Guillain-Barré Syndrome (GBS)¶

VERSION: 1.0 CREATED: January 27, 2026 STATUS: Approved

DIAGNOSIS: Guillain-Barré Syndrome (GBS)

ICD-10: G61.0 (Guillain-Barré syndrome)

CPT CODES: 85025 (CBC with differential), 80053 (CMP (BMP + LFTs)), 83735 (Magnesium), 84100 (Phosphorus), 85652 (ESR), 82947 (Blood glucose), 81003 (Urinalysis), 85610 (PT/INR), 86900 (Type and screen), 86255 (Anti-ganglioside antibodies (GM1, GD1a, GD1b, GQ1b)), 80074 (Hepatitis B surface antigen, anti-HBc), 87389 (HIV 1/2 antigen/antibody), 84443 (TSH), 82607 (B12), 86334 (Serum protein electrophoresis (SPEP) with immunofixation), 72156 (MRI spine with and without contrast (whole spine)), 95907-95913 (Nerve conduction studies), 71046 (Chest X-ray), 93000 (ECG (12-lead)), 70553 (MRI brain with and without contrast), 71260 (CT chest with contrast), 93306 (Echocardiogram), 94010 (Pulmonary function testing (formal)), 89051 (Cell count (tubes 1 and 4)), 84157 (Protein), 82945 (Glucose with serum glucose), 88104 (Cytology), 86592 (VDRL (CSF)), 83916 (Oligoclonal bands), 96365 (IVIG (intravenous immunoglobulin)), 36514 (Plasmapheresis (PLEX))

SYNONYMS: Guillain-Barré syndrome, GBS, acute inflammatory demyelinating polyneuropathy, AIDP, acute motor axonal neuropathy, AMAN, acute motor-sensory axonal neuropathy, AMSAN, ascending paralysis, Landry's paralysis, post-infectious polyneuropathy

SCOPE: Acute inflammatory polyradiculoneuropathy including AIDP, AMAN, AMSAN, and Miller Fisher syndrome (MFS) variants. Covers acute diagnosis, respiratory monitoring, immunotherapy (IVIG/PLEX), autonomic dysfunction management, pain control, and rehabilitation planning. Excludes CIDP (chronic inflammatory demyelinating polyneuropathy — separate template), tick paralysis, and chronic neuropathies.

PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

═══════════════════════════════════════════════════════════════ SECTION A: ACTION ITEMS ═══════════════════════════════════════════════════════════════

1. LABORATORY WORKUP¶

1A. Essential/Core Labs¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CBC with differential (CPT 85025)	STAT	STAT	ROUTINE	STAT	Baseline; infection screen; exclude hematologic causes	Normal; leukocytosis suggests infection trigger
CMP (BMP + LFTs) (CPT 80053)	STAT	STAT	ROUTINE	STAT	Electrolyte abnormalities (hyponatremia from SIADH), renal/hepatic function for IVIG dosing	Normal
Magnesium (CPT 83735)	STAT	STAT	ROUTINE	STAT	Hypomagnesemia worsens weakness; arrhythmia risk	>1.8 mg/dL
Phosphorus (CPT 84100)	STAT	ROUTINE	ROUTINE	STAT	Hypophosphatemia causes weakness (mimic)	>2.5 mg/dL
ESR (CPT 85652) / CRP (CPT 86140)	URGENT	ROUTINE	ROUTINE	URGENT	Inflammatory markers; infection screen	Mildly elevated (non-specific)
Blood glucose (CPT 82947)	STAT	STAT	ROUTINE	STAT	Diabetes as comorbidity; hyperglycemia management	Normal
Urinalysis (CPT 81003)	STAT	ROUTINE	ROUTINE	STAT	UTI as precipitant; baseline	Normal
Pregnancy test (β-hCG)	STAT	STAT	ROUTINE	STAT	Affects IVIG formulation choice; imaging considerations	Document result
PT/INR (CPT 85610), aPTT (CPT 85730)	STAT	ROUTINE	-	STAT	Coagulation status before procedures (LP, central line)	Normal
Type and screen (CPT 86900)	STAT	ROUTINE	-	STAT	Potential need for PLEX	On file

