How the Preop Workup Can Affect Postop Results
Dr. Steven Roberts discusses why it is wise for the surgeon to request medical clearance for patients before joint replacement surgery, especially if there are any questions about a patient’s medical condition.
Steven E. Roberts, MD
The preoperative medical evaluation is an important contributor to perioperative and postoperative outcomes in joint arthroplasty patients. Clearing the patient medically is more than simply assessing known medical conditions. Instead, the preoperative workup should include:
- Thorough medical and surgical history
- Determination of patient and surgery-specific risk factors
- Recommendations for postoperative care
- Insight into unforeseen comorbidities
There is some debate as to whether every joint arthroplasty patient needs medical clearance before surgery. An otherwise healthy patient can generally proceed safely to surgery without a preoperative medical workup.
However, obtaining medical clearance may protect the surgeon from any medical-legal issues that arise as a result of surgery, and it may also fulfill hospital and/or anesthesia requirements. In general, it is wise to obtain clearance if the surgeon has any questions about the patient’s medical condition.
Predicting Cardiac Risk
Historically, many attempts have been made to develop guidelines that would predict cardiovascular outcomes among surgery patients.
Goldman’s Criteria,  introduced in the late 1970s, was the first preoperative cardiac risk index with multifactorial predictors. In 1986, Detsky and colleagues  modified the original index by adding variables and predictive information for major and minor surgeries.
The joint effort of the American College of Cardiology and the American Heart Association led to guidelines in 1996 and 2002. [3,4] The 1996 guidelines subjected the patient to unnecessary cardiac testing and was somewhat simplified by the 2002 guidelines.
In 2007, ACC/AHA published new guidelines that further simplified the cardiac risk stratification process.  Essentially, the patient can safely have surgery if he or she does not have active angina, Class IV heart failure, severe cardiac valvular disease, or heart block, and he or she can achieve 4 Metabolic Equivalent of Tasks (4 METs = household work) or unknown METs.
Even patients with a known but stable history of diabetes, heart disease, heart failure, stroke, or kidney disease can safely have surgery with beta blockade. Cardiac testing is only indicated if it will change patient management – for example, if the patient is having worsening symptoms or the testing is due or overdue.
The Impact of Comorbidities
Perioperative complications due to surgery are rarely directly due to orthopedic problems. Most of the complications are due to medical issues; less than 5% are cardiac in nature. In most cases, these issues can be anticipated: It has been shown that 90% of medical complications occur within 4 days of surgery. 
From 1998 to 2008, the age of patients undergoing joint arthroplasty increased, as did the use of skilled nursing on discharge. This led to a decrease in hospital length of stay and in-hospital mortality. Not surprisingly, there also post-discharge increases in:
- Pulmonary embolism
- Pneumonia 
Patients with obstructive sleep apnea, which is rarely mentioned in a preoperative medical clearance, have been shown to have an increased:
- In-hospital mortality
- Pulmonary embolism
- Wound hematoma and seroma
- Medical costs 
Furthermore, metabolic syndrome has been shown to be an independent risk factor for the development of major complications, non-routine discharge, and increased length of stay. 
Obesity, which is a component of metabolic syndrome, also leads to comorbidities in the joint arthroplasty patient. A BMI > 30 has been shown to have a negative effect on outcomes in total knee arthroplasty, with a significantly higher revision rate.  In addition, obese women have been shown to have a higher incidence of infection and dislocation, with lower functional outcomes and satisfaction, when compared with obese men and non-obese women. 
In a landmark study of more than 1 million patients from 1988 to 2005, patients with uncontrolled diabetes had a higher incidence of:
- Urinary tract infection
- Death 
They also needed more transfusions and had a longer length of stay. 
In another study, the rate of infection among patients with diabetes was higher regardless of the hemoglobin A1C level. 
The solution to limiting postoperative morbidities seems simple: obtain medical clearance.
In reality, however, “medical clearance” may not take into account all aspects of the patient’s condition and preoperative and postoperative needs. Often, the patient’s primary care provider will clear the patient but not provide further insight.
Despite ACC/AHA guidelines to the contrary, a cardiologist may perform a preoperative electrocardiogram, 2D echocardiogram, nuclear stress test, and carotid dopplers and still come to the same “patient is cleared for surgery” conclusion.
In all likelihood, neither physician anticipated or mentioned postoperative treatment of comorbidities such as sleep apnea, diabetes, or benign prostatic hyperplasia.
In addition, research has shown poor validity between patient’s actual history and the history reported by the physician, further complicating an adequate preoperative evaluation. One study found substantial agreement between the patient and physician on diabetes and lung disease, but only slight to moderate agreement on other comorbidities. Peripheral vascular disease had no agreement between patient and physician reported histories. 
The optimum approach to achieving post-operative success lies in obtaining a proper and thorough preoperative workup. Co-management with a particular primary care physician or group of physicians has been shown to lead to fewer complications and shorter length of stay. 
In one model,  the preoperative medical workup, in-hospital medical consult, and, if needed, the skilled nursing facility (SNF) admission were done by the same physician.
A co-management approach involving the orthopedic surgeons and the primary care physician  led to specific preoperative treatment programs involving:
- Diabetes and blood pressure control
- Sleep apnea testing and education
- Smoking cessation
- Blood management programs
- Preoperative education classes
- Weight loss programs
- “Tweaking” of hospital and SNF post-op orders
As a result of this collaboration, average length of stay (LOS) was 2.5 days.  This LOS included revision arthroplasty patients, as well as patients requiring SNF upon discharge.
In addition, the use of adult trauma and critical care blood management guidelines  and preoperative erythropoietin when needed resulted in 2 transfusions per year in primary arthroplasty patients and 5 per year in revision arthroplasty patients.
Poorly controlled diabetes mellitus was also treated by the co-management team, leading to successful total joint replacement and improved diabetes control (A1C < 6.5). In one instance, a poorly controlled diabetic treated with this approach had such improved glycemic control that he was able to have a total knee arthroplasty performed in the outpatient setting.
Both mortality and deep infection rate over a 12 month period involving approximately 500 primary joint replacements was 0%.
Pros and Cons of Co-management
The advantages of a co-management approach include more than just detailed, accurate, and faster medical clearances:
- Improved continuity of care
- Increased patient satisfaction
- Less use of packed red blood cells
- Less in-hospital subspecialty care
- Lower costs
- Shorter LOS
- Fewer last minute cancellations
Readmissions and unexpected emergency room patient visits have also been lower due to the availability of a dedicated primary care provider to treat the medical problem in the office setting before the problem escalates. 
The disadvantages to this approach are few. Resistance from both patients and other primary care providers can initially be high. However, these concerns can dwindle after an explanation of purpose and outcomes.
The increasing use of hospitalists and the unavailability of the usual primary care provider have also helped with this transition.
The other main issue with this model is finding a primary care physician who is willing to work in this type of patient-care setting. One option is a family practitioner or internist who also has a certificate of added qualification in sports medicine.
These physicians can work closely with the surgical team and already have a basic knowledge of wound care and orthopedics. Both parties may find the collaborative effort financially  and academically rewarding. According to National Resident Matching Program data, approximately 170 such physicians are enrolling in fellowships each year. 
The current literature is clear regarding the unique medical problems of the joint arthroplasty patient. Algorithm-based cardiology clearance is simple to follow but does not address the other more common medical problems.
A co-managed approach between orthopedics and primary care during the pre- and postoperative period seems to lead to more favorable patient outcomes.
Steven E. Roberts, MD, is Medical Director of STAR Orthopaedics, La Quinta, California.
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