1

Fluid and electrolyte therapy

Dr Ed Simmonds

Consultant Paediatrics

UHCW

2

Case 1

Four year old weighing 15 Kgs, 24 hour history

of D & V. Looks unwell/dehydrated. Trial of oral

fluids initially not tolerated.

Admitted for management with fluids.

How will you proceed?

3

General principles

Maintenance fluid: replaces usual losses of fluid and electrolytes

Deficit : designed to replace abnormal losses due to disease

Supplemental fluid: replaces measured or estimated continuing abnormal losses (eg loose stools)

4

5

Normal maintenance requirements

First 10kg body weight – 100mls/kg/day 4mls/kg/hour Second 10kg weight 50mls/kg/day 2mls/kg/hour Subsequent weight 20mls/kg/day 1ml/kg/hour

Calculate maintenance requirements

6

100mls/kg x 10 = 1000mls

50mls/kg x 5 = 250mls

Total = 1250mls/24hrs

Prescription 52mls/hr

Dehydration

7

Diarrhoea and vomiting in children under 5

Assessing dehydration slides

Implementing NICE guidance

2009

NICE clinical guideline 84

Symptoms of increasing severity of dehydration

No clinically detectabledehydration

Clinical dehydration Clinical shock

Appears well Appears to be unwell or deteriorating

–

Alert and responsive Altered responsiveness

Decreased level ofconsciousness

Normal urine output Decreased urine output –

Skin colour unchanged Skin colour unchanged Pale or mottled skin

Warm extremities Warm extremities Cold extremities

Signs of increasing severity of dehydrationNo clinically detectabledehydration

Clinical dehydration Clinical shock

Alert and responsive Altered responsiveness

Decreased level of consciousness

Skin colour unchanged Skin colour unchanged Pale or mottled skin

Warm extremities Warm extremities Cold extremities

Eyes not sunken Sunken eyes -

Moist mucous membranes

Dry mucous membranes -

Normal heart rate Tachycardia Tachycardia

Normal breathing pattern

Tachypnoea Tachypnoea

Normal peripheral pulses

Normal peripheral pulses

Weak peripheral pulses

Normal capillary refill time

Normal capillary refill time

Prolonged capillary refill time

Normal skin turgor Reduced skin turgor -

Normal blood pressure Normal blood pressure Hypotension

Dehydration symptoms/signs

Clinical dehydration = 5%

Shock = 10%

11

Calculate deficit

5% dehydration

15kg = 15,000mls

1% = 150mls

5% = 750mls

12

Case 1 - fluid volume prescription

Maintenance plus deficit prescribed over 24 hours

1250 + 750 = 2000mls

83mls/hr

13

Normal maintenance requirementsWt (kg) Na

(mmol/kg/dy) K (mmol/kg/dy)

First 10 kg 2-4 1.5-2.5

Second 10 kg 1-2 0.5-1.5

Subsequent kg

0.5-1 0.2-0.7

Oral or nasogastric fluids

Rehydrate with low osmolarity rehydration solution (ORS)

Hypo-osmolar to prevent osmotic diarrhoea

60mmol Na per litre

20mmol K

60mmol Cl

90mmol Glucose15

Intravenous fluids

0.9% sodium chloride

150mmol/litre Na

0.45% sodium chloride/5% glucose75 mmol /litre Na + 5 grams glucose

0.9% sodium chloride/5% glucose

150mmol/litre Na + 5 grams glucose

17

Case 2

Two year old weighing 12 Kgs.

48 hour history of D & V.

Drowsy, cold hands and feet.

HR 180, RR 40, CRT 4 seconds

How will you proceed?

Management of shock

ABC Oxygen Venous access – bloods for glucose

and renal biochemistry (minimum) 20mls/kg of 0.9% saline Subsequent rehydration

18

Calculations

Maintenance

10 x 100 = 1000

2 x 50 = 100

Total = 1100 Deficit

10% of 12,000 = 1200 Total 2300mls/24hrs = 96mls/hr

0.9% sodium chloride/5% glucose

Electrolyte results

Hyponatraemia <130mmol/litre Normal 135 – 145mmol/litre Hypernatraemia >145mmol

Hypokalaemia <3.5mmol/litre Normal 3.5 – 5.0mmol/litre Hyperkalaemia >5.0mmol/litre

Hypernatraemic dehydration

Cautious fluid replacement Suggested replace deficit over 48hrs Reduce plasma Na by no greater than

0.5mmol/hr

Concern re cerebral oedema

Diabetic ketoacidosis

Cautious fluid replacement If shocked initial bolus 10ml/kg (repeat if

felt necessary). Subtract fluid bolus from deficit

calculations Suggested replace deficit over 48hrs Reduce plasma Na by no greater than 0.5mmol/hr

Potassium

Usually 20mmol/litre for maintenance fluids

When treating dehydration add 20mmol/litre potassium chloride to fluids when happy that passing urine