Hi everyone,please help me. After my husband been to the hospital breathless and the oxymeter kept showing low sats but the blood test showed normal sats i had a feeling they did it wrong( which they did), i asked to do it again and the sats were low. Now we want to travel to the UK to hospital for some tests, we rented portable concentrator but to go on plane we need a letter from doctor. Our doctor in here is giving us one, but she doesnt know how it should look like and what to write in it( she never did it before). Can anyone who travels with concentrators tell me what should be in that letter. Thank you.