Polycythemic Newborns Research Articles

Evaluation of Neonatal Polycythemia in Terms of Gestational Age, Hematocrit, and Platelet Levels

Objective: The main concern in neonatal polycythemia is complication development due to hyperviscosity. We aimed to compare symptoms, clinical and laboratory features, and organ dysfunctions of polycythemic newborns with respect to gestational age, hematocrit (hct) levels and presence of thrombocytopenia. Material and Methods: Between January 2013 and December 2016, all hospitalized newborns with a gestational age of ≥ 34 weeks were retrospectively evaluated and those with a venous hct value exceeding 65% were included. Exclusion criteria were infections, metabolic diseases and congenital anomalies. Newborns were grouped and compared according to hct values (65–69.9% vs. ≥70%), gestational age (late preterm vs. term) and thrombocytopenia (present/ absent). Results: Polycythemia incidence was 7.7% in the study group. The most common symptoms were hypoglycemia and hyperbilirubinemia, while 35.1% of newborns were asymptomatic. Hypoglycemia, hypocalcemia, and plethora were significantly more frequent in the severe polycythemia (hct ≥70%) group than in the moderate polycythemia (hct between 65–69.9%) group (p = 0.027, p = 0.014, p < 0.001, respectively). Hyperbilirubinemia was more common in late preterm babies than term babies (p = 0.014). Feeding difficulty, convulsion, hypoglycemia, hypocalcemia and liver function test abnormalities were significantly more common in newborns with thrombocytopenia than those without (p = 0.002, p = 0.004, p < 0.001, p = 0.022, p = 0.043, respectively). Conclusion: It should be kept in mind that more than one-third of polycythemic newborns may be asymptomatic. While the most common symptoms were hypoglycemia and hyperbilirubinemia, liver function tests may also be adversely affected.

Serum Endocan, Neuron-Specific Enolase and Ischemia-Modified Albumin Levels in Newborns with Partial Blood Exchange Transfusion.

Hyperviscosity of blood secondary to polycythemia results in increased resistance to blood flow and decrease in delivery of oxygen. To evaluate whether serum endocan, NSE and IMA levels can be compared in terms of endothelial injury/ dysfunction and neuronal damage in term neonates with polycythemia who underwent PET. 38 symptomatic polycythemic newborns having PET and 38 healthy newborns were included in the study. Blood samples for endocan, NSE and IMA were taken at only postnatal 24 hours of age in the control group and in polycytemia group just before PET, at 24 and 72 hours after PET. The polycythemia group had higher serum endocan(1073,4 ± 644,8 vs. 378,8 ± 95,9ng/ml; p<0.05), IMA(1,32 ± 0,34 vs.0,601 ± 0,095absorbance unit; p<0.05) and NSE(44,7 ± 4,3 vs. 26,91 ± 7,12μg/l; p<0.05) levels than control group before the PET procedure. At 24 hours after PET, IMA(0,656 ± 0,07 vs. 0,601 ± 0,095absorbance unit; p<0.05) and endocan(510,9 ± 228,6 vs. 378,8 ± 95,9ng/ml; p<0.05) levels were closer to the control group, being still statistically significant higher. NSE levels decreased to control group levels having no difference between the PET and control groups at 24 hours after PET (28,98 ± 6,5 vs. 26,91 ± 7,12μg/l; p>0.05). At 72 hours after PET the polycythemia and control groups did not differ statistically for IMA, endocan and NSE levels (p>0.05). Serum endocan and IMA levels can be used as a biomarker for endothelial damage/ dysfunction and tissue hypoxia in infants with symptomatic polycytemia.

Partial exchange transfusion results in increased cerebral oxygenation and faster peripheral microcirculation in newborns with polycythemia

