fluid & electrolytes (dr acharya)
TRANSCRIPT
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
1/69
1
Fluid and electrolyte therapy
Dr Ashoka Acharya
Consultant PaediatricsWarwick hospital
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
2/69
2
Dehydration
Abnormal fluid losses overcoming renalcompensating mechanisms
Main aim of compensation ismaintaining plasma volume and BP atall cost
Loss of homeostasishypovolaemicshock
Principal causes: diarrhoea and DKA
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
3/69
3
Definition
Parenteral or oral fluid therapy
Maintain/restore volume/composition of
body fluids
Takes account of corrective
physiological mechanisms
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
4/69
4
Fluid therapy: Goal
Achieve normal intracellular and
extracellular chemical environment
Thereby optimise cell and organfunction
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
5/69
5
Factors determining requirements
Maintenance fluid: replaces usual
losses of fluid and electrolytes
Deficit replacement fluid: designed toreplace abnormal losses due to disease
Supplemental fluid: replaces measured
or estimated continuing abnormallosses
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
6/69
6
Factors determining requirements
Each component is calculated
separately
Fluid therapy often based on grossestimates. Deficit often overestimated.
Repeated clinical reassessment and
adjustment needed
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
7/69
7
Maintenance fluid
Directly related to metabolic rate
endogenous water production
urinary solute excretion,
heat production- 25% lost through
insensible water loss)
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
8/69
8
Maintenance therapy
Generally 100ml per 100 calories used
Urine: obligatory loss = 65 ml
Insensible water loss = 35 ml
Sweating =23 ml
pulmonary =12 ml
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
9/69
9
Maintenance therapy: increased
requirements Increased activity (30%)
Fever (1C increases by 12%)
Dry environment
Hyperventilation
ELBW- transcutaneous losses 100-200ml/kg/day
Overhead heaters, phototherapy units
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
10/69
10
Maintenance fluid-decreased
requirements Comatose
Hypothermia
Highly humidified atmospheres
Humidified ventilator circuits
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
11/69
11
Maintenance fluid: increased
renal losses High solute load (DM, Mannitol, high
protein diets)
ADH insufficiency
Central
Nephrogenic Primary
Secondary: sickle cell, obstructive uropathy, chronic
PN, reflux nehropathy, hypokalemia, hypercalcemia,
drugs, psychogenic polydipsia
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
12/69
12
Maintenance fluid: decreased
urinary losses SIADH
Renal failure
Replace insensible water loss +urine
output ml/ml with free water
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
13/69
13
Maintenance sodium needs
Increased: CF, salt losing nephropathy,
chronic PN, obstructive uropathy,
diuretics, fistulas, diversions, NGdrainage
Decreased: Hepatic failure, cardiac
failure, renal failure, nephrotic syndrome
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
14/69
14
Maintenance potassium needs
Increased: Chronic renal disease,
gastric and intestinal drainage, chronic
diuretics, laxative abuse Decreased or nil: Acute renal failure,
adrenal insufficiency, severe metabolic
acidosis
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
15/69
15
Normal maintenance
requirements (holiday and segarWt (kg) H20(ml/k
g/dy)Na(mmol/kg/dy)
K(mmol/kg/dy)
Energy(kcal/Kg/dy)
First 10kg
100 2-4 1.5-2.5 100
Second10 kg
50 1-2 0.5-1.5 75
Subsequent kg
20 0.5-1 0.2-0.7 30
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
16/69
16
Maintenance fluids: route
Oral or parenteral
Calories: usually as 5% dextrose
TPN
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
17/69
17
Deficit Therapy: factors affecting
Oral or parenteral intake
Pathologic body losses
Physiologic body losses
compensatory attempts to modify
volume and composition
Net effect- Deficits from different causes
often similar in magnitude and
composition
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
18/69
18
Infant: moderately severe
dehydrationCondition H2O
(ml)Nammol
Kmmol
Clmmol
D and VIsonatremic 100-200 8-10 8-10 8-10Hypernatremic
100-200 2-4 0-4 -2 to 6
Hyponatremic
100-200 10-12 8-10 10-12
Pyloricstenosis
100-200 8-10 10-12 10-12
DKA 100-200 8-10 5-7 6-8
Fasting andthirsting
100-200 5-7 1-2 4-6
Per k bod wei ht
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
19/69
19
Deficit therapy
Severity: Magnitude and rapidity
Estimated from recent weight or clinical
features
Type: Relative loss of water and
electrolytes mainly sodium
pathophysiology
therapy
prognosis
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
