Increased Fluid Administration After Early Acute Kidney Injury is Associated with Less Renal Recovery.
BACKGROUND
In acute kidney injury (AKI), fluid accumulation is associated with poor outcome. We aimed to determine whether fluid intake or output had the major role.


METHODS
Retrospective analysis of patients admitted to the Intensive Care Unit between July 2007 and June 2009 who had AKI stage I. We collected fluid input, output, and haemodynamic data on day of AKI I and on day of AKI III (if AKI III developed) or 72  h after AKI I (if patients did not progress to AKI III). Univariable and multivariable logistic regression analyses were performed.


RESULTS
Among 210 patients with AKI I (median age 70 y; 138 males), 85 had a subsequent mean fluid gain >1 L/day. Their risk of AKI III or death in intensive care unit was significantly higher compared with patients who gained ≤1 L/day (63.5% vs. 23.3%, P = 0.001, and 43.5% vs. 24.8%, P = 0.004, respectively). AKI I patients who gained >1 L/day had a significantly lower urine output (50 vs. 66  mL/h, P = 0.02), lower mean arterial pressure (71 vs. 74  mmHg, P = 0.01), higher arterial lactate level (2.7 vs. 2.0  mmol/L, P < 0.001), and higher Sequential Organ Failure Assessment score (9.4 vs. 8.2, P = 0.002) on day of AKI I compared with those who gained ≤ 1 L/day. Multivariable analysis showed that only fluid intake was independently associated with progression to AKI III (OR 1.8 per 1 L; 95% CI 1.1 - 8.8; P = 0.02), but reduced urine output was not an independent risk factor (OR 0.8; 95% CI 0.3 - 2.2; P = 0.6).


CONCLUSIONS
Increased fluid intake in early AKI was an independent risk factor for AKI III.
*Department of Critical Care, Guy's & St Thomas' Foundation Hospital, London, UK †Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal ‡Division of Health and Social Care Research, NIHR Biomedical Research Centre, King's College London, London §John Farman Intensive Care Unit, Addenbrooke's Hospital, Cambridge ¶King's College London, London, UK.
Mario
M
Raimundo
Siobhan
S
Crichton
John R
JR
Martin
Yadullah
Y
Syed
Matt
M
Varrier
Duncan
D
Wyncoll
Marlies
M
Ostermann
D058186:Acute Kidney Injury / Q000503:physiopathology / Q000628:therapy*; D000368:Aged; D018450:Disease Progression; D005260:Female; D005440:Fluid Therapy / Q000009:adverse effects* / Q000379:methods; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014554:Urination / Q000502:physiology