Dehydration


− Dehydration results from excessive loss of water and electrolytes from the body. If prolonged, dehydration can compromise organ perfusion, resulting in shock. 
− It is principally caused by diarrhoea, vomiting and severe burns.
− Children are particularly susceptible to dehydration due to frequent episodes of gastroenteritis, high surface area to volume ratio and inability to fully communicate, or independently meet their fluid needs.

The protocols below are focused on treatment of dehydration caused by diarrhoea and vomiting. Alternative treatment protocols should be used for children with malnutrition (see Severe acute malnutrition, Chapter 1) or in patients with severe burns (see Burns, Chapter 10).

Clinical features and assessment

− History of diarrhoea and/or vomiting and concomitant reduced urine output.
− Clinical features depend on the degree of dehydration (see table below). Features such as dry mouth, absence of tears may also be noted.
− Patients with severe dehydration should be assessed for shock (tachycardia, low blood pressure and delayed capillary refill time etc.).
− Electrolyte disorders may cause tachypnoea, muscle cramps or weakness, cardiac arrhythmia (irregular heart rate, palpitation), confusion and/or seizures.

Classification of degree of dehydration (adapted from the WHO)1,2



Severe dehydration

At least 2 of the following signs:

Some dehydration

At least 2 of the following signs:

No dehydration

No signs of "severe"
or "some" dehydration.

Mental status

Lethargic or unconscious

Restless or irritable

Normal

Radial pulse

Weak or absent

Palpable

Easily palpable

Eyes(a)

Sunken

Sunken

Normal

Skin pinch(b)

Goes back very slowly
(> 2 seconds)

Goes back slowly
(< 2 seconds)

Goes back quickly
(< 1 second)

Thirst

Drinks poorly or not able to drink

Thirst, drinks quickly

No thirst, drinks normally

(a) Sunken eyes may be a normal feature in some children. Ask the mother if the child's eyes are the same as usual or if they are more sunken than usual.
(b) Skin pinch is assessed by pinching the skin of the abdomen between the thumb and forefinger without twisting. In older people this sign is not reliable as normal aging diminishes skin elasticity.

Treatment of dehydration

Severe dehydration

– Treat shock if present (see Shock, Chapter 1).
– If able to drink, administer oral rehydration solution (ORS) PO whilst obtaining IV access.
– Insert peripheral IV line using large caliber catheter (22-24G in children or 18G in adults) or intraosseous needle.
– Administer Ringer lactate (RL)
1  according to WHO Treatment Plan C, monitoring infusion rate closely:

WHO Treatment Plan C1,2

Age

First, give 30 ml/kg over(a):

Then, give 70 ml/kg over:
Children < 1 year
1 hour5 hours
Children ≥ 1 year and adults30 minutes

½ hours

(a) Repeat once if radial pulse remains weak or absent after first bolus.

– In case of suspected severe anaemia, measure haemoglobin and treat accordingly (see Anaemia, Chapter 1).2
– As soon as the patient is able to drink safely (often within 2 hours), provide ORS as the patient tolerates. ORS contains glucose and electrolytes which prevent development of complications.

– Monitor ongoing losses closely. Assess clinical condition and degree of dehydration at regular intervals to ensure continuation of appropriate treatment.

If over the course of treatment the patient:

• remains or becomes lethargic: measure blood glucose level and/or treat hypoglycaemia (see Hypoglycaemia, Chapter 1).

develops muscle cramps/weakness and abdominal distention: treat for moderate hypokalaemia with 7.5% potassium chloride syrup (1 mmol of K+/ml) PO for 2 days:
Children under 45 kg: 2 mmol/kg (2 ml/kg) daily (according to weight, the daily dose is divided into 2 or 3 doses)
Children 45 kg and over and adults: 30 mmol (30 ml) 3 times daily
This treatment should only be given as an inpatient3 .

develops peri-orbital or peripheral oedema: reduce the infusion rate to a minimum, auscultate the lungs, re-evaluate the stage of dehydration and the necessity of continuing IV rehydration. If IV rehydration is still required, continue the infusion at a slower rate and observe the patient closely. If IV rehydration is no longer required, change to oral treatment with ORS.

develops dyspnoea, cough and bibasal crepitations are heard on auscultation of the lungs: sit the patient up, reduce the infusion rate to a minimum and administer one dose of furosemide IV (1 mg/kg in children; 40 mg in adults). Monitor the patient closely over 30 minutes and assess for underlying cardiorespiratory or renal disease. Once the patient is stabilised, reassess the degree of dehydration and the necessity of continuing IV rehydration. If IV rehydration is still required, re-start at half the previous infusion rate and monitor closely. If IV rehydration is no longer required, change to oral treatment with ORS.

Some dehydration

– Administer ORS according to WHO Treatment Plan B which equates to 75 ml/kg ORS given over 4 hours.

WHO Treatment Plan B1,4

Age

4 months

4 to 11 months

12 to 23 months

2 to 4 years

5 to 14 years

≥ 15 years

Weight

< 5 kg

5 to 7.9 kg

8 to 10.9 kg

11 to 15.9 kg

16 to 29.9 kg

≥ 30 kg

Quantity of ORS over 4 hours

200 to 400 ml

400 to 600 ml

600 to 800 ml

800 to 1200 ml

1200 to 2200 ml

2200 to 4000 ml

– Encourage additional age-appropriate fluid intake, including breastfeeding in young children. Give additional ORS after each loose stool (see below).
– Monitor ongoing losses closely. Assess clinical condition and degree of dehydration at regular intervals to ensure continuation of appropriate treatment.

No dehydration

Prevent dehydration:
– Encourage age-appropriate fluid intake, including breastfeeding in young children.
– Administer ORS according to WHO Treatment Plan A after any loose stool.

WHO Treatment Plan A1,2

AgeQuantity of ORS
Children < 2 years

50 to 100 ml (10 to 20 teaspoons)

Children 2 to 10 years100 to 200 ml (½ to 1 glass)
Children > 10 years and adultsat least 250 ml (at least 1 glass)

Treatment of diarrhoea

In addition to the WHO treatment plan corresponding to patient's degree of dehydration:
– Administer aetiologic treatment if required.
– Administer zinc sulfate to children under 5 years (see Acute diarrhoea, Chapter 3).



Footnotes
Ref Notes
1 If RL not available, 0.9% sodium chloride can be used.
2 If transfusion is required, it should be provided in parallel to IV fluids, using a separate IV line. The blood volume administered should be deducted from the total volume of Plan C.
3 If available, take blood tests to monitor urea and electrolyte levels.
4 For more detailed information on ORS recommendations by age and weight, refer to the guide Management of a cholera epidemic, MSF.


References

  1. World Health Organization. The treatment of diarrhoea : a manual for physicians and other senior health workers, 4th rev. World Health Organization. 2005. 
    https://apps.who.int/iris/handle/10665/43209

  2. World Health Organization. Pocket book of Hospital Care for children. Guidelines for the Management of Common Childhood Illnesses. 2013.
    https://apps.who.int/iris/bitstream/handle/10665/81170/9789241548373_eng.pdf?sequence=1