Tài liệu ôn tập cho kỳ thi tuyển viên chức ngành y tế năm 2017 bai giang gay me hoi suc i file 2

Don g m a u nao CBF-cerebra l blood flow tan va co giam sue emach nao CRV- cerebral vascular resistanee d ap luc CO2 b !thuong, Ap luc mice nao tuy tang CFP:eerebral fluid pressurcjnhung

Cac thuoc gay me boc h i va thuoc me th~ khi d oc sU: dung bat am i\:voi ether ethylic (18 2) nita o yd (N20- 1844), chloroform (1~ t~;i;inhung do mot so dac tfnh bat IQi cua mot so thuoc nen ngay nay '::"I~dung nhu: chloroform de guy bong da va niern ma , ether d§ gay chi~"~

Tir narn 195 nguoi ta b&t dau dung mot so thuoc me boc h i mci '~J ld§.n x at halogen (Halogenated h drocarbons) bao g6m: halotha m: ~

1951), enfluran (cthrane - 1966), isofluran (forance, ncderane .;fuli 1~7 ) }ro~g d halothan la dan x at cua eth l con ca thuoc kia ~~i

,}!'t Halothan (fluothane) ten hoa hoc la 2-bromo - 2 _ chloro _ 1,1 v'

trifluoroethan, duoc phat hien tu 1951 boi C.W Suckling.

Corig thuc hoa hoc: C 2 F 3 HCIBr.

F-C-C-H

Cl

- Duoc nghien cuu ve duoc 15'b i James Raventos (1905-1983). D'

tron lam sang narn 1956 boi M.Johnstone (Manchester), sau de.:

Bryce-Smith va O'Brien 0 Oxford.

HALOTHAN

I.OAT VAN DE

II. oAc TfNH LY - HoA HQC

"

Halcthan Ia chat long khorig mau, vi n ot, mui de chiu, Trong ht

p an tv la 197,39 va trQng lu'c;Jn r eng 0 25°C la 1,87 Nhi~t d9 sci

5 °C ap h,IC hoi bao hoa d 20°C la 243 mmHg Cfin pha them th

0,01 % d~ 6n dinh du g dich "

Halothan b~ pha huy boi anh sang vi v~y phai gilt d 1Qthuy t nh

h phach Khi bi p an huy tC,lO ra m9t so acid HCI, HBr, Clo tlj do

phosgfm r;']t r1(lC va Bay h n may.

Halothan c6 th~ hoa tan cao tro g cao su, h~ so hoa tan cao su.J']

121,1 0 760mmHg, 24°C. Sv hap thu halothan b6i cao su nay

bien d6i dan k~ n6ng d9 cua halothan Wi b~nh nh8.n.

