404fm.2 continuous renal replacement therapy (crrt… · 404fm.2 continuous renal replacement...
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Guideline 404FM.2 1 of 15 Uncontrolled if printed
404FM.2 CONTINUOUS RENAL REPLACEMENT THERAPY (CRRT) USING CITRATE
Target Audience: Hospital only ICU
(Based on Gambro and Kalmar Hospital protocols)
CRRT using regional citrate anticoagulation
This is a therapy which is used in Critical Care as a supportive mechanism for those patients who have developed an acute kidney injury (AKI). AKI is characterised by a rapid reduction in kidney function resulting in a failure to maintain fluid, electrolyte and acid-base homoeostasis (Lewington and Kanagasundaram, 2011).
The aim of therapy is to replace normal glomerular filtration by:
Relieving hypervolaemia and maintaining fluid balance.
Removing excess urea and creatinine.
Correcting and maintaining metabolic and electrolyte balance.
Continuous renal replacement therapy (CRRT) allows fluid and waste products to be removed while maintaining cardiovascular stability in critically ill patients who respond poorly to intense dialysis therapy, delivered over a three to four hour period.
Citrate chelates calcium in the blood flowing through the filter, temporarily removing it from the clotting pathway, thereby preventing intra-filter clot formation. The citrate infused blood passes through the filter, and calcium is replaced via an infusion to the patient, thereby enabling regional anticoagulation of the filter, without systemically anticoagulating the patient. On metabolism by the liver, skeletal muscle and kidneys, each citrate molecule breaks down to release three bicarbonate ions and the remaining chelated calcium which has not passed into the effluent fluid. SET UP AND STARTING TREATMENT
Before starting treatment Check the daily blood results before the start of treatment, including:
Total calcium (not the corrected value)
Magnesium, phosphate, potassium and bicarbonate levels
Ionised calcium (arterial blood gas)
Calcium levels should be corrected prior to treatment starting, as this will ensure the patient has sufficient calcium reserves for clotting, and will prevent masking of citrate accumulation signs. Potassium and magnesium correction should not delay starting the filter. APTT levels will NOT be required for citrate anticoagulation.
Equipment needed
1 ST150 Prismaflex® kit
1 CA250 calcium line
1 x 50 ml Luer lock syringe
1 x 5 litre bag of Prismocitrate® 18/0 (citrate used as pre-dilution)
1 x 5 litre bag of Prism0cal® B22 (calcium-free dialysate solution)
1 x 5 litre bag of Phoxilium® (post-dilution replacement solution)
2 x 1 litre bags of 0.9% sodium chloride (priming solution)
11.3 mmol calcium gluconate in 50 ml (neat) as calcium replacement
Sterile dressing pack and trolley
2 x 5 ml syringes to withdraw hep-lock, 2 x 20 ml syringes to check flow (20 ml in 6 seconds), 2 x 10 ml syringes for sodium chloride flush.
Guideline 404FM.2 2 of 15 Uncontrolled if printed
Setting up and priming
Switch the machine on, input the patient details, ensure accurate patient weight and haematocrit is entered. This will impact on the therapy delivery.
Choose the CVVHDF option.
Choose citrate-calcium via the Prismaflex® syringe pump.
Follow the on-screen step-by-step installation instructions.
Install Prismocitrate® 18/0 on the white scale (PBP = pre-blood pump).
Install Prism0cal® B22 on the green scale (dialysate).
Install Phoxilium® on the purple scale (replacement). Ensure the replacement solution indicates calcium concentration of 1.25 mmol/L. If not, call the shift leader.
Prime the ST150 with 2 litres of 0.9% sodium chloride (no heparin required).
Install the calcium gluconate syringe into the Prismaflex® syringe pump. This should be a Terumo Luer Lock syringe. Leave the calcium line unclamped for priming by the Prismaflex® machine, do not connect to the patient at this stage (risk of air embolism).
