1 / 43

Perioperative Renal Failure: Can we avoid the Gamcath  ?

Perioperative Renal Failure: Can we avoid the Gamcath  ?. Blair Schwartz January 26 th , 2010. Objectives. Review pathophysiology and diagnostic criteria for perioperative renal failure Review risk factors for the development of perioperative renal failure

willem
Download Presentation

Perioperative Renal Failure: Can we avoid the Gamcath  ?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Perioperative Renal Failure: Can we avoid the Gamcath? Blair Schwartz January 26th, 2010

  2. Objectives • Review pathophysiology and diagnostic criteria for perioperative renal failure • Review risk factors for the development of perioperative renal failure • Discuss potential methods for preventing perioperative renal failure and thus avoid the dreaded (by some) Gamcath.

  3. The definition conundrum • The major problem in “acute renal failure” research is one of lack of clear definition • Over 35 different definitions exist in the literature • Thus getting a handle on the problem is difficult

  4. Solving things the Charlton Heston way…

  5. The Acute Kidney Injury Network • “An abrupt (within 48 hours) reduction in kidney function currently defined as an absolute increase in serum creatinine of more than or equal to 0.3 mg/dl (26.4 mmol/l), a percentage increase in serum creatinine of more than or equal to 50% (1.5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour for more than six hours).” • Must be in the context of adequate hydration

  6. The new RIFLE Criteria RRT is automatically stage 3 Mehta RL, Kellum JA, Shah SV, et al. Acute Kidney Injury Network:report of an initiative to improve outcomes in acute kidney injury. Crit Care 2007 Mar 1;11(2):R31.

  7. Problems with the criteria? • Urine output not solely a reflection of renal function • Volume status • Serum Creatinine is often slow to respond and thus not an ideal marker

  8. Future fixes… • Neutrophil Gelatinase-Assoc. Lipocalin (NGAL) • Levels in blood and urine rise within a few hours after injury • Cystatin C • Absorbed by kidney, but not secreted • Rises one day before Cr • Interleukin 18 • Produced by caspase-I which is implicted in pathogenesis of ARF Have been shown to predict AKI severity in post-op hearts

  9. Prevalence of perioperative RF • Multitude of definitions makes determining the prevalence of RF very difficult • Cardiac Surgery • AKI 7.7-11.4% • CRRT <1 -5% • Gastric Bypass • AKI 8.5% • Non-Cardiac Surgery • GFR < 50 ml/min 0.8% • AAA • AKI 15-46% • OLT • AKI 48-94% • CRRT 8-17%

  10. Prevalence unclear, importance settled. • Emerging evidence that AKI, ARF, Renal failure in the perioperative period changes outcomes. • 7-10 fold increase in risk-adjusted odds of death over patients without AKI • Mortality rates at 30 days, 60 days and 1 year was increased amongst the 15,000 patients followed after non-cardiac surgery amongst those with AKI • 2.7% to 15%, 5.1-17%, 15%-31% • Similar numbers for OLT and AAA • Cardiac Surgery: • Mortality rate 0.8% without renal dysfunction • 9.5% with AKI • 44.4% with renal failure and RRT need

  11. So… • Periop RF is common • Periop RF is associated with poor outcome • Associated temporally with an identifiable event • In theory…. Perhaps a target for prevention!!!

  12. But… • To do so, must be able to identify those at risk and/or risk factors for periop AKI • Have a feasible strategy • And then question as to whether AKI is the cause of the morbidity/mortality or the result?

