ppt shiver
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anestesiTRANSCRIPT
2003/11/26 Chih-Min Liu 1
Postanesthetic Postanesthetic ShiveringShivering
Epidemiology, Epidemiology, Pathophysiology, Prevention Pathophysiology, Prevention
and Managementand Management
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ReferenceReference
Perioperative ShiveringPerioperative Shivering Physiology and PharmacologyPhysiology and Pharmacology
Anesthesiology 2002; 96: 467-84Anesthesiology 2002; 96: 467-84 Postanesthetic ShiveringPostanesthetic Shivering
Epidemiology, Pathphysiology, and Epidemiology, Pathphysiology, and Approaches to Prevention and Approaches to Prevention and ManagementManagement Drugs 2001; 61 (15): 2193-2205Drugs 2001; 61 (15): 2193-2205
Clinical Anesthesiology, third editionClinical Anesthesiology, third edition Chapter 6: Patient monitors; 117-120Chapter 6: Patient monitors; 117-120
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Clinical ConsiderationsClinical Considerations Hypothermia: < 36 Hypothermia: < 36 ooCC OO22 consumption x 5; decrease saturation; consumption x 5; decrease saturation;
myocardial ischemia and angina myocardial ischemia and angina Increased mortality rateIncreased mortality rate Monitoring site:Monitoring site:
Tympanic membrane: brain temperatureTympanic membrane: brain temperature Nasopharyngeal mucosa: core temperatureNasopharyngeal mucosa: core temperature Rectum: slow response in change to core Rectum: slow response in change to core
temptemp Esophagus Esophagus
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EpidemiologyEpidemiology 40-60% after volatile anesthetics40-60% after volatile anesthetics Young male adult, rare in elder (age impairs Young male adult, rare in elder (age impairs
thermoregulatory control)thermoregulatory control) Length of anesthesia or surgeryLength of anesthesia or surgery Peri-op rewarming procedure: if notPeri-op rewarming procedure: if not Mild hypothermia Mild hypothermia
The more serious hypothermia, the higher the The more serious hypothermia, the higher the probabilityprobability
Anesthetic used Anesthetic used Less common with propofol; more with halogenated Less common with propofol; more with halogenated
agent, pentothalagent, pentothal
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Pathophysiology Pathophysiology
Consequence of postanesthetic Consequence of postanesthetic shiveringshivering DiscomfortDiscomfort Increased painIncreased pain IICP, IOPIICP, IOP OO22 consumption (VO consumption (VO22): more 40 ): more 40 –– 120% 120% Increased minute ventilationIncreased minute ventilation Cardiac morbidityCardiac morbidity
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Pathophysiology Pathophysiology
Two types of postanesthetic Two types of postanesthetic shiveringshivering Thermoregulated shiveringThermoregulated shivering
With cutaneous vasoconstriction, the With cutaneous vasoconstriction, the response of hypothermiaresponse of hypothermia
Perioperative hypothermiaPerioperative hypothermia Non-thermoregulated shiveringNon-thermoregulated shivering
Mechanism unknownMechanism unknown Postoperative pain related?Postoperative pain related?
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Pathophysiology Pathophysiology
Origins of Postanesthetic ShiveringOrigins of Postanesthetic Shivering Perioperative hypothermiaPerioperative hypothermia Postoperative painPostoperative pain Perioperative heat lossPerioperative heat loss Direct effect of certain anestheticsDirect effect of certain anesthetics Hypercapnia or respiratory alkalosisHypercapnia or respiratory alkalosis The existence of pyogensThe existence of pyogens HypoxiaHypoxia Early recovery of spinal reflex activityEarly recovery of spinal reflex activity Sympathetic overactivity Sympathetic overactivity
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Perioperative Perioperative hypothermiahypothermia
32.5
33
33.5
34
34.5
35
35.5
36
36.5
37
37.5
0 1 2 3 4 5
Temp
Phase I: 1st hourPhase I: 1st hour Internal Internal
redistribution: from redistribution: from center to peripheral center to peripheral
Phase II: 2-4 hoursPhase II: 2-4 hours Heat loss: skin, Heat loss: skin,
visceraviscera Phase III: Phase III:
Steady-stateSteady-state
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Pathophysiology Pathophysiology
Early recovery of spinal reflex Early recovery of spinal reflex activityactivity Residual effect of anesthetics on the Residual effect of anesthetics on the
inhibiting control exercised by inhibiting control exercised by supraspinal structuresupraspinal structure
Propofol in low concentration may have Propofol in low concentration may have less effect on certain central structure less effect on certain central structure such as the reticular formation, thus such as the reticular formation, thus faster recovery of descending inhibiter faster recovery of descending inhibiter controlcontrol