1B. Extended Workup (Second-line)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
Anti-ganglioside antibodies (GM1, GD1a, GD1b, GQ1b) (CPT 86255)	-	ROUTINE	ROUTINE	ROUTINE	GM1: AMAN; GQ1b: Miller Fisher; GD1a: AMAN; helps confirm diagnosis and subtype	Positive supports diagnosis (negative does not exclude)
Anti-GQ1b antibody	-	ROUTINE	ROUTINE	-	Miller Fisher syndrome (ataxia, ophthalmoplegia, areflexia)	Positive in >90% MFS
Campylobacter jejuni serology (IgM, IgG)	-	ROUTINE	ROUTINE	-	Most common infectious trigger (30%); AMAN variant association	Positive IgM suggests recent infection
Mycoplasma pneumoniae IgM	-	ROUTINE	ROUTINE	-	Common triggering infection	Positive IgM suggests recent infection
CMV IgM	-	ROUTINE	ROUTINE	-	Triggering infection; associated with severe demyelinating GBS	Positive IgM
EBV panel (VCA IgM, EBNA)	-	ROUTINE	ROUTINE	-	Triggering infection	Positive VCA IgM
Hepatitis B surface antigen, anti-HBc (CPT 80074)	-	ROUTINE	ROUTINE	-	Screen before IVIG; reactivation risk	Negative
Hepatitis C antibody (CPT 80074)	-	ROUTINE	ROUTINE	-	Cryoglobulinemia-associated neuropathy (differential)	Negative
HIV 1/2 antigen/antibody (CPT 87389)	-	ROUTINE	ROUTINE	-	HIV-associated neuropathy; acute HIV can mimic GBS	Negative
TSH (CPT 84443)	-	ROUTINE	ROUTINE	-	Thyroid dysfunction can cause weakness	Normal
B12 (CPT 82607), methylmalonic acid (CPT 83921)	-	ROUTINE	ROUTINE	-	B12 deficiency neuropathy (differential)	Normal
Serum protein electrophoresis (SPEP) with immunofixation (CPT 86334)	-	ROUTINE	ROUTINE	-	Paraproteinemia-associated neuropathy (differential); POEMS	Normal
IgA level (quantitative)	-	ROUTINE	-	ROUTINE	IgA deficiency contraindicates standard IVIG (anaphylaxis risk); check BEFORE IVIG if possible	Normal (>7 mg/dL)

1C. Rare/Specialized (Refractory or Atypical)¶

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
Zika virus serology/PCR	-	EXT	EXT	-	Endemic areas; associated with GBS outbreaks	Negative
Influenza A/B PCR	-	EXT	-	EXT	Triggering infection; seasonal	Negative
COVID-19 PCR/antigen	-	ROUTINE	-	ROUTINE	Post-COVID GBS association reported	Document result
Lyme serology (ELISA, Western blot)	-	EXT	EXT	-	Lyme-associated polyradiculopathy (differential); endemic areas	Negative
Paraneoplastic panel (serum) (CPT 86255)	-	EXT	EXT	-	If atypical features or poor response to treatment	Negative
Heavy metals (lead, arsenic, thallium)	-	EXT	EXT	-	Toxic neuropathy mimic; occupational exposure	Normal
Porphyrins (urine ALA, PBG)	-	EXT	EXT	-	Acute intermittent porphyria mimic (motor predominant, autonomic dysfunction)	Normal
Anti-MAG antibody (CPT 86255)	-	EXT	EXT	-	MAG-associated neuropathy (differential; chronic presentation)	Negative

2. DIAGNOSTIC IMAGING & STUDIES¶

2A. Essential/First-line¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
MRI spine with and without contrast (whole spine) (CPT 72156)	URGENT	URGENT	ROUTINE	URGENT	Within 24h of presentation	Nerve root enhancement (anterior roots in AIDP); exclude compressive myelopathy, spinal cord lesion, epidural abscess	Pacemaker, metallic implants
Nerve conduction studies (CPT 95907-95913) / EMG (CPT 95886) (NCS/EMG)	-	URGENT	ROUTINE	URGENT	Ideally within 3-5 days of symptom onset (may be normal in first 48h); repeat at 2-3 weeks if initially non-diagnostic	Demyelinating pattern: prolonged distal latencies, conduction block, temporal dispersion, prolonged F-waves, absent H-reflex. Axonal pattern (AMAN): reduced CMAP amplitudes with normal velocities	None significant; avoid anticoagulated patients for EMG needle exam
Chest X-ray (CPT 71046)	URGENT	ROUTINE	-	URGENT	On admission	Aspiration, atelectasis, baseline for ventilator management	None significant
ECG (12-lead) (CPT 93000)	URGENT	ROUTINE	-	URGENT	On admission and PRN	Arrhythmias (sinus tachycardia, bradycardia, AV block); autonomic dysfunction	None

