Download Fluid Management for Patients with Known Renal Disorders

Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Short Title:
Fluid Management in Patients with Known Renal Disorders
Full Title:
Date of production/Last revision:
Guideline for Management of Fluids in Children and Young People with
Known Renal Disorders
June 2008
Explicit definition of patient group
to which it applies:
This guideline applies to all children and young people under the age of 19
years.
Name of contact author
Dr Farida Hussain, Consultant Paediatric Nephrologist
Ext:
June 2011
Revision Date
This guideline has been registered with the Trust. However, clinical guidelines are 'guidelines' only. The interpretation
and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a
senior colleague or expert. Caution is advised when using guidelines after the review date.
Contents
Page
Introduction
2
Summary of organization
3
Patients with chronic kidney disease:
Oligo-anuria
Polyuria
4
Tubulopathies
5
Nephrogenic diabetes insipidus
6
Acute renal impairment
7
Appendix
Composition of fluids
Chronic kidney disease categories
Normal ‘maintenance’ fluid requirements
8
Farida Hussain
Page 1 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Introduction
The aim of this guideline is to provide guidance in management of intravenous fluids in
patients with known renal disease who are nil by mouth (for whatever reason). This includes
patients with chronic renal impairment, acute renal failure and tubulopathies. The commonest
situation where this arises is in the peri-operative time period, but is also applicable if the
patient is nil by mouth for other reasons e.g. unable to tolerate oral fluids due to severe
gastroenteritis.
For ALL patients undergoing surgery, good liaison with the surgeons and
anaesthetists is imperative.

Discussion with the surgeons may limit the length of time that the patient requires to
be nil by mouth (for fluids +/- medicines) which will help with the overall management
of these patients.

Co-ordinate to place the child first on the operating list if possible.

Wherever possible (e.g. routine surgery) the problem should be anticipated and fluids
calculated before the patient is admitted for surgery. This is especially important in
certain groups of patients (e.g. patients with cystinosis) where preparation of the i.v.
fluids need to be checked by pharmacy and can cause delays.
The following is intended to be used as a guideline only. All cases should be
discussed with the consultant paediatric nephrologist on-call.
For all patients, on-going assessment of their clinical state and regular review of weight, along
with regular blood tests are imperative (the frequency of which should be discussed with the
consultant on-call) as this may alter the fluid regime that needs to be prescribed.
Farida Hussain
Page 2 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Summary of Organisation
Planning for elective procedures
Referral letter from Paediatric nephrology to surgical team (with a copy in the notes). The
surgical team should ensure the relevant anaesthetist is also sent a copy of the letter. The
letter should include:
 Current weight
 Height
 BP
 Estimated 24 hour urine output
 Current recommended fluid intake (restriction / target)
 Current medication
 Current electrolyte results
For all procedures:
Pre-op assessment (by surgical team):
 24 hour urine output estimation
 current fluid intake (restriction or target)
 current medications (inc. mineral supplements)
 recent U&E results
 liaison w surgeons & anaesthetists (&PICU if necessary)
 prescribe fluids if requires pharmacy input
At time of operation:
 confirm above details
 examine patient paying particular attention to:
o State of hydration
o Weight – compare with previous weights
o Height
o Blood pressure
 Prescribe fluids if not already done
Post-op monitoring of patient: (frequency to be agreed)
 Clinical status
 Strict fluid input / output charts
 Weight
 U&E’s - (should include full renal profile: includes HCO3-, Ca and PO4 frequency
decided by consultant
 An immediate post-op sample should be sent on all patients
 Liaise with surgeons re: when can restart oral / gastrostomy feeds +/- medications
Farida Hussain
Page 3 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Patients with Chronic Kidney Disease
The management pre, peri, and post-operatively, of ALL of these patients should be
discussed with the paediatric nephrologists on-call, even if the patient is admitted under a
different team (e.g. surgical team).
Depending on the patient’s diagnosis, and current CKD staging (See appendix), their
management will be different, and an up-to-date knowledge of their current estimated 24 hour
urine output, current fluid requirements and current medications (as outlined in the planning
stage) allows a decision as to which of the following categories to place the patient.
a) Oligo-anuric
These patients usually have severe chronic renal insufficiency
(typically GFR < 15mls/min/1.73m2)
Pre-renal transplant
This is a very specific clinical situation, as the patients need to be well hydrated pre-op.
Please refer to separate renal transplant guidelines
Other situations
 If the patient has a set fluid restriction at home (provided that they are not either
dehydrated or fluid overloaded), this can be set as a 24 hour fluid requirement.

