Outcome of critically ill patients with acute kidney injury using the Acute Kidney Injury Network criteria.

Crit Care Med. 2011 Dec;39(12):2659-64

Authors: Mandelbaum T, Scott DJ, Lee J, Mark RG, Malhotra A, Waikar SS, Howell MD, Talmor D

Abstract
OBJECTIVE: Acute kidney injury affects 5% to 7% of all hospitalized patients with a much higher incidence in the critically ill. The Acute Kidney Injury Network proposed a definition in which serum creatinine rises (>0.3 mg/dL) and/or oliguria (<0.5 mL/kg/hr) for a period of 6 hrs are used to detect acute kidney injury. Accurate urine output measurements as well as serum creatinine values from our database were used to detect patients with acute kidney injury and calculate their corresponding mortality risk and length of stay.
DESIGN: Retrospective cohort study.
SETTING: Seven intensive care units at a large, academic, tertiary medical center.
PATIENTS: Adult patients without evidence of end-stage renal disease with more than two creatinine measurements and at least a 6-hr urine output recording who were admitted to the intensive care unit between 2001 and 2007.
INTERVENTIONS: Medical records of all the patients were reviewed. Demographic information, laboratory results, charted data, discharge diagnoses, physiological data, and patient outcomes were extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database using a SQL query.
MEASUREMENTS AND MAIN RESULTS: From 19,677 adult patient records, 14,524 patients met the inclusion criteria. Fifty-seven percent developed acute kidney injury during their intensive care unit stay. Inhospital mortality rates were: 13.9%, 16.4%, 33.8% for acute kidney injury 1, 2, and 3, respectively, compared with only 6.2% in patients without acute kidney injury (p < .0001). After adjusting for multiple covariates, acute kidney injury was associated with increased hospital mortality (odds ratio 1.4 and 1.3 for acute kidney injury 1 and acute kidney injury 2 and 2.5 for acute kidney injury 3; p < .0001). Using multivariate logistic regression, we found that in patients who developed acute kidney injury, urine output alone was a better mortality predictor than creatinine alone or the combination of both.
CONCLUSIONS: More than 50% of our critically ill patients developed some stage of acute kidney injury resulting in a stagewise increased mortality risk. However, the mortality risk associated with acute kidney injury stages 1 and 2 does not differ significantly. In light of these findings, re-evaluation of the Acute Kidney Injury Network staging criteria should be considered.

PMID: 21765352 [PubMed - indexed for MEDLINE]

High-frequency oscillation in adults: a utilization review.

Crit Care Med. 2011 Dec;39(12):2631-44

Authors: Adhikari NK, Bashir A, Lamontagne F, Mehta S, Ferguson ND, Zhou Q, Hand L, Czarnecka K, Cook DJ, Granton JT, Friedrich JO, Freitag A, Watpool I, Meade MO

Abstract
OBJECTIVES: High-frequency oscillation is used for adults with acute lung injury/acute respiratory distress syndrome. Given the uncertain benefits, our objective was to describe contemporary patient selection, high-frequency oscillation utilization, and outcomes.
DESIGN: Utilization review.
SETTING: Ten academic centers (Ontario, Canada; January 1, 2005-January 31, 2007).
PATIENTS: We included 190 consecutive adults treated with high-frequency oscillation and retrospectively abstracted data on patient demographics, gas exchange, hemodynamics, settings during conventional ventilation and high-frequency oscillation, adjunctive therapies, and outcomes. We used logistic regression to explore associations with oxygenation response and hemodynamic and ventilatory complications (2 hrs after high-frequency oscillation initiation) and mortality. Continuous data are reported as mean (sd) or median (quartile 1, quartile 3).
INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: Patients (60.0% male; mean age, 52; sd 17) had predominantly acute lung injury/acute respiratory distress syndrome (89.8%) and were severely ill (mean Acute Physiology and Chronic Health Evaluation II score, 28; sd, 9) and hypoxemic (mean Pao2/Fio2, 80; sd, 42). High-frequency oscillation was started a median of 2 (1, 8) days after intubation and continued for a median of 3 (2, 7) days. During high-frequency oscillation, adjunctive treatments (neuromuscular blockade, 75.6%; recruitment maneuvers, 49.5%; nitric oxide, 34.0%; steroids, 63.1%) and new barotrauma or chest tube placement (23.5%) were common. Ten patients (5.3%) had technical complications; five required a new ventilator. Reasons for stopping high-frequency oscillation included death or withdrawal of life support (39.1%), significant improvement in respiratory failure (37.6%), and inadequate improvement (23.3%). One hundred and twenty-eight of 189 patients died in hospital. Most (62.5%) had a positive oxygenation response after 2 hrs of high-frequency oscillation (mean absolute increase in PaO?/FiO?, 22 [SD, 54]; 95% confidence interval of mean 14-31). A minority had lower PaO?/FiO? (32.5%) or a hemodynamic (27.5%) or ventilatory (30.5%) complication. Older age, Acute Physiology and Chronic Health Evaluation II score, and Paco2 before high-frequency oscillation were independently associated with mortality.
CONCLUSIONS: Most patients treated with high-frequency oscillation have acute respiratory distress syndrome and severe hypoxemia that modestly improves 2 hrs after high-frequency oscillation application. However, oxygenation worsens in some patients, complications are common, and mortality is high.

PMID: 21765359 [PubMed - indexed for MEDLINE]