SU BIEN OOI NGUNG TAP TIEU CAU VA FIBRINOGEN MAU VOI ROI LOAN LIPID, TANG HUYET AP 6 BENH NHAN
DOT QUY THIEU MAU NAO
I. OAT VAN OE
Tai bien mach mau nao (TBMMN) la mot the roi loan tuan hoan nao cap, thucmg la nang, xuat hien dot ngot, neu khong gay tu vong thi cung de lai nhQ'ng di chirng rat nang ne. Theo thong ke cua TCYTTG nam 1998, o cac nuoc phat trien TBMMN la nguyen nhan tu vong dung hang thu 3 sau ung thu va benh tim mach. Ty le mac benh o cac nuoc phat trien rat cao. Theo Manzella SM, Galante K (2000). o My moi nam co d6n 700.000 nguoi mac benh trong do ty le tir vong chiem 1/ 3 trucmg hop.
Nghien cuu huyet khoi dong mach cho thay su tang dong lien quan chat che voi roi loan lipid mau va tang huyet ap. Thuc nghiem cGng nhu tren lam sang deu xac nhan tac hep dong mach do huyit khdi la mot bien chung thuong gap va gay hau qua nang nk 6 benh nhan tang huyet ap. Nhu vay mac du ap lire mau tang cao, bien dong va keo dai nhung bien chimg chinh a nhiing benh nhan nay lai do huyet khoi gay nen chu khong phai do chay mau. Nhieu cong trinh nghien cuu da cho thay mot tinh trang tang hoat hoa he thong dong cam mau dan din huy6t khoi gay tac hep dong mach a benh nhan tang huyit ap. 0 benh nhan tang huyet ap co dly dii cac yeu to ga\- huyet kh6i trong thu nghiem ciia
Biii Manh Hiing*, Doan Dure Hoang', Huynh Van Minh**, Nguyen Phu Khang"*
Virchow: Bat thuong thanh mach, bk thucmg dong chay ciia mau, bat thuong cac thanh phan mau. '"--•. '' - -t
Tren the gioi co nhieu cong trinh nghien cuu ve dot quy thieu mau nao chung toi nhan thay chuc nang cua tieu cau c6 vai tro rk quan trgng hinh thanh mang vira xo dong mach va qua trinh dong mau voi yeu to huyit ap,r6i loan lipid mau 6 benh nhan dot quy thieu mau nao,trong chuyen de chung toi xin dugc de cap den:
1. Su bien doi ngung tap tieu cdu va fibrinogen trong dot quy thieu mdu ndo
2. Moi tuang quan giiia do ngung tap tieu cdu, yeu to dong mdu vdi rdi logn lipid, tdng huyet dp trong dot quy. thieu mdu ndo
I I . BIEN OOI GIU'A NGU'NG TAP TIEU CAU VA FIBRINOGEN MAU VOI ROI LOAN LIPID 6 BENH NHAN TANG HUYET AP DOT QUY THIEU MAU NAO
2.L Ngu-ng tap tieu cau
Ngumg tap tieu cau la mgt xet nghiem co gia tri trong danh gia chuc nang tieu cau.
Danh gia do ngung tap tieu cau la mgt trong nhijng phuong phap ngay nay dugc sir dung rgng rai nhat de nghien cuu chuc nang tieu cau, dac biet la trong nhimg truong hgp tang
* Kcnii vien irung uang Hui;
**Trudiig Dgi hoc )'Duac Hue
***HQcvienOuanv 103
hoat hoa tieu cau dl gop phln quylt dinh dieu tri thuoc uc chi ngung tap tilu cau.
Ajzenberg, Dougad M., Lechi C. diu xac nhan tang ngung tap tilu cki dong vai tro chinh trong cac benh ly benh dgng mach vanh cap tinh, nhoi mau co tim, dau that nguc khong on dinh o benh nhan THA.
Mat khac, Puri R.N. xac dinh ADP la chat gay ngung tap tieu cau dau tien va quan trgng nhat. ADP khong chi gay ngung tap tien phat ma con gay ngung tap thu phat.
Ngoai ra, ADP con gay thay hinh, doi dang va bai tiet ciia tieu cau. Chinh vi vay, trong cac nghien cuu danh gia tang hoat tinh tieu clu, ADP luon dugc sii dung de lam chat kich tap va tang ngung tap tieu cau voi ADP phan anh mgt tinh trang tang hoat hoa tieu cau.
