Transcript Size: 4 MB - neurological complications neuraxial blockade

Neurological complications of
centrineuraxial blockade
Dr. S. Parthasarathy
MD, DA, DNB, Dip Diab.MD ,DCA, Dip
software based statistics,
PhD (physiology)
History
• neurologic complication England on October 13, 1947.
• two healthy men -,meniscectomy , hydrocele.
• Both men developed permanent spastic paralysis after
administration of intrathecal anesthesia.(hyperbaric dibucaine
• Phenol – sterilize ampoules – crack in ampoules – danger
• Sir Robert Macintosh supported this theory and testified
before the court to this effect.
History – contd.
• Recent scholarship has demonstrated that phenol
was unlikely the more likely suspect was the acidic
solution used to clean the sterilizer.
• First patient – more severe ,,, second patient less
severe
• Finally, pathologic findings support the conclusion
that an acidic solution was introduced into the
subarachnoid space
Incidence
• 4 /10,000
• 0.04 %
• Permanent damage is extremely rare
Causes
• Cord Trauma
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Needle trauma
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Local Anaesthetic
toxicity
• Cord Ischemia
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Anterior Spinal Artery
Syndrome
• ICAT
• Cord compression
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Hematoma
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Needle trauma
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Tumor
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Vascular anomaly
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Bleeding disorder
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Abscess (infection)
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Exogenous infection
via a needle
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Hematogenous
Pre-existing neurological diseases
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Multiple Sclerosis
Spinal Stenosis
Gullian – Barre Syndrome
Diabetic Neuropathy
Demyelination
Direct needle Trauma
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The spinal cord has no sensory receptors
sensory inputs from the meninges -inconsistent.
Sites
Spinal cord,
Nerve roots
Nerves
Risks
• Direct needle or catheter trauma to the spinal
cord may be associated with
• inaccurate determination of vertebral levels,
anatomical variation in the terminal portion of
the conus medullaris,
• incompletely fused ligamentum flavum
• Paresthesia- needle or catheter or injection !!no
• Post op paresthesia !!
We may not know what happens
inside
• A traumatic needle induced lesion at the conus level
can cause a severe disturbance of the intramedullary
circulation that could lead to the formation of a rod
shaped cavity in the central region of the conus
• Dangerous deficits !!
Prevention
Local Anaesthetic Toxicity:
• prolonged exposure, high dose and
concentrations at the spinal roots
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Risk factors
Infusions
Already mechanically damaged ,
Adrenaline
Cauda equina ( susceptible )
Transient Neurologic Symptoms
• Schneider et al in 1993,
• appear within a few hours of spinal anaesthetic until
approximately 24 hours after a full recovery from an
uneventful spinal anaesthetic.
• L5 – S1 dermatomal pain
• The L5-S1 dermatome is most often involved and this is
because the L5-S1 spinal roots lie in the most dorsal portion
of the spinal canal,,,, fifth day normal
• No deficit , -- MRI normal
• 5 % hyperbaric lignocaine
• Seven times more common than other local
anaesthetics
• Isobaric also reported
Cauda Equina Syndrome
• varying degree of saddle anaesthesia, sphincter dysfunction
resulting in bladder and bowel problems and sometimes
paraplegia.
• Hyperbaric lignocaine 5 %, High doses , repeat
• micro catheters ,- poor mixing – more local
• In vitro evidence suggests that local anaesthetics produce
excitotoxic damage by depolarising neurons and increasing
intracellular calcium. Local anaesthetics can cause neuronal
injury by damaging neuronal plasma membrane
Wake up !!
Spinal Epidural Hematoma
• The calculated incidence of neurologic dysfunction
resulting from hemorrhagic complications associated
with epidural anaesthesia is less than 1 in 150,000
and less than 1 in 220,000 with spinal anaesthesia.
• Anticoagulants, difficult spinal, liver , renal diseases
, old age and spinal abnormalities
Spinal Epidural Hematoma
• Bleeding and hematoma occurs not only due to injury
to the epidural veins but can occur spontaneously
• Unprotected valveless epidural veins – increased intra
abdominal pressures
• The location is usually at the level at which the spinal
anaesthetic was given,
• may extend over a few vertebral body levels.
• Spontaneous hematoma is most often located in the
thoracic and cervico -thoracic region
Hematoma
• The patient usually presents with a severe, localised
constant back pain with or without a radicular
component that may mimic disc herniation.
• Associated symptoms may include weakness,numbness,
and urinary or fecal incontinence.