2B. Extended¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
MRI brain with and without contrast (CPT 70553)	-	ROUTINE	ROUTINE	ROUTINE	If Miller Fisher variant suspected or cranial nerve involvement	Cranial nerve enhancement (especially CN III, VI, VII); exclude central lesion	Same as MRI
CT chest with contrast (CPT 71260)	-	EXT	EXT	-	If paraneoplastic etiology suspected; thymoma screen if MG in differential	Mass lesion	Contrast allergy, renal impairment
Repeat NCS/EMG	-	ROUTINE	ROUTINE	-	At 2-4 weeks if initial study non-diagnostic or to assess prognosis	Evolution of findings; axonal degeneration predicts slower recovery	Same as initial
Echocardiogram (CPT 93306)	-	ROUTINE	-	ROUTINE	If autonomic instability or new murmur	Cardiac function; Takotsubo in severe autonomic GBS	None significant

2C. Rare/Specialized¶

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Nerve ultrasound (high-resolution)	-	EXT	EXT	-	If diagnosis uncertain	Nerve enlargement in CIDP (helps differentiate); some enlargement reported in GBS	None
Pulmonary function testing (formal) (CPT 94010)	-	ROUTINE	ROUTINE	-	If borderline respiratory function	Full spirometry for outpatient monitoring	Unable to cooperate

LUMBAR PUNCTURE¶

Indication: Diagnostic confirmation of GBS; albuminocytologic dissociation is classic finding

Timing: URGENT in ED or within first 24h of admission; may be normal in first 48h — repeat at 1 week if initially normal

Volume Required: 10-15 mL (standard diagnostic)

Study	ED	HOSP	OPD	Rationale	Target Finding
Opening pressure	URGENT	ROUTINE	ROUTINE	Rule out elevated ICP	10-20 cm H2O (normal)
Cell count (tubes 1 and 4) (CPT 89051)	URGENT	ROUTINE	ROUTINE	Albuminocytologic dissociation	WBC <10 cells/µL (if >50 WBC, reconsider diagnosis — HIV, Lyme, sarcoidosis, lymphoma)
Protein (CPT 84157)	URGENT	ROUTINE	ROUTINE	Classic finding: elevated protein with normal WBC	Elevated >45 mg/dL (often >100 mg/dL; may be normal in first week)
Glucose with serum glucose (CPT 82945)	URGENT	ROUTINE	ROUTINE	Normal in GBS; low in infectious/malignant meningitis	Normal (>60% serum)
Gram stain and culture	URGENT	ROUTINE	ROUTINE	Exclude bacterial meningitis	No organisms
Cytology (CPT 88104)	-	ROUTINE	ROUTINE	Exclude leptomeningeal lymphoma/carcinomatosis	Negative
VDRL (CSF) (CPT 86592)	-	ROUTINE	ROUTINE	Neurosyphilis can mimic	Negative
Oligoclonal bands (CPT 83916), IgG index	-	ROUTINE	ROUTINE	Differentiate from MS; may be positive in GBS (non-specific)	Negative or low titer

Special Handling: Standard processing. Cell count and protein are the critical values.

Contraindications: Elevated ICP without imaging (CT first), coagulopathy (INR >1.5, platelets <50K), skin infection at LP site. Anticoagulation should be held.