  13. Assuming we can intervene… • Can analyze risk factors: • Preoperative factors • Intraoperative factors • Postoperative factors

  14. Preoperative Risk Factors • Kheterpal • 15,000 patients with normal preoperative RF undergoing non-cardiac surgery • identified the following independent risk factors for post-op RF: • Age • Emergency Surgery • BMI > 33 • Peripheral Vascular Occlusive Disease • COPD needing bronchodilator therapy

  15. Always with the hearts

  16. Summary… • From a patient perspective, the more comorbid illness associated with RF, the more RF postop • Thus we are ALREADY getting the information we need to prognosticate • In fact an RCRI >2 has been shown to be an independent predictor • Granted, Creat >177 and DM on insulin are included in the RCRI and are known ARF RF

  17. More preop things… • “Maintenance of adequate intravascular volume” • Perhaps one of the most loaded statements in all of medicine, but certainly important • Uncorrected hypovolemia can well lead to pre-renal AKI and in the context of further perioperative stress can lead to ischemic ATN • Thus an important part of the perioperative consultation • Particularly in emergent surgery, and definitely in hip fractures!!!!

  18. Volume et al… • Unclear what the best way to determine this is… • History • Physical exam • Swann? • All methods have their limitations, thus likely a combination of some/all of the above

  19. Peri-operative Issues • Examine for volume status • Be cognizant of NPO duration, frequent cancellations and ensure adequate maintenance fluids • What to do with diuretics, both pre-op, day of the OR… • Be alert to patients at risk and the routine prescription of NSAIDs with anaesthesia protocols • Keep a keen eye as well for all other nephrotoxins

  20. Fluid of choice? • The never ending crystalloid/colloid debate • Insufficient evidence to suggest one over the other • NB. Pentaspan and some other HES associated with RF (and coagulopathies) over maximum suggested doses…controversial • Will this be fixed with voluven?

  21. What about optimizing renal perfusion? • Renal perfusion autoregulates between MAP 80-160 mmHg to maintain stable GFR • Unclear what ideal MAP is to “protect” kidneys • In septic shock, 85 was NOT better than 65 • One study used doppler U/S to assess renal resistive indices to individualize MAP goals • Taking MAP from 65-75 mmHg led to increased UO an decreased resistance • No improvement when MAP from 75-85 mmHg

  22. Perfusion Issues • What is the optimal perfusion pressure in people with chronic HTN? RAS? • What to do with BP Meds: • HCTZ… addressed earlier • ACE/ARB/DRI… • Alters renal regulation • Associated with post-induction hypotension • No clear renal outcome data periop • Individualize periop RAAS agent management

  23. What about the Surgeons? • Cardiac Surgery (yes again…) • Duration of pump run • Risk increases over 100 minutes • ? Lack of pulsatile flow as aetiology • More data to come from long term analysis of continuous flow HeartMate 2 VADS • What about the role of Off-pump bypass • Lower incidence of AKI (and other CPB complications) • But…recent concerns about cardiac outcomes

  24. Blame the Surgeons • AAA • Related to duration of cross-clamp • Can be technical as well if they “bag” the renals • Suggestion of improved outcomes with endovascular repairs • Thus to be considered when risk stratifying preoperatively

  25. Can we blame general surgeons too? • Laparoscopy • Renal blood flow and function are reduced during pneumoperitoneum • As intrabdominal pressure increases, U/O decreases…. • Form of abdominal compartment syndrome • Likely safe under 15 • Case reports of renal failure post-laparoscopy exist • ? Role of hypovolemia as contributor • Can consider gasless laparoscopy in those at high risk!!! • ?RAS

  26. Yet another hit on transfusion • Independently associated with increased risk of post-op AKI in OLT patients. • As always… • ? Cause/effect

  27. So now what? • If we identify patients at risk… • And mitigate all that is controllable… • Is there any targeted therapies we can try to decrease the risk of periop RF?

