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Post cardiac surgery acute kidney injury: a woebegone status rejuvenated by the novel biomarkers.

Jayaraman R, Sunder S, Sathi S, Gupta VK, Sharma N, Kanchi P, Gupta A, Daksh SK, Ram P, Mohamed A - Nephrourol Mon (2014)

Bottom Line: It significantly increases morbidity and mortality.Novel urinary biomarkers are emerging which help in rapid diagnosis thus reducing the morbidity and mortality.Biomarkers of our study were neutrophil gelatinase-associated lipocalin (NGAL) and Interleukin-18 (IL-18).

View Article: PubMed Central - PubMed

Affiliation: Department of Nephrology, Dr. Ram Manohar Lohia Hospital, Indraprastha University, New Delhi, India.

ABSTRACT

Background: Acute kidney injury (AKI) is common after cardiac surgery, the incidence varying between 7.7% and 28.1%. It significantly increases morbidity and mortality. Creatinine considerably delays the diagnosis with its own attended demerits. Novel urinary biomarkers are emerging which help in rapid diagnosis thus reducing the morbidity and mortality. Biomarkers of our study were neutrophil gelatinase-associated lipocalin (NGAL) and Interleukin-18 (IL-18).

Objectives: To find out the incidence of AKI in post-cardiac surgery patients in our hospital, the ability of the two biomarkers in early diagnosis in predicting the severity of AKI based on RIFLE's criteria and their ability to discriminate pre-renal from intrinsic AKI.

Patients and methods: One-hundred patients who underwent cardiac surgery were selected. Midstream urine samples were collected at 3 time intervals (baseline before surgery, 24 hours and 7 days after surgery). Biomarkers were measured by ELISA using BIORAD processors. Fractional excretion of sodium and urea were used to discriminate pre-renal from intrinsic AKI.

Results: Out of 100 patients, 31 had AKI, 11 being pre-renal and 20 intrinsic AKI. Four patients required renal replacement therapy (12.9% among AKI cases and 4% in the overall study cohort). Four among 31 expired in intensive care unit. Identifiable risk factors for AKI included insulin requiring diabetes mellitus, chronic obstructive pulmonary disease, increased cardio-pulmonary bypass time, combined valvular surgery and coronary artery bypass grafting, employment of intra-aortic balloon counter pulsation, left main coronary artery occlusion and an ejection fraction of < 40%. NGAL was extremely sensitive (area under curve-0.96) in detecting intrinsic AKI at 24 hours followed by IL-18 ratio with an area under curve of 0.89. Creatinine at 24 hours was able to detect only 31.6% of intrinsic AKI. None of the pre-renal cases showed rise in the urinary biomarker levels. Patients with higher stages of AKI had higher levels of both biomarkers than those at lower stages.

Conclusions: NGAL and IL-18 obviated the disadvantages of creatinine. They were efficient in early detection of AKI, in differentiating pre-renal from intrinsic AKI and in predicting the severity of AKI reliably in post-cardiac surgery patients.

No MeSH data available.


Related in: MedlinePlus

Receiver Operator Curve For Adjusted Neutrophil Gelatinase Associated Lipocalin at 24 Hours For Intrinsic Acute Kidney Injury AloneAn AUC of 0.96 was observed.
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fig11889: Receiver Operator Curve For Adjusted Neutrophil Gelatinase Associated Lipocalin at 24 Hours For Intrinsic Acute Kidney Injury AloneAn AUC of 0.96 was observed.

Mentions: In all 31 cases of AKI, NGAL > 60 pg/mL at 24 hours was seen in 72% (95% CI, 50.4% to 87.1%) (vs. GFR, P = 0.01, comparison of proportions). IL-18 > 250 pg/mL at 24 hours is seen in 48% (95% CI, 28.3% to 68.3%) (vs. GFR, P = 0.39, comparison of proportions). Twenty-four hours NGAL + IL-18 detected AKI in 72% (95% CI, 50.4% to 87.1%), and 24 hours NGAL + creatinine detected AKI in 80% (95% CI, 58.7% to 92.4%) (P = 0.51, comparison of proportions).Twenty-four hours NGAL alone detected AKI in 72% (95% CI, 50.4% to 87.1%), whereas 24 hours IL-18 alone detected AKI in 48% (95% CI, 28.3% to 68.3%) (P = 0.08, comparison of proportions). Neither the combination of NGAL and IL-18 nor NGAL + creatinine was found to be superior to NGAL alone in detecting AKI at 24 hours. The adjusted biomarker level to creatinine was not found to be superior to unadjusted value for NGAL in detecting AKI at 24 hours but was found to be superior for IL-18 NGAL and IL-18 being tubular markers are supposed to rise in the urine only when there is intrinsic tubular AKI and not in pre-renal AKI. Segregating these cases as 20 intrinsic and 11 pre-renal AKI and extrapolating the biomarker levels with these categories produced a more refined status for these biomarkers (Figures 1 and 2).


