Renal ICM Teaching 23/10/14

J Plumb

The Portsmouth Renal handbook

• Available on our very own WICS website

• I cannot recommend this highly enough

• Most questions and hence answers have been lifted directly from this book!

• I have unashamedly used it to prepare this half day!

Other bits…

• If there is time and we haven’t mentioned them already today……

• CI-AKI

• Disequilibrium Syndrome

Contrast Induced AKI CI-AKI

• True incidence is unknown

• Likely lower than we think- does it even exist? (Blakeley 2014)

• The most commonly used definition so far is a rise in serum creatinine of 44 μmol/l or a 25% increase from the baseline occurring within 48 (sometimes 72) hours from having received iodinated contrast media

• However there is no reason why a separate definition should be used!

• The creatinine usually peaks at 5 days and returns to baseline by day 10. Renal failure is normally non oliguric but some will need renal replacement therapy.

• The development of CI-AKI leads to an increased hospital stay and increased mortality; therefore efforts have focused on preventative measures.

Risk factors for CI-AKI

• As you would expect, DM, HTN,

• Nephrotoxic drugs,

• Pre-exisiting CKD,

• Liver disease,

• Dehydration (of any cause),

• Left ventricular ejection fraction < 40%

• Type of contrast used (high vol, high osmolar, arterial by far worse)

• Increasing age

Prevention

• Unclear evidence for ICU patients in the main most data is extrapolated from OP studies,

• Risk assess (do they NEED contrast?)

• Stop nephrotoxic drugs

• Choice of contrast medium. The smallest volume of a non ionic isosmolar contrast

• Hydration- we all agree on this one

Bicarb?

• Isotonic sodium bicarbonate may be better due to better volume expansion, urinary alkalinisation and reduction of free radical mediated injury.

• Trial data suggests some benefit over saline but not reaching a high grade of evidence so further studies are needed.

NAC

• Evidence is low quality- my reading around this was that it was no longer recommended but the renal handbook suggests that it is still recommended for high risk patients? Discuss

• Other therapies: Loop diuretics, mannitol and dopamine have all been used to prevent CN, however the evidence at best suggests no benefit and at worst suggests these therapies cause more harm than good.

Disequilibrium syndrome

• Has anyone seen this?

• High Urea, rapid osmotic shifts. If Urea is >25 mmol/l

• Can get cerebral oedema

• “Therefore the urea level should be brought down by no more than 1⁄3 in a 24 hour period when renal replacement therapy is first being started.”