  28. Good old fashioned Lasix • “inhibition of renal tubular oxygen consumption” • Animal models…?mechanism • Would it prevent ischemia during times of low delivery? • Like cross clamping! • Has NOT been shown to decrease perioperative AKI • Will increase urine output, convert to non-oliguric, which may be useful • But no change in hard endpoints

  29. “Renal Dose” Dopamine • Has been extensively studied… • Will increase urine output; which may not be a bad thing • Has numerous side effects • Does NOT protect patients from AKI

  30. What if we’re NOT afraid of the Gamcath? • Prophylactic Dialysis • Has been evaluated in extremely high risk surgeries; case control • OLT in patients with borderline renal function preop • Did not decrease rates of perioperative AKI • But useful to manage complications like hypervolemia, acidosis and hyperkalemia

  31. Is there any hope?

  32. Fenoldopam!!! • Dopamine-I receptor agonist approved for the treatment of hypertensive emergencies

  33. Background • Selective short-acting Dopamine-1 agonist • Smooth-muscle relaxation • Renal vasodilatation • Tubular sodium reabsorption • Data existing is all over the map • Previous large study was negative, but control group was dopamine! Also used lower dose. • Aim is confirm effectiveness of fenoldopam 0.1 g/kg/min for preserving RF in patients undergoing elective heart surgery who are at high risk for postop AKI

  34. Methods • Inclusion Criteria: • ONE of the following RF (and elective heart surgery) • Creat >1.5 mg/dl (132 mol/L) • Age >70 • DM on insulin • Repeat sternotomy • Exclusion Criteria: • <18 y/o • Preop dialysis or inotropes • Allergy to fenoldopam

  35. Methods • Usual cardiac surgery technique was used • No aprotinin given • Standard criteria to give vasopressors, fluid and inotropes defined • Computer generated randomization to fenoldopam vs placebo, investigators, clinicians and patients blinded to assignment. • Primary Endpoint: AKI, post-op creat > 2 mg/dl (177 mol/L) on day 1 or 2

  36. Results

  37. Results

  38. Results • CRRT started in 0/95 patients in the fenoldopam group, compared to 8/98 (8.2%) in placebo • So maybe we can avoid the Gamcath after all?

  39. Other stuff? • Anaritide • recombinant human atrial natriuretic peptide, • an infusion of 50 ng/kg/min decreased the probability of dialysis in a study of postcardiac surgical heart failure patients with AKI.

  40. Take Home Messages • Periop AKI is common and serious • Judicious management of volume and pressure is important • Be aware of high risk patients and try to avoid doing silly things to them • Await further studies on Fenoldopam and anaritide.

  41. Questions?

  42. References • Zanardo G, Michielon P, Paccagnella A, et al. Acute renal failure in the patient undergoing cardiac operation. Prevalence, mortality rate, and main risk factors. J Thorac Cardiovasc Surg. 1994;107:1489–1495. • Thakar CV, Arrigain S, Worley S, et al. A clinical score to predict acute renal failure after cardiac surgery. J Am Soc Nephrol. 2005;16:162–168. • Kheterpal S, Tremper KK, Englesbe MJ, et al. Predictors of postoperative acute renal failure after noncardiac surgery in patients with previously normal renal function. Anesthesiology. 2007;107:892–902. • Thakar CV, Kharat V, Blanck S, et al. Acute kidney injury after gastric bypass surgery. Clin J Am Soc Nephrol. 2007;2:426–430. • Barratt J, Parajasingam R, Sayers RD, et al. Outcome of acute renal failure following surgical repair of ruptured abdominal aortic aneurysms. Eur J Vasc Endovasc Surg. 2000;20:163–168. • Sward K, Valsson F, Odencrants P et al. Recombinant human atrial natriuretic peptide in ischemic acute renal failure: a randomized placebo-controlled trial. Critical Care Medicine 2004 Jun; 32(6): 1310–1315. • Kellum JA & Decker M. Use of dopamine in acute renal failure: a meta-analysis. Critical Care Medicin 2001 Aug; 29(8): 1526–1531 • Deruddre S, Cheisson G, Mazoit JX et al. Renal arterial resistance in septic shock: effects of increasing mean arterial pressure with norepinephrine on the renal resistive index assessed with Doppler ultrasonography. Intensive Care Medicine 2007 May 8

More Related