Bacterial Meningitis Nursing Care and Management: Study Guide

Bacterial meningitis is a medical emergency that can kill within hours. Bacteria inflame the lining around the brain and spinal cord, intracranial pressure climbs in a skull with no room to give, and the patient deteriorates fast. The bedside priorities are early recognition (headache, fever, nuchal rigidity, altered mentation), getting antibiotics in without delay, and protecting the patient from rising ICP and seizures.

What is Bacterial Meningitis?

Meningitis is inflammation of the lining around the brain and spinal cord caused by bacteria or viruses. Bacterial meningitis is the bacterial form. It can be the reason a patient is hospitalized or develop during a hospitalization.

Pathophysiology

Meningeal infection generally starts through the bloodstream or by direct spread.

• Transmission. N. meningitidis concentrates in the nasopharynx and spreads by secretion or aerosol contamination.
• Entry. The organism enters the bloodstream, crosses the blood-brain barrier, and proliferates in the cerebrospinal fluid.
• Stimulation. The host immune response releases cell wall fragments and lipopolysaccharides, driving inflammation of the subarachnoid space and pia mater.
• Increased ICP. With little room for expansion in the cranial vault, inflammation can raise intracranial pressure.
• Circulation. CSF carries inflammatory cellular material from the affected meningeal tissue, which accumulates in the subarachnoid space.

Causes

• Tobacco use. Predisposes the patient to meningitis.
• Viral upper respiratory infection. Increases droplet production.
• Otitis media. Bacteria can cross the epithelial membrane into the subarachnoid space.
• Immune system deficiency. Raises the risk of bacterial meningitis.
• Bacteria. Streptococcus pneumoniae and Neisseria meningitidis cause 80% of cases in adults; Haemophilus influenzae is a major cause in children.

Clinical Manifestations

Headache and fever are usually the first symptoms.

• Headache. Steady or throbbing and very severe from meningeal irritation.
• Neck mobility. A stiff, painful neck is an early sign; head flexion is difficult.
• Positive Kernig's sign. With the thigh flexed on the abdomen, the leg cannot be fully extended.
• Positive Brudzinski's sign. Flexing the neck produces flexion of the knees and hips; passively flexing one lower extremity produces the same movement on the opposite side.
• Photophobia. Extreme light sensitivity is common.
• Skin lesions. Range from a petechial rash with purpuric lesions to large areas of ecchymosis.
• Cognitive impairment. Disorientation and memory loss are common early.
• Seizures. Result from areas of cortical irritability.

Prevention

• Vaccine. The CDC Advisory Committee on Immunization Practices recommends the meningococcal conjugate vaccine for adolescents entering high school and college freshmen living in dormitories.
• Health education. Most states mandate education on meningococcal meningitis.
• Antimicrobial prophylaxis. Close contacts of patients with meningococcal meningitis should receive chemoprophylaxis with rifampin, ciprofloxacin, or ceftriaxone sodium.

Complications

Untreated infection can spread to the eyes (visual impairment), reach the optic nerve (deafness), and irritate the meningeal layers enough to cause seizures.

Assessment and Diagnostic Findings

When the presentation suggests meningitis, testing identifies the causative organism.

• CT or MRI to detect a shift in brain contents (risk of herniation) before a lumbar puncture.
• Bacterial culture and Gram staining of CSF and blood are the key tests.
• Lumbar puncture confirms the diagnosis. The CSF is cloudy. Gram stain reveals organisms in 70% to 80% of cases; when organisms cannot be identified, bacterial antigens can be measured, and H. influenzae is frequently detected this way. Bacterial meningitis shows:
  • Moderately elevated CSF pressures
  • Elevated CSF protein (normal 15 to 45 mg/dl)
  • Decreased CSF glucose (normal 60 to 80 mg/dl, or two thirds of the serum glucose value)
  • Elevated white blood cell count (100 to 10,000/cm3), predominantly polymorphonuclear leukocytes

Medical diagnosis rests on clinical manifestations and is confirmed by isolating the causative organism from the CSF.

