Post spinal complications.ppt

spinal anesthesia complications

1. Post spinal anesthesia
complications

2. Outline
•Management of hypotension after spinal block
•Management of PDPH
•Management of shivering after spinal
•Management of high /complete spinal
•Management of nausea & vomiting after spinal

3. Post spinal Hypotension:
Hypotensionduringinductionofregionalanaesthesiain
obstetricpatientsisassociatedwithbothmaternalandfetal
morbidity.
Thesympathectomythatoccurswithneuraxialblockade
causeshypotensioninwomenwhoreceivespinalanaesthesia
forcaesareansection.
Spinalhypotensioncanoccurabruptlyandmayleadto
cardiovascularcollapse.Itcausesmaternalnauseaand
vomitingandfetalacidosis

4. HypotensioncausedbyareductioninSVRisnormally
compensatedbyanincreaseinCO.
UnderSAtheincreaseinvenouscapacitancedecreaseCO,
becauseofveno-dilatationinthelowerpartofthebody.
Thesituationisworsenedinpregnancybyaortocaval
compression.Thus,morethan25%,COusuallydecreases.
Thisisthecombinedeffectofreducedcardiacoutputand
decreasedSVRaccountsforhypotensionafterspinal
anaesthesia.

5. Theincidence=>80%;theseveritydependsontheheight
oftheblock,thepositionoftheparturient,andwhether
prophylacticmeasuresweretakentopreventthehypotension.
Measuresthatdecreasetheriskofhypotensiontovarying
degreesincludeIVfluids,preventionofaorto-caval
compression,andmonitoringofBPatfrequentintervalsafter
placementofregionalanesthetic.

6. General management
Large(16G)IVcannula(ensureadequateflow)priorto
neuraxialblockade
Establishbaselinebloodpressure
1minuteNIBPcyclingpostneuraxialblockade(untilbaby
delivered)
Applywedgeforleftlateraltilt,considerfullleftlateral/asking
surgeontolifttheuterusifrefractoryhypotension

7. Management con…
Maintain SPB above 100 mmHg or >80% of pre-regional
blood pressure.
Bradycardia (HR<60 should be treated with atropine, if
accompanied with hypotension.
Do not use ephedrine before the baby is born.
Monitor blood loss to ensure that absolute hypovolemia does
not contribute to hypotension
Do not treat hypovolemia (eg hemorrhage) with vasopressors

8. Intravenous administration:
Crystalloidpre-loadinghasbeenshowntobeclinically
ineffectiveatpreventinghypotension.
Rapidcrystalloidadministrationafterinductionofspinal
anaesthesia(coloading)providesbettermaternalblood
pressurecontrolthanpre-loading(Dyeretal.2004)
butshouldbecombinedwiththeuseofvasopressorsto
preventhypotension.

9. Crystalloid vs colloid
Arecentsystematicreviewfoundthatcrystalloidwas
inconsistentinpreventinghypotensionandthatcolloidwas
significantlybetter.
Dahlgrenetalstudiedcrystalloidcomparedwithcolloidfor
preloading.Hypotensionwassignificantlyreducedafterlarger
volumesofcolloid.

10. Inanotherstudyofpreloadingcomparingpentastarchwith
crystalloid,Frenchetaldemonstratedareductioninthe
incidenceofhypotensioninthecolloidgroup(12.5%versus
47.5%).
Incontrasttothesestudieswhichallfoundcolloidpreloadof
benefit,Karinenetalfailedtofindanyreductioninthe
incidenceofhypotensionwhencolloidwasused

11. •Severalrecentstudieshavecomparedprehydrationversus
cohydrationbothwithcrystalloidsandcolloidsandshownthat
haemodynamicchangesandvasopressorrequirementare
similar.
•Metaanalysis(eightstudies,518parturients),theyfoundthat
theincidenceofhypotensiontobesimilarforcohydrationto
thatofprehydration.

