Incorporating Oliguria Into the Diagnostic Criteria for Acute Kidney Injury After On-Pump Cardiac Surgery: Impact on Incidence and Outcomes

doi:10.1053/j.jvca.2012.12.017

Journal of Cardiothoracic and Vascular Anesthesia

Volume 27, Issue 6, December 2013, Pages 1145-1152

https://doi.org/10.1053/j.jvca.2012.12.017 Get rights and content

Objectives

Consensus definitions represent an important step toward defining the epidemiology of acute kidney injury (AKI). However, the oliguric component of these definitions remains of uncertain impact and utility after cardiac surgery. The authors sought to define the specific impact of oliguric criteria, both alone and in combination with serum creatinine criteria, on the observed incidence of AKI and associated adverse outcomes following adult cardiac surgery.

Design

Retrospective observational study over a 1-year period.

Setting

Academic medical institution.

Participants

A total of 311 adult patients undergoing elective valve and/or coronary artery bypass graft surgery with cardiopulmonary bypass.

Interventions

No interventions were performed as part of the study.

Measurements and Main Results

Hourly urine output and daily serum creatinine were recorded in the 2 days following surgery. AKI was defined by Acute Kidney Injury Network oliguric and serum creatinine criteria. Defined by serum creatinine criteria alone, the incidence of AKI was 17.7% and was associated strongly with in-hospital mortality (odds ratio 6.6, 95% confidence interval 1.4-30.5, p = 0.02) and renal replacement therapy (odds ratio 12.7, 95% confidence interval 2.4-67.3, p = 0.003) as well as time to discharge from the intensive care unit and hospital. Defined by oliguric criteria alone through 48 hours following surgery, the incidence of AKI dramatically increased to 55.6% but was not associated with mortality, renal replacement therapy, or time to discharge.

Conclusions

Acute Kidney Injury Network oliguric criteria applied over 48 hours after surgery dramatically increased the measured incidence of AKI after cardiac surgery, but was not associated with adverse outcomes.

Section snippets

Methods

Using an existing retrospective cohort of all adult cardiac surgery patients within the authors' institution between July 22, 2008 and July 22, 2009, the authors identified patients who underwent elective valve and/or coronary artery bypass graft surgery with the use of cardiopulmonary bypass (CPB) following cardiovascular catheterization within their institution during the preceding 6 months. Patients who required preoperative RRT, intraoperative contrast administration, the presence of an

Results

The study cohort comprised 311 patients with an average age of 69 (range, 32-94) years, a slight preponderance of men (56.9%) and a preoperative estimated glomerular filtration rate<60 mL/min/1.73m² in 28.3% of the cohort. Serum creatinine was available for 308 patients (99.0%) prior to surgery and 304 patients (97.7%) on both days 1 and 2 following surgery. Urine output data were available for 310 patients (99.7%) through each of the first 12 hours, 300 patients (96.5%) through 24 hours, and

Discussion

Components of the AKIN criteria were analyzed in adult patients undergoing elective cardiac surgery with CPB to determine the individual contributions from increases in serum creatinine and oliguria on the measured incidence of AKI as well as associated adverse outcomes after surgery. Using serum creatinine criteria (AKI_Cr), stage 1 or greater AKI was diagnosed in 17.7% of the study cohort and was associated consistently with increased mortality and RRT as well as increased time to discharge

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Cited by (48)