Breddin, qua nghien cuu ciia minh, cho ring tang ngung tap tieu cau la mgt yeu to nguy CO tac dgng mach va xet nghiem danh gia ngung tap tieu cau da dugc chi dinh rgng rai cho cac benh nhan bj viJa xo dgng mach do tang huyet ap, roi loan lipod mau.
Grotemeyer nghien cuu ngimg tap tieu cau o 33 b?nh nhan nhoi mau nao va so sanh voi 71 nguoi binh thucmg, ket qua cho thay co 46%
b?nh nhan nhoi mau nao do ngung tap tieu cau vugt qua X + 2SD nhom chiing.
Sharp DS. nghien ciiu ngung tap tieu cau a benh nhan bi benh mach vanh da khang dinh sir hoat hoa tieu cau co moi lien quan chSt che voi benh dot quy thieu mau nao.
Nhu vay, ket qua cua hau het cac nghien ciiu deu xac nhan vai tro quan trgng cua tang hoat hoa tieu cau trong huyet khoi dong mach cQng nhu gia tri cua xet nghiem^ do ngung tap tieu cau trong danh gia tinh trang nay.
Truoe day, o Viet Nam, danh gia ngung tap tilu clu chi dua vao do tap trung tren lam kinh va dugc sir dung nhu mgt xet nghiem mang tinh chit dinh tinh, gop phan danh gia
trong nhiing trucmg hgp nghi ngof giam chiic nang tieu cau. Tu nam 2006, Benh vien TLT Hue dugc trang bi may do ngung tap tieu cau tu dgng va chiing toi bat dau triln khai nghien ciiu ngung tap tieu cau a nguoi Viet Nam trucmg thanh binh thuong, tilp do la cac nghien ciiu ngung tap tieu cau trong mgt so tinh trang benh ly. Hien nay, may do ngung tap tieu cau da dugc trang bi a mgt s6 benh vien va ky thuat do ngung tap tieu cau dugc ap dung kha rgng rai trong thuc tien lam sang voi uu diem de dang nhan thay la danh gia mgt each chinh xac kha nang ngung tap cua tieu cau trong tat ca cac trudng hgp roi loan:
giam hoac tang ngung tap.
2.2.Vai tro cua fibrinogen trong qua trinh dong mau
Fibrinogen dugc tong hgp boi cac te bao nhu mo gan, xap xi 75% fibrinogen co trong huyet tuong, noi ma nong do cua no thuang dao dgng tir 160-450 mg/dl. No co the co mgt lugng it hem o hach bach huyet va co the di vao tuan hoan qua cac bach huyet gan. No CO the dugc tim thay trong nhieu mo bod cac ky thuat huynh quang. Cac nghien ciiu su bien doi fibrinogen dugc danh dau bang dong vi phong xa cho thay rang dgng lire hgc ciia di hoa fibrinogen la phiic tap. Ti le luan chuyen ciia fibrinogen nguoi tu 1,7- 5,0g/ngay (30-60mg/kg/ngay). Dofi song nua doi sinh hgc cua fibrinogen tu 3-5 ngay. Cac nghien ciiu su bien doi fibrinogen dugc danh dau lode cho cac con so tuong tu.
Co bang chiing cho rang di hoa xay ra lien tuc va c6 the xay ra lien quan den su chuyen doi fibrinogen thanh cac dan chat hoa tan CO trgng lugng phan tu thap hon. Cac dan xuat nay thong thucmg chiem 20% fibrinogen huyet tuong, dieu nay co the la ket qua hoat dgng cua plasmin. Su di hoa fibrinogen dugc thiic day boi nhieu yeu to sinh ly, trong so
chiing boat dgng manh co the dan den su tinh ha)- cap tinli cua no deu dan den sir gia thoai giang dang ke cua chuoi alpha. Trong tang do quanh cua mau \ a su ngung tap hong qua trinh na\- co thi giai thich mgt lugng nho cau.
tlbrinopeptide .A. thuong co trong mau. 0 co 2.3. Vai tro ciia fibrinogen voi su tien thi nguoi. cac \i tri di hoa cua fibrinogen trien ciia benh mach mau va trong dot quj;
chua dugc biet nhu sir thoai giang co the nao thiic hien dugc bai cac le bao ngi mo. \ a
duong nhu .\a\ ra a toe do nhanh hon a cac
\'i tri ngoai bao.
