RT Book, Section
A1 Lakshminrusimha, Satyan
A1 Steinhorn, Robin H.
A2 Kline, Mark W.
SR Print(0)
ID 1182919996
T1 Approach to the Cyanotic Infant
T2 Rudolph's Pediatrics, 23e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259588594
LK accesspediatrics.mhmedical.com/content.aspx?aid=1182919996
RD 2024/04/23
AB Cyanosis,  or  bluish  discoloration  of  the  skin,  is  derived  from  the  Greek  word  kuaneos,  meaning  “dark  blue.”  Cyanosis  is  caused  by  the  presence  of  deoxygenated  hemoglobin  in  the  blood  vessels  that  is  most  visible  on  the  surface  of  the  skin  and  mucosa.  The  mechanisms  of  cyanosis  are  outlined  in  Table  51-1  and  Figure  51-1.  In  general,  cyanosis  occurs  because  (1)  the  binding  of  oxygen  to  hemoglobin  is  abnormal,  so  that  blood  does  not  carry  much  oxygen  despite  having  a  normal  partial  pressure  of  oxygen,  or  PO2  (eg,  methemoglobin  or  carboxyhemoglobin);  (2)  the  perfusion  of  the  skin  is  poor,  such  that  the  venous  and  capillary  blood  are  very  deoxygenated  even  though  the  arterial  blood  may  be  well  oxygenated  (eg,  cold  environment  or  circulatory  shock);  or  (3)  the  arterial,  and  therefore  the  capillary  and  venous  blood,  is  poorly  oxygenated  (eg,  a  right-to-left  shunt  with  congenital  cardiac  disease,  parenchymal  pulmonary  disease,  or  hypoventilation).