The human central nervous system discharges carbon dioxide and lactic acid into the cerebrospinal fluid

Background The central nervous system was previously thought to draw oxygen and nutrition from the arteries and discharge carbon dioxide and other metabolic wastes into the venous system. At present, the functional role of cerebrospinal fluid in brain metabolism is not fully known. Methods In this prospective observational study, we performed gas analysis on venous blood and cerebrospinal fluid simultaneously acquired from 16 consecutive preoperative patients without any known neurological disorders. Results The carbon dioxide partial pressure (pCO2) (p