Mekanisme Anestesi Inhalasi

7/24/2019 Mekanisme Anestesi Inhalasi

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MekanismeAnestesiInhalasi







onsentrasi uap anestetik dalam alveoliselama induksi ditentukan oleh:

1. konsentrasi inspirasi

2.ventilasi alveolar

3. koesien darah!gas

". hubungan ventilasi#perfusi



A$I A%$'$I I%(A)A$I*A+A $I$'M $A,A- *$A'

1. Medulla spinalis

Immobilisasi terhadap rangsangan nyeri

As/ending signals from the spinal /orda0e/t the hypnoti/ a/tions ofanestheti/s in the brain hereasdes/ending signals modify the

immobiliing a/tions of anestheti/s inthe spinal /ord



2. 4tak

Above the spinal /ord inhaled agentsglobally depress blood 5o and glu/osemetabolism and sele/tively depressseveral supraspinal regions

Although there is no denitive eviden/e

that spe/i/ regions of the brain aretargets of inhaled anestheti/s attentionhas fo/used on stru/tures ith roles inanestheti/#sensitive fun/tions. 'hereti/ular# a/tivating system thalamus

pons amygdala and hippo/ampus areinvolved in /ognition memory learningsleep and attentiveness



,e/ent studies impli/ate the

tuberomammilary nu/leus a 6A7A#modulated region of the hypothalamusthat is linked to sleep states in thesedative a/tions of some intravenouslyadministered general anestheti/s andperhaps inhaled agents.

n/oupling of /oherent anteroposteriorand interhemispheri/al ele/tri/al a/tivityis /onsistently asso/iated ith anestheti/#

indu/ed un/ons/iousness



Aksi Molekular AnestesiInhalasi

*rotein $ites

Intera/t ith small /avities ithin most

globular proteins but ith /onsiderablesele/tivity

Anestheti/s alter the fun/tions of a variety of/ytoplasmi/ signaling proteins in/luding

protein kinase 8. %evertheless the proteins/onsidered the most likely mole/ular targetsof anestheti/s are ion /hannels.



fek anestesi padaion

channels

Ion /hannels proteins that regulate the 5oof ions a/ross the /ytoplasmi/ membrane

Ion /hannels that are sensitive to volatileanestheti/s at /lini/ally e0e/tive/on/entrations in/lude both the superfamilyof 9/ysteineloop neurotransmitter re/eptorshi/h in/ludes ni/otini/ a/etyl/holineserotoni type 3 6A7A A and gly/inere/eptors and the glutamate re/eptors thatare a/tivated by N ;methyld #aspartate<%M+A= or a #amino#3#hydro>y#?#methyl#"#iso>aolepropioni/ a/id <AM*A=



@ithin synapses ion /hannels /anin5uen/e the presynapti/ release ofneurotransmitters and alterpostsynapti/ e>/itability in response tothe release of neurotransmitters.oltage#gated ion /hannels for sodium

potassium and /al/ium are alsosensitive to some inhaled anestheti/salbeit usually a /on/entrations higherthan those used /lini/ally.



@orking hypothesis inhaled anestheti/s

enhan/e inhibitor postsynapti/ /hannela/tivity <6A7A A and gly/ine re/eptors= andinhibit e>/itatory synapti/ /hannel a/tivit<ni/otini/ a/etyl/holine serotonin andglutamate re/eptors=

At /lini/ally e0e/tive /on/entrations generalanestheti/s in/rease the apparent sensitivityof re/eptors to 6A7A and prolong there/eptor#mediated inhibitory /urrent after a

pulse of 6A7A release. 'his augments 6A7AA#re/eptor;mediated inhibition ofpostsynapti/ neuronal e>/itability



'he important e0e/ts of inhaled anestheti/s

are produ/ed at di0erent /on/entrations 'he ablation of e>pli/it memory and

responsiveness to a spoken /ommand<hypnosis= are produ/ed at anestheti//on/entrations loer than those that

prevent movement in response to surgi/alin/ision hereas the blo/kade of autonomi/responses to pain reBuires very deepanesthesia. $ensitivity to inhaledanestheti/s varies from person to person

and the steepness of the /on/entration;response /urves re5e/ts the distribution ofindividual responses





+istin/t ion /hannels may mediate

di0erent behavioral and physiologi/ale0e/ts of inhaled anestheti/s. %euronalni/otini/ a/etyl/holine re/eptors areinhibited by inhaled anestheti/s at lo

/on/entrations that /ause amnesia butnot immobility as ell as by the volatilenonimmobiliers. Anestheti/ inhibition ofthese re/eptors most likely impairsmemory and learning but not immobility.



7e/ause ion /hannels fun/tion ithin lipid

membranes it is diC/ult to dis/ern hethertheir modulation by anestheti/s is /ausedindire/tly by /hanges in membrane stru/tureor dire/tly by binding to protein sites

'he neuronal fun/tions underlying netorka/tivity are a>onal /ondu/tion and synapti/transmission. 8lini/al /on/entrations ofinhaled anestheti/s a0e/t the latter mu/hmore than the former. Inhaled anestheti/s

both depress e>/itatory synapses andaugment inhibitory synapses.



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Mekanisme Anestesi Inhalasi