Early-phase cumulative hypotension duration and severe-stage progression in oliguric acute kidney injury with and without sepsis: an observational study.

Junichi Izawa,Masanori Takinami,Taku Iwami,Takashi Kawamura,Shigehiko Uchino,Tetsuhisa Kitamura,John A Kellum

doi:10.1186/s13054-016-1564-2

Abstract

BackgroundManaging blood pressure in patients with acute kidney injury (AKI) could effectively prevent severe-stage progression. However, the effect of hypotension duration in the early phase of AKI remains poorly understood. This study investigated the association between early-phase cumulative duration of hypotension below threshold mean arterial pressure (MAP) and severe-stage progression of oliguric AKI in critically ill patients, and assessed the difference in association with presence of sepsis.MethodsThis was a single-center, observational study conducted in the ICU of a university hospital in Japan. We examined data from adults with oliguric AKI who were admitted to the ICU during 2010–2014 and stayed in the ICU for ≥24 h after diagnosis of stage-1 oliguric AKI defined in the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. The primary outcome was the progression from stage-1 oliguric AKI to stage-3 oliguric AKI (progression to oligoanuria and use of renal replacement therapy) according to the KDIGO criteria. During the first 6 h after oliguric AKI, we analyzed the association between cumulative time the patient had below threshold MAP (65, 70, and 75 mm Hg) and progression to stage-3.ResultsAmong 538 patients with oliguric AKI, progression to stage-3 increased as the time spent below any threshold MAP was elongated. In the multivariable analysis of all patients, longer hypotension time (3–6 h) showed significant association with stage-3 progression for the time spent below MAP of 65 mm Hg (adjusted odds ratio (OR) 3.73, 95% confidence interval (CI) 1.53–9.09, p = 0.004), but the association was attenuated for the threshold MAP of 70 mm Hg (adjusted OR 2.35, 95% CI 0.96–5.78, p = 0.063) and 75 mm Hg (adjusted OR 1.92, 95% CI 0.72–5.15, p = 0.200). Longer hypotension time with the thresholds of 65 and 70 mm Hg was significantly associated with the risk of stage-3 progression in patients without sepsis, whereas the association was weak and not significant in patients with sepsis.ConclusionsEven in a short time frame (6 h) after oliguric AKI diagnosis, early-phase cumulative hypotension duration was associated with progression to stage-3 oliguric AKI, especially in patients without sepsis.

Highlights

Managing blood pressure in patients with acute kidney injury (AKI) could effectively prevent severestage progression
We examined data from consecutive patients aged ≥18 years who had not undergone maintenance dialysis and who stayed in the intensive care unit (ICU) for at least 24 h after the diagnosis of oliguric AKI, which was defined as stage-1 oliguric AKI, urine output
We extracted 807 patients who stayed in the ICU for ≥24 h after oliguric AKI diagnosis

Summary

Introduction

Managing blood pressure in patients with acute kidney injury (AKI) could effectively prevent severestage progression. The effect of hypotension duration in the early phase of AKI remains poorly understood. This study investigated the association between early-phase cumulative duration of hypotension below threshold mean arterial pressure (MAP) and severe-stage progression of oliguric AKI in critically ill patients, and assessed the difference in association with presence of sepsis. When critical illness is complicated by AKI, there is a well-known association with increased mortality [1, 2], but preventive measures have not yet been established. Maintenance of normal or even increased mean arterial pressure (MAP) could provide a benefit because autoregulation of blood flow is known to be lost during certain forms of AKI, especially in patients with sepsis [3]. Some studies have failed to indicate the effectiveness of maintaining high MAP in AKI management [10, 11]

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