Intravenous nicardipine for treatment of severe hypertension in children.

OBJECTIVE: To examine the effect of intravenous nicardipine in the treatment of children with severe hypertension. METHODS: The medical records of 29 children (mean age 94 months) treated with intravenous nicardipine were retrospectively reviewed. The mean duration of severe hypertension before nicardipine use was 12.5 hours. Most (74%) patients were receiving other antihypertensive agents before nicardipine. RESULTS: The initial nicardipine dose was 0.8 +/- 0.3 microg/kg/min (mean +/- SD). The mean effective dose was 1.8 +/- 1.0 microg/kg/min (range, 0.3 to 4.0). Blood pressure control was achieved within 2.7 +/- 2.1 hours after nicardipine was started. Nicardipine treatment produced a 16% reduction in systolic blood pressure, a 23% reduction in diastolic blood pressure, and a 7% increase in heart rate. Nicardipine was effective as a single agent on 26 (84%) of 31 occasions. Adverse effects included tachycardia, flushing, palpitations, and hypotension. CONCLUSIONS: When administered in the intensive care unit setting with close patient monitoring, intravenous nicardipine effectively lowered blood pressure in children with severe hypertension. Larger prospective studies should be conducted to confirm these findings.     

Intravenous Nicardipine for Treatment of Postcoarctectomy Hypertension in Children

Our objective was to evaluate the efficacy of intravenous (IV) nicardipine for the treatment of postcoarctectomy hypertension in children with coarctation of the aorta. We carried out a retrospective review in a pediatric intensive care unit at a tertiary care childrens hospital. The patients were children with coarctation of the aorta treated for postcoarctectomy hypertension. Children with postcoarctectomy hypertension defined as a systolic blood pressure >95th percentile for age measured by indwelling arterial catheter were treated with IV nicardipine. We measured change in mean arterial blood pressure (MAP), mean systolic and diastolic blood pressure, and mean heart rate (HR) from baseline after initiating treatment with IV nicardipine. The outcome measure was a reduction in MAP and mean systolic and diastolic blood pressure after treatment with IV nicardipine. During a 4-year period, 10 children met the study criteria. Median age was 3.25 months (range, 0.25 to 180 months). Initial median treatment dose of IV nicardipine was 1.0 µg/kg/min (range, 0.5 to 6 µg/kg/min); median dose used to control hypertension was 1.5 µg/kg/min (range, 0.25 to 6 µg/kg/min). Median duration of therapy was 26.3 h (range, 13 to 49 h). Treatment with IV nicardipine resulted in a 26.5% decrease in MAP from baseline during the first hour of treatment (p = 0.0006). Mean systolic blood pressure decreased from 133 to 105 mmHg (p = 0.005), and mean diastolic blood pressure decreased from 75 to 52.5 mmHg (p = 0.001) during the first hour of therapy with nicardipine. There was a significant reduction (p = 0.0005) in MAP during continued treatment with IV nicardipine. The mean HR of 150 remained unchanged during the first hour of therapy with nicardipine, and no significant change in mean HR or adverse effects was noted during continued therapy. Two children receiving other antihypertensive therapy demonstrated further reduction in their blood pressure when IV nicardipine was initiated. Tachycardia and hypotension were not observed in any child treated with IV nicardipine. We concluded that IV nicardipine reduced MAP with no significant change in mean HR and no adverse effects in patients with postcoarctectomy hypertension. Nicardipine produced a further reduction in MAP in children receiving other antihypertensive agents. Nicardipine is an effective agent for treatment of postcoarctectomy hypertension in children with coarctation of the aorta.     