Fluid prescription – this will depend on recent blood results, but in general 5%
dextrose 0.45% saline is used.

For most oligo/anuric patients, potassium should NOT be added to i.v fluids

Regular monitoring of both clinical and biochemical status is required and fluids
adjusted accordingly. (typically this involves blood test monitoring 12 hourly initially)

If no fluid limits have been set, the patient can be managed safely with a regime of
insensible losses + urine output
Insensible losses are calculated as: 400mls/m2/day).
Body Surface Area calculated using the equation: √ (ht in cm x wt in kg / 3600).
b) Polyuric patients
These patients may produce large volumes of urine, and are also typically salt-losers, and are
therefore at high risk of dehydration without adequate fluid replacement.
Pre- renal transplant
This is a very specific clinical situation, as the patients need to be well hydrated pre-op
Please refer to separate renal transplant guidelines
Other situations
 Pre-operative calculate current daily fluid intake
 Review recent U&E’s blood results
 Calculate current sodium intake (if on supplements)
 Check urinary sodium
Farida Hussain
Page 4 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Tubulopathies
Fanconi syndrome (e.g. cystinosis)
Cystinosis is an autosomal recessive disorder characterized by defective lysosomal cystine
transport, leading to excessive intracellular cystine accumulation. This affects predominantly
the proximal tubule, leading to a severe Fanconi’s syndrome (hypophosphataemia,
aminoaciduria, glycosuria and acidosis). They also have a high fluid requirement due to
polyuria.
Pre-op
 Calculate the current fluid intake that the patient requires
 Calculate daily sodium, potassium and bicarbonate requirements from medications.
 Choose appropriate fluid, and calculate how much potassium chloride and sodium
bicarbonate need to be added to each bag.
o Please note that these patients often have very high potassium
requirements.
 Addition of potassium to i.v fluid bags is restricted to certain wards
and therefore it may be necessary for the fluids to be made up in
pharmacy – these should be written up in advance to avoid any
delays
 all calculations should be checked with responsible nurse
Example:
A 15kg child with cystinosis usually takes 1.5 litres/day.
He is on 5mmol tds of potassium acid phosphate and 5mls tds of polycitra LC (1mmol /ml K+,
1mmol/ml Na+, 2mmol/ml of bicarbonate)
Each day, he therefore requires:
 1500mls fluid
 total of 30mmol of K+
 total of 30 mmol of bicarbonate
 total of 45 mmol of Na+ (30mmol = ‘maintenance’ :(2mmol/kg) + 15 mmol
supplements).
It would be appropriate to prescribe 4% Dex/ 0.18% Saline with 10mmol K+, 10mmol
Bicarbonate – added to each 500 ml bag, to run at 65mls/hr (Rounded up from 62.5mls/hr).
Fluids should be commenced as soon as the patient is nil by mouth, and not wait until the
patient is in theatre – as there is a risk of dehydration in this time.
Post-op
Fluids continued with
 regular clinical review (including repeating patient weight if necessary)
 regular blood monitoring ((U&E should be a full renal profile - includes HCO3-, Ca
and PO4 and is typically 8 hourly)
 with adjustment to fluids (rate +/- composition) if necessary.
Liaise with surgeons about re-starting medications and using NG tube or gastrostomy (if
patient has one) as soon as possible, as this will aid management.
Farida Hussain
Page 5 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Nephrogenic Diabetes Insipidus (NDI)
NDI is the inability of the kidney to concentrate urine in response to arginine vasopressin,
leading to polyuria and polydipsia. In contrast to the conditions mentioned already, these
patients produce very dilute urine and ‘hold on’ to sodium. Patients are normally able to ‘selfregulate’ their sodium concentration, provided they have access to free water and are able to
tolerate this.
If they are kept nil by mouth, their clinical status can change rapidly and this is reflected in the
level of monitoring suggested for them post-operatively.
 Admission to PICU / HDU electively should be considered for all NDI patients who
require to be kept NBM post-operatively
 Discussion with the surgeons as to when the earliest time water can be given orally or
via gastrostomy should occur, as this will ease management.
Pre-op

Knowledge of current total daily fluid intake – allows calculation of hourly fluid
requirement.

