good ppt for undergraduate medical students

1. Renal Replacement Therapy (RRT) in children
Dr. Sabona Lemessa (Assistant professor in pediatrics and child health, JUMC)
8/12/2022 1

2. Outline
Case
Introduction
Indication for each RRT
Modalities of RRT
Advantage and disadvantage
Complication
Prescribtion
Reference
8/12/2022 2

3. Case 1
A 10-month-old infant with severe failure to thrive weighing 6 kg presents with diarrhoea and
septic shock not responsive to fluid resuscitation and requires inotropic support.
After 2 days the patient remains anuric and not responsive to fluid boluses and diuretics.
Examination shows that the infant is fluid overloaded with crackles in the lung bases and has an
enlarged palpable liver.
Blood results show a Na 130 mmol/l, K 8 mmol/l, Cl 110 mmol/l, urea 25 mmol/l, creatinine
200 umol/l and ABG pH 7.0, Bic 12.
depending on above information
1. How do you proceed the management?
2. Which modality of RRT preferable?
3. what complication should be anticipated?
8/12/2022 3

4. Introduction
RRT is a procedure which help to clear accumulated solutes, water or toxins from the blood by
diffusion or convection or both across a semipermeable membrane.
It replaces normal blood-filtering functions of the kidneys.
It replaces non-endocrine kidney function in patients with renal failure and
occasionally used for some forms of poisoning.
It could be intermittent or continuous.
8/12/2022 4

5. cont...
Between 7 & 66% of children with AKI will require RRT without which most will die.
acute RRT for AKI may be provided safely to children of all ages.
It is possible that variations in the timing of initiation, modalities, and/or dosing may affect clinical
outcomes,
 particularly survival, although few studies have directly examined these issues.
8/12/2022 5

6. Indication for RRT
Accepted urgent indications for RRT in patients with AKI generally include:
Refractory fluid overload
Severe hyperkalemia (plasma potassium concentration >6.5 mEq/L) or
rapidly rising potassium levels
Signs of uremia, such as pericarditis, encephalopathy, or an otherwise unexplained decline
in mental status
Severe metabolic acidosis (pH <7.1)
Certain alcohol and drug intoxications
Treatment-recalcitrant acidosis
Intoxication (salicylates, ethylene glycol, methanol, isopropanol, metformin, valproic
acid, lithium)
8/12/2022 6

7. cont...
 Severe hyperammonemia >400 µmol/l – infants with inborn errors of metabolism should be
rapidly hemodialyzed, once NH4 + exceeds 170 µmol/l,
seen with urea cycle disorders, maple syrup urine disease and
organic acidemias (these infants usually do not have AKI)
Urea and creatinine– no absolute threshold level for dialysis initiation;
decision to dialyze depends on overall clinical picture
Early dialysis may improve the outcome in some disease conditions
Hypercatabolic states (sepsis, burns, crush injuries) may require aggressive dialysis
Dialysis may be considered even if renal failure is not severe,
when there is a need to remove fluid or give blood products or nutritional support
8/12/2022 7

8. cont...
Fluid overload (exceeding 10–15%) is an independent predictor for-
mortality and prolonged hospital stay, and
one of the chief indications for dialysis.
Fluid overload is calculated as follows:
Fluid over load= (Fluid In － Out) × 100
Admission body weight
8/12/2022 8

9. cont...
Indications for Maintenance Dialysis in children with end-stage renal disease (ESRD)-
depends on a combination of biochemical, clinical, and psychosocial factors.
should be initiated early enough to prevent malnutrition and/or clinical symptoms of uremia.
it should be considered when the residual glomerular filtration rate (GFR) has declined to 9–15-
ml/min/1.73-m2 BSA and
Chronic dialysis should also be initiated despite a greater GFR when clinical and biochemical
complications as-
malnutrition, fluid overload, hypertension, hyperkalemia, acidosis,
decreasing growth velocity, or
neurological sequelae of uremia cannot be managed with medication and/or dietary
interventions only
Decreased school performance and restricted daily activities are also important factors in
children
8/12/2022 9

