Dr Garrod and colleagues have described a pulsed flow oxygen delivery system for use during exercise by patients with chronic obstructive pulmonary disease (COPD).1 They found the device to be four times as economical as nasal cannulae for the same increase in walking distance. On the debit side, the weight of equipment carried by the patient was increased from 2.9 kg to 3.7 kg, and at a cost of £410.

Old fashioned remedies are often looked down on, but an equal benefit could have been achieved, without the disadvantages, by using a mask of the type designed by Haldane in 1917.2

By comparison with nasal cannulae, this device similarly resulted in fourfold economy when maintaining a raised alveolar oxygen tension in normal subjects.3 Its use led to a significantly greater improvement in walking distance in patients with COPD compared with the other devices which were tested.4 ,5

The Haldane type mask fell out of use because, with a limited demand and low price, the manufacturer had little incentive to maintain a stock. Now, with greater awareness of the likely benefit, there might be a case for trying again.