by Andy Mosson – Renal Technician, Oxford Kidney Unit

Haemodialysis was first carried out in Oxford in the mid nineteen sixties s using a Travenol RSP machine.

The first Oxford dialysis patient reported in the Oxford Mail in 1967

This type of machine consisted of a large tank in which the dialysate was mixed by hand. The dialysate was then pumped through a coil dialyser to perform the treatment. By the late sixties haemodialysis machines were being produced which mixed a concentrated solution of salts with mains water and avoided the need for a large tank. A British version of the Kiil dialyser, manufactured locally by Meltec based at Bourne End, Buckinghamshire was also becoming available to replace the coil dialysers. These Meltec dialysers used large sheets of semi permeable membrane (cuprophan) to separate the blood from the dialysate and through which ions and water could pass to enable dialysis to take place.

Patient dialysing at home in the 1970s using the Meltec multipoint Kiil dialyser.

The start of home haemodialysis

In 1967 a six bedded dialysis unit was opened at the Churchill Hospital in Oxford and by the early seventies a home dialysis programme, covering six counties around Oxford, was in full swing. Because of the size of the dialysis unit, long term in-house treatment of patients was not possible and patients were trained for home dialysis which was the only option for long term treatment. The reusable Kiil dialyser made home dialysis economically feasible. The original Kiil required ten hour treatments three times a week, but this was replaced with a more efficient six hour Kiil in the mid seventies. By 1973 there were 120 home patients in the region. The dialysis machines used were made by Lucas Medical, Cambridge Instruments and Dylade. All three machines were manufactured in the UK.

A patient dialysing using the Lucas Mark 1 machine

Technician team

This programme was supported by an in-house technical team with a workshop in a Nissen hut located close to the  dialysis unit although a poor power supply to the workshop created problems. The Churchill Hospital was originally an American Army hospital so rows of Nissen huts outside the main building were in wide use. There were five technicians at that time supporting the home dialysis programme.

The Oxford technicians workshop in the 1970s

Dialysis machines in the 1960s and 1970s

The dialysis machines themselves were certainly not the sophisticated systems they are now. Blood and anticoagulant pumps were add-ons stood on top of the machines,  although home made brackets were designed by the technicians to better mount the pumps. The safety monitoring was very basic: dialysate temperature and conductivity to check the composition of the fluid, a blood in dialysate detector to detect the frequent rupturing of the Kiil membrane, and venous line pressure. The blood leak detection was achieved by shining a light through a large glass tube – patients had to regularly clean this tube to prevent false alarms due to deposits on the glass. One home patient, an engineer, solved the problem of false blood leak alarms – he opened the back of the machine and shone a lamp on the blood leak detector – this, of course, rendered the alarm system useless! This same patient also decided he could shorten his treatment times. He still had his ten hour Kiil at home so he mounted it on top of his six hour Kiil and ran the two dialysers in series! This was a time when pre-assembled tubing sets were not produced and tubing sets were made up by patients as required so the patient had access to everything he needed to connect the dialysers.

It was only later that arterial line pressure monitoring was added, initially a soft chamber in the blood tubing which, under suction, would flatten and could be observed. Later a switch was added to detect the flattening of the chamber which would generate an alarm. This, again, was somewhat ‘hit and miss’ and required regular adjustment to function correctly.

It was not unusual to build things in-house. At Oxford this included redesigning an existing air bubble detector to make it more effective and building a single needle control system from scratch. Looking back, the safety systems supporting these projects were somewhat dubious and the introduction of quality systems was still in the future!

The practicalities of home haemodialysis

At that time, home dialysis was in a much more clinical setting than it is now with many patients dialysing in a fitted-out portakabin craned into the garden. This would be complete with its own power and water supply. Water treatment was very basic – just a water softener! The adverse effects of calcium in the dialysate had already been recognised but the negative effects of aluminium had not yet become apparent. Pyrogenic reactions were not unusual. It was not until the early 1980s that de-ionisers and then reverse osmosis (RO) units were becoming available to treat the water supply for home patients. De-ionisation removed electrolytes including aluminium but RO had the advantage of removing both electrolytes and the microbiological material which could lead to pyrogenic reactions.

Although the Kiil dialyser was reusable, it needed a certain amount of work to achieve this.  After every treatment the residual blood had to be washed from the membranes and then the Kiil was filled with formaldehyde to be stored until the next treatment. After a number of treatments, the residual blood building up on the Kiil membranes became too great and dialysis efficiency became inadequate – typically three to six treatments would be achieved before the membranes would need replacing. To determine when this was due, patients would have to test the volume of fluid held in the Kiil which indicated the state of the membranes. Replacing the membranes was an additional task for the patient and their helper to perform and would typically be a Sunday job! Membrane replacement consisted of dismantling the Kiil (using a large torque wrench provided), discarding the membranes, and carefully placing two pairs of the cuprophan sheets onto each of the Kiil layers.

Building the Kiil dialyser at home

The success of this procedure was determined by a pressure test which frequently failed. The failure could be due to damaged membranes or gaskets in the Kiil failing to seal. The procedure would have to be repeated until success achieved which could also include replacing the gaskets if it was judged to be the problem – again, a patient task.

This meant a very busy on-call support for the technical team and was generally a very stressful time for all concerned – three dialysis treatments were unavoidable but to spend a fourth day fighting to rebuild the Kiil was very traumatic. It was often a tearful telephone conversation sometimes leading to the offer of a visit to help. With the area covered, this could also be well over an hour’s journey to reach the patient – all before the availability of mobile phones!

A technical on-call programme was an essential requirement to support home patients and, with the number of home patients and the crude nature of the equipment, it was not unusual for the on-call technician to receive four or five calls in an evening although an immediate home visit would only take place in an emergency. The norm would be a repair visit next day. Now, modern dialysis machines have very sophisticated self-test programmes which may prevent dialysis commencing. These programmes did not exist on the early machines and failure after the start of treatment was more common. Having to tell a patient to discontinue treatment was very painful.

Modernisation in the 1980s

By the early eighties, the older British machines were being replaced by Cobe and Gambro fully integrated systems. Pretty much the whole home fleet of machines in Oxford were replaced by Cobe machines bought with charity money raised by the patients themselves.

These machines, and the replacement of Kiils with the small disposable single use dialysers, gave the patients an easier life although the stresses of home dialysis were never underestimated.

It also, sadly, led to the end of British manufactured products.

Last Updated on April 29, 2024 by John Feehally