Your CPAP will use between 20-30 amp hours of battery in a 8 hour period depending on the setting. 200 watts of solar will deliver on average (with no shade) about 60 amp hours of recharge per day. If you have a single deep cycle battery rated at 120 ah, you would not have a problem running your CPAP using solar.
2007 Surveyor SV230 - 200 Watts Solar/MPPT Controller - 230 AH Battery Bank - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting - Boon Docking 99% of the time.
2009 F150 - 5.4 Litre - 6 speed - Tow Package