12. VASOPRESSORS
Ephedrinehasbeenthedrugofchoiceformorethan30yearsinthe
treatmentofmaternalhypotensioninobstetricspinalanesthesiawhen
conservativemeasuresfail.
Sympthomimeticwithmixedeffect.
Ephedrinehasaslowonsetofactionmakingitdifficultto
titrateanduseitwithanappropriatebolusdose.
Asprovedbyvariousstudies,asingleprophylacticdoseis
ineffectiveandtheeffectivenessdependsonvariabledosesand
therateofadministration

13. EphedrinedepressesfetalPHmorethanPhenylephrine
–NganKneeetaldemonstratedthatephedrinecrossesplacenta
morereadilythanphenylephrine.
Phenylephrineisashort-acting,potent,vasoconstrictor
thatcausesanincreaseinbothsystolicanddiastolicblood
pressure.
–Itcounteractsthevasodilatationduetoneuraxialanaesthesia
directly,restoringbaselinebloodpressure.
Traditionally,itwasusedasasecondlinevasoconstrictor
inobstetricsbecauseoftheconcernsthatitcaused
vasoconstrictionintheuteroplacentalcirculation.

14. Whencomparedtoephedrineithasbeenshowntobe:
-Easiertotitrate
-Fasteronset
-Moreeffectiveatincreasingsystemicvascularresistance
-Causeslessmaternaltachycardiaandhypertension
-AssociatedwithimprovedfetalpH(NganKeeetal.2003)

15. Phenylephrinecanbeadministeredbybolusorinfusion.
Aprophylacticbolushasbeenshowntobesuperiortoa
therapeuticboluswithregardstoincidenceofhypotension,
NV(DasNevesetal.2010).
Metaraminol:-amixedalphaandbetaagonistcanbeusedfor
spinalinducedhypotension.
–NganKeeandcolleaguesdemonstratedthatMetaraminolwassuperior
toephedrineatmaintainingbothmaternalbloodpressureandfetalpH
duringspinalanesthesiaforcaesareansection.

16. PDPH
•Post-partum headache is the complaint of headache and neck
or shoulder pain in the first 6 weeks after delivery.
•Up to 39% of parturients experience headache in the first
postpartum week.
•Not all postpartum headache is PDPH, and as anaesthetists are
asked to review patients often, it is important to be aware of
the differential diagnoses

17. PDPH
•Inparturients,thecollectiveriskofunintentionaldural
puncturewithanepiduralneedleis~1.5%,andofthese,
52.1%willexperiencePDPH.
•Afterspinalinjection,theincidenceofheadacherangesfrom
1.5to11.2%,dependingonthesizeandtypeofneedle.

18. PATHOGENESIS
CSFleakageintotheepiduralspaceviaatearinthedura.
CSFlossleadstoareductioninintracranialpressureand
downward tractiononpain-sensitiveintracranial
structures(veins,meningesandcranialnerves)resultingina
headachethatisclassicallyworseintheuprightposition.
Thefallinintracranialpressuremayalsocause
compensatorycerebro-vascularvenodilationandthismay
contributetothedevelopmentoftheheadache.

19. DIAGNOSIS AND DIFFERENTIAL
DIAGNOSIS
Thefundamentalprincipleintheassessmentofanyparturientwitha
post-partumheadacheistocarefullyconsiderthedifferential
diagnosis.
Infective:Meningitis,Encephalitis
Pharmacological/Metabolic:
DehydrationandCaffeinewithdrawal
Vascular:Migraine,Cerebralveinthrombosis,Cerebral
infarction,Subduralhaematoma&Subarachnoidhaematoma

20. Ahistoryandexaminationshouldbeperformedtakingaccount
ofthetimingoftheheadacheinrelationtotheneuraxial
procedure,thenatureoftheheadacheaswellasother
symptomsandsigns.
Inthecaseofaheadachefollowingaspinalprocedure,PDPH
ismorelikelyfollowingduralpuncturewithalargergauge
‘cutting’tippedneedleoraftermultipleattempts,
increasingthechanceofaCSFleak.

21. Classicfeaturesoftheheadachecausedbyduralpuncture:
Headacheisoftenfrontal-occipital.
Mostheadachesdonotdevelopimmediatelyafterdural
puncturebut24-48hoursaftertheprocedurewith90%of
headachespresentingwithin3days.
Theheadacheisworseintheuprightpositionandeaseswhen
supine.
Pressureovertheabdomenwiththewomanintheupright
positionmaygivetransientrelieftotheheadachebyraising
intracranialpressuresecondarytoariseinintra-abdominal
pressure(Gutsche’stest).