10. modalities of RRT
Factors influencing the Choice of RRT Modality include:-
 Goal of dialysis: ultrafiltration versus solute clearance versus toxin removal
 Clinical status of the child and hemodynamic stability
 Feasibility of peritoneal or large vascular access
 Training of medical personnel, institutional preference
 Need for anticoagulation
 Cost of treatment and supplies (important consideration not only in resource poor settings)
Choice of Various Modalities of RRT:- It could be intermittent or continuous.
Peritoneal dialysis (PD)
Intermittent hemodialysis (HD)
Continuous renal replacement therapy (CRRT)
8/12/2022 10

11. comparision of different modalities of RRT
8/12/2022 11

12. Acute Peritoneal dialysis (PD)
 the exchange of solutes and water between the blood (peritoneal capillaries) and the surrounding
tissue, and the dialysis solution across the peritoneal membrane.
Peritoneum acts as a filter & removes waste from blood.
 PD has been successfully used to treat AKI across all age groups, including
neonates following open heart surgery for CHD, in critically ill children with multiorgan
failure and
shock, infection and sepsis and following natural disasters.
It remains one of the most common RRT modalities in AKI in developing countries.
More than 68% of infants in LMICs were dialysed with PD.
8/12/2022 12

13. cont...
can be performed continuously or intermittently
two types of machine- Automated and Manual PD
requires much less technical expertise, expense, and equipment compared to IHD and CRRT.
It is also the most inexpensive of all acute dialysis therapies in children
 Technical requirements range from simple, improvised set ups to programmable devices (cycler) and
industry-manufactured sets of dialysate bags and tubing
 Duration of treatment, dialysate composition (specifically dextrose concentrations), exchange
frequency and fill volume are adjusted to the patient’s needs, anatomical limitations and hemodynamic
tolerability
8/12/2022 13

14. Principles of peritoneal dialysis
The peritoneal exchange process is the sum of two simultaneous and interrelated transport
mechanisms:
Diffusion refers to the movement of solute down a concentration gradient, whereas
Convection refers to movement of solutes that are ‘transported’ in a fluid flux,
 the magnitude of which is determined by the ultrafiltration rate
three types of pores:
Ultra-small transcellular water pores or channels, which comprise perhaps 1–2% of the
total pore area, yet account for 40% of water flow, and are driven by osmotic forces.
Small pores, which are 4–6 nm in diameter and comprise 90% of total pore area.
Large pores, which are greater than 40 nm in diameter and comprise the remaining 5–7%
of total pore area.
Although water moves through all three types of pores, only the small and large pores
allow convective solute transfer.
8/12/2022 14

15. Ultrafiltration and convection
The UF driving force in PD is determined by the osmotic pressure exerted by the dialysate glucose
concentration.
When designing the dialysis prescription in terms of ultrafiltration, children receiving CAPD with
1.5% or 4.25% dextrose as the osmotic agent should expect the drain volume to exceed the infused
volume of dialysate by 15–25% and 30–40%, respectively
Convective mass transfer, which is dependent upon fluid removal, contributes little to the
movement of small solutes, yet is responsible for most large solute removal.
During PD, fluid is lost continuously from the peritoneal cavity, both directly into the tissues
surrounding the peritoneal cavity as a result of the intraperitoneal hydraulic pressure and via
lymphatic vessels.
Whereas lymphatic absorption is thought to account for only 20% of fluid reabsorption by some
8/12/2022 15