3. TREATMENT¶

3A. Acute/Emergent¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
IVIG (intravenous immunoglobulin) (CPT 96365)	IV	-	0.4 g/kg :: IV :: daily x 5 days :: 0.4 g/kg/day IV x 5 days (total 2 g/kg); infuse over 4-8h per dose; slow initial rate and increase per protocol. Start within 2 weeks of symptom onset for maximum benefit	IgA deficiency (use IgA-depleted product); acute renal failure; anaphylaxis to immunoglobulin	Vital signs q15min during first infusion, then q30min; renal function (BUN, Cr) before and during; headache (aseptic meningitis); thrombotic events; hemolysis (haptoglobin, LDH, direct Coombs if symptoms)	-	STAT	-	STAT
Plasmapheresis (PLEX) (CPT 36514)	-	-	N/A :: - :: once :: 5 exchanges over 7-14 days (typically every other day); each exchange 1-1.5 plasma volumes; use albumin replacement. Start within 4 weeks of symptom onset	Hemodynamic instability, severe sepsis, active bleeding, heparin allergy (for circuit anticoagulation), poor vascular access	BP and HR continuous during exchange; calcium (citrate toxicity: tingling, cramping); fibrinogen; CBC; electrolytes; line site infection	-	STAT	-	STAT
Intubation and mechanical ventilation	-	-	20 mL/kg :: - :: - :: Indications (20/30/40 rule): FVC <20 mL/kg, NIF weaker than -30 cmH2O, >30% decline in FVC from baseline, or clinical respiratory distress. Use non-depolarizing agents (avoid succinylcholine — hyperkalemia risk). RSI with rocuronium preferred	N/A (life-saving)	Ventilator settings per ICU protocol; sedation; daily spontaneous breathing trial when improving	STAT	STAT	-	STAT
DVT prophylaxis: Enoxaparin	SC	-	40 mg :: SC :: daily :: 40 mg SC daily; start on admission	Active bleeding, platelets <50K, CrCl <30 (use UFH)	Platelets q3 days; anti-Xa if renal impairment	-	ROUTINE	-	ROUTINE
DVT prophylaxis: Heparin SC (alternative)	SC	-	5000 units :: SC :: - :: 5000 units SC q8-12h	Active bleeding, HIT	Platelets q3 days	-	ROUTINE	-	ROUTINE
Pneumatic compression devices	-	-	N/A :: - :: continuous :: Apply bilaterally on admission; continue until ambulatory	Acute DVT, severe PVD	Skin checks daily	STAT	STAT	-	STAT

3B. Symptomatic Treatments¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Gabapentin	PO	Neuropathic pain (very common in GBS — 55-89%)	300 mg :: PO :: qHS :: Start 300 mg PO qHS; increase by 300 mg/day every 1-3 days; target 900-1800 mg TID; max 3600 mg/day	Severe renal impairment (dose adjust); oversedation	Sedation, dizziness; adjust for renal function	-	ROUTINE	ROUTINE	ROUTINE
Pregabalin	PO	Neuropathic pain (alternative)	75 mg :: PO :: BID :: Start 75 mg PO BID; increase to 150 mg BID after 3-7 days; max 300 mg BID	Renal impairment (dose adjust)	Sedation, weight gain, peripheral edema	-	ROUTINE	ROUTINE	ROUTINE
Carbamazepine	PO	Neuropathic pain (alternative)	100 mg :: PO :: BID :: Start 100 mg PO BID; increase by 100 mg/day q3-7 days; target 400-800 mg/day in divided doses; max 1200 mg/day	AV block, bone marrow suppression, HLA-B*1502 (Asian descent — screen before starting)	CBC, LFTs, sodium at baseline and 2-4 weeks; drug level	-	ROUTINE	ROUTINE	-
Amitriptyline	PO	Neuropathic pain, insomnia	10-25 mg :: PO :: qHS :: Start 10-25 mg PO qHS; increase by 10-25 mg q1-2 weeks; max 150 mg/day	Arrhythmia, urinary retention, angle-closure glaucoma, recent MI	ECG if cardiac risk; anticholinergic side effects	-	ROUTINE	ROUTINE	-
Acetaminophen	PO	Musculoskeletal pain, headache	650-1000 mg :: PO :: q6h :: 650-1000 mg PO q6h; max 4g/day (2g hepatic impairment)	Severe liver disease	LFTs if prolonged	STAT	ROUTINE	ROUTINE	STAT
Morphine IV	IV	Severe pain unresponsive to above	2-4 mg :: IV :: PRN :: 2-4 mg IV q3-4h PRN; use with caution — respiratory depression risk especially with respiratory compromise	Respiratory failure (relative — monitor closely), ileus	RR, SpO2, sedation scale; bowel function	-	URGENT	-	URGENT
Oxycodone	PO	Moderate-severe pain (if able to swallow)	5-10 mg :: PO :: PRN :: 5-10 mg PO q4-6h PRN	Same as morphine	Same as morphine	-	ROUTINE	ROUTINE	-
Metoclopramide	IV	Gastroparesis, nausea (autonomic dysfunction)	10 mg :: IV :: q6h :: 10 mg IV/PO q6h PRN; max 40 mg/day; limit duration to <12 weeks	Seizure history, Parkinson disease, GI obstruction	Tardive dyskinesia with prolonged use	-	ROUTINE	-	ROUTINE
Docusate sodium	PO	Constipation (immobility + opioids)	100 mg :: PO :: BID :: 100 mg PO BID	GI obstruction	Bowel function	-	ROUTINE	ROUTINE	ROUTINE
Senna	PO	Constipation	8.6-17.2 mg :: PO :: qHS :: 8.6-17.2 mg PO qHS	GI obstruction	Bowel function	-	ROUTINE	ROUTINE	-
Polyethylene glycol (MiraLAX)	PO	Constipation (if docusate insufficient)	17 g :: PO :: daily :: 17 g PO daily in 8 oz water	GI obstruction	Bowel function	-	ROUTINE	ROUTINE	-
Melatonin	PO	Insomnia (ICU delirium prevention)	3-5 mg :: PO :: qHS :: 3-5 mg PO qHS	None significant	Sleep quality	-	ROUTINE	-	ROUTINE
Lorazepam	IV	Anxiety, autonomic crisis	0.5-1 mg :: IV :: PRN :: 0.5-1 mg IV/PO q6-8h PRN	Respiratory compromise (use with extreme caution)	RR, sedation	-	URGENT	-	URGENT