22. Associatedsymptoms:neckstiffness,photophobia,tinnitus,
visualdisturbanceandcranialnervepalsies.
MRImaydemonstratediffuseduralenhancementandbrain
descent.

23. MANAGEMENT
ConservativeManagement:Mostpost-duralpuncture
headachewillresolvespontaneously.
Conservativemanagementhastraditionallyinvolvedbedrest
andfluidsthoughthereislittleevidencetosupporteitherof
thesemeasures.
ArecentCochranereviewconcludedthatroutinebedrestafter
duralpunctureisnotbeneficialandshouldbeabandoned.
Whileroutineadministrationofadditionalfluidsmaybe
unnecessary,avoidanceofdehydrationisadvisabletohelp
limitheadacheseverity.=>traditional,lackevidence

24. Pharmacological
ManydrugshavebeenrecommendedtotreatPDPH,however
inthevastmajorityofcases,evidenceofeffectivenessis
limited.
Simpleanalgesiashouldbeinstitutedinallpatientswith
PDPH;regularparacetamolandnon-steroidalanti-
inflammatorymedicationsmaycontrolsymptomsadequately.

25. Caffeine:
CaffeinewasfirstreportedasatreatmentforPDPHin1949.
Caffeineisacentralnervoussystemstimulantandisthought
toinfluencePDPHbyinducingcerebralvasoconstriction.
Dosesfrom75–500mghavebeeninvestigatedandcaffeine
hasbeenadministeredorally,intramuscularlyand
intravenously.
Caffeineisassociatedwithadverseeventsincludingcardiac
arrhythmiasandmaternalseizures.Inhighdoses(probably
>300mg)caffeinemayenterbreastmilkandpotentiallyleadto
neonatalirritability.

26. Manyrandomizedtrialsfailedtoshowsuperiorityofcaffeine
overotherconservativemethodstotreatPDPH.
Morerecently,arandomized,double-blinded,placebo
controlledtrialbyRagabandFacharztin2014comparing
intravenouscaffeinewithplaceboshowsthatIVcaffeinecan
beeffectiveinreducingtherateandseverityofPDPH.
–Itmaybethatintravenouscaffeineiseffectivewhileoral
caffeineisnot.

27. Otherconservativetherapiesbeingstudiedthathave
alsoshowedpromisingresults.
Aprospective,randomized,double-blinded,placebo-
controlledtrialinwhichepiduralmorphinewas
administeredas2-3mgdose24hoursapartreduced
theincidenceofPDPHfrom48%to12%

28. Invasive Management
•Epiduralbloodpatch(EBP)afterobservationthatpatients
bloodspinaltapatlumbarpuncturewerelesslikelytodevelop
PDPH.
•thefirstepiduralbloodpatchwasperformedin1960bythe
Americansurgeon,DrJamesGormley.
•Just2mlofthepatient’sbloodwasinjectedduringthefirst
epiduralbloodpatchandtheheadachewasrelieved.

29. Epiduralbloodpatchinginvolvesinjectionofautologousblood
intotheepiduralspace.
ItremainsoneofthefewproventreatmentsofPDPHhowever
themechanismofactionremainsunclear.
Theresultingbloodclotmayhavea“patcheffect”onthedural
tearwhilethevolumeofbloodtransfusedintotheepidural
spaceraisesintracranialpressureandreducesongoingCSF
leak.

30. Effectiveness:
EarlystudiesoftheefficacyofEBP(upto90%)
Permanentcurebyasinglebloodpatchcanbeexpected
in50%ofpatients.
About40%ofpatientsrequireasecondbloodpatch
Despitethefallingsuccessrates,EBPremainsthemost
effectivetreatmentforPDPHandhasbeenshownina
randomizedcontrolledtrialtobemoreeffectivethan
conservativetreatmentintreatingestablishedPDPH.