446

Halo t han 6 n dinh vci s u c6 ma t cua voi soda tu nhien n6 clin bi be gay

mot i (0,2%) tao than chat dOc CF' 2 + CBrCL 6n n dOgay me, h n ho

thuoc voi oxy kh6ng gaychat chay, n nen c6 th~ d n dao dien,

Halothan bi hap thu b21icac chat dco, cao S U o Phan ung h§.u het voi

cac kim 100.j, tu nhien d6n do voi cr6m kh6 g bi an man, kh6ng

p an u g vdi nikcn va titan

H~ so ph a n ly mau/khf =2,4, h~ so phan ly rno/rnau =60,0 nao/rnau =

2,6 Day la mot thuoc gay me manh

~: IIlI.TfNH CHAT oucc LY

Halothan dl<;JCphan phoi VaGcac Cd quan giau m0.ch mau nhu: nao,

tim, gaD, th~n, VaGCd,md, xudn it hd

N6n dO phe nang to'ithi6 (MAC) cho gay me 1a0,75% N6 g dOphe

nan nghla la n ng dOd CUo'ihi thd ra b&n voi n6ng dOd nao N6n

dOnay la mOt chi so'd~chi dO sau clla me MAC thay d6i theo tu i: d

tre sd sinh 1%dn u i gia h n 80 tu6i la 0,6 %

8\1thay d6i nay con ph\l thuOc VaGnhieu yeu to nhu Sv thay d i clla

cac t6 chue giau m0.ch mau, MAC giam khi thieu oxy, h0.huyet ap,

thieu mau, h0.nhi~t dO,do tien me hoac slt d\ln d6ng th i cac thuoc

d n hQ morphin hoi;le cac thuo'C me kha , vi dv khi slt dVn vSJi70%

nitd oxyd (proto ide d' ajote - N20, nid oxy , protoxi nitd) lam giam

MAC x ong con 0,29%

Sv khuyech tan nhanh ella halothan q a mang phe nang, Svhoa tan yeu

tt:lJn mau, sv tich luy eh~m tron md giai thich cho sv kh21ime nhanh, tinh

~nJn{lnh,d & ct.i~LLk i&n ct~)sfm ella me

,.

.

'.1 Tinh chat dL(<;5C Iy

~ 21 TaG d¢ng len th,!i'nkinh trung U'o' ng:

Halathan 1a mOt thuoc me m0.nh, kh6 g gay kich thich khi nglti va

hit, tan ch~m trong mau va nao, dieu d6 cho phep tich lu nhan ap

1vcrien ph§.n tron mau dOn m!';lchva nao va eu g vi the cho phep

dieu khi~n linh hO!';ltdO sau ella me va thoat me cu g nhan

Don g m a u nao (CBF-cerebra l blood flow) tan va co giam sue e

mach nao (CRV- cerebral vascular resistanee) d ap luc CO2 b !thuong),

Ap luc mice nao tuy tang (CFP:eerebral fluid pressurcjnhung co ::::phong n ua bang' each tan thong khi truce khi dung halothan

Halothan la thuoc thich hem d§ dat nQi khi quan khorig dung gian

(j trc em vi n kh o ri g co kha nang nguy hi6m cua S\I kieh thich :

thong than kinh trung u n

2.2 H¢ th6'ng h6 h,j'p:

Khi d ng halo than s1,1giam ho hap xay ra rat sam, ire ehe trung til

h hap sau trung tam van mach (mach gftp 3 Ian ether tire la 1_l~

cua halothan Hun giarn h hap bang 3 MAC (cua ether Halothan Hun giarn ve th6 tieh nhieu han la giarn toe dQh hap C:l

y eu lam g iarn ch c n{mg cu a cac eo lien siren, it han voi heat G.~ ocua eo hoan , vi vay khi co ho hap h6 tro hay h6 hap chi huy 8:0 !~dang gay me voi ha:lothan

Halothar lam giam philn X? h9ng va h~u, giam tiet mioe b9t va ~phe quan: Lam gian p e quan va ngUdi ta da chung minh duc.kIlam thay d i hoan toan khan n uyen gay ra co th~t phe quan (ehe bao g6m s1,1lam giam phan X? eua eae dUd g phe quan nho ~tae dQngtr1,1etiep len co trOll. Chuy~n hoa eua 5hydroxytryptaminjlie ehe trong ph i khi gay me v6i halothan, vi v~y halothan la ':trong cae L}woc dUc;Jel1,1aeh9n khi gay me b$nh nhan eo hen p!

q an Halothan eo kha nan lam giam eo q an nh~n earn hoa b~

n o?i vi C6 tae gia con eho r&n halo than kich thieh cac recep~adrenergie gay gian phe q an

Ngay d nong dQthap 0, 1 MAC halothan Hun giam nhieu s1,1phan is

th ng khi doi voi S1,1giam oxy trong khi thd vao (hypoxia), trong !j

rna s1,1phan lin tho g khi doi v6i CO2 k o g d i d n6ng dQI, 1 \:, ~.MAC huy b hOEmtoan phan u g v6i s1,1giam oxy trong khi thd h ~ w

trong khi do phan ling l?i v6i CO2 nhanh len r6 r~t

Phan X?kieh thieh h6 hap eua CO2 giam d~n khi tang dQ sau gay mf81,1eo m?eh ph6i phan ung l?i doi v6i s1,1thieu oxy trong khi thb 1f.;jjkho g bi suy yeu dmue dQ thap khi gay me b&n halothan

