What is the recommended approach for conducting a functional risk assessment in a patient prior to a medical procedure?

Functional Risk Assessment Prior to Medical Procedures

Assess functional capacity using a structured, stepwise approach beginning with gait speed screening (5-meter walk test with 3 trials), followed by validated questionnaires (Duke Activity Status Index) or standardized questions about ability to climb 2 flights of stairs, and reserve cardiopulmonary exercise testing for elevated-risk patients with unknown functional capacity where results will change management. 1

Initial Screening: Gait Speed and Basic Functional Assessment

• Screen all patients with a 5-meter gait speed test (3 timed trials) to rapidly identify frailty risk: patients with gait speed >0.83 m/s with preserved cognition and independence are likely not frail, while those with gait speed <0.5 m/s or <0.83 m/s with disability require further evaluation 1

• Assess independence in activities of daily living (feeding, bathing, dressing, transferring, toileting) as dependent functional status significantly increases perioperative morbidity and mortality 1

• Evaluate cognitive function using Mini Mental State Examination with scores <24 indicating abnormal cognition that may impact surgical decision-making 1

Structured Functional Capacity Assessment

• Use the Duke Activity Status Index (DASI) or standardized questions about ability to climb 2 flights of stairs or walk 4 blocks, as these structured approaches predict moderate-to-severe complications while unstructured patient interviews do not 1, 2

• Classify functional capacity in metabolic equivalents (METs): excellent (>10 METs), good (7-10 METs), moderate (4-6 METs), poor (<4 METs), or unknown, with inability to achieve 4 METs indicating increased perioperative risk 1

• For patients with elevated risk and excellent functional capacity (>10 METs), proceed directly to surgery without further cardiac testing as prognosis is excellent even with stable coronary disease 1

Performance-Based Testing for Elevated-Risk Patients

• Perform 6-minute walk test to assess physical functioning and endurance, as this provides predictive information on likely benefit, long-term mortality, and functional outcomes, ideally in an outpatient setting 1

• Consider cardiopulmonary exercise testing (CPET) for elevated-risk procedures in patients with unknown functional capacity where results will change management, as CPET has the most consistent association with complication risks 1, 2, 3

• Use additional performance assessments including "Up and Go" test, chair stands, or incremental shuttle walk test when CPET is not available, though these require further validation 1, 2

Frailty and Disability Assessment

• Apply validated frailty scales including the Rockwood Frailty Index, Cardiovascular Health Study Frailty Scale, or Edmonton Frail Scale to classify patients as not frail, prefrail, or frail with varying severity 1

• Assess nutritional status using body mass index (<21 kg/m² indicates deficiency), albumin (<3.5 g/dL), Mini Nutritional Assessment (score ≤11 indicates malnutrition risk), or recent weight loss (>10 lb decline in 1 year) 1

• Screen for depression using Center for Epidemiologic Studies Depression Scale as depression confounds cognitive performance and affects functional assessment 1

Risk Stratification Integration

• Combine functional assessment with clinical risk scores: use the Revised Cardiac Risk Index (RCRI) alongside functional capacity, with patients having RCRI 0-1 and good functional capacity proceeding without additional testing 1, 4

• For patients with RCRI ≥2 or poor functional capacity (<4 METs), consider pharmacological stress testing (dobutamine stress echocardiography or myocardial perfusion imaging) if results will change management 1, 4

• Calculate predicted postoperative pulmonary function for thoracic surgery candidates using FEV1 and DLCO with quantitative perfusion scanning, proceeding if both predicted postoperative values exceed 60% 1

Futility Assessment

• Avoid intervention in patients with life expectancy <1 year despite successful procedure or those with <25% chance of "survival with benefit" at 2 years, defined as improvement by at least 1 NYHA functional class, 1 CCS angina class, quality of life improvement, or life expectancy improvement 1

• Engage palliative care specialists when procedures are deemed futile to prevent feelings of abandonment in patients, families, or caregivers 1

Common Pitfalls to Avoid

• Do not rely on unstructured patient interviews for functional capacity assessment as they do not predict outcomes; always use validated questionnaires or standardized questions 2

• Avoid routine testing in low-risk surgery patients (<1% MACE risk) including superficial procedures, cataract surgery, and endoscopic procedures, as testing does not improve outcomes 1, 5

• Do not perform functional testing in inpatient settings when possible, as results may differ significantly from outpatient assessments 1

• Recognize that STS risk scores have limitations in elderly patients as they do not include frailty, disability, or procedure-specific impediments 1

• Ensure testing only when results will change management: additional cardiac imaging should be reserved for patients where test results would influence treatment decisions 1