Ensure fluid loss/gain limit is set to 400 ml/3 hours, this is a default setting do not change.
Starting parameters
Mode: CVVHDF
Starting citrate dose: 3.0 mmol/L blood
Starting calcium compensation: 100%
Flow settings: Based on actual body weight
Weight (kg) Blood flow
(ml/min)
Dialysate
(ml/hr)
Replacement
post-filter
(ml/hr)
Actual treatment
dose obtained
(ml/kg/hr)
50 100 1000 400 41
60 110 1100 500 39
70 120 1200 500 35
80 130 1300 500 33
90 140 1400 500 31
100 150 1500 600 31
110 160 1600 700 30
120 170 1700 800 30
130+ 180 1800 1000 30
If the patient is severely metabolically acidotic, please see trouble shooting flow
sheets for alternate action. In severely acidotic septic patients move up 2 weight
brackets, more than this risks electrolytes correcting too quickly. If acidosis is not
correcting fast enough, increase blood pump speed; this delivers more citrate and
through metabolism releases 3 bicarbonate ions to the patient.
For higher blood flow speeds, consider starting at a lower rate, then building to the
required rate when the patient is haemodynamically stable.
If starting at a lower blood flow speed than suggested above, the replacement and
dialysate rates should still be according to the table values for the patient’s weight.
If starting at a lower blood flow rate, wait 1 hour after achieving the desired blood flow
before measuring the calcium levels.
Actual treatment dose is effluent minus 15% downtime.
Guideline 404FM.2 3 of 15 Uncontrolled if printed
Connection
Using a sterile pack and sterile gloves to access the vascath, ensure flow test is performed.
1. Withdraw 5 ml blood from the red vascath port to remove hep-lock and discard onto
gauze (observe for clots).
2. Withdraw and replace 20 ml blood. Flow should be sufficient to withdraw 20 ml blood
from the vascath in 6 seconds or less.
3. Flush with 10 ml 0.9% sodium chloride.
4. Repeat on the blue vascath port.
Do not start treatment if there is a flow problem. Alert the consultant and the nurse in
charge if this is the case. Vascath should be reviewed.
1. Ensure that the primed filter waits no longer than 30 minutes before connection.
2. Let the shift leader and unit doctor know the filter will be starting imminently, have fluid for
a fluid challenge available in the bed space, in case of haemodynamic instability.
3. Connect red access line to the red vascath port.
4. Connect blue return line to the blue vascath port.
5. Connect yellow line to effluent bag.
6. (A) Connect calcium line to central line.
(B) Alternatively if a 3 lumen vascath has been inserted the third lumen can be used for
calcium only.
(C) If these options aren’t available a Y connector secured to the RETURN line only (as
seen in the picture below) can be used.
7. Unclamp all lines.
8. START treatment.
9. Once patient is stable, increase blood pump speed to required level as above.
10. Set patient fluid removal as required.
Calcium infusion only Access line
Tri Lumen Gam Cath from Gambro Y connector set up
(Option B) (Option C) Calcium line Return line
Y connector Tape these 2 points
Guideline 404FM.2 4 of 15 Uncontrolled if printed
TREATMENT MONITORING
Calcium monitoring Initially And then:
Post-filter ionised calcium
(blood gas from haemofilter circuit)
Target 0.25 to 0.50 mmol/l
Hourly until within normal values
6 hourly
Patient systemic ionised blood calcium
(blood gas from patient)
Target 1.0 to 1.3 mmol/l
Hourly until within normal values
6 hourly
Patient total calcium
(not corrected calcium)
Target 2.20 to 2.50 mmol/l
After 6 hours 12 hourly with
U&E
Calcium ratio
(Total Ca ÷ patient's systemic ionised Ca)
Target ratio <2.5
After 6 hours 12 hourly with
U&E
1. Ionised calcium – post-filter and patient
One hour after treatment is initiated and blood flow established, make two ionised calcium checks (one from the blue port on the set and another from the patient’s arterial line) and alter according to the following table:
Filter Ca2+ >0.5 Filter Ca2+ 0.25 - 0.5 Filter Ca2+ <0.25
Patient Ca2+ <1.0
Increase citrate dose by 0.5 mmol/l blood
Increase calcium compensation by 10%
Increase calcium compensation by
10%
Decrease citrate dose
by 0.5 mmol/l blood.