Morphine increases synchronous ventilation in preterm infants

Objectives: To examine the short-term cardiorespiratory effects of intravenous morphine infusion in ventilated preterm infants.
Methodology A randomized double-blind placebo-controlled trial in a neonatal intensive care unit. Twenty-six preterm infants (29-36 weeks gestation) with hyaline membrane disease requiring ventilatory assistance on the first day after birth were included in the study. A loading dose of morphine 100 μg/kg over 30 min followed by a continuous intravenous infusion at 10 μg/kg per hour was given. Primary measures were heart rate, blood pressure, respiratory rate and interaction of spontaneous respiration with mechanical ventilation. Secondary measures were durations of oxygen therapy, ventilator therapy and hospitalization as well as incidence of bronchopuimonary dysplasia, periventricular haemorrhage and pneumothorax.
Results Morphine-treated infants spent a significantly greater percentage of total ventilated time breathing in synchrony with their ventilators (median [IQ]= 72[58-87] vs 31 [17-51]%; P = 0.0008). Heart rate and respiratory rate, but not blood pressure, were reduced in morphine-treated infants. Duration of oxygen therapy was reduced (median [IQ]= 4.5[3-7] vs 8[4.75-12.5] days; P = 0.046).
Conclusions Intravenous morphine infusion increases synchronicity of spontaneous and ventilator-delivered breaths in preterm infants. Morphine reduces heart rate and respiratory rate without reducing blood pressure, and may help to reduce duration of oxygen therapy in preterm infants with hyaline membrane disease.     

Randomized trial of high-frequency oscillatory ventilation versus conventional ventilation: effect on systemic blood flow in very preterm infants

OBJECTIVE: Low superior vena cava (SVC) flow is common in very preterm infants in the first day and strongly associated with periventricular hemorrhage and disability. We examined the effect of high-frequency oscillatory ventilation (HFOV) compared with conventional ventilation (CV) on SVC flow and right ventricular output. METHODS: Forty-five infants <29 weeks were randomized before 1 hour of age to HFOV or CV. Echocardiography was performed on 43 infants at 3, 10, and 24 hours of age. Infants with low SVC flow (<50 mL/kg/min) or hypotension (mean blood pressure < or =20) were treated with volume and inotrope. RESULTS: Infants allocated to HFOV (n=23) and to CV (n=20) were well matched. There was a nonsignificant trend toward more infants on HFOV having SVC flow <50 mL/kg/min (48% vs 20%) and receiving volume and inotropes (61% vs 40%). There were no significant differences in mean SVC flow or right ventricular output at 3, 10, or 24 hours. Infants on HFOV had a significantly higher calculated upper body vascular resistance at 10 hours and mean blood pressure at 24 hours. CONCLUSIONS: There were no significant adverse effects of HFOV on systemic blood flow in very preterm infants during the first 24 hours of life.     

Changes in oxygenation and pulmonary haemodynamics in preterm infants treated with inhaled nitric oxide

AIM—To investigate changes in various cardiorespiratory variables with inhaled nitric oxide (NO), as part of a randomised controlled trial.METHODS—Infants were treated with inhaled NO for 72 hours. Changes in oxygenation were assessed using the oxygenation index (OI). Serial changes in pulmonary artery pressure (PAP) were assessed using the Doppler derived acceleration time to right ventricular ejection time ratio (AT:RVET). Doppler measurements of right ventricular output, pulmonary blood flow, and systolic PAP was performed in a subset of infants.RESULTS—Twenty infants received inhaled NO and 22 acted as controls. Infants were treated at a median dose of 5 (range 5 to 20) ppm. There was a fall in median OI by 17% in treated infants within 30 minutes of treatment. The fall in OI in treated infants was significantly different from the response in controls until 96 hours. Infants treated with inhaled NO showed a rapid response with a median rise in AT:RVET of 0.04 (range ?0.06 to 0.12) within 30 minutes. The change in AT:RVET was significantly different from controls until 4 hours. Median systolic PAP also fell in treated infants by 6.1 (range ?14.4 to ?4.4) mm Hg within 1 hour. Changes in OI were significantly associated with changes in PBF (r = 0.44), but not with changes in AT:RVET.CONCLUSION—Treatment with inhaled NO rapidly improves oxygenation and lowers PAP in preterm infants. However, these effects are transient and treatment does not influence long term outcome.     