16. Continuous flow PD with 2 PD catheters (Courtesy Peter Nourse)
Manual PD Automated PD
8/12/2022 16

17. 8/12/2022 17

18. Indications for Acute Peritoneal Dialysis
Renal Indications (AKI with or without Oligoanuria)
Oliguria in hemodynamically unstable patients
 Substantial bleeding risk: Presence of bleeding diathesis or hemorrhagic conditions
 Difficulty in obtaining large-bore blood access
Non-Renal Indications (with or without AKI)
 Refractory congestive heart failure
Severe acidosis
Severe hyperkalemia not controlled otherwise
Poisoning
Acute pancreatitis, Hepatic failure
8/12/2022 18

19. cont...
Simple to set up & perform
Easy to use in infants
Hemodynamic stability
No anti-coagulation
Bedside peritoneal access
Treat severe hypothermia or
hyperthermia
Unreliable ultrafiltration
Slow fluid & solute removal
Drainage failure & leakage
Catheter obstruction
Respiratory compromise
Hyperglycemia
Peritonitis
Not good for hyperammonemia or intoxication
with dialyzable poisons
Advantages Disadvantages
8/12/2022 19

20. cont...
Materials Required-
Rigid PD catheter
A 10 F neonatal chest drain tube may be used instead of a PD catheter in newborns
PD fluid: Lactate buffered electrolyte balanced dextrose solution is most often used.
Others Sterile dressing tray with suture materials, sterile surgical blade no. 11,
hypodermic sterile needle 18 G, urobag, IV sets, 2- and
3-way connectors, a Y connector set, 2 % lidocaine injection, and dressing
adhesive.
8/12/2022 20

21. Procedure
Catheterize the bladder.
 Ensure that the dialysis fluid is warmed to the body temperature.
 Prepare and drape abdomen with the patient in supine position.
 Identify the midpoint of the line joining the umbilicus to the pubic symphysis or in a neonate on a
paramedian line a little lateral to rectus sheath.
Give local anesthesia down to the peritoneum.
Insert an 18-gauge needle at the planned site and infuse 20–30 ml/kg of dialysate fluid to create a fluid
cushion.
Make a stab skin incision and insert the catheter with stylet perpendicular to the abdominal wall with a
twisting motion.
 Dialysis can be initiated in the immediate post-insertion period if there is urgent need for dialysis.
8/12/2022 21

22. Break-in protocol: immediate post-insertion period
8/12/2022 22

23. cont...
 The break-in period refers to the time immediately following catheter insertion
Routinely, dialysis is initiated 2–4 weeks post catheter insertion to allow adequate healing.
Penetration of peritoneum will be indicated by sudden feeling of “give way” and gush of dialysate fluid
out via the catheter.
Withdraw the stylet gradually, simultaneously advancing the catheter toward the opposite pelvic cavity.
Attach the connecting set to the catheter and run in dialysate
fluid to confirm free flow.
Allow about half of dialysate fluid to drain out by gravity.
Start the next in flow.
The initial 2–3 cycles can be rapid without a dwell time.
 Secure the catheter in place, if required with a purse string suture.
8/12/2022 23

24. Peritoneal Dialysis Prescription and Monitoring for Acute PD
 dwell volume is prescribed according to BSA, with target volumes adjusted to intraperitoneal pressure.
Dwell volumes =1,000–1,200 ml/m2 in patients older than 2 years and
600–800 ml/m2 for patients younger than 2 years are usually prescribed
Fill volume: 10–20 ml/kg, then increased to 30–40 ml/kg (800–1100 ml/m2) as long as
tolerated
The fill volume should not exceed a maximum of 2 lt.
run-in time 5–10 min, dwell time 20–30 min, and out flow time 10–20 min constitute the
usual dialysis prescription.
Each cycle usually lasts for 1 hr and avoid excessive abdominal distention and respiratory
compromise.
 UF can be increased by higher-strength glucose and shorter dwell times.
Fill volume exceeding a pressure of 18 cm H2O in supine position is associated with
abdominal pain and decreased respiratory vital capacity.
8/12/2022 24