3C. Second-line/Refractory¶

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Second course IVIG	PO	-	0.4 g/kg :: PO :: daily x 5 days :: 0.4 g/kg/day x 5 days; consider if progressive deterioration after initial treatment or treatment-related fluctuation (TRF)	Same as initial IVIG	Same as initial IVIG	-	URGENT	-	URGENT
PLEX after IVIG failure	-	-	N/A :: - :: per protocol :: 5 exchanges over 7-14 days; wait ≥2 weeks after IVIG to avoid washing out immunoglobulin	Same as initial PLEX	Same as initial PLEX	-	URGENT	-	URGENT
IV methylprednisolone (NOT standard of care) (CPT 96365)	IV	-	500 mg :: IV :: daily :: 500 mg IV daily x 5 days; evidence does NOT support steroids alone; may be considered in combination with IVIG per some centers for refractory cases	Active infection, uncontrolled diabetes	Glucose, BP, GI prophylaxis	-	EXT	-	EXT

3D. Disease-Modifying or Chronic Therapies¶

Not applicable for GBS (acute monophasic illness). If recurrent or chronic course (>8 weeks), reconsider diagnosis — evaluate for CIDP.

4. OTHER RECOMMENDATIONS¶

4A. Referrals & Consults¶

Recommendation	ED	HOSP	OPD	ICU	Indication
Neurology consultation	STAT	STAT	-	STAT	All suspected GBS; diagnostic confirmation, treatment initiation
Pulmonology / Critical care	URGENT	URGENT	-	STAT	Declining respiratory function; intubation decision; ventilator management
Physical therapy (PT)	-	URGENT	ROUTINE	URGENT	Early passive ROM to prevent contractures; gradual mobilization as tolerated; gait training
Occupational therapy (OT)	-	URGENT	ROUTINE	URGENT	Upper extremity function, ADLs, adaptive equipment
Speech-language pathology (SLP)	-	URGENT	ROUTINE	URGENT	Dysphagia evaluation (bulbar weakness); aspiration prevention
Rehabilitation medicine (physiatry)	-	ROUTINE	ROUTINE	-	Rehabilitation planning; disposition (inpatient rehab vs SNF)
Pain management	-	ROUTINE	ROUTINE	ROUTINE	Refractory neuropathic pain
Social work	-	ROUTINE	ROUTINE	-	Discharge planning, family support, financial resources
Psychology / Psychiatry	-	ROUTINE	ROUTINE	-	Anxiety, depression, PTSD (common in ICU patients)
Respiratory therapy	-	STAT	-	STAT	Bedside spirometry (FVC, NIF); pulmonary toilet; ventilator weaning
Nutrition / Dietitian	-	ROUTINE	-	ROUTINE	Enteral feeding plan if intubated; caloric needs during recovery
Infectious disease	-	ROUTINE	-	-	If triggering infection unclear or atypical presentation

