In a basal metabolism measurements timed at 6.0 minute,a patient exhaled 52.5 litre of air,measured over water at 20oC.The vapour pressure of water at 20oC is 17.5 torr.The barometric pressure was 750 torr.The exhaled air analysed 16.75 volume % of oxygen and the inhaled air 20.32 volume % of oxygen,both on dry basis. Neglecting any solubility of the gases in water and and difference in the total volume of inhaled and exhaled air,calculate rate of oxygen consumption by the patient in mL(STP) per minute.
\(\frac{(750-17.5)\times 52.5}{293}=\frac {760\times V}{273}\)
From the above, V can be calculated at STP.
O2 consumed = \(\frac{V}{100}\times (20.32-16.75)\)
The above volume of O2 can be converted to mL/min.