2.3 H ¢ th6'ng tim m? ch :

Halothan gay giam h yet ap b.long duong v6i dQ sau'eua me va ,w

hUd g lie ehe eo tron eua m?eh mau ng ?i vi Hon nua con anh huCa~lie ehe tae d\mg gay co m?eh ngo?i vi eua norepinephrin nQi sirli

N6ng dQ,eatecholamin huyet tu n tang len khi khdi me ,( IIhalothan.' ,'

~fh?nan tOEmc6 the Wi lieu 10ml dung dich 1/100).00Q, epinephrin trong vong

~~oo10 phut D§ cho g lq_isv 10q_nnh!p that do clung epinephrin c6 th§ dung

~l£docain 0,5-1% viii lieu 0;5-1 mg/kg tiem tlnh mach cham

~: c6Ul C dVng cQn d n v i thuoc gian co(myorelaxant)

W C6 tac dQn rat it len chuc nang thrin kinh co (neuro-mu8cular), nhlin

halothan phong te heat dQn cua n repinephrin 1 n co tim Halothan

ngan can su heat hoa cua adenylate cyclase b i catecholamin lam

giarn hieu l ire co co,th§ tich tam thu va hieu suat tim

Cac than kinh ph6 giao cam cua tim bi nhay cam gay ra nhip cham.Chii y rieu gay me k60 ga i han 5 gid hcac han nira thi S l J su ye u cua

co tim se kh6n thay nira khi lam me sa u hen: nhjp tim tan , hieusuat cua tim va th6 tich tam thu trd lai hoac cao han binh thucn

Roi loan nhip that thucn lien quan tdi 81,1'thieu oxy khf thd VaG va

uu than Nut xoan bi uc che AV nhip nut thuo g thay (co che' con

chua ro) c6 nguoi ch r§_n halothan lam co tim nhay cam voi

epinerphrin gay ra tang tv dQng d ch6 dieu nhip that, sau nay c6nghien cuu lq.i cho r~n tv dQng that bi ch~n lq.i khi gay me vai

halothan

449

- Ap l uc 6ng m a t c h ung c6 t h ~ giam , va l a m gia rn ca su tang ap hflll~

mat chung doS v dap ling voi fentan l

2 6 Th ;J n

Halothan lam giarn dong mau than, giam muc loc cau than, giaUlij

t et natri nieu va th6 tich nuoc ti6u, c6 anh hU(Jng thu phat rJ , gt

than rib u su kich thich giao earn, hu et dong n6i chung va cac y ~ i r;

hormon n o a i than

Khi gay me ban holothan su tv dong dieu chinh dong mau q a ]; ,

duoc duy tri cho tdi gidi han tv dQng dieu chinh d mire thap he) , r.,

ap luc c6 th6 dat duoc

.Kh6ng thay n6i den halothan doc voi than nhu la methoxyfluress:

enfluran: Vi khi d ng halothan luong ion flo tv do giai ph6n rs 1:

khoang 20 umol/I rna nguring' dQcvci than la [F tv do] 240 urnob],Nhfrng ngudi da dfll1gINH (isoniazit) kh6ng gay me dtiC}Cb~n ! h , llI

halo than vi INH kich thich sv giang hoa lam tan ion F c6 tb:"~

' ;f[;i

Halothan de dang qua han rao rau thai va lam su h hap thai n ii

Lam gian cd tv cung, CLidng dQ tUdn ling voi lieu lU<;ing,n , !II

dung t6t cho ngo9oixoay thai va lam giam nh€?can co cua til cung ,

Lam giam sv dap ling cua tv cung voi d§.n x at eua nam c~.~(ergotamin, ergoto in, oxytocin ) cho nen de chay m E W tU:cun~ SII

de, vi v$.y dn chu y khi m61ay thai (c~esarean) va sau de ";

