Lieu dung
Khdi me dung 2- 3mL dung dich 2,5%, sau do co th~ tiem tiep.
Lieu toi da Ig/ Ian gay me.
3.3. Ketamin
Tac dung va co che'
Ketamin la thuoc gay me tinh mach co thoi gian tac dung ngan. Day la
thuoc gay me phan liet, co tac dung giam dau va uc che' tam than,
Co che: chu yeu uc che acid glutamic la chat d~n truyen kich thich.
Thuoc gay kich thich ho hap, lam gian co tron phe quan nen dung duoc cho nguoi bi hen phe'quan.
Thuoc gay kich thich tim, lam tang nhip tim, tang hru luong tim, tang
huyet ap do kich thich than kinh giao cam. Ketamin cling lam tang hru luong
mau nao, do do cling gay tang ap luc so nao.
Tren lam sang, ketamin thuong dung phdi hop vdi cac thuoc gay me va thuoc gian cd.
Chi djnh
Do co nhieu tac dl,lng khong mong muon ve tam th:1n nen it dung cho gay me thong thudng. Thuoc chu yeu dung gay me cho cac trudng h<;1pdl}.cbi~tnhu ngudi bi hen, trl,ly tim m:,tch, trl,ly ho hap.
Ngoai ra, ketamin cung du<;1Cdung d~ giam dau trong cac thu thu~t c:1t bo mo ho:,tita, bang bo vet thudng, vet bong ...
Tcicd1;fngkh{mg mong muon
Thudng gl}.pla cac roi lo:,tn ve tam th:1n nhu mat dinh huang, ao giac, ac mQng, tang ap h;tc s<?nao, kich thich tim, tang huyet ap.
Ngoai ra, thu6c eon gay buc3nnon, non, run, ehay nuac miit, nuae mlii ...
Chong chi djnh
- Tang huyet ap. - Tang nhan ap. - Tang ap h;tc s<?nao. - Roi lo:,tn tam th:1n.
Lieu dung
- Tien me: 3mg/ kg tiem blip.
- Khdi me: 0,5- 2mg/ kg tiem tinh mach (4- 6mg/ kg tiem blip). - Duy tri me: 0,5- 1mg/ kg, tiem tinh mach,
- Giam dau, an than: 0,2- 0,8mg/ kg tiern tinh mach (2- 4mg/ kg tiem blip). 3.4. Propofol
ra« dlfng
Propofol (2,6- diisopropyl phenol) co tac dung an than gay ngu, la thuoc gay me tinh mach quan trong hien nay.
Hoat tinh gay me nhanh, manh hon thiopental nhung tinh nhanh hon va it met moi sau khi tinh, Thuoc it d9Cvdi gan va than, khong gay budn non va non.
Propofol thuong duoc dung lam chat cam ung me nhanh sau do phffi hop vdi cac thuoc gay me ho hap khac d~ duy tri me trong cac phau thuat keo dai hoac dung don d9Ctrong cac phau thuat ngan.
Ttic dung khongmong muon
- Thuoc gay suy ho hap, giam huyetap do giam sue can ngoai vi.
- Than trong vdi nhfing benh nhan co that mach vanh, nhat la khi phdi hop vdi nitrogen oxyd hoac thuoc ngu.
Chongchi dinh
- Dung trong san khoa. - Tre em dudi 3 tu5i.
Lieu dung
Khdi me 1,5- 3mg/ kg tiem tinh m~ch. Duy tri me: 3- 12mg/ kg/ gid.
3.5. Etomidat
Etomidat la thuoc ngli khong barbiturat, khong co tac d\mg giam dau, thdi gian tac d\lng rat nglin. Sau khi tiem tinh m~ch 0,3mg/ kg th~ trQng, tac d\lng gay me duy tri duqc khoang 5 phlit. Vi tac d\lng nglin nen chu yeu dung khdi me, sau do phoi hqp vdi thuoc gay me ho hap d~ duy tri me.
Uu di~m: 5n dinh ho hap, tim m~ch, duy tri duqc luu luqng tim va ap suat tam trudng nen dung duqc cho b~nh nhan bi suy giam chuc nang cung cap mau va oxy cho cd tim.
