Hospitals & Services
Children have comparatively higher water content than adults. They dehydrate easily. Stroke volume is relatively fixed, so tachycardia is the main response to poor cardiac output. Hypotension is a late sign if circulatory insufficiency, it is important therefore to note earlier signs such as prolonged capillary return (>2-3 secs). Fluid resuscitation in the ICU is generally given IV as bolus 0.9% saline, 10-20ml/kg in the absence of significant cardiac disease. As circulating blood volume is 80ml/kg, by the time the child has received 2 boluses (total 40ml/kg, ½ circulating volume), consideration should be given to administering blood products.
Full maintenance IV fluid is usually 5% dextrose with 0.45% saline or 0.9% saline. (0.9% saline with dextrose preferred in head injury/neurosurgical patients) "Rule of thumb" maintenance fluid for a WELL child is:
Note that this is recommended for a well child, not a sick child who is ventilated in ICU. Give ~ 2/3 of recommended amount to ventilated children, (sick, ventilated children have increased ADH production, leaving them vulnerable to water retention / fluid overload and hyponatraemia). Consider giving maintenance fluid as NG breast milk/formula/standard enteral nutrition if appropriate. What ever amount of volume is given, accurate 24 hours fluid balance is essential.
Urine output is comparatively higher in small children. A baby should have a urine output 2ml/hr minimum, an older child 1ml/hr minimum. An IDC is not mandatory, but moderate opiate doses (>20mcg/kg/hr) will lead to sphincter dysfunction and urinary retention, so in a child with low urine output, estimation of bladder volume is paramount.
Some children (eg: those with gastro) will need slow rehydration, depending on estimated degree of dehydration /fluid deficit. Information on this can be found in the CDHB paediatric handbook on line.