• Signs of spinal cord and nerve root dysfunction appear
rapidly and may progress to paraparesis or paraplegia
Hematoma
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Spinal block wears off
Return of weakness
24 – 48 hours – sometimes a week
MRI spine – hematoma, also vascular
anomalies
• 0 – 6 hours – hyperacute stage
• 7 -72 hours acute stage
• Early surgical decompression – ideal
Infectious complications
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epidural, spinal or subdural abscess;
paravertebral, paraspinous or psoas abscess;
meningitis;
encephalitis;
osteomyelitis
discitis.
Infection
• fever,
• backache, headache,
• erythema and tenderness at the insertion site.
• Additional -stiff neck, photophobia, radiating pain, loss of
motor function and confusion may indicate further
development of infectious complication.
• either manifest within few hours or weeks
• Periodic evaluation is essential for early identification of
infectious complications.
Infection !!
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Routine blood evaluation
CSF
Catheter tip culture
Immunocompromised !!
Appropriate antibiotics
Antisepsis
Drainage
Physician consult
Post. Inf. Cerebellar and vertebral
Posterior - 2
Anterior - 1
Anterior Spinal artery Syndrome
Posterior
Anterior
End
arteries
Adamkiewicz
Adamkiewicz
• typically arises from a left posterior intercostal
artery, which branches from the aorta, and
supplies the lower two thirds of the spinal
cord via the anterior spinal artery.
• Not complications of neuraxial blockade
• Surgical aneurysm repair
• Bronchial artery embolization
Anterior Spinal artery Syndrome
• Systemic hypotension ,Adrenaline
• Atherosclerosis , Old age
• Aortic or spinal cord procedure
• Adamkiewicz is not present or abnormal
• sudden onset of flaccid paralysis of lower extremities, after
recovery from the effect of spinal anaesthetic.
• Classically proprioception and sensation is spared or
preserved relative to the motor loss
What is what ??
Arachnoiditis and spinal drug administration
• arachnoiditis results from spinal administration
of approved spinal drugs. – unlikely
• Wrong drugs – yes
• Occult bleeds, injuries can increase the chances
• Arachnoiditis
• extensive sclerosis of arachnoid membranes with
constriction of the vascular supply to the neural
tissue
• Cauda Equina Syndrome.
• The symptoms of arachnoiditis include constant
burning pain in low back and legs, urinary
frequency or incontinence, muscle spasm in the
back and legs and variable sensory loss or motor
dysfunction.
Limit , diagnose and treat
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Injury –
Disease and anticoagulation
Tumors
Drug and dosage and infusions
MRI – if urgent CT
Compressing – do surgical intervention ,
antibiotics
Spinal anaesthesia in patients with
preexisting neurological disease.
• Although the use of spinal anaesthesia in patients with
preexisting neuropathies is controversial, the reported
incidence of neurological injury in these subgroup of
patients is very low.
• Is there an increase in damage if nerves are already
damaged ?
• Risk benefit ratio ??
'‘Double Crush” phenomenon
• patients with preexisting neurological compromise
may be more susceptible to injury at another
site,when exposed to secondary insult
• Secondary insult means – toxic, ischemic , traumatic
etc..
• However spinal anaesthesia may be advantageous in
patients
with
degenerative
diseases
such
as
Parkinson's Disease, Alzheimer's Disease and in
Amyotrophic Lateral Sclerosis.
• In patients with chronic spinal cord injury spinal
anaesthesia may be a valuable tool to prevent
autonomic hyperreflexia.
• In demyelinating diseases ,
Spinal
Gullian – Barre Syndrome,
worsening neurologic symptoms, prolonged duration of
action of local anaesthetics, triggering of underlying
disease and cardiac arrest after low subarachnoid block
have been reported in the literature
Spinal stenosis
• Spinal stenosis is a risk factor for postoperative cauda
equina syndrome and paraperesis even after
uneventful spinal anaesthetic.
• But reports of uneventful spinal after laminectomy
reported
• Imaging !!
Diabetic neuropathy
• Already nerve damage – more prone
• Ischemia – more drug for the nerves
• Chances !!
• Human data lacking
Overall
• Risk benefit ratio
• less potent local anesthetic, minimizing local
anesthetic dose, volume, and/or
concentration, and avoiding or using a lower
concentration of vasoconstrictive additive
Summary
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History
Incidence
Causes
Needle trauma
TNS, cauda equina , spinal artery
Pre existing diseases
Thank you all