Ttic dung khong mong muon
Thuong g:Itpla kich ling noi tiem va lam giam dap ling cua vo thuong than vdi stress, gay may co.
Che'ph6m va lieu dung
Etomidat (j1midat), dung dich 2mg/ mL trong dung dich propylen glycol35%. Tiem tinh mach O,3mg/kg.
3.6. Cac thudc gay me tinh mach khac
Cac thuoc an than gay ngu (d§.n xuat cua acid barbituric va
benzodiazepin) khi dung lieu cao deu gay me, tuy nhien chi c6 mot sO'thuoc duoc dung lam thuoc gay me tinh mach la thiopental, hexobarbital, diazepam, lorazepam, midazolam ...
THUOCGAVTE
1.D~ Cu'dNG
1.1. Dinh nghia
Thuoe gay te la thuoc co kha nang ue che' co h6i phuc su phat sinh va d~n truyen xung d9ng than kinh tu ngoai vi vg trung uong, lam mat cam giac (cam giac dau, nong, lanh ...) cua m9t vung co th~ noi dua thuoc. Lieu eao, thuoc ue eheca chuc nang van d9ng.
1.2. HB:pthu cua thudc gay te
ThuOcgay te thuong duoc dung bang each tiem hoac boi true tiep vao noi can phong be than kinh. Qua trinh xam nhap thuoc gay te vao te bao than kinh d~ tao tac dung thuong phai trai qua 4 giai doan sau:
- Khueeh tan vao rnd: rmrc d9 va toe d9 khuech tan phu thuoc vao tinh chat ly hoa cua tung thuoc.
- Thuy phan trong dich gian bao: trong lam sang, thudc gay te thuong dung dudi dang mudi d~ tan, d~ng nay khong qua mang te bao ngay du<;Je.Dudi anh hudng eua moi trudng kigm nh~ trong dteh gian bao, thuoe gay te thuy phan t~o ra d~ng base tlj do, tan du<;Jetrong lipid, d~ dang qua du<;Je mang tebao.
- Xam nh~p vao te bao thftn kinh: d~ng base d~ tan trong lipid nen d~ dang qua dU<;Jemang vao te bao thftn kinh.
- Phat huy tae d\lng: khi xam nh~p vao te bao thftn kinh, do co tinh phan elje nen thuoe gay te se g&nvao thanh phlln tudng ung eua te bao thlln kinh lam 6n dinh mang nen co tae d\lng giam dau.
1.3. Tile dung va cdehe"
- a lieu thap thuoc gay te chi co hie dung giam dau, khong lam mat cac cam giac khac,
- a lieu dieu tri va lieu eao: ngoai tac dung giam dau, thu6e gay te con lam mat cac cam giac khac (cam giac nong, lanh, dung cham ...), ue ehe"d~n truyen van dQngva co cac tac dung khac (tac dung tren tim mach ...). Tuy nhien, tac dung ella thu6e gay te v~n uu tien tren day than kinh cam giac hon vi kieh thuoc soi cam giac nho va it myelin hen (cac day than kinh co dQ nhay cam vdi thuoc gay te khac nhau: soi nho nhay cam hon sci Ion, sci it myelin nhay cam hon sci nhieu myelin).
- Co che: thu6e gay te lam giarn tinh tham ella mang te bao vdi ion Na" do giin vao mat trong ella mang te bao, ngan can s\i khi't e\ie mang te hao (an dinh mang) nen ngan can d~n truyen xung dQng thAn kinh vi v~y co tae d\lng gay te (hinh 3.1). Ngoaimang OrrN Mang Sinh thllang~,"g=:=;=~=i==T=hU=6~ciltl-e__ ..., Tin hl9u thin klnh Trongmang I K6nh natri OrrN -90 rrN [j KlInhkall -90 rrN
Hinh 3.1. SI,(dan truyen xung d(>ngthan kinh ddieu ki~n blnh thLfong va khi co thuoc gay te
1.4. Cae each gay te
- Gay te he m~t: la gay te phong he ng(;msQithAn kinh hflng each hoi ho~e tham thu6e len he m~t da ho~e niem m:;te.Phudng phap nay thudng dung khi viem mi~ng, viem hc;mg,ehu~n hi nQisoi hay d~t nQikhi quan ...