What is the immediate treatment for a patient diagnosed with Guillain-Barré Syndrome (GBS)?

Immediate Treatment for Guillain-Barré Syndrome

Admit the patient immediately to an inpatient unit with capability for rapid transfer to ICU-level monitoring and initiate intravenous immunoglobulin (IVIg) at 0.4 g/kg/day for 5 consecutive days (total dose 2 g/kg) if the patient is unable to walk unaided and within 2 weeks of symptom onset. 1, 2, 3

Initial Management Steps

Immediate Admission and Monitoring

• Admit to a monitored unit with rapid ICU transfer capability because GBS can progress rapidly to respiratory failure, which occurs in approximately 25% of patients 1, 2
• Obtain immediate neurology consultation to confirm diagnosis and guide treatment 1, 3
• Begin frequent respiratory function monitoring using vital capacity (VC), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) 1, 2
• Apply the "20/30/40 rule" to assess respiratory failure risk: patient is at risk if VC <20 mL/kg, MIP <30 cmH₂O, or MEP <40 cmH₂O 2

Diagnostic Workup (Concurrent with Treatment Initiation)

• Perform MRI of spine with and without contrast to rule out compressive lesions and evaluate for nerve root enhancement 4, 1
• Conduct lumbar puncture for CSF analysis, which typically shows elevated protein (though CSF may also show elevated WBCs in immune checkpoint inhibitor-related cases) 4, 1
• Order electrodiagnostic studies (nerve conduction studies and EMG) to evaluate polyneuropathy 1, 3
• Consider anti-ganglioside antibody testing, particularly anti-GQ1b if Miller Fisher syndrome is suspected 4, 3

First-Line Treatment

IVIg Administration

IVIg is the preferred first-line treatment over plasma exchange due to easier administration, wider availability, and higher completion rates 2, 3, 5

• Dosing: 0.4 g/kg/day for 5 consecutive days (total 2 g/kg) 1, 2, 3
• Timing: Initiate within 2 weeks of symptom onset for patients unable to walk unaided 2, 3
• The 5-day regimen is preferred over shorter regimens because treatment-related fluctuations occur more frequently with abbreviated courses 1

Alternative: Plasma Exchange

• Plasma exchange (12-15 L over 4-5 exchanges in 1-2 weeks) is equally effective as IVIg but less commonly used due to practical considerations 2, 3, 5
• Can be initiated within 4 weeks of symptom onset in patients unable to walk unaided 3

Critical Monitoring During Treatment

Neurological Assessment

• Perform frequent neurological examinations to track disease progression 1, 2
• Monitor for autonomic dysfunction via electrocardiography, heart rate, blood pressure, and bowel/bladder function 1, 2
• Assess for pain and provide nonopioid management of neuropathic pain 4

Respiratory Monitoring

• Use the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to calculate probability of requiring mechanical ventilation 2, 3
• Perform frequent pulmonary function assessments 4

Important Treatment Caveats

What NOT to Do

• Do not give corticosteroids alone as they are ineffective and may worsen outcomes 2, 3
• Do not routinely give a second course of IVIg to patients with poor prognosis, as this increases serious adverse events (including thromboembolic complications) without proven benefit 2, 6
• Do not combine PE followed immediately by IVIg as this does not confer significant extra benefit 3, 5
• Avoid medications that worsen neuromuscular function: β-blockers, IV magnesium, fluoroquinolones, aminoglycosides, and macrolides 4, 2

Special Considerations

• In immune checkpoint inhibitor-related GBS, permanently discontinue the causative agent and consider concurrent corticosteroids (methylprednisolone 2-4 mg/kg/day) with IVIg or plasma exchange 4, 2
• In children, IVIg is strongly preferred over plasma exchange due to better tolerability 2
• In pregnant women, IVIg is preferred over plasma exchange due to fewer monitoring requirements 2

Expected Course and Prognosis

• Approximately 40% of patients do not improve in the first 4 weeks following treatment, which does not necessarily indicate treatment failure 2
• Treatment-related fluctuations (TRFs) occur in 6-10% of patients within 2 months of initial improvement; repeating the full IVIg course is common practice for TRFs 2
• About 80% of patients regain walking ability at 6 months, though 20% remain unable to walk 2, 3
• Mortality is 3-10%, most commonly from cardiovascular and respiratory complications 1, 2
• Consider changing diagnosis to acute-onset CIDP if progression continues beyond 8 weeks from onset (occurs in ~5% of cases) 3