Wessex ICS Blog

Regional ICM teaching - Renal

Date: 23rd October 2014
Facilitators: Dr Jamie Plumb & Dr James McNicholas
Summary written by: Dr Jamie Plumb

intrinsic renal failure not to be missed in an ICU presentation with AKI, and diagnostic work up prior to assessment by a renal physician’
Dr Adam Kirk Renal Consultant - Queen Alexandra Hospital Portsmouth

Dr Kirk started of by talking about some of the differences between renal physicians and intensivists. He then touched on when they intervene with their CKD patients. Stating that renal patients will not die from their renal failure any longer but of some other disease, more often than not cardiovascular in origin. He mentioned the classification of AKI which was a common theme for the afternoon. He classified the causes of renal failure- pre, intrinsic and post and then focused on
intrinsic renal failure: discussing their features, causes and treatments.
• Acute Tubular Necrosis (ATN)
• TubuloInterstitial Nephritis (TIN)
• Glomerular Nephritis (GN)
• Vasculitis

The importance of the rapid treatment of anti- GBM disease was discussed. He then talked about renal transplant patients, either with problems directly related
to the transplant or other problems presenting to the ICU. Important points to know such as the time since the transplant and level of success.

The classic acute rejection triad of Classic triad: Fever, Oliguria, graft tenderness
Prompt Tx essential. Risk factors were discussed. The time course post transplant for when certain infections are likeliest was
reviewed. He ended by pondering when we should call them as intensivists,
  • When there is a renal diagnosis requiring renal intervention/advice
  • When there may be and further brains/interference may benefit the patient
  • prognosis
  • Known renal patient esp Transplant

Dr Kirk’s presentation slides are available here with his permission. Please click on slide below to view

Screenshot 2014-12-29 19.26.24


The renal ICM quiz
Dr Jamie Plumb - Specialty Registrar in ICM

The slightly controversial quiz contained a mixture of questions; it started off with some of the basics around the modes used within critical care and progressed
towards some rather more debatable single best answer questions (SBAs). For those that are pre the final FRCA and/or the FICM exam then they both contain
SBA questions and they do require a fair amount of technique!

Dr Plumb’s presentation slides (with answers!) are available here with his permission. Please click on slide below to view

Screenshot 2014-12-29 19.33.36


Dose’, modes and some of the fundamentals, perspective from a proper kidney doctor!
Dr Rosie Kalsi - Specialist Registrar in ICM, Renal & GIM

Rosie’s talk built on themes that arose in the quiz and went over some of the basics with regard to the different modes of RRT used within critical care. Dose-outcome
relationships & IRRT vs. CRRT were discussed along with mechanisms of solute clearance. The basic functions of the kidney were revised, essentially to excrete nitrogenous waste but also some endocrine functions EPO & 1,25 dihydroxycholecalciferol
(calcitriol).
Classification was revised RIFLE, AKIN, KDIGO
As was the evolving dose story - essentially 25mls/kg/hr exchange is likely better but with the appreciation that ICU patients rarely get the prescribed dosages due to
filter going down & other technical issues.

Indications for RRT on ICU were then revised

  • Oliguria < 200ml/12 hours
  • Anuria < 50 ml/12 hours
  • Hyperkalaemia > 6.5 mmol/L
  • Severe acidaemia pH < 7.0
  • Uraemia > 30 mmol/L
  • Uraemic complications (pericarditis, nausea, vomiting, poor appetite,
  • hemorrhage, lethargy, malaise, somnolence, stupor, coma, delirium, asterixis,
  • tremor, seizures)
  • Dysnatraemias > 155 or < 120 mmol/L
  • Hyper/(hypo)thermia
  • Drug overdose with dialysable drug
  • Refractory hypertension

Substances with higher degrees of protein binding and is sometimes substances with very long plasma half-lives.
• In general, the size of the molecule and the degree of protein binding determines the degree to which the substance can be removed (smaller, nonprotein
bound substances are easiest to remove).
• Techniques such as sorbent hemoperfusion may also be used.
• These substances include drugs, poisons, contrast agents, and cytokines.

