Pediatrics Flashcards
Definitions of neonate, infant, and child
Neonate: Birth to 30 days
Infant: 1 month to 1 year
Child: 1 - 12 years
Kids develop similar physiology to an adult by age
8 years
Premature is considered
37
Fetal transition to neonatal physiology takes place during the first ___-___ hours
24-72
Ductus arteriosus closure
Anatomic closure: 2-6 weeks
High O2 can help it close
Foramen ovale closure
Functionally: rapid closure
Anatomically: 3 months
CV differences in kids
Noncompliant LV
- limited ability to handle increase in fluid volume
- Unable to increase SV, only able to increase CO by increasing HR (this means that BP depends on HR as well)
Limited catecholamine stores
- May give atropine prophylactically
- Effect of ephedrine?
Fetal circulation considerations
- Cold, hypoxia, and hypercarbia can re-open these shunts
Higher metabolic O2 demand than adults (because they are growing so rapidly!)
Pulmonary differences in kids
Increased O2 consumption
TV and dead space same as adults (dependent on rate for adequate MV for needed O2 demand)
Resp rate is 2-3x that of adults
Increased chest wall compliance
Decreased lung compliance**
SMALL DIAMETER AIRWAYS (increased resistance to flow)
Hypoxia and hypercapnea will depress ventilation (compounds the problem!)
Decreased Type 1 muscle fibers in diaphram (kid poops out quickly from high RR and poor lung compliance)
Fewer alveoli
Smaller FRC**
Unique airway differences in kids
Narrow nasal passages (lean towards using oral airway)
Obligate nasal breathing** (until about 6 months, until then, make sure their nose is clear so they can breath!!!)
Cricoid cartilage is most narrow portion of airway
Short neck, large head, large tongue
Larynx is more cephalad (C4) and is funnel shaped
Epiglottis is narrow and stubby
VC attachment is angled anterior and caudad
Smaller margin of error for R mainstem intubation
How should infants be positioned for intubation?
Towel roll under shoulders b/c their heads are fucking huge. This should align things properly
Also, neck should be neutral or slightly flexed.
Extreme flexion or extension will kink airway***
Just 1mm of airway edema can decrease cross-sectional area by ___%
75%
Fluid/Electrolyte differences in kids
Higher total body water
ECF = 40% of TBW in neonates and 20% of TBW in those over 2 years
More ECF = more prone to dehydration
Kidney function reaches normal by __ months
6 months
Until this time, every week counts for kidney development!!
Hemoglobin levels in kids
Hgb at birth = 18-20g/dL - Most of this here is fetal Hgb and has a shift to the left! This helps to extract O2 from the mother. Low Hgb levels bad in newborn d/t shift to the left. Hgb pre-term = 13-15 g/dL Hgb at 2 months = 10-12 g/dL - Lower threshold for transfusion Hgb at 6-24 months = 12 g/dL Hgb at 2-6 years = 12.5 g/dL Hgb at 6-12 years = 13.5 g/dL
In newborn blood loss >10-15% may not be tolerated Fetal Hgb
Most kids though end up doing ok with low hgb. Always check with surgeon before giving blood to a kid.
Hepatic and GI differences in kids
Low hepatic blood flow in first months of life
CYP450 maturity has huge variability
Type 1 reactions mature faster than Type 2 (conjugation) –> so avoid drugs that undergo type 2
Low glycogen stores (worry about hypoglycemia!)
Impaired conjugation –> jaundice
Poor coordination with breathing and swallowing until 4-5 months (reflux is common!)
Low plasma albumin levels
Kids can’t shiver until __ months
3
Until then, they rely on brown fat metabolism
Keeping kids warm is a huge priority**
Thermoregulation
Brown fat metabolism = high O2 consumption
Thin skin
Low fat content
Large surface area
Interventions: Warmed mattress, blankets, warm room, cover the head, humidify inspired gases, bair hugger
General rules about kids and E1/2t of drugs
Infants: Prolonged E1/2t
Children 2-12: Shortened E1/2t
Reaching adulthood: Normal E1/2t
Highes to lowest MAC requirements
Infant (highest)
Neonate
Child
Adult (lowest)
Preemies tolerate IAs poorly. Use minimally or not at all.