ICU Nephrology - Nephrology Symposium - Aug 2014


Published on

by Wael F M Hussein
Nephrology Fellow
Palo Alto, CA

Published in: Education

ICU Nephrology - Nephrology Symposium - Aug 2014

  2. 2. Overview Acute kidney injury in the ICU ◦ Epidemiology ◦ Causes and investigations ◦ Fluid management ◦ Sepsis ◦ Acute lung injury and adult respiratory distress syndrome ◦ Conservative management of AKI ◦ Renal replacement therapy: indications, modalities, timing
  3. 3. AKI in the ICU AKI affects 5 to 7% of all hospitalized patients Mandelbaum et al. Outcome of Critically ill Patients with Acute Kidney Injury using the AKIN Criteria. Crit Care Med. Dec 2011; 39(12): 2659–2664 ◦ Using database records to find patients with serum creatinine rises (>0.3mg/dl) and/or oliguria (<0.5/ml/kg/h) for a period of 6 hours ◦ 7 ICUs
  4. 4. 14,524 patients met the inclusion criteria. 57% developed AKI during their ICU stay. In-hospital mortality rates were: 13.9%, 16.4%, 33.8% for AKI 1, 2 and 3 respectively compared to only 6.2% in patients without AKI (p<0.0001). After adjusting for multiple covariates, AKI was associated with increased hospital mortality (OR 1.4 and 1.3 for AKI1 and AKI2 and 2.5 for AKI3; p<0.0001).
  5. 5. Kaplan-Meier survival plot for 28 day in-hospital mortality divided by AKI stages
  6. 6. Acute Kidney Injury in the ICU Causes Workup ◦ Biomarkers ◦ Ultrasonography Management
  7. 7. Identifying AKI Definitions are not necessarily helpful in acute management ◦ Baseline creatinine ◦ Pre vs intrinsic renal disease ◦ Dilutional effect of fluid resuscitation Do not rely on formulas to estimate the GFR ◦ Formulas developed for CKD ◦ S Cr not in steady state
  8. 8. Relationship between GFR and S Cr in AKI
  9. 9. What is the GFR in a patient with anuria and a serum Cr of.. ◦ 1 mg/dL? ◦ 2 mg/dL? ◦ 4 mg/dL? ◦ 12 mg/dL?
  10. 10. Workup Baseline HPI PMH, FH, Social Hx Medications Clinical examination Events since onset of presenting illness, including management in the emergency room Vitals flow-sheet Laboratory tests Radiology tests
  11. 11.
  12. 12. ACEI/ARB therapy
  13. 13. Radiology CXR Any contrast studies Renal US
  14. 14. The renal ultrasound Size and structure Cortico-medullary differentiation Cortical thickness Presence of hyrdronephrosis Arterial and venous systems
  15. 15. Iodine contrast Outpatient versus inpatient setting Definitions used for contrast-induced AKI Is it the contrast or it what is going on with the patient? To contrast or not to contrast? What about gadolinium for MRI?