25. cont...
The choice of dialysate fluid is tailored to the individual patient’s clinical needs considering fluid
balance, blood pressure, and peritoneal membrane characteristics
Glucose concentration: 2.5% if fluid overloaded, 1.5% if euvolaemic
Heparin 500 IU/l; KCl 4 mmol/l (once serum K below 4 mmol/l)
Addition of potassium to the dialysis fluid may be withheld for initial 8–10 cycles.
Dialysis can be continued for 48–72 h (total treatment time).
It is preferable to remove the acute PD catheter after 72 hr
risk of infection if the catheter is left in place for a longer period) and reinsert later if required.
Before removing the catheter, drain out dialysate fluid completely.
8/12/2022 25

26. Maintenance phase for patients in need of immediate dialysis
8/12/2022 26

27. Commercial Fluids for PD
Commercially available fluids are available for acute PD in 1.5%, 2.5% and 4.25% in both lactate
and bicarbonate buffered solutions
In situations of worsening acidosis despite PD it may be beneficial to use a bicarbonate-based
fluid.
This may occur in children with liver dysfunction or in small infants with liver immaturity
In low resource settings, it is acceptable to use hospital mixed solutions which can be made from
physiological intravenous fluids.
Mixing calcium and bicarbonate should be avoided because of the risk of precipitation
The addition of glucose will increase the ultrafiltration capacity and osmolality of the solutions.
8/12/2022 27

28. Hospital Mixed/Custom Made Fluids
8/12/2022 28

29. cont...
Modifications: in patients with pulmonary edema, dwell time can be shortened to 15–20 min and 2.5 %
dextrose containing PD fluid can be used to remove fluid rapidly.
Monitoring:
Maintain pulse, blood pressure, and intake/output hourly charts;
serum electrolytes and blood sugar every 8 h and
blood urea and creatinine every 24 h.
Watch changes in appearance of returning peritoneal fluid
infection, blood, fibrin threads.
Send PD fl uid for analysis: cell count, gram stain, culture, and
antibiotic sensitivity if patient is febrile or drained PD fluid color transparency is
altered.
8/12/2022 29

30. Adequacy of peritonial Dialysis
 Adequate control of body fluid volume and management of hypertension
 Preservation of residual renal function (RRF) as renal clearance is as important as peritoneal
clearance.
Residual renal function should be measured every 3 months
 Creatinine clearance:-The target value is >60 l/week per 1.73 m 2
Acidosis is corrected,
Blood urea level is reduced,
Correction of fluid & electrolyte disturbances,
8/12/2022 30

31. Non-infectious Complications of PD
8/12/2022 31

32. cont...
8/12/2022 32

33. 8/12/2022 33

34. Terminology of peritonitis
8/12/2022 34

35. case 2
A 16-year-old female with end-stage renal disease due to diabetic nephropathy is scheduled to start
hemodialysis next week.
She has poorly controlled blood sugars, along with moderate obesity (weight of 42 kg, body mass index
of 34 kg/m2).
Her blood pressure and proteinuria have been reasonably well controlled with lisinopril and atenolol.
She is moderately hypoalbuminemic (serum albumin of 3.4 g/dL [34 g/L]) and anemic (hemoglobin of
9.6 g/dL [96 g/L]), while her serum potassium and bicarbonate levels have been normal on alkali
supplementation.
She had dialysis catheter insertion into her right internal jugular vein and a creation of arteriovenous
fistula simultaneously this past week, after her blood urea nitrogen level surpassed 94 mg/dL
(33.9 mmol/L) the week prior.
depending on above information-
which modality of RRT indicated?
how do you prescribe?
8/12/2022 35

36. Intermittent Hemodialysis (HD)
Hemodialysis (HD) is an extracorporeal, intermittent form of renal replacement therapy (RRT).
Highly effective method to remove fluid and solutes in patients with AKI.
Fluid removal is limited in hemodynamically unstable patient.
Requires specialized nursing care.
Acute IHD can be performed using similar machinery and dialysis solutions as in chronic HD
preferred in hemodynamically stable patients with
primary renal disease (e.g., acute glomerulonephritis, hemolytic-uremic syndrome, or
In patients with inborn errors of metabolism or intoxications,
because very efficient small solute clearance can be obtained within a short period and
these patients will generally tolerate the procedure well
8/12/2022 36