Tang fibrinogen mau do cac tac nhan
Fibrinogen la mgt \'eu to quan trong trong he thong dong mau. Fibrinogen dugc thua nhan la YTNC doc lap cua cac benh mach mau. Sir tien trien ciia benh xo vua
Theo
sinh mu \a cac chiet xuat khac ciia vi khuan dgng mach phoi hgp voi sir gia tang CO thi dugc trung hoa thong qua tac dung fibrinogen,
tren cac bach cau. Trong cay mo, cac acide beo tu do lam tang tong hgp fibrinogen boi cac nhat cat gan nguoi.
* Trong dap ting viem :
Heinrich .1 va Assmann G fibrinogen dong vai tro sinh mang xa vua mach mau thong qua nhieu co che :
- Xiic tien xo vua dgng mach, co vai tro Su gia tang fibrinogen huyet tuong la true tiep len sir thoai hoa mach mau.
mgt phan chu }'eu cua phan iing protein - La mgt yeu to chinh cua sir ngung tap huyet tuong trong giai doan cap (sau ton tieu cau, fibrinogen lam tang sir ket dinh tieu thuong, phau thuat. nhiem triing cap. cac cau bang each ket hgp vai cac thu the tieu nhoi mau nao hoac tim cap). Trong mgt vai
gia dau cua cac su co nay, sir tong hgp fibrinogen ciia gan va cac protein giai doan cap khac tang do su kich thich ciia cac san pham thoai giang fibrin va hoac cac dan bao bj hoat hoa trong cac mo ton thuang Nong do fibrinogen huyet tuong thuang dat dinh cao 2-4 lan mirc binh thuong sau 3-5 ngay, truac khi dan tra \'e mirc binh thuang khi dap img
\icm cham dirt.
Sir gia tang fibrinogen huyet tuang qua cao CO the lam tang ngung tap hong cau, thiic day sir ket dinh bach cau trong cac mach mau
cau va phong thich ra ADP, Serotonine, PF4 vi tieu cau tang cac thii the ciia minh.
Fibrinogen tang cao xiic tac lam tang su ket dinh tieu cau. Tieu cau ket dinh gan fibrinogen vai Gpllb-llla tao phuc hgp hoat dgng. no c6 vai tro rat lan lam tang tinh trang dong mau.
- Fibrin lang dgng va kich thuoc ciia cue mau dong lien quan true tiep den nong do fibrinogen huyet tuang.
- Fibrinogen lam tang do nhat huyet tuang.
- Anh hucmg ciia tieu cau va fibrinogen nho \'a do do co su tham gia cua chimg vao tang lam tang dap img ciia eytokin dugc giai dap irng \iem. Neu nhu cac dap img \iem phong tir mang vua ciia thanh mach boi cac khong cham dirt (nhii' trong cac nhiem triing don bao.
man. cac benh ly \ieni vo triing man nhu Cac mang xo vira bao g6m lipid, viem da khop dang thap hoac cac benh ly ac glycosaminoglycan, cac thanh phln te bao tinh) thi hau qua la co su tang fibrinogen khac nhau, fibrinogen, fibrin va cac san pham huyet tirong man tinh. Vi fibrinogen la mgt thoai giang cua chiing. Su hinh thanh "huyet phan tu lan. thon dai nen sir gia tang man kh6i xa vira" la mgt vong luin quin. Bit dau
voi su thay doi thanh mach bai cac kich thsich man din den mgt dap iing cap nhe, tang nong do fibrinogen va thay dli can blng cam mau huong din hinh thanh huyit khii va tang lang dgng sgi huyit. Fibrinogen tham vao thanh dgng mach, tac dung nay dugc lam tang len bai cac dong yeu to lam t6n thuang mach nhu hut thuoc la. Su hoat hoa qua trinh tieu sgi huyet sau do san sinh ra cac san
pham thu hiit cac te bao, dan den tich tu lipid va phat trien mang vira. Fibrin tao nen bl mat hilt lay su tich tu cua cac lipid trgng lugng phan tir thap LDL, ke nirt cua mang vira dugc tao thanh lai gay nen mgt dap img giai doan cap, va lap lai vong luan quan nay.
Ket qua cuoi cimg cua nhieu chu trinh nay la sir huyet khoi tic mach.
