1. The AutonomicThe Autonomic
Nervous System AndNervous System And
Its Implications InIts Implications In
AnaesthesiaAnaesthesia
Guided byGuided by ::
Dr. BakshiDr. Bakshi
MadamMadam
Presented by :Presented by :
Dr. Neha SoaresDr. Neha Soares
Dated : 26Dated : 26thth
July 2007July 2007
2. IntroductionIntroduction
AnatomyAnatomy
PhysiologyPhysiology
Drugs acting on ANSDrugs acting on ANS
Tests for autonomic integrityTests for autonomic integrity
Anaesthesia and ANSAnaesthesia and ANS a) Generala) General
b) Regionalb) Regional
Autonomic reflexes during anaesthesia andAutonomic reflexes during anaesthesia and
surgerysurgery
ANSANS dysfunctiondysfunction
Anaesthesia in patients with ANS dysfunctionAnaesthesia in patients with ANS dysfunction
ANS in intensive careANS in intensive care
ANS and chronic painANS and chronic pain
4. ANATOMYANATOMY
ComprisesComprises all afferent fibresall afferent fibres from the CNSfrom the CNS
except those supplying skeletal muscles.except those supplying skeletal muscles.
Includes :Includes :
1)1) sympatheticsympathetic nervous systemnervous system
2)2) parasympatheticparasympathetic nervous systemnervous system
3)3) entericenteric nervous systemnervous system
5.
6. Sympathetic Nervous SystemSympathetic Nervous System
Originates from theOriginates from the Thoraco-lumbarThoraco-lumbar spinalspinal
cord (T1 to L2/L3)cord (T1 to L2/L3)
Composed of 2 neurons:Composed of 2 neurons:
a)a) prepre-ganglionic-ganglionic
b)b) postpost-ganglionic-ganglionic
9. UnpairedUnpaired prevertebral ganglia in the abdomen andprevertebral ganglia in the abdomen and
pelvispelvis
CeliacCeliac
Superior mesentericSuperior mesenteric
Inferior mesentericInferior mesenteric
Aortico renalAortico renal
• terminal/collateral gangliaterminal/collateral ganglia
10. Terminal or collateral gangliaTerminal or collateral ganglia
Small and few in numberSmall and few in number
PresentPresent near targetnear target organorgan
Eg. Nerves supplying adrenal medullaEg. Nerves supplying adrenal medulla
and other chromaffin tissueand other chromaffin tissue
CompriseComprise preganglionicpreganglionic fibres itself thatfibres itself that
pass to target tissue without synapsingpass to target tissue without synapsing
11. PARASYMPATHETIC NERVOUSPARASYMPATHETIC NERVOUS
SYSTEMSYSTEM
75% from75% from vagusvagus
Arises fromArises from III, VII, IX, X cranialIII, VII, IX, X cranial nerves,nerves,
S2-3S2-3 and occasionally S1and4and occasionally S1and4
Occur proximal to or within the innervatedOccur proximal to or within the innervated
organorgan
Hence,Hence, pre-ganglionic fibres very longpre-ganglionic fibres very long
PNS more targetedPNS more targeted
14. ENTERIC NERVOUS SYSTEMENTERIC NERVOUS SYSTEM
FoundFound within the wallswithin the walls
of the GIT, pancreasof the GIT, pancreas
and gall-bladderand gall-bladder
High degree ofHigh degree of
autonomyautonomy
Peristalsis andPeristalsis and
digestion persists evendigestion persists even
if sphincter functionif sphincter function
impaired followingimpaired following
SAB/transections.SAB/transections.
Submucous(Submucous(Meissner’sMeissner’s
plexus)plexus)
Myenteric(Myenteric(Auerbach’sAuerbach’s
plexus)plexus)
15. PHYSIOLOGYPHYSIOLOGY
EitherEither sympathetic or parasympathetic systemsympathetic or parasympathetic system
dominatesdominates a particular organ function, hencea particular organ function, hence
providing the resting toneproviding the resting tone
Few organs have only sympathetic innervation –Few organs have only sympathetic innervation –
blood vessels, spleen, piloerector muscles,blood vessels, spleen, piloerector muscles,
adrenal medulla, uterusadrenal medulla, uterus
Some organs have only parasympatheticSome organs have only parasympathetic
innervation – stomach, pancreasinnervation – stomach, pancreas
Sympathetic deals with FIGHT OR FLIGHTSympathetic deals with FIGHT OR FLIGHT
Parasympathetic deals with discrete adjustmentsParasympathetic deals with discrete adjustments
in relaxed homeostasisin relaxed homeostasis
16.
