JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY Vol.12 - ti'S/lOM
Danh gia su* bien ddi chuc nang thi giac trong dieu kien giam ap - thilu oxy 6* d6i tuang dy tuyin phi cong tai Vien Y hoc Phong khong - Khong quan nam 2016
Assessment of visual functions in normal and in hypoxic pressure- reduced condition inrecruiting pilots at the Institute of Air Defense Medicine in 2016
Vii Quoc Chi§n*, *Vien Yhgc Phdng khdng - Khdng qudn Nguyen Dire Anh** **Trudng Bgi hoc YHd Not Tdm tSt
Muc tiiu: Danh gia mpt sd chUe nang thj giac trong dieu kien blnh thudng va dieu ki^n giam ap - thieu oxy va nhan xet m6t so yeu td lien quan den sU bien doi thj giac trong dieu kien giam ap - thieu oxy. Ddi tugng va phdang phdp: Nghien cUu tr&n 53 nam thanh nien tudi tU 17 den 20 du tuyen phi c6ng tai Vien Y hpc Phong khong - Khong quan nam 2016. Sd dung budng g i i m ap de tao mdi trudng gici lap giam ap - thieu oxy tuong duong d d6 cao 5000m trong 30 phut va danh gia chUc nang thi giac trong dieu kien nay. Kit qud: ChUc nang thi giac suy giam theo thdi gian va khac nhau d eac doi tupng khac nhau. Ty le cd bien ddi chUc nang thj giac la 39,6% sau 5 phut, 47,2% sau 15 phut, va 77,4% sau 25 phOt.
d phut thuf 25 can diem quy tu xa mat hdn ban dau la 0,75 ± 0,6cm; bien dp dieu tiet giam 0,96 + 0,9D;
thi lUc lap the giam 24,2 + 2,6"; thj lUe nhin gan giam 1,1 ± 0,6 ddng. Su bien ddi chdc nang tang theo thdi gian, vacd lien quan den he sd phdi (58,5 ± 2,9 d nhdm cobi^n ddi chijfc nang thi giac va 61,2 ±0,95 d nhdm khdng c6 bien doi chUe nang thj glae), 69,4% cd bien doi d nhom ren luyen the thao thUdng xuyen, khdng ren luyen the thao cd bien ddi 94,1 %. Kit ludn: Luyen tap thUdng xuyen de nang cao sdc chju dUng trong dieu ki^n giam ap - thieu oxy la thUc sU can thi^'t vdi phi c6ng va hpc vien hpc lai m^y bay. Danh gia bien doi thi giac trong dieu kien giam ap - thieu oxy cd can thiet ddi vdi viec tuyen chpn, giam dinh sdc khde phi cdng va an toan bay.
Tdkhda: Bien ddi thj giac, gi^m ap - thieu oxy, tuyen phi cdng.
Summary
Objective: To assess some visual functions in normal and hypoxic pressure-reduced condition and to review/ factors related with visual changes in this condition. Subject and method: A study of 53 young men aged from 17 to 20 w/ho attended pilot recruitment at the Institute of Air-Defense Medicine. Use of a pressure-reducing chamber to create a hypoxic pressure-reduced quivalent to a height of SOOOnn in 30 minutes and to evaluate visual functions under this condition. Result: Visual function decreased over time and varied in different subjects. The rate of visual function changes w/as 39.6% after 5 minutes, 47.2% after 15 minutes, and 77.4% after 25 minutes. At minute 25, near point of convergence decreased
Ngdy nhgn bdi: 25/7/2017, ngdy chap nhdn ddng. 02/8/2017
Ngudi phdn hdi: VH Quoc Chiin, Email: chienvuhs68@gmailcQm - Vien Y hQC Phdng khong - Khong qudn
TAPCHlYDaOCLAMSANGlOS Tap 12-S6 8/2017 by 0.75 ± 0.6cm, amplitude of accommodation decreased by 0.96 ± 0.9D, stereoscopic vision decreased by 24.2 ± 2.6", loss of near VA was 1.1 ± 0.6 lines. The changes w/ere increased over time, and associated with lung coefficient (58.5 ± 2.9 in the group with visual function changes and 61.2 ± 0.95 in the group without changes). 69.4% had regular sports training, 94.1% did not have regular sports training.
