What physiological factors can affect oxygenation?
Anemia or inhalation of a toxic substance: decrease O2 carrying capacity
COPD, pneumonthorax: Upper/lower respiratory obstruction
Shock, severe dehydration, increased CO: Hypovolemia
Fever, exercise, anything that increases metabolic rate
Conditions that affect chest wall movement: fractures, pregnancy, musculoskeletal abnormalities, trauma, neuromuscular (MS, MD) or CNS alterations (OD on heroin and opidate drug use)