To the Editor: It has been known for a long time that washing soda (crystalline sodium carbonate) is effective for removing fluid from joint effusions. The crystals are simply wrapped in a tea towel, crushed with a rolling pin and wrapped around the joint overnight. In the morning the sodium carbonate is rock solid and the joint effusion has markedly improved.

I was discussing with one my patients her problem of gross upper-limb lymphoedema after surgery and radiotherapy for breast cancer to the axilla. She went home and made an appropriate pack of sodium carbonate, which she wears overnight. She can now use her arm throughout the day. Obviously, the lymph fluid reaccumulates because her lymphatic system is well and truly obstructed.

This patient spoke to several other patients in the Day Centre at the Monash Medical Centre, who tried this in addition to other exercises for lymphoedema, and they have found it to be extraordinarily effective. One woman had gross oedema of her hand, which rendered it useless: she simply immersed her hand in a solution of sodium carbonate and thus dialysed the fluid from her hand. Thereafter she could use her hand for 12 hours before significant amounts of fluid reaccumulated.

While this is obviously not the perfect solution to lymphoedema in patients with breast cancer, anything that may help them is worth noting. Perhaps a suitable linen device could be made which would cover the whole arm at night.

Evidence for the use of this simple dialysis treatment is currently anecdotal. It might be appropriate to design a clinical trial to determine whether this method has potential in treating this extremely troublesome form of lymphoedema.