Neuromuscular Disorders in ICU Flashcards
What are the categories of neuromuscular disorders?
- Spinal level
- Neuromuscular junction
- Non-specific muscle contraction
- Peripheral neuropathy
What are examples of diseases that stem from the spinal anterior horn cells?
- Motor neurone disease
- Poliomyelitis
What is motor neurone disease (MND)?
- Group of diseases affecting motor neurons in brain & spinal cord
- Rapidly progressive, fatal, no cure
- Unknown cause
- Life expectancy approx 2-5 years from diagnosis
What are examples of neuromuscular junction pathologies?
- Myasthenia gravis
- Botulism (rare, related to bacteria)
What is myasthenia gravis?
- Chronic, autoimmune muscular disease
- Varying differences in muscle weakness
- Normal life expectancy
What is ICU acquired weakness?
- Muscle contraction pathology
- Critical illness is only cause of weakness
- Can be critical illness myopathy (CIM) or critical illness polyneuropathy (CIP)
What are the risk factors for ICUAW?
- Prolonged MV
- Severe systemic inflammation
- Corticosteroids & NM blocking agents
- Poor glycaemic control
- Immobility
What is a common peripheral nerve conduction disease?
Guillain Barre syndrome
What is Guillain Barre syndrome (GBS)?
- Demyelinating peripheral neuropathy
- Most common form of neuromuscular paralysis in developed countries
- Umbrella term for heterogenous group of immunologically mediated disorders of peripheral nerve function
What is the pathophysiology of GBS?
- Infiltration of mono-nuclear cells of endoneurium
- Inflammation along length of nerve
- Focused at nerve roots, spinal nerves & plexuses
- Macrophages actively strip myelin from Schwann cells & axons
What are some of the variations of GBS?
- 45% include cranial nerves
- 1/3 of cases require MV
- Sensory loss (vibration, proprioception, pain or hyperaesthesia)
- Autonomic dysfunction
What are some of the types of autonomic dysfunction that may occur in GBS?
- Orthostatic hypotension
- Hypotension
- Hypertension
- Bradycardia
- Ventricular tachyarrhythmias
- Paralytic ileus
- Urinary retention
- Abnormal sweating
- Bladder dysfunction & constipation are common
What are the required signs/symptoms for GBS diagnosis?
- Progressive weakness in both arms & legs (begins in lower extremities & ascends)
- Areflexia (loss of reflexes)
- Ataxia (loss of bodily movements)
- Minimal muscle atrophy
- May have problems with respiration, talking, swelling, bladder & bowel dysfunction
What are the risk factors for GBS?
- Possibly autoimmune
- Association with immunisations
- Frequently preceded by mild respiratory or intestinal infection
What are the supportive signs/symptoms for GBS diagnosis?
- Progression of symptoms over days to 4 weeks
- Symmetry of symptoms
- Mild sensory symptoms/signs
- Cranial nerve involvement
- Recovery beginning after 2-4 weeks
- Autonomic dysfunction
- No fever at onset
- High concentration of protein in CSF
- Electrodiagnostic features