Association Between Changes in Norepinephrine Infusion Rate and Urinary Oxygen Tension After Cardiac Surgery
2023, Journal of Cardiothoracic and Vascular Anesthesia
To determine if the administration of norepinephrine to patients recovering from on-pump cardiac surgery is associated with changes in urinary oxygen tension (PO₂), an indirect index of renal medullary oxygenation.
Single center, prospective observational study.
Surgical intensive care unit (ICU).
A nonconsecutive sample of 93 patients recovering from on-pump cardiac surgery.
In the ICU, norepinephrine was the most commonly used vasopressor agent (90% of patients, 84/93), with fewer patients receiving epinephrine (48%, 45/93) or vasopressin (4%, 4/93). During the 30-to-60-minute period after increasing the infused dose of norepinephrine (n = 89 instances), urinary PO₂ decreased by (least squares mean ± SEM) 1.8 ± 0.5 mmHg from its baseline level of 25.1 ± 1.1 mmHg. Conversely, during the 30-to-60-minute period after the dose of norepinephrine was decreased (n = 134 instances), urinary PO₂ increased by 2.6 ± 0.5 mmHg from its baseline level of 22.7 ± 1.2 mmHg. No significant change in urinary PO₂ was detected when the dose of epinephrine was decreased (n = 21). There were insufficient observations to assess the effects of increasing the dose of epinephrine (n = 11) or of changing the dose of vasopressin (n <4).
In patients recovering from on-pump cardiac surgery, changes in norepinephrine dose are associated with reciprocal changes in urinary PO₂, potentially reflecting an effect of norepinephrine on renal medullary oxygenation.
Prognostic Utility of KDIGO Urine Output Criteria After Cardiac Surgery
2021, Journal of Cardiothoracic and Vascular Anesthesia
Citation Excerpt :
Because prior AKI is a risk factor for chronic kidney disease and end-stage renal disease,25,26 these data questioned the utility of KDIGOUO for both short- and long-term perioperative riskstratification. Others also have suggested that urine output criteria overclassify AKI after cardiac surgery.3,27 A comparison of outcomes within each AKI stage demonstrated that patients meeting only KDIGOCr or both KDIGOCr and KDIGOUO had worse outcomes than patients meeting KDIGOUO alone.3
Kidney Disease: Improving Global Outcomes (KDIGO) guidelines include assessment of creatinine and urine output to identify acute kidney injury (AKI). Whether urine output is an accurate indicator of AKI after cardiac surgery, however, is unclear. The authors’ goal was to examine whether cardiac surgery patients who fulfilled criteria for AKI by KDIGO urine output criteria also demonstrated kidney injury by elevated creatinine, other kidney biomarkers, or had worse clinical outcomes.
Secondary analysis of prospectively collected data from a clinical trial, “6% Hydroxyethyl starch 130/0.4 in Cardiac Surgery (NCT02192502).”
Academic, quaternary care hospital.
Patients undergoing elective aortic valve replacement
None
One hundred forty-one patients were classified into AKI stage by KDIGO urine output criteria within 24 hours after surgery. Kidney biomarkers (serum creatinine, urinary neutrophil gelatinase-associated lipocalin [NGAL], urinary interleukin-18 [IL-18]) and hospital and intensive care unit length of stay were analyzed across AKI stages. Urine output criteria classified four times as many patients with AKI than creatinine criteria (95 [67%] v 21 [15%]). Most patients meeting KDIGO urine output criteria for AKI postoperatively did not satisfy KDIGO creatinine criteria for AKI within one week (77 of 95 [81%]) or six-to-12 months (27 of 29 [93%]). Higher AKI stage assessed by urine output was not associated with higher NGAL, IL-18, or longer hospital or intensive care unit stays.
Acute kidney injury classified by KDIGO urine output criteria was not associated with other biomarkers of kidney injury or worse patient outcomes. These data suggested that KDIGO urine output criteria after cardiac surgery may overclassify AKI stage; further research is needed.
The impact of acute kidney injury by serum creatinine or urine output criteria on major adverse kidney events in cardiac surgery patients
2021, Journal of Thoracic and Cardiovascular Surgery
Citation Excerpt :
By using a large multi-hospital cohort of patients undergoing cardiac surgery, we investigated the impact of AKI by both UO and SC criteria as per the KDIGO guideline on the rates of MAKE180. As shown in previous studies of patients undergoing cardiac surgery,7,11 oliguria meeting the UO criteria for AKI was common, occurring in 4983 patients (75.1%). However, this oliguria was accompanied by an increase in SC in less than half of patients.
Oliguria after cardiac surgery remains of uncertain clinical significance. Therefore, we investigated the relationship of acute kidney injury severity across urine output and creatinine domains with the risk for major adverse kidney events at 180 days. We aimed to determine the impact of acute kidney injury after cardiac surgery.
In a retrospective multicenter study, we investigated the relationship of acute kidney injury severity across urine output and creatinine categories with the risk for major adverse kidney events at 180 days—the composite of death, dialysis, and persistent renal dysfunction—using a large database of patients undergoing cardiac surgery at 1 of 5 hospitals within the regional medical system. We analyzed electronic records from 6637 patients treated between 2008 and 2014, of whom 5389 (81.2%) developed any acute kidney injury within 72 hours of surgery. We stratified patients by levels of urine output or serum creatinine according to Kidney Disease Improving Global Outcomes criteria for acute kidney injury.
Major adverse kidney events at 180 days increased from 4.5% for no acute kidney injury to 61.3% for stage 3 acute kidney injury (P < .001). Death or dialysis by day 180 was 2.4% for those with no acute kidney injury and 46.7% for those with acute kidney injury stage 3 (P < .001). Isolated oliguria was common (42.6%), and isolated azotemia was rare (6.1%). Even stage 1 acute kidney injury by oliguria alone was associated with an increased risk of major adverse kidney events at 180 days (odds ratio, 1.76; 1.20-2.57; P = .004), mainly driven by persistent renal dysfunction (odds ratio, 2.01; 1.26-3.18; P = .003).