4B. Patient Instructions¶

Recommendation	ED	HOSP	OPD
Return to ED / Call 911 if: increasing difficulty breathing, new swallowing difficulty, rapid worsening of weakness, inability to walk, chest pain, or lightheadedness	STAT	STAT	ROUTINE
GBS is typically a self-limited illness; most patients recover substantially but recovery may take months to years	-	ROUTINE	ROUTINE
Do NOT drive until strength and reflexes have recovered and neurology clears	-	ROUTINE	ROUTINE
Comply with physical therapy exercises as prescribed between sessions	-	ROUTINE	ROUTINE
Pain is normal in GBS and will be managed with medications; report if pain is inadequately controlled	-	ROUTINE	ROUTINE
Inform future healthcare providers about GBS history (vaccine considerations, anesthesia precautions)	-	ROUTINE	ROUTINE
Fall prevention: use assistive devices (walker, cane) as recommended; remove tripping hazards at home	-	ROUTINE	ROUTINE
Monitor for signs of blood clots: leg swelling, redness, chest pain, shortness of breath	-	ROUTINE	ROUTINE
Follow-up with neurology in 2-4 weeks after discharge; NCS/EMG may be repeated at 3-6 months	-	ROUTINE	ROUTINE

4C. Lifestyle & Prevention¶

Recommendation	ED	HOSP	OPD
Gradual return to activity as tolerated; avoid overexertion during recovery	-	ROUTINE	ROUTINE
Balanced nutrition for nerve recovery (adequate protein, B vitamins)	-	ROUTINE	ROUTINE
Smoking cessation (impairs nerve healing)	-	ROUTINE	ROUTINE
Adequate sleep (promotes neurologic recovery)	-	ROUTINE	ROUTINE
Mental health support (depression and anxiety common during recovery)	-	ROUTINE	ROUTINE
Flu vaccination: generally safe after GBS; discuss with neurologist (6 weeks post-onset minimum; risk-benefit individualized)	-	-	ROUTINE
COVID-19 vaccination: discuss risk-benefit with neurologist; most experts recommend vaccination after recovery	-	-	ROUTINE

═══════════════════════════════════════════════════════════════ SECTION B: REFERENCE (Expand as Needed) ═══════════════════════════════════════════════════════════════

5. DIFFERENTIAL DIAGNOSIS¶

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Transverse myelitis	Sensory level, upper motor neuron signs (hyperreflexia, Babinski), bladder involvement early, MRI spinal cord lesion	MRI spine (cord signal change); LP (pleocytosis more common); NCS/EMG (normal peripheral nerves)
Myasthenia gravis	Fatigable weakness, ptosis, diplopia, intact reflexes, fluctuating symptoms, no sensory involvement	AChR antibodies, repetitive nerve stimulation (decremental), edrophonium test
Botulism	Descending paralysis (cranial nerves first), pupil involvement, GI prodrome, toxin exposure	Stool/serum botulinum toxin assay; NCS (incremental response at high-rate repetitive stimulation)
Tick paralysis	Ascending paralysis similar to GBS; tick found on exam; rapid recovery after tick removal	Physical exam (search for tick, especially scalp); NCS may show reduced CMAPs; CSF normal
Spinal cord compression	Back pain, sensory level, upper motor neuron signs below level, bladder dysfunction	MRI spine (compressive lesion)
Acute intermittent porphyria	Abdominal pain, psychiatric symptoms, autonomic dysfunction, motor predominant neuropathy, dark urine	Urine ALA and PBG (elevated during attack)
Poliomyelitis / West Nile virus	Asymmetric flaccid paralysis, fever, anterior horn cell pattern, CSF pleocytosis	CSF (elevated WBC); viral PCR; MRI (anterior horn signal)
CIDP	Similar to GBS but progression >8 weeks, relapsing-remitting course, may respond to steroids	NCS/EMG (demyelinating); temporal course >8 weeks; steroid response
Critical illness myopathy/neuropathy	ICU setting, prolonged ventilation, steroid/neuromuscular blocker exposure	NCS/EMG; CK (elevated in myopathy); clinical context
Hypokalemia	Diffuse weakness, cardiac arrhythmia, normal reflexes or hyporeflexia	Serum potassium; ECG; rapid improvement with replacement
Conversion disorder (FND)	Non-physiologic weakness pattern, Hoover sign, give-way weakness, psychiatric history	Normal NCS/EMG; normal LP; clinical exam
Diphtheria	Pharyngeal membrane, palatal weakness, sensorimotor neuropathy weeks after infection	Throat culture; clinical history
HIV-associated neuropathy	Progressive, often sensory predominant; CSF pleocytosis distinguishes from GBS	HIV testing; CSF (WBC >50 suggests HIV, not classic GBS)