Conclusion: Regular exercise to improve strength in hypoxic and presure-reduced condition is essential for pilots. Assessment of visual changes in hypoxic and presure-reduced condition is essential for the selection of pilots and flight safety.
/Ceywords: Visual changes, hypoxic pressure-reduced, pilot recruitment.
1, Dat v a n de
Thj giac cd vai trd quan trpng trong viec dam bao an toan bay. Trong dieu kldn bay chien dau va huan luyen chien dau, eac phi cdng se phai gid dupe kha nang thj giac tdt trong dieu kien thay ddi gia tdc va dac biet la sU thay doi ap suat khi quyen. Khi len cao ap suat khi quyen giam ddng nghla vdi viee thieu oxy gay rdi loan van ddng vd nao, tac ddng den eac chufc nang phSn tieh quan, lam rdi loan thi giae - la chdc nang cd tam quan trpng dac biet vdi cdng tac bay nhU: Quan sat muc tieu tren tren khdng, tren mat dat {dja tieu), doc ddng hd bay, tin hieu den, ban do bay [3]. Rdi loan chdc nang thi giac bat dau xuat hien d dp cao 1500 - 3000m. Su bien ddi ro ret tU dp cao 5000 - 6000m, hau nhu tat ca cac chUe nang thj giae bj bien ddi: Thi trudng thu hep, giam thi lUc, giam cam giac ve mau sle, kh^ nang ^ e u tiet va quy tu giam, xuat hidn thieu mau vong mac, lac an tang, cd the xuat hien song thj hoae can thl tren cao [3], [7], [9]. Theo Tran Van Xuan va cdng sU (2010) d do cao 5000m, thi giac chieu sau va lac an cua phi cdng cd su bien ddi theo thdi gian. Theo Kowalczuk va cdng su (2016), khi lam viec trong dieu kien ap suat thap, thieu oxy, chufc nang thj giac cua phi cdng thay ddi manh me trong d d cd rung giat nhan cau, gi^m nhay cam anh sang, rdi loan ehde nang thj giac hai mat, thi giac lap the, s^c giac [10]. Kiem tra sde
chju dung t r o n g dieu kien giam ap - thieu oxy tai budng gi^m ap la ndi dung bat budc ed tinh chat dac thu trong kham tuyen sUc khde phi cdng [1], [2], d Viet Nam chua ed nghien cUu nao ve van de nay tren ddi tUpng dU tuyen phi cdng, vl vay chung tdi nghien edu de tai nay vdi mue tieu: (1) Ddnh gid mot sd chdc ndng thi gidc trong diiu kien binh thddng vd trong dieu kien gidm dp - thieu oxy; (2) Nhdn xit mot so yeu td Hin quan din sd biin doi thi gidc trong diiu kien gidm dp - thieu oxy.
2. Ooi tufcrng va phUtfng phap 2.1. Ddi tugng
Nghien cdu bao gdm 53 nam thanh nien tudi t d 17 den 20, tham gia dUtuyen phi cdng tai Vien Y hpc Phdng khdng - Khdng quan trong thdi gian t d thang 10 den thang 12 nam 2016.
2.2. Phuang phdp 2.2.1. Phuang tiin nghien cdu
Cac phUdng tien sd dung trong nghien cdu nay gdm: Budng gicim ap (Hlnh 1), b^ng thj luc Snellen, being thj luc nhin gan, bang thj luc lap the Randot stereo test (sU dung vdi kfnh phan cUe, cho phep do thj luc lap the tU 500" den 20"), den but kham m^t, thudc do dp dai cm.
^KM, %
Hinh 1. Budng gicim ap
JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY
2.2.2. Cdc budc tien hdnh
Cac ddi tupng nghien edu dUpc kiem tra de dam bao du dieu kien an toan tham gia t h d nghiem trong dieu kien giam ap - thieu oxy. Cac yeu cau kiem tra ehde nang thj giac can ban gdm: Thj luc nhin xa, thj lue nhin gan, sac giac, quy t u , bien dp dieu tiet binh thudng, khdng ed benh cap va man tinh d mat. Cac chdc nang khae da dupe kiem tra d cac chuyen khoa tuong Ung [1], [2].
