Targeting urine output and 30-day mortality in goal-directed therapy: a systematic review with meta-analysis and meta-regression

Abstract

BackgroundOliguria is associated with a decreased kidney- and organ perfusion, leading to organ damage and increased mortality. While the effects of correcting oliguria on renal outcome have been investigated frequently, whether urine output is a modifiable risk factor for mortality or simply an epiphenomenon remains unclear. We investigated whether targeting urine output, defined as achieving and maintaining urine output above a predefined threshold, in hemodynamic management protocols affects 30-day mortality in perioperative and critical care.MethodsWe performed a systematic review with a random-effects meta-analyses and meta-regression based on search strategy through MEDLINE, EMBASE and references in relevant articles. We included studies comparing conventional fluid management with goal-directed therapy and reporting whether urine output was used as target or not, and reporting 30-day mortality data in perioperative and critical care.ResultsWe found 36 studies in which goal-directed therapy reduced 30-day mortality (OR 0.825; 95% CI 0.684-0.995; P = 0.045). Targeting urine output within goal-directed therapy increased 30-day mortality (OR 2.66; 95% CI 1.06-6.67; P = 0.037), but not in conventional fluid management (OR 1.77; 95% CI 0.59-5.34; P = 0.305). After adjusting for operative setting, hemodynamic monitoring device, underlying etiology, use of vasoactive medication and year of publication, we found insufficient evidence to associate targeting urine output with a change in 30-day mortality (goal-directed therapy: OR 1.17; 95% CI 0.54-2.56; P = 0.685; conventional fluid management: OR 0.74; 95% CI 0.39-1.38; P = 0.334).ConclusionsThe principal finding of this meta-analysis is that after adjusting for confounders, there is insufficient evidence to associate targeting urine output with an effect on 30-day mortality. The paucity of direct data illustrates the need for further research on whether permissive oliguria should be a key component of fluid management protocols.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-017-0316-4) contains supplementary material, which is available to authorized users.

Intraoperative permissive oliguria – how much is too much?

“…A recent metaanalysis including 36 randomized controlled trials in perioperative medicine and critical care demonstrated that targeting urine output does not affect 30-day mortality, suggesting that oliguria is not a modifiable risk factor for mortality. 36 On the other hand, accepting a low urine output caused by hypovolaemia including the associated haemodynamic effects might result in reduced kidney perfusion and kidney injury. The study by Mizota and colleagues in this issue of the BJA suggests that oliguria with a threshold of < 0.3 ml kg À1 h À1 might be an appropriate early intraoperative indicator of AKI.…”

Methodology in systematic reviews of goal-directed therapy: improving but not perfect

“…Over the years, the quality of systematic reviews conducted in the field of anaesthesia has improved, 22 and in this issue of the British Journal of Anaesthesia, Michard and colleagues 23 provide a thoroughly prepared meta-analysis of the clinical impact of perioperative goal-directed therapy when uncalibrated pulse-contour cardiac output monitors are used to titrate treatment. In line with most systematic reviews on goal-directed therapy, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Michard and colleagues 23 conclude that goal-directed therapy reduces postoperative complications. In addition, they showed that total fluid volumes were not different between experimental and control groups, although giving fluid is an intervention.…”

“…This has been followed by a wave of systematic reviews, in particular over the last five years, trying to summarize and derive conclusions and recommendations from many of these studies. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Terminology for systematic reviews and meta-analyses is frequently used incorrectly. A systematic review refers to a rigorous scientific process of reviewing relevant literature whereas meta-analysis refers to a statistical method of pooling data from multiple studies to derive a summary effect estimate.…”

Goal‐directed fluid therapy during major abdominal surgery

“…22 [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] 24 23 k 121 (10 -3 min -1 ) 236 In the whole cohort of Studies I-III, no correlation was found between preoperative dehydration as quantified by the dehydration index, and presumed preoperative hypovolemia as quantified by the volume of colloid needed during induction and the first optimisation round (Fig 15).…”