natriuretic-peptide--brain and Lymphedema

Edema is a common clinical sign that may indicate numerous pathologies. As a sequela of imbalanced capillary hemodynamics, edema is an accumulation of fluid in the interstitial compartment. The chronicity and laterality of the edema guide evaluation. Medications (e.g., antihypertensives, anti-inflammatory drugs, hormones) can contribute to edema. Evaluation should begin with obtaining a basic metabolic panel, liver function tests, thyroid function testing, brain natriuretic peptide levels, and a urine protein/creatinine ratio. Validated decision rules, such as the Wells and STOP-Bang (snoring, tired, observed, pressure, body mass index, age, neck size, gender) criteria, can guide decision-making regarding the possibility of venous thromboembolic disease and obstructive sleep apnea, respectively. Acute unilateral lower-extremity edema warrants immediate evaluation for deep venous thrombosis with a d-dimer test or compression ultrasonography. For patients with chronic bilateral lower-extremity edema, duplex ultrasonography with reflux can help diagnose chronic venous insufficiency. Patients with pulmonary edema or elevated brain natriuretic peptide levels should undergo echocardiography to assess for heart failure. Lymphedema is often a clinical diagnosis; lymphoscintigraphy can be performed if the diagnosis is unclear. Treatment of edema is specific to the etiology. Diuretics are effective but should be used only for systemic causes of edema. Ruscus extract and horse chestnut seed demonstrate moderate-quality evidence to improve edema from chronic venous insufficiency. Compression therapy is effective for most causes of edema.

Topics: Edema; Humans; Lymphedema; Natriuretic Peptide, Brain; Primary Health Care; Venous Insufficiency

Lymphedema often responds to compression therapy which can also cause undesirable cardiac overload if heart failure coexists. We hypothesized that the biomarker B-type natriuretic peptide (BNP) can be used to screen lymphedema patients for undetected cardiac dysfunction. We studied unselected consecutive patients with lymphedema to determine their BNP status and compared these data with those obtained from healthy subjects without known cardiovascular diseases. Out of a total of 305 subjects with lymphedema screened, 102 (33%) consented to take part in this study. The majority (87%) were female with a mean age of 60.5 +/- 13.2 (SD) years, and 47% had just lower limb swelling. The groups were equally divided between cancer and non-cancer related causes. There were 45 females and 4 males under 60 years old, and 44 female and 9 male patients over 60 years old. Median (IQR) BNP (ng/L) were as follows: <60 years females = 17.9 (15.2) (median [RR: 3 - 64] and males = 12.4 (14.7) [RR: 0.2 - 44], >60 years females = 35.8 (57.9) [RR: 2 -247)] and males = 47.2 (44.1) [RR: 2 - 238]. For this population, the BNP concentration 100 ng/L was adopted as the value to exclude heart failure. Using this definition, 7 lymphedema subjects had BNP concentrations of 120 (19.8) ng/L, and all were found to have cardiac abnormalities on echocardiography. This study demonstrated that 93% of unselected subjects with lymphedema had BNP concentrations that exclude a diagnosis of heart failure. Those subjects with elevated BNP were found on subsequent echocardiography to have cardiac abnormalities. The use of a BNP assay is of potential value in screening patients who are more likely to have cardiac failure. Indicative factors include bilateral leg swelling, over the age of 50 years, breathlessness, where there is no known cause for the swelling. A BNP assay using a BNP concentration threshold of 100 ng/L (29 pmol/L) will identify those patients who require more detailed investigations.

Topics: Adult; Biomarkers; Female; Heart Failure; Humans; Lymphedema; Male; Middle Aged; Natriuretic Peptide, Brain