Since a Bipap machines works on two pressures that are IPAP and EPAP so in a bipap machine, there are 2 pressures range: IPAP pressure : Average pressure range, 4 cm H2o - 25Cm H2o EPAP pressure : Average pressure range, 4 cm H2o - 25Cm H2o Average pressure range in bipap machines is 4 cm H2o - 25Cm H2o thats mean pressure can be increased up to 25 cm H2o, based on the patient's response. What should be the IPAP and EPAP this doctor will prescribe.