20/69
20
Deficit therapy: Types
Isotonic: sodium 130-150 mmol/l, no
fluid shifts, 80% of cases
Hypotonic: sodium 150 mmol/l, ICF to
ECF, 10% cases
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
21/69
21
Deficit Therapy:types and history
D and V for days, good intake, low salt
Cholera, bacillary dysentery
High fever, poor intake
Infant with NDI, poor water intake
Intake of dilute milk formula
Intake of boiled semiskimmed milk
wrongly prepared ORS
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
22/69
22
Assessment of deficit severity
Signs &symptoms
Mild dehydration Moderatedehydration
Severedehydration
Body weightloss(%)
3-5% 6-9% 10%or more
General app,infant
Alert, restless Thirsty, restless/lethargic/irritable
Lethargic/comatoseFloppy,cold,sweaty
Older child- Thirsty, alert,restless
Thirsty, alert,posturalhypotension
Lethargic,cold,sweaty,cyanosed,wrinkle
d skin, musclecramps
Radial pulse Normal Rapid and weak Rapid,thready/impalpable
Respiration Normal Deep Deep and rapid
Anterior fontanel Normal Sunken Very sunken
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
23/69
23
Assessment of severity: contd
Systolic BP Normal Normal/orthstatichypotension
Low/unrecordable
Skin elasticity Retractsimmediately
Retracts slowly Retracts veryslowly
Eyes Normal Sunken Grossly sunken
Tears Present Absent/reduced absent
Mucosa Moist Dry Very dry
Urine Normal Reduced and dark Anuria/severeoliguria
CRT Normal +/- 2 sec >3 sec
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
24/69
24
Calculation of deficit fluid
Percentage dehydration x wt in kg x 10=
ml of fluid
eg: 7% dehydration of infant weighing10 kgs = 7x10x10=700 ml
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
25/69
25
Clinical features
Signs represent depletion of ECF
Plasma: tachycardia, fall of BP, postural
hypotension, cool extremities, increasedCRT, decreased urine
Interstitial fluid: Tenting of skin
Transcellular fluid: dry mouth, sunken eyes,decreased tears, sunken fontanel
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
26/69
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
27/69
27
Signs V's type of deficit
Hyponatremic: increased severity of
signs for amount of fluid loss
Hypernatremic: Less signs, irritable,hypertonic, hyperreflexic, warm
extremities, doughy skin
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
28/69
28
Lab tests
FBC: Increased Hb, PCV
Serum Na: type of dehydration
serum K: gut loss, acidosis; needs ECG monitoring Serum HCO3: acidosis- D&V, DKA: alkalosis-Pyloric
stenosis, NG drainage
Serum chloride: changes with Na, chloride diarrhea
Urea/creatinine: elevated with decrease in GFR, maybe normal!
Urine: infection screen, specific gravity, electrolytes
stool: culture, electrolytes
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
29/69
29
Treatment
Oral therapy: mild to moderatedehydration
Parenteral therapy: severe dehydration
Persistent vomiting
Refusal of oral intake
Abdominal distension
No caregiver to give close attention
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
30/69
30
Stages of treatment
Initial therapy: expand ECF volume
Subsequent therapy: replace
deficit/maintenance/ongoing losses
Final therapy: Return to normal
composition/establish oral feeds/correct
potassium deficit
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
31/69
31
Commonly available crystalloids:
isotonicFluids Na (mmol/l) K (mmol/l) Cl (mmol/l) Energy(kcal/l)
other
saline0.9% 150 0 150 0 0
saline0.45%dextrose
2.5%
75 0 75 100 0
Saline
0.18%
dextrose
4%,KCl
20mmol/lit
30 20 30 160 0
Dextrose
5%
0 0 0 200 0
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
32/69
32
Isotonic crystalloid fluids
Fluid Na K Cl Energy Other
Saline
0.18%
dextrose
4%
30 0 30 160 0
Hartmanns
solution
131 5 111 0 lactate
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
33/69
33
Hypertonic crystalloids
Fluid Na K Cl Energy Other
Saline
0.45%dextrose
5%
75 0 75 200 0
Dextrose
10%
0 0 0 400 0
Saline0.18%
dextrose
10%
30 0 30 400 0
Dextrose
20%
0 0 0 800 0
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
34/69
34
Colloid fluids
Fluids Na K Ca Duration
of action
comments
Albumin
4.5%
150 1 0 6 Protein buffers
Gelofusine 154
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
35/69
35
Initial therapy
Normal saline or Hartmans solution
regardless of type of deficit
20 ml/kg rapid bolus, repeat if needed IV, intraosseous line
Never use hyponatremic fluids
Adequate crystalloid dose better than colloid No potassium till urine output established
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
36/69
36
Subsequent therapy
Calculate over 8 hour intervals
Deficit replaced over 24 hours but can
be done over 8 to 12 hours exceptHYPERNATREMIA
Early K+ replacement after urine output
Maximum K+, 40 mmol/l (ITU 80mmol/l)
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
37/69
37
