My father admitted to hospital 1/mo ago..very low blood oxygen level (around 70)..Has per-existing Vascuilitus (Buerger's ??) as well as Hypothyroidism (daily synthetic pill)...diagnosed after bad pneumonia in 2000. Believe he currently has pulmonary hypertension..barrage of tests have been done, incl lung and lymph biopsies, angiogram...no viral/cancer/blockage present... i don't believe that a diagnosis is confirmed, he is being treated for D.I.P. (DESQUAMATIVE INTERSTITIAL PNEUMONIA), as follows: 1.Solumedrol, 2. Epogen, 3. Mycophenolate, 4. 24hr/day oxygen (recently down to level 5/6 from 10), Darvocet & Vicodin for pain from biopsy sugery week ago. We believe that the veins going into the lungs are being affected by inflamation, result in less than normal blood exchange out of the lungs.. (heart been working very hard to try keep blood flow rate normal in order to get corrrect amount oxygen thruout sysem-- but was unable to...summized that the veins are constrited, therefore treatment with meds mentioned above). Father curently knows some of the things that drive his blood ox level down (bowel movements,little constipated, waving arms wand, a few other), into the high 60's (he recover's to low 90's within minutes after getting back to bed. What he can't find is " The Required Blood Oxygen Level (minimum)in order to sustain life, w/o 24/7 oxygen mach.(ie..b.o/68 can survive with supplenental treatment.? b.o./75, may be fine,.....but @ b.o./66, you would die. What's that "Magic Number" cliff. The goal is 95+, but what does it take to stay alive? TYTY for any assistance