RT Book, Section A1 Lister, George E. A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 6720356 T1 Chapter 103. Decreased Perfusion and Circulatory Shock T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=6720356 RD 2024/03/28 AB Systemic perfusion can be reduced by a wide variety of processes and diseases that affect the infant and child. If the poor perfusion is not promptly recognized and appropriate intervention taken, there can be rapid progression to circulatory shock, a life-threatening state. While the regulatory mechanisms that control circulatory function are similar at all ages, some developmental features render the infant and young child vulnerable to shock: (1) the infant’s high surface-to-mass ratio causes excessively high insensible water loss when there is fever, hypermetabolism, or a dry environment; (2) the lack of free access to fluids limits the infant’s ability to restore a fluid-volume deficit; (3) the exposure to certain pathogens and susceptibility to overwhelming infection predispose the young infant to septicemia; and (4) the perinatal closure of the ductus arteriosus can precipitate a severely reduced systemic perfusion in the presence of aortic stenosis or coarctation. The clinician who examines the child with poor perfusion must thoroughly, rigorously, and quickly assess the extent of the impairment to determine the most likely mechanism(s) contributing to the circulatory disturbance and to initiate therapy to restore circulation.