Effect of phototherapy on blood endothelin and nitric oxide levels: clinical significance in preterm infants

Background  Phototherapy may have an adverse effect on the hemodynamics of preterm infants, and endothelin (ET) and nitric oxide (NO) are both the powerful vasoactive substances. This study was designed to observe the effect of phototherapy on blood levels of ET and NO in preterm infants. Methods  Sixty-four preterm infants with hyperbilirubinemia requiring phototherapy were studied. Among them, 31 patients were born at 32–36 weeks’ gestational age (GA), and 33 patients were ≤32 weeks GA. Control group included 26 full-term infants with hyperbilirubinemia requiring phototherapy. All patients were treated with continuous phototherapy for 24 hours. Blood samples were collected before and after phototherapy. The amount of ET in the blood samples was determined by radioimmunoassay, and NO levels were determined using nitrate reductase. Heart rate, respiratory rate, apnea, and mean arterial blood pressure (MABP) were monitored regularly (defined interval: hourly, 4 hours, etc) during phototherapy. Results  Blood ET levels measured after 24 hours of phototherapy were higher than the pretreatment values, as were blood NO levels measured after 12 hours and 24 hours of phototherapy. Both increases were statistically significant (P<0.05) in the GA≤32 weeks group. In the GA>32 weeks group, blood NO levels measured after 24 hours of phototherapy were higher than the pretreatment values; these changes were also statistically significant (P<0.05). In the GA≤32 weeks group, heart rate increased and the MABP decreased during phototherapy. The changes after 24 hours of phototherapy compared to the pretreatment values were statistically significant. A few episodes of apnea occurred during phototherapy in the GA≤32 weeks group. This was significantly higher than that in the other two groups. Conclusions  Under phototherapy, blood levels of ET and NO were significantly higher in preterm infants, especially in preterm infants of ≤32 weeks GA.     

胎龄≤32周早产儿低血糖的危险因素分析

目的 探讨胎龄≤32周早产儿出生后发生低血糖的危险因素。方法 回顾性纳入2017年1月至2020年6月入住新生儿重症监护病房的86例胎龄≤32周低血糖早产儿作为低血糖组,随机选取同期住院监测血糖正常的早产儿172例为对照组。采用单因素分析与多因素logistic回归分析筛选早产儿低血糖的危险因素。结果 研究期间早产儿共计515例,其中低血糖86例（16.7%）。低血糖组小于胎龄儿（SGA）、剖宫产出生、孕母高血压、产前使用激素的比例均高于对照组（P < 0.05）,而出生体重及血糖检测前已静脉使用葡萄糖的比例均低于对照组（P < 0.05）。SGA（OR=4.311,95% CI：1.285~14.462）、孕母高血压（OR=2.469,95% CI：1.310~4.652）和产前使用激素（OR=6.337,95% CI：1.430~28.095）为早产儿低血糖的危险因素（P < 0.05）,静脉使用葡萄糖（OR=0.318,95% CI：0.171~0.591）为早产儿低血糖的保护因素（P < 0.05）。结论 SGA、孕母高血压和产前使用激素可增加胎龄≤32周早产儿早期发生低血糖的风险;对胎龄≤32周早产儿,建议生后尽早静脉使用葡萄糖,以减少低血糖的发生。     

Comparison of ibuprofen and indomethacin therapy for patent ductus arteriosus in preterm infants