So do 1: Vai tro cua fibrrinogen, cac yeu to dong mau va lipid 2.4. Giai doan dong mau
Dong mau la qua trinh mau chuyen tir the long sang the dac, do sir chuyen fibrinogen thanh fibrin khong hoa tan va cac sgi fibrin nay se tao ra mang luoi giii cac thanh phan cua mau tao nen cue dong. Cac mau dong hinh thanh co cac tac dung bit b'n cho ton thuang mgt each vimg chac.
Cac yeu to dong mau dugc chia thanh mot so nhom chinh:
- Nhom cac yeu to tiep xuc: Gom cac ylu tl XI, XII, prekallikrein. Cac ylu t l thuoc nhom nay dong vai tro chinh trong giai doan tilp xiic cua qua trinh dong mau, khong cin su CO mat ciia ion canxi ciing nhu vitamin K dl co hoat tinh dong mau.
- Nhom Prothrombin: Gom cac yeu to 11, VII, IX, X CO dac diem chung la can sir co mat ciia vitamin K mai co tac dung dong mau bai vitamin K lam cho cac yeu to nay co kha nang gan vai ion canxi. Vi vay, con co ten ggi la nhom cac yeu to phu thuoc vitamin K.
- Nhom fibrinogen: Gom fibrinogen, V, VIII, XIII: Dac diem chung ciia nhom nay la chiu tac dung cua thrombin, kem ben vimg va bi tieu thu het trong qua trinh dong mau nen invitro khong co mat trong huyet thanh.
Cac giai doan cua qua trinh dong mau:
Nam 1905, Moravitz dua ra so do dong mau bao gom 3 giai doan chinh: Giai doan hinh thanh prothrombinase, giai doan hinh thanh thrombin va giai doan chuyen
fibrinogen thanh fibrin duai tac dung ciia thrombin.
Ngay nay, ve ca ban, sa do ciia Moravitz van dung nhung dugc phat trien, bo sung them nhieu. Nam 1960 co hai nhom tac gia da dua ra mgi mo hinh dong mau. Theo mo hinh na\\ qua trinh dong mau dugc hinh dung la mgt chu6i noi tiep cac phan img men, trong do su hoat hoa ciia mgt yeu to dong mau se dan den sir hoat hoa ciia yeu to dong mau tiep theo va cuoi ciing dan den sir hinh thanh fibrin. Mo hinh nay lai tiep tuc dugc nhieu tac gia bo sung sau khi phat hien rang mgt \ai \eu to dong mau dugc thuc ra la khong CO hoat tinh men va mgt vai yeu to khac la cac dong yeu to.
- Giai doan hinh thanh thromboplastin hoat hoa (phuc hgp protlirombinase).
Day la giai doan phii'c tap nhat. Bao gom hai con duong hinh thanh thromboplastin hoat hoa: Ngi sinh va ngoai sinh. Cac yeu to tham gia duang dong mau ngi sinh c6 trong long mach. con mgt so yeu to tham gia duang dong mau ngoai sinh khong ton tai trong mau luu hanh trong dieu kien sinh ly binh thirong. Day chinh la ly do hinh thanh nen ten ggi ngi hay ngoai sinh .
+ Duong ngi sinh: mach mau bi ton thuang. mau tiep xuc vai to chuc duai ngi mo dugc bgc Ig nhu collagen hoac cac thaiih phan mang ca ban khac va do vay, khai dgng qua trinh hinh thanh thromboplastin hoat hoa duong ngi sinh. Trong qua trinh nay, yeu to Xll trai qua mgt su thay doi cau triic a be mat. bgc 16 \i tri hoat hoa cua phan tir va nha
\a>' no tro thanh dang hoa hoa (Xlla). Den lugt minh, Xlla co tac dung chuyen zymogen prekallikrein thanh dang hoat hoa kallikrein, kallikrein lai chu}en yeu to XI thanh Xia.
Nhiing buoc hoat hoa nay yeu cau su noi ciia zymogen vai kininogen trgng lugng phan tu cao. Moi klii dugc tao thanh, yeu to Xia chuyen yeu to IX a dang zymogen thanh ylu to IX hoat hoa (IXa). Yeu to IXa ciing voi dong yeu to Villa, ion Ca""^ va phospholipid tao phirc he prothrombinase (Villa la dang hoat hoa ciia dong yeu to Vlll duai tac dung ciia thrombin).