6. MONITORING PARAMETERS¶

Parameter	ED	HOSP	OPD	ICU	Frequency	Target/Threshold	Action if Abnormal
Forced Vital Capacity (FVC)	STAT	STAT	ROUTINE	STAT	q4-6h in hospital (q2h if declining); q1-2h in ICU if concerning trend	FVC >20 mL/kg (approximately >1.5L for 75kg adult)	If FVC <20 mL/kg or declining >30% from baseline → elective intubation; transfer to ICU
Negative Inspiratory Force (NIF/MIP)	STAT	STAT	ROUTINE	STAT	q4-6h with FVC	NIF more negative than -30 cmH2O (e.g., -40 is better than -20)	If NIF weaker than -30 cmH2O → prepare for intubation
Peak Cough Flow	-	ROUTINE	-	ROUTINE	q4-6h with FVC	>270 L/min (effective cough)	Airway clearance interventions; suction; assisted cough
Single Breath Count	STAT	STAT	-	STAT	q4h (bedside screening)	Count to ≥20 on single breath	If <10-15 → declining respiratory function, correlate with FVC
Oxygen saturation (SpO2)	STAT	STAT	-	STAT	Continuous in ICU; q4h on floor	≥94%	Late finding — do NOT rely on SpO2 alone; FVC is more sensitive
Blood pressure	STAT	STAT	-	STAT	q4h on floor; continuous in ICU	Stable; watch for lability (autonomic)	If BP lability (swings >20 mmHg): short-acting agents only; avoid long-acting antihypertensives; telemetry
Heart rate and rhythm (telemetry)	STAT	STAT	-	STAT	Continuous x 48h minimum; longer if autonomic symptoms	HR 60-100; sinus rhythm	Bradycardia: atropine ready; Tachycardia: volume, pain control; AV block: consider temporary pacing
Neurologic exam (strength, reflexes)	STAT	STAT	ROUTINE	STAT	q4-8h; Hughes GBS disability scale daily	Stable or improving	Worsening → repeat FVC/NIF; consider additional immunotherapy
Swallowing function	URGENT	STAT	ROUTINE	STAT	Daily assessment; formal SLP if bulbar symptoms	Safe oral intake	NPO if unsafe; NG or PEG for nutrition
Pain assessment (NRS 0-10)	STAT	STAT	ROUTINE	STAT	q4h with vitals	NRS <4	Adjust pain regimen
Bowel function	-	ROUTINE	ROUTINE	ROUTINE	Daily	Regular bowel movements	Bowel program; avoid ileus (autonomic dysfunction)
Bladder function	-	ROUTINE	ROUTINE	ROUTINE	I/O monitoring; post-void residual if needed	Adequate output; PVR <200 mL	Bladder scan; intermittent catheterization if retention
Renal function (BUN, Cr)	-	ROUTINE	-	ROUTINE	Daily during IVIG; q48h otherwise	Stable creatinine	Hold IVIG if rising Cr; hydration
Sodium	-	ROUTINE	-	ROUTINE	Daily	Normal (135-145 mEq/L)	SIADH workup if <130; fluid restriction