BACKGROUND: Patent ductus arteriosus (PDA) is commonly found in very low-birthweight (VLBW) infants. The presence of respiratory distress syndrome (RDS) is also associated with increased frequency of significant PDA. Intravenous indomethacin has been used to treat and to prevent PDA in premature infants since 1976. However, concern remains regarding the safety of indomethacin, which affects renal, gastrointestinal and cerebral perfusion. Intravenous ibuprofen has recently been used to treat and to prevent PDA premature infants with PDA without reducing cerebral blood flow or affecting intestinal or renal hemodynamics. The aim of the present study is to compare intravenous ibuprofen and indomethacin with regard to efficacy and safety for the early treatment of PDA in preterm infants. METHODS: A total of 63 preterm infants with RDS who had a birthweight of < or =1500 g and gestational age of < or =32 weeks, were enrolled in the present study. All patients were treated with nasal continuous positive airway pressure with additional oxygen supply in inspired air>30%, or with mechanical ventilation. The patients' serum platelet counts were>100,000/uL, and serum creatinine values were <1.5 mg/dL. There were no 3-4 grade intraventricular hemorrhages before randomization, and all patients were aged 2-7 days and had echo-cardio-graphic evidence of significant PDA. Patients were randomized into two groups: the first group of neonates (group A, n = 32) received intravenous ibuprofen lysine 10 mg/kg, followed by 5 mg/kg after 24 and 48 h; the second group (group B, n = 31) received intravenous indomethacin 0.2 mg/kg every 12 h for three doses. RESULTS: Patent ductus arteriosus closed in 27 patients from the ibuprofen group (84.4%) and in 25 patients from the indomethacin group (80.6%). PDA reopened in three patients from the ibuprofen group (9.4%) and in three patients from the indomethacin group (9.7%). One patient in the ibuprofen group and two patients in the indomethacin group required ductal ligation. Serum creatinine and blood urea nitrogen (BUN) concentrations were lower in the ibuprofen group than in the indomethacin group. Urine output and creatinine clearance values were higher in the ibuprofen group than in the indomethacin group. CONCLUSIONS: Ibuprofen therapy is as efficacious as indomethacin for the treatment of PDA in preterm infants. Infants treated with ibuprofen have higher creatinine clearance and urine output and lower serum creatinine and BUN values than infants treated with indomethacin.     

不同胎龄早产儿生后24 h内血小板及相关参数参考范围

目的 研究不同胎龄早产儿生后24 h内血小板及相关参数参考范围并探讨其临床意义。方法 根据纳入标准和排除标准,收集2018年1~12月入住新生儿重症监护室且出生胎龄为23~36⁺⁶周早产儿1 070例的临床资料进行回顾性分析,观察生后24 h内不同胎龄早产儿血小板参数参考范围。结果 不同胎龄早产儿血小板计数（PLT）及血小板压积（PCT）水平比较差异无统计学意义（P > 0.05）;晚期早产儿组（34~36⁺⁶周,n=667）血小板平均体积（MPV）及血小板体积分布宽度（PDW）均低于极早早产儿组（23~27⁺⁶周,n=36）和早期早产儿组（28~33⁺⁶周,n=367）（P < 0.05）。不同性别早产儿之间血小板及相关参数比较差异均无统计学意义（P > 0.05）。按照不同胎龄来计算早产儿血小板参数的参考范围,23~36⁺⁶周早产儿PLT参考范围为（92~376）×10⁹/L,PCT参考范围为0.1%~0.394%;23~33⁺⁶周早产儿MPV参考范围为9.208~12.172 fl,PDW参考范围为8.390%~16.407%;34~36⁺⁶周早产儿MPV参考范围为9.190~11.950 fl,PDW参考范围为9.046%~15.116%。结论 不同胎龄早产儿生后24 h内MPV及PDW不同,依据胎龄制定早产儿MPV及PDW参考范围更有助于指导临床工作。     

A single very early dexamethasone dose improves respiratory and cardiovascular adaptation in preterm infants.

