Dehydration

Maintenance fluid requirements

  • 4cc/kg/hr for 0-10kg (or 100cc/kg/day)
  • 2cc/kg/hr for 11-20kg (or 50cc/kg/day)
  • 1cc/kg/hr for 21+kg (or 25cc/kg/day)

Maintenance electrolyte requirements

  • Na: 2-4mmol/kg/day
  • K: 1-2mmol/kg/day

 

NS

½ NS

RL

D5W

D5 ½ NS

2/3 D5W 1/3 NS

[Na]

154

77

130

0

77

51

[K]

0

0

4

0

0

0

[Glucose] g/100ml

0

0

0

5

5

3.33

* 2/3,1/3 with potassium is a good fluid for maintenance
* D5 ½ NS is a good fluid if dehydrated

History

  • Losses (vomit, diarrhea, bleeding, sweating)
  • Duration, quantity, frequency
  • Amount of intake (oral, IV)
  • Type of replacement
  • Frequency of urination
  • Change in weight, change in activity level


Physical exam

Physical signs

Mild

Moderate

Severe

CVS

HR

Normal

↑↑↑

BP

Normal

Normal – slight ortho drop

Orthostatic drop – ↓

JVP

Normal

↓↓↓

Capillary refill

Normal

2 – 4 seconds

> 4 seconds

Skin

Colour

Normal

Pale

Mottled

Turgor

Normal

1 – 2 seconds

> 2 seconds

Fontanelle

Normal

Slight ↓

Sunken

Mucous membranes

Normal

Dry

Parched

Tears

Normal

Absent

U/O

↓↓

Oliguria/Anuria

Thirst

↑↑

↑↑↑

Weight loss

3 – 5%

6 – 10%

> 10%

CNS

Normal

Irritable

Lethargic

 

  • See table above

Lab tests

  • Lytes, BUN, creatinine, glucose
  • U/A
  • Serum and urine osmolality
  • Urine lytes
  • ABG if severe acidosis

Management

  • Most common in pediatrics is GI losses and poor intake
  • Ideally ORAL rehydration should be attempted (Pedialyte, Lytren – not juice/Gatorade because too much glucose will cause more water loss due to osmosis)
    • Mild: 10cc/kg bolus over 1 hr, then 10cc/kg/hr plus 10cc/kg/stool –> reassess in 4-6 hr
    • Moderate: 20cc/kg bolus over 1 hr, then 20cc/kg/hr plus 10cc/kg/stool –> reassess in 4-6 hr
    • If moderate or severe dehydration, the patient will require IV rehydration
      • Serum Na 130-150; CVS and renal normal
        • Bolus NS 10-20cc/kg over 1 hr
        • Maintenance + Deficit + Ongoing losses (D5 ½ NS + 40mmol KCl/L add KCl only after child has voided)
        • Deficit = H2O (%body weight), Na 4-8mmol/kg, K 2-4mmol/kg
        • Replace ½ deficit over first 8 hr along with maintenance, and the remainder over the next 16 hr

On your OSCE exam write FULL admission orders (DAT (breastfeeding ad lib), AAT, VSR…), also don’t forget to put guidelines for vitals for housestaff to be called, and accurate ins and outs. Date, time and sign your order… also put your pager number.

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