Dialytic Management of AKI - Dr. Gawad

Dialytic Management of AKI
Mohammed Abdel Gawad
Nephrology Specialist
Kidney & Urology Center (KUC)
Alexandria - EGY
drgawad@gmail.com
When to Initiate?
Best Modality?
When to Stop?
What is the Dose?
The Evidence

To download the lecture please
contact me
drgawad@gmail.com
For more lectures visit
www.NephroTubeCNE.com

Dialytic Management of AKI
When to Initiate?
Best Modality?
When to Stop?
What is the Dose?
What is the Evidence?

When to initiate? Early vs Late
• More rapid metabolic/ureamic control
• More effective prevention and management of fluid
overload
• Attenuate kidney-specific and non-kidney organ injury from
acideamia, ureamia, fluid overload and systemic
inflammation
Gibney N et al. Clin J Am Soc Nephrol 2008; 3: 876–880
Clark WR et al. Blood Purif 2006; 24: 487–498
Matson J et al. Crit Care Resusc 2004; 6:209–217
Theoretical benefits of earlier initiation of RRT

What is meant by EARLY?
What is meant by LATE?
Studies aimed at determining the optimal time for starting
RRT have evaluated various arbitrary cut-offs for:
• serum creatinine
• serum urea
• urine output
• fluid balance
• time from ICU admission or duration of AKI

Serum Creatinine as a trigger for RRT

Serum Urea as a trigger for RRT

UOP as a trigger for RRT

UOP as a trigger for RRT
RCT

The optimal timing of dialysis for
AKI is not defined
• Fluid overload (refractory to medical measures)
• Hyperkalemia (refractory to medical measures)
• Sever metabolic acidosis (refractory to medical
measures)
• Signs of uremia (such as pericarditis, neuropathy, or
an otherwise unexplained decline in mental status)
• Certain alcohol and drug intoxications
Kidney International Supplements (2012) 2, 89–115

The optimal timing of dialysis for
AKI is not defined
• Fluid overload (refractory to medical measures)
• Hyperkalemia (refractory to medical measures)
• Sever metabolic acidosis (refractory to medical
measures)
• Signs of uremia (such as pericarditis, neuropathy, or
an otherwise unexplained decline in mental status)
• Certain alcohol and drug intoxications
In the
absence of
these factors
there is
generally a
tendency to
avoid dialysis
as long as
possible

• To Consider RRT:
– Oliguria: urine output <100 ml in 6h
– Potassium >6.5 mmol/L
– pH <7.2
– BUN >70 mg/dl
– Creatinine >3.5 mg/dl
– Clinically significant organ edema
RENAL, Bellomo R, Cass A, Cole L, et al. N Engl J Med 2009; 361: 1627–1638.

• To Consider RRT:
– Urea  21 mmol/L
– Volume overload
– Persistent hyperkalemia (K+ > 6.2 mEq/L or ECG changes)
– Severe metabolic acidosis (pH < 7.20)
– Uremic signs or symptoms
VA/NIH Acute Renal Failure Trial Network, Palevsky PM et al. N Engl J Med. 2008;359:7-20

Whatever criteria are used to define ‘early’ versus
‘late’ RRT,
it is apparent that what may be ‘early’ for one patient
could be ‘late’ for another patient
depending on the patient’s comorbidity and clinical
course
Macedo E, Mehta R. Semin Dial 2011; 24: 132–137

Other factors that might influence the decision of when to
start RRT are:
• the severity of the underlying disease (affecting the likelihood of
recovery of kidney function),
• the degree of dysfunction in other organs (affecting the tolerance
to e.g., fluid overload),
• the prevalent or expected solute burden (e.g.,in tumor lysis
syndrome),
• the need for fluid input related to nutrition or drug therapy

Would you dialyze?
Case 1
• Male patient
• 50 years old
• Diagnosed as Hepato-Renal syndrome type 1
• No facility for liver transplantation
• K: 3.5
• Compensated metabolic acidosis
• Creatinine: 4 mg/dl
• BUN: 110 mg/dl
• UOP: 300 mg/d

Would you dialyze?
Case 2
• Male patient
• 55 years old
• Admitted to ICU
• Sever chest infection and sepsis
• Serum creatinine & UOP:
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6
1.1 mg/dl 1.5 mg/dl 1.8 mg/dl 2.2 mg/dl 2.3 mg/dl 2.5 mg/dl
1 L/d 0.9 L/d 0.8 L/d 0.7 L/d 0.7 L/d 0.6 L/d

