Variabilidad en los criterios de definición y métodos de detección de la disfunción renal en las unidades de cuidados intensivos ¿se aplican los consensos internacionales para el diagnóstico de la disfunción renal?

The Current State of the Diagnosis and Management of Acute Kidney Injury by Pediatric Critical Care Physicians

OBJECTIVES

Increasingly prevalent in pediatric intensive care, acute kidney injury imparts significant short- and long-term consequences. Despite advances in acute kidney injury research, clinical outcomes are worsening. We surveyed pediatric critical care physicians to describe the current state of acute kidney injury diagnosis and management in critically ill children.

DESIGN

Anonymous electronic questionnaire.

PARTICIPANTS

Pediatric critical care physicians from academic centers, the Pediatric Acute Lung Injury and Sepsis Investigators network, and/or the pediatric branch of Society of Critical Care Medicine.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 201 surveys initiated, 170 surveys were more than 50% completed and included in our results. The majority of physicians (74%) diagnosed acute kidney injury using serum creatinine and urine output. Acute kidney injury guidelines or criteria were used routinely by 54% of physicians; Risk, Injury, Failure, Loss, and End stage criteria were the most commonly used. Awareness of any acute kidney injury guideline or definition was associated with five-fold higher odds of using any guideline (odds ratio, 5.22; 95% CI, 1.84-14.83) and four-fold higher odds of being dissatisfied with available acute kidney injury biomarkers (odds ratio, 4.88; 95% CI, 1.58-15.05). Less than half of respondents recognized the limitations of serum creatinine. Physicians unaware of the limitations of serum creatinine had two-fold higher odds of being unaware of newer biomarker availability (odds ratio, 2.34; 95% CI, 1.14-4.79). Novel biomarkers were available to 37.6% of physicians for routine use. Physicians with access to novel biomarkers more often practiced in larger (odds ratio, 3.09; 95% CI, 1.18-8.12) and Midwestern (odds ratio, 3.38; 95% CI, 1.47-7.78) institutions. More physicians with access to a novel biomarker reported satisfaction with current acute kidney injury diagnostics (66%) than physicians without access (48%); this finding approached significance (p = 0.07).

CONCLUSIONS

Half of PICU attending physicians surveyed are not using recent acute kidney injury guidelines or diagnostic criteria in their practice. There is a positive association between awareness and clinical use of acute kidney injury guidelines. Serum creatinine and urine output are still the primary diagnostics; novel biomarkers are frequently unavailable.

Accuracy of the estimation of glomerular filtration rate within a population of critically ill patients

BACKGROUND

Accuracy of glomerular filtration rate (GFR) estimates has been questioned and several authors recommend routine use of measured renal creatinine clearance (CLCR) as a surrogate of GFR in the intensive care unit (ICU). Our purpose was to compare estimates of GFR using Cockroft-Gault (CG), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease Study (MDRD) equations with 8h-CLCR, within a population of critically ill patients with a wide range of measured CLCR.

METHODS

Through a prospective, observational study of 54 patients with normal serum creatinine (sCr) admitted to ICU, daily 8h-CLCR (reference method) and GFR estimates (644 paired samples) were matched and compared. Augmented renal clearance (ARC) was defined as 8h-CLCR >130 ml/min/1.73 m(2).

RESULTS

No significant difference was found between mean 8h-CLCR (135.5 ml/min/1.73 m(2)) and CG equation (135.7 ml/min/1.73 m(2)), but significant differences (p < 0.01) were found for the MDRD (124.4 ml/min/1.73 m(2)) and CKD-EPI (107.6 ml/min/1.73 m(2)) equations. Correlation between 8h-CLCR and all estimates was weak (R = 0.2, 0.19 and 0.34, respectively). We observed poor agreement in terms of precision (40.9, 39.8 and 33.4%, respectively). Analysing subgroups, we observed that all equations significantly underestimated 8h-CLCR >120 ml/min/1.73 m(2) and overestimated 8h-CLCR <120 ml/min/1.73 m(2) (p < 0.05). The incidence of ARC patients was 55.6%.