  16. 16. Chertow et al. "Renalism": inappropriately low rates of coronary angiography in elderly individuals with renal insufficiency. J Am Soc Nephrol. 2004 Sep;15(9):2462-8. Ongoing study: ◦ Weisbord et al. Prevention of contrast-induced AKI: a review of published trials and the design of the prevention of serious adverse events following angiography (PRESERVE) trial. Clin J Am Soc Nephrol. 2013 Sep;8(9):1618-31. Current recommendations ◦ NAC ◦ Hydration ◦ No value for post-exposure dialysis ‘to remove the contrast material’
  17. 17. Shock SBP<90, MAP <60, or relative hypotension resulting in inadequate end-organ perfusion Causes: hypovolemic, distributive, cardiogenic, obstructive Diagnosis: echo, ◦ Invasive monitoring: CVP, ScVO2, Pulmonary artery catheter, Cardiac output monitoring
  18. 18. Treatment of shock Treat the underlying cause Volume resuscitation Vasoactive agents Early goal-directed therapy for sepsis Corticosteroids Supportive care
  19. 19. Hemodynamic management Volume resuscitation ◦ Dehydration, Sepsis, Trauma, Burns, Contrast To ensure proper tissue perfusion Through careful balance between cardiac output and PVR Management through ◦ Fluids ◦ Diuretics ◦ Inotropic support ◦ Vasopressors Markers ◦ CVP ◦ MAP
  20. 20. MAP can be improved by vasopressors, but overuse of vasopressors can have a detrimental effect on tissue perfusion Precautions about the use of CVP IVC diameter Fluid boluses/ challenge FREQUENT ASSESSMENT Pre vs intrinsic renal failure secondary to reduced perfusion
  21. 21. Fluid management Early and appropriate fluid management to improve tissue perfusion and prevent or minimize AKI Fluid overload is associated with increased mortality and AKI
  22. 22. Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med 2001;345:1368-1377 ◦ About 130 patients in each arm ◦ EGDT with crystalloids, vasopressors and red blood cells according to a specific protocol ◦ VS standard therapy ◦ Mortality 30.5% vs 46.5% ◦ First 6 hours: 4,981 ml vs 3,499 ml. ◦ Over 72 hours: both groups received over 13 L ◦ Incidence of AKI not reported Newer trials: ProCESS, ARISE (Australia), PROMISE (UK) ProCESS: NEJM May 2014. 3 groups: EGDT, protocol-based standard tx, usual care) ◦ 2.8 L vs 3.3 L vs 2.3 L ◦ AKI was higher in group 2 (6%) compared to the other groups (about 3% each).
  23. 23. Type of fluids Crystalloids vs colloids (12, 13) ◦ Pulmonary and peripheral edema ◦ Hypoalbuminemia Colloids are associated with increased risk of kidney failure (14) Starch (HES) is associated with harm Albumin: SAFE study, 4% albumin vs NS. ◦ No difference in mortality, new organ dysfunction, duration of RRT Hyperoncotic albumin (20-25%), may have a protective effect on renal function (OR 0.24; 95% CI: 0.12 – 0.48) and mortality (OR 0.52, 95%CI 0.28 to 0.95) [included a large proportion of patients with cirrhosis]
  24. 24. Late fluid management After initial patient stabilization FACTT ◦ Negative effect of fluid accumulation on pulmonary function ◦ Failed to show improved survival with conservative therapy Several smaller studies showed improved outcomes with even to negative balance in late fluid management AKI patients ◦ Subsequent analysis of FACTT ◦ RENAL trial ◦ PICARD
  25. 25. Fluid management - Summary Early resuscitation Late even balance when possible – based on observational studies only, RCTs are required
  26. 26. Diuretics Oliguric vs non-oliguric renal failure Fluid accumulation Animal studies ◦ Na-K-2Cl cotransporter ◦ Prostaglandins
  27. 27. Diuretics Prevention of AKI ◦ Furosemide does not prevent AKI – meta-analysis Treatment of AKI ◦ Diuretics should not be used to treat AKI. ◦ Diuretics can be used to help with fluid management in patients with AKI FACTT: fluid balance, diuretics, mortality ◦ In patients on RRT, furosemide did not affect recovery despite increasing urine volume Ongoing treatments: SPARK , “The Effect of Loop Diuretics on Severity and Outcome of Acute Kidney Injury”
  28. 28. Furosemide to prevent or treat AKI Ho, Sheirdan. Meta-analysis of frusemide to prevent or treat acute renal failure. BMJ 2006, 333(7565):420 9 RCTs ◦ in-hospital mortality (RR 1.11, 95% CI 0.92 to 1.33), ◦ risk for requiring RRT (0.99, 0.80 to 1.22), ◦ number of dialysis sessions required ◦ proportion of patients with persistent oliguria ◦ mortality (relative risk ratio 2.10, 95% confidence interval 0.67 to 6.63) ◦ risk for requiring dialysis (4.12, 0.46 to 37.2). ◦ increased risk of temporary deafness and tinnitus in patients treated with high doses of frusemide (relative risk 3.97, 95% confidence interval 1.00 to 15.78)
  29. 29. To diurese or not to diurese Decreased urine output – a marker of AKI But to treat, you need to answer this question: what is the volume status? More specifically: what is the effective intravascular volume status?