37. cont...
Concentration gradient-driven diffusion process is the main principle underlying blood purification in
hemodialysis (HD),
which effectively eliminates small molecules such as urea
The rate of blood flow correlates directly with HD clearance (KHD).
It is a passive transfer of solute across a semipermeable membrane.
property of the dialysis membrane is the limiting factor as clearance rates gradually reduce at higher blood
flow rates.
The dialyzer efficacy in urea elimination (KoA) is dependent on the surface area of dialyzer, pore size, and
membrane thickness.
By increasing the rate of blood flow, clearance rate of urea can be augmented further by using high-
efficiency membrane (KoA >600 mL/min).
8/12/2022 37

38. Principles of Hemodialysis
Haemodialysis (HD), small molecular-weight waste chemicals in the blood diffuse across the
semipermeable membrane down their concentration gradients into the dialysis fluid outside.
The purpose of hemodialysis are:-
to mimic the role of the kidney,
removing waste products and solutes and fluids that have accumulated between dialysis sessions
The semipermeable membrane in the dialyzer allows:-
the passage of water and small molecular weight molecules and
inhibits the movement of larger molecules.
Solute transfer (clearance) occurs by:-
diffusion and convection, and
water is removed by ultrafiltration.
8/12/2022 38

39. cont...
 The goal of HD is to remove accumulated solutes (clearance) and water (ultrafiltration).
This is accomplished using a dialysis filter with a semipermeable membrane.
Solute Clearance:- occurs by diffusion and convection
affected solute clearance are dialyzer size (surface area), blood flow rate,
dialysis flow rate (normally 500–800 ml/min; 200 ml/min in SLED – slow low efficiency dialysis,
and dialyzer membrane characteristics.
Most dialyzers clear solutes up to a molecular weight 5,000–10,000 KD.
Convection refers to the passive movement of solutes across the semipermeable membrane along
with solvent (solvent drag) in response to a transmembrane pressure.
Middle size and larger molecules do not diffuse to a great extent, but may pass through the
dialyzer membrane by convection.
8/12/2022 39

40. cont...
Diffusion refers to migration of solutes across the semipermeable membrane down a concentration
gradient.
Small solutes such as urea nitrogen and potassium diffuse rapidly.
 Disequilibrium syndrome” (DES):- too rapid removal of solutes during dialysis will result in a rapid
decrease in serum osmolality and
an imbalance between serum and brain cell osmolality
causing movement of water into (higher osmolar) brain tissue and cerebral edema
High predialysis blood urea concentration increases the disequilibrium risk
presents with headache, nausea, and vomiting in mild cases and altered sensorium and seizures
in severe cases.
prevented by urea clearance should be limited during the first few dialysis sessions, aiming at a
blood urea reduction of not more than 30%.
Mannitol may be used as a prophylaxis.
If the predialysis blood urea levels are high, HD session should not last more than 1–2 h
8/12/2022 40

41. cont...
Ultrafiltration (UF):-
 The goal is to finish the dialysis session with the patient at the target weight, often referred to as “dry
weight”.
It is defined as the weight beyond which no further fluid removal is tolerated.
Excess fluid removal will result in hypotension, cramps, abdominal pain, headache, nausea, and
vomiting
Insufficient fluid removal will result in persistent fluid overload, contributing to hypertension and
congestive cardiac failure
Since the fluid is removed from intravascular space and the redistribution of fluid from extravascular
to intravascular space is not immediate,
aggressive fluid removal rates can lead to hypovolemic symptoms even if correct dry weight
is targeted.
8/12/2022 41

