I’m Not Sure What to Believe Anymore!

Ever since I was very young, I was taught that there are things that are true and things that are not. It would be up to me to study hard, listen to authoritative people, and find the truth about any subject. Up until recently, the truth was not that hard to find, because there were people and places that could provide anyone with what was considered the truth about a subject. Today, though, it seems that truth is subjective and everyone has his or her own truth; however, that is not what this editorial is about. 

In medicine, we are given information we are told is true based on clinical practice, research, and clinical trials. Unfortunately, even information provided to us by our gold standard, randomized controlled trials, is not infallible. We were told patients with dementia who are not eating and drinking benefit from a feeding tube of some type; that information proved to be false.¹ For years, we have been told eating eggs can be harmful because of the excess cholesterol resulting in a higher incidence of heart disease; apparently, that also is not exactly true. A recent study² compared individuals with type 2 diabetes mellitus who ate fewer eggs to those who ate more eggs and found there was no increase in adverse cardiac events in those who ate the most eggs. This even proved true for those without diabetes.³ What are we to believe now – do we eat eggs or not?

Recently, it was reported⁴ that older adults should not take aspirin, not even low-dose aspirin! We have been told for years that we should all be taking a “baby aspirin” so that we can reduce our chance of cardiovascular problems. Now, it has been discovered that taking aspirin could result in major bleeding and is no longer recommended.⁴ Considering the source, it must be true!

The revision most important to wound care practitioners deals with the Starling principle of microvascular fluid exchange.⁵ We were all taught that because of pressures in the arterial end of the capillary bed, fluid leaks out of the vessels. Different pressures in the venous end of the capillary bed resulted in the majority of the fluid being resorbed into the circulation. A relatively small amount of the fluid and proteins were left in the interstitial space to be removed by the lymphatics – sounded reasonable to me! Unfortunately, more recent and accurate results⁶ have shown very little fluid is resorbed into the venous end of the capillaries, and the majority of the interstitial fluid volume is returned to the circulation through the lymphatics, up to 8 L daily. Any damage to the lymphatics results in significant swelling of the extremity.

This revision⁶ pinpoints several things of clinical importance. First, it shows lymphedema and edema (swelling of the extremity) are not 2 separate problems; if the lymphatics are not intact, swelling will occur. Second, the inflammatory cytokines and other factors residing in the interstitial tissue damage the lymphatics and, over time, result in the clinical picture of lymphedema. Third, since the lymphatics are a low-pressure system, lower compression pressures and light-touch manual lymphatic drainage massage techniques should be useful in treating the early stages of edema and not left until a clinical lymphedematous extremity is present. Fourth, we need to focus on lymphedema as a disease and its treatment. We do not need to ignore it as we so often do. Last, we should work toward treatments that will preserve the lymphatics and improve the damaged extremities in these patients who, at the moment, have very few options regarding successful treatment.

Finding out that what we once thought true is in reality false can be disappointing, but it can lead us down paths to new discoveries and better therapies for our patients.

Terry Treadwell, MD, FACS
woundseditor@hmpglobal.com