Treatment of Acute and delayed complications of neuroaxial anesthesia
High Spinal Hypotension Seizures Neuropathy Also on we will discuss: PDPH Differential Diagnosis and Treatment
Hypotension
Hypotension after neuroaxial Underlying Pathophysiology for Hypotension - Sympathectomy resulting in decreased SVR, decreased venous return and decreased preload Fluid bolus is first line treatment to increase venous return and increase preload, utilizing Frank-Starling curve to increase contractility of heart The practice of pre-hydration with 500-1500 mL of crystalloid has shown to decrease hypotension in some studies and in other studies it has not
Hypotension after neuroaxial If hypotension does not resolve with fluid bolus, vasopressors are usually indicated to increase SVR For long time, Ephedrine was considered the vasopressors of choice because of its alpha and beta actions, it increases HR, CO, and SVR Phenylephrine is becoming the popular vasopressors in current literature because it has shown to cause less fetal acidosis when compared to Ephedrine
Bezold-Jarish Relfex Triad of: Bradycardia, Hypotension, & Cardiovascular collapse Caused by stretch receptors in the atrium sensing decreased preload causing slowing of the heart in order to increase preload
High Spinal The three most important factors in determining block height: Baricity of solution Position of patient Dose and Total volume of local anesthetic Speed, Height of patient, and other factors have not shown an association with blockade height
High or Total Spinal Fluids to combat decreased preload/venous return, need to maintain coronary and cerebral perfusion Respiratory support (100% Facemask vs Manual assist) Tracheal intubation if unconsciousness develops Atropine, in increments of 0.4 mg to treat bradycardia Ephedrine or Phenylephrine to treat low SVR and raise perfusion May need to consider intravenous infusion of vasopressors, like epi or norepinephrine until spinal wears off Maintain supportive measures until spinal wears off
CSF Lavage for High Spinal CSF Lavage is a recognized treatment option for high spinal anesthesia Usually done with an intrathecal epidural catheter, remove 10 mL of CSF and replace with preservative free sterile saline. No exact data exist on how many times to do this, but roughly 40-50 mL will replace entire CSF volume Significantly shortens duration of high spinal and may prevent progression to state of emergency
Seizures A seizure after neuroaxial anesthesia is most likely related to systemic toxicity from intravascular absorption Treat with supportive measures Consider Intra-lipid 1.5 ml/Kg bolus followed by infusion of 0.25 - 0.5 ml/kg over 30-60 minutes
Neuropathy after Neuroaxial First off must rule out epidrual hematoma or abcess. If patient has progressive sensory and motor weakness get MRI Consider Transient Neurological Symptoms (TNS) - associated with Lidocaine, micro puncture catheters, obesity and lithotomy position. Remember has no motor weakness Document any pre-existing neurological problems and post-operative changes
Neuropathy Cauda Equina Syndrome - associated with continuous intrathecal catheters and 5% lidocaine. Associated with sphincter dysfunction, sensory and motor deficits and paralysis Can lead to permanent dysfunction
Differential Diagnosis and Treatment Options PDPH Differential Diagnosis and Treatment Options
Risk Factors Young, skinny females Large needle Non-pencil point needles
Symptoms Headache, that is worse when sitting or standing, and improves when laying flat Often described as throbbing and constant, and associated with nausea/vomitting/photophobia Onset usually within 12-72 hours after puncture Usually resolves in a week untreated
Differential Diagnosis Meningitis - usually not positional and has fever Migraine Dehydration
Treatment 50% of patients who experience a "wet tap" will go on to develop PDPH. Prophylactic epidural blood patch within first 24 hours has a 71% failure rate compared to 4% failure rate after 24 hours - Be conservative
Conservative Measures Fluids and Hydration - trying to increase CSF production Encourage ambulation as tolerated, bed rest has not shown to help Caffeine - helps by causing cerebral vasoconstriction Analgesics Stool softners to prevent straining and valsalva
Epidural Blood Patch Resolve about 70-95% of PDPH after first try Second blood patch resolves about 70-95% of those patients that didn't respond to first Ideally want to to choose a level below original puncture site - blood travels up (opposite of what you would think) Usually inject 10-20 mL of patients own blood into epidural space or until patient feels intense pressure Works by coagulating and causing mass effect, thereby "closing" off the hole