42. cont...
 The child’s dry weight adjusted periodically, to balance true body mass increase (and growth) against
weight loss due to poor nutrition or chronic inflammation.
Measures to achieve fluid removal without causing symptomatic hypotension are:-
“sodium modeling”, where the sodium concentration of the dialysate is set higher during early
dialysis, and
gradually reduced during the course of the dialysis session, and
“noninvasive volume monitoring” (acute change in hematocrit depicts acute change in blood
volume).
 Fluid removal is adjusted to target body weight; it should be less than 5 % body weight or not
more than 0.2 ml/kg/min.
8/12/2022 42

43. cont...
Factors that affect mass transfer are:-
Concentration gradient (dC)
Dialyzer surface area (A)
Dialyzer diffusivity (KO) for particular solute
Sum of resistances (Rb + Rm + Rd) ~ (dx/KO) where
Rb is mass transfer resistance of blood, Rm is mass transfer resistance of membrane, and
Rd is mass transfer resistance of dialysate
Countercurrent flow
Time
Mass Transfer= Driving Force /Resistance (J=KOA X dC/dX)
where J is diffusive mass transfer rate (mg/s) and
dC/dx is the change in concentration of the solute in relation to distance.
8/12/2022 43

44. Hemodialysis prescription
8/12/2022 44

45. cont...
8/12/2022 45

46. cont...
Patient monitoring/management of hypotension:-
Vital signs must be recorded at least every 30 min (every 15 min in PICU or children <15 kg)
Intradialytic hypotension may be prevented by Crit-Line monitoring and/or sodium modeling
Before beginning dialysis, orders should be in place for treatment of hypotension unresponsive to
adjustment in UF goal per Crit-Line
Saline bolus, 5 mL/kg
25% albumin 0.25 g/kg, maximum 12.5 g
Mannitol 0.25 g/kg, maximum 12.5 g
In PICU, vasopressor support may be considered to correct dialysis associated hypotension.
8/12/2022 46

47. 47
8/12/2022

48. Dialysis Adequacy
Urea reduction rate (URR) = (1 − urea post HD/urea pre HD) × 100.
Adequate dialysis should yield a URR >65 %.
adequacy of ultrafiltration,
good control of blood pressure, anemia
good control of acidosis, bone disease, and patient well-being.
8/12/2022 48

49. Complications of HD
Intradialytic Hypotension
Disequilibrium syndrome
Air Embolism- give 100% 02, head down left lateral position, clumping
Anaphylaxis- can occur at any time, but is more common after first use (“first use syndrome”)
Dialysis-related amyloidosis
Hemolysis
Fistula Stenosis and Other Complications
Catheter-Related Infection
8/12/2022 49

50. case 3
A 30 kg child with leukemia develops septic shock with multi-organ system failure including the need
for intubation, vasopressor support for hemodynamic compromise, as well as progressive oliguria with
both solute and fluid retention.
Current ventilator settings include a FIO2 delivery of 70%, a PEEP of 10.
Blood pressure is currently 98/45 with 1 mic/kg/min of norepinephrine adjustment to keep at systolic
>110 mmHg.
The child is febrile with a temperature of 39 °C.
Fluid overload calculations reveal that the child is 15% above dry weight with insufficient urine output
to allow for adequate room for medications, nutrition, and overall medical care.
Labs reveal a BUN of 69 mg/dL, a Cr of 2.3 mg/dL, and a K of 5.9 meq/dL.
1. What is the optimal way to deliver renal support?
2. What is the impact of renal support on medical (and vasopressor) clearance?
3. What is the optimal location of vascular access?
4. What is the optimal prescription?
5. How much fluid can be removed safely?
8/12/2022 50