  30. 30. Pressors/ Inotropes Norepinephrine is the preferred agent If cardiac contractility is impaired, add an inotropic agent ◦ Dobutamine + norepinephrine OR ◦ Epinephrine as both an inotrope and a vaso-pressor +/- vasopressin
  31. 31. Low-dose dopamine Bellomo et al. Lancet 2000 356(9248):2139-43. Multicentre, randomised, double-blind, placebo-controlled study 328 patients, 23 ICUs ◦ Low dose dopamine (2g/Kg/min) or placebo No clinically significant protection from renal dysfunction ◦ Peak S Cr ◦ Increase in S Cr from baseline ◦ Number of patients with S Cr > 300 mol/L (3.4 mg/dL), or who required RRT ◦ Duration of ICU stay or hospital stay ◦ Number of patients who died
  32. 32. ALI/ Adult RDS Acute onset (<7 days) of: ◦ Hypoxemia ◦ Bilateral infiltrates on CXR ◦ No evidence of left atrial hypertension Mortality: 25 to 40% Treatment: ◦ Lung protection: low tidal volume ventilation ◦ Fluid conservative management ◦ Other measures
  33. 33. ALI – Acute Lung Injury Low volume low pressure ventilation Conservative fluid therapy when possible – CVP < 4 cmH2O with fluid restriction and/or diuretics
  34. 34. Ventilator-associated pneumonia Clinical suspicion: secretions, fever, high WCC, increased ventilator support Culture Antimicrobial cover
  35. 35. Catheter-related infections Types of catheters Colonization vs infection Exit-site/ tunnel/ blood-stream infections Subclavian catheters Internal jugular vs femoral Diagnosis: ◦ Time to positivity test ◦ Quantitative blood cultures ◦ Catheter tip culture Tx: ◦ Antimicrobial therapy ◦ Catheter removal
  36. 36. Management of Sepsis Early recognition Volume resuscitation Early and appropriate antibiotics Lung-protective strategies Management of shock Steroids in septic shock Kidney support Glycemic control Adjunctive therapies Venkataraman and Kellum. Sepsis: Update in the Management. ACKD 20 (1) – Jan 2013
  37. 37. Septic shock Sepsis is the most common etiology of AKI Rapid management is important. Start while taking history and performing examination. Send your labs early, including cultures Administer antibiotics early Measure serum lactate Access, IV fluids Hemodynamic monitoring Some of the targets of EDGE: CVP 8-12 cmH2O, MAP 65 mmHg, UOP >=0.5 ml/kg/hr CVP can be affected by several factors: Tricuspid valve disease, Pulm Htn, ventilation, pericardial or intra-abdominal pressure MAP: Pre-morbid conditions: eg, cirrhotic patients vs hypertensive patients
  38. 38. Steroids in septic shock Relative adrenal insufficiency: low response and increased resistance Suspect the condition in patients poorly responding to fluid resuscitation and pressor support Hydrocortinsone 50 mg 6 hourly
  39. 39. Kidney support in Septic Shock Maintain adequate hydration and organ perfusion ◦ MAP ◦ CVP No role for low dose dopamine in kidney protection Diuretics only as part of fluid management RRT ◦ Indications. Beware of potential side effects and complications, as well as end-of-life issues ◦ Timing ◦ Modality
  40. 40. Conservative management of AKI Stop insult Correct volume status and BP Avoid precipitating the need for RRT ◦ Be smart with fluid management ◦ Be careful with K Avoid nephrotoxic agents Correction of hyperkalemia Correction of acidosis Be vigilant and be ready for when RRT can be utilized ◦ Discuss whether dialysis is an option that is consistent with goals of care
