week 5- peadiatric physiology Flashcards
what are the anatomical differences in chuldren, infants and adutls of the airway?
larger head to body ratio
small mandable and neck
large posteriorly placed tounge
high c=glottic positioning
different shaped epiglotis- floppier and horsehoe shape
larynx situated more anteriorly angle at vocal chords
trachea softer and more cartlinogous
what are the differences in peadiatric ear nose and throats?
infants under 6 months are nasal breathers - nasal secretions can easily objstruct airflow
external ear cannal faltter and wider- more likley to get infectionwh
what are different in the respiritory system
nenonates- pulmonary surfactsnt produced at 24 weeks- sufficent amount at 35 weeks
premature infants prone to respiroty distress syndrome
Infants0 lungs are realativly imature at birth
small total surface area at b irth
oxygen consumtion is 6ml/kg/min which is double an adults
what are the rspiritoy differences in infants?
Infants0 lungs are realativly imature at birth
small total surface area at b irth
oxygen consumtion is 6ml/kg/min which is double an adults
what are the resp differences in chlidren?
resp system grows and matures until 8 years of age
predominantly diaphragmatic breathers until 6-8
chest wall more cartlaginous and flexiable- reduced compliances
intercostal muscles soft
ribs more horizontal- limiting volume of expantion
muscles are quicker to fatigue
why do peadiatric patients have a higher respirorty rate?
greater metabolic rate and higher o2 consumtion
tidal volume of 5-7ml/kg
higher minute volume
realtivly few type 1 fatigue resistant fibers- tire easliy if work of breathing is increased
WOB uses 25% of O2 consumption
why are peadiatric patiens at higher risk of respiritory failre?
decreased respiritory reserve and increased O2 deman
what are the differences of the pead circulatory system?
realtive cirulating blood volume is higher than adults- 70-80ml/kg but overall volume is low
SV is small and relativly fixed- CO dependant on HR
TPR rises after birth- reduces ability to compensate with increased CO to maintain BP
what is the difference in a pead vascular system?
more dynamic- peripheries constrict to divert blood flow to cental circulation
what is the difference in a pead immune system
immature at birth
maternal antibodies provide limited protection that declines after 6 months
what are the differences in peads skin?
larger. ody surface area to greater risk of heat and fluid loss
thinner and less keratin
more quickly affected by topical toxins
what are the differnce in peadiatric GIT?
relaxed gastric sphincter can lead to reflux and regurgitaitopn
gastric secretions neutral at birth and reach adult change at 3 years
stomach time emptying increased
quick transet through small intestines and large bowel reduces absorbtion of nutrients
large liver
what are the musculoskeletal changes in peads?
Immatrure bone is more flexable
presence of growth plates (physis)- allow for growth of bones untill end of pubity- susceptable to injury
limited ossification of the boens
not complete until 20 years old
bone of vertabre, sternum and clavical not complete until 23-25 years old
what are the differences of pead pharmacokinetics?
absorbtion
Limited high quality studies
GOT transit variable
altered fat absorption and active absorption alters drug bioavaliability
muscle perfusion highly variable in neonate and IM routes unrelaible
what are the differences of pead pharmacokinetics?
Distribution
higher % body water in younger children- greater distibution of hydrophilic drugs
Higher % body fat leads to greater distribution of lipophilic drugs
Blood brain barrier realtivly underdeveloped- allows more drugs to achive higher concertrations than normal in younger children
