From the Guidelines
For a 16 kg child requiring IV rehydration, I recommend administering 20 mL/kg of an isotonic crystalloid, such as lactated Ringer’s or normal saline solution, as the initial bolus, which would be 320 mL, over 5-20 minutes for severe dehydration, or over 1 hour for mild to moderate dehydration, as per the guidelines outlined by the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1.
Key Considerations for IV Rehydration
- The choice of fluid for the initial bolus in severe dehydration should be an isotonic crystalloid to rapidly restore intravascular volume.
- For mild to moderate dehydration, oral rehydration solution (ORS) is recommended as the first-line therapy, but if IV rehydration is necessary, the same principles apply.
- The calculation of the bolus volume is based on the child's weight, with 20 mL/kg being a standard dose for the initial bolus in cases of severe dehydration.
- Maintenance fluids should be calculated based on the child's weight, using a formula such as the Holliday-Segar formula, which estimates maintenance fluids as 100 mL/kg for the first 10 kg of body weight, plus 50 mL/kg for the next 10 kg, plus 20 mL/kg for each kilogram over 20 kg.
- For a 16 kg child, using the Holliday-Segar formula, the maintenance fluid rate would be 100 mL/kg for the first 10 kg (1000 mL), plus 50 mL/kg for the next 6 kg (300 mL), totaling 1300 mL/day, or approximately 54 mL/hour.
- The preferred maintenance fluid, once adequate urine output is established, could be D5 0.45% NS with 20 mEq/L KCl, adjusting the rate based on ongoing losses and the child's clinical status.
- Monitoring of vital signs, urine output, and electrolytes is crucial to adjust the IV fluid therapy as needed to prevent both fluid overload and continued dehydration.
Rationale
The approach is based on the most recent and highest quality evidence available, which emphasizes the importance of rapid restoration of intravascular volume in severe dehydration and the use of maintenance fluids that approximate the child's physiologic needs based on weight 1. The guidelines also highlight the role of oral rehydration therapy as the first line for mild to moderate dehydration but support the use of IV isotonic crystalloids when necessary, especially in cases of severe dehydration or when oral therapy is not tolerated.
From the Research
IV Rehydration Dose in a 16 kg Child
- The ideal IV rehydration dose for a 16 kg child is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, study 4 mentions that Normal Saline (NS) and Ringer Lactate (RL) can be used for rehydration in children with acute diarrhea and severe dehydration, following the World Health Organization (WHO) plan C.
- Study 2 discusses the use of maintenance intravenous fluids, including normal saline, dextrose-supplemented saline, and lactated Ringer solution, in children with gastroenteritis and failure of oral rehydration therapy.
- Study 5 provides a general overview of clinical dehydration and its treatment, but does not specify the ideal IV rehydration dose for a child of a particular weight.
- Study 6 provides information on body fluid balance, dehydration, and intravenous fluid therapy, but does not provide specific guidance on the ideal IV rehydration dose for a 16 kg child.
- Study 3 compares the use of hypertonic saline-dextran solution and lactated Ringer's solution for resuscitating severely dehydrated calves, but its relevance to human pediatric care is unclear.
Rehydration Fluids
- Normal Saline (NS) and Ringer Lactate (RL) are commonly used for rehydration in children with acute diarrhea and severe dehydration 4.
- Dextrose-supplemented saline and lactated Ringer solution may also be used for maintenance intravenous fluids in children with gastroenteritis and failure of oral rehydration therapy 2.
- The choice of rehydration fluid may depend on the individual child's clinical and biochemical variables 2.