CONCLUSIONS

Estimates of GFR using CG, CKD-EPI and MDRD formulae are flawed in the critically ill with normal sCr, significantly underestimating renal function in those with ARC and overestimating it in those with normal or decreased 8h-CLCR. Globally, the population exhibited ARC on more than half of the ICU admission days.

Morbimortality associated to acute kidney injury in patients admitted to pediatric intensive care units

AIM

To describe the morbimortality associated to the development of acute kidney injury (AKI) defined by the pediatric adaptation of the RIFLE criteria in a Pediatric Intensive Care Unit (PICU).

DESIGN

A retrospective cohort study was carried out.

SETTING

Children admitted to a PICU in a tertiary care hospital. Patients or participants A total of 320 children admitted to a tertiary care hospital PICU during the year 2011. Neonates and renal transplant patients were excluded. Primary endpoints AKI was defined and classified according to the pediatric adaptation to the RIFLE criteria. PICU and hospital stays, use of mechanical ventilation and mortality were used to evaluate morbimortality.

RESULTS

A total of 315 children met the inclusion criteria, with a median age of 19 months (range 6-72). Of these patients, 128 presented AKI (73 reached the Risk category and 55 reached the Injury and Failure categories). Children with AKI presented a longer PICU stay (6.0 [4.0-12.5] vs. 3.5 [2.0-7.0] days) and hospital stay (17 [10-32] vs. 10 [7-15] days), and a greater need for mechanical ventilation (61.7 vs. 36.9%). The development of AKI was an independent factor of morbidity, associated with a longer PICU and hospital stay, and with a need for longer mechanical ventilation, with a proportional relationship between increasing morbidity and the severity of AKI.

CONCLUSION

The development of AKI in critically ill children is associated with increased morbimortality, which is proportional to the severity of renal injury.

[Analysis of neutrophil gelatinase-associated lipocalin in the critical patient]

OBJECTIVE

To determine if NGAL value exceeding 150 ng/mL is a good diagnostic test for acute renal failure in critically ill patients.

DESIGN

Prospective, observational cohort.

SETTING

Intensive Care Unit and Cardiac Surgery Intensive Care Service at Hospital Germans Trias I Pujol.

PARTICIPANTS

Patients admitted to the Intensive Care department the Designated days in the studio.

INTERVENTIONS

Analysis of serum creatinine blood given from 7 days prior to the start of the study, and daily during 4 weeks and by determination of NGAL urine test in frozen sample, analyzer ARCHITECT (Abbott Diagnostics) determined by immunoassay the day baseline and 2 times a week for 4 weeks, analysis of the stay and mortality.

RESULTS

A total of 529 NGAL samples were obtained from 46 patients. 37% of patients had a value of NGAL>150 ng/mL. The Sensivity of the test to diagnose acute renal failure was 69%, Specifity was 75,7%. However, the Positive Predictive Test Value was 53%, which means that 47% of patients with high NGAL did not develop AKI. A NGAL >150 mg/dL was associated with a significantly higher SOFA and a longer stay in the ICU. The mortality of patients with elevated NGAL was 58.8%.

CONCLUSIONS

A NGAL>150 ng/mL does not seem to be an excellent test for AKI in critically ill patients but is associated with a worse prognosis.

Estimating kidney function in the critically ill patients

Glomerular filtration rate (GFR) is an accepted measure for assessment of kidney function. For the critically ill patient, creatinine clearance is the method of reference for the estimation of the GFR, although this is often not measured but estimated by equations (i.e., Cockroft-Gault or MDRD) not well suited for the critically ill patient. Functional evaluation of the kidney rests in serum creatinine (Crs) that is subjected to multiple external factors, especially relevant overhydration and loss of muscle mass. The laboratory method used introduces variations in Crs, an important fact considering that small increases in Crs have serious repercussion on the prognosis of patients. Efforts directed to stratify the risk of acute kidney injury (AKI) have crystallized in the RIFLE or AKIN systems, based in sequential changes in Crs or urine flow. These systems have provided a common definition of AKI and, due to their sensitivity, have meant a considerable advantage for the clinical practice but, on the other side, have introduced an uncertainty in clinical research because of potentially overestimating AKI incidence. Another significant drawback is the unavoidable period of time needed before a patient is classified, and this is perhaps the problem to be overcome in the near future.