MQt so' s?mph~m chuy€n hoa cua halothan c6 n u6n g6c phan ttLemI

la dQcto'1090gai n Halothan dU<;icchuY6n hoa binh thud g theo d d

hoa CytP4 0 tu truoc b~ng phenobacbital c rbuahydro da ~

(benzopyren, methylcholantren) ho~c trong dieu ki~n thieu oxyrs~

:~';~

; ,

450

&-.:.

~ ;,(

r

~ ' 0 n u i halo than luon tao nen nhirng t6n thuong nho sieu cau true

~ i cua te bao gan, lam tan transaminase, la hien tuong ph6 bien do

! ~ , ngQ clQC.N gu c lai viern gan lam san cua halo than c6 day clUtinh

~ cua hien tuo g tan nhay cam C6 th6 chat chuyen hoa cua halothan

~~' gelnvao thanh p an cua man te bao tao ra d nhieu nguoi phan ling

r mien dich clQCvoi tebao cldchong lai rihfrn gthanh phan man bi huy

C

~~ Hfru het halothan thai ng yen ven q a duong phci, sau 10 ngay con

t ~h~::~ t~~~ (c6 tac gia 12%) halothan duoc hap thu vao co th~ va

!:

~ trai qua thoai bien sinh hoc d gan chu yeu qua cluo g oxy hoa, nhung

;' neu thieu oxy mau c6th6 bi khv

" DU'Qcoxy hoa nhd (Cytochrome) P'i"O chat chuy§n hoa sau cung la acid

trifluoracetic va ion brom, flo

Cac san ph.im chuy6n hoa clUQCthai ra theo mioc ti6u la ion brom t1;i

do, ion flo va acid trifluoroacetic

Halothan dung voi isoniazit (INH) lam INH de dan bi giang hoa t q_ o

ra chat chuy6n hoa clQCvoi gan

Tuy thea nguoi benh:

+ Voi tre em co th5 khdi me b&ng Mask

+ Suy h6 hap: viern p e' q an dang hen

+ Nhuoc co:trarih sV dung gian co

+ Benh huyet sac to

Theo loai phau thuat:

+ M6 cap cuu+ M6 mat

+ Tai miii hong - rang ham mat: (n uoi ta dang nghien cuu hi !

huyet ap d giarn chay mau)+ B6~ung cu g gay me tinh mach

IV CHONG CHI DINH

Khi dung halothan bat buoc phai Slr dung h~ thong gay me b~j

C6 th~ Slr dung he thong hd, nua kin, kin

Dung he thong vong kin het it thuoc han 10 l~n vong h6, kh6ng ~ t~nhi6m m6i trud g, kh6ng h<;licho nh6.n vi6 y teo Khi luu luqng IKIJi

th~p cling dung dUQc.Khi dung h~ th5ng nay b~t bu~c pha.i theu dO

di~n tim, Fi02, CO2, Sa02, EtC02 va phai co h~ thong hut khi thSi ' J1I

neu dung vong h6 c~n c6 bi~n phap de phong cho nhan vien yteo"~

452

Theo doi lien tuc mach, huyet ap, dieri tim.

