You can’t be a clinician and nothave any patient with swollenankles. We often managepatients’ ankle edema ourselves byrestricting salt and giving diuretics, orwe send the patient to other specialistswho can do it for us. We feel good aboutit, especially when patients report thatthe swelling has improved. But do wereally know why we diurese patients?
Many types of edematous states areassociated with symptoms. Pulmonaryedema may lead to respiratory distress.Ascites and increasing trunk girth result in discomfort, sensation offullness, and breathing difficulties. Anasarca in nephrotic syndromecan limit physical activities. When we see mild ankle edema, we oftenstart with dietary salt and fluid restriction, and if this doesn’t work weprescribe diuretics, starting with thiazides followed by more potent loopdiuretics.
In extreme circumstances with worsening pulmonary edemaand imminent intubation and mechanical ventilation, we may considerultrafiltration via dialysis or hemodiafiltration. In some countries, ambulatoryultrafiltration centers are available to edematous outpatients sothat fluid can be conveniently removed without hospital admission. Butdoes removing fluid have any impact on the deleterious effects of theunderlying disease or its progression. Most clinical trials involving heartfailure have failed to show significant benefit of diuresis or ultrafiltration.
Is fluid retention really harmful? A 2009 paper in Circulation detailinga study of 34,107 hemodialysis (HD) patients (conducted by a team Iled) showed that the greater the fluid retention between 2 consecutivedialysis treatment days, the worse the patient mortality. But I wouldargue that the increased mortality also could be due to a harmful effectof the removal of greater fluid volumes by ultrafiltration. Although thereare such controversies related to severe types of fluid overload in heartfailure and HD patients, I am still not sure why I even need to treat lowerextremity edema.
Oral diuretics can cause harm such as hypokalemiaand muscle weakness, hyponatremia and altered mental state, deepvein thrombosis and pulmonary embolism, and many other direct andindirect side effects of these pharmacologic agents. Even restricted saltintake to less than 2 grams per day is associated with worse outcomeaccording to recent findings. So where is the benefit of diuresis?
We physicians often feel obsessed to get the fluid out. There is littledoubt that a swollen ankle doesn’t look good esthetically. With worseningankle edema shoes feel tight especially as the day progresses. Mostof my patients feel happier when I help them to have thinner anklesand nicer legs, and they give me better reviews, so I can maintain myhigh ranking among Top Physicians, Best Doctors, and Best Physicians.That should be good enough reason to diurese.
Kam Kalantar-Zadeh, MD, MPH, PhDChief, Division of Nephrology & HypertensionProfessor of Medicine, Pediatrics and Public HealthUniversity of California Irvine School of Medicine