Oxygenation

This chapter discusses the rationale for administering increased oxygen concentrations in neurosurgical and non-neurosurgical patients alike, as well as the harms of doing so. Cerebral blood flow (CBF) has multiple determinants including arterial blood pressure, partial pressure of carbon dioxide, and arterial oxygen content. A purported benefit of increased perioperative oxygen concentrations is a decreased incidence of surgical site infections, a complication that results in considerable morbidity. The chapter describes the special neurosurgical and neurocritical care issues: traumatic brain injury, carotid endarterectomy, venous air embolism, neurogenic pulmonary edema and spurious pulse oximetry readings. The clinical significance of free radical formation during exposure to increased FiO2 for the duration of a surgical procedure, even a lengthy neurosurgical procedure, is unclear. The Society for Ambulatory Anesthesia in 2007 did not recommend using increased FiO2 to prevent postoperative nausea and vomiting (PONV).