OBJECTIVES: To test the hypothesis that a single dose of dexamethasone given soon after delivery to infants <28 weeks' gestation leads to improved cardiopulmonary adaptation in the first week and lowers the risk of significant intraventricular hemorrhage. METHODS: In a prospective, blinded, placebo-controlled study, we randomly assigned 70 infants <28 weeks' gestation who were born in the hospital to receive dexamethasone (0.2 mg/kg) (n = 37) or normal saline solution (n = 33) within 2 hours of delivery. After an interim analysis showed that the incidence of intraventricular hemorrhage was much lower than expected, enrollment was stopped and we limited our analysis to a comparison of ventilator settings, blood pressure, and pressor use during the first 7 days. RESULTS: Clinical characteristics of the groups were comparable at study entry. Ventilator weaning occurred more rapidly in the patients who received dexamethasone: their intermittent mandatory ventilation rate was significantly lower on days 1 through 6, and their peak inspiratory pressure was lower on days 3 through 7 compared with the control group. Mean blood pressures were higher in the dexamethasone group within 12 hours and remained higher through day 5, but the use of pressors was not different. Fewer infants in the dexamethasone group received indomethacin to treat a patent ductus arteriosus (22% vs 47%, P <.03). CONCLUSION: Dexamethasone given within 2 hours of delivery to preterm infants <28 weeks' gestation resulted in lower ventilator settings and higher mean blood pressures during the first 7 days. Fewer infants required indomethacin to treat a patent ductus arteriosus.     

Intravenously administered labetalol for treatment of hypertension in children.

Thirteen children (ages 9.2 +/- 3.7 years, mean +/- SD) received intravenous doses of labetalol, an alpha 1- and beta-adrenergic blocker, on 15 separate occasions for treatment of hypertension. In 12 of 15 episodes an initial dose of 0.55 +/- 0.34 mg/kg was given; in all 15 a continuous infusion of 0.78 +/- 0.39 mg/kg per hour was utilized for 67.3 +/- 57.1 hours. A significant decrease in systemic blood pressure occurred in all episodes (143/99.1 +/- 17.7/11.1 vs 115.6/72.4 +/- 7.7/9.5; p less than 0.01). A clinically unimportant yet statistically significant decrease in heart rate occurred during labetalol infusion (116.3 +/- 19.8 vs 107.8 +/- 11 beats/min; p less than 0.01). The episodes in children with creatinine clearances greater than 50 (n = 6) were compared with those with creatine clearances less than 20 ml/min per 1.73 m2 (n = 9); similar doses of labetalol were required for control of blood pressure. We conclude that infusion of labetalol is effective for control of blood pressure in children with hypertension, regardless of renal function.     

胎龄≤32周早产儿低血糖的危险因素分析

目的 探讨胎龄≤32周早产儿出生后发生低血糖的危险因素。方法 回顾性纳入2017年1月至2020年6月入住新生儿重症监护病房的86例胎龄≤32周低血糖早产儿作为低血糖组,随机选取同期住院监测血糖正常的早产儿172例为对照组。采用单因素分析与多因素logistic回归分析筛选早产儿低血糖的危险因素。结果 研究期间早产儿共计515例,其中低血糖86例（16.7%）。低血糖组小于胎龄儿（SGA）、剖宫产出生、孕母高血压、产前使用激素的比例均高于对照组（P < 0.05）,而出生体重及血糖检测前已静脉使用葡萄糖的比例均低于对照组（P < 0.05）。SGA（OR=4.311,95% CI：1.285~14.462）、孕母高血压（OR=2.469,95% CI：1.310~4.652）和产前使用激素（OR=6.337,95% CI：1.430~28.095）为早产儿低血糖的危险因素（P < 0.05）,静脉使用葡萄糖（OR=0.318,95% CI：0.171~0.591）为早产儿低血糖的保护因素（P < 0.05）。结论 SGA、孕母高血压和产前使用激素可增加胎龄≤32周早产儿早期发生低血糖的风险;对胎龄≤32周早产儿,建议生后尽早静脉使用葡萄糖,以减少低血糖的发生。     

Randomised controlled study of early use of inhaled corticosteroid in preterm infants with respiratory distress syndrome

