Article: Importance of Perioperative Glycemic Control in General Surgery. Steve Kwon, MD, MPH, Rachel Thompson, MD, Patchen Dellinger, MD, David Yanez, PhD, Ellen Farrohki, MD, and David Flum, MD, MPH.
Ann Surg 2013; 257: 8-14.
Summary: The group from the University of Washington has done a remarkable job analyzing an area of current controversy by utilizing outcomes in the Washington State’s Surgical Care and Outcomes Assessment Program (SCOAP). The paper utilizes this prospectively collected clinical care benchmarking and quality improvement database to answer the question of whether or not post-operative hyperglycemia impacts the outcome of patients undergoing colorectal or bariatric surgery at nearly all of the centers (47 of 55) in Washington at which these procedures are performed. Although the impact of hyperglycemia has been observed in cardiac, transplant, trauma, vascular, neurosurgical, and ICU patients, it has never been examined in this general surgical patient population.
The SCOAP database was examined retrospectively and the highest blood sugars on POD 0, POD 1, and POD 2 were analyzed and hyperglycemia was defined as glucose levels above 180 mg/dL. The primary outcome assessed was infection and secondary outcomes included in-hospital mortality, reoperation, interventions, length of stay, and myocardial infarction. Logistic regression models were created to evaluate the association between hyperglycemia and outcomes.
The authors were able to demonstrate that hyperglycemia at any post-operative time correlates with an increased mortality and morbidity (reoperation, anastomotic failure, infection, myocardial infarction). Furthermore, these patients experienced a longer length of stay and were less likely to be discharged from the hospital to home. Examining increasing blood sugars by deciles, the authors noted that the risk of infection increased by seven percent for every 10 mg/dL increase in blood glucose.
There are many strengths to the methodology presented by the authors; the greatest being that it is an examination of multiple institutions across the State of Washington utilizing a well-validated database. However, as the authors acknowledge, this is not a prospective, randomized controlled trial and the results should be corroborated by a well-structured multi-institutional trial. Furthermore, although the database utilized is thorough, only one blood glucose is noted daily, the incidence of hypoglycemia is not captured, and the administration of insulin is not examined after the immediate post-operative period.
This study corroborates the results found in many other patient populations that demonstrate that episodes of hyperglycemia are detrimental to the overall outcome of patients undergoing surgery. However, the question as to whether high glucose levels are a marker of severity of disease and poor outcome or a causal factor in worsening of a patient’s post-operative condition remains to be answered.
1) Would the employment of a tight glucose parameter during the operative and post-operative period affect outcome in patients undergoing colon and bariatric surgery?
2) Are there factors other than blood sugar that may affect the incidence of post-operative complications in patients undergoing colon and bariatric surgery?
3) Should blood sugar evaluation become a Surgical Quality Improvement Project measure? For colorectal and bariatric surgery or for all surgical procedures?