In materials for blood gas reference values, crapo et al. An oxygen level below 88% can be dangerous for any period of time. Are You Unsure About When You Should Put Your Cat Down This Quality Of Life Scale For Cats Can Help You Make The Right End-of-life Infographic Life Life Care However, a large proportion of patients had normal vital signs, even in the last 12 hours of life. End of life oxygen saturation levels . Right heart failure secondary to pulmonary disease (cor pulmonale), not secondary to left heart disease or valvulopathy. If this happens, oxygen therapy can be removed, even if oxygen levels are low. Hypoxemia means that the oxygen levels in the blood are so low that it can harm vital tissue and disrupts bodily function. A person can live many months with o2 sats in the 70's or even lower. Anything below 90% oxygen level is dangerous to your body and require intervention. Spo2 is another oxygen level. Severe hypoxemia occurs once oxygen saturation...