title: Early-phase cumulative hypotension duration and severe-stage progression in oliguric acute kidney injury with and without sepsis: an observational study.
abstract: BACKGROUND
  Managing 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.
  
  
  METHODS
  This 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.
  
  
  RESULTS
  Among 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.
  
  
  CONCLUSIONS
  Even 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.
authors.affiliation: Department of Preventive Services, Kyoto University School of Public Health, Yoshida-Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.|Intensive Care Unit, Department of Anesthesiology, The Jikei University School of Medicine, 3-19-18 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8471, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Izawa
authors.affiliation: Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, 1-1 Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Tetsuhisa
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Preventive Services, Kyoto University School of Public Health, Yoshida-Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan. iwami.taku.8w@kyoto-u.ac.jp.
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
authors.affiliation: Intensive Care Unit, Department of Anesthesiology, The Jikei University School of Medicine, 3-19-18 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8471, Japan.
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Uchino
authors.affiliation: Intensive Care Unit, Department of Anesthesiology, The Jikei University School of Medicine, 3-19-18 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8471, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Takinami
authors.affiliation: Center for Critical Care Nephrology, University of Pittsburgh Medical Center, 604 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, 15261, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Kellum
authors.affiliation: Department of Preventive Services, Kyoto University School of Public Health, Yoshida-Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawamura
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000503:physiopathology; D000368:Aged; D062186:Arterial Pressure / Q000502:physiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications*; D007362:Intensive Care Units / Q000458:organization & administration / Q000706:statistics & numerical data; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009846:Oliguria / Q000503:physiopathology; D063868:Patient Outcome Assessment; D018805:Sepsis / Q000150:complications / Q000503:physiopathology; D018709:Statistics, Nonparametric; D013997:Time Factors; D014882:Water-Electrolyte Balance / Q000502:physiology
keywords: Acute kidney injury; Arterial pressure; Critical illness; Epidemiology; Hypotension; Intensive care unit