51. Continuous Renal Replacement Therapies (CRRT)
 CRRT is any form of RRT that is used 24 h a day
CRRT is a continuous from of dialysis for the management of critically ill patients with AKI.
It is generally performed in intensive (critical) care units
Although PD shares many CRRT attributes, the term is generally applied to extracorporeal forms of dialysis
can be delivered as filtration- (solute removal by convection) or dialysis based modality (solute removal by
diffusion), or as a combination of both
CRRT permits slower removal of solutes and fluid per unit time compared with conventional HD and
is often better tolerated by hemodynamically unstable patients
 convective solutions are considered a drug and can be placed in the vascular space but that diffusive
solutions are considered a device and should only be placed in the extravascular space.
8/12/2022 51

52. Nomenclature for CRRT
 SCUF (Slow Continuous Ultra Filtration): used for fluid removal in volume overloaded
patients.
The ultrafiltrate (UF) is not replaced.
Solute clearance is insignificant.
occasionally combined with ECMO (extracorporeal membrane oxygenation) using a
parallel (small-caliber) circuit
 CVVH (Continuous Veno-Venous Hemofi ltration):
filtration based continuous treatment (solute removal by convection).
A replacement fl uid is infused in the circuit just before or after the hemofilter (pre- or
post-dilution).
Clearance of solutes is convective (“solute drag”) and depends on UF rate generated by
the transmembrane pressure
8/12/2022 52

53. Slow continuous ultrafi ltration (SCUF)
8/12/2022 53

54. cont...
 CVVHD (continuous veno-venous hemodialysis):
dialysis-based treatment (solute removal by diffusion).
Blood flows through the capillaries of a dialyzer;
countercurrent flow dialysate is delivered through the dialysate compartment.
Replacement solution is not required.
Solute clearance is mainly diffusive and limited to small molecules
 CVVHDF (Continuous Veno-Venous Hemodiafiltration):
simultaneous removal of fluid (filtration) and solutes.
Replacement solution is needed to maintain fluid balance.
Solutes are cleared by convection and diffusion.
CVVHDF effectively removes small and large molecules
8/12/2022 54

55. Continuous veno-venous hemofiltration (CVVH)
8/12/2022 55

56. Cont…CRRT
Indications
Critically ill, hemodynamically unstable patients
diuretic resistant fluid overload
severe metabolic acidosis (pH <7.2)
 refractory hyperkalemia (K+ >6.5)
Neonates & infants with cardiovascular or abdominal surgery, trauma with shock and
multisystem failure.
Rapid generation of toxic metabolites
Tumor lysis syndrome.
8/12/2022 56

57. Advantages of CRRT
 Hemodynamically unstable patients may not tolerate rapid fluid removal with (conventional) intermittent
hemodialysis.
CRRT is hemodynamically well tolerated.
Their change in plasma osmolality is minimal.
can help to preserve metabolic stability in critically ill patients and
maintain fluid balance in oliguric patients who require IV medications, blood products or parenteral nutrition.
It is highly effective in removing excess fluid.
Episodes of hypertension are less likely to occur with CRRT than with HD,
decreasing the risk of further insults to the kidneys.
will often allow for extracorporeal cooling as well as for clearance of solute.
8/12/2022 57

58. Disadvantages of CRRT
 Prolonged anticoagulation
Hypothermia – use blood warmer, especially in infants.
Dyselectrolytemia – Potassium and phosphate losses can be excessive.
Solute clearance – CRRT is inferior to HD.
Depletion of trace elements, essential peptides and (benefi cial) cytokines.
Requires thorough training of nurses, technicians and physicians and is personnel intensive.
Expensive equipment and supplies burden health care system, especially where resources are
limited.
Requires a vascular access (in contrast to acute PD).
Drug elimination differs from conventional HD; pharmacokinetic data are scarce and vary between
CRRT modalities.
8/12/2022 58

