Umlinganiselo wokuhamba kwegazi wawusetyenziselwa ukuba ngumsebenzi we-crappy kumbala we-Doppler ultrasound.Ngoku, ngokuqhubekayo ukuthandwa kwe-ultrasound kwintsimi ye-hemodialysis vascular access, ibe yimfuno enzima ngakumbi.Nangona kuxhaphake kakhulu ukusebenzisa i-ultrasound ukulinganisa ukuhamba kolwelo kwimibhobho yemizi-mveliso, ayizange inikwe ingqwalasela enkulu kumlinganiselo wokuhamba kwegazi kwimithambo yegazi emzimbeni womntu.Kukho isizathu soko.Xa kuthelekiswa nemibhobho yemizi-mveliso, imithambo yegazi emzimbeni womntu ingcwatywa phantsi kwesikhumba esingabonakaliyo, kwaye ububanzi betyhubhu buhluka kakhulu (umzekelo, ububanzi bezinye iinqanawa phambi kwe-AVF bungaphantsi kwe-2mm, kwaye ezinye ii-AVF zingaphezulu. ngaphezu kwe-5mm emva kokuvuthwa), kwaye ngokubanzi zinwebeka, nto leyo izisa ukungaqiniseki okukhulu kumlinganiselo wokuqukuqela.Eli phepha lenza uhlalutyo olulula lwezinto ezichaphazelayo zokulinganisa ukuhamba, kwaye likhokela imisebenzi ebonakalayo evela kule miba, ngaloo ndlela iphucula ukuchaneka nokuphindaphinda kokulinganisa ukuhamba kwegazi.
Ifomula yoqikelelo lokuhamba kwegazi:
Ukuhamba kwegazi = umyinge wexesha lokuhamba kwexesha × indawo enqamlezileyo × 60, (iyunithi: ml / min)
Ifomula ilula kakhulu.Ngumthamo nje wolwelo oluqukuqela kwindawo enqamlezileyo yomthambo wegazi ngexesha leyunithi nganye.Into ekufuneka iqikelelwe zezi ziguquguqukayo zimbini-- indawo enqamlezileyo kunye nomyinge wokuhamba komndilili.
Ummandla we-cross-sectional kwi-formula engentla isekelwe ekucingeni ukuba isitya segazi sisityhubhu esiqinileyo setyhubhu, kunye nommandla we-cross-sectional = 1/4 * π * d * d, apho i-d yi-diameter ye-diameter yegazi. .Nangona kunjalo, imithambo yegazi yomntu yokwenyani i-elastic, ekulula ukuyicinezela kunye nokukhubazeka (ingakumbi imithambo).Ngoko ke, xa ulinganisa ububanzi bombhobho okanye ukulinganisa izinga lokuhamba, kufuneka uqinisekise ukuba imithwalo yegazi ayigxininisi okanye ikhubazekile njengoko unako.Xa siskena icandelo le-longitudinal, amandla angenziwa ngokungazi kwiimeko ezininzi, ngoko kuyacetyiswa ngokubanzi ukugqiba umlinganiselo wedayamitha yombhobho kwicandelo lomnqamlezo.Kwimeko apho inqwelomoya enqamlezileyo ayiculwanga ngamandla angaphandle, umthambo wegazi ngokuqhelekileyo isangqa esiqikelelweyo, kodwa kwimeko ecinezelweyo, idla ngokuba yi-ellipse ethe tyaba.Sinokulinganisa i-diameter yomkhumbi kwimeko yendalo, kwaye sifumane ixabiso eliqhelekileyo lokulinganisa i-diameter njengereferensi yemilinganiselo yecandelo le-longitudinal elandelayo.
