coma昏迷.ppt

MANAGEMENT AND EVALUATION OF THE COMATOSE PATIENT OBJECTIVES Primary Objective: The physician should be able to stabilize, evaluate, and treat the comatose patient in the emergent setting. The physician should understand this involves an organized, sequential, prioritized approach. The Comatose PatientPrimary Objectives Airway Breathing Circulation Treatment of rapidly progressive, dangerous metabolic causes of coma (hypoglycemia) Evaluation as to whether there is significant increased ICP or mass lesions. Treatment of ICP to temporize until surgical intervention is possible. The Comatose PatientSecondary Objectives The physician should understand and recognize: Coma Herniation syndromes Signs of supratentorial mass lesions Signs of subtentorial mass lesions The physician should be able to develop the differential diagnosis of metabolic coma. The Comatose PatientNeurophysiology Consciousness requires: An intact pontine reticular activating system An intact cerebral hemisphere, or at least part of a hemisphere Coma requires dysfunction of either the: Pontine reticular activating system, or Bihemispheric cerebral dysfunction The Comatose PatientClassifications Supratentorial lesions cause coma by either widespread bilateral disease, increased intracranial pressure, or herniation. Infratentorial lesions involve the RAS, usually with associated brainstem signs Metabolic coma causes diffuse hemispheric involvement and depression of RAS, usually without focal findings Psychogenic Supratentorial Mass Lesions Hematoma Neoplasm Abscess Contusion Vascular Accidents Diffuse Axonal Damage Supratentorial Mass LesionsPathophysiology Altered consciousness is based on Increased intracranial pressure Herniation Diffuse bilateral lesions Infratentorial Lesions Cause coma by affecting reticular activating system in pons Brainstem nuclei and tracts usually involved with resultant focal brainstem findings Infratentorial LesionsCauses of Coma Neoplasm Vascular accidents Trau