4Autonomic Hyperreflexia Recently, I was assigned the anesthetic care of a patient with a SPI and Hx of AH. 6 yrs ago he initiated anti-HTNs therapy, had a subsequent bout of orthostatic hypotn, and suffered a fall a flight of stairs; transecting his spinal C5-C7. AH has anesthetic implications that warrant review for even the most experienced of anesthesia providers since it is a potentially life threatening hypertensive complication that occurs in greater that 85% of pt with SPI above T6.
5AH Case Presentation63 y/o M, scheduled for a sigmoid colectomy w/ colostomy.NKABMI 29.3 / 98 KgTobacco: 20 pk/yr (quit 2007)
6AH Case Presentation Active Problems Quadriplegia—C5-C7 transectionX6 yrsChronic painOxycodone 5 mg 1-2 tabs q 4 hrsVenlafaxine 75 mg dailyMild RAD—Duoneb prn (rare use)HTN resolved after smoking cessation & accident
7AH Case Presentation Medical History AH during previous anestheticHTN-resolvedPertinent Surgical and anesthesia hx when arrives.
9AH Case Presentation Airway/ROS Auscultation:RRRCTAAirwayROM: (-)Dentition: (-)Neck: (-)T→D: (-)ULBT: grade IMouth: > 3 cmMP: 2Anatomy palp: easyThe preop eval showed sensory loss below T4 & motor loss below C7. No CV or pulm complications. Anemia. BLE contractures. Straight cath. Anesthesia hx of AH.
10AH Case Presentation Spinal & Induction L3-L4 (+CSF)Midazolam 1 mg IVBupi 12 mg + Epi wash500 mL LR co-loadInductionLidocaine 60 mgFentanyl 100 mcgPropofol 120 mgRocuronium 50 mgStandard monitoring was applied. SAB was placed at the L3-L4 interspace in the L lateral decub position w/ slight reverse Trendelenburg. Sensory was maintained at T4 (nipple line). VSS throughout, slight drop in bp and hr
11AH Case Presentation: Maintenance, Emergence, & Postop Sevoflurane 1-1.5%BIS 40-50Fentanyl prnNipride gtt (readily available)VSS throughout case. No incidence of AH. [Add additional information once arrives.]
12AH Case Presentation: Maintenance, Emergence, & Postop VSS throughout case. No incidence of AH
13Autonomic Hyperreflexia/Dysreflexia Episodic & potentially life-threatening HTN that develops in pts w/ spinal cord lesion at or above T6.Occurs > 85%Caused by noxious, visceral, or nociceptive stimuli below spinal lesionSBP ↑ > mmHgSBP increase of greater than is considered a dysreflexic episode.I have read case studies and other literature that reported AH below T6 to as low as t10 journals
14VA & Spinal Cord Injury (SCI) 250,000 Americans w/ serious SCI42,000 SCI Veterans/heroes26,000 (2008)13,000 specialty care (2008)VA is on of 20 professional organizations in the Consortium for Spinal Cord Medicine—develops guidelines to improve care in all americansVA provides coordinated lifelong care for veterans of all ages: emergency care, medical and surgical surgical stabilization, surgical care, and specialty sustaining care.
15AH Pathophysiology Review Stimulus below transection.Activation of preganglionic sympathetic nervesVasoconstrictionHTNStimulation of carotid sinus = bradycardiaReflexive cutaneous vasodilationStimulus > afferent transmission of impulses to spinal cord proper/parenchyma > impulses increase SNS activity over the splanchnic outflow tract > normal outflow modulation of inhibitory impulses does not occur > vasoconstriction below spinal cord transection > systemic hypertension and stimulation of the carotid sinus > reflex bradycardia > HTN & bradycardia are the hallmarks of AH > also a reflexive cutaneous vasodilation above lesion
16AH Clinical Presentation Awake:C/o HA, blurred vision, nasal stuffinessAnesthetized:Hallmarks: HTN & BradycardiaPiloerection & flushing (above)Untreated:Loss of consciousnessSeizuresCardiac dysrhythmiasCerebral, retinal, or subarachnoid hemorrhage↑ afterload → LV failure & pulm edemaUntreated, precipitate to cerebral, retinal, subarchnoid hemorrhageLoss of consciousness, szs & cardiac dysrhythmias
17Autonomic Hyperreflexia Recently, I was assigned the anesthetic care of a patient with a SPI and Hx of AH. 6 yrs ago he initiated anti-HTNs therapy, had a subsequent bout of orthostatic hypotn, and suffered a fall a flight of stairs; transecting his spinal C7. AH has anesthetic implications that warrant review for even the most experienced of anesthesia providers since it is a potentially life threatening hypertensive complication that occurs in greater that 85% of pt with SPI above T6.
18AH Anesthetic Implications Pre-op HEENT—↓ ROM & mouthing openingCV—↓ BP, orthostatic hypoTNPulm—↓ lung volumes, cough reflex, atelectasisGI—atonicity, full stomach?Renal—UTI, chronic FCCNS—bowel & bladder dysfunction, chronic & central painLow resting BP d/t diminution of SNS activity below lesionNifedipine is the most commonly used primary agent for management of AHAttention to CV, pulm function, volume status & airway
19AH Anesthetic Implications Treatment Nifedipine or prazosin prophylaxisSTOP the stimulus (if possible)Neuraxial block & GASAB > EA &/or GA > N2O + opioidVasodilatorsSNP, NicardipineBB for tachyarrhythmiasNOTE: centrally acting hypotensive agents are not effective (clonidine)Direct vasodilators (SNP), ganglionic blockers (trimethaphan), alpha antagonists (phentolamine).Intrasphincteric anal block for anorectal proceduresEA for laboring women
20AH Anesthetic Implications Clinical Pearls NDNMB prnSCh & profound hyperK+Common triggers:Irritation of urinary bladder, colon, & laborWaning of anesthesia (post-op)Literature is lacking for definitive treatmentLow BP d/t diminution of SNS activity below lesionNifedipine is the most commonly used primary agent for management of AH
21ReferencesFleisher LA, Roizen MF. Essence of Anesthesia Practice. 3rd ed. Philadelphia/Elsevier. 2011; 10.Hines RL, Marshall KE eds. Stoelting’s Anesthesia and Co-Existing Disease. 5th ed. Philadelphia: Churchill Livingstone/Elsevier; 2008.Lagarto, F., Pina, P.. Autonomic Dysreflexia - a clinical case: 4AP Eur J Anaesthesiol. 2012;29:75. Cited in: Your Full Text at Accessed April 02, 2013.Groothuis, Jan, Rongen, Gerard, Deinum, Jaap, et al. Sympathetic Nonadrenergic Transmission Contributes to Autonomic Dysreflexia in Spinal Cord-Injured Individuals. Hypertension. 2010;55(3): doi: /HYPERTENSIONAHAStevens, Robert, Bhardwaj, Anish, Kirsch, Jeffrey, Mirski, Marek. Critical Care and Perioperative Management in Traumatic Spinal Cord Injury. J Neurosurg Anesthesiol. 2003;15(3): Cited in: Your Full Text at Accessed April 02, 2013.
22ReferencesBROECKER, B., HRANOWSKY, N., HACKLER, R.. Low Spinal Anesthesia for the Prevention of Autonomic Dysreflexia in the Spinal Cord Injury Patient. Surv. anesthesiol ;24(3):184. Cited in: Your Full Text at Accessed April 02, 2013.Spinal Cord Injury Fact Sheet for Veterans: