Hemoglobin A1c
Dr. Mutch went on to discuss hemoglobin A1c (HbA1c) levels as a risk factor in colorectal surgery. HbA1c levels higher than 6 are associated with worse outcomes, but tight postoperative control is associated with hypoglycemia. “What you want to do is set that patient up before surgery. HbA1c has a half-life of about a month, so if you start modifying their risk factors 4-6 weeks before you get them into surgery, by 1 month you can see a 50% reduction, and at 2 months a 75% reduction. If you do these things in a preoperative setting it makes a difference,” said Dr. Mutch.
Smoking cessation
Smoking cessation is another key strategy. Two weeks of cessation should lead to a decline in coughing, but a minimum of 4 weeks is needed to significantly reduce overall complications. Lifestyle changes need to be long term. “These are not measures that you’re going to do over a short period of time, and then when surgery is over throw it out the window,” said Dr. Mutch.
Anastomotic leak
Another factor is the detection of anastomotic leak, which can be challenging because its definitions vary significantly, and its causes can be multifactorial. Studies show that predictions of anastomotic leak are not especially successful, Dr. Mutch said, but routine leak testing improves outcomes. In a study of left-side anastomoses in Washington State, hospitals that performed leak tests had lower leak rates at least 90% of the time (OR, 0.23), and hospitals that later implemented leak tests experienced a significant reduction (Arch Surg. 2012:147[4]:345-51).
Venous thromboembolic events
Venous thromboembolic events (VTE), are the leading cause of operative mortality in colorectal surgery patients. This complication can be greatly reduced with prophylaxis, but requires screening for risk factors. Major surgery raises the risk of deep vein thrombosis in 20% of all hospitalized patients to 40%-80%, depending on the surgery type. “We have a lot of room to improve,” said Dr. Mutch.