Resuscitation of the Penumbra Area – Lucida in the Brain of Traumatic Brain Injury

Abstract

Background: Cerebral hypoperfusion is a major cause of brain ischemia, both global and focal. In focal ischemia, there are three main zones: the ischemic core, which undergoes permanent damage; the penumbra, which remains salvageable; and the area with normal perfusion. A decrease in blood flow and disruption of cerebral autoregulation can convert the penumbra into an infarct if reperfusion is not promptly achieved. The penlucida region represents tissue capable of spontaneous recovery without intervention, whereas the penumbra requires immediate action to preserve neuronal viability. Neuronal injury in ischemia primarily results from energy production failure due to impaired oxidative phosphorylation, increased intracellular calcium, excessive glutamate release, and the formation of free radicals that lead to excitotoxicity and cell death through necrosis and apoptosis. Resuscitation of the penumbra–penlucida area aims to restore perfusion and oxygenation before irreversible damage occurs through the application of the neuroanesthetic-based ABCDE principles (airway, breathing, circulation, disability, exposure). Maintaining airway patency, oxygenation, normocapnic ventilation, and adequate cerebral perfusion pressure (CPP) are key to preserving collateral blood flow. Hypotension, hypoxia, hyperthermia, hypoglycemia and hyperglycemia must be avoided as they accelerate infarct progression. Anesthetic agents play a protective role by reducing cerebral metabolism, although careful monitoring of blood pressure is still necessary to prevent relative hypotension. Thus, the application of neuroanesthetic principles in penumbra–penlucida resuscitation aims to maintain cerebral perfusion, oxygenation, and metabolic stability to prevent the transformation of reversible tissue into a permanent infarct.