Transcript Methods of purifying water

Water Treatment Unit
For Hemodialysis machines
Hemodialysis Solution
Dialysis solution is prepared from
Purified water
+
Concentrate
Water – significance for the patient

Needed by a human being app. 500- 800 litres
per every treatment

Dialysis patients need app. 20 m3 /yr

Demands of water for dialysis is very high
Types of pollution

Organic pollutants
particles, colloids, bacteria, pyrogens,
chloramines, pesticides

Inorganic pollutants
monovalent/ polyvalent ions, especially
calcium, sodium, magnesium, nitrate, copper,
aluminium etc.
Colloids
+
+ - +
- +- -+
- + - +
+
+
+ - +
- +- -+
- + - +
+
Water contamination is harmful for dialysis patient:
is added for/by:
Complications:
Aluminum:
Flocculating
suspended
particles
Anemia,
dementia, bone
disease
Chloramine:
Preventing
bacterial
proliferation
Hemolytic
anemia
Reduce
tooth decay
Pruritis,
Nausea, Atrial
fibrillation
Copper, Zinc
Lead
Metal pipes
Hemolytic
anemia,
toxicity
Bacteria and
Endotoxins
Contaminated
water
Pyrogenic
reactions
Fluoride:
Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
Installation of water pre-treatment and
RO system

Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
pretreatment:
 Water softener
 Carbon adsorption
Softener:
SOFTENER
Carbon adsorption:
Adsorption by activated Carbone
Is utilized to remove
Chlorine and Chloramines
2-Activated carbon filter for adsorption
 principle:
*van der Waals forces
*high specific surface
(100g act. carbon – ca. 100.00 m2)
◊ remove chlorine from
drinking water
Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
Primary purification:
 Reverse osmosis
 Deionization
Reverse osmosis:
 It removes more than 95% of ionic
contamination and nonionic contaminations
Principle of Osmosis
Osmotic pressure
clear water
saline solution
semipermeable membrane
Principle of Reverse Osmosis
pressure
clear water
saline solution
semipermeable membrane
Reverse osmosis apparatus
Direct and indirect water feed distribution system
Deionization:
Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
Methods of purifying water:
 Pretreatment
 Primary purification
 Distribution
The main function of the
dialysate, is to remove waste
material from the blood and to
keep useful material from leaving
the blood. Electrolytes and water
are some materials included in the
dialysate so that their level in the
blood can be controlled
Dialysis solutions preparation:
 Fixed volumes of dialysate concentrate mixed with
fix volumes of heated purified water
 The final dialysate solution is checked by
conductivity
Biff F. Palmer
Bicarbonate powder obviates the
problem of bicarbonate growth in bicarbonate solutions
Hemodialysis solution

Concentrations
hemodialysis :

Sodium (meq/L) 135 to 155
Potassium (meq/L) 0 to 4
Calcium (mmol/L) 1.25 to 1.75 (2.5 to 3.5 meq/L)
Magnesium (mmol/L) 0 to 0.75 (0 to 1.5 meq/L)
Chloride (meq/L) 87 to 120
Bicarbonate (meq/L) 25 to 40
Glucose (g/dL) 0 to 0.20






of
dialysate
components
used
in
Acetate buffer
In early 1960s acetate was standard buffer 
Acetate lead to cardiovascular instability 
and hypotension during dialysis.
Acetate buffer
Hemodynamic instability
 Pts with reduced mass muscle more
intolerant to acetate buffer included
malnourished Pts,elderly Pts and women.

Bicarbonate (meq/L) 25 to 40
Standard solutions have 35 or 38 meq/L
 In alkalemic pts (metabolic or respiratory)
standard solutions must be changed to a
solution with 20-28 meq/L of bicarbonate
 Concentration of base adjusted to a
predialysis plasma con of 20-23 meq/L
 Con beyond 20-23 meq/L increased risk of
Ca-P precipatation and cardiac arrhythmia

Acid
Concentrate
Bicarbonate
Concentrate
(acetic acid, citric acid,
Na, K, Mg, Cl, dextrose
NaHCO3
HCO3
+ H+ = H2CO3
PH: 7-7.4
NaHco3 = 32mmol ± 8 mmol
Bicarbonate Concentration for
Acidotic Patient =35-38 mEq/L
Sodium level:135-145meq/L
Dialysate with low Na level predispose to
hypotension and cramps because of
hypoosmolality and more fluid shifting from
extracellular space to intracellular space.
 Dialysate with high Na level may cause
thirst and weight gain and prevent
hypotension during dialysis.