17. Target organTarget organ SNSSNS ReceptorReceptor PNSPNS
1.1. Hair follicleHair follicle
smooth musclesmooth muscle
2.2. Iris –radial msIris –radial ms
3.3. Iris- circular msIris- circular ms
4.4. Ciliary msCiliary ms
5.5. Glands – nasalGlands – nasal
parotid,lacrimalparotid,lacrimal
submandibularsubmandibular
gastric,pancraeticgastric,pancraetic
ContractionContraction
PiloerectionPiloerection
MydriasisMydriasis
NoneNone
SlightSlight
MydriasisMydriasis
SlightSlight
increaseincrease
Alpha1Alpha1
Alpha 1Alpha 1
BetaBeta
Alpha 1Alpha 1
NoneNone
NoneNone
MiosisMiosis
Accomoda-Accomoda-
tiontion
CopiousCopious
IncreaseIncrease
Action of SNS and PNS on various organsAction of SNS and PNS on various organs
24. NeurotransmittersNeurotransmitters
AcetylcholineAcetylcholine – Secreted by– Secreted by
**all preganglionic fibresall preganglionic fibres
*Postganglionic parasympathetic*Postganglionic parasympathetic
fibrespostganglionic sympathetic fibresfibrespostganglionic sympathetic fibres
of sweat gland,piloerctor muscle andof sweat gland,piloerctor muscle and
blood vesselsblood vessels
NorepinephrineNorepinephrine – Secreted by all– Secreted by all
postganglionic sympatheticpostganglionic sympathetic fibresfibres
25. Acetylcholine receptors are of 2 types:Acetylcholine receptors are of 2 types:
-- MuscarinicMuscarinic: action similar to that: action similar to that
produced byproduced by parasympatheticparasympathetic systemsystem
-- NicotinicNicotinic: action on: action on skeletal andskeletal and
ganglionicganglionic synapses onlysynapses only
Adrenergic receptors are of 2 tyes:Adrenergic receptors are of 2 tyes:
-- AlphaAlpha: alpha1(smooth muscle: alpha1(smooth muscle
vasoconstriction)vasoconstriction)
alpha2 (presynapses)alpha2 (presynapses)
-- BetaBeta: beta1 (cardiac tissue): beta1 (cardiac tissue)
beta2 (smooth muscle relaxation inbeta2 (smooth muscle relaxation in
somesome organs)organs)
26. Action of Important Drugs on ANSAction of Important Drugs on ANS
Site of actionSite of action
1.Sympathetic1.Sympathetic
andand
parasympatheticparasympathetic
gangliaganglia
2.Endings of post2.Endings of post
ganglionic nonganglionic non
adrenergicadrenergic
NeuronsNeurons
AgonistAgonist
1.Stimulate post-1.Stimulate post-
ganglionganglion- nicotin- nicotin
2.2.InhibitACh’trsInhibitACh’trse-e-
PhysostigminePhysostigmine
NeostigmineNeostigmine
ParathionParathion
Release NARelease NA
-TyramineTyramine
-EphedrineEphedrine
-AmphetamineAmphetamine
AntagonistAntagonist
HexamethoniumHexamethonium
MecamylamineMecamylamine
TrimethaphanTrimethaphan
High conc.Ach,High conc.Ach,
AnticholinestrsesAnticholinestrses
CurareCurare
Block NA synthBlock NA synth
-metyrosine-metyrosine
Stop NA storageStop NA storage
-reserpine,guane-reserpine,guane
thidinethidine
27. Site of actionSite of action
3.Alpha receptors3.Alpha receptors
AgonistAgonist
Stimulate alpha1Stimulate alpha1
-methoxamine-methoxamine
-phenylephrine-phenylephrine
Stimulate alpha2Stimulate alpha2
-clonidine-clonidine
AntagonistAntagonist
Stop NAStop NA
breakdownbreakdown
-MA inhibitors-MA inhibitors
FalseFalse
transmitterstransmitters
-methydopa-methydopa
-phenoxybenza-phenoxybenza
minemine
-phentolamine-phentolamine
-prazocin-alpha1-prazocin-alpha1
-yohimbin-alpha2-yohimbin-alpha2
29. TESTS FOR AUTONOMICTESTS FOR AUTONOMIC
INTEGRITYINTEGRITY
Autonomic functions can be evaluated by:Autonomic functions can be evaluated by:
HistoryHistory
Non-invasive testsNon-invasive tests
Invasive testsInvasive tests
30. HistoryHistory
CVSCVS (postural/orthostatic hypotension)(postural/orthostatic hypotension)
Fainting episodesFainting episodes
DizzinessDizziness
HeadacheHeadache
Diminution of visionDiminution of vision
GenitourinaryGenitourinary
ImpotencyImpotency
Incontinence of urineIncontinence of urine
Retention of urineRetention of urine
