What should the Acute Care Gerontological Nurse Practitioner (AGACNP) order for a patient with suspected Guillain-Barré Syndrome (GBS) presenting with progressive lower extremity weakness and reduced deep tendon reflexes?

Management of Suspected Guillain-Barré Syndrome

The AGACNP should order vital capacity measurement as the most critical initial step for this patient with suspected Guillain-Barré Syndrome presenting with progressive ascending weakness following a viral illness. 1

Clinical Assessment and Diagnosis

• The patient's presentation strongly suggests Guillain-Barré Syndrome (GBS) with characteristic features of:
  • Recent viral illness (2 weeks prior) 1
  • Progressive ascending weakness (feet to knees to hips) 1
  • Reduced deep tendon reflexes (Achilles and patellar) 1
  • Neck and back pain 2

Immediate Management Priorities

Respiratory Assessment

• Vital capacity measurement is essential as respiratory failure is a life-threatening complication of GBS that requires immediate intervention 1
• The "20/30/40 rule" should be applied: patient is at risk of respiratory failure if vital capacity <20 ml/kg, maximum inspiratory pressure <30 cmH₂O, or maximum expiratory pressure <40 cmH₂O 1, 3
• Regular monitoring of respiratory function is crucial as up to 22% of GBS patients require mechanical ventilation within the first week of admission 1
• Additional respiratory assessments should include:
  • Use of accessory respiratory muscles 1
  • Single breath count (≤19 predicts need for mechanical ventilation) 1
  • Arterial blood gas measurements if respiratory compromise is suspected 1

ICU Admission Criteria

• Patients should be admitted to the ICU for:
  • Evolving respiratory distress with imminent respiratory insufficiency 1
  • Severe autonomic cardiovascular dysfunction 1
  • Severe swallowing dysfunction or diminished cough reflex 1
  • Rapid progression of weakness 1

Treatment Approach

• After establishing respiratory status, immunomodulatory therapy should be initiated:
  • Intravenous immunoglobulin (IVIg) at 0.4 g/kg body weight daily for 5 days is the first-line treatment 1, 3
  • Plasma exchange (200-250 ml plasma/kg body weight in five sessions) is an equally effective alternative 1, 3
  • Treatment should be initiated as early as possible in the disease course 3
• Corticosteroids alone are not recommended for GBS treatment as they have shown no significant benefit and may even have negative effects 1, 2

Ongoing Monitoring

• Regular assessment of muscle strength in neck, arms, and legs using the Medical Research Council grading scale 1
• Functional disability assessment using the GBS disability scale 1
• Monitoring for swallowing and coughing difficulties to prevent aspiration 1, 4
• Assessment of autonomic dysfunction via ECG, heart rate, blood pressure, and bowel/bladder function 1

Potential Complications to Monitor

• Cardiovascular and respiratory dysfunction (cause up to two-thirds of deaths in GBS) 1, 3
• Pain, hallucinations, anxiety, and depression 1
• Hospital-acquired infections, pressure ulcers, and deep vein thrombosis 1
• Treatment-related fluctuations (occur in 6-10% of patients within 2 months of initial improvement) 4, 5

Why Not Other Options

• Glucocorticoids (Option A): Not recommended as first-line therapy as they have shown no significant benefit and may have negative effects on outcomes 1, 2
• Physical therapy (Option B): Important for rehabilitation but not the immediate priority for a patient with rapidly progressive weakness who can't stand 1
• Antiviral therapy (Option D): Not indicated as the preceding infection has usually resolved before the onset of GBS symptoms 1

Pitfalls and Caveats

• Respiratory failure can develop rapidly, often without obvious clinical signs of dyspnea 1, 6
• The Erasmus GBS Respiratory Insufficiency Score (EGRIS) can help identify patients at risk of requiring ventilation 1
• Avoid medications that can worsen neuromuscular function, such as β-blockers, IV magnesium, fluoroquinolones, aminoglycosides, and macrolides 2
• About 5% of patients initially diagnosed with GBS may later be diagnosed with acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) if repeated relapses occur 5, 7