Patient Ca2+
1.0 - 1.3
Increase citrate dose by 0.5 mmol/l blood
NORMAL IDEAL VALUES
Decrease citrate dose by 0.5 mmol/l blood.
Patient Ca2+ >1.3
Decrease calcium compensation by
10%
Decrease calcium compensation by
10%
Decrease calcium compensation by 10%
Decrease citrate dose by 0.5 mmol/l blood
Check post-filter ionised calcium and patient calcium levels hourly until ideal values have
been established.
Once two consecutive measurements are within the normal range, check the post-filter
ionised calcium four times a day (every 6 hours).
Increase back to hourly should values alter to outside the normal ideal values.
Do not take any blood for analysis from the filter set, other than for calcium.
Do not make any adjustments to therapy unless confirmed by the shift co-ordinator or ICU consultant.
Check the effect of the changes to the patient by pressing the view changes button on the filter.
Guideline 404FM.2 5 of 15 Uncontrolled if printed
If the citrate dose is reduced, the pre-blood pump flow and hence total effluent dose will also fall. If the total effluent dose falls below 30 ml/kg/h, increase the replacement flow until a dose of 30 ml/kg/h is achieved.
If there are any changes in citrate dose or blood flow rate, hourly checks need to be carried out until 2 consecutive stable results are achieved again.
2. Calcium ratio monitoring
Measure the patient’s total calcium level at 6 hours by sending a U&E sample to Biochemistry.
Calculate the calcium ratio by dividing the patient’s total uncorrected calcium, by the patient’s ionised calcium (total Ca ÷ ionised Ca).
The ratio is to be calculated every 12 hours and documented on the blood results flow chart.
Increasing requirements for calcium compensation could indicate citrate accumulation. Please see trouble shooting flow sheets for actions to be considered.
3. Frequency of blood tests
Test Frequency
U&E 6 hourly initially. 12 hourly when stable.
Potassium At least 6 hourly. More frequent if unstable.
Glucose At least 6 hourly. More frequent if unstable.
FBC 12 hourly with U&E.
Magnesium and phosphate 12 hourly with U&E.
Post-filter ionised calcium Hourly until normal values achieved. 6 hourly when stable.
Patient systemic ionised calcium Hourly until normal values achieved. 6 hourly when stable.
Patient total calcium 6 hours after filtration commenced. 12 hourly when stable.
Calcium ratio 6 hours after filtration commenced. 12 hourly when stable.
Guideline 404FM.2 6 of 15 Uncontrolled if printed
PAUSING TREATMENT AND RECIRCULATION (no clotting noted in the set or lines)
If the patient needs to be temporarily disconnected, it is possible to recirculate the blood through the filter to prevent clot formation. There are 2 recirculation options available:
Sodium chloride recirculation – after returning the blood, sodium chloride is circulated through the blood lines of the filter. The filter set will need to be re-primed before the patient is reconnected. Max 120 minutes.
Blood recirculation – after the patient has been disconnected (without returning the blood) the filter re-circulates blood in the filter blood lines after to reduce the chance of clotting. Max 60 minutes.
N.B. If any clotting is noticed in the set or lines return of blood and recirculation must NOT be performed. In this instance STOP the treatment and prime a new set when the patient is ready to be reconnected.
