Acute Kidney Injury: Controversies Revisited

Table 4

Summary of studies of timing of initiating of RRT [24].

			RRT criteria		Survival (%)
Study	Size	Design	Early	Late	Early	Late	P value
Parsons et al. 1961 [83]	33	Retrospective	Urea 45–56	Urea > 75	75	12	N/A
Fischer et al. 1966 [84]	162	Retrospective	Urea ~ 56	Urea > 75	43	26	N/A
Kleinknecht et al. 1972 [85]	500	Retrospective	Urea < 35	Urea > 61	73	58	<.05
Conger et al. 1975 [86]	18	RCT	Urea < 26; or; Cr < 442	Urea ~ 56; or; Cr ~ 884; or; “clinically” indicated	64	20	NS
Gillum et al. 1986* [87]	34	RCT	Urea < 22.5; and; Cr < 442	Urea ~ 37.5; and; Cr ~ 795	41	53	NS
Gettings et al. 1989 [88]	100	Retrospective	Urea < 22.5	Urea > 22.5	39	20	N/A
Bouman** et al. 2002 [89]	106	RCT	<12 hrs after AKI diagnosis	Urea > 42; or; 𝐾>6.5; or; pulmonary oedema	69 (LV); 74 (HV)	75 (LV)	see Table 5
Demirkilic et al. 2004 [90]	61	Retrospective	Urine output < 100 mL/8hr	Cr > 442; or; 𝐾>5.5	77	45	0.016
Elahi et al. 2004 [91]	64	Retrospective	Urine output < 100 mL/8 hr	Urea ≥ 30; Or; Cr ≥ 250; Or; 𝐾>6	78	57	<.05
Piccinni et al. 2006 [92]	80	Retrospective	<12 hrs post-ICU admission	“conventional” indications	55	28	<.05
Liu et al. 2006 [93]	243	Prospective	Urea ≤ 28.5	Urea > 28.5	65	59	.09
Bagshaw*** et al. 2009 [94]	1238	Prospective	Urea ≤ 24.5; Or; Cr ≤ 309; Or; <2 days from ICU admission	Urea ≥ 24.5; Or; Cr ≥ 309; Or; >5 days from ICU admission	63.4 (urea); 53.4 (Cr); 59 (time)	61.4 (urea); 71.4 (Cr); 72.8 (time)	<.001 (stratified by days since ICU admission)

SI units for urea (mmol/L) and Cr (μmol/L) and K(mmol/L).
*Patients randomly assigned when serum Cr reached 707 μmol/L to maintain predialysis urea/Cr to early and late criteria as listed.
**Patients assigned to 3 treatment groups: early high volume (HV) CVVHDF, early low volume (LV) CVVHDF, and late low volume (LV) CVVHDF.
***Early and late RRT assessed separately by urea, Cr and time in ICU criteria.