+ NeD.thay ha h uyet ap can giarn nong d9 halothan

dan voi toc d9 ch am hen, kidm tra lai viec cung c p oxy, tinh

c n kiern tra them tinh tran kali mau ngoai ca viec da lam 2J

g<ln day cho thay nhieu tr uo g h p ca th ng so oxy, CO2, huyetd9ng 6n dirih rna co rigoai tam thu that co th~ dung dung dich

cung eho ket qua tot

M9t so truo g h p sau k i da lam ca buoc tren rna khong co ket

Halothan lie chc cd tim va ho hap khi gay me phai het sue ehu y de

Th eo d oi li e n t uc m a ch, hu y et ap , dien tim

+ Neu thay ha huyet ap din giam no g d¢ha10than.+ Ncu thay roi 100n nhip tim can ngirng' halothan sau d6 1 i ,2-

dan voi toc d¢ cham han, ki6m tra lai viec cung c p oxy, ti

tran uu than Mot so truong hop khi dung c6 ngoai tam thu tl:

din kiern tra them tinh tr arig kali mau ng ai cac viec ds Ian

tren Thee kinh nghiern sli dung d benh vieri Viet Due thci g1g§.n day cho thay nhieu truorig hop cac thong so oxy, CO 2 , nu;

dorig 5n dinh rna c6 n oai tam thu that c6 th6 dung d n di

KCL nho giot tinh ma h cho thay c6 ket qua rfi ret

M¢t so truong hop sau khi da lam cac buoc tren rna khong c6 ket q

din ngirng halothan

Chu y halothan la thuoc ma khong c6tac dt;mg giam dau cho nen ~

m5 phai cho th oc giam dau

Halothan c¢ng d6ng t:lc dVng voi thuoc gian cd nen khi dung gian

d.n chu y d~ sli dvng lieu lu<;Jngcho thich h<;Jp

Sau khi gay me b&ng halothan keo dai thu(jng c6 ret run, c6 th~ bt

non, non khi d6 cEinthiet u am cho b~nh nhan, eho thd o y, c6 tH§~

them m¢t it thuoc an th§.n (Seduxen, Dolargan)

Halothan la m9t thuoc me mf;l.n ,d§ th1;tchi~n, me nhanh, dnh nhm

HalothRn {tr. r.he Co tim va ho ha'p khi gay me phai het suc ch y

phang cac bien chung nay nha't la khi khdi me va khi m6 chay a

Halothan khong c6 tac dvng giam dau nen khi m6 phai ch h

~•di fluorornethyl ether (CHF2 -O-CF2 CHFCl), c6 cau true hoa hoc nhu sau:

Enfluran c6 hi~u h,tc gay me m~nh, hoa tan trong mall ',2 mo t1.1'angd6i

me nhanh Nang dQ(J ph§' nang gAn nb1.1'nang dOhit VaGcho phep ki@m

tra, dieu khi6n muc dOm e linh ho~t N8ng dQt6i thi6u thu6c me- 0 trong

nita oxyd la 1,2 % Rhi n6ng dQIOn han 4,25% co th6 gay chay trong

2 % oxy va nita oxyd Enfluran c6 chi' sO'gay me thap han cac thu6c

methoxyfluran, halothan ho$.c isofluran d tren chuQt (chi sf; gAy rnA=

n6ng dQgay ngling th~ ngling tim/n8ng dQgay me)

~ IL TfNH CHAT D119C LY

(

\ '

hinw - CBF) va ap h,tc nQiS 9 (Intra cranial pros sure - rcP).8\t tang thong khf

~ -silam d EW ng1.1'c;ictac dVngnay, tuy nhi8n enfluran lam tang dong mau

-I~ '

455

n ao i hen h al ot h a n E n £1 u r a n l a m g i a rn mu c chu y e n h oa cu a n ao va c6 Wl i

g l u c o s e va du tr u g l y c o ge n

K hi ga y m e bang enfluran s u k i c h t hi c h n ao s e t a n 'I' r e n d i e n na t) · iIl

co, co th 6 t h ay giat rung , co c u g c o mat va c o c h i S 1jkich thich s e giarn ;

giarn no ng d Q enfl u r a n v a uu th a n ( h p erc a p i a ) , t r a i l a i s u ki ch th i cli J

t ang k i n o g d e_)cnfl ur an va n iro c tha n ( h poc a p ni a)