AIM: To investigate the therapeutic efficacy of inhaled fluticasone propionate, started on day 1 of age, on ventilated preterm infants with respiratory distress syndrome. METHODS: Starting within 24 hours of age, ventilated preterm infants (gestation < 32 weeks, birthweight < 1.5 kg) with respiratory distress syndrome were given a 14 day course (two puffs, 12 hourly) of either fluticasone propionate (250 microg/puff) (group 1, n=27) or placebo (group 2, n=26) with a metered dose inhaler-spacer device. Response to treatment was assessed by the rate of successful extubation by days 7 and 14 of age, changes in respiratory system mechanics, death, occurrence of chronic lung disease, and other neonatal complications. RESULTS: More infants in the treatment group were successfully extubated by 14 days of age than those in the placebo group (17/27 vs 8/26; p = 0.038). The treated infants also showed a more significant improvement in respiratory system compliance during the first 14 days of life. The two groups, however, did not differ significantly in their need for systemic steroids after day 14 of age, death, or the occurrence of chronic lung disease. The treatment was not associated with any increase in neonatal complications, including those attributable to steroid induced side effects. CONCLUSION: These results provide preliminary evidence that early treatment with inhaled corticosteroids may be beneficial to ventilated preterm infants with respiratory distress. Further study of its use in a large scale randomised trial is warranted.     

Effect of single and multiple courses of prenatal corticosteroids on 17-hydroxyprogesterone levels: implication for neonatal screening of congenital adrenal hyperplasia

Measurement of 17-hydroxyprogesterone (17-OHP) from filter-paper blood is widely used to screen for congenital adrenal hyperplasia (CAH). However, in pregnancies with an expected preterm delivery, prenatal treatment with steroids to induce pulmonary maturation could suppress the fetal adrenals and interfere with this screening. In 160 infants who were born between 25 and 35 wk of gestation, we measured 17-OHP in filter-paper blood at 72-96 h and compared the values between those who had not received antenatal steroids (n=50) and those who had (n=110). A single course of steroids was two 12-mg injections of betamethasone given within a 24-h interval: 30 infants received a half single course, 45 received a full single course, and 35 received multiple courses. Results are expressed as medians (25th percentile; 75th percentile). Blood 17-OHP differed significantly among groups: 23.7 (14.2; 30.7) nmol/L, 26.1 (15.0; 50.1) nmol/L, 20.1 (13.8; 29.1) nmol/L, and 14.9 (9.5; 26.2) nmol/L (for, respectively, no steroid, half a single course, a full single course, and multiple courses; p <0.05, multiple comparisons with the Kruskal-Wallis test). However, only infants who were treated with multiple antenatal courses of steroids had lower blood 17-OHP than those who were untreated (p <0.05 with the Mann-Whitney U test). In multiple regression analysis, steroid treatment and intrauterine growth retardation were significant negative predictors of blood 17-OHP, whereas respiratory distress syndrome was a significant positive predictor (multiple R=0.50, p <0.001). Multiple courses of steroids in preterm infants decrease 17-OHP values by approximately 30% in filter-paper blood, thus raising the risk of false-negative results in screening programs for CAH.     

胎龄<32周早产儿中重度支气管肺发育不良危险因素的多中心回顾性分析

目的 分析胎龄<32周早产儿中重度支气管肺发育不良（bronchopulmonary dysplasia,BPD）的危险因素。 方法 回顾性收集2019年1月1日至2020年12月31日江苏省新生儿围产期协作网17家单位新生儿重症监护室收治的胎龄<32周且住院时间≥28 d诊断为BPD早产儿的临床资料,依据胎龄和BPD严重程度分组,采用多因素logistic回归分析不同胎龄段发生中重度BPD的危险因素。 结果 2年间17家协作单位新生儿重症监护室收治的胎龄<32周早产儿共2 603例,诊断BPD的961例,BPD发生率为36.92%（961/2 603）,中重度发生率为8.64%（225/2 603）,24⁺⁰~25⁺⁶周早产儿中重度BPD发生率为56.5%（26/46）,26⁺⁰~27⁺⁶周早产儿中重度BPD发生率为31.0%（66/213）,28⁺⁰~29⁺⁶周早产儿中重度BPD发生率为16.9%（75/445）,30⁺⁰~31⁺⁶周早产儿中重度BPD发生率为22.6%（58/257）。多因素logistic回归分析显示,各胎龄段早产儿中重度BPD危险因素不尽相同：24⁺⁰~25⁺⁶周为需治疗的动脉导管未闭;26⁺⁰~27⁺⁶周为胎膜早破≥18 h、复苏正压通气、临床败血症、机械通气时间≥14 d;28⁺⁰~29⁺⁶周为机械通气时间≥14 d、新生儿肺炎、需治疗的动脉导管未闭;30⁺⁰~31⁺⁶周为复苏正压通气、新生儿肺炎、早产儿贫血（均P<0.05）。 结论 胎龄<32周早产儿中重度BPD是多种因素共同作用的结果,并且每个胎龄段存在不尽相同的高危因素,对不同胎龄段提前采取有针对性举措,将有助于减轻BPD严重程度。     

