Kidney Stones and Kidney Failure

A recent article in the British Medical Journal says that kidney stones can double the risk of a person requiring dialysis or transplants. The study looked at over 3 million patients in Alberta, Canada over a 12 year period. They reported that those with a history of kidney stones were twice as likely to have serious kidney problems later in life when compared to people who had never suffered from kidney stones. Age was also an important factor (perhaps giving time for more damage to occur?) as those under 50 had more problems than those over 50; women seemed more susceptible too - women under the age of 50 years who had a history of kidney stones were four times as likely to later develop kidney failure.

It should be noted that the actual number of those who ended up requiring dialysis was low, but the risk was greater than in the normal population. When you are passing a stone through a kidney, there is definitely the potential for permanent damage.

People could try to decrease the likelihood of the development of kidney stones by decreasing their sodium intake, drinking more water and, if needed, taking certain medication, the researchers suggest. It has been previously observed that those who develop kidney stones have kidneys that don’t function at optimal levels, which is a factor in the whole issue.

Chronic Obstructive Pulmonary Disease Raises Dialysis Patient Death Risk

Chronic Obstructive Pulmonary Disease (COPD)is the occurrence of chronic bronchitis or emphysema, a pair of commonly co-existing diseases of the lungs in which the airways become narrowed. This leads to breathing problems. Smoking is one of the commonest causes of COPD. But if a patient starts dialysis, it increases the risk of death and decreases the chance that the patient will receive a transplant, according to recent research.

The research covered 769,984 US dialysis patients over a nine year period - with a large pool like this, the results are very much more reliable. It found that those suffering from COPd had a 20% increased risk of death compared with those who did not have COPD. If the patient also smoked, the risk increased by 28%. Smokers also had a lower chance of getting a transplant compared to non-smokers.

GranuFlo and NaturaLyte Withdrawal

Granuflo and NaturaLyte are products made by Fresenius, as buffer solutions in the final dialysis solution. Buffers control the pH of the solution and blood. There is concern that incorrectly mixed dialysate could lead to problems for dialysis patients.

Both products are an acetic acid / sodium acetate mixture. Buffers are a mixture of a weak acid and its sodium salt, and the choice of acid and salt determine the pH range over which the buffer will operate.

The first problem is that the body can metabolize acetate ions to carbonate and hydrogencarbonate (bicarbonate) ions, thus raising the level of bicarbonate in the blood. And bicarbonate ions are are part of one of the body's own buffer control systems. Altering the bicarbonate levels can lead to a pH imbalance and metabolic alkalosis - the blood is too alkaline during and after dialysis.

And metabolic alkalosis is an independent risk factor for low blood pressure, low blood oxygen, high blood carbon dioxide, heart rhythm problems, and sudden cardiac death.

Now the second problem.

A leaked memo from Fresenius was made available to the FDA. In it, Fresenius warned doctors at its company-owned clinics of the risk of GranuFlo side effects when using these concentrates. It advised its doctors to check bicarbonate levels in patients before dialysis, and to adjust prescriptions as necessary. The company failed, however, to warn outside clinics of the risks associated with GranuFlo and NaturaLyte.

Eventually the FDA issued a class 1 recall on these two products.

One interesting result I found was this article, dated 2009, claiming that acetate buffers are an old-fashioned type of buffer and, on my reading of it, had been replaced. So why were Fresenius still producing these products at all? Well, neither product is dangerous in it's own right, it is the risk of errors when making up the final solutions to administer to patients that is the problem.

Other acid concentrates are primarily just acetic acid. As a PhD chemist I have to point out that the acetic acid in these concentrates will interact with any sodium in the blood to result in sodium acetate being present in solution. Thus the acetate ions are present once again and metabolism to bicarbonate will still occur. Presumably the amount of acetate ions will be so much lower in these cases that the conversion will be much less of a problem.

Problems when patients start dialysis too soon.

The glomerular filtration rate (GFR) quantifies the rate at which filtered fluids are processed by the kidneys. By medical consensus, a GFR of 10 is deemed “early” for dialysis. But recently, the number of elderly people (those 75 and over) who started dialysis when their GFR was lower than 10 increased from 1 in 4 (in 1996) to more than 6 in 10 (in 2009), according to an article at The Journal of the American Medical Association.

It is suggested that with medics receiving a referral fee from dialysis centres, patients were being referred sooner than necessary. Whether or not this is a factor, the article says that early introduction to dialysis is not justified. Elderly patients with age related decreases in muscle mass may have higher GFR due to this problem instead. And being subjected to dialysis can lead to a higher risk of death, while a controlled trial found no benefit from starting dialysis early. Indeed the article stated that for those over 80, they were more likely to die from other causes before starting dialysis.

The article ends with the following statement:
"The public perception that pursuit of dialysis is always in patients' best interest should be replaced by a more realistic view of the “sad truth” about early dialysis initiation in elderly patients."

Dialysis demand increases after elective surgery

Elective surgery - surgery which can be scheduled in advance as it does not involve a medical emergency.

The number of patients needing dialysis after major elective surgery has tripled since 1995, a Canadian study reported here suggests.

Researchers reviewed data on 552,672 patients in Ontario who had elective major surgery in the province between 1995 to 2009. Out of this group, 2,231 received acute dialysis within 14 days after surgery. This represents an increase from 0.2 percent in 1995 to 0.6 percent in 2009. An extra 0.4 percent might not seem much, but it's 1487 more people!

According to kidney specialist Dr. Amit Garg of London Health Sciences Centre, when someone develops the complication and is sick enough after surgery to need dialysis, 40 per cent will unfortunately have died at 90 days. So it's a very high risk of death in patients who develop this complication. And in those who survive 90 days, one fourth are now left with permanent kidney failure needing ongoing maintenance dialysis and those outcomes haven't changed in the last 15 years.

Older, sicker patients may be higher risk of acute kidney injury, the researchers said, with people who already had weak kidneys, or high blood pressure or diabetes before the surgery at highest risk.