ho a c u a n a o c h i 6 m ir e ti e n gay m e Khon g c6 d a u hi e u t6n t hucn g thieu " : ' : ket h o vo i enflur a n g ay r a h eat dong c o g i a t

ban c han khi dun g d n t hu c:ln e n£1ur a n d d ~ t nQ i k hi qu a n H a lo tha ~ ' <

kh6ng co n g y h i§ m do kich t h f ch hQ t ho n t h§.n k inh t un g lidng Enfl ill B

c o ga y ro i 1 0 (;l Ild i QIl nao d6 v i cac b i § u h i~ n s6 ng nhanh , b i e n dQ cao WI

m Q t h o ?t dQ n g dQ n kinh Vi v~y k h ng dun g en£1uran gay me cho n h ~

E n £1u ran l a m s u y ye u h o h a p , nhieu h n 6 cung mQt muc MAC s.o ~

h alo th a n v a i s o£1ur a n , n e u t h e m nito o xy d se doi kh a ng l <;l i tac d , " ,

En £1 ur an l a m g iam ht<;J ng c h a t nh ay tron g c ay phe quan , l a m g:;Jili

ph e qu a n g i o g h a lo t h an T h t ich khi 1 11u t h ng gi a m t ong khi ~

toc d Q h h a p khon g d i h o~ c t a n nh f? Ph a n un g thon g khi doi \'i i~

kh6n g gay ho va co th& t th a nh qu a n ;~

','!!1

En£1ur a n l am suy 'l eu c o tim , l am g i a m 111u111 g g tim va g i a m hu y€: ·" i

thu va nhip t m t a n , tron g khi d 6 suc ca n to a n ph § n n o<;li vi va a p h iC ''' :

d c) n mQ.ch gi £ un , n e u dung vei h a i MA C e n£1u1' a n c6 t h§ lam giam ' hu y e ij

tl'{lm t1'9n g Sl} kich t hich tu £ in h oa n n ay la do k i c h thich giao c a m b aa:~1

t a n g' PaC0 2 C o y ki e n cho r:in g d 9 g m i;lc h vanh co th~ gian

ban d § u l ? i d ao n 1 t<;Jc l<;li , t h $, m ch i c 6 t h ~ thay r6 s 1j U' m g l en tr e n gi aJntt

k i6 m chun g, di e u d6 c6 t h la h i ~ u qu a k i c h t h ic h ~ - a dren er gi c khi ga j , flJj

! ~ Enfluran lam cotm nhay cam voi catecholamin noi sinh va rig ai sinh,

t ' • ' n ung su roi lo a n nhip tim khi gay me bang enfluran ithen so voi halothan

"'" Enfluran gay ra mo t ire che tuorig doi su giai ph6 g catecholamin tv nhien

~~.;:; enfluran

~ glycasid tro tim S8 giarn Cac thujic uc che' lam tan kha nang uc che su co

~~.5 i co tim, vi v~y ca'm dung enfluran d nguoi dung thuoc uc che 0.

f " e c

~ Enfluran gay gian cd do lam suy y u h$ th6ng th§.n kin trung udng va

~: thll teu

I

r :

Icd eua ve uronium Vi v~y khi dung eae thuee nay phei hc)p voi enfluran d~

457

' ,

?

8 Chuyen hoa sinh h9C

, o J

t ,

j

458

~"ther voi cau true hoa hoc nhu sau:

'" La mot chat long 1.,(h6ngmau, 6'n dinh d nhiet dQ phorig va kh6ng can

i dl a t bao fI118n , khon gfiy chay trong 1,hfmg khf, nio oxyd va oxy Trong

! " rutdoxyd Kh6ng phan ling voi kim 10l?-itrong h~ thong, co mui cay n11.((

~

~.