Frequency in urinationFrequency in urination
GlandsGlands
Decreased salivation with difficulty in eatingDecreased salivation with difficulty in eating
Decreased lacrimation causing eye irritationDecreased lacrimation causing eye irritation
Impaired sweating causing temperature elevationImpaired sweating causing temperature elevation
31. CNSCNS (affection of fibres supplying iris)(affection of fibres supplying iris)
Night-blindnessNight-blindness
Chronic diseasesChronic diseases
Diabetes mellitusDiabetes mellitus
Chronic renal failureChronic renal failure
HypertensionHypertension
Family historyFamily history
Personal historyPersonal history
Chronic alcoholismChronic alcoholism
Drugs like Antihypertensive antidepressants,Drugs like Antihypertensive antidepressants,
tranquilizers , diureticstranquilizers , diuretics
32. Non – invasive testsNon – invasive tests
Tests for cardiac vagal functionTests for cardiac vagal function
Respiratory sinus arrhythmiaRespiratory sinus arrhythmia
Vasalva ratio(Phase IV/II)Vasalva ratio(Phase IV/II)
Bradycardia duringBradycardia during
phenylephrine challengephenylephrine challenge
Absence of tachycardia withAbsence of tachycardia with
atropineatropine
Tests for sympathetic functionTests for sympathetic function
I) CARDIACI) CARDIAC
Tachycardia during standing orTachycardia during standing or
head-up tilthead-up tilt
Tachycardia during vasalvaTachycardia during vasalva
strain(PhaseII)strain(PhaseII)
II) PERIPHERALII) PERIPHERAL
Blood pressure overshootBlood pressure overshoot
after vasalva releaseafter vasalva release
BP increase with coldBP increase with cold
pressure testpressure test
Diastolic BP rise withDiastolic BP rise with
isometric handgripisometric handgrip
Systolic and diastolic BPSystolic and diastolic BP
response to uprightresponse to upright
positionposition
33. Respiratory sinus arrhythmiaRespiratory sinus arrhythmia
TestsTests parasympatheticparasympathetic functionfunction
Determines the max. to min. heart rate variation inDetermines the max. to min. heart rate variation in
forceful breathingforceful breathing
Patient in sitting or lying down positionPatient in sitting or lying down position
6 breaths/min.(5secs inspiration,5secs expiration)6 breaths/min.(5secs inspiration,5secs expiration)
Record mx. and min. HR and RR intervalRecord mx. and min. HR and RR interval
Av. variation should be >10 beats/minAv. variation should be >10 beats/min
E : I ratio = longest RR interval in expiration/shortest RRE : I ratio = longest RR interval in expiration/shortest RR
interval in inspirationinterval in inspiration
In <40yrs age,In <40yrs age, E:I<1.2 is abnormalE:I<1.2 is abnormal
34. Postural stress: Supine to standingPostural stress: Supine to standing
Tests theTests the sympatheticsympathetic functionfunction
Commonly performed bed-side testCommonly performed bed-side test
Note HR and BP in supine position afterNote HR and BP in supine position after
10mins rest10mins rest
Note changes in HR and BP after assumingNote changes in HR and BP after assuming
standing posture unaided after 50 secsstanding posture unaided after 50 secs
Drop of systolic BP >20mm of Hg and/orDrop of systolic BP >20mm of Hg and/or
diastolic BP >10 mm of Hg is abnormaldiastolic BP >10 mm of Hg is abnormal
Absence of tachycardia when standing isAbsence of tachycardia when standing is
abnormal (Marrey’s Law of baro receptorabnormal (Marrey’s Law of baro receptor
stimulation)stimulation)
35.
36.
37. Cold Pressure testCold Pressure test
Tests theTests the peripheral sympatheticperipheral sympathetic
vasoconstrictorsvasoconstrictors
Record BP 1min after immersing hand inRecord BP 1min after immersing hand in
ice cold waterice cold water
Both systolic and diastolic BP shouldBoth systolic and diastolic BP should
increase by 10mm of Hgincrease by 10mm of Hg
38.