  41. 41. Hyperkalemia: ◦ Restriction of potassium in the diet, avoidance of potassium-containing drugs and fluids ◦ Can increase rapidly in oliguria, rhabdomyolysis, tissue breakdown such as ischemia or tumor lysis. ◦ Insulin, D50 (act right away), sodium bicarbonate (act in 3-5hrs), and calcium gluconate ◦ While the above shift potassium into cells, diuretics and kayexalate are needed to remove potassium out of the body Supportive Treatment Slide from Kevin Erickson, MD, Stanford Hospital
  42. 42. Acidosis: ◦ Usually does not require treatment unless HCO3<15. ◦ Can give bicarbonate. ◦ 1 amp = 50meq sodium bicarbonate. Therefore, 3amps is isotonic (150meq) ◦ If pushing bicarbonate watch for hypernatremia Supportive Treatment Slide from Kevin Erickson, MD, Stanford Hospital
  43. 43. Supportive Treatment Nutritional Support: ◦ If not catabolic, restrict protein to 0.8g/kg. If catabolic may receive up to 1.4g/kg ◦ Caloric intake between 25-35 Kcal/Kg ◦ Restrict phosphorus < 1gm/day, salt (2gm/day), and potassium (2gm/day) Anemia: ◦ Transfusions, and EPO if renal recovery is delayed of if there is a chronic component Slide from Kevin Erickson, MD, Stanford Hospital
  44. 44. Drug dosing: ◦ Antibiotics ◦ Atenolol ◦ Digoxin ◦ Lithium (antipsychotics) ◦ Allopurinol/colchicine ◦ Statins – increased risk of rhabdomyolysis Discontinue: Morphine, lovenox. Hold ACE/ARB, K sparing diuretics, NSAIDS, oral hypoglycemics, metformin. Supportive Treatment Slide from Kevin Erickson, MD, Stanford Hospital
  45. 45. Early versus late initiation of dialysis
  46. 46. Timing of initiation of RRT No clear evidence for benefit with early vs late initiation Clinical judgment is necessary ◦ Severity of disease ◦ Prognosis ◦ Effect of ongoing management ◦ Risks associated with RRT
  47. 47. J Korean Soc Pediatr Nephrol. 2009 Oct;13(2):118-129.
  48. 48. Modalities of RRT in the ICU Hemodialysis ◦ Intermittent HD ◦ Standard HD ◦ SLED Continuous modalities ◦ CVVHDF ◦ CVVHD ◦ Ultrafiltration
  49. 49. Modality choice for RRT Vinsonneau et al. Continuous venovenous hemodiafiltration versus intermittent hemodialysis for acute renal failure in patients with multiple-organ dysfunction syndrome: A muticentre randomized trial. The LANCET, 2006, 368 (9533): 379-385 21 centers in France, 360 patients 60-day survival rates similar: 32% vs 33%
  50. 50. Anticoagulation for RRT Heparin ◦ Systemic anticoagulation ◦ Titrated to APTT Citrate ◦ Regional anticoagulation ◦ Requires regular monitoring of ◦ Total Ca ◦ Ionized Ca ◦ Acid-base status ◦ Be cautious in cases of severe liver disease
  51. 51. Management of Patients on Dialysis Discuss goals of care Overall mortality of patients with AKI in the ICU is approximately 50% and has changed little over the past 4 decades. 60-90% of patients with septic-related AKI die. Slide from Kevin Erickson, MD, Stanford Hospital
  52. 52. Issues not discussed Drug dosing Management of intoxication Other causes of AKI in the ICU ◦ Cardio-renal and reno-cardiac disease ◦ AKI in liver disease ◦ Athero-embolic renal disease ◦ Abdominal compartment syndrome ◦ Pigment-induced AKI ◦ Many other causes of AKI including PIGN, HUS, TTP Nutritional support in AKI Anemia management Management of patients with ESKD Peri-operative management of kidney disease Management of acid-base disturbances and electrolytes
  53. 53. Take home messages AKI is common in critically ill patients and is associated with poor outcomes Prompt recognition and management are essential Identify the cause and stop the insult early Crystalloids or diuretics are required for fluid management according to the volume status Be alert to when RRT is required. Early start is not associated with better outcomes, but don’t hold the therapy when required Modality choice may be influenced by availability and logistics