperglycemia (115 mg/dL) in order to trigger interventions for glycemic control.