ICU outcomes were then discussed especially the high rates of death when RRT is required for AKI on intensive care. AKI requiring RRT occurs in about 4-5% of ICU
admissions and is associated with worst mortality risk. The evidence for different modes was briefly reviewed:
Key points: no definitive outcome evidence has ever been found for continuous modes to be better than intermittent modes for overall mortality, or renal recovery and need for ongoing dialysis.

Pros and cons of intermittent vs. continuous therapies were discussed
The basics of how the mechanics of the filter work were reviewed which was particularly useful. How the different modes compare to the native kidney with regard to convection and diffusion capabilities was discussed. The concept of replacement fluid and effluent was explained. As was the ratio mix of pre and post blood pump fluid replacement and the reasons for adjusting this ratio. Detailed diagrams explained this nicely (See slides)

Dr Kalsi’s presentation slides are available here with her permission. Please click on slide below to view

Screenshot 2014-12-29 19.49.13


Renal ICM Updates - what’s new?
Dr Jamie Plumb - Specialty Registrar in ICM

I have also included a talk on renal updates that there was not time to give but was mostly covered by Rosie’s talk:

‘Dose’ and ‘Dose’ in Sepsis 3 big papers from 2008, 2009 & 2013
• Review of UK ICM Practice is insightful 2013 (Jones)
• Biomarkers- 2014
• Optimal timing - a few papers on this
• Modes (SLED etc.)- Great review from ‘up-to-date’
• CIN/CI-AKI

Take home message from the RENAL 2009 study Link to paper here
“In countries where continuous renal-replacement therapy is now the preferred form of renal-replacement therapy in the ICU, our study has implications for clinical practice. We found that a prescribed treatment intensity that exceeds 25 ml of effluent flow per kilogram per hour adds no significant benefit and exposes patients to the risk of hypophosphatemia.”

Take home message from IVORIE 2013: Link to paper here
“In the IVOIRE trial, there was no evidence that HVHF at 70 mL/kg/h, when compared with contemporary SVHF at 35 mL/kg/h, leads to a reduction of 28-day mortality or contributes to early improvements in haemodynamic profile or organ function. HVHF, as applied in this trial, cannot be recommended for treatment of septic shock complicated by AKI.”

Very good review of UK practice from 2013 - Jones et al: Link to paper here
“Despite its widespread use, there are several controversies about the optimal way that RRT should be delivered, particularly with respect to
modality (convective versus diffusive methods), timing of initiation and discontinuation and prescribed dose.”


Finally some recent data on prolonged (daily) intermittent renal replacement therapy" (PIRRT), very good ‘up-to-date’ article on this
‘Although not yet supported by objective data, our opinion is that PIRRT will become the dominant acute renal replacement therapy over the next 5 to 10 years”

Dr Plumb’s presentation slides are available here with his permission. Please click on slide below to view

Screenshot 2014-12-29 19.54.22

Some final thoughts
Dr Jamie Plumb - Specialty Registrar in ICM

The session closed with some quick mentions of contrast induced nephropathy (CIN), NAC, dysequilibrium syndrome and the role of bicarbonate. Slide are available to review
here

Finally, some useful resources for further reading were provided. One that is highly recommended is Dr Sara Blakeley’s Renal handbook. This is a superb resource and is available as open access (FOAMcc) (click image to download for free)


Screenshot 2014-12-29 20.13.03

Comments

Continuous RRT: What dose to prescribe?

Author: Sara Blakeley
Follow @sarablakeley


References

Ronco et al. Effects of different doses in continuous veno-venous haemofiltrationon outcomes of acute renal failure: a prospective randomised trial. Lancet 2000; 356(9223);26-30

The VA/NIH Acute Renal Failure Trial Network. Intensity of Renal Support in Critically Ill Patients with Acute Kidney Injury. NEJM 2008; 359:7-20

Renal Replacement Therapy Study Investigators. Intensity of continuous renal-replacement therapy in critically ill patients. NEJM 2009; 361(17);1627-38

Van Wert et al. High-dose renal replacement therapy for acute kidney injury: Systematic review and meta-analysis. Crit Care Med 2010;38(5):1360-9

Jum et al. Intensities of Renal Replacement Therapy in Acute Kidney Injury: A Systematic Review and Meta-Analysis. Clin J Am Soc Nephrol 2010;5(6):956-63

KDIGO Clinical Practice Guidelines

Renal Replacement Therapy in Critical Care. Guidelines from Portsmouth ICU

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