Ex. 6 - Intro to Pediatrics (69) Flashcards
Pediatric patient populations
Approx. 22% of people living in the US are <18 years
Community: around 14% of children take at least one chronic medication (3 months+)
Hospital: 5.2 mill pediatric hospitalizations in 2019
-Includes new births (3.6 million)
-Outside newborns, about half of patients go through emergency department
-Children under 10 -> respiratory diagnoses
-Children 10 and older -> mental health diagnoses
Children are/are not small adults
ARE NOT
Fontanelle + open sutures
Short narrow trachea
Rate dependent cardiac output
Reduced ability to concentrate urine
Larger BSA: weight ratio
-Head size
-Higher metabolic rate and caloric needs
-Smaller lung volume
Higher percentage of body water
Soft bones
Pediatric Terminology
Pediatric: birth to 18 years
Neonate: 0-28 days of life
-Pre term: <37 completed weeks gestational age
-Term: 37 weeks gestational age or greater (usually 40 weeks)
Infant: 28 days/1 month up to 12 months
Child: 1-11 years
Adolescent: 12-18 years “late adolescent” sometimes used for 18-21)
Neonatal Terminology
First day of last menstrual period
-Gestational age
Postmenstrual age
-Postnatal age (chronological age)
Corrected age = Postnatal (actual) age - weeks (or months) born early
Ex: a now 16 week old baby born at 28 weeks gestational age
-40 expected gestation - 28 weeks actual gestation = 12 weeks premature
Corrected age
-16 weeks (actual) - 12 weeks (#early) = 4 weeks corrected age
Q: A woman approaches your pharm with her baby. She tells you the baby is 8 weeks old and was born early at 31 weeks. What is the patient’s post menstrual age?
postmenstrual: 39 weeks
Pediatric growth
Pediatric patients should grow
Infant weight doubles by 4-6 months
Infant weight triples by 12 months
Length increases 50% by 12 months
Check and document wright/height at every well-child visit
-Track weight gain to ensure appropriate medication doses (patients may “grow out” of doses)
Growth charts
Tools for monitoring weight, length, and head circumference
-Helpful in assessing nutritional status
-Different versions for girls, boys, and some special populations
-WHO charts for birth-24 months and CDC charts for 2-20 years
Based on averages; may not be appropriate for all patients
To use:
-Plot weight and or length with corresponding age
-Line closest to plotted point = percentile
Q: Use your growth chart to plot the following child: A 5-year old boy weighing 44 pounds who is 110 cm tall
What percentile is his weight for age? His length for age?
Pediatric Vital Signs
Look at chart
Temperature
“Normal” temp 36.5-37.5C
> 100.4F generally considered a fever (38C) but definition varies
Reference range differs by method of measurement and age
Rectal and oral more accurate
Neonates have difficulty regulating temp; more susceptible to environmental factors
When to refer for fever?
Everyone <3 months of age
Fever > 24 hrs if less than 2 years of age
Fever >72 hours if > 2 years of age
Fever > 104F (40C) any age
Everyone if no improvement despite treatment
Clinical picture
-Neck stiffness
-(Sign of menningitis)
-Irritability
-Lethargy
-Vomiting/diarrhea
-Unexplained rash
-Immunocompromised
-Severe pain - HA, earache, sore throat
-Seizure
-“looks sick”
OTC options for fever and pain
Acetaminophen
-10-15mg/kg/dose Q4-6H
-Max dose: 75mg/kg/day OR 4g/day, whichever is lower
-Standard concentration: 160mg/5mL (32mg/mL)
Ibuprofen
-5-10mg/kg/dose Q6-8H
-Give only to children >6 months of age
Max dose: 40mg/kg/day
-Standard concentration: 100mg/5mL (20mg/mL)
-Can causse nephrotoxicity, bleeding
Check concentration before providing doses in mL
Lab values
Some reference ranges similar to adults, others vary
Ex: SCr will be lower (even down to <0.2) in infants
-Byproduct of muscle and infants don’t have much!