Ngaphandle kokuphepha ukucudisa imithambo yegazi, kuyafuneka ukuba ubeke ingqalelo ekwenzeni imithambo yegazi ihambelane necandelo lomfanekiso we-ultrasound xa ulinganisa icandelo lomnqamlezo wemithambo yegazi.Indlela yokugweba ukuba imithambo yegazi ithe nkqo kuba iphantsi kwesikhumba?Ukuba icandelo lokucinga le-probe alikho kwi-perpendicular to the blood (kwaye isitya segazi asiculwanga), umfanekiso ofunyenweyo we-cross-sectional nawo uya kuba yi-ellipse emile, eyahlukileyo kwi-ellipse ethe tye eyenziwe yi-extrusion.Xa i-angle ye-tilt ye-probe inkulu, i-ellipse ibonakala ngakumbi.Ngexesha elifanayo, ngenxa ye-tilt, amandla amaninzi esiganeko se-ultrasound sibonakaliswa kwezinye izikhokelo, kwaye kuphela i-echoes encinci efunyenwe yi-probe, ebangela ukuba ukukhanya komfanekiso kunciphe.Ngoko ke, ukugweba ukuba i-probe i-perpendicular kumkhumbi wegazi ngokusebenzisa i-engile ukuba umfanekiso oqaqambileyo nayo yindlela efanelekileyo.
Ngokuphepha ukuphazamiseka kwenqanawa kunye nokugcina i-probe perpendicular kwinqanawa kangangoko kunokwenzeka, umlinganiselo ochanekileyo we-diameter yesitya kwi-cross-section inokufezekiswa ngokulula ngokusebenza.Nangona kunjalo, kuya kuhlala kukho umahluko kwiziphumo zomlinganiselo ngamnye.Kunokwenzeka ukuba umkhumbi awukho ityhubhu yensimbi, kwaye iya kwandisa okanye inkontileka kunye neenguqu kwixinzelelo lwegazi ngexesha lomjikelezo wenhliziyo.Umfanekiso ongezantsi ubonisa iziphumo ze-carotid pulses kwi-B-mode ultrasound kunye ne-M-mode ultrasound.Umahluko phakathi kwe-systolic kunye ne-diastolic diastolic ezilinganiswe kwi-M-ultrasound ingaba malunga ne-10%, kwaye umehluko we-10% ububanzi unokubangela ukuba umehluko we-20% kwindawo ye-cross-sectional.Ukufikelela kwi-hemodialysis kufuna ukuhamba okuphezulu kwaye i-pulsation yemikhumbi ibonakala ngakumbi kunesiqhelo.Ke ngoko, impazamo yokulinganisa okanye ukuphindaphindwa kwale nxalenye yomlinganiselo inokunyamezela kuphela.Akukho ngcebiso ilungileyo, ke thatha nje imilinganiselo embalwa xa unexesha kwaye ukhethe umndilili.
Ekubeni ukulungelelaniswa okuthe ngqo kwenqanawa okanye i-angle enecandelo le-probe ayinakukwaziwa phantsi kwe-transverse view, kodwa kwi-longitudinal view yesitya, ukulungelelaniswa komkhumbi kunokubonwa kunye ne-angle phakathi kolwalathiso lwenqanawa kunye nokulungelelaniswa. umgca wokuskena weDoppler unokulinganiswa.Ngoko ke uqikelelo lwesantya sokuhamba kwegazi kwinqanawa lunokwenziwa kuphela phantsi kokutshayela i-longitudinal.Ukutshayela inqanawa ixesha elide ngumsebenzi onzima kuninzi lwabaqalayo.Kanye njengaxa umpheki esika imifuno eyicolumnari, imela idla ngokusikwa kwinqwelomoya, ukuba awundikholelwa, zama ukusika iasparagus kwinqwelomoya yobude.Xa usika i-asparagus ixesha elide, ukwahlula i-asparagus ibe ngamacandelo amabini alinganayo, kuyimfuneko ukubeka imela ngokucophelela phezulu, kodwa nokuqinisekisa ukuba indiza yemela inokuwela nje i-axis, ngaphandle koko imela iya kuba nzima. iasparagus kufuneka iqengqeleke ecaleni.
