BRAIN ABSCESS

DEFINITION

A brain abscess is a collection of infectious material within the tissue of the brain.Bacteria is the most common causative organisms.The most common predisposing factors for abscess among immunocompetant people are ottitis media and sinusitis.

ETIOLOGY

• Ottitis media and sinusitis.
• Intracranial surgery ,penetrating injury or tongue piercing.
• Wound or intra abdominal infection.
• Ottitis media, sinusitis,mastoiditis,dental infections and systemic infections.

 

CLINICAL MANIFESTATIONS

• Head ache usually worse in the morning
• Fever,vomiting and focal neurological deficits.(weakness and decreasing vision reflects the area which is involved)
• Increased ICP and decreased level of consciousness

 

PATHOPHYSIOLOGY

The mechanisms to the entry of the micro organisms are as follows:

• Direct extension-Infections stemming from the sinus,middle ear or mastoid may gain access into the venous drainage of the brain via valveless emissary veins and drain into this region. Because of the antibiotic therapy for this infections incidence rate due to this type of spread has been decreased to a greater extent
• Haematogenous spread-This includes the spread via blood
• Following penetrating head injury or neurosurgery-Most cases can also occur as a result of penetrating head injury or trauma.

 

ASSESSMENT AND DIAGNOSTIC FINDINGS

• History collection and physical examination
• MRI and CT scan demonstrates a ring around the hypodense area.
• Aspiration of the abscess guided by CT scan or mRI helps to identify the organism
• Blood cultures if the origin of the abscess is from a distant sourse
• Chest X-ray to rule out predisposing lung infections
• CT Scan to evaluate the bony structure of the ear and the sinus

 

MEDICAL MANAGEMENT

• The goal of the treatment is to drain the abscess and to provide antibiotic therapy for the infection detected.
• Large IV doses of antibiotics are given to penetrate the blood brain barrier and to reach the site of infection.
• The choice of the antibiotic depends on the causative organism being identified by culture.
• Corticosteroids are prescribed to reduce the inflammatory cerebral edema.
• Antiseizure medications(Phenytoin and phenobarbitone )is prescribed to prevent or to reduce seizure.

 

NURSING MANAGEMENT

• Nursing care focuses on the assessment of neurological status,administering the medication,assessing the response to the treatment and providing supportive care.
• Blood laboratory test results especiallyblood glucose and serum potassium levels has to be monitored and corticosteroids are prescribed.
• Administration of insulin or electrolyte replacement is required to return this values to the normal state.
• The level of consciousness and the physical status has to be monitored constantly
• Observe for neurological deficits like hemiparesis,seizures,visual deficits etc..

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