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Temperature-regulating Temperature-regulating systemsystem
ThermosensorsThermosensors Skin to hypothalamusSkin to hypothalamus
Afferent pathway, Afferent pathway, integration areaintegration area
Spinal cordSpinal cord Modulate: Modulate:
NRM( serotonin), LS(NE)NRM( serotonin), LS(NE) Integration inputs: PO-Integration inputs: PO-
AHAH Efferent pathwayEfferent pathway
Central descending Central descending shivering pathway: PHshivering pathway: PH
Multiple inputs>common Multiple inputs>common efferent signalefferent signal
Spinal Spinal αα motor neurons, motor neurons, axonsaxons
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PathophysiologyPathophysiology
Human defenses to hypothermia:Human defenses to hypothermia: Skin vasomotor activitySkin vasomotor activity Nonshivering thermogenesisNonshivering thermogenesis
Cell metabolic without mechanical work, Cell metabolic without mechanical work, NeonateNeonate
ShiveringShivering Sweating Sweating
Shivering is the last-resort defense Shivering is the last-resort defense
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PathophysiologyPathophysiology Shivering Shivering
Several typesSeveral types 4-8 Hz., waxing-and-waning pattern4-8 Hz., waxing-and-waning pattern
Postanesthetic tremorPostanesthetic tremor Thermoregulatory inhibition abruptly Thermoregulatory inhibition abruptly
dissipates, thus increasing the shivering dissipates, thus increasing the shivering threshold toward normalthreshold toward normal
New, near-normal threshold activate New, near-normal threshold activate shiveringshivering
Shivering like activityShivering like activity Pain in post-op and labor femalePain in post-op and labor female
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Prevention & Prevention & ManagementManagement
Perioperative Hypothermia PreventionPerioperative Hypothermia Prevention Limiting the effects of internal redistributionLimiting the effects of internal redistribution
Skin surface rewarming with Skin surface rewarming with forced-air warmerforced-air warmer for 30 minutes for 30 minutes
Reduce heat lossReduce heat loss Radiation from skin surfaceRadiation from skin surface Room temperature > 23Room temperature > 23ooC if the op field is largeC if the op field is large Cover the patient as much as possibleCover the patient as much as possible
Intravenous fluid rewarmingIntravenous fluid rewarming
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Prevention & Prevention & ManagementManagement
Passive prevention is not enoughPassive prevention is not enough Active heat transfer Active heat transfer
Cutaneous patchCutaneous patch is the most efficient is the most efficient Forced warm airForced warm air better then better then…… Water circulation blanketsWater circulation blankets
1/3 cover of the cutaneous surface is 1/3 cover of the cutaneous surface is enoughenough
Under GA > vasodilatation > heat lossUnder GA > vasodilatation > heat loss
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Prevention & Prevention & ManagementManagement
Physical treatmentPhysical treatment Shivering threshold: Shivering threshold:
skin 20%, core 80% skin 20%, core 80% Raise temp to inhibit postoperative Raise temp to inhibit postoperative
shivering: shivering: skin 4skin 4ooC = core 1C = core 1ooCC
Radiation heat systemRadiation heat system Forced air warmer: Forced air warmer:
reduce frequency and duration of shiveringreduce frequency and duration of shivering
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Prevention & Prevention & ManagementManagement
Medical treatmentMedical treatment OpiatesOpiates Tramadol, Ketanserin, Nefopam and Tramadol, Ketanserin, Nefopam and
OndensetronOndensetron αα2-Adrenergic Agonists2-Adrenergic Agonists Other drugsOther drugs
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Opiates Opiates MeperidineMeperidine
DemoralDemoral ΚΚ-opioid receptor-opioid receptor Shivering thresholdShivering threshold VasoconstrictionVasoconstriction Sweating Sweating
Others:Others: Pure Pure μμ-receptor agonists-receptor agonists Morphine, alfentanyl, fentanylMorphine, alfentanyl, fentanyl
Sites of actionSites of action PO-AH, dorsal raphe nucleus neurons, RMN, PO-AH, dorsal raphe nucleus neurons, RMN,
LS, and the spinal cordLS, and the spinal cord
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Meperidine( Demoral) Meperidine( Demoral)
SweatingSweating VasoconstrictionVasoconstriction Shivering Shivering
thresholdthreshold
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Tramadol, Ketanserin, Tramadol, Ketanserin, Nefopam and OndensetronNefopam and Ondensetron
