Pediatric emergency medicine trisk 1388 1388
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (73.82 KB, 1 trang )
Difference
Consequence
Nose: infants <4 mo
preferential nose breathers
Larynx: higher (C2–C3 vs.
C6), softer, more elastic
Nasal congestion may result in significant
respiratory distress
More difficult to intubate
Collapses more easily, particularly with fixed
obstruction (i.e., Bernoulli principle—as the
velocity of flow through a collapsible tube
increases, the pressure that holds the tube
open decreases)
Trachea: one-third diameter of Poiseuille law—resistance varies inversely
adult at birth, shorter
with fourth power of the radius; 1-mm
thickening decreases cross-sectional
diameter by 20% in adult and by 80% in
child
More difficult to intubate/maintain proper
depth
Alveoli: elastic fibers less well Alveoli collapse more easily, results in
developed
ventilation–perfusion mismatch
Lungs: lower functional
Reserve small, therefore limited protection
residual capacity
when ventilation is interrupted, PaO2
decreases more rapidly
Respiratory control apparatus: Apnea or inability to respond appropriately to
immature—reflexes that
mechanical respiratory obstruction or
inhibit respiration are very
increased metabolic demand
strong; central nervous
system processing of
information markedly
affected by sleep state, cold,
drugs, other metabolic
derangements
Chest wall: more compliant;
Accessory muscle retractions
intercostal muscles
Diaphragm does more work but is less
immature; ribs more
effective
horizontal; diaphragm