7. DISPOSITION CRITERIA¶

Disposition	Criteria
Discharge home	Mild GBS (ambulatory without assistance, Hughes 0-2), stable respiratory function (FVC >60% predicted), adequate pain control on oral medications, safe swallowing, reliable outpatient follow-up, family/caregiver support
Admit to floor (monitored bed preferred)	Any GBS requiring treatment; unable to ambulate independently; FVC 20-30 mL/kg with no downward trend; mild bulbar symptoms; needs IVIG or PLEX
Admit to ICU	FVC <20 mL/kg or declining rapidly; NIF weaker than -30 cmH2O; intubated or imminent intubation; autonomic instability (BP lability, arrhythmia); severe bulbar weakness with aspiration risk; unable to protect airway
Transfer to higher level of care	Need for PLEX not available on-site; need for ICU with neurology expertise; rapidly progressive course
Inpatient rehabilitation	Significant motor deficits (unable to walk independently; Hughes 3-4); able to participate in 3h/day therapy; medically stable
Skilled nursing facility	Unable to tolerate intensive rehabilitation; requires ongoing nursing care; severe deconditioning

8. EVIDENCE & REFERENCES¶

Recommendation	Evidence Level	Source
IVIG 0.4 g/kg/day x 5 days	Class I, Level A	Dutch GBS Study Group, NEJM 1992; Cochrane Review, Hughes 2014
PLEX (5 exchanges) equivalent to IVIG	Class I, Level A	French Cooperative Group, Ann Neurol 1987; North American GBS Study
IVIG + PLEX combination NOT superior to either alone	Class I, Level A	PE/Sandoglobulin GBS Trial Group, Lancet 1997
Corticosteroids alone NOT effective for GBS	Class I, Level A	Cochrane Review, Hughes 2016
IVIG + IV methylprednisolone may shorten recovery (weak evidence)	Class IIb, Level B	Dutch GBS Study Group, Lancet 2004
Bedside FVC and NIF for respiratory monitoring	Class I, Level B	Lawn et al. Arch Neurol 2001
20/30/40 rule for intubation	Class IIa, Level C	Expert consensus; Wijdicks & Borel, Neurology 1998
Avoid succinylcholine in GBS	Class III (Harm)	Risk of hyperkalemia from denervated muscle
Neuropathic pain management (gabapentin, carbamazepine)	Class IIa, Level B	Pandey et al. Anesth Analg 2002; Cochrane Review
Early rehabilitation improves outcomes	Class I, Level B	Khan & Amatya, Eur J Phys Rehabil Med 2012; GBS-CIDP Foundation recommendations
DVT prophylaxis	Class I, Level C	Standard of care for immobilized patients
Anti-ganglioside antibodies (diagnostic, not required)	Class IIa, Level B	Diagnostic sensitivity varies by subtype
Brighton criteria for GBS diagnosis	Class IIa, Level C	Brighton Collaboration, Vaccine 2011
IgA level before IVIG	Class I, Level C	Standard safety measure
LP with albuminocytologic dissociation	Class I, Level B	Classic diagnostic finding; may be normal in first week

APPENDIX: HUGHES GBS DISABILITY SCALE

Grade	Description
0	Healthy
1	Minor symptoms or signs, able to run
2	Able to walk ≥10m without assistance but unable to run
3	Able to walk ≥10m with assistance (walker, cane, person)
4	Chairbound or bedbound
5	Requiring assisted ventilation
6	Dead

APPENDIX: BRIGHTON CRITERIA (DIAGNOSTIC CERTAINTY)

Level	Requirements
Level 1 (Highest)	Bilateral flaccid weakness + decreased/absent reflexes + electrophysiology consistent + CSF protein elevated with WBC <50 + no alternative diagnosis
Level 2	Bilateral flaccid weakness + decreased/absent reflexes + CSF or electrophysiology consistent + no alternative diagnosis
Level 3	Bilateral flaccid weakness + decreased/absent reflexes + no alternative diagnosis

APPENDIX: IVIG INFUSION PROTOCOL (TYPICAL)

Step	Rate
Initial 30 min	0.5 mL/kg/h
If tolerated, increase q30min	1.0 → 2.0 → 3.0 → 4.0 mL/kg/h
Maximum rate	4.0-8.0 mL/kg/h (product-specific)
Pre-medication	Acetaminophen 650 mg + diphenhydramine 25-50 mg PO 30 min before; hydration 500 mL NS

APPENDIX: 20/30/40 INTUBATION RULE

Parameter	Threshold for Intubation
FVC	<20 mL/kg
NIF (MIP)	Weaker than -30 cmH2O
FVC decline	>30% from baseline
Additional clinical signs	Inability to count to 20 on single breath, paradoxical breathing, use of accessory muscles, tachypnea >30, weak cough