Fluid & Electrolyte Imbalance

Question 1

Risk factors for dehydration

Answer 1

1. Development - <6months or slow weight gain
2. Acute illness - vomiting/diarrhoea, reduced intake.
3. Co-morbidities - GIT disorder, CF, renal disorder, congenital heart disease, immunocompromised.
4. Medications - diuretics, hyper/hypotonic fluids, nephrotoxic drugs.

Question 2

% Dehydration

Answer 2

% Dehydration = pre-morbid weight - current body weight
* (100g=100ml=1% dehydration)
** Mild = <5%, Moderate = 5-9%, Shock > 10%

Question 3

Moderate (5-9%)

Answer 3

LOC - lethargic, irritable.
HR - mild tachycardia.
RR - incr. RR.
Eyes/fontanel - sunken.
MM - dry.
Turgor - mild decrease.
CRT - delayed.

Question 4

Shock (>10%)

Answer 4

LOC - confusion, drowsiness.
HR - tachycardia.
RR - tachypnoea, acidotic.
BP - hypotension.
Skin - pale/mottled.
Peripheries - cool, weak pulses.
Eyes/fontanel - deeply sunken.
MM - dry.
Turgor - decreased.
CRT - marked delay.

Question 5

Types of fluid therapy

Answer 5

1. Resuscitation - Emergency.
2. Rehydration - Correct deficit.
3. Maintenance - Supplement inadequate intake.
4. Replacement - Replace ongoing losses.

Question 6

Resuscitation

Answer 6

IV Bolus - 10-20ml/kg of 0.9% NaCl
* ASAP and repeat assessment.

Question 7

Deficit

Answer 7

Deficit = (pre-morbid weight - current weight) x 1000; OR
Deficit = weight x % dehydration x 10

Question 8

Rehydration (Enteral)

Answer 8

Indication - preferred route EXCEPT severe dehydration/shock or contraindications.
Contra - NBM/fasting, bowel obst., ALOC, BOSF.
Fluid - ORS (>1 month)
Bolus - age/condition appropriate.
Continuous - V/D, resp. distress.
Slow - 0-6hrs: 5% deficit, 6-24hrs: maintenance volume.
Rapid - 0-4hrs: 10-25ml/kg/hr (NOT - <6months, CNS infection, resp. illness, abdo pain, electrolyte imbalance)

Question 9

Rehydration (IV)

Answer 9

Indication - severe dehydration/shock or enteral contra.
Fluid - 0.9% NaCl + glucose 5% (+/-K+)
< 5% - replace over 6hrs.
> 5% - replace 5% over 24hrs, replace remainder over next 24hrs.

Question 10

Full maintenance

Answer 10

Children not drinking adequately but otherwise not unwell - e.g. maintenance phase of gastro.
4-2-1 rule:
0-10 kg: 4ml/kg/hr
10-20kg: 2ml/kg/hr
20+kg: 1ml/kg/hr
MAX - 100ml/hr or 2400ml/day

Question 11

Fluid restriction.

Answer 11

Most unwell children only require 2/3 of full maintenance dose as they secrete excess ADH which places them at increased risk of fluid overload.

Question 12

Replacement (ongoing losses)

Answer 12

Calculate and replace loss (ml) at 4hr intervals.
E.g. 200ml loss in 4 hrs = 50ml/hr for next 4hrs.

Question 13

IV cannulation - 6 steps

Answer 13

1. Is the IV cannula indicated for the pt?
2. Is the IV cannula working?
3. Look - redness, swelling, blood, displacement?
4. Touch - warmth, pain?
5. Dressing - dry and intact?
6. Document