Issue 4 Page 2

The Facts about Home Oxygen Therapy from Dr Alfie

Home oxygen (O2) therapy is prescribed, to people with very severe lung disease, when a person’s lungs are unable to maintain an adequate supply of O2 and when this can not be improved by other measures. The blood O2 level is measured by an oximeter probe on a finger or by an arterial blood sample. The normal oximeter value is 96-99 units (%) and the normal blood gas level for O2 is in the range of 80 to 100 units (mmHg). Note that the 2 sets of units are for different scales. Home O2 is usually considered if the oximeter value is 88% or less or if the blood gas value is 55 mmHg or less.

When O2 is prescribed, it is recommended for use all night while asleep (when the blood O2 levels fall) and for a few more hours during the day, aiming for a usage of 12 to 18 hours per day and night. Medical studies showed that by improving their low O2 levels, O2 users felt better and lived longer than similarly affected people who did not use O2. “Continuous” usage of home O2 is achieved economically using “O2 concentrators”. These “concentrate” O2 in the air by extracting most of the nitrogen.. They are large, need a power supply and are designed to be positioned close to where the user is sleeping or working. Most users of home O2 do not need it for 24 hours per day.

O2 is restricted when exercising because of the high cost of portable O2 and there is not always a clear benefit. Used at the common flow rate of 2 lpm, a small C-cylinder lasts about 4 hours. Special regulators which can double this time are expensive. Portable O2 is needed by all home O2 users when flying to boost the lowered blood O2 levels.

Home O2 is restricted because of danger and expense. Dangers include explosions from mishandling compressed gas cylinders and fire hazards from using oxygen near flames. O2 concentrators cost about $3 per day to rent. They can deliver up to 5 litres per minute of O2 for 24 hours per day. Cost of electricity is subsidised. Delivering portable O2 at 2 liters per minute is between $2 & $5 per hour (20 – 50 times more expensive). There are 3 costs involved with cylinders: rental of the cylinder and regulator (about $1 per day), the delivery of the cylinders (about $25 per delivery) and the refill of empty cylinders (about $10 per C- cylinder). Supplying O2 at 2 lpm for 12 hours per day would cost over $1,000 per month via cylinders compared with $100 via a concentrator. Home O2 is prescribed to about 500 Tasmanians at a cost of $500,000 per year. Home O2 is not prescribed to someone who is still smoking because it is a waste of money and because of fire and explosion hazards.

Issue 4 Page 2