Standard Dilution
1 + 34
Variable
1 + 25
1 + 37
Acetate
135mmol
Base Na
Bicarbonate 138mmol
NaHco3 + Acid Solution
32mmol + 106 mmol
Potassium level :0-4meq/L
Usual dialysis K level is 2 meq/L unless
predialysis plasma K is less than 4.5 or
unless patient is receiving digitalis.
 In the two instances ,dialysis K level is 3
meq/L

Calcium level:2.5-3.5 meq/L
In pts taking calcium-containing
phosphorus Ca level is 2.5 meq/L
 In pts taking newer phosphate binder
which don’t contain Ca , Ca level may
increased towards 3.5meq/L

A “Standard” HD Delivery System
Informational Display
PT = Pressure
Transducer
Saline
Anticoagulant
PT
Blood from Patient
Blood Leak
Detector
Dialysate / UF Out
(green / yellow)
PT
Conductivity
Meter
Dialysate In
Mixing
System
PT
Drip Chamber
Air
Detector
Pre-mixed or
sorbent
Water,
Acid
regenerated
Concentrate,
dialysate
Bicarbonate
Concentrate In
Venous
clamp
Blood return to
Patient
‫غلظت نهایی مایع دیالیز استات‬
‫غلظت نهایی مایع دیالیز‬
‫بیکربنات‬
Na :135meq/l

Na :106 + 32 meq/l

K:1 & 2 meq/l

K:1 & 2 meq/l

Mg:1 meq/l

Mg:1 meq/l

Ca:2.5 meq/l

Ca:2.5 meq/l

Cl:104 meq/l

Cl:111.5 meq/l

Acetate :35 meq/l

Acetate :3.5 meq/l

Glucose : 200mg/dl

Glucose : 200mg/dl

Bicarbonate :32 meq

What is sodium modeling in
hemodialysis patients?
Fluid removal
Plasma refilling
Fluid removal
Fluid removal
Na
Low Na
130-135 meq/l
Na
Increased risk of
hypotension
Historically the dialysate Na was
maintained at hyponatremic level, 130-135:
To prevent:
 Intradialytic hypertension
 Thirsty
 Interdialytic weight gain
Disadvantages of dialysates with low
sodium concentration:
 Increased risk of hypotension
 Increased risk of intradialytic cramps
 Increased risk of dialysis disequilibrium
syndrome
Water movement during standard hemodialysis
Intracellular fluid
Extracellular fluid
Dialyzer
step3
Water movement
step1
280
Osmolality
320 mosm/kg
Osmolality
320 mosm/kg
Falling to
290mosm/kg
as diffusion occurs
Compensatory refilling
step2
Loss of urea
and water
urea removed
by dialyzer
urea sequestration
in tissue
fluid
Effluent
Dialysate
Increased intracellular
osmolarity
Inffluent
Dialysate
fluid
Na
Causes of Intradialytic hypotension(IDH)
Excessive fluid removal
Ultrafiltration rate > 0.35 ml/min/kg
Decrease in plasma vol. > 20%
Reduced
plasma
refilling rate
Reduced ECV
Hemorrhage
Impaired
Vasoconstriction
Intradialytic
Hypotension
Myocardial Infarction
Structural heart dis.
Pericardial tamponade
Autonomic neuropathy (e.g. DM, Uremia)
Antihypertensive medications
Sympathetic failure (적절한 plasma NE↑가 無)
RAS and arginine-vasopressin syst. sensitivity↓
Food ingestion(splanchnic vasodilation)
Tissue ischemia(adenosine mediated)
Bacterial sepsis
Intradialytic venous pooling
Core body temp.↑
Anemia.
Dialysis-related factors
Heart problems
Arrythmias
Patient-related factors
Hemolysis
Dialyzer Rxn
Air embolism
Acetate dalysate (adenosine-mediated)
Low dialysate Na &/or ionized Ca conc.
Complemant activation (C3a and C5a-mediated)
Cytokine generation(IL-1 and NO-mediated)
High dialysate sodium:
Advantages:
Disadvantages:
 Decreased risk of
hypotension
 Increased rate of
hypertension
 Decreased risk of
intradialytic cramps
 Interdialytic weight gain
 Decreased risk of dialysis
disequilibrium syndrome
 Polydipsia
Fluid removal
Plasma refilling
Na
Low Na >145 meq/l
Na
Different patterns of sodium modeling
145-155 meq/lit
Na concentration
135-140 meq/lit
Hours after dialysis initiation
Dialysate Na should be regulated based on
serum Na:
hyponatremia:
 If Na > 130: Dialysate Na: 140-(140-predialysis Na)
 If Na<130: Dialysate Na: Predialysis Na + 15-20
Hypernatremia:
 Dialysate Na: Predialysis Na-2 mmol