Sodium chloride Recirculation Procedure
Gather equipment needed: o 250 ml 0.9% sodium chloride. o 1 x Y connector and 2 spikes. o Dressing pack and trolley. o 4 x 10 ml syringes (2 to withdraw blood and 2 to flush vascath). o 2 x 10 ml 0.9% sodium chloride ampoules. o 2 x 2.5 ml syringes and heparin for hep-lock procedure, and 2 bungs. o Equipment as indicated for priming and connection.
Press stop.
Stop the calcium infusion and disconnect.
Select “ Recirc” option on the stop screen.
Select “Sodium chloride Recirc” option on the recirculation options screen.
Follow the on screen instructions exactly: o Hang the 250 ml bag of sodium chloride on the priming hook, connect the Y
connector to the sodium chloride with the spike and prime the Y connector with sodium chloride.
o Using the dressing pack and ANTT, disconnect the access line from the patient and connect the access line to the 250 ml sodium chloride bag via the Y connector. Enter the desired blood return settings.
o Return the blood to the patient. o Flush the disconnected vascath port, hep-lock (except in heparin-induced
thrombocytopenia (HIT) patients) and cap. o Enter the desired recirculation rate (can be changed during recirculation). o Disconnect the return line from the patient and connect the return line to the
sodium chloride bag and begin recirculation. o Flush the newly disconnected vascath port, hep-lock (except in HIT patients) and
cap and label the vascath, document the time and details on the haemofilter observations chart.
When you are ready for reconnection: o Prepare a new calcium syringe and calcium line. o Stop recirculation. o Clamp the Y line. Using ANTT, disconnect the access line and reconnect it to a
new spike, spike a 1 litre bag of sodium chloride and hang this on the priming hook.
o Connect the return line to a new empty prime collection (effluent) bag. o Change the calcium syringe and line, prime the calcium line. o Prime the filter set. o When the machine has passed the Prime Test, reconnect the patient as per
“Connection” on page 3. o Document the time and details on the haemofilter observations chart.
Guideline 404FM.2 7 of 15 Uncontrolled if printed
Blood Recirculation Procedure
Gather equipment needed: o Y connector o Spike o 100 ml 0.9% sodium chloride bag o Dressing pack and trolley o 4 x 10 ml syringes (2 to withdraw blood and 2 to flush vascath) o 2 x 10 ml 0.9% sodium chloride ampoules o 2 x 2.5 ml syringes and heparin for hep-lock procedure, and 2 bungs o Equipment as indicated for connection
Press stop.
Stop the calcium infusion and disconnect.
Select “ Recirc” option on the stop screen.
Select “Blood Recirc” option
Follow the on screen instructions exactly: o Hang the 100 ml bag of sodium chloride on the priming hook, connect the Y
connector to the sodium chloride with the spike and prime the Y connector with sodium chloride.
o Using the dressing pack and ANTT, disconnect the access line from the patient and connect the access and return lines to the 100 ml sodium chloride bag via the Y connector. Repeat with the return line.
o Flush, hep-lock (except in HIT patients), cap and label the vascath. o Select “Start Recirc” o Document the time and details on the haemofilter observations chart.
When you are ready for reconnection: o Prepare a new calcium syringe and calcium line. o Stop recirculation. o Select “Change Syr + Line” install a new calcium syringe and line. o Reconnect the patient as per “Connection” on page 3. o Document the time and details on the haemofilter observations chart.
STOPPING TREATMENT & DISCONNECTION
There are 2 options:
End Treatment – to terminate the current treatment; or
Change Set – if the circuit has expired or clotted.
End Treatment
Gather equipment needed: o Dressing pack and trolley. o 4 x 10 ml syringes (2 to withdraw blood and 2 to flush vascath). o 2 x 10 ml 0.9% sodium chloride ampoules. o 2 x 2.5 ml syringes and heparin for hep-lock procedure, and 2 bungs. o 2 appropriate bin liners and closure.
Press stop and select “End Treatment”
If there is no clotting evident in the set or lines, blood can be returned to the patient by pressing “Return Blood”. Do NOT return blood if clotting is evident or the “Filter is Clotting” alarm has sounded.
