unarousable

Unarousable is a clinical term used to describe a state in which a person cannot be awakened by any external stimuli, including voice, touch, or painful stimulation. It typically denotes a coma or coma-like condition where the patient has no purposeful response to stimuli and lacks observable awareness. While individuals who are unarousable may exhibit reflexes or autonomic activity, they do not demonstrate purposeful movement or communication.

Unarousable states arise from severe disturbance of the brain systems responsible for wakefulness, notably the reticular activating system in the brainstem and its connections to the cortex. Causes are variable and may include traumatic brain injury, hypoxic or ischemic brain injury, intracranial hemorrhage, large strokes, infections such as encephalitis, metabolic derangements (for example, severe electrolyte or fluid disturbances, organ failure), drug or toxin effects, and post-anoxic coma.

Distinctions: An unarousable patient may be in a coma, but not all coma patients are unarousable at all times. Those in a vegetative state or minimally conscious state may have spontaneous arousal or eye-opening but lack awareness. Arousability is a key clinical criterion in differentiating levels of consciousness.

Assessment and prognosis: Evaluation includes neurological examination, imaging (CT or MRI), EEG, and laboratory studies to identify reversible causes. The Glasgow Coma Scale may be limited when a patient is truly unarousable. Prognosis is highly dependent on etiology, duration of the unarousable state, age, and comorbidities; some patients recover partial consciousness, while others do not.

Management: Immediate priorities are airway protection, breathing support, circulation stabilization, and treatment of the underlying cause. In suspected trauma, spinal precautions and intensive care are common. Decisions about continuing life-sustaining measures depend on the cause, trajectory, and overall prognosis.