Dr.S.Venkatesan MD

Contrast induced  nephropathy (CIN)  is potentially a serious problem. The following precautions are useful in the prevention of CIN.Patients with  serum creatinine>1.5mg carry a  progressive  risk .Diabetics and elderly are more prone.Protienuria is a added risk.

• Adequate pre procedure hydration is a must . Normal saline (.45%NaCl) infused over 6 hours on the day prior  to flush the kidneys  of protiennaceous  substances.
• Low protein diet in the days prior to procedure could be useful.
• Ionic contrast to be  avoided.
• Among noninionic  low osmolar , monomeric Iohexol may be avoided . Use of isoosmolar , dimeric Iodixanal has some advantage.
• Oral antioxidant N-acetyl cysteine  600mg twice a day pre and post procedure along with .45% NaCl infusion  is found to be  useful.
• Sodium bicorbonate infusion . Three  ampuoles of normal saline .9%  in one  litre normal saline infused 3ml/kg per hour started i hour prior to procedure and continued at 1ml/kg for 6 hours post procedure has a renoprotective effect.
• There could be a role for combination of N -acetyl cystiene and sodium bicorbonate

Apart from the above measures the following general rules are vital

1. Use minimal amount of dye .<30ml. Dye volume  is more important than the type.(50 ml of isoosmolar dye is more likey to cause CIN than a 30ml of ordinary dye !)
2. Minimal views to delineate anatomy.
3. Whenever possible utilise biplane angiography.
4. Do not  give in to the  temptation of injecting a renal shot.( Although you could miss a renal artery stenosis (RAS), which is likely in these patients .Some may argue  for it ,  as  it gives us an opportunity to cure the RAS )
5. Stage the  procedure and post it on different day if intervention is required.
6. PCI for discrete straightforward lesions may be attempted
7. Avoid complex PCI in renally compromised
8. Review all the drugs for the potential renal offenders.
9. Manage the diabetes , cardiac failure meticulously
10. Have nephrologist always on a  standby mode

Post procedure follow up .

Hydration to continue

Follow up biochemistry

How often we require dialysis   in these patients  ?

It can be avoided in most if we have taken sufficient precaution. In severely compromised renal  function peri procedural dialysis is often used.

Finally , before doing a CAG in renally compromised patient always ask this  question and answer it genuinly . Is the CAG/PCI is really indicated in the given patient ?   Does it going to make a difference for the patient ‘s life ? If the answer is  – No – please avoid it !