+ Duong ngoai sinh: Khi mach mau bj ton thucmg, thromboplastin to chii'c dugc giai phong va c6 tac dung hoat hoa yeu to VII thanh Vila, vai sir co mat cua ion Ca"^"^ co tac dung boat hoa yeu to X thanh Xa. Yeu to X hoat hoa se ciing yeu to to chirc, ion canxi va yeu to V boat hoa hinh thanh phirc hgp prothrombinase.
- Giai doan hinh thanh thrombin
Thromboplastin hoat hoa (phirc hop prothrombinase) dugc tao thanh bang duong ngi sinh va ngoai sinh deu c6 tac dung chuyen prothrombin thanh thrombin vai su tham gia ciia ion canxi. lon canxi co kha nang gan duoi carboxyglutamic ciia prothrombin va yeu to Xa, nha vay lam cho phirc he nay de dang tap hgp lai tren be mat phospholipid mang te bao mang dien tich am
dien hinh la be mat mang tieu cau. ' - Giai doan hinh thanh fibrin ' Duai tac dung ciia thrombin, fibrinogen
trai qua mgt qua trinh bi cat co chgn lgc cac fibrinopeptide A va B tii' cac chuoi A - a va : B - p tuang irng, sau do cac monomer fibrin triing hgp thanh cac fibrinpolymer. Liic dau, cac sgi fibrin lien ket bang cac cau noi hydro long leo. Duai tac dung ciia ylu t l Xllla, cac cau noi hydro long leo dugc thay bang cac cau noi dong hoa tri, tao nen luoi fibrin ben vung.
C o n di/cmg n 6 i s i n h C o n difctng n g o » i s i n h ^ Mau trfn thirong hofic tiSp
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T h r o m b i n —> ,]/ >]/ 4.
(4) X / : > x .
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-» «- -XIII
I^Lfdi Fibrin
So do 2: Co che cua su hinh thanh Prothrombinasse (Theo con dudng ngogi sinh vd con dudng ndi sinh) Thuc te cho thay phan chia qua trinh dong
mau thanh cac giai doan, cac con duong dong mau rat him ich trong danh gia, chan doan va dieu tri cac roi loan dong mau. No giiip chiing ta nhanh chong dinh huong, khu tni va sau do dinh ro nguyen nhan gay roi loan qua trinh dong mau.
Day Cling chinh la ca so cho viec hinh thanh va ap dung cac ky thuat xet nghiem danh gia tinh trang he thobg dong mau trong lam sang ciing nhu nghien cim. Tuy nhien, trong co the con nguoi, khong CO sir doc lap, tach bach rieng re cung nhu dien biln t u ^ hr giiia cac con duong dong mau ngi, ngoai sinh va duang dong mau chung, ma thuc te cac con duong nay luon anh huang lln nhau, tuong tac lan nhau, dan xen nhau va dac biet la bl sung cho nhau. Quan niem nay giiip chiing ta
ly giai vi sao mgt tinh trang thieu hut ylu to XI hoac yeu XII lai hau nhu khong co trieu chiing chay mau tren lam sang. Quan niem nay cung la CO so cua cac nghien ciiu vai tro cua yeu to Vila trong tham gia duang dong mau ngi sinh. Ket qua cua cac nghien ciiu nay la san xuat va sir dung rgng rai cua cac che ph&n Vila tai to hgp (Novoseven) trong dieu tri Hemophillia A the nang, co lie che VIII, giam tieu cau nang.
2.5. Tang huyet ap ngung tap tieu cau va dong mau
Thuc nghiem ciing nhu tren lam sang deu xac nhan tac hep dgng mach do huyet khoi la mgt bien chiing thuang gap va gay hau qua nang ne a benh nhan tang huyet ap.
Nhu vay mac dii ap luc mau tang cao, bien
dgng \ a keo dai nhung bien chimg chinh a nhung benh nlian na} lai do huyet khoi gay nen chir khong phai do chay mau. Nhieu cong trinh nghien cim da cho thay mgt tinli trang tang hoat hoa he thong dong cam mau dan den hu\lt khoi gay tac hep dgng mach a benh nhan tang huyet ap. C> benh nhan tang hu\lt ap CO day du cac yeu to gay huyet khoi trong thu nghiem ciia Virchow: Bat thuang thanh mach, bat thuang dong chay ciia mau, bat thuofng cac thanh phan mau.
