epidemiology of acute kidney injury … bransi...cardiopulmonary bypass (cpb) in pediatric cardiac...

pRIF

LE c

lass

i�ca

tion

Risk

Injury

Failure

Loss

End stagerenal disease

Estimated creatinine clearance (ECC) Urine output

Increased Scr X 1.5and/or

GFR decrease > 25%

Increased Scr X 2.0and/or

GFR decrease > 50%

Increased Scr X 3.0and/or

GFR decrease > 75%or

GFR < 35 ml/min/1.73 m2

Complete loss of renal function > 4 weeks

End stage renal disease

< 0.5 ml/kg/h X 8h

< 0.5 ml/kg/h X 16h

< 0.3 ml/kg/h X 24h or anury X 12h

SCr: serum creatinineGFR: glomerular �ltration rate

Background

u Acute kidney injury (AKI) is an important complication following cardiopulmonary bypass (CPB) in pediatric cardiac surgery patients

u Increased morbidity appears to be seen in AKI patients compared to non-AKI patients

u Prevalence of AKI is highly variable depending on the de� nition used

u AKI can be de� ned using the pediatric Risk Injury Failure Loss End-Stage renal disease criteria (pRIFLE)

Figure 1 Criteria used for pRIFLE classifi cation of acute kidney injury (AKI)

Objectives

u To describe the epidemiology of AKI, according to pRIFLE criteria, in our pediatric patients following cardiopulmonary bypass surgery

u To compare the outcomes of patients with and without AKI

u To identify the contribution of the presence of AKI to length of mechanical ventilation and PICU stay

Methods

u Single-center retrospective study

u Inclusion criteria:• Patients aged from 0 to 18 years admitted in our

PICU following a cardiopulmonary bypass between May 2009 and May 2011

u Exclusion criteria: • Death during surgery

• Chronic kidney failure prior to surgery

• Heart transplant prior to surgery

u Patients were classi� ed into AKI and non-AKI groups according to pRIFLE criteria• Both serum creatinine (SCr) and urine output (UO)

criteria were considered to de� ne AKI subgroups

• The GFR de� nition of AKI-Failure was not used in patients under 1 months of age

u All charts were reviewed and data entered in an Access Database and validated twice before statistical analysis using SAS® (Version 9.3)

u Descriptive statistics were inferred by one-way analysis of variance F-test with correction for unequality of variances when appropriate

u Chi-square test or Fisher exact test were performed when appropriate

u Student t-test with correction for unequality of variances were performed when appropriate

u GLM procedure with multivariate analysis of variance was applied when appropriate

EPIDEMIOLOGY OF ACUTE KIDNEY INJURY FOLLOWING CARDIOPULMONARY BYPASS IN PEDIATRIC CARDIAC SURGERY PATIENTS

Myriam Bransi, MD • J-Philippe Proulx-Gauthier, MD • David Simonyan, MSc • Dennis Bailey, MD, MSc • Marc-André Dugas, MD, MSc

Results

Conclusions

u AKI is highly prevalent following cardiopulmonary bypass in pediatric cardiac surgery

u Compared to non-AKI group, AKI patients were:

• Younger

• Had longer duration of cardiopulmonary bypass

• Had higher Pediatric Risk of Mortality scores (PRISM)

• Had longer mechanical ventilation duration

• Had longer intensive care unit length of stay

u AKI explains 17% of the PICU length of stay and 11% of mechanical duration and thus is associated to a signi� cant clinical burden in these patients

u Speci� c modi� able risk factors and therapeutic approaches for AKI still need to be identi� ed in order to prevent and treat AKI in pediatric patients following CPB cardiac surgery

Table 1 Characteristics and Outcomes of Patients With and Without AKI According to pRIFLE

Figure 2 Flow Diagram for the Selection Process of Patients with AKI Table 3 Contribution of the Presence of AKI to Secondary Outcomes

