What Clinical Symptoms Can An Infant with Polycythemia Have?
Discussion
Polycythemia is defined as a venous hematocrit of > 65% or a venous hemoglobin of > 22 g/dL. Capillary values are unreliable and any values greater than normal should be repeated with a venous sampling for confirmation. Hyperviscosity is distinct from polycythemia and “… is defined as a viscosity greater than 14.6 cP at a shear rate of 11.5 per second, or a value 2 standard deviations above the mean.” Hyperviscosity is difficult to measure in the clinical setting therefore polycythemia is often used as a proxy.
Polycythemia occurs in about ~1.5-5% of births. Risk factors for it includes infants that are small for gestation age (SGA, A review is here) and large for gestation age (LGA, A review is here ), infants of diabetic mothers (IDM, a review is here), monochorionic twins (larger twin is more at risk, A review is here), and infants with growth retardation features. Infants born at high altitudes can have polycythemia (a review is here). Polycythemia is less likely in infants < 34 weeks gestation. Other potential risks for polycythemia include acute and chronic hypoxia (e.g. placental insufficiency, preeclampsia, maternal smoking, neonatal thyrotoxicosis), intrauterine transfusion (e.g. materno-fetal, feto-feto) and genetic syndromes such as trisomy 13, 18 and 21 and Beckwith-Weidemann syndrome.
After birth, fluid moves out of the intravascular space and causes the hematocrit to peak at ~ 2 hours of age and decreases around 6 hours o...
Source: PediatricEducation.org - Category: Pediatrics Authors: pediatriceducationmin Tags: Uncategorized Source Type: news
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