Medical Management

Bacterial meningitis is a medical emergency, and prognosis varies with the causative organism. Antibiotics have cut the death rate to less than 5% across all types, but untreated disease can be fatal within hours to days, most often in newborns and older adults. Complications are rare but may include septic shock, vasomotor collapse, seizures, and increased ICP from hydrocephalus, brain swelling, and fluid overload. Residual neurologic deficits are rare in adults.

A unique problem in CNS infection is that an intact blood-brain barrier prevents complete antibiotic penetration. Inflammation disrupts the barrier, so for a short window antibiotics penetrate the CNS. Antibiotics are given intravenously in high doses to reach the CSF, and as inflammation subsides the barrier recovers.

• Maintain adequate fluid and electrolyte balance. Assess neurologic status frequently for early signs of increasing ICP and seizures. Anticonvulsants may be prescribed for seizure prevention.
• Antibiotic therapy. Give early; the drug must cross the blood-brain barrier into the subarachnoid space in enough concentration to halt bacterial multiplication, for example intravenous vancomycin.
• Corticosteroids. Dexamethasone is beneficial as adjunct therapy when given 15 to 20 minutes before the first antibiotic dose and every 6 hours for the next 4 days.
• Fluid volume expanders. Treat dehydration and shock.

Nursing Management

The patient is critically ill, so much of the care is collaborative with the physician, respiratory therapist, and the rest of the team.

Nursing Assessment

• Neurologic status. Assess neurologic status and vital signs continually.
• Pulse oximetry and arterial blood gases. Use these to quickly identify the need for respiratory support.

Nursing Diagnosis

• Risk for infection transmission related to the contagious nature of the organism
• Acute pain related to headache, fever, and neck pain from meningeal irritation
• Acute pain related to nuchal rigidity, muscle aches, immobility, and heightened sensitivity to stimuli
• Impaired physical mobility related to IV infusion, nuchal rigidity, and restraining devices
• Activity intolerance related to fatigue and malaise
• Risk for impaired skin integrity related to immobility, dehydration, and diaphoresis
• Risk for injury related to restlessness and disorientation
• Interrupted family process related to the critical situation and uncertain prognosis
• Anxiety related to treatment and risk of death
• Risk for ineffective therapeutic regimen management

Nursing Care Planning & Goals

Goals are protection against injury, prevention of infection, restoration of normal cognitive function, and prevention of complications.

Nursing Interventions

• Assess neurologic status and vital signs constantly. Determine oxygenation from arterial blood gases and pulse oximetry.
• Insert a cuffed endotracheal tube (or tracheostomy) and place the patient on mechanical ventilation as prescribed.
• Assess blood pressure (usually via arterial line) for incipient shock, which precedes cardiac or respiratory failure.
• Rapid IV fluid replacement may be prescribed, but avoid overhydration because of cerebral edema risk.
• Reduce high fever to cut the oxygen demand load on the heart and brain.
• Protect the patient from injury during seizures or altered level of consciousness.
• Monitor daily weight, serum electrolytes, and urine volume, specific gravity, and osmolality, especially if SIADH is suspected.
• Prevent immobility complications such as pressure ulcers and pneumonia.
• Institute infection control precautions until 24 hours after antibiotics begin (oral and nasal discharge is infectious).
• Keep the family informed and allow visits at appropriate intervals.

Evaluation

Confirm avoidance of injury and infection, restored cognitive function, and prevention of complications.

Discharge and Home Care Guidelines

At home, the patient should alternate rest and activity to conserve energy, eat safe and healthy foods, follow simple infection control measures, and report signs of an infectious process to the physician promptly.

Documentation Guidelines

Document the patient's response to and acceptable level of pain, prior medication use, current physical findings, understanding of individual risks and safety concerns, available resources, current and previous function, effect on independence and lifestyle, laboratory and diagnostic results, mental status or cognitive evaluation, the plan of care and teaching plan, response to interventions, progress toward outcomes, and plan modifications.