Light-Shielded Hemodialysis Or, Why my blood doesn't see the light

By Miriam Lippel Blum

As with any information you find on the internet do not do this experiment unless you have shown the research to your physician, discussed it thoroughly, and have his or her permission.

Hemodialysis (HD) is usually performed in bright, clinic rooms using transparent tubing to move blood from person to machine and back again. This means during every dialysis session the dialyzor’s blood is exposed to harsh fluorescent lighting. This adds up to more than 450 hours a year (156 treatments x 3-5 hours).  Uniquely during HD blood is exposed to light while it is in use, normally circulating blood is never exposed to light. This, I think, raises a question: does light have an impact on circulating blood?

Research done in Japan, and published in 2005 in the journal Clinical Chemistry, showed that light does have an impact. In Light-Shielded Hemodialysis Prevents Hypotension and Lipid Peroxidation by Inhibiting Nitric Oxide Production, Japanese researchers chronicle an experiment to measure the impact of light on circulating blood. The researchers simply covered the  dialysis tubing and measured changes in nitric oxide (NO) and lipid peroxidation.

Why are these two blood measures important? Together, both are involved in stimulating inflammation which can contribute to a host of problems, e.g. atherosclerosis, decreased epo response, amyloidosis. Individually, too much nitric oxide in the bloodstream can cause hypotension, while lipid peroxidation is a prime suspect for causing vascular damage.

In their experiment, the authors decreased the circulating blood's light exposure by covering the tubing with aluminum foil for the duration of the run. The authors found that the levels of NO were decreased and blood pressures stabilized. And they found the decreased NO inhibited plasma lipid peroxide generation. The implication of this research is that light is not good for blood that is in use. This routine light exposure during HD is likely contributing to dialyzor cardiovascular problems.

This research has had a big impact on me.  When I was on in-center HD, I had terrible intradialytic hypotension that was not related to fluid issues.  No matter how much saline or hypertonic was pumped into me, my blood pressures still would fall dramatically. Often my treatments had to be suspended because my BP was too low to continue.  I also developed severe cardiovascular disease within 9 months of starting in-center HD.  (I was on PD before that.)

My husband, always on the lookout for things that will help my health, happened to come across the Clinical Chemistry article.  I talked with my nephrologist and he agreed, why not see what would happen if we covered my tubing during treatment.  We had some hassles with the clinic but since my doctor wrote an order allowing it, the clinic eventually gave in, after making me address some safety issues (I had to make sure my coverings could be removed quickly in case the machine had an air alarm sound, and the pump needed to be visible).  So I made coverings with fabric and velcro so they could come off quickly and fashioned a little window for the blood pump with polarized plastic (like sunglasses) that would block light but still allow visibility.

The result was remarkable.  My blood pressures stabilized allowing me to have treatment runs uninterrupted by drastic blood pressure drops.  It worked so well that my nephrologist wanted to do some more research, unfortunately there was no funding.

Since that first effort I've fashioned reusable covers out double layers of heavyweight dark fabric. I use these covers along with strategically placed aluminum foil every run. I make sure to fully cover the tubing and dialyzer so that each time I hook up to NxStage I only briefly expose my blood to light. The only time my circulating blood is exposed is during the start and finish of treatments.

I recently talked to Dr. John Agar, about my light avoidance techniques and shared the Clinical Chemistry paper that led my husband and I down this road. Agar had never seen the research and found it very interesting.  He said that some current Australian research showed a heretofore unexplained lower level of NO in patients on nocturnal dialysis.  Perhaps this is because doing dialysis at night, in the dark, reduces the blood's light exposure. Light exposure that would be routine during conventional HD.  This may also be another reason why nocturnal HD seems to be so much better and less damaging to dialyzors.

There is much more research that needs to be done in this area and many questions to be answered.  For example: is there a particular wavelength of the light spectrum that causes the damage?  Or is all light equally damaging?  Does the source of the light matter i.e. fluorescent vs. incandescent vs sunshine?  Does it have to be direct light? Would indirect lighting solve the problem?

Research on blood light exposure could have implications for the provision of dialysis. That the cardiovascular damage seen in dialyzors could be mitigated by something as easy and noninvasive as preventing light exposure is something that should be seriously considered. Research may show that the blood tubing needs to provide shielding or the research may show that redesigning the unit's lighting would solve the problem.

Whatever the solution the dialysis industry needs to address this remarkably uncommented on issue. As for me I have seen (and felt) enough to continue my habit of covering the blood lines and dialyzer.

Comments

[Kathy Heffner]

Very Remarkable..... Great find... Light effects so much and I would not be surprise with the outcomes of further studies....

Kathy Heffner/ Tyefly

[Rich Berkowitz]

Absolutely fascinating find. It goes to show how much we don't know and also how some research remains hidden.

I found another comment quite illuminating and disturbing. Although Miriam's doctor wrote the order, the clinic eventually gave in after first hassling. It seems that many clinics ignore what the dialyzor's nephrologist considers what's in their patients's best interest. We need to assure that the nephrologist remains independent of a clinic and is able to practice medicine and not just adhere to clinic policy.

[Kevin Hartzog]

Interesting, I have heard about fluorescent light bothering lupus patients but nothing about exposure to dialysis patient blood. I am guessing certain individuals are more photosensitive than others and that UV light is more of an issue. I wonder if any "sustainable hospital" blood tubing researchers have thought of this? More research is required. My wife does HHD in a room with only one incandescent lamp on. If needed, I flip on the overhead fluorescent.

[Stephen C. Carr]

I hope the necessary research on blood and light is done soon. About 10 years ago I noticed that plastics in my office and shop became discolored in areas where they were directly exposed to years of fluorescent light. I am sure skin is also damaged by this exposure. I realized that these lamps emitted low levels of ultraviolet light. Subsequently I bought plastic sleeves for the fluorescent tubes in the office. Now that CFL’s are replacing incandescent lamps across the board, we are all getting more UV exposure. Just today it was announced that all UV is carcinogenic.

[John Daley]

Extraordinary. Wow Miriam, very good of you to observe this.

Are the tubes currently non-UV-resistant? This might have to change! Quite a research question you have put.

I breathed a sigh of relief as I read this because most of my 5 years on haemodialysis was overnight at home (I trained myself to sleep overnight on the machine - I needed minimum 6 hours per session and i was also trying to hold down a full time job at the time).

We also had soft lamps with incandescent globes arranged in the room - more for decoration that any UV exposure issues! Although my wife & I also believed that softer lights contributed to a calmer evening atmosphere and helped me eventually wind down to sleep. (We also had 1 powerful spot light on stand by if needed eg if I needed to recannulate in the middle of the night.)

But UV exposure implications! This makes sense Miriam - thanks for raising this question.

[Richard Pachucki]

This is facinating information and definately one to take up with the consultant, thanks.

[Wendy Walter]

It would be great to have a study using the red lights they used in photo labs. This would be an easy change.

[Miriam Lippel Blum]

Wendy,

It would certainly be interesting to see what impact that had. No one currently knows which exact wavelengths of light cause damage so I try to minimize exposure as much as possible.

Miriam

[sunglasses]

I love reading your post. It's very informative. I've leaned about hemodialysis. I'm a nursing student and I'm doing a research, and this has helped me alot. Thank you for sharing.