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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 • Needle trauma • Local Anaesthetic toxicity • Cord Ischemia • Anterior Spinal Artery Syndrome • ICAT • Cord compression • Hematoma • Needle trauma • Tumor • Vascular anomaly • Bleeding disorder • Abscess (infection) • Exogenous infection via a needle • Hematogenous Pre-existing neurological diseases • • • • • Multiple Sclerosis Spinal Stenosis Gullian – Barre Syndrome Diabetic Neuropathy Demyelination Direct needle Trauma • • • • • • 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 • • • • • 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 • • • • 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 • • • • • • 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 !! • • • • • • • • 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 • • • • • • 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 • • • • • • History Incidence Causes Needle trauma TNS, cauda equina , spinal artery Pre existing diseases Thank you all