I am often asked about my recent experience of dialysis treatment “what does it involve?”, “how does it work?” and “what does it feel like?” I must say that, despite the shocking nature of the situation, I can’t help but be absolutely captivated and fascinated by how it all works. I never tire of learning about dialysis, medicine and how the body functions. I cannot believe that I am so intrigued by something I gave next to no thought about until now. I could never have imagined that I would know exactly how it feels to have low blood pressure, an elevated phosphate count, or off-the-chart creatinine levels. Having this never-ending thirst for knowledge has been a true gift during all of this. It has kept my mind focussed on the pragmatic and practical aspects and has allowed me some sense of control throughout the dialysis days! I cannot recall being at all anxious regarding the impedance of my first dialysis session; though I must have been! I can only imagine this is because I was still reeling and rung-out from having the access line inserted that I perhaps had no space left to contemplate the mammoth event of dialysis which lay before me.
Part i – how does it work?
The first session soon arrived and I was instantly intrigued by the sheer genius of such an invention. I will attempt to describe, first the procedure and how it works and then, how I felt whilst having it. There are several types of dialysis treatment, peritoneal dialysis *line in stomach*, haemodialysis through a fistula in the arm, or haemodialysis through a line in the neck – which is the treatment I currently receive. Two tubes connect me to the dialysis machine and to ‘hook up’ a process of cleaning and connecting must first commence. Firstly, the protective caps on my access tubes are removed, the ends are cleaned thoroughly with an alcohol wipe, a syringe is attached to the ends, the clamps on the line are opened and a syringe-full of blood is drawn out, which is then discarded. Saline solution is pumped into my line, to clean the inside and the tubes from the dialysis machine are screwed into my line. The machine then sucks my blood out of my body, through my line and into the tubes in the dialysis machine. The dialysis machine is essentially a massive pump. In the centre, a plastic tube is curled round in a loop. Inside this loop is a spinning rotor that digs in slightly to the plastic tubing: as it rotates, it pushes the blood through the tube. The blood then passes through some sort of filter – which I think is to catch blood clots – and then enters the bottom of the dialyser column. The dialyser is a relatively small bit of the machine, but it is where the action happens! Inside this column is some sort of micro porous filter. through which the toxins in my blood can pass, but my blood cells cannot. The dialyser is constantly flushed with water, and this carries away the toxins after they have passed through the filter. Once the – newly cleaned – blood exits out of the top of the dialyser column, it passes down a final plastic tube into the other side of my line and back into my body. The plastic tube in the dialysis machine has a side arm in which more Saline can be added, which is used to flush the remainder of my blood back into my body at the end of the session. There is a second side arm where heparin can be added to the blood to stop it clotting. The speed at which the rotor spins can be adjusted using the touch screen at the top of the dialysis machine. This adjusts the speed at which my blood completes its circuits. The faster the machine pumps, the more times the blood passes through the filter during the session and the more toxins are removed. However, if the blood is sucked out too quickly, it can cause you to feel extremely weird – to put it mildly. In the extreme, it can cause a dramatic drop in blood pressure (basically, the blood doesn’t have enough time in the body to do useful things – like deliver oxygen to the brain – before it gets sucked out again and told to go round the dialysis machine!)
If the kidneys are not performing their customary duties and removing fluid from the body, the Dialysis machine must step up for this task also. For this, the machine has the ability to take some water out of the blood. Unlike say, urea, where you want to get rid of all of it, you want to keep some of your water to avoid turning into a prune. However, every dialysis patient needs to lose some water each session to avoid a rise in blood pressure. So, the more you drink between sessions, the more fluid must be pulled off – and the more fluid that is pulled off, the more taxing this is on the body. The nurse can simply programme an amount of fluid to extract during the session and the machine gets on and does it – I have no idea how this works, but it is very clever!
There’s a myriad of other settings on the machine: they can change the temperature of my blood if I get too hot or cold; they can set a pressure range for my blood where the machine will stop -and an alarm go off – if the pressure in the tubes is too high or too low (typically because I’ve rolled over and am lying on the tubes!); and they can make it monitor my blood pressure through a cuff attached to the machine.
The entire dialysis process takes between four and five hours (including clean up and clean down!) Whether the experience is good or bad, very much depends on the circumstance of the individual. Dialysis is a very complex process and affects everyone differently – and I can only relay my own experience, which I will do in part ii…