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Optimal provtid (Jacobsson)

Kalkylator

Optimal tidpunkt för plasmaprovet vid Jacobssons enpunktsmetod — från skattad extracellulärvolym och GFR.

Optimal provtid—tim:min efter injektion
Patient & GFR
kg
cm
mL/min
eECV-formel
Härlett
Beräknat eECV—L
Optimal provtid—tim:min

Estimerat GFR kan hämtas från t.ex. eGFR- eller iohexolverktyget. Metod, formel och referenser finns nedan.
Referenser

Metod och eECV-formler

  • [1] Jacobsson L. (1983). A method for the calculation of renal clearance based on a single plasma sample. Clinical Physiology, 3(4), 297–305. DOI ↗
  • [2] Granerus G, Jacobsson L. (1985). Beräkning av 51Cr-EDTA single injection clearance – jämförelse mellan flerpunkts- och enpunktsformel. Svensk förening för medicinsk radiologi, Förhandlingar, 19, 71–73.
  • [3] Stake G, Monclair T. (1991). A single plasma sample method for estimation of the GFR in infants and children using iohexol. I: Establishment of a body weight-related formula for the distribution volume of iohexol. Scandinavian Journal of Clinical and Laboratory Investigation, 51(4), 335–342. PMID: 1947718. DOI ↗
  • [4] Bird NJ, Henderson BL, Lui D, Ballinger JR, Peters AM. (2003). Indexing glomerular filtration rate to suit children. Journal of Nuclear Medicine, 44(7), 1037–1043. PMID: 12843217. PubMed ↗
  • [5] Bird NJ, Peters AM. (2021). New gender-specific formulae for estimating extracellular fluid volume from height and weight in adults. Nuclear Medicine Communications, 42(1), 58–62. DOI ↗
  • [6] Watson WS. (1992). A simple method of estimating glomerular filtration rate. European Journal of Nuclear Medicine, 19, 827. (Letter to the editor). DOI ↗
  • [7] Peters AM. (2011). Re-evaluation of the new Jødal–Brøchner-Mortensen equation for one-pool correction of slope-intercept measurement of GFR. Nuclear Medicine Communications, 32(5), 375–380. PMID: 21301378. DOI ↗

Kroppsyta (BSA)

  • [8] Du Bois D, Du Bois EF. (1916). A formula to estimate the approximate surface area if height and weight be known. Archives of Internal Medicine, 17(6_2), 863–871. DOI ↗
  • [9] Haycock GB, Schwartz GJ, Wisotsky DH. (1978). Geometric method for measuring body surface area: A height-weight formula validated in infants, children, and adults. The Journal of Pediatrics, 93(1), 62–66. DOI ↗
Metodik och formler
Optimal provtid

Den optimala provtagningstiden för Jacobssons enpunktsmetod är medeluppehållstiden för spårämnet — skattad extracellulärvolym (eECV) dividerad med absolut clearance (GFR):

topt=eECVGFRt_{opt}=\frac{eECV}{GFR}
[1]

eECV i mL och GFR i mL/min ger topt i minuter (visas som tim:min).

eECV-formler

Vikt W i kg, längd H i cm.

eECVGranerus&Jacobsson={166W+2490,man95W+6170,kvinnaeECV_{Granerus\&Jacobsson}=\begin{cases}166W+2490, & \text{man}\\ 95W+6170, & \text{kvinna}\end{cases}
[2]
eECVJacobsson=246WeECV_{Jacobsson}=246W
[1]
eECVStake=231W+1215eECV_{Stake}=231W+1215
[3]
eECVBird 2003=1000(0.02154 W0.6469H0.7236)eECV_{Bird\,2003}=1000\left(0.02154\,W^{0.6469}H^{0.7236}\right)
[4]
eECVBird&Peters={1000(0.0755 W0.6185H0.4982),man1000(0.0399 W0.6065H0.6217),kvinnaeECV_{Bird\&Peters}=\begin{cases}1000\left(0.0755\,W^{0.6185}H^{0.4982}\right), & \text{man}\\ 1000\left(0.0399\,W^{0.6065}H^{0.6217}\right), & \text{kvinna}\end{cases}
[5]
eECVDuBois/Watson=8116.6⋅BSADu Bois−28.2eECV_{DuBois/Watson}=8116.6\cdot BSA_{Du\,Bois}-28.2
[6, 8]
eECVBSA6080=6080⋅BSAHaycock1.34eECV_{BSA6080}=6080\cdot BSA_{Haycock}^{1.34}
[7, 9]
Kroppsyta (BSA)

Används av eECV-formlerna Du Bois/Watson respektive BSA-baserad.

BSADu Bois=0.007184 W0.425H0.725BSA_{Du\,Bois}=0.007184\,W^{0.425}H^{0.725}
[8]
BSAHaycock=0.024265 W0.5378H0.3964BSA_{Haycock}=0.024265\,W^{0.5378}H^{0.3964}
[9]