Assessing Glomerular Filtration Rate in Hospitalized Patients

Abstract

SummaryBackground and objectives A specific method is required for estimating glomerular filtration rate GFR in hospitalized patients. Our objective was to validate the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and four cystatin C (CysC)-based equations in this setting.Design, setting, participants, & measurements This was an epidemiologic, cross-sectional study in a random sample of hospitalized patients (n ϭ 3114). We studied the accuracy of the CKD-EPI and four CysC-based equations-based on (1) CysC alone or (2) adjusted by gender; (3) age, gender, and race; and (4) age, gender, race, and creatinine, respectively-compared with GFR measured by iohexol clearance (mGFR). Clinical, biochemical, and nutritional data were also collected.Results The CysC equation 3 significantly overestimated the GFR (bias of 7.4 ml/min per 1.73 m 2 ). Most of the error in creatinine-based equations was attributable to calculated muscle mass, which depended on patient's nutritional status. In patients without malnutrition or reduced body surface area, the CKD-EPI equation adequately estimated GFR. Equations based on CysC gave more precise mGFR estimates when malnutrition, extensive reduction of body surface area, or loss of muscle mass were present (biases of 1 and 1.3 ml/min per 1.73 m 2 for equations 2 and 4, respectively, versus 5.9 ml/min per 1.73 m 2 for CKD-EPI). ConclusionsThese results suggest that the use of equations based on CysC and gender, or CysC, age, gender, and race, is more appropriate in hospitalized patients to estimate GFR, since these equations are much less dependent on patient's nutritional status or muscle mass than the CKD-EPI equation.

Two Novel Equations to Estimate Kidney Function in Persons Aged 70 Years or Older

“…Data in the literature support the notion that plasma clearance has the potential for higher precision than urinary clearance (46,47). We only found 1 other study that measured iohexol clearance in a large sample of elderly patients (48). However, this study investigates hospitalized patients only and differs considerably in terms of methodology of clearance measurements.…”

Exploration de la fonction glomérulaire rénale : estimation du débit de filtration glomérulaire

“…Gerhardt [96]. Cela illustre, une fois de plus, les mauvaises performances des estimateurs chez des patients à é tat gé né ral trè s alté ré [38,97].…”

“…Cependant, il n'en reste pas moins que la variabilité de la cystatine C expliqué e par la masse musculaire est bien moindre que pour la cré atinine. L'avantage de la cystatine C sur la cré atinine chez le patient avec une masse musculaire diminué e reste donc important [97,112].…”

“…L'avantage de ces formules apparaît, aujourd'hui, relativement faible par rapport à la formule MDRD basé e sur la cré atininé mie, l'âge, le sexe et la race, en tout cas en ce qui concerne la population gé né rale. Toutefois, elles pourraient être plus utiles dans certaines sous-populations où les formules basé es sur la cré atinine se sont ré vé lé es particuliè rement peu exactes, comme en pé diatrie [41,134,135,138], en transplantation [41,84,134,135,140], en gé riatrie ou chez le patient dé nutri [97,112].…”

Comparison of seven estimated glomerular filtration rate equations in kidney patients

“…Megállapításuk szerint a cisztatin-C-s képletük használható volt a kreatininalapú helyett, amikor az nem volt alkalmazható (malnutritio, erősen csökkent testfelület, izomtömeg-csökkenés). Ezt támasztotta alá egy hospitalizált betegeken végzett tanulmány is [38].…”