Sau dd, eae ddi tUdng ddgc pho bien eae quy djnh bao dam an toan trong thdi gian t h d nghiem trUdc khi vao budng gicim ap. Trong budng giam ap, khdng khi se dUpc rut ra tao mdi trudng giam ap - thieu oxy tUPng tU nhu dang len cao vdi tdc dp 15m/giay, thdi gian d dp eao 5000m la 30 phut, khdng tinh thdi gian Idn va ha dp cao [6].
0 do eao 5000m, tai eae thdi diem 5 phut, 15 phut va 25 phut cac ddi tupng duac kiem tra thj giac lap the, thj luc gan, quy t u , bien dp dieu tiet. Bac sT thUc hien cac lenh dieu khien qua bd dam, giam sat qua kinh va man hinh camera, ngUdI hUdng dan trong budng giam ap (nhan vidn y te chuyen trach) 6 trong budng cung cac ddi tupng dU tuyen se true tiep trp giup trong qua trinh kiem tra.
Sau khi trd ve dieu kien blnh thUdng (ra khdi budng) cac ddi tupng dUpc khiem tra lai cac chdc nang.
2.2.3. Cdc ch! tiiu nghiin cdu
Do dac diem dac thu cua budng giam ap va gidi han ve thdi gian nen ehung tdi khao sat mdt so chi tieu sau:
Dae diem cua ddi tUpng nghien cdu: Tudi, ndi sdng, tidn sd benh tat ve mat, hoat ddng the thao, dung tich phdi, he sd phdi (Demine) = Dung tfch sdng (ml)/Can nang (kg) [1], [2], [8].
Cae ehUc nang dUpc kiem tra trong dieu kien binh thudng (phdng kham mat), khi d dp cao 5000m (trong budng gi^m ap) phut thU 5, 15, 25; ngay khi trd ve dieu kien blnh thudng (ra khdi budng gi^m ap). Cac chdc nang bao gdm:
Thi luc nhin gan.
Thj luc l|p the.
Can diem quy t u . Bien dp dieu tiet.
2.3. Thiet kenghien cdu vdxCflidd lieu Nghien cdu theo thiet ke md ta, cat ngang. DGf lieu dupe phan tich va xd If bang phan mem SPSS 21.0.
3. Ket qud va ban luan
3.1. Dgc diem cda cdc doi tuang nghien cdu Nghidn cdu bao gdm 53 nam thanh nien, tuoi trung binh la 17,45 ± 0,82 tudi. Sd ddi tUdng den xii ndng thdn la 36 ngUdl (67,9%), sd den t d thanh thi la 17 ngUdi (31,9 %). Chieu eao trung binh la 170 ± 3,2cm, BMI trung binh la 21,5 ± 2,1, dung tieh sdng 3709 + 346ml, he sd phdi trung binh 59,1 ± 2,9. Tat c i deu dCi dieu kien an toan ve sdc khde khi len dp cao 5000m.
Bdng 1. Dac d i e m ve ren luyen t h e t h a o va he so p h o i cua cac d d i tugrxg nghidn cufu
Ndi d u n g Ren luyen the thao
H§ sd phoi (Deminer) Co Khong
a 60
<60 n 36 17 25 28
T y l f % 67,9 32,1 47,2 52,8 Cd 67,9% ren luyen the thao thudng xuyen, 47,2% ed he sd phdi > 60.
3.2. Chdc nang thi gidc trong dieu kien binh thddng 3.2.1. Thi luc vd thi gidc lap the
Bang 2. Thi life va t h j life lap the Chi^c nang
Thi lire nhin xa Thi luc nhin gan Thi IKC lap
then
Nl N2
< 8 0 "
> 8 0 "
n 53 50 3 45 8
T y l e % 100 94,3 5,7 84,9 15,1
MuTc do 2 20/20 TB 1,06 ±0,23 TB 59,6 ± 25,r,
min 20", max 140", mode 70' 100% ddi tupng ed thi lUc nhin xa 2 mat >
20/20, thi lUc nhin gan d mufc Nl va N2. Thj lUe lap the trung blnh (TB) la 59,6 ± 25,1".