39. Isometric Hand grip ExerciseIsometric Hand grip Exercise
Tests theTests the efferent sympatheticefferent sympathetic functionfunction
Sustained isometric contraction at 30% ofSustained isometric contraction at 30% of
patients max. strength should increase BP bypatients max. strength should increase BP by
10-15mm of Hg10-15mm of Hg
40. Vasalva ManouverVasalva Manouver
Tests bothTests both sympathetic and parasympatheticsympathetic and parasympathetic functionfunction
Subject sits quietly or lies supine, blows into a mouth-Subject sits quietly or lies supine, blows into a mouth-
piece with an open glottis, holds airway pressure ofpiece with an open glottis, holds airway pressure of
40mm of Hg for 15secs(PhaseII40mm of Hg for 15secs(PhaseII) and then releases the) and then releases the
pressurepressure
41. HR increasesHR increases 10to15secs after initiating blowing(PhaseII) and10to15secs after initiating blowing(PhaseII) and
before release of pressurebefore release of pressure
This implies that theThis implies that the sympathetic response is intactsympathetic response is intact
On release of strain(PhaseIV), preload and cardiac outputOn release of strain(PhaseIV), preload and cardiac output
restored,restored, BP overshootBP overshoot….this implies that the peripheral….this implies that the peripheral
sympathetic vasoconstriction is intactsympathetic vasoconstriction is intact
Baroreceptors stimulated, reflexBaroreceptors stimulated, reflex bradycardiabradycardia…this implies that the…this implies that the
parasympathetic system is intactparasympathetic system is intact
42. To test cardiac vagal function a ratio has been devisedTo test cardiac vagal function a ratio has been devised
Vasalva ratio = longest RR interval[max HR] in Phase IV(x)/Vasalva ratio = longest RR interval[max HR] in Phase IV(x)/
shortest RR interval[min HR] in Phase II(y)shortest RR interval[min HR] in Phase II(y)
Vasalva ratio <1.2 is abnormalVasalva ratio <1.2 is abnormal
43. EPINEPHRINE TESTEPINEPHRINE TEST ––
3 drops in eye at I min. interval 3 times3 drops in eye at I min. interval 3 times
Check pupil sixe at 15, 30 and 45 minsCheck pupil sixe at 15, 30 and 45 mins
Normal pupil = no effectNormal pupil = no effect
Sympathetically denervated pupil = dilationSympathetically denervated pupil = dilation
COCAINE TESTCOCAINE TEST ––
Method same as aboveMethod same as above
Normal pupil = dilationNormal pupil = dilation
Sympathetic denervated pupil = no change in sizeSympathetic denervated pupil = no change in size
HISTAMINE TESTHISTAMINE TEST ––
0.05ml of 1:1000 histamine injected intracutaneously0.05ml of 1:1000 histamine injected intracutaneously
Normal response – triple response with 1cm whealNormal response – triple response with 1cm wheal
Familial dysautonomia and peripheral neuropathy –Familial dysautonomia and peripheral neuropathy –
absent whealabsent wheal
44. EPHEDRINE TESTEPHEDRINE TEST ––
Give 25mg imGive 25mg im
Normal subjects = HR increasesNormal subjects = HR increases
Sympathetic denervation = no change in HRSympathetic denervation = no change in HR
ATROPINE TESTATROPINE TEST ––
Give 0.8mg imGive 0.8mg im
Normal subjects = HR increases by 20Normal subjects = HR increases by 20
beats/minbeats/min
Sympathetic denervation = no changeSympathetic denervation = no change
NEOSTIGMINE TESTNEOSTIGMINE TEST ––
Give 1mg imGive 1mg im
Normal subjects = HR decreasesNormal subjects = HR decreases
Parasympathetically denervated = no changeParasympathetically denervated = no change
45. Power Spectral Analysis of HRPower Spectral Analysis of HR
variabilityvariability
Slower periodic oscillations in heart, can be decomposedSlower periodic oscillations in heart, can be decomposed
into a series of sine waves with diff. amplitudes andinto a series of sine waves with diff. amplitudes and
frequenciesfrequencies
46. This frequency domain reveals aThis frequency domain reveals a consistant peakconsistant peak/ power at the breathing/ power at the breathing
frequencyfrequency 0.2 to 0.3Hz0.2 to 0.3Hz… this implies… this implies intact parasympatheticintact parasympathetic innervaton ofinnervaton of
SA nodeSA node
There is another peak at low frequenciesThere is another peak at low frequencies 0.05 to 0.150.05 to 0.15 Hz…due to changingHz…due to changing
cardiaccardiac sympatheticsympathetic activityactivity
This low frequency component is augmented by increased sympatheticThis low frequency component is augmented by increased sympathetic
drive eg.head up tilt, mental arithmatics and is reduced in quadriplegics duedrive eg.head up tilt, mental arithmatics and is reduced in quadriplegics due
to interrupted sympathetic pathways.to interrupted sympathetic pathways.