The aim of this study was to assess cerebral and peripheral oxygenation, by using near infrared spectroscopy (NIRS) and microcirculation by using side stream dark field (SDF) imaging in newborns with polycythemia before and after partial exchange transfusion (PET) therapy to investigate treatment effect on tissue oxygenation and microcirculation. Polycythemic newborns with venous haematocrit (Htc) >70% or ≥65% with symptoms were included. NIRS measurements for cerebral and peripheral oxygenation and SDF recordings for microcirculatory flow assessment were obtained before and after PET. Fractional tissue oxygen extraction (FTOE) was calculated based on tissue oxygenation index and oxygen saturation. Wilcoxon test was used for statistical analysis. Fifteen newborns were included. Cerebral tissue oxygenation index, microvascular flow index and % of vessels with hyperdynamic flow increased after PET; median (range): 61.27 (51.36-61.87) versus 64.54 (54.1-74.38), 2.74 (2.46-3) versus 3.22 (2.64-3.75) and 0 (0-2.8) versus 3 (0-99.3), respectively. Whereas cerebral fractional tissue oxygen extraction (CFTOE), % of vessels with sluggish flow decreased after treatment; 0.36 (0.22-0.44) versus 0.31 (0.17-0.46), 1.4 (0-69) versus 0 (0-0.9), respectively. Peripheral oxygenation was unchanged. Partial exchange transfusion improves microcirculation in polycythemic newborns. Cerebral oxygenation increases and cFTOE decreases suggesting increased blood flow. Microvascular flow increases possibly representing reactive hyperperfusion after hemodilution. Whether these effects are beneficial require further research.

The evaluation of polycythemic newborns: efficacy of partial exchange transfusion

Objectives. To evaluate the clinical characteristics and risk factors of symptomatic and asymptomatic polycythemic neonates performed partial exchange transfusion (PET) and to determine the time of resolution of symptoms and effect of PET on short-term morbidity.Methods. This prospective cohort study was conducted with symptomatic (hematocrit; Hct >65% plus a clinical symptom) and asymptomatic (Hct level >70% without any symptoms) neonates who underwent PET due to polycythemia.Results. Among the patients performed PET, 43 (69.3%) were symptomatic and 19 (30.7%) asymptomatic. Persistent pulmonary hypertension and minor problems like hypoglycemia, hypocalcemia, hyperbilirubinemia, and thrombocytopenia improved in all patients within 24 h, 2.5 ± 1.0, 3.1 ± 1.4, 56.2 ± 16.9, and 53.5 ± 10.5 h, respectively, after PET (in except one symptomatic neonate with hypoglycemia). In symptomatic group, in three patients with suspected necrotizing enterocolitis (NEC) prior to PET stage IIa NEC developed. No other clinical and ultrasonographic findings were observed after PET.Conclusions. Early morbidities, due to polycythemia may be reversed with PET within a short time. PET did not increase or cause any complications except NEC. The issue that either NEC was a sign of polycythemia or a complication of PET could not be definitely outlined.

Use of crystalloid or colloid for partial exchange transfusion in polycythemic newborns

Use of crystalloid or colloid for partial exchange transfusion in polycythemic newborns

Properties of thyroid-stimulating hormone and cortisol secretion by the human newborn on the day of birth.

Secretory activation of the thyroid and adrenal glands is a hallmark of the neonatal adaptation to extrauterine life. TSH and cortisol play key roles in these axes. The highest serum concentrations of TSH attained over the full span of human life are normally found shortly after birth. Serum cortisol is also known to be elevated in the immediate postnatal period. However, the dynamics of TSH and cortisol secretion have hitherto not been documented on the day of birth. To study the properties of neonatal TSH and cortisol secretion, we obtained arterial blood at regular intervals (every 20 min for 6 h) from nine polycythemic newborns (gestational age, 34-41 weeks) on the first and/or fourth days after birth during a therapeutic, standardized, isovolumetric, partial exchange transfusion. One premature infant had received betamethasone antenatally. The serum TSH level of an infant with congenital hyperthyroidism of transplacental origin was also measured at the postnatal age of 1 h. Deconvolution analysis of the profiles revealed that all infants displayed a combination of basal and pulsatile TSH release. Bursts of TSH secretion occurred at a median interval of 133 min. The median serum TSH half-life was 75 min. On the day of birth, basal TSH secretion and the amplitude of pulsatile TSH secretion were higher than 3 days later. Cortisol was secreted exclusively in a pulsatile fashion. Bursts of cortisol release occurred at a median interval of 69 min. The median serum cortisol half-life was 60 min. Cortisol secretion appeared to shift gradually from a high frequency, low amplitude pattern early on the first day toward a lower frequency, higher amplitude pattern 3 days later. TSH and cortisol secretion were low in the infant who received betamethasone prenatally. Serum TSH was undetectable in the infant with congenital hyperthyroidism. In conclusion, serum TSH concentrations in the human newborn appear to be elevated on the day of birth as a result of amplified basal and pulsatile TSH release, then fall rapidly through a mechanism that decreases the amplitude of TSH secretion and are affected by modulation of the fetal thyroid axis. From the day of birth onward, cortisol was found to be released in an exclusively pulsatile mode, with characteristics that appear to depend on postnatal age and prenatal glucocorticoid exposure.