Variability attributable to AKIOutcomes

Length of Stay in PICU 16.57% p < 0.0001

Length of mecanical ventilation

10.77% p = 0.001

194 charts reviewed

Excluded n = 53u No cardiopulmonary bypass (n = 49)

u Death during surgery (n = 1)

u Over 18 years old (n = 1)

u Incomplete �les (n = 2)

Included n = 141

No AKIn = 85

AKI SCr and/or UO n = 56

AKI-Injuryn = 11

AKI-Failuren = 7

AKI-Riskn = 38

No AKI(60%, n=85)

pRIFLEAKI-pooled(40%, n=56)

ρ values

Age (years) 1.6 0.5< 0.0004

Median (IQR) (0.65-8.03) (0.08-1.71)

Gender (males) 44 (52%) 30 (54%) NS

RACHS 2 2NS

Median (IQR) (2-3) (2-3)

Mortality 1 (1.2%) 1 (1.8%) NS

Length of CPB 98 140< 0.0001

Mean (minutes ± 95%CI) (87-109) (123-158)

Maximal PICU creatinine 39 53< 0.0005

Mean (µmol/L ± 95%CI) (34-44) (47-59)

PRISM score 8 100.03

Median (IQR) (6-10) (7.5-12)

PELOD score 2 120.0013

Median (IQR) (2-12) (2-12)

Length of mechanical ventilation

23 560.045

Mean (hours ± 95%CI) (7-39) (23-89)

Length of PICU stay 60 1300.0005

Mean (hours ± 95%CI) (43-77) (94-166)

RACHS = risk adjustment in congenital heart surgeryPRISM = pediatric risk of mortality score, IQR = interquartile rangePICU = pediatric intensive care unit, CPB = cardiopulmonary bypassPELOD = pediatric logistic organ dysfunction score

Table 2 Characteristics and Outcomes of Patients With pRIFLE AKI Subgroups Compared to Non-AKI Patients

No AKI(60%, n=85)

pRIFLERisk

(27%, n=38)

pRIFLEInjury

(8%, n=11)

pRIFLEFailure

(5%, n=7)ρ values

Age (years) 1.6 b,d 0.69 a,d 0.31 0.26 a,b

< 0.0001Median IQR (0.6-8.0) (0.2-2.0) (0-3.9) (0.07-0.5)

Gender (males) 44 (52%) 19 (50%) 6 (55%) 5 (71%) NS

RACHS 2 c 2 c 3 a,b 20.0394

Median IQR (2-3) (2-3) (2-4) (2-3)

Mortality 1 (1.2%) 0 1 (9.1%) 0 NS

Length of CPB 98 b,c 127 a,c 188 a,b 138<0.0001

Mean (minutes ± 95%CI) (87-109) (107-147) (143-233) (95-181)

Maximal PICU creatinine 39 c,d 41 c,d 68 a,b,d 93 a,b,c

<0.0001Mean (µmol/L ± 95%CI) (34-44) (37- 46) (57-78) (81-106)

PRISM score 8 c 9.5 11 a 110.0132

Median IQR (6-10) (6-11) (10-14) (8-15)

PELOD score 2 c 12 c 12 a,b 12< 0.0001

Median (IQR) (2-12) (2-12) (2-12) (2-12)

Length of mechanical ventilation

23 29 138 750.1595

Mean (hours ± 95%CI) (7-39) (19-39) (-35-312) (7-143)

Length of PICU stay 60 b 99 a 194 1950.0043

Mean (hours ± 95%CI) (43-77) (76-122) (55-332) (0.5-390)

RACHS = risk adjustment in congenital heart surgeryPRISM = pediatric risk of mortality score, IQR = interquartile rangePICU = pediatric intensive care unit, CPB = cardiopulmonary bypassPELOD = pediatric logistic organ dysfunction score

a = signi� cantly different from no AKIb = signi� cantly different from Risk-AKIc = signi� cantly different from Injury-AKId = signi� cantly different from Failure-AKI