The The balancebalance of Norepinephrine and of Norepinephrine and serotonin(5-HT) in the PO-AH controls the body serotonin(5-HT) in the PO-AH controls the body temperature set pointtemperature set point
5-HT induce hyperthermia; 5-HT induce hyperthermia; αα2-Adrenergic 2-Adrenergic Agonists (clonidine) reduce core temperatureAgonists (clonidine) reduce core temperature
Opposite modulatory inputs from NE and Opposite modulatory inputs from NE and serotonergic neurons shifting the shivering serotonergic neurons shifting the shivering thresholdthreshold
All 4 drugs acts on the serotonin neuromediatorAll 4 drugs acts on the serotonin neuromediator Encourage the inhibiting effect of serotonin on Encourage the inhibiting effect of serotonin on
OP-AHOP-AH
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Tramadol, Ketanserin, Tramadol, Ketanserin, Nefopam and OndensetronNefopam and Ondensetron
TramadolTramadol Inhibits reuptake of 5-HT, NE, dopamine and facilitate 5-HT Inhibits reuptake of 5-HT, NE, dopamine and facilitate 5-HT
release release Site of action: PonsSite of action: Pons Analgesic effect, non-opioid analgesicAnalgesic effect, non-opioid analgesic 1 mg/kg for shivering, reduce threshold by 0.81 mg/kg for shivering, reduce threshold by 0.8ooCC
Nefopam Nefopam Inhibits reuptake of 5-HT, NE, dopamine and lower normal Inhibits reuptake of 5-HT, NE, dopamine and lower normal
body temperaturebody temperature Analgesic effect, 0.15mg/kg or 20mgAnalgesic effect, 0.15mg/kg or 20mg
Ketanserin Ketanserin Low efficacyLow efficacy Antihypertensive effect, 5 HTAntihypertensive effect, 5 HT22 antagonist, 10mg antagonist, 10mg
OndensetronOndensetron Antiemetic, 5 HTAntiemetic, 5 HT33 antagonist, 8mg antagonist, 8mg
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αα2-Adrenergic Agonists2-Adrenergic Agonists Clonidine 75Clonidine 75μμg g
lower the threshold of cutaneous lower the threshold of cutaneous vasoconstriction and shivering by 0.5vasoconstriction and shivering by 0.5ooCC
Bolus & perfusion: Bolus & perfusion: At the end of op: 1.5 or 3At the end of op: 1.5 or 3μμg/kgg/kg Cardiac surgery: 200 to 300Cardiac surgery: 200 to 300μμgg
Mechanism: Mechanism: CentralCentral Shivering centre is under inhibiting control of Shivering centre is under inhibiting control of
the preoptic anterior hypothalamic regionthe preoptic anterior hypothalamic region αα2-Adrenergic Agonists probably strengthened it 2-Adrenergic Agonists probably strengthened it
DexmedetomidineDexmedetomidine
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Other drugsOther drugs Other drugsOther drugs
NMDA receptor antagonist: NMDA receptor antagonist: Ketamine Ketamine Magnesium sulfate 30mg/kgMagnesium sulfate 30mg/kg
Methylphenidate 20mg Methylphenidate 20mg Analeptic agent, block reuptake of 5-HTAnaleptic agent, block reuptake of 5-HT
Physostigmine 0.04mg/kgPhysostigmine 0.04mg/kg Central acting cholinesterase inhibitorCentral acting cholinesterase inhibitor
Doxapram 100mg or 1.5mg/kgDoxapram 100mg or 1.5mg/kg Respiratory stimulant, central action on ponsRespiratory stimulant, central action on pons
Recovery of the descending inhibitor control of Recovery of the descending inhibitor control of the supraspinal effecting centersthe supraspinal effecting centers
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Conclusion Conclusion Hypothermia is associated with shivering and many Hypothermia is associated with shivering and many
complications, patient should be kept normothermiacomplications, patient should be kept normothermia Prevention of hypothermia consists of limiting heat loss Prevention of hypothermia consists of limiting heat loss
and active rewarming systemand active rewarming system Effective treatment of shivering will reduce metabolic heat Effective treatment of shivering will reduce metabolic heat
production and must be accompanied by an effective active production and must be accompanied by an effective active heating system.heating system.
Skin surface rewarming is less efficient then medical Skin surface rewarming is less efficient then medical treatment with meperidine, tramadol, or, in certain treatment with meperidine, tramadol, or, in certain situations, clonidinesituations, clonidine
All antishivering drugs except ketanserin have some All antishivering drugs except ketanserin have some analgesic properties in humans, suggested that pain and analgesic properties in humans, suggested that pain and thermoregulation are tightly connectedthermoregulation are tightly connected
No single structure or pathway is responsible for the No single structure or pathway is responsible for the shivering responseshivering response
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Thanks for your Thanks for your attention attention