Peripheral neuropathies

Question 0

Patient is admitted to ICU with SBO and shock, intubated and the works. Critically ill, has had IV ABs, steroids, IVF. Failed wean at 7 days.

What are the broad differentials and any useful tests now?

Answer 0

Critical care myopathy - elevated cK, predominantly prox flaccid limb weakness.

Corticosteroid myopathy - normal cK, prox weakness, preserved reflexes, EMG = normal or mildly myopathic

Guillain-Barre - normal cK, otherwise can be same as critical care myopathy.

Question 1

Treatment for AIDP?

Answer 1

Plasma exchange: Earlier improvement in muscle strength, reduced need for mechanical ventilation, and better recovery (reduced disability).

IVIG (3 or 6 days, depending on severity) is non-inferior to plasma exchange.

Corticosteroids have no role - no benefit and may even worsen.

Supportive care:

• Monitoring for respiratory muscle failure (FVC best: <20 mL/kg = indication for ETT) and manage respiratory failure.
• Watch for and manage dysautonomia. Monitor: BP, fluid status, and cardiac rhythm, bowel and bladder care.
• VTE prophylaxis.
• Pain control (neuropathic pain common).
• Rehabilitation.

Question 2

Poor prognostic factors in AIDP?

Answer 2

Factors associated with a poor prognosis for recovery from GBS include:
● Older age
● Rapid onset (less than seven days) prior to presentation
● Severe muscle weakness on admission
● Need for ventilatory support
● An average distal motor response amplitude reduction to <20 percent of normal
● Preceding diarrheal illness