Demystifying Kidney Disease for the Average Joe!

Certain types of CT scans will often require that the patient get intravenous (iv) "dye" or contrast to make the organs stand out and delineate them better. This usually would lead to better images with greater sensitivity that help the radiologist in picking up features that would otherwise get missed. The downside however is that this very contrast could sometimes cause damage to the kidneys. The medical term for this is " contrast induced nephropathy " (CIN). What do you then do in a situation where iv contrast is necessarily required? Lets try and understand a few nuances about contrast-mediated kidney damage, and what you can do about it?

BACKGROUND It is estimated that more than 20 million Americans may have chronic kidney disease (CKD). That means roughly 1 in 15 Americans. Subjectively speaking, and for some reason, the rate seems to be even higher where I practice (Bradenton / Sarasota, Florida), but that could be related to the older aged population here. Whether you could "cure" CKD would depend on the cause of kidney disease . Quite often, the cause happens to be a chronic disease that can only be "controlled" (like diabetes or hypertension), but not technically cured. And so is the case with CKD. That is, you can usually not cure and get rid of CKD, but you should be able to control the worsening of your CKD and prevent the fall in your GFR.  I have discussed in my previous posts about how physicians measure your kidneys' function and the concept of GFR. You may want to take a look at the picture of the " GFR meter " again wherein I had mentioned that the needl...

I often see patients in my office who refuse dialysis (should it become necessary) for their advancing kidney disease. I divide these patients in to two categories. The more common category is patients who refuse it because of the "fear of dialysis". They could have trouble understanding dialysis and what potential benefits they could derive from it. They would often make good dialysis candidates who have more to lose than gain by refusing dialysis therapies. The other category is the patient who rightfully refuses dialysis because she or he would not make a good candidate for such treatment. There could be multiple reasons for that. It could be advanced age and frailty, presence of other severe disease conditions like heart failure or metastatic cancer, etc. In such cases, it is hard to always predict if dialysis would add anything to the quality/quantity of life. And often, patients are simply looking at the "big picture". So the questions that come up in ...

I often call kidney disease the "Rodney Dangerfield of Medicine". It gets no respect! Well, outside of the medical community, the same could be said for nephrologists (to a certain extent)! No one is quite sure what they do, or why does anybody need to see one anyway.  For some, we are just another version of urologists. Nephrologists, as the readers of this blog know are physicians who specialize in the diagnosis and treatment of kidney disease, electrolytes, high blood pressure, dialysis, kidney stones, etc. 

In my previous  post , I had talked about how physicians check your kidney function, as well as the concept of glomerular filtration rate (a measure of your kidneys' function, or more accurately, its filtration capacity), or GFR. I want to talk today about an entity that you might have heard before: chronic kidney disease, or CKD.  CKD is a generic, umbrella term. Nephrologists define it as " kidney damage or reduction in kidney function that persists for 3 or more months ". The definition does not include the cause of kidney disease. In other words, whether you have reduction in kidney function from diabetes, or high blood pressure, or a genetic cause, you could still carry a common diagnosis of CKD. This diagnosis is then further subdivided in to stages 1 thru 5, depending on the disease severity. This is where the concept of GFR that I talked about  before  becomes useful.    Take a look at the above picture (courtesy of The National Kidne...

Most people know that getting a stress test is a way to test your heart's function. But how do you test your kidney function? You might have heard doctors mention words like "creatinine", or "GFR" when checking how good or bad your kidneys are doing. Although there are a lot of methods by which the kidneys' performance can be measured, I will explain the ones that are used most often in clinical setting

THE FUTURE IS HERE.....WELL, ALMOST! It has been a while since researchers started working on developing prototypes of artificial kidneys that could literally be implanted in to a human suffering from kidney failure. Theoretically, this kind of artificial kidney would replace the functions of a normal human kidney. It would flush the blood of all metabolic toxins, maintain all body electrolytes in the narrow range necessary for all life processes, produce hormones like erythropoietin (that drives the bone marrow to produce red blood cells), activate vitamin D, regulate blood pressure, etc etc. Yes, these are all some of the functions that those miracles of nature sitting in your flanks, your kidneys, are doing right now.

Cysts, or abnormal pockets of fluid filled sacs, are a common finding on imaging studies like ultrasounds that are done on the kidney. I often see concerned patients in consultation about this finding. The question in that situation is...should you be worried if you discovered that you have cyst/s in your kidney? HOW COMMON ARE KIDNEY CYSTS? Cysts in the kidney are a pretty common occurrence. They tend to get more prevalent in the older age groups. For instance, 11.5% of individuals aged 50-70, and 22.1% of all individuals aged over 70 yrs will have at least one cyst in the kidney . However, the challenge is to identify whether it is a benign age related finding or something as serious as cancer (which can present as cysts). Cysts often will have no symptoms, and will usually be discovered incidentally as part of imaging of the kidneys for unrelated reasons.

I look at the artificial kidney that I talked about in my last post as a sort-of futuristic automaton. It can work (in principle) on the body's internal power (the blood pressure) and does not require the frequent tweaks (again, in principle) that are required with conventional dialysis; thus giving patients more freedom with their lives. However, the technology that really has the trans-humanist in me jumping up and down with excitement is the promise of regenerating a "natural" human kidney in the lab. In Greek mythology, Prometheus' liver would regenerate even after an eagle nibbled on it every day, all while the poor fellow lay chained to a rock (he was lucky the eagle didn't mess with his kidneys, which don't quite possess the same regenerative capacity!). My fantasy is not quite the same, but what I had always conceptualized is that with the advances in regenerative medicine, we might be able to just play God, and "make a kidney", a rea...

Protein in the urine is medically referred to as "proteinuria". As we had discussed earlier, abnormally high amount of protein in the urine is one of the hallmarks of Chronic Kidney Disease (CKD). We also talked about the role of moderate protein diet in preventing CKD progression . But if protein in the urine is just another downstream effect of kidney disease, then why do we nephrologists make so much fuss about treating it?

Earlier, I had talked about the recommended dietary guidelines for patients who have kidney disease . I want to tackle the issue of protein intake in patients with chronic kidney disease (CKD) in a little more detail today because this is an issue that patients seem to be the most confused about. The question is not just limited to how much protein you need to eat to for your kidneys' health and your overall health. What also needs to be realized is that not all sources of protein are created equal, even if they have the same amount of protein. Quality hence matters as much as quantity. 

We are years, if not decades away from creating an artificial kidney . Until then, in an ideal world, every patient with advanced stage-5 kidney disease who needs kidney replacement therapy would get a kidney transplant. Unfortunately, kidneys are a scarce and limited resource. The number of people with kidney failure who could use a transplant far outweighs the number of transplants that actually occur every year. As per the latest USRDS Annual Data Report (2013) , 17,671 kidney transplants were performed in the United States in 2011 (111 fewer than in 2010). Meanwhile, the waiting list had 90,474 patients in line, as of December 31st of the same year. As you can see, the active waiting list is more than three times larger than the actual supply of donor kidneys. In the light of this stark mismatch, desperate patients have to make a decision about the next best option, dialysis. And the question that any proactive patient will ask, and should ask, is what kind of dialysis is the ...