In collaboration with QxMD contributor Dr. Sang Woo we have just released the Woo Perioperative Risk Calculator (https://qxmd.com/calculate/calculator_823). Based on the recently released paper from Dr. Woo (https://read.qxmd.com/read/33522252). We are really excited about this tool and think it will be very useful for a lot of clinicians. We asked Dr. Woo a few questions to give you more insight into the calculator.
What motivated you to develop the tool?
I felt that there was an important unmet need in perioperative stroke risk assessment. I realized this when my patient developed a major stroke after hip fracture surgery even though the patient underwent the usual preoperative cardiac evaluation and clearance. The risk of stroke was not assessed during our preoperative evaluation as preop risk calculators that our clinician used (such as RCRI, Gupta MICA or ACS surgical risk calculator) do not assess the risk of stroke.
Do you have any tips for ways to integrate the tool into regular clinical practice?
When I see patients for preoperative evaluation, I often use more than one risk calculator and compare the results of each calculator for high risk patients. I would suggest considering using this calculator when clinicians use other risk calculators like RCRI, Gupta MICA or ACS surgical risk calculator. Each calculator has its strength and weakness, so it would be useful to compare results which might provide additional information.
How do you normally share the results with the patient? Do you always include the risk of mortality?
Patients with chronic medical conditions often ask questions like “Am I going to survive after this surgery?”. We need to inform patients of mortality risk in order to answer questions like this. Just addressing cardiac risk is not enough as these patients may be at risk of other major complications like stroke, kidney failure, thromboembolism and sepsis leading to mortality. I think that discussing the risk of mortality is important in helping our patients to make informed decisions about their surgery.
Are there any types of surgery, in particular, where you think it is very important to use the tool?
The use of this risk calculator is not limited to high risk surgery types, but there are surgery types that are particularly high risk for stroke and mortality. Vascular surgery, intra-abdominal and thoracic surgery are those examples. We included subtypes of vascular surgery such as carotid endarterectomy, aorta, supra-inguinal, and infra-inguinal surgery. We also made separate categories of open aorta surgery and endovascular aneurysm repair as the surgical risks are quite different among these vascular surgery subtypes. I would be careful about calling certain surgery types low risk, as these surgeries can also be high risk if patients have comorbid conditions like previous stroke or coronary artery disease.
Are there any additional factors clinicians should be aware of that aren’t included in the tool algorithm?
We need to remember that our risk model and other statistical models have limits and should be used just as a tool that helps our clinicians in their clinical assessment. I believe that clinicians’ experience, careful history taking and examination are most important in accurate preoperative risk assessment and management.
How can clinicians utilize the risk of perioperative stroke in patient counseling about risk?
When clinicians identify patients at high stroke risk using this calculator, they can discuss the perioperative management strategies with their patients to lower stroke risk. A recent scientific statement from the American Heart Association/American Stroke Association (https://read.qxmd.com/read/33827230) summarized preoperative and perioperative strategies to lower stroke risk. This is a very good and comprehensive summary and I highly recommend clinicians to read this paper. Clinicians can also recommend patients the ideal timing of surgery if they have a history of stroke. Even though stroke risk is highest during the first 48 hours after surgery, about 25% of strokes occurred after patients were discharged from hospitals in our study. Providing patients the education about stroke symptoms such as F.A.S.T warning signs may help reduce morbidity and mortality of perioperative stroke.
