Usually, a human is born with two kidneys, each equipped with roughly a million filtration units called nephrons. The filtration plants carry enough working capacity to outlive the span of human life. Most of us take our kidneys and their working for granted, but kidney function assumes immense importance for a kidney disease patient. Ask a kidney disease patient and he would be willing to give anything just to hear that his kidneys can get better.
Therefore, it is crucial to learn whether the decline in your kidney function is permanent or reversible. So, whenever you see a drop in the working of your kidneys, discuss with your doctor the following reversible causes of kidney function loss.
DEHYDRATION — dehydration and the resulting dip in the kidney are very common. Many patients have to endure unnecessary stress just because they checked their kidney function on a hot, dry day without being well hydrated, and it turned out to be abnormal. The network of blood vessels in our body contains about 5 litres of blood at any given time. The blood has many components, but two are essential for kidney function: the fluid part called plasma and red blood cells. If any of these two get too low, your kidney function may drop. Common causes of a decrease in plasma level are decreased fluid intake, excessive sweating, vomiting and diarrhoea. On the other hand, both plasma and red blood cells drop when a patient bleeds. In most cases, dehydration is not severe and you can completely recover from this state by drinking more water. Sometimes, the loss of fluids is so severe that you must go to a nearby emergency room for intravenous fluids to compensate for the lost volume in your blood vessels. Regardless of the severity, dehydration is unlikely to cause permanent kidney damage.
MEDICATIONS — many medications interfere with kidney function, primarily by altering the diameter of blood vessels within the kidney, resulting in a decline in kidney function, usually a temporary decline. Once the offending drug is removed, the kidney function recovers. Still, the loss of function can be permanent if you fail to take timely measures. Furthermore, these agents disturb kidney function more when you are dehydrated. Therefore, let’s look at some common drugs that cause a reversible decline in kidney function.
ACEIS & ARBS — ACEIs medications usually have -pril at the end of their names, as in Lisinopril and Ramipril. ARBs typically end with -tan, like losartan and Valsartan. These drugs are the best tools in our toolbox to preserve kidney function. Though commonly touted as blood pressure medications, these two classes not only control blood pressure but protect kidneys from ongoing damage by making dynamic changes inside the kidney. As a result, they slow down the progression of kidney disease and even prevent the future need for dialysis. However, a slight drop in kidney function is commonly expected after their initial use, a trade-off that helps delay or may even prevent a future need for dialysis. The best strategy to prevent a drop in kidney function from ACEIs/ARBs is to hold off using other medications like painkillers and stay hydrated.
PAINKILLERS — pain medications in this group, commonly called NSAIDs, including Motrin and Naproxen, drop GFR by decreasing blood flow to the kidneys. This side effect is more marked in those patients who are dehydrated, taking ACEIs/ARBs and/or have heart and liver failure. Prolonged intake of these drugs can permanently damage the kidneys. Therefore, using them for more than five to seven days should be avoided. If some other medical condition mandates taking these medicines beyond that period, you should do so under the supervision of your physician, who would monitor your kidney function for any signals of damage.
OTHER MEDICATIONS — the list of medicines harmful to kidneys is endless and beyond the scope of this article. But a couple more salts we use daily need to be discussed. Many show concern about the safety profile of Aspirin in CKD. First, Aspirin should not be used as a pain relief medication because it increases the risk of bleeding. However, the low dose of Aspirin, 81 to 162 mg, used in heart and stroke patients, is okay to use, even in patients with reduced kidney function. Another commonly asked medication is Proton Pump Inhibitors, a few examples of which are Omeprazole, Pantoprazole and Lansoprazole. Some studies have shown that these drugs adversely affect the kidneys, while others reveal no such evidence. Anyways, these reflux drugs should be avoided in CKD patients.
DYES USED IN RADIOLOGY — sometimes, CT scans require an intravenous dye, commonly called IV contrast, for better images. Unfortunately, this contrast may temporarily or permanently worsen your kidney function. The newer versions of contrasts are becoming safer and safer for the kidneys, but still if you have kidney disease, all procedures requiring a contrast material should be done under the supervision of a nephrologist.
BLOCKAGE OF URINE FLOW — each kidney pours its urine into a narrow pipe called the ureter. Both ureters drain into the bladder. The urine then comes out of the body through the urethra. Any obstacle on this pathway can hamper the urine flow, leading to back pressure in the kidneys and a decline in their function. One common cause of such obstruction is an enlarged Prostate, a common problem in older patients. Decreased kidney function in such cases is reversible and resolves completely once the prostate is taken care of. When they obstruct both ureters, kidney stones can cause similar problems and need timely removal to prevent permanent kidney damage.
REVERSIBLE KIDNEY FUNCTION AFTER STARTING DIALYSIS – while getting off dialysis in patients with chronic kidney disease and permanent kidney damage is not possible, recovery is expected for patients with acute kidney injury. Therefore, if you develop an acute kidney injury that requires dialysis, always ask your physician about the chances of getting off dialysis. Whether in the United States or Pakistan, patients with a sudden fall in kidney function requiring dialysis undergo a tiring transition from a hospital to a dialysis centre. Imagine a patient from Sialkot who ended up in a hospital in Lahore, where he got started on dialysis after an acute kidney injury which is presumably reversible. Once he returns and joins a local dialysis unit, the new team either has no records of his previous proceedings or is unwilling to look into them. So the patient continues dialysis, unaware that he would have been off dialysis had his kidney function been checked. Unfortunately, this sad scenario happens a lot.
The writer is an award-winning internist and nephrologist. He tweets at @awaiszaka