Author's response

^{Authors' reply}

In reply to the letter of Mallhiet al. about article entitled "Careful Selection of Predictor Variables of AKI for robust Regression Model in Intensive Care Unit" I appreciate for the considerations about our manuscript entitled "Predictors of Acute Kidney Injury and Mortality in an Intensive Care Unit".¹

We think that serum creatinine (SCr) at admission in Intensive Care Unit is important predictor of acute kidney injury (AKI), dialytic AKI and mortality. Ponceet al.² in multivariate analysis identified baseline creatinine above 1.2 as risk factors for AKI. Luoet al.³ deduced that a small increase in creatinine might be accompanied by increased mortality. Risk factors for increased level of serum creatinine and the development of AKI have been widely studied after cardiac surgery.⁴

Alkandariet al.⁵ published the first AKI study in pediatric patients to evaluate the return of SCr to baseline values after AKI and the first to explore how early SCr increases can aid in predicting AKI in this population. Baseline SCr measurement were independent predictors of AKI development. Stepwise multiple logistic regression analysis was used to evaluate the independent effect of AKI on pediatric intensive care unit mortality. In a study of children undergoing cardiac surgery, Zappitelliet al.⁶ found that early increases in SCr (< 50%) moderately predicted future overt AKI.

A preoperative risk prediction model consisting of seven predictors including lower estimated glomerular filtration rate for acute kidney injury was developed, with good predictive performance in patients undergoing orthopaedic surgery using logistic regression analysis.⁷

We understand the inclusion of SCr, urine output and electrolyte disturbances at admission in intensive care unit it can be appropriate for regression analysis and can provide useful predictors of AKI during the follow up until outcome. We recognized that the main limitations of our study were the reduced sample size. Future studies with bigger statistic power will be necessary.

References

• ¹
  Peres LA, Wandeur V, Matsuo T. Predictors of acute kidney injury and mortality in an Intensive Care Unit. J Bras Nefrol 2015;37:38-46.DOI:http://dx.doi.org/10.5935/0101-2800.20150007
  » http://dx.doi.org/10.5935/0101-2800.20150007
• ²
  Ponce D, Zorzenon CPF, Santos NY, Teixeira UA, Balbi AL. A Acute kidney injury in intensive care unit patients: a prospective study on incidence, risk factors and mortality. Rev Bras Ter Intensiva 2011;23:321-6.
• ³
  Luo X, Jiang L, Du B, Wen Y, Wang M, Xi X; Beijing Acute Kidney Injury Trial (BAKIT) workgroup. A comparasion of diferente diagnostic criteria of acute kidney injury in critically ill patients. Crit Care 2014;18:R144.
• ⁴
  Najafi M. Serum creatinine role in predicting outcome after cardiac surgery beyond acute kidney injury. World J Cardiol 2014;6:1006-21.
• ⁵
  Alkandari O, Eddington KA, Hyder A, Gauvin F, Ducruet T, Gottesman R, Phan V, et al. Acute kidney injury is an independent risk factor for pediatric intensive care unit mortality, longer length of stay and prolonged mechanical ventilation in critically ill children: a two-center retrospective cohort study. Crit Care 2011;15:R146. DOI: http://dx.doi.org/10.1186/cc10269
  » http://dx.doi.org/10.1186/cc10269
• ⁶
  Zappitelli M, Bernier PL, Saczkowski RS, Tchervenkov CI, Gottesman R, Dancea A, et al. A small post-operative rise in serum creatinine predicts acute kidney injury in children undergoing cardiac surgery. Kidney Int 2009;76:885-92. PMID: 19641482 DOI: http://dx.doi.org/10.1038/ki.2009.270
  » http://dx.doi.org/10.1038/ki.2009.270
• ⁷
  Bell S, Dekker FW, Valdiveloo T, Marwick C, Deshmukh H, Donnan PT, et al. Risk of postoperative acute kidney injury in patients undergoing orthopaedic surgery-development and validation of a risk score and effect of acute kidney injury on survival: observational cohort study. BMJ 2015;351:h5639. DOI: http://dx.doi.org/10.1136/bmj.h5639
  » http://dx.doi.org/10.1136/bmj.h5639

Publication Dates

• Publication in this collection
  Oct-Dec 2016