31. Optimal Technique
EBPshouldbeperformedbytwopersonnel,onean
experiencedanaesthetist,theothercompetentintakinga
volumeofbloodfromthearm.Bothshouldemployfull
asepticprecautions.
ContraindicationstoEBPinclude:
-Sepsis,
-Coagulopathyand
-Patientrefusal.

32. EBPislikelytobemosteffectiveifperformedatleast24
hoursaftertheonsetofPDPH.
Volumesofbetween20-60mlsofbloodhavebeenused.
Optimalvolumeisunknownbutcurrentrecommendations
suggest10to20mlshouldbeinjected

33. Ifthepatientreportsdiscomfortinthebackduringthe
proceduretheinjectionshouldbestopped.
Thepatientshouldlieflatfor1-2hoursaftertheprocedure.
Thereisnoevidencethatbedrestforlongerthanthistimeis
beneficial.
Oncedischargedfromhospital,followupbytelephoneover
thefirstfewdaysafterEBPandreviewat6weeksis
recommended

34. Shivering:
Post-anestheticshiveringisspontaneous,involuntary,
rhythmic,oscillating,tremor-likemusclehyperactivitythat
increasesmetabolicheatproductionaftergeneralorregional
anesthesia.
Theprobablemechanismscouldbedecreaseincorebody
temperaturesecondaryto:
–sympatheticblock;
–peripheralvasodilatation;
–Increasedcutaneousbloodflow,whichleadstoincreasedheatloss
throughskin;
–coldtemperatureofoperationtheatre;rapidinfusionofcoldIVfluids;
andeffectofcoldanaestheticdrugsuponthethermosensitivereceptors
inthespinalcord

35. Management:
Two approaches in the management of PAS:
1)Non-pharmacological methods and
2)Pharmacological methods

36. Non-pharmacological methods:
A number of physico-chemical methods helpful to prevent
PAS
There are three basic strategies for the prevention and
treatment of hypothermia and shivering:
(i) minimising redistribution of heat;
(ii) cutaneous warming during anaesthesia: Passive insulation/Active
warming
(iii) internal warming.
Minimising redistribution of heat
This can be achieved by preoperative warming of peripheral tissues
It minimise phase I hypothermia
this would require subjecting patients to over 1 h of exposure to a
source of radiated heat pre-operatively

37. Cutaneous warming during anaesthesia
1.Passive insulation
2.Active warming
Internal warming

38. Review of literatures
9 RCTs for pethedine
4 RCT for tramadol, doxapram, and clonidine;
2 RCTs for nalbuphin
Evidence for these 5 drugs was found to be sufficient and
statistically significant.

39. Pethidine for treatment of PAS
Researchhasprovidedabundantdocumentationregarding
pethidine’spotentanti-shiveringeffects
However,themechanismfortheseeffectsispoorlyunderstood
Thisdrugexertsitsactiononĸ-opioidreceptors(KOR)andμ-
opioidreceptors(MOR),
–Researchersdevelopedthetheorythatmeperidine’sactiononKOR
mediatesitseffectonPAS.

40. Tramadol
Asyntheticandcentrallyactingopioid
MOA:
•activatingMORsandblockingnorepinephrineand
serotoninreuptake
–5HTcausedshiveringandvasoconstriction
–Norepinephrineloweredthenormalresting
temperatureandattenuatedthe5HTinduced
hyperthermia.
–Thebalanceb/n5HT&norepinephrineinputsmay
beresponsibleforthermoregulatoryresponse.

41. Tramadol versus Pethidine
All studies, whether RCTs or systematic reviews, found
tramadol as effective as meperidine
However, researchers considered tramadol qualitatively
superior than pethidine due to:
•a faster onset
•Easily available
•no recurrence of shivering,
•shorter duration of recovery, and fewer adverse effects
•Three RCTs reported that tramadol 0.5 to 1 mg/kg was
effective

42. Clonidine
An alpha 2 adrenergic receptors agonist
It is effective at 0.15mg dose to treat PAS
MOA
The hypothalamus, where alpha 2 receptors are found, is
responsible for controlling body temperature.
thought to work on hypothalamic receptors to inhibit
vasoconstriction and shivering or
at other CNS levels by altering incoming thermal
information