Fluids should be commenced as soon as the patient is nil by mouth

Calculate the ‘normal’ maintenance volume for 24 hours the patient would receive for
their weight. This volume should be given as 4% dextrose / 0.18% Saline

Then calculate what ‘extra’ fluid they normally take per day. This volume should be
given as 5% dextrose.

The 2 fluids should be run simultaneously (i.e. 2 iVAC pumps will be required)
Example
A 10 kg child with NDI who normally takes 3 litres / day
‘maintenance’ = 100mls/kg = 1 litre (41mls/hr of 4% dextrose / 0.18% saline)
‘extra’ = 2 litres (83mls/hr of 5% dextrose)
As these patients run the risk of hypernatraemic dehydration, close monitoring is required
including:




Hourly input/ output (weighing nappies is usually sufficient)
Regular weights (up to 6 hourly if NBM)
Regular biochemistry monitoring including BM’s (6 hourly initially – as long as initial
post-op bloods satisfactory)
Bloods samples should be requested as urgent, and results should be chased up and
entered onto a results flow sheet)
If there is any evidence of worsening hypernatraemia, weight loss or negative fluid
balance discuss with consultant. The ratio of fluids being given may need to change and
the rate of administration may need to be altered (if the rate requires changing, it will usually
involve increasing the rate of 5% dextrose alone)
If there is evidence of hypokalaemia, potassium should be added –to the ‘maintenance’ (4%
dex/0.18% Saline) fluids.
If there is evidence of hyperglycaemia, this should be controlled, as this may drive the urine
output further – discuss with consultant if rising BM or BM>15 or glycosuria.
Farida Hussain
Page 6 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
As soon as the patient can tolerate enteral fluids (discuss with surgeon if post-op, to see if
clear fluids allowed as soon as possible) allow them to take water orally / via NG / via
gastrostomy, and reduce the iv fluid rate accordingly (as long as clinically stable)
A decision as to which fluid rate to reduce will depend on factors including: current sodium
and glucose levels.
Patients with Acute Renal Failure +/- Acute Glomerulonephritis
These patients usually present with oliguria or anuric. ALL of these patients should be
referred to paediatric nephrology

Many patients will be given a set fluid restriction by the consultant paediatric
nephrologists on-call

Fluid prescription – this will depend on recent blood results, but in general 5%
dextrose 0.45% saline is used.

For most oligo/anuric patients, potassium should NOT be added to i.v fluids

Regular monitoring of both clinical and biochemical status is required and fluids
adjusted accordingly. (typically this involves blood test monitoring 8 –12 hourly)

If no fluid limits have been set, the patient can be managed safely with a regime of
insensible losses + urine output
Insensible losses are calculated as: 400mls/m 2/day.
Body Surface Area calculated using the equation: √ (ht in cm x wt in kg / 3600).
Farida Hussain
Page 7 of 8
June 2008
Paediatric Guideline
Renal 6.6
Fluids Management in Patients with Known Renal Disorders
Appendix
Composition of Commonly Used Intravenous Fluids:
0.9% Saline
0.9% Saline + 5% dextrose
0.45% saline + 5% dextrose
0.18% saline + 4% dextrose
5% dextrose
Na+
(mmol/l)
156
156
78
30
-
Cl(mmol/l)
156
156
78
30
-
K+
(mmol/l)
-
Glucose
(g/100ml)
5
5
4
5
Note: 0.45% solution alone is a hypotonic solution and its use is severely restricted.
Chronic Kidney Disease Categories
CKD stage
1
2
3
4
5
Description
Kidney damage with
Normal or ↑ GFR
Kidney damage with
Mild ↓ GFR
Moderate ↓ GFR
Severe ↓ GFR
Kidney failure
GFR (ml/min/1.73m2)
≥90
60 – 89
30 – 59
15 – 29
< 15
(or dialysis)
“Normal’ Maintenance Fluid requirements per 24 hours



100mls/kg– for the 1st 10kg
50mls/kg– for the 2nd 10kg
20mls/kg thereafter
Insensible Losses
These are estimated on the basis of body surface area as 400mls/m 2/day.
Body Surface Area is estimated using the equation: √ (height [cm] x wt [kg] / 3600)
Farida Hussain
Page 8 of 8
June 2008