Pre-renal azotemia: a flawed paradigm in critically ill septic patients?
- PMID: 17464109
- DOI: 10.1159/000102008
Pre-renal azotemia: a flawed paradigm in critically ill septic patients?
Abstract
The term pre-renal azotemia (or on occasion 'pre-renal renal failure') is frequently used in textbooks and in the literature to indicate an acute syndrome characterized by the presence of an increase in the blood concentration of nitrogen waste products (urea and creatinine). This syndrome is assumed to be due to loss of glomerular filtration rate but is not considered to be associated with histopathological renal injury. Thus, the term is used to differentiate 'functional' from 'structural' acute kidney injury (AKI) where structural renal injury is taken to indicate the presence of so-called acute tubular necrosis (ATN). This paradigm is well entrenched in nephrology and medicine. However, growing evidence from experimental animal models, systematic analysis of the human and experimental literature shows that this paradigm is not sustained by sufficient evidence when applied to the syndrome of septic AKI, especially in critically ill patients. In such patients, several assumptions associated with the 'pre-renal azotemia paradigm' are violated. In particular, there is no evidence that ATN is the histopathological substrate of septic AKI, there is no evidence that urine tests can discriminate 'functional' from 'structural' AKI, there is no evidence that any proposed differentiation leads or should lead to different treatments, and there is no evidence that relevant experimentation can resolve these uncertainties. Given that septic AKI of critical illness now accounts for close to 50% of cases of severe AKI in developed countries, these observations call into question the validity and usefulness of the 'pre-renal azotemia paradigm' in AKI in general.
Similar articles
-
The meaning of transient azotemia.Contrib Nephrol. 2010;165:337-344. doi: 10.1159/000313775. Epub 2010 Apr 20. Contrib Nephrol. 2010. PMID: 20427986
-
Glomerular haemodynamics, the renal sympathetic nervous system and sepsis-induced acute kidney injury.Nephrol Dial Transplant. 2014 Dec;29(12):2178-84. doi: 10.1093/ndt/gfu052. Epub 2014 Mar 11. Nephrol Dial Transplant. 2014. PMID: 24619060 Review.
-
Histopathological changes in septic acute kidney injury in critically ill children: a cohort of post-mortem renal biopsies.Clin Exp Nephrol. 2017 Dec;21(6):1075-1082. doi: 10.1007/s10157-016-1343-z. Epub 2016 Oct 13. Clin Exp Nephrol. 2017. PMID: 27738777
-
The histopathology of septic acute kidney injury: a systematic review.Crit Care. 2008;12(2):R38. doi: 10.1186/cc6823. Epub 2008 Mar 6. Crit Care. 2008. PMID: 18325092 Free PMC article. Review.
-
Timing of initiation of dialysis in critically ill patients with acute kidney injury.Clin J Am Soc Nephrol. 2006 Sep;1(5):915-9. doi: 10.2215/CJN.01430406. Epub 2006 Jul 6. Clin J Am Soc Nephrol. 2006. PMID: 17699307
Cited by
-
Urine biochemistry assessment in critically ill patients: controversies and future perspectives.J Clin Monit Comput. 2017 Jun;31(3):539-546. doi: 10.1007/s10877-016-9871-3. Epub 2016 Apr 1. J Clin Monit Comput. 2017. PMID: 27038161 Review.
-
Fractional excretion of electrolytes in volume-responsive and intrinsic acute kidney injury in dogs: Diagnostic and prognostic implications.J Vet Intern Med. 2018 Jul;32(4):1372-1382. doi: 10.1111/jvim.15146. Epub 2018 May 17. J Vet Intern Med. 2018. PMID: 29770972 Free PMC article.
-
AKI in early sepsis is a continuum from transient AKI without tubular damage over transient AKI with minor tubular damage to intrinsic AKI with severe tubular damage.Int Urol Nephrol. 2014 Oct;46(10):2003-8. doi: 10.1007/s11255-014-0822-y. Epub 2014 Sep 5. Int Urol Nephrol. 2014. PMID: 25189154
-
Acute Kidney Injury: Diagnostic Approaches and Controversies.Clin Biochem Rev. 2016 Dec;37(4):153-175. Clin Biochem Rev. 2016. PMID: 28167845 Free PMC article. Review.
-
Plasma and urine neutrophil gelatinase-associated lipocalin in septic versus non-septic acute kidney injury in critical illness.Intensive Care Med. 2010 Mar;36(3):452-61. doi: 10.1007/s00134-009-1724-9. Epub 2009 Dec 3. Intensive Care Med. 2010. PMID: 19956924
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Medical
Miscellaneous