Questions and Answers
What is the primary reason why managing fluid and electrolyte balance is critical in pediatric surgical patients?
Why are infants more prone to fluid overload or dehydration?
What type of surgical diagnoses are characterized by a predisposition to fluid loss?
What is the duration of an infant's physiologic day?
Signup and view all the answers
What is a common clinical sign of dehydration in pediatric patients?
Signup and view all the answers
What is the approximate total body water of a fetus at 12 weeks' gestation?
Signup and view all the answers
What happens to total body water within the first week of life?
Signup and view all the answers
What is the approximate total body water of an adult?
Signup and view all the answers
What is the estimated daily fluid requirement for a newborn infant with gastroschisis?
Signup and view all the answers
What is the glomerular filtration rate (GFR) of a term newborn?
Signup and view all the answers
What is the maximum urine concentration that a preterm infant can achieve?
Signup and view all the answers
What is the sodium requirement for critically ill preterm infants?
Signup and view all the answers
What is the fluid requirement for a 26-kg child?
Signup and view all the answers
At what age does the glomerular filtration rate (GFR) reach adult levels?
Signup and view all the answers
What is the limitation in the infant's collecting tubules that leads to insensitivity to antidiuretic hormone (ADH)?
Signup and view all the answers
What is the potassium requirement for infants?
Signup and view all the answers
Study Notes
Fluid and Electrolyte Balance in Pediatric Surgical Patients
- Critical understanding of fluid and electrolyte balance is essential in pediatric surgical patients, particularly in infants, due to their limited reserve and high risk of dehydration or fluid overload.
- Certain surgical diagnoses, such as gastroschisis or short-gut syndrome, are prone to fluid loss, while others, like congenital diaphragmatic hernia, require careful restoration of intravascular volume to prevent cardiac failure.
Infant Physiologic Day and Fluid Balance Assessment
- An infant's physiologic day is approximately eight hours in duration, making regular assessment of fluid balance crucial.
- Assessment should include fluid intake and output for the previous eight hours to prevent dehydration or fluid overload.
Clinical Signs of Dehydration and Fluid Overload
- Clinical signs of dehydration: tachycardia, decreased urine output, reduced skin turgor, depressed fontanelle, absent tears, lethargy, and poor feeding.
- Clinical signs of fluid overload: new oxygen requirement, respiratory distress, tachypnea, and tachycardia.
Physical Assessment of Fluid Status
- A complete head-to-toe evaluation is necessary to determine whether perturbations in normal physiology are present.
Total Body Water and Extracellular Fluid
- At 12 weeks' gestation, the total body water of a fetus is approximately 94 cc/kg, decreasing to around 80 cc/kg at full term.
- Total body water drops an additional 5% within the first week of life, reaching adult levels (60-65 cc/kg) by 1 year of life.
- Extracellular fluid reduces parallel to the drop in total body water, with accelerated changes in preterm infants.
Daily Maintenance Fluid Requirements
- Formula for estimating daily maintenance fluids: 100 mL/kg for the first 10 kg, plus 50 mL/kg for 11-20 kg, plus 25 mL/kg for each additional kilogram of body weight thereafter.
- Conversion to IV fluid orders: 4 mL/kg/h up to 10 kg, add 2 mL/kg/h for 11-20 kg, and add 1 mL/kg/h for each additional kilogram body weight thereafter.
Neonatal Fluid Management
- Newborn infants with gastroschisis may require fluid requirements of 150-180 cc/kg/day due to evaporative losses from the exposed bowel.
- Precise management of a neonate's fluid status requires understanding of changes in glomerular filtration rate (GFR) and tubular function of the kidney.
Glomerular Filtration Rate (GFR) and Tubular Function
- Term newborn's GFR is approximately 21 mL/min/1.73 m2, increasing to 60 mL/min/1.73 m2 within the first 2 weeks of life and reaching adult levels by 2 years of age.
- Capacity to concentrate urine is limited in preterm and term infants, with a maximum concentration of 600 mOsm/kg compared to 1200 mOsm/kg in adults.
Sodium and Potassium Requirements
- Sodium requirements: 2 mEq/kg per day in term infants, up to 5 mEq/kg per day in critically ill preterm infants due to salt wasting.
- Potassium requirements: 1-2 mEq/kg per day.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Understanding fluid and electrolyte balance is crucial in pediatric surgery, especially in infants who have little reserve. Meticulous attention to hydration status is necessary to prevent fluid overload or dehydration.