The Acutely Comatose Patient
The Acutely Comatose Patient
A patient's acute and persistent unresponsiveness in the emergency department often triggers a neurology consultation. Given the many potential causes of unresponsiveness, the initial objective of the neurologist should be a comprehensive history and physical examination, which should allow localization of the lesion, if possible, and an initial narrowing of the differential diagnosis. In addition, neuroimaging review and laboratory evaluation have come to play an increasingly important role in identification of the potential causes of unresponsiveness. However, in some instances, the computed tomography or the magnetic resonance imaging scans are normal and sorting out the cause and depth of unresponsiveness requires clinical skill. The neurologist is adept at correctly moving through a differential diagnosis and this has a profound effect on management. Once appropriate treatment has been initiated, the outcome can be assessed. Recovery from coma can be prolonged, but is less likely if early involvement of the brainstem is apparent.
A significant injury or dysfunction of the brain is needed to produce unresponsiveness. The top three causes of coma outside the hospital remain intoxication (including illicit and legal drugs), diabetic dysregulation, and traumatic head injury. The distribution of causes of unresponsiveness, however, is different in the emergency department, the critical care unit, the surgical recovery room, or the general hospital ward. In general, the management priority in any case of unresponsiveness should be to prevent a treatable cause of coma from leading to a permanent injury.
Within the emergency department, the approach to coma is to stabilize (more than airway, breathing, circulation [ABCs]), to diagnose (more than the Glasgow Coma Scale), to manage (more than intravenous glucose and antidotes), and to critically assess information one step at a time (more than an algorithm).
Abstract and Introduction
Abstract
A patient's acute and persistent unresponsiveness in the emergency department often triggers a neurology consultation. Given the many potential causes of unresponsiveness, the initial objective of the neurologist should be a comprehensive history and physical examination, which should allow localization of the lesion, if possible, and an initial narrowing of the differential diagnosis. In addition, neuroimaging review and laboratory evaluation have come to play an increasingly important role in identification of the potential causes of unresponsiveness. However, in some instances, the computed tomography or the magnetic resonance imaging scans are normal and sorting out the cause and depth of unresponsiveness requires clinical skill. The neurologist is adept at correctly moving through a differential diagnosis and this has a profound effect on management. Once appropriate treatment has been initiated, the outcome can be assessed. Recovery from coma can be prolonged, but is less likely if early involvement of the brainstem is apparent.
Introduction
A significant injury or dysfunction of the brain is needed to produce unresponsiveness. The top three causes of coma outside the hospital remain intoxication (including illicit and legal drugs), diabetic dysregulation, and traumatic head injury. The distribution of causes of unresponsiveness, however, is different in the emergency department, the critical care unit, the surgical recovery room, or the general hospital ward. In general, the management priority in any case of unresponsiveness should be to prevent a treatable cause of coma from leading to a permanent injury.
Within the emergency department, the approach to coma is to stabilize (more than airway, breathing, circulation [ABCs]), to diagnose (more than the Glasgow Coma Scale), to manage (more than intravenous glucose and antidotes), and to critically assess information one step at a time (more than an algorithm).