47. INVASIVE TESTSINVASIVE TESTS
Done to locateDone to locate precise siteprecise site of pathologyof pathology
Done forDone for researchresearch purposepurpose
Intraneural recordingIntraneural recording of post-ganglionicof post-ganglionic
sympathetic activitysympathetic activity
ElicitingEliciting axon reflexaxon reflex by intradermal injection ofby intradermal injection of
acetyl-cholineacetyl-choline
Response of ANS to infusion ofResponse of ANS to infusion of pressor drugspressor drugs ::
injection or epinephrine(1 : 1000) in conjunctival sacinjection or epinephrine(1 : 1000) in conjunctival sac
Cocaine (4 to 10%) topical applicationCocaine (4 to 10%) topical application
Ephedrine testEphedrine test
Atropine testAtropine test
Neostigmine testNeostigmine test
48. OTHER TESTSOTHER TESTS
Measurement of skinMeasurement of skin temperaturetemperature
Tests forTests for sudomotorsudomotor functionfunction
Weight of sweatWeight of sweat
Galvanic skin resistance testGalvanic skin resistance test
Tests forTests for lacrimallacrimal functionfunction
Tests forTests for bladder and GITbladder and GIT dysfunctiondysfunction
LaboratoryLaboratory teststests
Measure plasma levels of catecholamines and other vasoactiveMeasure plasma levels of catecholamines and other vasoactive
hormones like renin, angiotensin and vasopressinhormones like renin, angiotensin and vasopressin
Measurement of forearm blood flow with plethysmographyMeasurement of forearm blood flow with plethysmography
Cerebral EEG blood flow studiesCerebral EEG blood flow studies
SELECTION OF TESTSSELECTION OF TESTS ::
To assess ANS involvement, 5 simple non-invasive tests areTo assess ANS involvement, 5 simple non-invasive tests are
sufficientsufficient
To assess definitive abnormality, 2 or more specific tests areTo assess definitive abnormality, 2 or more specific tests are
recommendedrecommended
49. ANAESTHESIA AND AUTONOMICANAESTHESIA AND AUTONOMIC
NERVOUS SYSTEMNERVOUS SYSTEM
GENERAL ANAESTHESIAGENERAL ANAESTHESIA
Pre medicationPre medication ::
Agents used to decrease secretions likeAgents used to decrease secretions like
atropine,glycopyrolate areatropine,glycopyrolate are anti cholinergicsanti cholinergics
Antiemetic metoclopramide is aAntiemetic metoclopramide is a dopaminergicdopaminergic
anti emeticanti emetic
Opiods cause respiratory depression byOpiods cause respiratory depression by
inhibiting Ach release from CNSinhibiting Ach release from CNS
Morphine releases histamine, venous pooling,Morphine releases histamine, venous pooling,
reduced peripheral vascular resistancereduced peripheral vascular resistance
50. Pentazocine increases plasma catecholaminesPentazocine increases plasma catecholamines
Fentanyl causes vagal bradycardia during intubationFentanyl causes vagal bradycardia during intubation
Beta antagonistsBeta antagonists reduce stress response during intubationreduce stress response during intubation
Alpha2 agonist,Alpha2 agonist, clonidine,clonidine, reduces dose of induction agent andreduces dose of induction agent and
stress response duringstress response during
Induction agents –
All induction agents except ketamine reduce sympathetic
activity
Arterial pressure drops
Baroreceptor mediated tachycardia may/may not occur
Ketamine stimulates the sympathetic system
Etomidate is a potent inhibitor of adrenergic
steroidogenesis
51. Inhalational AgentsInhalational Agents ––
Halothane, enflurane, isoflurane reduce pre-ganglionicHalothane, enflurane, isoflurane reduce pre-ganglionic
sympathetic activity and hence decrease plasmasympathetic activity and hence decrease plasma
catecholaminescatecholamines
Cyclopropane and diethyl ether increase sympatheticCyclopropane and diethyl ether increase sympathetic
activity by central action and by action on vasomotoractivity by central action and by action on vasomotor
neurons in spinal cordneurons in spinal cord
Muscle RelaxantsMuscle Relaxants ––
Pancuronium releases adrenaline and raises HR and BPPancuronium releases adrenaline and raises HR and BP
Autonomic changes like decreasingAutonomic changes like decreasing
arterial BP,HR and plasmaarterial BP,HR and plasma
catecholamines and cortisol indicatecatecholamines and cortisol indicate
increasing depth of anaesthesiaincreasing depth of anaesthesia
52. SPINAL ANAESTHESIASPINAL ANAESTHESIA
Causes sympathetic blockade, hypotension andCauses sympathetic blockade, hypotension and
bradycardia depending on the level of blockadebradycardia depending on the level of blockade
53. • In low SAB sacral parasympathetic and lumbar plusIn low SAB sacral parasympathetic and lumbar plus
lower thoracic sympathetics are blocked,lower thoracic sympathetics are blocked, uninhibited vagaluninhibited vagal
