What is Chronic Kidney Disease?

Chronic Kidney Disease (CKD) is an alteration in the normal function of the kidneys caused by a chronic process and it is usually not reversible. Functionally, the kidney tissue is less capable of performing its functions which include: the filtration of blood, the control of the acid base status, electrolyte concentration control, fluid and blood pressure management, generation of erythropoietin for red blood cell production and  activation of vitamin D.

The processes that most commonly result in CKD are persistent uncontrolled hyperglycemia from diabetes mellitus, persistently elevated blood pressures, acute or subacute inflammatory conditions of the kidneys and genetically mediated anatomic abnormalities such as polycystic kidney disease (PKD). These processes result in scarring and fibrosis of the kidney tissue, with loss of renal cells in the cortex and medullary portions of the kidneys. 

Chronic kidney disease is usually classified in stages, going from I to V. The function that has been chosen to  assign the stages is the filtration function, measured as a variable called glomerular filtration rate (GFR). Although the kidney has many different functions, they are related to each other. The relationship is not perfect, but is is safe to say that if there is a reduction on the filtration function function of the kidneys, the other functions will be affected, in variable degrees. It is also possible that certain functions of the kidney may be affected with little change in other functions, for example, there are conditions that involve abnormalities in the handling of potassium or acidity without a change in the filtration function or generation of erythropoietin, however, these conditions are not too common.

The final stage of CKD is called end-stage renal disease (ESRD). At this stage, renal replacement therapy (RRT) becomes necessary. RRT includes dialysis (in its different modalities) and renal transplantation.

Marco A. Ramos MD

3 Common Ways Kidneys Get Damaged Acutely

The kidneys are very delicate organs. As it can be seen in a previous post, they are in charge of many different functions and need to have a good supply of blood at all times in order to perform appropriately. 

1. The most common reason the kidneys get damaged is when the blood supply decreases. This happens when an individual loses fluids through diarrhea, vomiting and does not replenish its fluids with salt-containing fluids. 

2. Certain pain medications, can affect the internal blood flow of the kidneys. If these medications are taken and the body is not adequately hydrated the blood flow to the kidney cells can severely decrease and cause kidney damage. The type of pain medications belong to a category called non-steroidal anti-inflammatory drugs. Common examples of them are ibuprofen, naproxen and ketorolac. Other medications, taken when the body is not well hydrated can also damage the kidneys these include diuretics and blood pressure medications called ACE-inhibitors (examples: captopril, lisinopril, enalapril) and angiotensin receptor blockers (examples losartan, valsartan, irbesartan).

3. Finally, the kidneys can get damaged by a substance that is necessary for certain diagnostic procedures. The use of radiocontrast for coronary angiograpahies or CT scans can damage the kidneys if they are already chronically damaged or if the patient is not adequately hydrated.

There are other causes for acute kidney damage. The post concentrates in the common ones.

All these causes are usually temporary and the faster they are corrected, the better the chances of avoiding longer damage. Whenever there is a change in the level of fluids a body, the balance has to be restored. Do not hesitate to talk to your doctor or go the the closest Emergency Department if you feel at risk.

Marco A. Ramos MD

3 Situations to be Careful if Taking Diuretics

Taking diuretics has become one of the cornerstones of the treatment of hypertension and heart failure. Although it has benefits, it has risks too. Here are 3 situations that any person taking diuretics has to be watchful for.

People usually follow the doctor’s recommendations and take the diuretics faithfully once, twice or thrice a day. However, if the person taking the diuretics develops, diarrhea, vomiting or loses its appetite, he or she runs the risk of developing low blood pressure for volume loss in the vascular system. This can cause dizziness, syncope (passing out) or kidney failure.

Diuretics always carry the side effect of losing potassium and/or magnesium though the increased urine production. The best way to avoid this is to have a balanced diet or to take supplements. Low potassium or magnesium can cause dangerous cardiac arrhythmias or muscle weakness.

A low sodium concentration in the blood is also a potential consequence of the use of diuretics. This can happen if the person taking this type of medication drinks too much water while replacing the losses through the urine. Low sodium concentration in the blood can cause headaches, loss of balance, and if severe, lethargy, seizures and death. All diuretics can be associated with low sodium concentrations, however, the thiazide type of  diuretics are more commonly  related to this problem.

All medications cause side effects. Always talk with your doctor regarding these when starting a new one.

Marco A. Ramos MD

The Three Most Common Causes of Kidney Failure

The kidneys are very important organs in the human body. They perform many functions other than just make urine (see my blog post published on October 23, 2014). The kidneys can lose 80-90% of their total function and there could not be any symptom, however, if more than that is lost, dialysis or kidney transplantation are needed in order to survive. So, what causes kidney failure? The list is long, however, the three most important causes are as follows:

The number one reason for people requiring dialysis is diabetes mellitus. 38-45% of all cases of kidney failure are caused by this condition.

The second cause for kidney failure is hypertension (elevated blood pressure). 25-28% of the people who require renal replacement therapy have hypertension as its main mechanism. We have to keep in mind that many diabetics are hypertensives too.

The third cause for kidney failure is glomerular diseases in general. Many of these conditions are autoimmune and have long and complicated names and can only be diagnosed accurately by a kidney biopsy. 10-15% of dialysis cases are from these conditions.

These three causes account for about 85% of all reasons for going into dialysis. There are other situations like genetic conditions,
medication reactions or toxicity from herbal “remedies” that can also cause the kidneys to fail. Since kidney dysfunction rarely produces symptoms until it is too late, it is important to undergo yearly physical examinations that include basic laboratory workup that would detect that the kidney is failing. 

Marco A. Ramos MD