3.2.2. Quy tu vd diiu tiit Bdng 3. Quy t u va dieu t i e t ChuTc nang
Can diem quy tu Bien do dieu tiet
K^t qua do 7,0 ± 1,3cm 12,5±2,0D Can diem quy tu va bien dp dieu tiet trong gidi ban blnh thudng hoac tdt hdn.
TAPCHlYDaOCLAMSANGlOS Tap 12-So 8/2017
3.3. Bien doi chdc ndng thi gidc 3.3.1. Bien ddi chung
Bdng 4. Sd \dgng ddi tUtfng c6 bien doi chuTc nang thj gidc theo thdi gian
"^— ^_^^ Thdi diem Chiic nang ~~-——-,___
Thay doi Khong thay doi
5 phut n(%) 21 (39,6) 32 (60,4)
15 phiit n(%) 25 (47,2) 28 (52,8)
25 phut n(%) 41 (77,4) 12(22,6) a do cao 5000m,sd lUOng ddi tUpng cd bien ddi ehde nang thj giac tang theo thdi gian. Cd 12 ddi tUpng (22,6%) hoan toan khdng xuat hien thay ddi nao.
3.3.2. Chi so chdc ndng thi gidc theo thdi gian
Bdng 5. Sd IUtfng va stf bien ddi cac chu'c nang theo thdi gian thieu oxy
^ ^ ^ ^ T h o l d i e m ChiJc nang"~---^^
Quy tu (cm) Oilu tiet (D) Thi lire lap the (") Thi luc gan (N)
5 phut n(%) 21 (39,6) 19(35,8) 17(32,1) 11 (20,8)
So do 7,2 ±1,3 12,2 ±2,0 66,9 ± 27,7 1,3 ±0,4
15 phut n(%) 25 (47,2) 24 (45,3) 22(51,5) 20 (37,7)
So do 7,3 ±1,2 12,0±1,9 70,1 ± 29,6
1,4 ±0,5
25 phut n(%) 41 (77,4) 41 (77,4) 34 (64,2) 31 (58,5)
So do 7,7 ±1,3 11,5 ±1,7 83,8 ±40,2 2,2 ± 0,6 Sd lupng ddi tUpng ed bien ddi tang dan d mdi ehUe nang va tat ca 4 chUe nang deu suy gi^m theo thdi gian thieu oxy. Quy t u va dieu tidt bj bien ddi sdm nhat.
3.3.3. Sdhdi phuc chdc ndng thi gidc
Kiem tra cac ehde nang thi giae khi t r d ve dieu kien blnh thudng (ra khdi budng giam ap) cho ket qua:
100% eac ddi tupng cd chdc nang thj giac t r d ve gia tri ban dau.
3.4. Mot sdyeu to lien quan den sUbien doi chdc ndng thj gidc trong dieu hiin gidm dp - thieu oxy 3.4.1. Thdi gian thieu oxy vd suy gidm chdc ndng thi gidc
Bang 6. Bien do thay doi chufc nang theo thdi gian thieu oxy
"^ Thdi gian Chijfe nang ^^~~~-~----__^
Quy tu (cm) eieu tiet (D) Thl luc lap the (") Thi lac gan (so dong giam)
Bien do thay doi 5 phut
0,25 ± 0,39 0,27 ± 0,4 7,3 ±1,8 0,2 ± 0,4
15 phiit 0,39 ± 0,5 0,47 ± 0,7 10,5 ±1,5 0,4 ± 0,6
25 phiit 0,75 ± 0,6 0,96 ± 0,9 24,2 ± 2,6 1,1 ±0,6
P
<0,05
Bidn dd thay ddi chdc nang thi giac tang dan theo thdi gian thieu oxy (p<0,05), tang nhieu d thdi diem 25 phiit.