~ phep ki6m soat dQ sau clla me de hdn

t~~

f " (EEG) chi ra gio g nhu dUdng m~u, nhu ciiu oxy eho chuy§n hoa clla

ho ac thicu oxy Nh ung n kh ong c6 tac dun g' phorig ngua v oi s u OO l €

khorig tang len Su dieu chinh tu dQn dong rnau nao duoc duy tri va ap }~

nQi S9khorig tan ngay ca khi th~ tich rnau riao tang Dieu nay c6 th~ doti

q a cua su giarn th§ tich nuoc nao tuy Day la di5m l<;licua isofluran so •~i

halothan vi khigay me ban ha l ot h a n gay r a tang dong m a u n ao, tang ' J±

tch mau nao, tang ap luc noi so, mat khac su dieu chinh tv dQn duy u

kh o ri g tot, nhu diu oxy cho chuyen hoa cua nao giarn i hon, toe dQ san xwl

nuoc nao tuy tan sv can trd tai hap thu nuoc nao tuy tang Can "iiI

enflu1'an thi dong mau nao tang, ap IlfCn i S9 tang, san xuat nuoc nao Ut ,

tang, s1,ican trd vi¢c tai hap th nuoc nao tuy tan , tren di~n nao do c6b \~

hi¢n cdn dQn kinh s6ng nhc.m dQt ngQt Vi v$.yisofluran c6 gi6i h0n an t~8]cao.hdn enfluran, halothan v J.methoxyfluran

2 H$ thong he hap:

Isoflu1'an lam giam Slfh6 hap r6 r~t, giam th§ tich kh11uu thong va t~J

toc dQ ho hap, phan ling thong khi doi voi carbonic b~ suy yeu ngan " j

enfluran va halothan Neu tang dQ sau clla me khi dung isofluran thi tllWtich k i hiu thong S8giam ma kh6ng c6 sv tang bu ve toc dQ ho hap n u j lj

clung halothan 8lf kich thich ph§.u thu$_t S8 lam mat tac dVng clla Slfgi.s

ho hap hie d§.u Phan ling thong khi voi sv thieu oxy khi dung isofluran , m

h n khi dung enfluran Isofluru c6 mui cay nhC?nen bat l<;likhi kh i ~

b~ng mask cho tre em Khi me nong hoac khi tho at me c6 th§ c6 nac ,,~

isof1uran lam gian phe quan tot hdn .\

nh~p tim do Svd y tri cvc bQ phan X0 ap Ivc dQn m0ch clmh (car~

baroreflexes) 8V5 dj,nh tu§.n hOEmdU<;Icdu tri ngay ca khi me s ij

8v giam ap Ivc dQng m0ch h~ thong can ban nhu la mQt ket qua ~

8lfgi1:tlll ::; U C Call h~ thong m0ch va sv gian m0ch ng00i bien Isofl ,'.~

duy tri sl;f 6n djnh cua nh~p tim d cac b~nh nhan da dlI~

c teeholamin, lieu h <;lngepinephrin (adrenaline) d§ gay ra n oSJ,it ' ''; :

thu phai 3 l§.n hdn khi gay me voi halothan .~

Khi phoi hdp nitd oxyd voi isofluran d gay me c6 th§ gay ra mQt so m';~

dQkich thich a - adrenergic Ngudi ta da chung mi~h r~ng isofluran uc ~~

Isof1uran lam gian mSJ,chvanh m~c du hi~u lvc khong b~ng nitroglyce,'

ho~c adenosin Sl,t gian cac dQng m9-ch vanh binh thuCing ve m~t ly th yeth§ la111tr~ch huang dong mau khoi cac t6n thudng hC?Pco djn , day gQ' "

~IE;,1 ~

~ trong hoi nhip tim nhanh, hoac l am giarn ap luc tuci mau Mac du c 6 nhung

I , k it qua am tinh nhung nhieu nha gay me tranh d ng i sofl u ran d cac benh

i nha n c6 berih dong mach ' vanh.