parasympathetics acting on splanchnic bed and visceraparasympathetics acting on splanchnic bed and viscera
In high SAB,In high SAB, all sympathetics are blockedall sympathetics are blocked, vagal, vagal
parasympathetics to thoracic and abdominal visceraparasympathetics to thoracic and abdominal viscera
become over active and cause severe bradycardia andbecome over active and cause severe bradycardia and
even asystoleeven asystole
InIn saddle blocksaddle block sacral parasympathetic is blocked,sacral parasympathetic is blocked,
thoracolumbar sympathetic is intact…causing minimalthoracolumbar sympathetic is intact…causing minimal
physiologic disturbancephysiologic disturbance
54. Features of Autonomic Imbalance afterFeatures of Autonomic Imbalance after
Spinal AnaesthesiaSpinal Anaesthesia
CVSCVS
HypotensionHypotension
BradycardiaBradycardia
GITGIT
Increased peristalsisIncreased peristalsis
Intestines usually activeIntestines usually active
RSRS
In high SAB(upper 5 or 6 thoracic sympathetic)In high SAB(upper 5 or 6 thoracic sympathetic)
Some bronchial spasm due to increased vagal activitySome bronchial spasm due to increased vagal activity
EPIDURAL ANAESTHESIAEPIDURAL ANAESTHESIA
Less hypotensionLess hypotension
SegmentalSegmental type of anaesthesia is possibletype of anaesthesia is possible
Onset of action is slowerOnset of action is slower
Hence compensatory mechanisms initiated well in advanceHence compensatory mechanisms initiated well in advance
55. Autonomic reflexes duringAutonomic reflexes during
Anaesthesia and SurgeryAnaesthesia and Surgery
Oculocardiac reflexOculocardiac reflex ::
Pressure over eyeballs or traction of externalPressure over eyeballs or traction of external
ocular musclesocular muscles
Causes bradycardia, asystole, cardiacCauses bradycardia, asystole, cardiac
dysrhytthmia, ventricular fibrillationdysrhytthmia, ventricular fibrillation
Light plane on anaesthesia, hypoxia,Light plane on anaesthesia, hypoxia,
hypercarbia aggravate this reflexhypercarbia aggravate this reflex
Prophylaxis with anticholinergics..still aProphylaxis with anticholinergics..still a
controversycontroversy
56. Abdominal reflexAbdominal reflex ::
Due to stimulation of ANS by traction orDue to stimulation of ANS by traction or
pressure during surgeries within the abdominalpressure during surgeries within the abdominal
cavitycavity
Circulatory effect – bradycardia, hypotentionCirculatory effect – bradycardia, hypotention
Respiratory effect – apnea, tachypnea,Respiratory effect – apnea, tachypnea,
laryngospasmlaryngospasm
These are :These are :
• Peritoneal and mesentericPeritoneal and mesenteric reflexreflex
• Coeliac plexusCoeliac plexus reflex – traction of stomach,gallreflex – traction of stomach,gall
bladder, hilum of liver or retraction of duodenumbladder, hilum of liver or retraction of duodenum
• Brewer LuckhardtBrewer Luckhardt reflex/ Diaphragmatic tractionreflex/ Diaphragmatic traction
reflexreflex
• Reflexes associated with pelvic nerveReflexes associated with pelvic nerve
57. Recto – laryngeal reflexRecto – laryngeal reflex ::
Caused by dilation of anal sphincter under GACaused by dilation of anal sphincter under GA
Afferent is via pelvic and sacral nerve toAfferent is via pelvic and sacral nerve to vagalvagal motormotor
nucleusnucleus
Efferent is viaEfferent is via recurrent laryngealrecurrent laryngeal nervenerve
Causes laryngeal spasm and apneaCauses laryngeal spasm and apnea
Recto – cardiac reflexRecto – cardiac reflex ::
Anal sphincter dilation causes bradycardia, hypotensionAnal sphincter dilation causes bradycardia, hypotension
Preventions :Preventions :
These autonomic reflexes can be prevented by adequateThese autonomic reflexes can be prevented by adequate
depth of anaesthesiadepth of anaesthesia
Atropine prophylaxis maybe givenAtropine prophylaxis maybe given
Ask surgeon to avoid manipulations, proceed gently andAsk surgeon to avoid manipulations, proceed gently and
slowlyslowly
58. ANS DYSFUNCTIONANS DYSFUNCTION
PRIMARY –PRIMARY –
Idiopathic orthostatic hypotensionIdiopathic orthostatic hypotension
Shy Dragger syndromeShy Dragger syndrome
FAMILIAL –
Riley Day syndrome
Leesch Neehan syndrome
•Genetic disorder of purine metabolism in
males
•Sympathetic response to stress is
enhanced
Gill Familia dysautonomia
60. AGINGAGING
20% of people over 65yrs have20% of people over 65yrs have postural hypotensionpostural hypotension
Symptoms – dizziness, faintness, loss of consciousnessSymptoms – dizziness, faintness, loss of consciousness
Selective/Selective/ early parasympatheticearly parasympathetic involvementinvolvement
