TY - CHAP M1 - Book, Section TI - Polycythemia A1 - Gomella, Tricia Lacy A1 - Cunningham, M. Douglas A1 - Eyal, Fabien G. A1 - Tuttle, Deborah J. PY - 2013 T2 - Neonatology: Management, Procedures, On-Call Problems, Diseases, and Drugs, 7e AB - The hematocrit (Hct) is 68% in a newborn. Polycythemia is defined as a venous hematocrit above 65% or a hemoglobin >22 g/dL. Polycythemia occurs in 2–4% of newborns and is rare in premature infants 14 centipoise (shear rate of 11.5 seconds) and is also defined as 2 standard deviations greater than the norm. Polycythemia hyperviscosity syndrome (PHS) is the symptom complex that involves polycythemia, hyperviscosity, and the symptoms that accompany it. Forty seven percent of polycythemic infants have hyperviscosity. Twenty-four percent of infants with hyperviscosity have polycythemia. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1107527960 ER -