Would you dialyze?
Case 3
• Male patient
• 60 years old
• CHF
• Overloaded (massive lower limb edema, chest
clear)
• UOP (on maximum IV dose of diuretics): 0.8 L/d
• Creatinine: stable at 1.8 mg/dl

Marlies Ostermann et al. Nephrol Dial Transplant (2012) 0: 1–7
A proposed algorithm
for initiation RRT in
adult critically ill
patients

Sean M Bagshaw et al. Critical Care 2009, 13:317
A proposed algorithm
for initiation RRT in
adult critically ill
patients

Role of new biomarkers
Prediction of the need for RRT
American Journal of Kidney Diseases, Vol 54, No 6 (December), 2009: pp 1012-1024
A meta-analysis
including 1948
patients from
nine studies
confirmed that
urinary or plasma
NGAL indeed
predicted need
for RRT

When to Stop?

When to Stop?
Assessment of kidney function during RRT
• In IHD, the fluctuations of solute levels prevent achieving
a steady state.
• Changes in BUN and creatinine levels can also be
modified by nonrenal factors, such as volume status and
catabolic rate.
• In CRRT, continuous solute clearance of 25–35 ml/min
will stabilize serum markers after 48 hours. This allows
more reliable measurements of CrCl by the native
kidneys during CRRT.

When to Stop?
Shealy CB, Campbell RC, Hey JC, et al. 24-hr creatinine clearance as a guide for
CRRT withdrawal: a retrospective study (abstr). Blood Purif 2003;21: 192.

When to Stop?
Uchino S, Bellomo R, Morimatsu H, et al. Crit Care Med 2009; 37: 2576–2582.

How to Stop?
The process of stopping RRT may consist of:
• Simple discontinuation of RRT,
• or may include a change in the modality,
frequency, or duration of RRT.
No specific guidance can be provided for how to
manage the transition of RRT from continuous to
intermittent.

When to Stop?
It is also important to acknowledge that there may
be patients with a futile prognosis in whom RRT
would not be appropriate and where withholding
RRT constitutes good end-of-life care
Lassnigg A, Schmidlin D, Mouhieddine M et al. J Am Soc Nephrol 2004; 15:1597–1605

RRT Modalities
Marshall MR, Golper TA. Semin Dial. 2011;24:142-148.

RRT Modalities

Analyzing 15 RCTs in 1550 AKI patients
Cochrane Database Syst Rev 2007: CD003773.

Cochrane Database Syst Rev 2007: CD003773.

Hemodynamicaly stable patients

CRRT – Filtration Fraction
• UFR should not exceed 30% of the plasma water flow
rate (i.e., filtration fraction should be below 0.30).
• The problem can be resolved by:
– increasing Qb to at least 200 to 250 ml/ min
– or by diluting the blood and clotting factors with
replacement fluid before it reaches the hemofilter
(predilution)

Strategies to Reduce Intradialytic
Hemodynamic Instability During IRRT
• Increasing the frequency and treatment time of IRRT
minimizes ultrafiltration goals
• Bicarbonate-buffered dialysate
• Sodium profiling

Hemodynamicaly unstable patients / ↑ ICP

• Controversy exists as to which is the optimal RRT modality for patients
with AKI.
• In current clinical practice, the choice of the initial modality for RRT is
primarily based on:
– the availability
– experience
– patient’s hemodynamic status.
• In the presence of hemodynamic instability in patients with AKI, CRRT is
preferable to standard IHD.
• SLED may also be tolerated in hemodynamically unstable patients with AKI
in settings where other forms of CRRT are not available, (but data on
comparative efficacy and harm are limited).
• Once hemodynamic stability is achieved, treatment may be switched to
standard IHD.

VA/NIH Acute Renal Failure Trial Network, Palevsky PM et al. N Engl J Med. 2008;359:7-20

Kt/V urea has important limitations as a tool for
RRT dosing in AKI. AKI patients are metabolically
unstable, with variations in urea generation.
Ikizler TA, Sezer MT, Flakoll PJ, et al. Kidney Int 2004; 65: 725–732.

RENAL, Bellomo R, Cass A, Cole L, et al. N Engl J Med 2009; 361: 1627–1638.

Gawad
drgawad@gmail.com
Thank You

Dialytic Management of AKI - Dr. Gawad

Recommended

Recommended

More Related Content

Viewers also liked

Viewers also liked (10)

More from NephroTube - Dr.Gawad

More from NephroTube - Dr.Gawad (20)

Dialytic Management of AKI - Dr. Gawad