Kukwanjalo nangokutshayela i-longitudinal ultrasound yenqanawa.Ukulinganisa i-diameter ye-longitudinal isitya, icandelo le-ultrasound kufuneka lidlule kwi-axis yomkhumbi, kwaye kuphela emva koko isiganeko se-ultrasound sixhomekeke kwiindonga zangaphambili kunye nezingasemva zomkhumbi.Logama nje i-probe ibekwe ecaleni kancinci, ezinye zezehlo ze-ultrasound ziya kubonakaliswa kwezinye izikhokelo, okukhokelela kubuthathaka obufunyenwe yi-probe, kwaye kudityaniswa nenyaniso yokuba izilayi ze-ultrasound ze-beam (i-acoustic lens focus) inobukhulu, kukho into ebizwa ngokuba yi "partial volume effect", evumela ukuba i-echoes ezivela kwiindawo ezahlukeneyo kunye nobunzulu bodonga lwesitya zidibaniswe kunye, okubangela ukuba Umfanekiso ube mnyama kwaye udonga lwetyhubhu alubonakali lugudileyo.Ngoko ke, ngokuqwalasela umfanekiso wecandelo le-longitudinal eskeniweyo kwinqanawa, sinokugqiba ukuba icandelo le-longitudinal eskeniweyo lifanelekile ngokuqwalasela ukuba udonga lugudile, lucacile kwaye lukhanyayo.Ukuba i-artery is scanned, i-intima inokubonwa ngokucacileyo kwindawo efanelekileyo yokujonga i-longitudinal.Emva kokufumana umfanekiso ofanelekileyo we-2D we-longitudinal, umlinganiselo wedayamitha uchanekile, kwaye kuyafuneka kumfanekiso wokuhamba kwe-Doppler olandelayo.
I-Doppler flow imaging yahlulahlulwe ngokubanzi ibe yi-two-dimensional color flow imaging kunye ne-pulsed wave wave Doppler (PWD) imaging ebukekayo enendawo yesango yesampulu esisigxina.Singasebenzisa umfanekiso wokuhamba kombala ukwenza ukutshatyalaliswa kwe-longitudinal eqhubekayo ukusuka kwi-artery ukuya kwi-anastomosis kwaye emva koko ukusuka kwi-anastomosis ukuya kwi-vein, kwaye imephu yesantya yokuhamba kombala inokuchonga ngokukhawuleza amacandelo angaqhelekanga e-vascular njenge-stenosis kunye ne-occlusion.Nangona kunjalo, kumlinganiselo wokuhamba kwegazi, kubalulekile ukunqanda indawo yala macandelo eenqanawa ezingaqhelekanga, ngakumbi i-anastomoses kunye ne-stenoses, okuthetha ukuba indawo efanelekileyo yokulinganisa ukuhamba kwegazi licandelo lesitya esithe tyaba.Oku kungenxa yokuba kuphela kumacandelo amade ngokwaneleyo anokuthi ukuhamba kwegazi kuthande ukuhamba okuzinzileyo kwe-laminar, ngelixa kwiindawo ezingaqhelekanga ezifana ne-stenoses okanye i-aneurysms, isimo sokuhamba sinokutshintsha ngokukhawuleza, kubangele ukuhamba kwe-eddi okanye ukuphazamiseka.Kumzobo wokuhamba kombala we-carotid artery eqhelekileyo kunye ne-stenotic carotid artery eboniswe ngezantsi, ukuhamba kwi-laminar state kubonakaliswe ngesantya esiphezulu sokuhamba phakathi kwenqanawa kunye nokunciphisa ukuhamba kwesantya kufuphi nodonga, ngelixa kwicandelo le-stenotic ( ngakumbi ezantsi kwe-stenosis), imeko yokuqukuqela ayiqhelekanga kwaye indlela yokuhamba kweeseli zegazi ayilungelelaniswa, nto leyo ekhokelela ekungalungelelaniseni okubomvu-blue kumfanekiso wokuqukuqela kombala.
Ixesha lokuposa: Feb-07-2022