Intravenous immune globulin versus intravenous anti-D immune globulin for the treatment of acute immune thrombocytopenic purpura

Objective  The purpose of this study was to compare the efficacy and side effects of intravenous immunoglobulin (IVIG) with intravenous anti-D immunoglobulin for treatment of newly diagnosed acute childhood Idiopathic thrombocytopenic purpura (ITP). Methods  Children (6 months to 14 years) with newly diagnosed acute ITP and platelet count below 20,000/ μL were randomized to receive single dose intravenous 75 μg/kg anti-D or 1g/kg IVIG for two consecutive days (total dose 2 g/kg). Response rate defined as a platelet count over 20,000 / μL 72 hours after initial treatment. Results  Eighty one patients (52 male and 29 female) with mean age of 5 years and 3 months randomly divided in anti-D group (n=42) and IVIG group (n=39). Mean baseline (pretreatment) platelet counts were 15406 / μL and 15230/ μL in anti-D and IVIG group, respectively. The response rate in IVIG group (98%) was more significant than anti-D group (76%); (P = 0.017). After 7 days the platelet counts of all patients in IVIG group were more than 20,000/ μL while in anti-D group 12% had platelet counts below 20,000/ μL. Conclusion  In acute childhood ITP, initial treatment with IVIG (2g/Kg in divided dose) increased platelet count more rapidly and more significant than intravenous anti-D (single dose of 75 μg/Kg) within the first 72 hours.     

Low systemic blood flow and hyperkalemia in preterm infants

OBJECTIVE: Early low systemic blood flow is common in preterm infants. This study examines the relationship among low flow, renal function, and early changes in blood potassium (K(+)). METHODS: Preterm infants (n = 119) born before 30 weeks' gestational age underwent serial Doppler echocardiographic studies. Superior vena cava flow (SVC flow) was assessed as a measure of upper body systemic blood flow uncorrupted by systemic to pulmonary shunts. Serial whole blood K(+) concentrations on each arterial blood gas sample and urinary output in the first 48 hours were recorded. RESULTS: Most infants had a variable degree of rise in K(+) during the first 24 hours of life. The mean rate of rise was 0.17 mmol/L/h, the mean peak K(+) was 5.54 mmol/L, and the mean time of peak K(+) was 20 hours. The peak K(+) occurred after the lowest measured SVC flow in 84% of infants. A significant positive relationship was found between the lowest measured SVC flow and the mean (r = 0.31, P =.001) and peak (r = 0.31, P =.001) K(+) in the first 24 hours. Low SVC flow at 5 hours best predicted the rate of K(+) rise (r = 0.28, P =.002) and at 12 hours best predicted the peak K(+) concentration (r = 0.47, P <.001). The mean minimum SVC flow in the 17 babies who became hyperkalemic was 29.5 mL/kg/min versus 46.2 mL/kg/min in the 102 infants with normokalemia. Urine output in the first 24 hours was significantly lower in the hyperkalemic infants. A K(+) rate rise exceeding 0.12 mmol/L/h in the first 12 hours predicted low SVC flow with 93% accuracy. CONCLUSIONS: The data are consistent with a role for low systemic blood flow leading to reduced urinary output and subsequent hyperkalemia in preterm infants.     

Comparing alloimmunization in preterm infants after transfusion of fresh unmodified versus stored leukocyte-reduced red blood cells.