Properties of growth hormone and prolactin hypersecretion by the human infant on the day of birth.

The neonatal period is the only interval in postnatal life characterized by physiologically elevated plasma concentrations of GH and PRL, two hormones of common origin. To study the secretion of GH and PRL on the day of birth, we obtained at regular intervals (every 20 min for 6 h) blood from seven polycythemic newborns (gestational age 34-41 weeks; birthweight 1600-3960 g; postnatal age 6-23 h) during a therapeutic, standardized, isovolumetric, partial exchange transfusion. Serum GH concentrations were measured by RIA and PRL levels by immunoradiometric assay. Deconvolution analysis of the profiles revealed that all infants displayed a pulsatile pattern of amplified GH release (range 9-191 micrograms/L). Bursts of GH secretion occurred at a median interval of 73 min. The median serum GH half-life was 18 min. All infants had continuously elevated serum PRL concentrations (range 86-191 micrograms/L) and none appeared to release PRL episodically. There was no significant cross-correlation between the secretion of GH and PRL. Mean serum GH concentrations during the 6-h study were higher than in cord serum at birth, whereas PRL and insulin-like growth factor-1 levels were lower than at birth. In conclusion, the neonatal hypersomatotropism appears to be characterized by high-amplitude, high-frequency, pulsatile secretion of GH without a prolonged GH half-life, whereas hyperprolactinemia seems to result from GH-independent, continuous PRL release. The immediate postnatal rise of GH secretion in the human newborn may be related to decreased inhibition by circulating insulin-like growth factor-1.

Elevated calcitonin gene-related peptide in polycythemic newborn infants.

In this study, calcitonin gene-related peptide levels were measured in cord and at 16-36 h of extrauterine life in 43 polycythemic newborns; 20 healthy term infants were also studied as controls. Calcitonin gene-related peptide values were significantly higher in polycythemic neonates in comparison with controls both at delivery and at 16-36 h after birth. Five polycythemic (11.6%) infants who develop hypocalcemia had greater elevated calcitonin gene-related peptide concentrations. Our data suggest that calcitonin gene-related peptide may be implicated in the circulatory adaptation to extrauterine life. In polycythemic neonates, calcitonin gene-related peptide is probably increased to compensate for blood hyperviscosity; in some cases, high calcitonin gene-related peptide concentrations may induce hypocalcemia.

The effect of polycythemia and hypoxia on urinary N-acetyl- β-D-glucosaminidase activity in newborns

Urinary N-acetyl- β-D-glucosaminidase activity was assayed in fullterm and preterm polycythemic neonates, in preterm infants with hypoxia, and in healthy newborns. There were no significant differences between fullterm and preterm babies or between appropriate for gestational age and small for gestational age neonates in the normal group. N-acetyl- β-D-glucosaminidase excretion on the first day of life was significantly raised in polycythemic newborns ( P < 0.01). Fourteen days after partial plasma exchange the enzyme activity returned to normal. N-acetyl- β-D-glucosaminidase activities in preterm babies with respiratory distress syndrome were significantly ( P < 0.01) raised on the 1st, 2nd, 4th days and fell sharply to the 14th day. N-acetyl- β-D-glucosaminidase isoenzyme studies revealed that urine samples taken from preterm babies with respiratory distress syndrome in the first week after birth contained increased amounts of intermediate and B isoenzyme forms while there was a concomitant reduction in the amount of the A form present.

156 EFFECTS OF PARTIAL PLASMA EXCHANGE TRANSFUSION (PPET) ON PERIPHERAL AND CEREBRAL BLOOD FLOW VELOCITY IN POLYCYTHEMIC NEWBORN INFANTS

Cerebral blood flow velocity (CBFV) is decreased in polycythemic newborns and it normalizes after PPET. To study the influence of polycythemia on peripheral blood flow velocity (PBFV) we measured PBFV and CBFV in 17 polycythemic newborns. Nine normocythemic infants served as controls. Blood flow velocity was measured prior to and at 3 and 24 hrs after PPET in the study group and at 3 and 24 hrs after birth in the controls. Flow velocities were recorded with a 5MHz bidirectional continuous wave velocimeter. Hct decreased from 72.5±4.0% to 59.0±1.5% after PPET. Peripheral mean flow velocity (AUC°) in polycythemic newborns did not differ from controls. Cerebral mean flow velocity was decreased in polycythemic newborns and normalized after PPET. NS = Not Significant * P<0.05 ° AUC = Area Under the Curve Values at 24 hrs did not differ from values at 3 hrs. These data show that blood flow velocity is regulated by different mechanisms in different vascular systems.