3.4.2. He sdphdi vo bien ddi chdc nang thi gidc
Bang 7. He sd phoi cCia nhom co va khong bien ddi chu'c nang thj giac Co bien ddi Khdng bien ddi
H§ sd phdi trung blnh 61,2 ±0,95
Cd sU khac biet giufa hd sd phdi cda nhdm cd bien ddi va nhdm khdng bien doi chdc nang thi giac (p<0,05).
JOURNAL OF 108 - CLINICAL MEDICINE A N D PHARMACY VoL12-N''8/2017
3.4.3. Liin quan gida mdc do ren luyen thi thao vdi bien doi chdc ndng thi gidc
Bang 8. Mi^c dd ren luyen the thao va bien ddi churc nang thj giac
^ \ ^ Nhdm The thao ^ \ ^ Ren luyen thudng xuyen Khongthudng xuyen
Co bien ddi n(%) 25 (69,4) 16(94,1)
Khdng bien doi
n(%) 11 (30,6)
1 (5,9) Tdng n(%) 36(100) 17(100) Cd su khae biet ve t? le ddi tUpng ed bien ddi chdc nang thi giac gida nhdm ren luyen va khdng ren luyen the thao thudng xuyen.
4. Ban luan 4.1. Dgc diem chung
Cac ddi tupng cd sufc khde tdt, khdng cd bat kl benh tat ve mat, du dieu kien an toan de dua len dd eao 5000m do da dUOe kham sd tuyen sang Ipc sUc khde tai cac dja phuong theo thdng bao cung tieu ehuan ban dau de d u t u y e n phi cong, da Suae kham qua cac vong kham tuyen phi cdng tai Vien Y hpc Phdng khdng-Khdng quan.
4.2. Chdc nang thj gidc trong dieu kien binh thddng Trong dieu kien binh thudng 100% ddi tUpng ed thj luc nhin xa 2 mat > 20/20, thi luc nhin gan d mdc Nl va N2. Thi lUe lap the trung blnh fTB) la 59,6 ± 25,1". Theo Thomas Salmon (2013), thj luc lap the blnh thudng < 80". Ket quci kiem tra cac ehUc nang nay phu hpp vdi chi sd sinh ly eua ngudi blnh thudng va tieu chuan tuyen chpn hpc vien phi edng [11].
Can diem quy tu trung binh la 7,0 ± 1,3em, bien dp dieu tiet trung blnh la 12,5 ± 2,0D. Theo sinh ly thi giac, vdi Ida tudi cua nhdm nghien cufu thl can diem quy tu binh thudng < lOem va bien dp dieu tiet ( 1 5 - 1/4 tudi) trong khoSng 11D den 14D, dieu nay cho thay d dieu kien binh thudng cac chdc nang nay deu d trong gidi han binh thudng hoac tot hon [11].
4.3. Bien doi chdc nang thj gidc Bien ddi chung
6 dp cao 5000m, bien ddi chdc nang thi giac xuat hien d 21 ddi tUpng (39,6%) sau 5 phut, 25 ddi tupng (47,2%) sau 15 phut, va 41 ddi tupng (77,4%) sau 25 phut. Sd lUpng tang len theo thdi gian chju
dung thieu oxy. Tuy nhidn cd 12 ddi tUpng (22,6%) hoan toan khdng xuat hien thay doi nao. Theo Tran Van Xuan va edng sU (2010) danh gia lac an cua hoc vien bay va phi cdng cho thay t;^ le lac an ngang 6 mat dat la 71,7%, tang len la 91,9% sau 10 phiit va 95,9% sau 25 phut. SU bien ddi cac chdc nang thi giac hoan toan phu hpp vdi sinh ly suf dung oxy trong co the khi sU thieu oxy vUOt qua ngudng bCi t r d eua cd the [5]. Hoat ddng co quan c^m gl^e nhir thi giac rat nhay cam vdi sU thieu oxy, d dp cao 5000m ap suat khdng khi la 405,37mmHg, cCia oxy la 52mmHg, trong khi d mat dat sd do tUOng Ung la 760mmHg va 130mmHg [3].