Acute kidney injury is common in patients undergoing cardiac surgery, and even milder forms of acute kidney injury, including isolated stage 1 oliguria, are associated with adverse long-term consequences.
Intraoperative Urinary Biomarkers and Acute Kidney Injury After Cardiac Surgery
2021, Journal of Cardiothoracic and Vascular Anesthesia
To evaluate the association of intraoperative urinary biomarker excretion during cardiac surgery and the subsequent development of acute kidney injury (AKI).
Prospective, nonrandomized, observational study.
Single tertiary-level, university-affiliated hospital.
Ninety patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).
None.
Urinary samples were collected every 30 minutes intraoperatively and then at four, 12, and 24 hours after CPB. Samples were measured for interleukin 18 (IL-18), kidney injury molecule-1 (KIM1), and creatinine concentrations. Urinary biomarker excretion (raw and indexed to creatinine) for four intraoperative and three postoperative points were compared between patients with and those without subsequent AKI defined by increased serum creatinine concentration ≥0.3 mg/dL within the first 48 hours or ≥1.5 times baseline within seven days. Raw and indexed median IL-18 values were similar between AKI groups at all intraoperative points, but became significantly different at 12 hours after CPB. Raw and indexed median KIM1 values were significantly different between AKI groups at multiple intraoperative points and at four and 12 hours after CPB. During intraoperative and postoperative points, patients in the fourth quartile of KIM1 excretion had greater AKI incidence and longer intensive care and hospital lengths of stay than those in the first quartile. Only postoperatively did the differences in these outcomes between the fourth and first quartile of IL-18 excretion occur.
Intraoperative KIM1 but not IL-18 excretion was associated with postoperative development of AKI.
Preservation of Renal Function
2021, Perioperative Medicine: Managing for Outcome, Second Edition
Acute kidney injury (AKI) remains a frequent and serious complication of surgical procedures and critical illness that is consistently associated with worse outcomes and increased long-term morbidity and mortality. Much work has gone into finding kidney protective measures with disappointingly few therapeutic options available to prevent or to treat AKI. Research has defined some effective kidney protective practices and the purpose of this chapter is to help the clinician to differentiate better clinical practices that are either ineffective, detrimental, or protective to the kidney. The chapter will first provide an introduction to kidney physiology with particular focus on areas that make it vulnerable to injury. The chapter will then shift focus to diagnosis of kidney injury including definitions and early biomarkers that can help risk stratify patients. Then, specific mechanisms of postoperative and critical illness-associated kidney injury will be outlined. The rest of the chapter will review evidence from renal-protective research studies pertinent to the preoperative, intraoperative, and postoperative periods. After reading this chapter, the clinician should have a more robust framework for adoption (mostly avoidance) of renal protective practices (stratified based on level of evidence available) to guide their clinical practice.
Markers of Poor Prognosis in Patients Requiring Continuous Renal Replacement Therapy After Cardiac Surgery
2020, Journal of Cardiothoracic and Vascular Anesthesia
Acute kidney injury requiring renal replacement therapy after cardiac surgery has an incidence of 2% to 15%, and mortality in affected patients approximates 50%. The authors aimed to study the determinants of poor prognosis in patients receiving continuous renal replacement therapy (CRRT) after cardiac surgery.
Retrospective, observational single-center study.
Tertiary care, university hospital.
Cardiac surgery patients admitted to the intensive care unit (ICU) needing postoperative CRRT between January 1, 2010, and September 31, 2019.
Predictors of mortality were examined using groupwide comparisons between ICU survivors versus nonsurvivors and univariate and multivariate Cox proportional hazards models.
During the study period, 67 cardiac surgery patients without prior maintenance dialysis required CRRT postoperatively. ICU mortality was 47.7% and 90-day mortality was 58.2%. Only 37.3% of patients were alive at 1 year after surgery. Blood lactate at the start of dialysis was the most significant predictor of ICU and overall mortality. Eighty-seven percent of patients with lactate >3 mmol/L died in the ICU compared with 27.3% of patients with lactate ≤3 mmol/L (p < 0.0001). In patients with lactate exceeding 5.3 mmol/L, ICU mortality was 100%. In a stepwise multivariate Cox proportional hazards model, the association with mortality remained significant for lactate at the start of CRRT (per 1 mmol/L, hazard ratio [HR] 1.19 [95% confidence interval {CI} 1.11-1.28], p < 0.0001), troponin T on the first postoperative morning (per 0.1 µg/L, HR 1.004 [95% CI 1.001-1.008], p = 0.01), and 72-hour fluid balance (per 1000 mL, HR 1.12 [95% CI 1.04-1.21], p = 0.005).
Blood lactate at the start of dialysis was the most significant predictor of ICU and overall mortality in patients with CRRT after cardiac surgery.

View all citing articles on Scopus

: Funding Sources: This work was supported by intramural funding from the Department of Anesthesiology and Department of Surgery, Columbia University, New York, NY.

View full text

Incorporating Oliguria Into the Diagnostic Criteria for Acute Kidney Injury After On-Pump Cardiac Surgery: Impact on Incidence and Outcomes

Objectives

Design

Setting

Participants

Interventions

Measurements and Main Results

Conclusions

Section snippets

Methods

Results

Discussion

Ann Thorac Surg

J Thorac Cardiovasc Surg

Ann Thorac Surg

Am J Kidney Dis

Kidney Int

Costs and outcomes of acute kidney injury (AKI) following cardiac surgery

Nephrol Dial Transplant

Acute kidney injury is associated with increased long-term mortality after cardiothoracic surgery

Circulation

Acute kidney injury after cardiac surgery: Focus on modifiable risk factors

Circulation

Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: A prospective cohort study

J Am Soc Nephrol