Plasma protein C and antithrombin III levels in polycythemic newborns.

Thromboembolic complications have been reported in association with neonatal polycythemia, the primary cause of hyperviscosity in the newborn. Although there are some studies on coagulation in polycythemic neonates, the situations that predispose these newborns to thrombosis are still not clear.1 One of the causes may be the reduction in blood flow within the microcirculation, which favors coagulation. As protein C (PC) and antithrombin III (AT III) are important coagulation inhibitors, we decided to study them in polycythemic newborns.

16 EFFECTS OF PARTIAL PLASMA EXCHANGE TRANSFUSION (PPBT) ON CEREBRAL BLOOD FlOW VELOCITY (CBFV) IN POLYCYTHAEMIC NEWBORN INFANTS

In 37 newborn infants with polycythaemia (with or without clinical symptoms) we performed a PPET. CBFV was measured before, 3, 12 and 24 hours after PPET. In a matched control group (N=15) CBFV was measured 6, 12, and 24 hours after birth. CBFV was recorded with a bidirectional 5 mHz continuous wave velocimeter. Recordings were made from the anterior cerebral and left mid cerebral arteries. The study group included 14 term infants, 11 preterm infants and 12 small for date infants. The peripheral venous Hct decreased from 72.5±2.7% X + SD) to 60.1 ± 4.2% after PPET. Heart rate and blood pressure did not change significantly. Peak systolic flow velocity (PSFV), peak diastolic flow velocity (PDFV) and mean flow (AUTC) increased significantly (P < 0.001) at 3 hours after PPET. The PI (PSFV-PDFV/PSFV) did not change significantly (0.1 < P < 0.5). CBFV obtained after PPET did not differ from CBFV in the control group and this remained constant at 12 and 24 hours thereafter. When analysing the changes in CBFV after PPET we observed conparable changes of flow parameters in the 3 subgroups of infants within the study group. We concluded that lowering the Hct by PPET in polycythaemic newborn infants normalises the CBFV after 3 hours and this remains constant up to 24 hours. This could help to clarify indications to PPET in polycythemic newborns.

Effects of Neonatal Polycythemia and Partial Exchange Transfusion on Cardiac Function: An Echocardiographic Study

Although infants with neonatal polycythemia and hyperviscosity often present with cardiorespiratory distress, little information is available regarding the cardiac function of such babies before or after partial exchange transfusion. To assess cardiac function, we performed M-mode echocardiograms in 19 asymptomatic newborn infants (4 to 12 hours of age) who had venous hematocrits greater than 65%. The echocardiograms were performed immediately prior to and following partial exchange transfusion and were repeated at 48 hours of age. Eighteen matched newborn controls also underwent echocardiography within the first 12 hours of life and again at 48 hours. Polycythemic newborns had elevated right ventricular preejection period to right ventricular ejection time ratios compared with controls (0.46 +/- 0.11 v 0.37 +/- 0.04, P = .002), suggestive of increased pulmonary vascular resistance. These indexes normalized following partial exchange transfusion. In addition, the polycythemic newborns were relatively bradycardic prior to exchange (116 +/- 13 beats per minute v 125 +/- 16 beats per minute, P less than .05), but heart rates normalized following the procedure. At 48 hours, the polycythemic and control groups were different only in that the mean shortening fraction of the polycythemic group was lower than that of the controls (32% +/- 4% v 36% +/- 6%, P = .02). The findings are consistent with elevated pulmonary vascular resistance associated with polycythemia and hyperviscosity. Cardiac output may be lower in polycythemic infants. The finding of reduced fractional shortening in polycythemic infants at 48 hours following partial exchange transfusion is unexplained.

Neonatal polycythemia and chest roentgenograms.

Chest roentgenograms of 34 newborns with a hematocrit of 75 or more at the age of 12 hours were studied. An analysis was made of the findings during the first four days of life and the results were compared with those of 18 newborns with a hematocrit of 65 or less. The cardiothoracic ratio (CTR) was found to be greater in the polycythemic infants than in the non-polycythemic infants, and greatest of all in infants with symptomatic polycythemia. Prominent pulmonary vascularity and pulmonary hyperaeration were seen more often in polycythemic newborns than in non-polycythemic infants. Eleven infants in the polycythemic group and three in the non-polycythemic group had some symptoms or signs.