Follow the instructions on the screen exactly: o Clamp all lines and the vascath. o Using a dressing pack and ANTT disconnect access and return lines. o Flush, hep-lock (except in HIT patients), cap and label the vascath. o Select “Unload” note the fluid removal on the treatment complete screen. o Discard the set, calcium syringe and line as per body fluid and drug disposal
protocol. o Document the time and details on the haemofilter observations chart.
Guideline 404FM.2 8 of 15 Uncontrolled if printed
Change Set: Proceed as per End Treatment; however after disconnecting the patient, re-load a new set, continue the same treatment and proceed as per “Connection” on page 3.
TROUBLE SHOOTING
Please see attached trouble shooting flow sheets for details.
Metabolic acidosis
Most patients in renal failure will have a degree of metabolic acidosis prior to commencing CVVHDF; this should improve with treatment over a period of up to 2 to 4 hours. If there has been no improvement OR the patient is profoundly acidotic on commencement of treatment, consider:
1) Increase the blood pump speed to deliver more citrate to the patient. Each citrate molecule metabolises to 3 bicarbonate ions which will act as a buffer.
2) If there a problem with the lactate or solute clearance, increase the replacement rate to 2.2 litres. This will deliver more bicarbonate to the patient, increase the convection, and increase the clearance of medium and large molecules, increase the solute drag, and increases haemofiltration. NB. Monitor electrolyte balance.
3) If there is no problem with lactate or solute clearance, reduce the dialysate flow by 50%. This will clear less citrate, so allow more citrate to reach the patient. This will however reduce molecule clearance, again monitor electrolyte balance.
4) Give systemic sodium bicarbonate to the patient.
Metabolic alkalosis
Consider:
1) Double baseline dialysate flow rate, clears more citrate, so less citrate therefore bicarbonate will reach the patient. This will increase the solute clearance, monitor electrolyte balance.
2) Reduce the blood pump speed to reduce the amount of citrate to the patient.
These changes may affect the solute clearance and filter life, and should not be undertaken without checking with the shift leader or ICU consultant.
What should I do to increase solute clearance?
Small molecules such as urea and potassium will respond to moving the patient up to the next weight bracket, this will increase diffusion.
Larger molecules such as vitamin B12, beta 2 microglobulin, and septic mediators, will respond to increasing the replacement rate, this will increase convection.
What if the patient’s calcium compensation is high?
There are many reasons for increased calcium requirements, however if the calcium compensation is above 150%, the patient ionised calcium is below 1.0 and the calcium ratio is greater than 2.5, this could indicate citrate accumulation. Citrate accumulation occurs when the citrate is not metabolised by the kidneys, skeletal muscle and liver, therefore the chelated calcium is not released back into the patient’s circulation.
The primary concern in this case is to further supplement the patient’s calcium level, and to reduce the citrate load to the patient.
Please see attached trouble shooting flow sheets for details.
Guideline 404FM.2 9 of 15 Uncontrolled if printed
Solute Clearance
Increasing solute clearance depends on the size of the molecule to be cleared.
Small molecules are cleared through diffusion; medium and larger molecules are cleared through
convection.
Abass M (2015), Kamc crrt training - Prismaflex CRRT Medical Overview February 2015,
[Online], https://www.slideshare.net/mobile/MhabbassAbbass/kamc-crrt-training?qid=4d49c6d5-
c46f-437a-960a-ecd93a3e4c1d&v=&b=&from_search=4 (restricted access)
• Increases diffusion
• Increases clearance of small molecules (urea, creataine, potassium and citrate).
• Increases hemodialysis
Moving the patient up to the next weight bracket
• Increases convection
• Increases clearance of medium and large molecules
• Increases solute drag
• Increases hemofiltration
Increasing the replacement rate
Guideline 404FM.2 10 of 15 Uncontrolled if printed
What happens when the patient weight bracket is changed?