Bk thuang thanh mach: C» benh nhan tang huyet ap, ap luc ciia tang cao va keo dai do do Iam thay doi cau true ciia thanh mach:
Lap CO day Ien. to chirc lien ket phat trien, dac biet la te bao ngi mac giam hoac mat chirc nang . Khi ngi mac bi ton thuang, bgc Igc to chu'c duoi ngi mac, tieu cau nhanh chong dinh vao cac to chirc duai ngi mac vira dugc bgc Ig qua tuang tac giira yeu to von Willebrand va GPIb. Mat khac, collagen va thrombin (dugc tao thanh bang duang dong mau ngoai sinh do ngi mac bi ton thuang) kich thich su hoat h6a tieu cau, tang cuong bai tiet acide arachidonic, tao thromboxan A2. ADP dugc bai tiet tir cac tieu cau da hoat hoa CO tac dung lam cho tieu cau boat hoa manh them. Ket qua ciia qua trinh nay la tieu cau ngung tap khong hoi phuc. tao niit cam mau trang. Su xuat hien hay khong va a mirc do nao cua cue mau do giau fibrin va hong cau phu thuoc vao mirc do ton thuong nong hay sau, tinh trang mach mau truac khi bi ton thuong (binh thuang hay da co ton thuang san. CO lang dgng cholesterol khong...). Khi tcMi thuong a mirc chi bgc Ig ngi mac, khong ton thuang trung mac, tieu cau ngung tap thanh dam. khong c6 hien tugng tao fibrin.
Khi ton thuang a mirc do sau ban, trung mac dugc bgc Ig thi ngoai tinh trang ngung tap ticu can. con co hien tugng hinh thanh fibrin.
nghia la ngoai tinh trang hoat hoa tieu cSu.
dong thac dong mau cung dugc boat hoa.
Mat khac, mirc do thay doi cau triic dong mach a THA con dugc tang cuong bcVi mot so yeu to suy ca di kem nhu roi loan lipid mau. dai duang. hut thuoc. Vi \'ay cac biln chirng tac hep mach do hu\et khoi a nhimo benh nhan THA c6 ket hgp cac nguy co nay thuang gap \'a nang ne han so voi nhirng benh nhan THA don doc.
- Tang huyet ap va thay doi dong chay:
Tang huyet ap Iam hep long mach, giam tinh dan hoi do nhieu nguyen nhan: Do co mach boi giam san xuat cac chat gian mach tir cac te bao ngi mac mat chuc nang, do su co mat ciia cue dong giau tieu cau... Giam tinh dan hoi thanh mach, hep long mach lam thay doi dong chay ciia mau cr nhiing benh nhan THA.
Ci benh nhan THA, dong chay hon loan xuat hien, lire dich chuyen khu tni tang len, tang tuang tac giiia cac tieu cau dan den tinh trang tieu cau tang hoat hoa: tang dinh, ngung tap, bai tiet... Hau qua la hinh thanh cue dong giau tieu cau (cue mau trang). Thay doi dong chay ciia mau cung la nguyen nhan gay tang boat hoa qua trinh dong mau: Duong dong mau ngi sinh tang boat hoa bai tang hoat hoa nh6m cac yeu to dong mau tiep xiic.
Duong dong mau ngoai sinh hoat hoa bai ap luc mau tang cao va bien dgng lien tuc gay ton thuang te bao, ton thuang mach mau do do giai phong thromboplastin to chii'c...
- Tang huyet ap va thay doi cac thanh phan mau:
Nhung bat thuang cac thanh phan ciia mau trong thii' nghiem ciia Virchow cung luon gap a benh nhan THA, do la tinh trang tang hoat hoa tieu cau, tang nong do, hoat tinh cac yeu to dong mau va giam hoat hoa he thong tieu sgi huyet.
+ Tang hoat hoa tieu cau a benh nhan
tang huyet ap dugc xac nhan la mgt chi dilm ciia bien chiing tic mach 6 nhiing benh nhan nay. Nghien cim ciia Keidar S, Oiknine J.
cho thay tang boat hoa tilu cau xuk hien sum a benh nhan tang huyet ap va d6ng vai tro quan trgng trong su khai dhu qua trinh xa mo dgng mach.
