From the Guidelines
Edema should be evaluated through a comprehensive physical examination and patient history, including inspection, pitting test, and measurement of affected limb circumference, as well as consideration of potential causes and laboratory tests or imaging studies as needed. When assessing edema, it is essential to consider the location, extent, and symmetry of the swelling, as well as any associated symptoms such as pain, shortness of breath, or chest pain 1. The pitting test can be used to grade the severity of edema, with a scale of 1+ (mild, 2mm depression) to 4+ (severe, 8mm depression that persists) 1. Potential causes of edema include heart failure, kidney disease, liver problems, venous insufficiency, medication side effects, or local inflammation, and laboratory tests such as comprehensive metabolic panel, complete blood count, urinalysis, and cardiac biomarkers may be necessary to determine the underlying cause 1. Imaging studies like ultrasound, echocardiogram, or CT scans might be indicated for further evaluation, especially if there are signs of heart failure or other systemic conditions 1. It is also crucial to assess arterial perfusion and decide whether and when further vascular assessment or revascularization is needed, particularly in patients with diabetes 1. By taking a systematic approach to evaluating edema, healthcare providers can determine the underlying cause and guide appropriate treatment, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life. Some key points to consider when evaluating edema include:
- Inspecting the affected area for swelling and noting its location, extent, and symmetry
- Performing the pitting test to grade the severity of edema
- Measuring the circumference of affected limbs and comparing with unaffected sides or baseline measurements
- Asking about onset, duration, pain, and associated symptoms
- Considering potential causes, including heart failure, kidney disease, liver problems, venous insufficiency, medication side effects, or local inflammation
- Ordering laboratory tests or imaging studies as needed to determine the underlying cause.
From the Research
Assessment of Edema
To evaluate edema, several methods can be employed, including:
- Measuring the circumference or volume of the affected area 2
- Checking for pitting edema by applying finger pressure to the edematous area 3
- Using validated decision rules, such as the Wells and STOP-Bang criteria, to guide decision-making regarding the possibility of venous thromboembolic disease and obstructive sleep apnea, respectively 4
- Obtaining a basic metabolic panel, liver function tests, thyroid function testing, brain natriuretic peptide levels, and a urine protein/creatinine ratio to guide evaluation 4
- Performing duplex ultrasonography with reflux to diagnose chronic venous insufficiency in patients with chronic bilateral lower-extremity edema 4
- Using ankle circumference and water displacement to quantitatively assess peripheral edema, which have shown excellent reliability 5
Evaluation of Edema Severity
The severity of edema can be evaluated using various methods, including:
- Clinical assessment of pit depth and recovery at three locations 5
- Patient questionnaire to assess the level and frequency of edema 5
- Figure-of-eight (ankle circumference using eight ankle/foot landmarks) 5
- Edema tester (plastic card with holes of varying size pressed to the ankle with a blood pressure cuff) 5
- Modified edema tester (edema tester with bumps) 5
- Indirect leg volume (by series of ankle/leg circumferences) 5
- Foot/ankle volumetry by water displacement 5
Diagnostic Considerations
When evaluating edema, it is essential to consider the underlying cause, which can include: