1. Dialysis in the Critically Ill
Fellow’s conference
Cheryl Pirozzi, MD
February 15, 2012

2. Outline AKI in the ICU Principles of RRT Modes of RRT
Indications for RRT
Optimal timing: When to start and stop
Optimal modality: When to use what
Optimal dosing
RRT in specific clinical situations
Conclusions

3. AKI in the ICU AKI is common in the ICU
Depending on definition of AKI, up to 50-60% of patients in the ICU
Up to 70% of these will require RRT
Independent risk factor for mortality, % mortality in critically ill
who were either treated with RRT or fulfilled at least one predefined criteria for AKI, either oliguria (urine output < 200 mL/12 hr) or marked azotemia (blood urea nitrogen [BUN] level > 30 mmol/L). The data were collected at 54 hospitals in 23 countries. Of 29,269 critically ill patients admitted during the study period, 1,738 (5.7%) had AKI during their ICU stay, including 1,260 (4.3%) who were treated with RRT. Overall hospital mortality was 60.3%. The most common contributing factor to AKI was septic shock (47.5%). Approximately 30% of patients had preadmission renal dysfunction. At hospital discharge, 86.2% survivors were independent from dialysis. Independent risk factors for hospital mortality included the use of vasopressors, mechanical ventilation, septic shock, cardiogenic shock, and hepatorenal syndrome.
AKI in critically ill associated with % mortality
Rondon-Berrios. Curr Opin Nephrol Hypertens Mar;16(2):64-70.
Foot. Current Anaesthesia and Critical Care 2005; 16:
Miller's Anesthesia, 7th ed. 2009

4. AKI in the ICU
Treatment of acute kidney injury (AKI) is principally supportive -- renal replacement therapy (RRT) indicated in patients with severe kidney injury.
Goal: optimization of fluid & electrolyte balance
Multiple modalities of RRT :
Intermittent hemodialysis (IHD),
continuous renal replacement therapies (CRRTs)
hybrid therapies, ie sustained low-efficiency dialysis (SLED)
Foot. Current Anaesthesia and Critical Care 2005; 16:

5. Principles of dialysis
Dialysis = diffusion = passive movement of solutes across a semi-permeable membrane down concentration gradient
Good for small molecules
(Ultra)filtration = convection = solute + fluid removal across semi-permeable membrane down a pressure gradient (solvent drag)
Better for removal of fluid and medium-size molecules
Dialysis is a process which uses diffusion which is…
Filtration is a process using convection which is..
Faber. Nursing in Critical Care 2009; 14: 4
Foot. Current Anaesthesia and Critical Care 2005; 16:

6. Principles of dialysis
Hemodialysis = solute passively diffuses down concentration gradient
Dialysate flows countercurrent to blood flow.
Urea, creatinine, K move from blood to dialysate
Ca and bicarb move from dialysate to blood.
Hemofiltration: uses hydrostatic pressure gradient to induce filtration / convection plasma water + solutes across membrane.
Hemodiafiltration: combination of dialysis and filtration.
Convective transport of small and middle molecular weight solutes in same direction as water. Usually requires substitution fluid to prevent excess fluid removal.
Although the use of
pump-driven venovenous circuits increases the technical
complexity of therapy, the elimination of the hazards of
prolonged arterial cannulation and the provision of higher
solute clearances make these the preferred modes of
therapy [28]. Theoretically, convective therapies (hemofiltration)
provide greater clearance of higher molecular
weight solutes than diffusive therapies (hemodialysis);
however, no studies have demonstrated an association
between the mechanism of solute transport and clinical
outcomes.
Miller's Anesthesia, 7th ed. 2009
Foot. Current Anaesthesia and Critical Care 2005; 16:

7. Modality of RRT Intermittent hemodialysis (IHD)
Continuous renal replacement therapy (CRRT)
Peritoneal dialysis
Hybrid therapies, like SLEDD

8. Intermittent hemodialysis (IHD)
Oldest and most common technique
Primarily diffusive treatment: blood and dialysate are circulated in countercurrent manner
Also some fluid removal by ultrafiltration due to pressure driving through circuit
Best for removal of small molecules
typically performed 4 hours 3x/wk or daily
? The UF rate is equal to the scheduled weight loss.
Foot. Current Anaesthesia and Critical Care 2005; 16:
Miller's Anesthesia, 7th ed. 2009

9. Continuous RRT Introduced in 1980s
involve either dialysis (diffusion-based solute removal) or filtration (convection-based solute and water removal) treatments in a continuous mode with slower rate of solute or fluid removal
CRRT includes continuous hemofiltration, hemodialysis and hemodiafiltration, all of which can be performed using arteriovenous or venovenous extracorporeal circuits.
Although the use of
pump-driven venovenous circuits increases the technical
complexity of therapy, the elimination of the hazards of
prolonged arterial cannulation and the provision of higher
solute clearances make these the preferred modes of
therapy [28]. Theoretically, convective therapies (hemofiltration)
provide greater clearance of higher molecular
weight solutes than diffusive therapies (hemodialysis);
however, no studies have demonstrated an association
between the mechanism of solute transport and clinical
outcomes.

11. Continuous RRT
Continuous venovenous hemofiltration (CVVH): Uses blood pump to remove fluids/solutes by convection
Continuous venovenous hemodialysis (CVVHD): Uses pump + dialysate run at low flow rate countercurrent to blood flow
Slower fluid removal but greater solute removal
Continuous venovenous hemodiafiltration (CVVHDF): combines diffusion for small solute removal + convection for large solutes
Large volume filtered fluid → Requires replacement fluid
Most commonly used modality at the U
Although the use of
pump-driven venovenous circuits increases the technical
complexity of therapy, the elimination of the hazards of
prolonged arterial cannulation and the provision of higher
solute clearances make these the preferred modes of
therapy [28]. Theoretically, convective therapies (hemofiltration)
provide greater clearance of higher molecular
weight solutes than diffusive therapies (hemodialysis);
however, no studies have demonstrated an association
between the mechanism of solute transport and clinical
outcomes.
Downsides: requires arterial puncture (risk embolization)

12. Continuous RRT
Arteriovenous versions (CAVH, CAVHD and CAVHDF) are similar to venovenous except use AV access and systemic BP to run and blood pump not required.
Downsides: requires arterial cannulation (+ venous)
Unreliable flow in pts with ↓ BP or severe PVD
Requires more anticoagulation
VV preferred due to lower risk, only one dual lumen catheter, and faster/more reliable flow
Although the use of
pump-driven venovenous circuits increases the technical
complexity of therapy, the elimination of the hazards of
prolonged arterial cannulation and the provision of higher
solute clearances make these the preferred modes of
therapy [28]. Theoretically, convective therapies (hemofiltration)
provide greater clearance of higher molecular
weight solutes than diffusive therapies (hemodialysis);
however, no studies have demonstrated an association
between the mechanism of solute transport and clinical
outcomes.
Downsides: requires arterial puncture (risk embolization)

13. Slow continuous ultrafiltration (SCUF):
used for fluid removal in overloaded CHF patients
blood is driven through a highly permeable filter in a venovenous mode to primarily remove water, not solute.
The ultrafiltrate produced during membrane transit is not replaced so it corresponds to the fluid loss.
Miller's Anesthesia, 7th ed. 2009

14. Peritoneal dialysis Least useful form of CRRT in the ICU
diffusive treatment: blood in capillaries of peritoneal membrane exposed to dialysate in abdomen
continuous or intermittent
Inefficient solute/volume clearance if unstable or poor intestinal blood flow
Can’t use if intraabdominal pathology- risk of peritonitis
Respiratory burden
Only two RCTs comparing to hemodialysis in AKI: found inferior or no difference
Respiratory burden due to restriction/decreased diaphragmatic excursion
Vanholder. Critical Care 2011;15:204
Foot. Current Anaesthesia and Critical Care 2005; 16:

15. Sustained low-efficiency daily dialysis (SLEDD)
AKA Extended daily dialysis (EDD) or slow continuous dialysis (SCD)
Hybrid therapy: IRRT at lower blood and dialysate flows for prolonged times (Usually ≥ 5 hrs)
Uses conventional dialysis machines
Flexibility of duration and intensity
Major advantages: flexibility, reduced costs, low or absent anticoagulation
Used at IMC but not U due to tech/nurse training
Also called prolonged IRRT 15

16. Anticoagulation
CRRT requires continuous anticoagulation to prevent clotting in the CRRT circuit
Tricky bcs ICU pts often at increased risk of bleeding and hypercoagulable
Many options:
Systemic anticoagulation with heparin (mst common), LMWH, heparinoids, thrombin antagonists
Regional citrate anticoagulation (preferred)
Other regional anticoagulation ie heparin/protamine
RCA preferred at the U
Davenport. NDT Plus (2009) 2: 439–447

17. Regional citrate anticoagulation
Citrate infused into the blood at the start of the circuit
provides anticoagulation by chelating iCa++
Requires systemic Ca infusion to replace Ca lost with citrate
target extracorporeal blood citrate 4–6 mmol/l, pre-filter iCa++ <0.35 mmol/l
Citrate chelates calcium, and
at a concentration of 4–6 mmol/l with an ionized calcium
of <0.2 mmol/l prevents activation of both coagulation
cascades and platelets
As citrate chelates calcium, it may help
reduce some of the inflammatory reactions that occur by
reducing leucocyte and monocyte activation during passage
through the extracorporeal circuit [
Davenport. NDT Plus (2009) 2: 439–447

18. Regional citrate anticoagulation
Advantages of RCA for CRRT:
avoids systemic anticoagulation (lower bleeding risk) and heparin risks (HIT)
act as a buffer by conversion through to bicarbonate
Disadvantages:
potential metabolic complications: metabolic acidosis/alkalosis, hypoCa, HyperNa, hypoMag
complex protocols-- q6h monitoring of Na, K, Cl, iCa++, Mg, ABG, AG
More expensive
total systemic serum calcium.
Patients can become alkalotic due to the metabolism
of an increasing citrate load returning to the patient, but
also acidotic if citrate cannot be readily metabolized, or
the amount of citrate infused is too low. In addition, this
may be compounded by nursing and/or fluid composition
errors. However, by carefully monitoring ionized and total
calcium, appropriate adjustments can be made to dialysate
and/or replacement fluid rates and citrate and/or calcium infusion
rates, to achieve acid–base targets. Although citrate
is predominantly hepatically metabolized, many patients
with liver disease, even those with cirrhosis, can often adequately
metabolize the citrate load
Davenport. NDT Plus (2009) 2: 439–447

19. Indications for RRT
Acute management of life-threatening complications of AKI:
A: Metabolic acidosis (pH less than 7.1)
E: Electrolytes -- Hyperkalemia (K >6.5 meq/L) or rapidly rising K)
I: Ingestion -- Certain alcohol and drug intoxications
O: Refractory fluid overload
U: Uremia, ie. pericarditis, neuropathy, decline in mental status

20. Timing of initiation of RRT
Unclear if earlier RRT is better
Theoretical benefits: may attenuate organ injury from acidemia, uremia, fluid overload, and systemic inflammation
Several non-randomized studies have reported improved outcomes (incl survival), associated with early RRT
One RCT: Bouman Crit Care Med. 2002;30(10):2205
106 ICU pts with UOP < 30 x 6 hrs and CrCl <20
assigned to early (≤ 12 hrs) high- or low- volume CVVH, vs late (BUN 40 mmol/L, K 6.5 mmol/L or severe pulmonary edema) low-volume CVVH→
Survival at 28 days and recovery of renal fcn equivalent. However, underpowered
Look up definitions of “early” and “late”
Bouman 2002 Randomised Cardiac surgery/
medical
Early: CVVH RRT within 12 hours if Urine Output <30 ml/hr despite volume resuss and
Late: Urea >40 mmol/l or K >6.5 mmol/L

21. Timing of initiation of RRT
Karvellas. A comparison of early versus late initiation of renal replacement therapy in critically ill patients with acute kidney injury. Critical Care 2011, 15:R72
Meta-analysis of 15 studies
Early RRT initiation associated with ↓mortality (pooled OR 0.45)
However, significant heterogeneity and bias
Some studies showed greater renal recovery, ↓ duration RRT and ICU length of stay
Meta-analysis of 15 studies of early vs late initiation of RRT in AKI in critically ill
(2 randomised, 4 prospective cohort, 9 retrospective cohort
No consistent definition of “early” or late- mostly retrospective based on high or low BUN or Rifle Criteria

22. Timing of initiation of RRT
Earlier initiation of RRT in critically ill patients with AKI may have a beneficial impact on survival and outcomes but data is insufficient
Many recommend initiation of RRT prior to the development of advanced uremic symptoms, or when the BUN reaches mg/dL
No known threshold of fluid overload for initiating RRT
Meta-analysis of 15 studies of early vs late initiation of RRT in AKI in critically ill
(2 randomised, 4 prospective cohort, 9 retrospective cohort
No consistent definition of “early” or late

23. Discontinuation of RRT
Until “evidence of recovery of kidney function”
Improved UOP in oliguria
Decreasing creatinine
Creatinine clearance minimum 12 mL/min, some say 20 mL/min
Likewise there is no agreed upon indication for stopping RRT, and no data to support.

24. Continuous vs intermittent dialysis
Ongoing debate
Theoretical benefits to both
At least 7 RCTs and 3 meta-analyses have not demonstrated difference in outcome
Eg Bagshaw Crit Care Med 2008, 36: : metaanalysis of 9 randomized trials: No effect on mortality (OR 0.99) or recovery to RRT independence (OR 0.76).
suggestion that continuous RRT had fewer episodes of hemodynamic instability and better control of fluid balance
May be preferable in specific subpopulations
Vanholder et al. Pro/con debate: Continuous vs intermittent dialysis for acute kidney injury. Critical Care 2011, 15:204

25. Pro-continuous RRT
? Theoretical advantage of more hemodynamic stability allowing more adequate fluid removal
Metaanalysis of 15 RCTs (Rabindranath Cochrane Rev 2007, 3): no difference between CRRT and IRRT in haemodynamic instability or hypotension / escalation of pressors, or mortality or RRT independence.
Patients on CRRT had significantly higher MAP
However most trials excluded pts with major hemodynamic issues
Some RCTs (but not all) show more negative fluid balances with CRRT vs IRRT
Vanholder et al. Critical Care 2011, 15:204

26. Pro-continuous RRT
? Better recovery of renal function due to preserved hemodynamic stability
All RCTs and meta-analyses have failed to show superiority of CRRT in progression to CKD or RRT dependence
? Improved solute removal due to longer dialysis
Studies have been inconsistent in showing improved clearance of creatinine and urea with CRRT
No evidence of improved removal of cytokines
Vanholder et al. Critical Care 2011, 15:204

27. Pro-continuous RRT
Specific patient populations who may benefit from CRRT
Hemodynamic instability
Combined acute renal and hepatic failure
Improved CV instability and intracranial pressure
Acute brain injury
Decreased cerebral edema
Vanholder et al. Critical Care 2011, 15:204

28. Pro-intermittent RRT Practicality and flexibility
Uses same machines as chronic HD
Multiple pts per day
Easier to mobilize pts
Less expensive than CRRT (by about ½)
Fewer bleeding complications
CRRT requires continuous anticoagulation
Less filter clotting
Superior solute clearance, more rapid removal of toxins (due to higher flows)
Vanholder et al. Critical Care 2011, 15:204

29. Pro-intermittent RRT
Specific patient populations benefitting from IRRT:
High bleeding risk
Ie. after recent surgery
Acute treatment of hyperkalemia, rhabdomyolysis, poisoning, tumor lysis syndrome
Vanholder et al. Critical Care 2011, 15:204

30. Is SLEDD the answer?
Hybrid therapy with flexibility of duration and intensity
SLEDD vs CRRT
Major advantages: flexibility, reduced costs, low or absent anticoagulation
Similar adequacy and hemodynamics
One small study (16 pts) showed slightly higher acidosis and lower BP (Baldwin 2007)
VA trial (Palevsky NEJM 2008) suggests similar outcomes as CRRT and IRRT.
Maybe SLEDD is the answer.
Also called prolonged IRRT
Vanholder et al. Critical Care 2011, 15:204

31. Optimal dosing Optimal intensity of RRT is controversial
VA/NIH Acute Renal Failure Trial Network. (NEJM 2008;359:7): RCT of 1124 critically ill pts with AKI and sepsis or at least one organ failure to intensive or less intensive renal-replacement therapy
Hemodynamically unstable pts received CRRT or SLEDD, stable pts IRRT
Intensive RRT= IRRT or SLEDD 6x/wk or CRRT at 35 ml/kg/hr
Less intensive RRT= IRRT or SLEDD 3x/wk or CRRT at 20 ml/kg/hr

32. Optimal dosing VA/NIH Acute Renal Failure Trial Network
No difference in mortality, recovery of kidney function, or nonrenal organ failure
VA/NIH Acute Renal Failure Trial Network. NEJM 2008;359:7

33. Optimal dosing The RENAL Replacement Therapy Study
RCT of 1508 critically ill pts to CRRT of high vs low intensity (40 vs 25 ml/kg/hr)
No difference in 90 d mortality or RRT independence
N Engl J Med Oct 22;361(17):

34. Optimal dosing Recommended dosing: IRRT: 3x/week
CRRT: delivered effluent flow rate of at least 20 mL/kg/hr
Based on those two studies, recommendations
Up To Date.com

35. The role of RRT in different clinical situations
Sepsis and MODS
Congestive heart failure
Miller's Anesthesia, 7th ed. 2009

36. RRT in sepsis/MODS
RRT has been proposed as a “Extracorporeal blood purification therapy (EBPT)” as adjuvant therapy for sepsis/MODS for removal of harmful inflammatory mediators or endotoxemia
Some support from animal models and small clinical studies
Eg cytokines can be demonstrated in dialysis effluent
Miller's Anesthesia, 7th ed. 2009
Foot. Current Anaesthesia and Critical Care 2005; 16:

37. RRT in sepsis/MODS Limited data, small studies:
Cole. Crit Care Med Jan;30(1):100-6
Phase II RCT of early CVVH x 48 h in 24 pts with septic shock/MODS
No ↓ in circulating cytokines and anaphylatoxins or organ dysfunction
8 h of high-volume haemofiltration (HVHF; 6 l/h) or 8 h of standard continuous veno-venous haemofiltration (CVVH; 1 l/h) in random order.
We measured changes in haemodynamic variables, dose of norepinephrine required to maintain a mean arterial pressure greater than 70 mmHg and plasma concentrations of complement anaphylatoxins and several cytokines. An 8-h period of HVHF was associated with a greater reduction in norepinephrine requirements than a similar period of CVVH (median reduction: 10.5 vs. 1.0 microg/min; p = 0.01; median percentage reduction: 68 vs. 7%; p = 0.02). Both therapies were associated with a temporary reduction (p < 0.01) in the plasma concentration of C3a, C5a, and interleukin 10 within 2 h of initiation. HVHF was associated with a greater reduction in the area under the curve for C3a and C5a (p < 0.01). The concentration of the measured soluble mediators in the ultrafiltrate was negligible.
CONCLUSIONS:
HVHF decreases vasopressor requirements in human septic shock and affects anaphylatoxin levels differently than standard CVVH.
Twenty-four patients with early septic shock or septic organ dysfunction.
INTERVENTIONS:
Random allocation to receive 48 hrs of isovolemic CVVH at 2 L/hr of fluid exchange or no hemofiltration.
MEASUREMENTS AND MAIN RESULTS:
We measured the plasma concentrations of complement fractions C3a and C5a, interleukins 6, 8, and 10, and tumor necrosis factor alpha at baseline and 2, 24, 26, 48, and 72 hrs. A multiple organ dysfunction score (MODS) was calculated daily for each patient until death or discharge from the intensive care unit. The concentrations of most mediators decreased between baseline and 72 hrs. Some significant falls in concentration could be identified between specific time points, but CVVH was not associated with an overall reduction in any plasma cytokine concentrations. There was also no difference between the mean cumulative MODS for control survivors (43.3 +/- 19.7) and CVVH survivors (33.2 +/- 19.0; p = .30), and no difference between the average MODS calculated for all controls (4.1 +/- 1.9) and all CVVH subjects (3.3 +/- 1.7; p = .26). CVVH did not improve oxygenation, lower the platelet count, or reduce the duration of vasopressor support and mechanical ventilation.
Early use of CVVH at 2 L/hr did not reduce the circulating concentrations of several cytokines and anaphylatoxins associated with septic shock, or the organ dysfunction that followed severe sepsis. CVVH using current technology cannot be recommended as an adjunct to the treatment of septic shock unless severe acute renal failure is present.

38. RRT in sepsis/MODS Limited data, small studies:
Boussekey et al. Intensive Care Med Sep;34(9):
Pilot RCT of 20 pts with septic shock and ARF to high volume hemofiltration [HVHF 65 ml/(kg h)] vs low volume hemofiltration [LVHF 35 ml/(kg h).
HVHF decreased vasopressor requirement and trend towards increase urine output but no effect on survival, LOS, RRT, mech ventilation
8 h of high-volume haemofiltration (HVHF; 6 l/h) or 8 h of standard continuous veno-venous haemofiltration (CVVH; 1 l/h) in random order.
We measured changes in haemodynamic variables, dose of norepinephrine required to maintain a mean arterial pressure greater than 70 mmHg and plasma concentrations of complement anaphylatoxins and several cytokines. An 8-h period of HVHF was associated with a greater reduction in norepinephrine requirements than a similar period of CVVH (median reduction: 10.5 vs. 1.0 microg/min; p = 0.01; median percentage reduction: 68 vs. 7%; p = 0.02). Both therapies were associated with a temporary reduction (p < 0.01) in the plasma concentration of C3a, C5a, and interleukin 10 within 2 h of initiation. HVHF was associated with a greater reduction in the area under the curve for C3a and C5a (p < 0.01). The concentration of the measured soluble mediators in the ultrafiltrate was negligible.
CONCLUSIONS:
HVHF decreases vasopressor requirements in human septic shock and affects anaphylatoxin levels differently than standard CVVH.

39. RRT in sepsis/MODS Overall, no good data showing improved outcomes
Insufficient evidence to support a role for RRT as adjuvant therapy for septic shock unless severe acute renal failure is present.
8 h of high-volume haemofiltration (HVHF; 6 l/h) or 8 h of standard continuous veno-venous haemofiltration (CVVH; 1 l/h) in random order.
We measured changes in haemodynamic variables, dose of norepinephrine required to maintain a mean arterial pressure greater than 70 mmHg and plasma concentrations of complement anaphylatoxins and several cytokines. An 8-h period of HVHF was associated with a greater reduction in norepinephrine requirements than a similar period of CVVH (median reduction: 10.5 vs. 1.0 microg/min; p = 0.01; median percentage reduction: 68 vs. 7%; p = 0.02). Both therapies were associated with a temporary reduction (p < 0.01) in the plasma concentration of C3a, C5a, and interleukin 10 within 2 h of initiation. HVHF was associated with a greater reduction in the area under the curve for C3a and C5a (p < 0.01). The concentration of the measured soluble mediators in the ultrafiltrate was negligible.
CONCLUSIONS:
HVHF decreases vasopressor requirements in human septic shock and affects anaphylatoxin levels differently than standard CVVH.
Twenty-four patients with early septic shock or septic organ dysfunction.
INTERVENTIONS:
Random allocation to receive 48 hrs of isovolemic CVVH at 2 L/hr of fluid exchange or no hemofiltration.
MEASUREMENTS AND MAIN RESULTS:
We measured the plasma concentrations of complement fractions C3a and C5a, interleukins 6, 8, and 10, and tumor necrosis factor alpha at baseline and 2, 24, 26, 48, and 72 hrs. A multiple organ dysfunction score (MODS) was calculated daily for each patient until death or discharge from the intensive care unit. The concentrations of most mediators decreased between baseline and 72 hrs. Some significant falls in concentration could be identified between specific time points, but CVVH was not associated with an overall reduction in any plasma cytokine concentrations. There was also no difference between the mean cumulative MODS for control survivors (43.3 +/- 19.7) and CVVH survivors (33.2 +/- 19.0; p = .30), and no difference between the average MODS calculated for all controls (4.1 +/- 1.9) and all CVVH subjects (3.3 +/- 1.7; p = .26). CVVH did not improve oxygenation, lower the platelet count, or reduce the duration of vasopressor support and mechanical ventilation.
Early use of CVVH at 2 L/hr did not reduce the circulating concentrations of several cytokines and anaphylatoxins associated with septic shock, or the organ dysfunction that followed severe sepsis. CVVH using current technology cannot be recommended as an adjunct to the treatment of septic shock unless severe acute renal failure is present.
Foot. Current Anaesthesia and Critical Care 2005; 16:

40. RRT in congestive heart failure
Slow continuous ultrafiltration (SCUF) effective for fluid removal in decompensated CHF
UNLOAD trial (UF versus intravenous diuretics for acute decompensated CHF):
RCT 200 hypervolemic CHF pts to UF or diuretics
At 48 hrs, UF associated with improved weight and fluid removal, and ↓ 90 d rehospitalization and medical visits for CHF
Costanzo et al  J Am Coll Cardiol  2007; 49:

41. Conclusions
AKI in the ICU is common and associated with high mortality
The best time to initiate and stop RRT is controversial
No good data that CRRT is better than IRRT in the ICU, except for a few specific situations
Consider CRRT if severely unstable pts, severe volume overload, combined renal/hepatic failure
IRRT best if bleeding risk or acute hyperkalemia/poisoning
SLEDD is the most flexible

42. Conclusions
More intense RRT dosing in the ICU does not improve outcome
Insufficient evidence to support a role for RRT as adjuvant therapy for septic shock unless severe acute renal failure is present
Ultrafiltration is effective for fluid removal in CHF

44. References Miller: Miller's Anesthesia, 7th ed. 2009
Uchino S, Kellum JA, Bellomo R, et al: for the Beginning and Ending Supportive Therapy for the Kidney (BEST Kidney) Investigators. Acute renal failure in critically ill patients: A multinational, multicenter study.  JAMA  2005; 294:
Bouman CS, Oudemans-Van Straaten HM, Tijssen JG, Zandstra DF, Kesecioglu J. Effects of early high-volume continuous venovenous hemofiltration on survival and recovery of renal function in intensive care patients with acute renal failure: a prospective, randomized trial. Crit Care Med. 2002;30(10):2205.
Vanholder et al. Pro/con debate: Continuous vs intermittent dialysis for acute kidney injury. Critical Care 2011, 15:204
Uchino S, Bellomo R, Morimatsu H, et al: Continuous renal replacement therapy: A worldwide practice survey: The Beginning and Ending Supportive Therapy for the Kidney (B.E.S.T. Kidney) Investigators.  Intensive Care Med  2007; 33:
Bagshaw SM, Berthiaume LR, Delaney A, Bellomo R: Continuous versus intermittent renal replacement therapy for critically ill patients with acute kidney injury: a meta-analysis. Crit Care Med 2008, 36:
Rabindranath K, Adams J, Macleod AM, Muirhead N: Intermittent versus continuous renal replacement therapy for acute renal failure in adults. Cochrane Database Syst Rev 2007, 3:CD

45. References
Palevsky PM, Zhang JH, O’Connor TZ, Chertow GM, Crowley ST, Choudhury D, Finkel K, Kellum JA, Paganini E, Schein RM, Smith MW, Swanson KM; Thompson BT, Vijayan A, Watnick S, Star RA, Peduzzi P: Intensity of renal support in critically ill patients with acute kidney injury. N Engl J Med 2008, 359:7-20.
RENAL Replacement Therapy Study Investigators, Bellomo R, Cass A, Cole L, Finfer S, Gallagher M, Lo S, McArthur C, McGuinness S, Myburgh J, Norton R, Scheinkestel C, Su S. Intensity of continuous renal-replacement therapy in critically ill patients. N Engl J Med Oct 22;361(17):
Rondon-Berrios H, Palevsky PM. Treatment of acute kidney injury: an update on the management of renal replacement therapy. Curr Opin Nephrol Hypertens Mar;16(2):64-70.
Palevsky P. Renal replacement therapy (dialysis) in acute kidney injury (acute renal failure) in adults: Indications, timing, and dialysis dose. UpToDate.com 2012
Boussekey N, Chiche A, Faure K, Devos P, Guery B, d'Escrivan T, Georges H, Leroy O. A pilot randomized study comparing high and low volume hemofiltration on vasopressor use in septic shock Intensive Care Med Sep;34(9):
Cole L, Bellomo R, Journois D, et al: High-volume hemofiltration in human septic shock.  Intensive Care Med  2001; 27:
Cole L, Bellomo R, Hart G, et al: A phase II randomized, controlled trial of continuous hemofiltration in sepsis.  Crit Care Med  2002; 30:

46. References
Costanzo MR, Guglin M, Saltzberg MT, et al: for the UNLOAD Trial Investigators: Ultrafiltration versus intravenous diuretics for patients hospitalized for acute decompensated heart failure.  J Am Coll Cardiol  2007; 49:
Ronco C, Brendolan A, Lonnemann G, et al: A pilot study of coupled plasma filtration with adsorption in septic shock.  Crit Care Med  2002; 30:
Carole L. Foot, John F. Fraser. So you need to start renal replacement therapy on your ICU patient? Current Anaesthesia & Critical Care (2005) 16, 321–329
Peter Faber and Andrew A Klein. Acute kidney injury and renal replacement therapy in the intensive care unit. Nursing in Critical Care 2009; 14: 4
Davenport A, Tolwani A. Citrate anticoagulation for continuous renal replacement therapy (CRRT) in patients with acute kidney injury admitted to the intensive care unit. NDT Plus (2009) 2: 439–447

47. Surviving sepsis 2008:
D. Renal Replacement 1. We suggest that continuous renal replacement therapies and intermittent hemodialysis are equivalent in patients with severe sepsis and acute renal failure (grade 2B). 2. We suggest the use of continuous therapies to facilitate management of fluid balance in hemodynamically unstable septic patients (grade 2D

48. AKI in the ICU
In BEST Kidney trial: multinational observational trial of 29,269 ICU patients with AKI [oliguria (UOP < 200/12h, azotemia (BUN > 30) or RRT]
5.7% had AKI during their ICU stay
4.3% treated with RRT
47.5% due to septic shock
30% had preadmission CKD
Overall hospital mortality 60.3%. Of survivors, 13.8% dialysis dependent at discharge
Independent risk factors for hospital mortality included the use of vasopressors, mechanical ventilation, septic shock, cardiogenic shock, and hepatorenal syndrome.
who were either treated with RRT or fulfilled at least one predefined criteria for AKI, either oliguria (urine output < 200 mL/12 hr) or marked azotemia (blood urea nitrogen [BUN] level > 30 mmol/L). The data were collected at 54 hospitals in 23 countries. Of 29,269 critically ill patients admitted during the study period, 1,738 (5.7%) had AKI during their ICU stay, including 1,260 (4.3%) who were treated with RRT. Overall hospital mortality was 60.3%. The most common contributing factor to AKI was septic shock (47.5%). Approximately 30% of patients had preadmission renal dysfunction. At hospital discharge, 86.2% survivors were independent from dialysis. Independent risk factors for hospital mortality included the use of vasopressors, mechanical ventilation, septic shock, cardiogenic shock, and hepatorenal syndrome.
AKI in critically ill associated with % mortality
Uchino JAMA  2005; 294:
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