Tang boat hoa tieu cau la mgt yeu to thuc day bien chiing tac mach a tang huyet ap. Su tang hoat hoa tieu cau khong tro ve binh thucmg khi benh nhan da dugc dieu tri tang huyet ap. Vi vay, mgt so nha nghien ciiu cho rang can dieu tri thuoc lie che boat hoa tieu cau song song thuoc ha huyet ap doi voi nhiing benh nhan nay. Tinh trang tang boat h6a tieu cau xay ra a benh nhan THA do nhieu yeu to gay nen: Giam san xuat cac chat lie che ngung tap tieu cau, tang so lan va cham giiia cac tieu cau boi thay doi chi so dich chuyen...
+ Tang nong do va tang hoat hoa cac yeu to dong mau:
Tang nong do va tang hoat tinh cac yeu to dong mau thuang gap trong THA. Tang nong do cac yeu to phu thuoc vitamin K: yeu
to II, VII, IX va yeu to X dugc xac nhan qua nhieu nghien ciiu tren thuc nghiem ciing nhu tren lam sang. Dae biet, tang nong do fibrinogen thuang gap a benh nhan THA va la mgt trong nhung yeu to nguy co tim mach ngay cang dugc quan tam. Q nhirng benh nhan THA c6 nong do fibrinogen tang tren 350mg/dl thi nguy ca tim mach tang gip 12 lan so vai benh nhan tang huyet ap co nong do fibrinogen binh thuang.
Chinh vi vay, roi loan dong cam mau thuang gap a benh nhan tang huyit ao la tinh trang tang dong, tao huyet khoi, gay tSc hep dgng mach gay nen cac bien chimg nang ne: tac hep dgng mach vanh gay cac benh ly mach vanh nhu dau that nguc, nhoi mau ca tim, tac dgng mach nao gay nhoi mau nao, tac hep dgng mach ngoai vi nhu dgng mach diii... Day co le la nguyen nhan giai thich vi sao dieu tri giam huyet ap khong phai luon cho ket qua song song vdi giam cac bien chiing tic mach. Dieu tri chong dong va ire che boat hoa tieu cau da cho thay ket qua trong du phong va dieu tri t4c mach a nhimg benh nhan nay.
2.6. Roi loan lipid mau, ngung tap tieu cau va dong mau fl. Phan loai roi loan lipid mdu
Bang: Danh gia bilan lipid theo ATP III (2001)
Thanh phan
TC
HDL
LDL
Nong dp mg/dl
<200 200-239
>240
<40
>60
< 100 100- 129 130- 159 160- 189
> 190
(mmol/l)
<5,2 5,2- 6,2
>6,2
< 1
>1,6
<2,6 2,6- 3,4 3,4- 4,2 4,2-5
> 5
Danh gia nguy ctf
Tot
Cao gidi ban Cao
Thap Cao Toi Uu Gan toi Uu Cao gidi han Cao
Rat cao
TG
< 150 150- 199 200- 499
>500
<1,7 1,7- 2,3 2,3- 5,7
>5,7
Binh thudng Cao gidi han Cao
Rat cao Giira roi loan lipid va he thong dong cam
mau CO mgt moi lien quan chat che, dieu nay da dugc nhieu nghien cim tren thuc nghiem cung nhu thirc te lam sang chiing minh.
Tang cholesterol, tang phospholipid a mang tieu cau \a do vay tang tuong tac giua cac tieu cau d nhung benh nhan roi loan lipid.
Hau qua la cac tieu cau tang boat hda, Iam tang qua mirc can thiet trong qua trinh tao niit cam mau k\' dau cung nhu trong giai doan dong may hu>'et tuong. Kiem tra tinh trang hoat hda tieu cau tru'dc va sau dieu tri rdi loan lipid mau cho thay giam ndng do cholesterol bdi che do an kieng va bdi thudc deu Iam giam song song mirc do hoat hda tieu cau.
Anh hudng ciia lipoprotein LDL- C len tinli trang hoat hda tieu cau cung da dugc xac nhan bdi thuc nghiem danh gia miic do boat hda te bao na\- tardc va sau khi ii lipoprotein nay vdi tieu cau da dugc rii'a sach bdi dung dich dem.
Cac thudc ire che ngung tap tieu cau cung da chirng minh cd hieu qua trong du phdng thu- phat cac bien chimg ciia cac tdn thuong \ua xa ddng mach d mach vanh.
mach nao \a dgng mach chi dudi. Ngoai tieu cau. cac )eu td tham gia he thdng ddng mau
\'a tieu sgi hu>et cung cd nhung thay ddi rd ret d benh nhan rdi loan lipid.