Isonatremic dehydration
Deficit plus maintenance plus ongoing lossescalculated
Use 0.45%saline with 2.5% or 5% dextrosefor subsequent therapy
Give 50% in first 8 hours and remaining over16 hours
Subtract boluses from total fluid Assess clinical state regularly and modify if
needed
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
38/69
38
Hyponatremic dehydration
Extra Na deficit (mmol/l)=desired Na-
actual Na x 0.6 x Wt kgs
Manage as for isonatremic dehydrationbut replace deficit Na over 12-24 hours
Raise serum Na by 10 mmol/l/day
If Na
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
39/69
39
Hypernatremic dehydration:
complications Cerebral haemorrhage, thrombosis,
subdural effusion- permanent handicap,
renal vein thrombosis During treatment- cerebral oedema,
seizures, hypocalcemia
High mortality if Serum Na >160mmol/l
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
40/69
40
Hypernatremic dehydration
Always use isonatremic boluses
Slow correction of deficit over 48 to 72 hours
Aim to decrease serum Na by 10 mmol/l/day Use 0.18saline or 0.45% saline with dextrose
for subsequent therapy
Seizures: 3% saline, mannitol,hyperventilation, calcium gluconate
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
41/69
41
Supplemental fluids
Consider composition of fluid lost
D&V: 0.45% saline
Cholera:0.9% saline
NG tube aspiration: 0.45 to 0.9% saline
plus potassium
Gut losses: same
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
42/69
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
43/69
43
Assessment of response
Appearance, activity
Skin turgor
BP Intake/output chart
U&E, glucose
blood gas CVP monitoring
Eyeballs, tears
CRT
Weight Urine Specific
gravity
Urine output ECG monitoring
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
44/69
44
Oral rehydration therapy
Mild to moderate dehydration
Types of ORS: high sodium- 90mmol/l,
low Na- 50 mmol/l
Glucose facilitated sodium absorption,
sucrose less effective, rice based
effective
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
45/69
45
ORS
Use 50ml/kg in mild and 100ml/kg inmoderate dehydration.
Give over 4 hours. Allow breast feeds andformula after rehydration. Reassess regularly.Small frequent feeds decrease vomiting.Consider NG tube.
Maintenance with 100ml/kg/day till diarrhoeastops
For on going losses add 10-15ml/kg/hr
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
46/69
46
Hyponatremia: sodium depletion
Renal losses: Preterm, ATN, Diuretics,
mineralocorticoid deficiency, RTA
Extra renal loss: D&V, Burns, ascites,pleural effusion,csf drainage, NG
drainage, CF
Nutritional deficits: Inadequate Na inTPN, oral intake
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
47/69
47
Hyponatremia: water excess
SIADH
Glucocotricoid deficiency
Hypothyroidism
Excess parenteral fluid
Psychogenic polydipsia
Tap water enema
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
48/69
48
Hyponatremia: excess Na and
water
Nephrotic syndrome
Cirrhosis
Cardiac failure
Acute and chronic renal failure
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
49/69
49
Hyponatremia: asymptomatic
Water Excess: (urinary Na usually >20
mmol/l) fluid restriction, may be needed
for days Salt deficiency: (urinary Na
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
50/69
50
Hypernatremia: sodium excess
Improperly mixed ORS or formula
Accidental or deliberate swap of salt for
sugar in feeds Excess Bicarb during resus
Hypernatremic enemas
Drugs: penicillin, gaviscon
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
51/69
51
Hypernatremia: water deficit
Diabetes insipidus
Solute diuresis
D&V
Inadequate breast feeds
Intentional water with holding
Insensible loss in prematures
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
52/69
52
Hypernatremia: treatment
Salt poisoning: peritoneal dialysis
Phenobarbitone for seizures
Inotropes for heart failure
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
53/69
53
Hypokalemia: causes
Diarrhoea
Alkalosis
Volume depletion Primary hyperaldosteronism,cushing syn,
thyrotoxicosis
Diuretic abuse DKA
Bartters syndrome
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
54/69
54
Hypokalemia: consequences
Cardiac: flat T wave and prolonged QTinterval
Orthostatic hypotension, tetany, hypotonia,muscle weakness, death from resp failure
Paralytic ileus, gastric distension
Failure to thrive
Rhabdomyolysis Nephrosclerosis and interstitial fibrosis:
polyuria
alkalosis
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
55/69
55
Hypokalemia: treatment
Replacement potassium orally or
parenterally
3 mmol/kg/day in Barttersyn/indomethacin
Up to 10 mmol/kg/day in
RTA/hyperaldosteronism
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
56/69
56
Hyperkalemia: causes
Renal failure
Acidosis
Adrenal insufficiency
Cell lysis (trauma, surgery, tumour lysis)
Excessive intake
Sampling error!
