| Intravenous Drugs | Inhalational Drugs | Muscle Relaxants |

The anesthetic management of neurosurgical patients is based on the knowledge of the selected drug's influence on the central nervous system (CNS) physiology. The specific anesthetic regimen is a combination of drugs that favorably affects cerebral hemodynamics, cerebral metabolism, and intracranial pressure (ICP) to provide good operating conditions and to enhance the probability of a quality outcome. Most anesthetic drugs have been studied in this regard and, as new drugs are developed, their effects on cerebral physiology will be elucidated. The effects of anesthetic drugs on cerebrospinal fluid (CSF) volume (as determined by the rate of formation and the resistance to reabsorption) have also been determined.
Few studies have addressed the effects of anesthetic drugs on spinal cord physiology. This could be in part because noninvasive methods of measuring various aspects of spinal cord physiology in the human are not available so that most of the data have been derived from animal studies. Although it has been assumed that the effects of anesthetics on the spinal cord mimic their effects in the brain (and this is likely to be qualitatively correct), to make true comparisons, investigators must examine both brain and spinal cord parameters simultaneously.