Please enable JavaScript.
Coggle requires JavaScript to display documents.
Neurological impairment in ICU (Differential diagnoses (Critical illness…
Neurological impairment in ICU
Clinical examination
Normal higher functions and cranial nerves favour a critical illness neuromyopathy (CINM)
Symmetrical features on peripheral neuro exam also favours CINM
Critical illness myopathy often affects the diaphragm
Tendon reflexes are absent or profoundly decreased in neuropathies and decreased in myopathies. They should be normal in a deconditioned or residual sedation scenario.
Plantars are unhelpful as they are equivocal
Lack of focal neurology or relative sparing of distal motor power (watershed infarction) tends to exclude central causes
Investigations
Check biochem and ABGs (U+E, LFT, PO4, Ca, Mg, pH, PaC02), FBE and inflamm markers, vit D and Gent level
Review cultures and sensitivities and Abx used to determine the possibility of ongoing or resistant infection
CK (elevated in myopathies) timing of test to be considered - best done in first 7 days
Nerve conduction studies and EMG studies help support diagnosis of neuropathy and myopathy (vs severe deconditioning or central causes)
CSF analysis (GBS), may be required
Muscle biopsy may be required
MRI if central cause suspected or NCS and EMG dont support CINM
Differential diagnoses
Critical illness myopathy / acute quadriplegic myopathy (high dose steroids, NMB use, B agonists)
Critical illness polyneuropathy/myopathy (SIRS, sepsis MODS)
Residual sedation and other drug influences (renal/liver impairment, aminoglycoside on NMJ)
Electrolyte abnormality (PO4, Ca2+, K+)
Deconditioning with weakness exacerbated by subclinical sepsis
Underlying polyneuropathy/myopathy exacerbated by critical illness (ETOH, B12 deficiency, paraneoplastic, diabetes)
GBS
Rhabdomyelosis should be considered in renal failure
Acute myelitis or watershed infarction (acute upper motor neurone lesions may not yet have developed hypertonia and hyper-reflexia)
Autoimmune neuropathy or myopathy (rare)