This post is intended primarily for therapists to serve as a resource, giving insight into how lab values can be helpful.
A person may be referred for lymphedema treatment but have a mixed condition of lymphedema plus another diagnosis (for example, Congestive Heart Failure or Renal Dysfunction). How is treatment affecting them? Sometimes a patient may be referred but not be appropriate for treatment. Besides your medical history & assessment, lab values can provide you with confirmation of why you shouldn’t be seeing them or how your treatment is affecting them. Consider these scenarios:
Scenario 1 – A patient is in the hospital & is referred for lymphedema treatment. You notice they have a diagnosis of congestive heart failure. Should you treat them? If heart failure is the underlying cause of swelling, we know the answer is no; once the condition is medically managed, their swelling will reduce. But what if heart failure is co-existing with another component causing lymphedema?
Scenario 2 – How about a person with lymphedema who has one kidney? You might have concerns moving fluid may overwhelm their renal function & induce renal failure. What resource can you use to monitor a patient’s tolerance?
Scenario 3 – A person presents with soft, symmetrical, bilateral leg swelling that includes the thighs & abdomen. That in itself is a warning sign but what else might you use to determine the underlying cause & give reason for not treating them?
The answer to these questions lies in the use of lab values. These are especially helpful in an acute care setting but they may beneficial in other settings as well. If you have lab values as a reference, when reviewing them ask, “Are these values high, low or normal?” “Are they trending up or down?” Use the pattern seen the past couple of days to determine not only if they are stable enough to tolerate treatment but to monitor how they are tolerating treatment once it has begun. If the answer indicates a decline in function, treatment should be delayed & the patient re-assessed later for appropriateness.
Some of the most common & helpful lab values include:
Brain Natriuretic Peptide (BNP) – A hormone secreted by the heart as a result of volume overload. Range: >100 pg/dL indicates heart failure is present.
Blood Urea & Nitrogen (BUN) – Urea & nitrogen are formed in the liver due to breakdown of dietary protein which is excreted in urine. BUN measures liver metabolic function & the excretory function of the kidneys. Range: >20 mg/dL can indicate congestive heart failure or myocardial infarct. <6 mg/dL can indicate malnutrition & liver failure.
Creatinine – A by-product of muscle metabolism & an indicator of renal function. Range: >1.3 mg/dL may be a result of renal dysfunction or congestive heart failure.
Albumin (ALB) & Prealbumin (PAB) – Albumin is the primary protein for maintaining colloid osmotic pressure in the vascular & extravascular spaces. It prevents fluid from leaking into the interstitium. Low levels of albumin leads to peripheral edema &, potentially, hypotension. It is often used as an indicator of malnutrition as it is a more readily available test. However, it has a 21-day half-life & is slower to respond to nutritional changes. Prealbumin is the better indicator of nutritional status because it changes more quickly. Albumin Range: < 3.5 g/dL can indicate infection, inflammation & malnutrition. Prealbumin Range: < 19 indicates malnutrition.
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Malone, D., & Lindsay, K. (2006). Physical Therapy in Acute Care. Thorofare, NJ: SLACK Incorporated.