Number of weight brackets moved up
Weight (kg)
Blood flow (ml/min)
Dialysate (ml/hr)
Replacement post-filter (ml/hr)
Actual treatment dose achieved (ml/kg/hr). Effluent dose – 15% down time.
Citrate load
Starting point
70 120 1200 500 35 11.6
1 70 ↑130 ↑1300 500 38 12.8
Gives more citrate to the patient, which will metabolise to release 3 bicarbonate molecules per calcium citrate complex. This will help to ↓ pH
↑ Citrate clearance and ↑solute clearance. Will work well for removing Ur Cr and K, but won’t help ↓ pH as much
2 70 ↑140 ↑1400 500 40 14
Gives even more citrate to the patient, which will metabolise to release 3 bicarbonate molecules per calcium citrate complex. This will help to ↓ pH
Further ↑ citrate clearance and ↑solute clearance. Will work well for removing Ur Cr and K, but won’t help adjust pH as much
3 70 150 1500 600 43 14.9
4 70 160 1600 700 47 15.8
5 70 170 1700 800 51 16.8
6 70 180 1800 1000 56 17.5
Although more citrate is infused, a greater amount of the citrate calcium complex is excreted via
the dialysate, this is demonstrated by the calcium syringe rate increasing to compensate.
Guideline 404FM.2 11 of 15 Uncontrolled if printed
What happens when I increase just the blood pump speed?
Weight (kg)
Blood flow (ml/min)
Pre-blood pump (ml/min)
Dialysate (ml/min)
Replacement (ml/min)
Actual treatment dose (ml/kg/hr)
Citrate load
70 120 1200 1200 500 35 11.6
70 ↑140 1400 1200 500 38 ↑14.4
70 ↑160 1600 1200 500 40 ↑17.6
70 ↑180 1800 1200 500 42 ↑20.2
This has the effect of increasing the amount of citrate getting to the patient which enables the
citrate complex to be broken down to release the calcium and bicarbonate.
You can see changes in the citrate load and effluent dose by pressing the “View Changes” button
on the screen that appears when you change the flow rates.
Baxter Prismaflex Learning Website, https://prismaflex71.baxter.semcon.com/en-gb/
Guideline 404FM.2 12 of 15 Uncontrolled if printed
Metabolic Acidosis with Calcium Ratio <2.5 and Patient Ionised Calcium >1
No improvement to acidosis on standard filter settings, despite reversible causes being
addressed; discuss with ICU consultant and shift leader and consider:
Increase blood pump speed by 20 ml
This delivers more citrate to the patient.
(Do NOT move up patient weight bracket.)
Is improvement shown
after 1 hour?
Yes No
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
Max 3 times
or 200 ml
whichever is
less
If the blood pump speed has
been increased 3 times, or
reached 200 ml with no
improvement
Reduce dialysate flow by 50%
This clears less citrate, so allows more
citrate to reach the patient. N.B This
will also reduce the solute clearance,
so watch K+ etc.
Is there a lactate or solute
clearance problem? Yes No
Increase replacement flow to 2.2 litres max.
This will deliver more bicarbonate to the patient
and increase solute clearance. This can increase
the chance of clotting in the return line, be alert
for alarms.
Yes Yes
No
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
No
Each citrate molecule metabolises to release 3 bicarbonate ions; this is why we aim to get more citrate to the patient.
These interventions will have differing effects on solute clearance, and the potential for citrate toxicity. Please remember
hourly post-filter ionised calcium and patient ionised calcium checks until these values are within normal limits.
Watch for signs of citrate toxicity: ↓ionised Ca++
(below 1.0), ↑ calcium compensation, calcium ratio >2.5
Ensure the shift leader and ICU consultant remain informed of the outcomes to any changes made.
Is improvement shown
after 1 hour?
