Incidence and prognostic implications of acute kidney injury on admission in patients with community-acquired pneumonia.
BACKGROUND
A consensus definition of acute kidney injury (AKI)-the risk, injury, failure, loss, and end-stage kidney disease (RIFLE) classification-predicts mortality in general hospital and ICU populations. We aimed to assess its value on admission in patients with community-acquired pneumonia (CAP).


METHODS
A prospective observational study with CAP was carried out. We classified each patient according to his or her maximum RIFLE class using admission creatinine (risk, ≥ 1.5 × baseline creatinine; injury, ≥ 2 × baseline; failure, ≥ 3 × baseline; no-AKI, < 1.5 × baseline). Outcomes were 30-day mortality, requirement for mechanical ventilation and inotropic support (MV/IS), and requirement for renal replacement therapy (RRT).


RESULTS
A total of 1,241 patients were included (no-AKI, 1,018; risk, 130; injury, 63; failure, 30). On multivariate analysis, factors predicting development of AKI include severity of pneumonia (adjusted odds ratio [AOR], 1.74; 95% CI, 1.46-2.08; P < .0001), elevated C-reactive protein (AOR, 1.04; 95% CI, 1.03-1.06; P < .0001), and prior use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-II-receptor blockers (AIIBs) (AOR, 1.77; 95% CI, 1.19-2.58; P = .005). Adjusting for severity of pneumonia, RIFLE criteria independently predicted 30-day mortality (AOR, 1.48; 95% CI, 1.15-1.91; P = .002), requirement for MV/IS (AOR, 2.22; 95% CI, 1.74-2.83; P < .0001), and RRT (AOR, 3.20; 95% CI, 2.01-5.11; P < .0001). Prior use of ACEIs or AIIBs was not associated with adverse outcome in either the entire cohort or patients without AKI.


CONCLUSIONS
The RIFLE classification is a simple tool to assess and classify AKI on admission and independently predicts 30-day mortality and the need for MV/IS and RRT in patients with CAP.
Akram
Ahsan R
AR
Department of Respiratory Medicine, New Royal Infirmary of Edinburgh, Edinburgh, Scotland. ahsan.akram@hotmail.co.uk
Singanayagam
Aran
A
Choudhury
Gourab
G
Mandal
Pallavi
P
Chalmers
James D
JD
Hill
Adam T
AT
D058186:Acute Kidney Injury / Q000145:classification / Q000209:etiology* / Q000628:therapy; D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D016009:Chi-Square Distribution; D017714:Community-Acquired Infections / Q000150:complications* / Q000628:therapy; D003404:Creatinine / Q000032:analysis; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications* / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D017582:Renal Replacement Therapy; D012121:Respiration, Artificial; D012307:Risk Factors; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D015415:Biomarkers; D002097:C-Reactive Protein; D003404:Creatinine