Chisd chdc ndng thi gidc theo thdi gian Theo thdi gian tat c l 4 chdc nang dupe kiem tra deu bien doi ve so ddi tuong va sd do. Vdi cac chu'c nang, ty Id cac ddi tUpng cd bidn doi la khac nhau cae thdi diem tuy nhien deu tang dan theo thdi gian thieu oxy. Quy t u va dieu tiet bi bien ddi sdm nhat, ngay d phut t h d 5, sd lupng lan lupt la 21 (39,6%) va 19 (35,8%). Ket qua do va bien ddi ve quy tu, dieu tidt eung cho thay sU bien ddi chUa anh hUdng nhieu den cac cdng viec binh thudng, tuy nhien khdng the khang djnh ndu lau hdn 25 phut dac biet vdi phi cdng. Dieu nay phu hpp vdi sinh 1^ y hoc hang khdng va khang djnh can phai tuan thd theo quy dinh ve bd sung oxy khi bay d dp cao tren 4000m [3], [9].
Sdhdi phuc chdc ndng thi gidc
Kiem tra cac chdc nang thj giac khi trd ve dieu kien binh thudng (ra khdi budng gi^m ap) cho ket q u i la 100% cac ddi tUpng cd chdc nang thi giaetr6 ve gia tri ban dau. Trong thue nghiem, thdi gian tif luc b k dau ha dp cao den luc ve mat dat khoang 7 phut. Su phuc hdi nay phu hpp vdi sinh ly y hoc hang khdng, phi edng trong khi thUc hanh bay cao tren 5000m cac rdi loan nang thi giac dUpc khac phuc khi cho t h d oxy tinh khiet [3], [7].
4.4. Mot sdyeu to liin quan den sUbien doi chdc nang thi gidc trong dieu kien gidm dp - thieu oxy
Thdi gian thiiu oxy vd suy gidm chdc ndng thi gidc Sd bien ddi chdc nang thj giae theo chieu hudng kem di dien bien theo thdi gian the hien bdi bien dp thay ddi bang hidu sd cda chi sd trong dieu kien thieu oxy qua cac thdi diem va trong didu kien binh thudng. Bien dp nay thay ddi va tang d^n theo 68
TAPCHlYDaOCLAMSANGlOS Tapl2-S6 8/2017
thdi gian (p<0,05), bien ddi nhieu vao thdi diem 25 phut. Qua ket qua nay cho thay thdi gian cang lau thi bien ddi ehufe nang cang nhieu, qua day cung la ca sd de khuyen cao cae phi cdng, dac biet la phi cdng lai true thang, bay d dp cao nay phai tuan thO chat che quy djnh ve sd dung oxy.
He sdphdi vd biin doi chdc ndng thi gidc He sd phoi cCia nhdm cd bien doi chUe nang thj giac la 58,5 ± 2,9 va nhdm khdng bien doi chdc nang thj giac trong sudt 30 phut thieu oxy la 61,2 ± 0,95, sU khac biet cd y nghTa thdng ke (p<0,05). He sd phdi d dieu kien binh thudng anh hudng tdi sU suy giam chdc nang thj giae trong dieu kien giam ap - thieu oxy. Chi sd nay can dat dupc s 60 khi la hpc vien va phi edng lai may bay [1], [2]. Qua day cho thay vai trd cCia hd hap khi d dp cao 5000m anh hudng tdi chufc nang thi giac viec ren luyen de tang dung tieh t h d la can thiet vdi hpc vien va phi edng.
Liin quan gida mdc do ren luyen the thao, BMI vdi biin doi chdc ndng thl gidc
Chi sd BMI trong 2 nhdm la Bf^l 21,7 ± 2,0 va 20,9 + 2,1 deu trong gidi han blnh thudng, tuy nhien mdc dp ren luyen the thao anh hudng rd den sU bien ddi chdc nang thj giae. Trong nhdm ren luyen the thao thudng xuyen cd 69,4% doi tUpng cd bien ddi, trong khi nhdm khdng ren luyen sd ddi tUOng la 94,1%. Su khae biet nay cho thay vide ren luyen the thao thuc su can thiet dac biet cho nghe lai may bay.
