Drugs and the central nervous system

Abstract

As in all other organ systems, prevention of hypoxia is the aim in the management of central nervous system pathology, to prevent or minimize secondary brain damage and neuronal dysfunction. In the normal brain, auto-regulation, oxygen and carbon dioxide levels are the main determinants of cerebral blood flow. Once the physiological regulatory conditions have been breached, such as in trauma, bleeding or infection, the intracranial pressure rises and caregivers intervene to maintain adequate oxygenation and ventilation, and try to ensure that cerebral blood flow (and thus oxygen delivery) is adequate to meet the metabolic demand of the brain. This is more crucial in the brain than in any other organ in the body because its high metabolic requirements render the brain extremely sensitive to hypoxic conditions. The drugs used are mainly to modulate cerebral metabolism, cerebral perfusion pressure, cerebral blood flow and brain volume (cerebral edema). Adequate knowledge of cerebral physiology and the pharmacological effects of these drugs is vital to provide optimum care in patients with cerebral pathology.