NPPB and normal pressure hydrocephalus: Moreover, we observed significant differences in TB, IB, BNP, serum albumin (ALB), arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2), arterial oxygen saturation (SaO2), HCO3−, forced expiratory volume in the first second (FEV1), FEV1/FVC, and GOLD stages between COPD-PH and COPD-NPH patients from HA (P < 0.05) (Table 2).