Post cardiac surgery acute kidney injury: a woebegone status rejuvenated by the novel biomarkers.

Jayaraman R, Sunder S, Sathi S, Gupta VK, Sharma N, Kanchi P, Gupta A, Daksh SK, Ram P, Mohamed A - Nephrourol Mon (2014)

Receiver Operator Curve For Adjusted Neutrophil Gelatinase Associated Lipocalin at 24 Hours For Intrinsic Acute Kidney Injury AloneAn AUC of 0.96 was observed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109123&req=5

fig11889: Receiver Operator Curve For Adjusted Neutrophil Gelatinase Associated Lipocalin at 24 Hours For Intrinsic Acute Kidney Injury AloneAn AUC of 0.96 was observed.
Mentions: In all 31 cases of AKI, NGAL > 60 pg/mL at 24 hours was seen in 72% (95% CI, 50.4% to 87.1%) (vs. GFR, P = 0.01, comparison of proportions). IL-18 > 250 pg/mL at 24 hours is seen in 48% (95% CI, 28.3% to 68.3%) (vs. GFR, P = 0.39, comparison of proportions). Twenty-four hours NGAL + IL-18 detected AKI in 72% (95% CI, 50.4% to 87.1%), and 24 hours NGAL + creatinine detected AKI in 80% (95% CI, 58.7% to 92.4%) (P = 0.51, comparison of proportions).Twenty-four hours NGAL alone detected AKI in 72% (95% CI, 50.4% to 87.1%), whereas 24 hours IL-18 alone detected AKI in 48% (95% CI, 28.3% to 68.3%) (P = 0.08, comparison of proportions). Neither the combination of NGAL and IL-18 nor NGAL + creatinine was found to be superior to NGAL alone in detecting AKI at 24 hours. The adjusted biomarker level to creatinine was not found to be superior to unadjusted value for NGAL in detecting AKI at 24 hours but was found to be superior for IL-18 NGAL and IL-18 being tubular markers are supposed to rise in the urine only when there is intrinsic tubular AKI and not in pre-renal AKI. Segregating these cases as 20 intrinsic and 11 pre-renal AKI and extrapolating the biomarker levels with these categories produced a more refined status for these biomarkers (Figures 1 and 2).

Bottom Line: It significantly increases morbidity and mortality.Novel urinary biomarkers are emerging which help in rapid diagnosis thus reducing the morbidity and mortality.Biomarkers of our study were neutrophil gelatinase-associated lipocalin (NGAL) and Interleukin-18 (IL-18).

View Article: PubMed Central - PubMed

Affiliation: Department of Nephrology, Dr. Ram Manohar Lohia Hospital, Indraprastha University, New Delhi, India.

ABSTRACT

Background: Acute kidney injury (AKI) is common after cardiac surgery, the incidence varying between 7.7% and 28.1%. It significantly increases morbidity and mortality. Creatinine considerably delays the diagnosis with its own attended demerits. Novel urinary biomarkers are emerging which help in rapid diagnosis thus reducing the morbidity and mortality. Biomarkers of our study were neutrophil gelatinase-associated lipocalin (NGAL) and Interleukin-18 (IL-18).

Objectives: To find out the incidence of AKI in post-cardiac surgery patients in our hospital, the ability of the two biomarkers in early diagnosis in predicting the severity of AKI based on RIFLE's criteria and their ability to discriminate pre-renal from intrinsic AKI.

Patients and methods: One-hundred patients who underwent cardiac surgery were selected. Midstream urine samples were collected at 3 time intervals (baseline before surgery, 24 hours and 7 days after surgery). Biomarkers were measured by ELISA using BIORAD processors. Fractional excretion of sodium and urea were used to discriminate pre-renal from intrinsic AKI.

Results: Out of 100 patients, 31 had AKI, 11 being pre-renal and 20 intrinsic AKI. Four patients required renal replacement therapy (12.9% among AKI cases and 4% in the overall study cohort). Four among 31 expired in intensive care unit. Identifiable risk factors for AKI included insulin requiring diabetes mellitus, chronic obstructive pulmonary disease, increased cardio-pulmonary bypass time, combined valvular surgery and coronary artery bypass grafting, employment of intra-aortic balloon counter pulsation, left main coronary artery occlusion and an ejection fraction of < 40%. NGAL was extremely sensitive (area under curve-0.96) in detecting intrinsic AKI at 24 hours followed by IL-18 ratio with an area under curve of 0.89. Creatinine at 24 hours was able to detect only 31.6% of intrinsic AKI. None of the pre-renal cases showed rise in the urinary biomarker levels. Patients with higher stages of AKI had higher levels of both biomarkers than those at lower stages.

Conclusions: NGAL and IL-18 obviated the disadvantages of creatinine. They were efficient in early detection of AKI, in differentiating pre-renal from intrinsic AKI and in predicting the severity of AKI reliably in post-cardiac surgery patients.

No MeSH data available.


Related in: MedlinePlus