Draft

63  AKI In The ICU

63.1 What this covers

  • Estimating GFR
  • muscle mass, age, gender, and race all effect concentration
  • underfeeding, bedrest, and hyper catabolism would all be expected to change creatinine generation

63.2 Learning objectives

  • Estimating GFR
  • muscle mass, age, gender, and race all effect concentration
  • underfeeding, bedrest, and hyper catabolism would all be expected to change creatinine generation
  • even beyond creatinine kinetics, fluid resuscitation would be expected to change creatinine by changing it’s volume of distribution (same with muscle loss during a long hospitalization)
  • steady state equations (e.g. C-G, CKD-EPI) assume stable sCr, which is often not the case in the ICU.

63.3 Bottom line / summary

  • All commonly used equations for estimating GFR in the ICU are unacceptably precise and biased toward overestimating GFR.
  • https://journals.lww.com/ccmjournal/Fulltext/2020/12000/MeasuredandEstimatedGlomerularFiltrationRate.54.aspx
  • muscle mass, age, gender, and race all effect concentration
  • underfeeding, bedrest, and hyper catabolism would all be expected to change creatinine generation
  • even beyond creatinine kinetics, fluid resuscitation would be expected to change creatinine by changing it’s volume of distribution (same with muscle loss during a long hospitalization)

63.4 Approach

  1. muscle mass, age, gender, and race all effect concentration
  2. underfeeding, bedrest, and hyper catabolism would all be expected to change creatinine generation
  3. even beyond creatinine kinetics, fluid resuscitation would be expected to change creatinine by changing it’s volume of distribution (same with muscle loss during a long hospitalization)
  4. steady state equations (e.g. C-G, CKD-EPI) assume stable sCr, which is often not the case in the ICU.

63.5 Red flags / when to escalate

  • TODO: List red flags that require urgent escalation.

63.6 Common pitfalls

  • TODO: Capture common errors or missed steps.

63.7 References

  • https://journals.lww.com/ccmjournal/Fulltext/2020/12000/MeasuredandEstimatedGlomerularFiltrationRate.54.aspx

63.8 Source notes

63.8.1 AKI In The ICU

64 AKI in the ICU

64.1 Estimating GFR

All commonly used equations for estimating GFR in the ICU are unacceptably precise and biased toward overestimating GFR.

  • muscle mass, age, gender, and race all effect concentration
  • underfeeding, bedrest, and hyper catabolism would all be expected to change creatinine generation
  • even beyond creatinine kinetics, fluid resuscitation would be expected to change creatinine by changing it’s volume of distribution (same with muscle loss during a long hospitalization)
  • steady state equations (e.g. C-G, CKD-EPI) assume stable sCr, which is often not the case in the ICU.

https://journals.lww.com/ccmjournal/Fulltext/2020/12000/Measured_and_Estimated_Glomerular_Filtration_Rate.54.aspx

64.2 Source materials