Izindaba

UMLANDO NOKUZIQHUMA KWE-ANASTHESIA ENGAPHAKATHI KWEMITHAMBO

Ukuphathwa kwemithi nge-intravenous kusukela ekhulwini le-17 lapho uChristopher Wren efaka i-opium enjeni esebenzisa i-goose quill kanye nesinye sengulube futhi inja 'yaphambuka'. Ngawo-1930 i-hexobarbital kanye ne-pentothal kwafakwa emtholampilo.

Kwakuyi-Pharmacokinetic yama-1960 lapho kwakhiwa khona amamodeli kanye nezilinganiso zokufakwa kwe-IV kanti ngawo-1980, kwafakwa izinhlelo zokufakwa kwe-IV ezilawulwa yikhompyutha. Ngo-1996 kwafakwa uhlelo lokuqala lokufakwa kwe-target controlled infusion ('Diprufusor').

INCAZELO

A ukumnika okulawulwa okuqondiwekuwukufakwa komuthi okulawulwa ngendlela yokuthi kuzanywe ukufeza ukuhlushwa kwesidakamizwa okuchazwe ngumsebenzisi engxenyeni yomzimba enesithakazelo noma izicubu ezithandekayo. Lo mqondo waphakanyiswa okokuqala nguKruger Thiemer ngo-1968.

IMITHI

Umthamo wokusatshalaliswa.

Lona umthamo obonakalayo lapho umuthi usatshalaliswa khona. Ubalwa ngefomula: Vd = umthamo/ukuhlushwa komuthi. Inani lawo lincike ekutheni libalwa ngesikhathi esingu-zero – ngemva kwe-bolus (Vc) noma esimweni esizinzile ngemva kokumnika (Vss).

Ukususwa kwempahla.

I-Clearance imele ivolumu ye-plasma (Vp) lapho umuthi ukhishwa khona ngeyunithi ngayinye isikhathi ukuze kubhekwe ukukhishwa kwawo emzimbeni. I-Clearance = Ukususwa X Vp.

Njengoba ukuhlukaniswa kwanda, isigamu sokuphila siyancipha, futhi njengoba ivolumu yokusatshalaliswa ikhuphuka, nesigamu sokuphila siyanda. Ukuhlukaniswa kungasetshenziswa futhi ukuchaza ukuthi umuthi uhamba ngokushesha kangakanani phakathi kwezingxenye. Umuthi uqala ukusatshalaliswa endaweni ephakathi ngaphambi kokusatshalaliswa ezindaweni ezingaphandle. Uma ivolumu yokuqala yokusatshalaliswa (Vc) kanye nokuhlushwa okufiselekayo komphumela wokwelapha (Cp) kwaziwa, kungenzeka ukubala umthamo wokulayisha ukuze kufezwe lokho kuhlushwa:

Umthamo wokulayisha = Cp x Vc

Ingasetshenziswa futhi ukubala umthamo we-bolus odingekayo ukuze kwandiswe ngokushesha ukuhlushwa ngesikhathi sokufakwa okuqhubekayo: Umthamo we-Bolus = (Cnew - Cactual) X Vc. Izinga lokufakwa ukuze kugcinwe isimo esizinzile = Cp X Clearance.

Izindlela ezilula zokufaka umuthi azifinyeleli izinga elizinzile le-plasma kuze kube okungenani izikhathi ezinhlanu zokukhishwa kwesigamu sokuphila. Izinga elifunekayo lingatholakala ngokushesha uma umthamo we-bolus ulandelwa izinga lokufakwa.