59. 8/12/2022 59

60. CRRT prescription
8/12/2022 60

61. cont...
8/12/2022 61

62. Commercially available CRRT solutions
8/12/2022 62

63. Complications of CRRT
 Bleeding
Hypotension – excessive ultra fi ltration
Hypothermia – use blood warmer, especially in infants
Membrane reactions – Bradykinin Release Syndrome (BRS), which may be perpetuated by acidic blood
(PRBC).
Administration of NaHCO 3 prior to CRRT (e.g. if serum HCO3<26 mmol/l) may reduce risk of
bradykinin release
Metabolic alkalosis and “citrate lock” (patient’s total calcium level rises while ionized calcium level
remains normal)
suggests that citrate administration exceeds citrate clearance Clotting in the circuit
Infection
Electrolyte imbalance (hypokalemia, hypomagnesemia, hypophosphatemia)
Loss of nutrients
8/12/2022 63

64. Changes in Nutrition When on Renal Replacement Therapy
Renal replacement therapy (RRT) allows for “room” to give sufficient nutrition.
Modalities of RRT have unique impact upon losses of nutrition
Hemodialysis (high flux or standard) or sustained low efficiency dialysis (SLED)
will have impact upon trace mineral losses as well as
impact upon water-soluble vitamins but less impact upon other components of nutrition.
Peritoneal dialysis (PD) will effect losses of amino acids and proteins with larger protein losses including
albumin.
 In patients on PD, 10 % of total calorie intake can be absorbed via dextrose from the dialysate
One can assess this by looking at a nitrogen balance measuring protein losses in the PD effluent and
replacing it proportionally.
8/12/2022 64

65. cont...
Continuous renal replacement therapy (CRRT) delivered by CVVHD was found to remove 10–20% of
the amino acid daily intake.
Clearance of amino acids in children on CRRT was in the range of 20–40 ml/min/1.73 m2
glutamine losses during CRRT accounted for 25% of all amino acid losses.
 to account for losses in the ultrafiltrate/dialysate, additional 10–20% of amino acid intake should
be supplemented to the diet.
Vitamins and Trace Elements-
For children managed by CRRT, losses of water-soluble vitamins are likely over time.
Thus, when supported on CRRT over prolonged periods >10 days, serum levels should be
monitored, and additional supplementation may be required
Folate, being water soluble, was likewise found to be cleared readily on CRRT and
it is possible that additional folate supplementation is needed in children who are receiving CRRT
for prolonged periods
Patients, who do not achieve desired intake with enteral feeding, are considered for parenteral
alimentation
8/12/2022 65

66. Route and Timing of Nutritional Support
Current 2017 ASPEN recommendations include beginning within the first 24–48 h of PICU
admission.
enteral nutrition as the primary route unless clear contra-indications are present.
Feeding by an enteral route has been shown to reduce the risk of nosocomial infection and is cost-
effective.
 A goal of providing at least 2/3 of the daily energy expenditure by day 5–7 of the PICU stay
should be sought.
AKI, daily protein intake should be in the order of at least 2–3 g/kg/day in children with AKI.
During RRT, commensurate adjustment of protein intake must be made to account for losses (10–
20 % of amino acid intake).
8/12/2022 66

67. Nutrition prescription in AKI children
8/12/2022 67

68. Recommended Calorie, Protein, Calcium and Phosphorous Intake
8/12/2022 68

69. Reference
 Indra Gupta and Martin Bitzan, on renal replacement therapy Manual of Pediatric Nephrology,
Verlag Berlin Heidelberg 2014.
Mignon McCulloch, Sidharth Kumar Sethi, Ilana Webber, and Peter Nourse on renal replacement
therapy, Critical Care Pediatric Nephrology and Dialysis: A Practical Handbook, 2019.
Lesley Rees, Ellis D. Avner on renal dialysis Pediatric Nephrology Seventh Edition.
Jordan M Symons and Sandra L Watkins on hemodialysis Clinical Pediatric Nephrology 2nd
Edition.
Prasad Devarajan, on management of acute kidney injury, Nelson 21st edition.
8/12/2022 69

70. Thank you
8/12/2022 70