Delayed/ slow sympathetic involvementDelayed/ slow sympathetic involvement
Blunting of – Vasalva maneuverBlunting of – Vasalva maneuver
Respiratory cycleRespiratory cycle
HR changes to changes in BPHR changes to changes in BP
Resting and exercise induced NE responseResting and exercise induced NE response
61. ALCOHOLISMALCOHOLISM
Acute, chronic or alcohol withdrawal causes orthostaticAcute, chronic or alcohol withdrawal causes orthostatic
intoleranceintolerance
Poor nutrition impairs SNSPoor nutrition impairs SNS
Baroreceptors less sensitiveBaroreceptors less sensitive
Vasalva ratio and cardiac acceleration following ivVasalva ratio and cardiac acceleration following iv
atropine is diminished in presence of neurologicalatropine is diminished in presence of neurological
impairmentimpairment
62. TETANUSTETANUS
Sympatho adrenalSympatho adrenal
hyperactivity is thehyperactivity is the
chief cause of deathchief cause of death
Direct effect ofDirect effect of
tetanus toxin on SNStetanus toxin on SNS
causes rise in plasmacauses rise in plasma
catecholaminescatecholamines
63. PHEOCHROMOCYTOMAPHEOCHROMOCYTOMA
Catecholamine secreting tumourCatecholamine secreting tumour
Hypertension, hypermetabolism, hyperglycemiaHypertension, hypermetabolism, hyperglycemia
Preop alpha blockers are given toPreop alpha blockers are given to
Restore blood volumeRestore blood volume
Assess end organ damageAssess end organ damage
Treat cardiac arrhythmiasTreat cardiac arrhythmias
64. GUILLIAN BARREGUILLIAN BARRE
SYNDROMESYNDROME
• ANS involvementANS involvement
secondary tosecondary to axonalaxonal
degenerationdegeneration
• Variable BP, facialVariable BP, facial
flushing, urinaryflushing, urinary
retention, tachy –retention, tachy –
brady arrhythmiasbrady arrhythmias
• Neuropathic lesions inNeuropathic lesions in
afferent limb ofafferent limb of
baroreceptor may leadbaroreceptor may lead
toto SIADH,SIADH,
hyponatremiahyponatremia
65. Neuronal degenerationNeuronal degeneration
Metabolically related neuronalMetabolically related neuronal
dysfunctiondysfunction
Afferent, central and efferentAfferent, central and efferent
pathways involvedpathways involved
Vagal neuropathyVagal neuropathy occurs beforeoccurs before
systemic neuropathysystemic neuropathy
Symptomatic posturalSymptomatic postural
hypotension implies poorhypotension implies poor
prognosisprognosis
Esophageal gastric hypomotility,Esophageal gastric hypomotility,
bradycardia, silent myocardialbradycardia, silent myocardial
infarcts, impaired ventilatoryinfarcts, impaired ventilatory
control, unexplained cardiocontrol, unexplained cardio
respiratory arrests may occurrespiratory arrests may occur
66. AUTONOMIC CHANGES IN SPINALAUTONOMIC CHANGES IN SPINAL
CORD TRANSECTIONCORD TRANSECTION
Affects motor, sensory and ANS depending on level of transectionAffects motor, sensory and ANS depending on level of transection
Acute effects/Acute effects/ Spinal ShockSpinal Shock ::
Flaccid paralysisFlaccid paralysis
Total absence of sensationTotal absence of sensation
Loss of temperature regulationLoss of temperature regulation
Loss of spinal reflexes below level of injuryLoss of spinal reflexes below level of injury
Decreased systolic BPDecreased systolic BP
BradycardiaBradycardia
Abnormal ECG, ST-T changes, VPCsAbnormal ECG, ST-T changes, VPCs
67. Management of Anaesthesia :Management of Anaesthesia :
• AirwayAirway managementmanagement
• Avoidance ofAvoidance of hypovolemiahypovolemia
Anaesthesia is given so that pt. toleratesAnaesthesia is given so that pt. tolerates
tubetube
Muscle relaxant is used as neededMuscle relaxant is used as needed
68. ANAESTHESIA IN PATIENTS WITH ANSANAESTHESIA IN PATIENTS WITH ANS
DYSFUNCTIONDYSFUNCTION
UnderstandUnderstand the impactthe impact
Reduced ANS activity on CVSReduced ANS activity on CVS
responses to change inresponses to change in
o body positionbody position
o positive airway pressurepositive airway pressure
o acute blood lossacute blood loss
o effects due to negativeeffects due to negative
inotropic anaesthetic agentsinotropic anaesthetic agents
PosturePosture – shift patient to OT– shift patient to OT
and induce in supine positionand induce in supine position
PreloadingPreloading should be doneshould be done
properlyproperly
Pre medicationPre medication ––
Atropine may fail to produceAtropine may fail to produce
tachycardiatachycardia
Ranitidine and metoclopramideRanitidine and metoclopramide
to avoid regurg and aspirationto avoid regurg and aspiration
Narcotics and other respiratoryNarcotics and other respiratory
depressants are avoideddepressants are avoided
MonitoringMonitoring ––
Pulse oxPulse ox
Continuous arterial BPContinuous arterial BP
ECGECG
CVPCVP