43. Magnesium sulphate and ketamine
•competitive antagonist at NMDA-receptors and was found to
stop post-anaesthetic shivering

44. Management of accidental high spinal blockade
Completespinalblockiscausedbylocalanaesthetic
interferingwiththenormalneuronalfunctioninthecervical
spinalcordandbrainstem.
RISKFACTORS:
Drugfactors
–dose
-Baricity
-Priordrugadministration
Patientfactors–
-bodymorphology
-Anatomicalorpathologicalfactors

45. Technique factors
1.Higherlumbarinsertionmayincreasefinalblockheight
2.Positionatandfollowinginjection–sittingmayminimize
cephaladspread
3.Spinalneedle–finergaugeandcephaladdirectionofneedle
holemayincreaseriskofhigherblock

46. MANAGEMENT
Managementissupportiveanddependentondegree
andheightofblock.
Earlyrecognitionisvitalasblockprogressionmay
bemitigated(reversetrendelenberg/headraised)or
seriouscardio-respiratorycompromiseavoided.

47. Management:
FEATURE MANAGEMENT
Bradycardia Vagolyticseg. atropine
Hypotension Sympathomimeticseg.
ephedrine, adrenaline
Vasopressorseg. metaraminol,
phenylephrine Fluid boluses
Leg elevation
Respiratory dysfunction Oxygenation Intubation and
ventilation
Loss of consciousness Secure airway , supportive
measures

48. Nausea and vomiting

49. Mechanisms of Postoperative Nausea and Vomiting in
Regional Anesthesia
Severaldifferentmechanismsmayplayaroleincausing
PONVinpatientswhoreceiveregionalanesthesia.
Inaretrospectiveanalysis,CrockerandVandamfoundthat
hypotension(systolicbloodpressure<80mmHg),ablock
higherthanT5.

50. Management:
•Phenothiazines:
Promethazine,prochlorperazine,andchlorpromazineareall
phenothiazines,exerttheirantiemeticeffectsbydirectlyacting
onthecentraldopaminergicreceptorsofthechemoreceptor
triggerzone.
Theseagentsaremosteffectiveinthetreatmentofopioid
inducedPONV,buttheiruseastheprimarytreatmentfor
PONVislimitedbytheirtendencytocausesedation.

51. Butyrophenone
Droperidolistheonlybutyrophenonecurrentlyusedinthe
treatmentofPONV.
Likethephenothiazines,droperidolactscompetitivelyon
centraldopaminergicreceptorsandisassociatedwithsedation,
lethargy,agitationandextraphyramidaleffects,

52. Antihistamines
Diphenhydramine,hydroxyzine,Vistaril®,andcyclizine
areallantihistamineswhichworktopreventnauseaand
vomitingbyactingontheH1receptors.
Usingaspostoperativeagentsislimitedbytheexcessive
sedationassociatedwithadministration.

53. Anticholinergic
Scopolamineisananticholinergicagentthatactsonthe
muscarinicandhistaminicreceptorsofthevestibularapparatus
usedtoreducetheincidenceofPONV.
Veryeffectiveinpatientstreatedwithopioids,
Complications:useislimitedbyahighincidenceofsedation,
dry-mouth,dysphoria,confusion,disorientation,visual
disturbancesandhallucinations.

54. Benzamides
Metoclopramideandtrimethobenzamidearebenzamides
–actonbothcentraldopamineandserotoninreceptors,with
bothprokineticandantiemeticeffects.
Metoclopramideincreasesgastrointestinaltractmotility,
decreasinggastricemptyingtimeandgastricvolume,andis
usuallywelltoleratedinadultpatients.

55. Serotonin antagonists
Ondansetron,granisetron,dolasetron,tropisetronandother
serotoninantagonistshavebeenshowntoprovideeffective
treatmentandprophylaxisofPONVandareassociatedwitha
lowincidenceofmildsideeffects.
–Theyarenotdopamine,muscarinicorhistaminereceptorantagonists.
Others
Anxiolytics-Midazolam
Steroids=>Dexamethasone

56. THANK YOU!!!