Table 6.8.
Clinical signs and assessment of extent of dehydration
| I Signs of dehydration | Practical guide: RAHC and QEHC |
|---|---|
| 2–3% dehydration: | Thirst, mild oliguria |
| 5% dehydration: | Discernible alteration in skin tone, slightly sunken eyes, some loss of intraocular tension, thirst, oliguria. Sunken fontanelle in infants |
| 7-8% dehydration: | Very obvious loss of skin tone and tissue turgor, sunken eyes, loss of intraocular tension, marked thirst and oliguria. Often some restlessness or apathy. |
| 10% dehydration (and over): | All the foregoing, plus peripheral vasoconstriction, hypotension, cyanosis, and sometimes hyperpyrexia. Thirst may be lost at this stage. |
| II Assessment of dehydration and fluid deficit (WHO) | |||
|---|---|---|---|
| Signs and symptoms | Mild dehydration | Moderate dehydration | Severe dehydration |
| General appearance and condition | |||
| Infants and young children | Thirsty; alert; restless | Thirsty; restless; or lethargic but irritable when touched | Drowsy; limp; cold; sweaty, cyanotic extremities; may be comatose |
| Older children and adults | Thirsty; alert; restless | Thirsty; alert; giddiness with postural changes | Usually conscious; apprehensive; cold, sweaty cyanotic extremities, wrinkled skin of fingers and toes; muscle cramps. |
| Radial pulse1 | Normal rate and volume | Rapid and weak | Rapid, feeble, sometimes impalpable |
| Respiration | Normal | Deep, may be rapid | Deep and rapid |
| * Anterior fontanelle2 | Normal | Sunken | Very sunken |
| * Systolic blood pressure3 | Normal | Normal-low | Less than 10.7 kPa (80 mm Hg); may be unrecordable |
| *Skin elasticity1 | Pinch retracts immediately | Pinch retracts slowly | Pinch retracts very slowly (> 2 seconds) |
| *Eyes | Normal | Sunken | Deeply sunken |
| Tears | Present | Absent | Absent |
| Mucous membranes5 | Moist | Dry | Very dry |
| *Urine flow6 | Normal | Reduced amount and dark | None passed for several hours; empty bladder |
| Body weight loss (%) | 4–5 | 6–9 | 10% or more |
| Estimated fluid deficit | 40–50 ml kg−1 | 60–90 ml kg−1 | 100–110 ml kg−1 |
4 Not useful in marasinic malnutrition or obesity.
If radial pulse cannot be felt, listen to heart with stethoscope.
Useful in infants until fontanelle closes at 6–18 months of age. After closure there is a slight depression in some children.
Difficult to assess in infants.
Dryness of mouth can be palpated with a clean finger. Mouth may always be dry in a child who habitually breathes by mouth. Mouth may be wet in a dehydrated patient due to vomiting or drinking.
A marasmic baby or one receiving hypotonic fluids may pass good urine volumes in the presence of dehydration.
RAHC = Royal Alexandra Hospital for Children.
QEHC = Queen Elizabeth Hospital for Children.
Particularly useful in infants for assessment of dehydration and monitoring of rehydration.