Tang cholesterol mau Iam tang ndng do cac marker te bao ndi mac trong huyet tuong nliu thrombomodulin, yeu td von Willebrand cung nhu cac marker ddng mau: TAT (thrombin - antithrombin III), FPA (fibrinopeptid .\). Tang triglyeerid mau lam tang hoat hda qua trinh ddng mau bdi tang
hoat hda cac yeu td Vll, VIII va yeu tl X ciing nliu ire che qua trinh fibrin do tang tilt PAI - 1. ire che hoat tinh t- PA. sir mdt can bang nay dira den hau qua la hinh thanh hii}'et khdi. Mat khac, lipoprotein (a) mang nhieu cholesterol, apoprotein (a), do cau true ciia apoproteins (a) gidng cau true plasminogen nen canh tranh vdi chat nay, hau qua la lam suy yeu he thdng tieu sgi huyet va de dang tao huyet khdi do cue mau ddng khdng dugc tieu di kip thdi. Tang lipid ciing thuc day hirih thanh huyet khdi bdi tang boat hda cac yeu td ddng mau phu thuoc vitamin K (II, VII, IX, X). Qua kit qua nghien cim tren 40 benh nhan rdi loan Iipid,Moishita ket luan cd mdi tuong quan chat che giiia ndng do cholesterol va nong dp yeu td VII, IX. Nghien ciai nay ciing cho thay tinh trang suy yeu ciia he thdng tieu sgi huyet d nhung benh nhan tang triglyeerid bdi tang cao ndng do chat uc che boat hoa plasminogen (PAL Plasminogen Activation Inhbitor).
b. Ddng cdm mdu 6 benh nhdn tai bien mach mdu ndo tdng huyet dp cd rdi loan lipid
Nhieu nghien ciin tren the gidi va d Viet Nam xac nhan THA va RLLP diu la yeu to nguy ca quan trgng gay benh Iy tim mach va thudng ket hgp tren ciing mdt benh nhan.
Su ket hgp hai yeu td nguy ea nay lam tang them cac rdi loan ddng cam mau do THA va do RLLP gay nen. Hau qua la tinh trang tang dong mau xay ra manh han, nguy ca tac hep mach do hu}'et khdi cao hon THA hoac RLLP mdt minh
Tao huyet khdi cd thi xay ra tren mdt mang viia xa bi loet hay khdng bi loet. Dau tien la huyet khdi trang - giau tieu cau - sau do la huyet khdi hdn hgp. Trong cac ddng mach cd dudng kinh lan, huyet khdi van dinh vao thanh mach va lam hep long mach.
Trudng hgp huyet khoi bi bong ra va di chuyen se tao hien tugng thuyen tac do cue mau ddng - hay gap tren mgt co dia vira xo nang va cd cac yeu td thuan lgi nhu can thiep ngoai khoa... Trong cac dgng mach vira va nhd, huyet khdi gay tac hoan toan long mach dan den cac tai bien thieu mau cue bg.
Nhu vay, huyet khoi va hep tac dgng mach la nhiing bien chiing thudng gap va gay hau qua nang ne d benh nhan tim mach noi chung va benh nhan THA ket hgp RLLP noi rieng. Nguyen nhan gay nen cac bien chimg nay la tinh trang rdi Igan ddng mau
nghieng ve tang ddng do da yeu td: Tdn thuong thanh mach, tang hoat hda tieu cau, tang boat hda dgng mau, suy yeu he thdng tieu sgi huyet.
I I I . KET LUAN
Hien nay dot quy van la mgt van de khd khan trong y hgc vi ty le tir vong tir vong cao va de lai hau qua nang ne .Mac dii da cd nhieu tien bd trong chan doan va dieu tri viec di sau nghien cuu ve tieu cau de danh gia chiic nang,vai trd tieu cau va mdi tuong quan vdi fibrinogen, lipide, tang huyet ap, qua dd giiip thay thudc sir dung thudc chdng ddng va chdng ngung tap tieu cau ket hgp thudc ha huyet ap, thudc giam lipide mau mgt each hgp ly, dung thdi diem, dieu chinh lieu phu hgp, hieu qua trong giai doan cap va/hoac trong du phdng thir cap dot quy tai phat.
