Acute kidney injury patterns and outcomes in low-risk versus high-risk critically ill patients admitted to the medical intensive care unit

Cyriacus U Anaele MD, Gabriela Suarez MD, Sofia Kennedy-Prieto MD, Mamoun Bashir MD, Melvin Laski MD, Shengping Yang PhD

ABSTRACT

Background: Acute kidney injury (AKI) is often one component of multiple organ failure (MOF) in the intensive care unit (ICU). However, not all patients with MOF develop AKI, and AKI may develop in the absence of MOF. We compared the impact of AKI alone and in combination with MOF on the survival of patients admitted to a large tertiary care medical intensive care unit (MICU).

Methods: We abstracted data from the electronic medical records of patients admitted to the MICU from April 2012 through June 2013 and categorized patients as either high-risk or low-risk status based on use of vasopressor support or mechanical ventilation during the ICU stay. The outcomes we considered were in-hospital, 30 day, 90 day, 180 day, and 1 year mortality.

Results: Of the 834 critically ill patients, 743 (89%) developed some degree of AKI. Ninety-one percent of the high-risk cohort developed AKI and 87% of the low-risk cohort developed AKI. Patients with AKI had higher mortality at 1 year than patients without AKI (adjusted odds ratio [OR], 2.5; 95% confidence interval, 1.38 to 4.53); P interaction 0.003). Hospital mortality was greater for high-risk patients without AKI than for low-risk patients with AKI.

Conclusion: Acute kidney injury occurs at similar frequency in high- and low-risk ICU patients and has significant impact on survival in both groups. Cardiovascular collapse or respiratory failure has greater impact on short term mortality than AKI, but this effect diminishes over time. Conversely, the impact of AKI on mortality increased over time and remained an independent risk factor for mortality.

Keywords: Acute kidney injury, intensive care unit, critically ill patients, mortality, length of stay

Article citation: Anaele CU, Suarez G, Kennedy-Prieto S, Bashir M, Laski M, Yang S. Acute kidney injury patterns and outcomes in low-risk versus high-risk critically ill patients admitted to the medical intensive care unit. The Southwest Respiratory and Critical Care Chronicles 2017;5(17):17-31.
DOI: 10.12746/swrccc2017.0517.237
From: Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX.
Corresponding author: Cyriacus U Anaele at anaeluzo@yahoo.com