Vdi phi cdng va hpc vien bay ren luyen the' thao thudng xuyen la mdt trong nhdng nhiem vu de dam b l o an toan bay theo quy djnh [3].
5. Ket luan
Nghien cdu cho thay trong dieu kien giam ap - thieu oxy tUOng dUOng dd eao 5000m cac chdc nang thj giac cd su suy giam theo thdi gian va khac nhau d cac ddi tupng: Bdi tUOng cd bien ddi chdc nang d thdi diem sau 5 phut cd 21 (39,6%), sau 15 phut cd 25 (47,2%), sau 25 phut ed 41 (77,4%). Ci phut t h d 25, thay ddi chdc nang quy t u , dieu tiet la 41 (77,4%), thj luc lap the 34 (64,2%), thi lUc nhin gan 31 (58,5%).
Cln d i i m quy t u xa mat hdn ban dau la 0,75 ± 0,6cm; bien dp didu tiet g i l m 0,96 ± 0,9D; thi lUc lap the g i l m 24,2 ± 2,6"; thi lUc nhin gan g i l m 1,1 ± 0,6 ddng. Cac ehde nang thi giae phue hdi hoan toan khi trd ve dieu kien binh thudng.
Su bien ddi chdc nang thj giac lien quan den thdi gian trong dieu kien giam ap - thieu oxy, he sd phoi va viec luyen tap the thao. Bien do suy giam chdc nang tang theo thdi gian. He sd phdi cua nhdm cd bien ddi la 58,5 ± 2,9, cda nhdm khdng bien doi chdc nang thj giae trong sudt 25 phut thieu oxy la 61,2 + 0,95. Trong nhdm ren luyen the thao thudng xuyen, ty le cd bien ddi la 69,4% ddi tupng, nhdm khdng ren luyen the thao thl 94,1 % ddi tUpng bien ddi.
Kie'm tra va luyen tap thudng xuyen de nang cao sUc chju dung trong dieu kien giam ap - thieu oxy la thue su can thiet vdi phi edng va hpc vien hpc Hi may bay, ddng gdp vao viec an toan bay.
Tai lieu t h a m khao
I. B6 Qude phong (2015) Diiu li Qidm dinh Y khoa khong qudn. Nha Xuat ban Quan dpi nhan dan.
2 Quan chung Khong quan (1993) Tiiu chudn khdm tuyen sdc khoi hgc viin Idi mdy bay qudn sU. Xudng in Khong quan.
3 Quach Van Mich va cpng sU (2004) Gido trinh Y hoc hdng khong. Quan chung Phong khong - Khong quan, Nha Xuat ban Quan dpi nhan dan.
4. Nguyen Van Tudng va Trjnh Binh Duy (2008) Sinh ly hdhap. Sinh ly hpc, Nha Xuat ban Y hpc, tr. 199-226.
5. Tran Van Xuan va Le Tien Hai (2010) Nghiin cdu sU biin ddi Idc an, thi gidc chiiu sdu cCia hgc viin bay vd phi cong qudn su bdng mdy Vision Tester trin budng gidm dp d do cao 5000m. Tap chi Y hpe Quan sU, chuyen de 1/2010.
6. Tdi lieu hudng ddn budng gidm dp A-HPO2016.
AUT-VAMED.
7 Doan P (2013) Sdc khde trin chuyen bay, vdn di thj gidc khi bay. Bao cao hpi nghi y hpc hang khong Pacific Angel.
8. FAA (2016) Guide for aviation medical examiners.
9. Kergoat H and Durand MJ (1996) Correlating increased ocular and systemic blood pressures with neuroretinai function. Aviat Space Environ Med 67(12): 1174-1178.
10. Kowalczuk KP et ai (2016) Hypoxia and coriolis illusion in pilots during simulated flight. Aerosp Med Hum Perform 87{2): 108-113.
I I . Thomas S (2013) Eye movement and binocular vision.
Chapters 10,14,26,27, Brien Holden Vision Institute.