Is improvement shown
after 1 hour?
Consider systemic sodium
bicarbonate infusion
Consider systemic sodium
bicarbonate infusion
OR OR
When pH is back in range, reduce
the replacement rate by 500 ml until
baseline rate is achieved.
In severe acidosis with marked electrolyte derangement, consider moving up 2 weight brackets MAX. If pH is slow to correct, increase the blood pump speed.
Guideline 404FM.2 13 of 15 Uncontrolled if printed
Calcium Ratio >2.5 and Patient Ionised Calcium <1
If calcium ratio is above 2.5 and the patient ionised calcium falls below 1.0 despite calcium
correction; discuss with ICU consultant and shift leader and consider:
Decrease blood pump speed by 20 ml increments
until calcium ratio and ionised calcium correct, or
blood pump speed reduced to 100 ml.
This reduces the citrate load to the patient.
Is improvement shown
after 1 hour?
Yes No
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
If the blood pump speed has
been decreased, or reached
100 ml with no improvement
Aim post filter Ca+ of 0.4 – 0.5 mmol/L.
Decrease citrate dose in 0.2 mmol/L increments until this is achieved.
If total effluent dose falls below 30 ml/kg/hr increase the replacement flow until a dose of 30 ml/kg.hr is achieved.
Post filter Ca+ can be checked straight after the
changes are made.
Is there citrate accumulation
with acidosis? Yes No
Increase replacement flow to 2.2 litres max.
This will increase hemofiltration and solute
clearance. This can increase the chance of
clotting in the return line, be alert for alarms.
Yes Yes
No
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
No
These interventions will have differing effects on solute clearance. Please remember hourly post-filter ionised calcium
and patient ionised calcium checks until these values are within normal limits.
Ensure the shift leader and ICU consultant remain informed of the outcomes to any changes made.
Is improvement shown after post filter Ca+ is corrected?
Is improvement shown
after 1 hour?
Double baseline dialysate flow
This will increase citrate clearance, and
solute clearance, watch electrolyte balance.
Consider giving
additional IV calcium
supliment patient
calcium level.
Guideline 404FM.2 14 of 15 Uncontrolled if printed
Metabolic Alkalosis pH >7.45 with B.E >+5
These changes may affect solute clearance and filter life, discuss any changes with the shift
leader or the ICU consultant.
Rule out and treat underlying causes
(i.e. prolonged vomiting, diuretic overuse,
hypovolaemia and hypokalaemia)
Is the alkalosis thought to be
due to excess citrate
accumulation?
Check ionised Ca+ and Ca ratio.
Double the baseline dialysate rate.
This will clear more citrate; it will also clear
more solutes, monitor electrolyte balance.
Is improvement shown
after 2 hours?
Is improvement shown after 4 - 6 hours
of standard rate haemofiltration?
No Yes
Continue current settings
review hourly until calcium
readings are stable on 2
consecutive readings
Yes
Yes No
No
Reduce blood pump speed.
This will reduce the citrate load to the
patient, and consequently reduce the buffer
delivered.
These interventions will have differing effects on solute clearance. Please remember hourly post-filter ionised calcium
and patient ionised calcium checks until these values are within normal limits.
Ensure the shift leader and ICU consultant remain informed of the outcomes to any changes made.
Guideline 404FM.2 15 of 15 Uncontrolled if printed
Title of Guideline Continuous Renal Replacement Therapy (CRRT) using Citrate
Guideline Number 404FM
Version 2 Effective Date July 2018 Review Date July 2021 Original Version Published February 2015 Approvals: Formulary Management Group 22nd October 2014 Clinical Guidelines Subgroup 25
th July 2018
Author/s Lucy Bull (Revised by Tracy Hadcroft May 2018)
SDU(s)/Department(s) responsible for updating the guideline
Critical Care
Uploaded to Intranet 30th July 2018
Buckinghamshire Healthcare NHS Trust