TemperatureTemperature
Urine outputUrine output
69. GENERAL ANAESTHESIAGENERAL ANAESTHESIA
InductionInduction ––
Thiopentone given slowly with proper iv fluidThiopentone given slowly with proper iv fluid
replacementreplacement
Diazepam and fentanyl may also be usedDiazepam and fentanyl may also be used
Ketamine produces accentuated BP responseKetamine produces accentuated BP response
Rapid sequence intubationRapid sequence intubation as patients haveas patients have
gastro-paresisgastro-paresis
Maintenance on spontaneous breathing withMaintenance on spontaneous breathing with
N2O and O2, withN2O and O2, with minimal halothaneminimal halothane
If needed, cardio stable muscle relaxants likeIf needed, cardio stable muscle relaxants like
Vec should be usedVec should be used
70. IPPV produces exaggerated reduction inIPPV produces exaggerated reduction in
BPBP
Blood loss should be replaced promptly asBlood loss should be replaced promptly as
compensatory tachycardia is absentcompensatory tachycardia is absent
Volatile anaesthetics produce excessiveVolatile anaesthetics produce excessive
myocardial depression and hypotensionmyocardial depression and hypotension
Maintain fluid balanceMaintain fluid balance
Avoid hypothermiaAvoid hypothermia (pts may become(pts may become
poikilothermic due to sympatheticpoikilothermic due to sympathetic
dysfunction)dysfunction)
Vasopressors should be used with cautionVasopressors should be used with caution
71. REGIONAL ANAESTHESIAREGIONAL ANAESTHESIA
Risk of hypotension with SAB andRisk of hypotension with SAB and
epiduralsepidurals
Post spinal urinary retention may occurPost spinal urinary retention may occur
Pre opPre op presence ofpresence of impotenceimpotence must bemust be
brought to notice to avoidbrought to notice to avoid medico legalmedico legal
implicationsimplications
72. ANS IN INTENSIVE CAREANS IN INTENSIVE CARE
Mechanical IPPVMechanical IPPV causes increased intra thoraciccauses increased intra thoracic
pressure, decreased cardiac filling and hence,pressure, decreased cardiac filling and hence,
decreased cardiac outputdecreased cardiac output
All reflex mechanisms fail hence cardiac output fallsAll reflex mechanisms fail hence cardiac output falls
drasticallydrastically
Suction careSuction care
74. LUMBAR SYMPATHETIC BLOCKLUMBAR SYMPATHETIC BLOCK
Used to alleviate theUsed to alleviate the rest pain of chronic PVDrest pain of chronic PVD
Preganglionic sympathetics are from lowerPreganglionic sympathetics are from lower
thoracic chain and pre ganglionic somatic fibresthoracic chain and pre ganglionic somatic fibres
are from 1are from 1stst
and 2and 2ndnd
lumbar nerveslumbar nerves
Post ganglionic fibres are vasoconstrictor toPost ganglionic fibres are vasoconstrictor to
arterioles, pilomotor and sudomotor to skinarterioles, pilomotor and sudomotor to skin
Hence, its block causes absence of sweatingHence, its block causes absence of sweating
and warm dry skinand warm dry skin
75. COELIAC PLEXUS BLOCKCOELIAC PLEXUS BLOCK
Used for intractable pain caused byUsed for intractable pain caused by
cancer of pancreas, stomach, gall bladdercancer of pancreas, stomach, gall bladder
and liverand liver
SUPERIOR HYPOGASTRIC PLEXUSSUPERIOR HYPOGASTRIC PLEXUS
BLOCKBLOCK
Relates pain from pelvic organsRelates pain from pelvic organs
Used in cancer pain due toUsed in cancer pain due to
cervical,prostate,testicular cancers and incervical,prostate,testicular cancers and in
radiation injuryradiation injury
76. COMPLEX REGIONAL PAIN SYNDROMECOMPLEX REGIONAL PAIN SYNDROME
Consequence of limb trauma with orConsequence of limb trauma with or
without obvious nerve lesionswithout obvious nerve lesions
Characterised by motor, sensory and ANSCharacterised by motor, sensory and ANS
symptomssymptoms
ANS features include abnormal skin bloodANS features include abnormal skin blood
flow, temperature and sweatingflow, temperature and sweating
PHANTOM LIMBPHANTOM LIMB
Ectopic discharge ofEctopic discharge of epinephrine from a stump neuromaepinephrine from a stump neuroma isis
an important peripheral mechanisman important peripheral mechanism
Sympathetic block, sympathectomies or beta blockersSympathetic block, sympathectomies or beta blockers
increase blood flow and reduce intensity of burning painincrease blood flow and reduce intensity of burning pain
Decreased blood flow causes phantom limb painDecreased blood flow causes phantom limb pain
77. CONCLUSIONCONCLUSION
ANS plays a very dominant role in maintainingANS plays a very dominant role in maintaining
haemodynamic stabilityhaemodynamic stability
Influences the outcome after anaesthesia and surgeryInfluences the outcome after anaesthesia and surgery