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
57/69
57
Hyperkalemia: consequences
Paresthesias, flaccid paralysis
Tall T waves, increased P-R interval,
wide QRS complex, VF
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
58/69
58
Hyperkalemia:management
If cardiac rhythm affected give calcium 1mmol/kg iv/specific anti arrhythmic drug
If normal rhythm, give nebulised salbutamol2.5 to 5 mg. Check K and pH.
If falling K- give calcium resonium 1g/kg po orpr- plan dialysis if needed
If still high (6.5 or more) give dextroseinfusion 0.5g/kg/hr and iv insulin infusion,0.05units/kg/hr if pH 7.35 give sodium bicarbonate 2.5
mmol/kg iv
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
59/69
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
60/69
60
Hypercalcemia
Hyperparathyroidism, Hypervitaminosis
D&A, Idiopathic hypercalcemia,
malignancy thiazide diureticabuse,skeletal disorders,immobilisation
Polyuria, polydypsia
Volume expansion with saline,treatment of cause
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
61/69
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
62/69
62
Hypermagnesemia
Usually in renal failure, Addison disease,
toxemia of pregnancy, enemas in megacolon
Drowsiness, coma if levels exceed 10 meq/l.Intra ventricular and atrioventricular
conduction defects at 5 meq/l
IV calcium gluconate rapidly reverses effects
on heart and CNS
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
63/69
63
Case 1
8 week old infant
Weight 4 kgs, poor wt gain in last 4
weeks, Vomiting from 3 weeks of age, now after
most feeds, forceful, not passing urinewell last 24 hours
Moderate dehydration on examination
Na 130, Cl 94, K 2.6, HCo3 29.8
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
64/69
64
Case 1
Maintenance: 100 x 4= 400 ml
On going losses: Ng aspirate volume for volume with normal
saline
Start 0.45% saline dextrose 5% to give 400 ml over 8 hours andremaining 400 ml over 16 hours
Add Kcl 4 mmol/100ml once urine output noted
Monitor weight, urine output, Nasogastric aspirate, blood gas
and electrolytes,ECG.
Once serum K rises to 3.5 decrease Kcl to 2 mmol/100ml Deficit fluid: 10 x10 x4= 400 ml
Once stable, send for surgery
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
65/69
65
Case 2
One year old, 10 Kgs with 2 days of
D&V. Given clear fluids at home. No
urine in last 6 hours. Some fever. Notdrinking ,lethargic last 2 hours.
Severe dehydration on examination
Blood: Na 136, K 2.2, Hco3 8, pH7.35
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
66/69
66
Case 2
Bolus 20 ml/kg- 0.9%saline, repeat if still shocked
Deficit fluid: 15 x10 x10=1500 ml 400ml bolus = 1100ml
Maintenance fluid: 100 x10= 1000 ml
Give 1050ml in 8 hours and 1050 remaining in 16 hours as0.45% saline 5% dextrose
Add Kcl 40 mmol/l after urine output
Monitor ECG, weight, urine output, electrolytes, continuing
losses for replacement
Once rehydrated offer ORS, milk and review fluids
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
67/69
67
Case 3
Four year old weighing 14 Kgs, lethargic,
vomiting, rapid breathing since 12 hours.
Producing urine. Normal stools. Over 2
weeks, since a cold has been drinking a lot,
eating a lot and bed wetting again.
Moderate dehydration
Glucose 30 mmol/l, Na 128 mmol/l, K 4.8mmol/l, HCO3 8 mmol/l, pH 7.28
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
68/69
68
Case 3
Start normal saline infusion, 20 ml/kg over 1 hour
Start insulin infusion 0.05u/kg/hr
0.45 saline+Kcl 20mmol/500 ml, 20 ml/kg over 2ndhour
0.45 saline+KCL or Pot phos 30mmol/l over 10 hours
Maintenance fluid for 36 hours:1000+50x4=1200+600=1800ml
Deficit fluid: 10x10x14= 1400 ml
Correct 50% deficit in first 12 hours
Monitor ECG, glucose, U&E, blood gas, weight, urine output, GCS hourlyto 2 hourly
Change fluid to 0.18 saline 5% dextrose when blood glucose reaches 16 to17 mmol/l. Adjust K and insulin infusion rates as needed. Consider an
Antibiotic.
When blood gas normal, blood glucose stable,patient drinking, givesubcutaneous insulin 0.2 to 0.4 units/kg qds and stop iv infusions.
Start regular insulin dose after another 24 hours
-
8/12/2019 Fluid & Electrolytes (Dr Acharya)
69/69
DKA: complication
Cerebral edema: headache, change in
consciousness,unequal dilated pupil,
vomiting,incontinence,delirium,bradycardia
Reduce iv rate, mannitol 1gm/kg iv,
repeat in 2-4 hours