-Consult resources for guidance on specific labs
PK
ADME
Absorption
Examples of differences include:
-Thinner skin layers in neonates
-Maturing intestinal motility and generally slower rate of enteral absorption
-Increased gastric pH
oral admin of acid-labile compounds (ex. penicillin G)
-Greater bioavailability
Oral admin of weak acids (Ex. phenobarbital)
-Require relatively larger oral doses
Distribution
-Increased total body water
-Increased extracellular fluid
-Decreased protein binding
Age: Premature neonate
Total body water: 75%
Total body fat: 1%
Age: Term neonate: 75%
Total body water: 75%
Total body fat: 15%
Age: Older children/adults
Total body water: 60%
Total body fat: 20-25%
Metabolism
Liver enzymes take time to mature; dosing requirements can change over time
Ex: CYP1A2 reaches adult levels around 9-12 months of age
Age:
Neonates and infants:
Caffeine Half-life (CYP1A2): 72-96 hrs
Children and Adults:
Caffeine Half-Life (CYP1A2): 3.5-5 hours
Excretion - Assessing renal function
Urine output
-Appropriate = >1 mL/kg/hour
Oliguria = < 0,5mL/kg/hour
Anuria = 0mL/kg/hour
^^KNOW FOR EXAM
Serum creatinine and BUN
Calculate creatinine clearance via Bedside Schwartz
**eGFR (mL/min/1.73m2) = 0.4113 * (height in cm/SCr)
Q: Calculate: Urine Output
Consider if appropriate, oliguria, or anuria
-5kg infant with 300 mL urine output in 24 hours = 2.5mL/kg/hour
Appropriate
12 kg child with 200mL urine output in 24 hours = 0.7 mL/kg/hour
-Olguria
9kg child with 0mL urine output in 24 hours = 0 ml/kg/hour
Anuria
Q: Calculate: Creatinine Cl
13-month-old infant who is 82 cm long with SCr of 0.26mg/dL
130mL/min/1.73m2
16-year old adolescent who is 169 Cm tall with SCr of 2.01mg/dL
35mL/min/1.73m2
10-year-old child who is 136 cm tall with SCr of 0.52mg/dL
108mL/min/1.73m2
Drug References
Best for dosing: Lexi-Comp Pediatric & Neonatal Product (book, app, or website)
General Pediatrics
-Nelson Textbooks of Pediatrics
-Pediatrics in Review - online journal
-NeoReviews - online journal
-Neofax
-Harriet lane handbook
-Pediatric Pharmacotherapy (Purple Book)
Infectious Diseases
-Johns Hopkins ABX guide
-AAP Red Book
Compatibility
-Pediatric Injectable Drugs (Teddy Bear Book)
-Handbook on Injectable Drugs (Trissel’s, via Micromedex)
General Dosing
-Micromedex
-Drug Facts and Comparisons
Pregnancy and Lactation
-Drugs in Pregnancy and Lactation (Briggs)
-LactMed (free app)
Pediatric and Neonatal Dosage Handbook
“Gold Standard” for pediatric dosing information
Updated and maintained by former clinical pharmacists with varied specialties
Pediatric and Neonatal Lexi-Drugs
-Pay attention to headers - signal whether dosing recommendations are for neonates, infants, children, or adults
-Different doses are recommended based on indication
-Reading is required to correctly interpret
-Some fields visible in adult monograph, some are peds only (ex; neonatal dosing, reference range, monitoring)
Dosing
At times, little information
-Often must rely on primary literature and discussions with medical team
Weight risk/benefit
-Withhold treatment due to lack of info
-Provide treatment in face of little info
Never assume prescriber has complete pediatric knowledge base
-When a dose doesn’t “look right,” ask
Dosing Calculations
General rule: do NOT exceed adult dosing
Be mindful of units:
-mg/kg/dose vs mg/kg/day
mg/m2/ dose vs mg/m2/day
-Body surface area (Mosteller)
-BSA (m2) = square root (height [cm] * weight [kg] /3600)
-Sometimes doses are described as total daily dose DIVIDED - make sure you understand what your resource is telling you!
-If the number does not make sense, re-calculate/ask for help