~ : cua cac glycOS~9 tr o tim se giarn, cac thuoc ire che 0 l am tang kh a

~ nang ire che sci cd tim v u a phai so vo i h a l ot h a n va enfl ur a n.

l ~, 4 H~cd

( I sofluran l am gian co xuong, n6 lam tang k a nang cua gian co k orig

~ : hv cue va g i a n cd khv cue, tac dV ng n ay tu'dng t 1j e nflu ra n nhu'n g m <;3 nh

i f bon h a l ot h a n 2 - 3 l ~n Vi~c c h o t h ?e m cafe in voi i soflura n gay r a s 1j co cd it

~ b ~ so vo~ ha_ l o~ha n va ~?fl u :a ~ ; dli ~u 1u' ~ n g gay ra g i an cd t h u $, n ti $ c h

t I sofl u r;a n gay g i an cd tv c u ng d li e u l u'<;Jngtu'dng u ng. <) li e u t h a p no l a m

i ; ~1.Jd ap ung ella c~ tv, c~~g voi d ~ n x at nam c 1j a ga (nh u' erg ot a min ,

~ G e : rgo t oxll1,ergome t ll1 va Vei l oxy t OC ll1 ).

t o: D ong ma u toa n b9 clla gan giam khi gay me b<1ng iso flu ran S 1j cun g ca p

~ f (? i:\? 1c h o gan c6 t h ~ ~u'c;J,c~ u ;rlt ~them ~o i i s~fl u r~ n so vo i h ?a l ot h a ~ n e n ~oi

~ - mau gan du'c;Jcd u y t n VI V<;3.y c ac th u' n g l9m ch u c na n g ga n b ~ a nh h l.t dng rat I t.

r, · 8 .Chuyen hoa:

~ : I ~oflura n d u' QC tha i h~u he t q a p h i - 99,5%, chi k h oa n 0,3 d e n 0, 5%

f: (h y~n hoa d ga n , sa n ph §'m cuoi c u ng l a ac id tri flu o r oacet i c v~ i on flo vo cd

t T -) tha i q a n u' oc ti~ u Voi na n g dQ gay me th i l Uc;J n g flo k h 6ng dll gay dQ C

t If{'Jit h $,n, c6 tac g i a c h ng minh l a voi 20 MAC gid isofl ur a n m o i l a m c ho mu c

t oc m flo Vl.t<;Jt 5 ~ t mo l ll i t.C li ng do c hu y~n h oa rat i n e n s 1,1n g y hiS m d oi vo i

r~[1 d tn h va k h n c6y k i e n nao ve s 1,1 d9C c ll a i sofl u ran v oi ga n va t h $, n.

~

Sevofluran (co to ten la ultane) co ccng thuc (CF3)z CH-O-C

thuoc me ho Halogen, cau true h a hoc nhu sau:

Sevofluran khorig co mui hang, trong lucng phan tv: 200, di

58,6 ° C , ap luc hoi bao hoa tai 20°C la 162 mmHg.· D9 tan

mau cua sevofluran 16n han desfluran mot chut (A mau/klif (voi 0,42) nhung hieu luc gay me lai kern enfluran N6ng (

nang toi thi§u: MAC: 2,0%

han nen sevofluran la thuoc duoc chon nhieu nhat d§ k11di

hap, mat khac voi nhiet d9 sci 58,6 ° C va ap lue hoi vua h

sevofluran cho phep -co th~ dung birih bee hoi thong thudngi

So voi cac thuoc halothan, sevofluran la thuoc it 6n din tro

sedalime, m9t so lUc;Jng16n sevofluran bi giang h6a tro g v:6inhi~t d9 cao va trCilngthai kho (d22 ° C , 6,5% bi giang h6a, ti5

giang b6a t6i 57,4%) M<)tphgtn nha sevofluran bi gian li6a

co th6, d trong moi tru n 168m cao sevofluran bi gi€mg 116a

han (trong bary lim,3)

1 H~ thong th a n kinh trung ltdng

Do d9 hoa tan trong mau thap, nen dung sevofluran k di me I

thay d6i d9 me va thoat me cilng nhanh

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