PURPOSE: To compare the occurrence of red blood cell (RBC), platelet (PLT), and white blood cell (WBC) antibodies in preterm infants after transfusions. METHODS: A randomized, blinded trial was conducted in which preterm infants were transfused either with stored RBCs, prepared by prestorage leukocyte reduction and transfused throughout 42 days of storage to limit donor exposure (n = 18), or with fresh RBCs prepared without leukocyte reduction and transfused within 7 days after collection from as many donors as needed to guarantee freshness (n = 17). Nontransfused preterm infants of comparable birth weight were control subjects (n = 11). RESULTS: No RBC antibodies were detected in serial blood samples taken during the first 6 months of life. Similarly, no definite WBC antibodies were found, although weak reactivity was detected transiently in sera from two infants. Accordingly, RBC and WBC antibody production did not differ among groups. In all, 11% of the transfused the infants exhibited platelet antibodies: 14% of the infants given stored leukocyte-reduced RBCs and 7% of the infants given fresh nonleukocyte-reduced RBCs (difference not statistically significant). CONCLUSIONS: Preterm infants rarely produce antibodies to blood cell antigens after RBC transfusions, regardless of whether the exposure is to fresh unmodified RBCs from several donors or to stored leukocyte-reduced RBCs from a limited number of donors. Therefore, efforts to limit donor exposures or to remove WBCs from blood components cannot be justified simply for purposes of preventing alloimmunization in neonates.     

妊娠期高血压疾病对胎龄28~34周早产儿外周静脉血细胞计数的影响

目的 探讨母亲妊娠期高血压疾病（hypertensive disorders of pregnancy,HDP）对胎龄28~34周早产儿外周静脉血细胞计数的影响。 方法 选取2020年1~12月昆明医科大学第一附属医院儿科收治的母亲合并HDP的胎龄28~34周早产儿227例为研究组,另选取同期收治的母亲无HDP的胎龄28~34周早产儿227例为对照组。研究组根据母亲妊娠期血压分为妊娠期高血压亚组（75例）、轻度子痫前期亚组（81例）、重度子痫前期亚组（71例）;根据早产儿出生体重分为小于胎龄儿（small for gestational age,SGA）亚组（113例）及适于胎龄儿（appropriate for gestational age,AGA）亚组（114例）。比较研究组和对照组、研究组各亚组间早产儿生后第1天外周血细胞计数的差异。 结果 研究组患儿生后第1天外周静脉血白细胞（white blood cell,WBC）计数、中性粒细胞绝对计数（absolute neutrophil count,ANC）及血小板（platelet,PLT）计数均低于对照组（P<0.05）,白细胞减少症、中性粒细胞减少症发生率高于对照组（P<0.05）。亚组分析中,轻度子痫前期亚组、重度子痫前期亚组WBC计数、ANC、PLT计数均低于妊娠期高血压亚组（P<0.05）;SGA亚组WBC计数、ANC、PLT计数低于AGA亚组（P<0.05）。 结论 HDP可对早产儿外周静脉血细胞计数产生影响,这一影响在母亲子痫前期及SGA早产儿中更为显著。     

Nitric oxide production and plasma cyclic guanosine monophosphate in premature infants with respiratory distress syndrome

A low blood pressure is common in preterm infants with respiratory distress syndrome (RDS). A diminished vascular resistance appears to be an important cause. The endogenous production of nitric oxide (NO), a mediator of vascular smooth muscle relaxation, has been shown to be higher in infants with RDS than in those without. Infants with persistent pulmonary hypertension showed decreased endogenous NO levels as compared with controls. Severe RDS in preterm infants may be accompanied by persistent pulmonary hypertension. To elucidate the role of NO in RDS and low blood pressure, we determined the endogenous NO production in infants with and without RDS by measuring urinary nitrite and nitrate excretions and plasma cGMP levels. In consecutively admitted preterm infants (gestational age <32 weeks), urine samples for measurement of NO(2) and NO(3) and plasma samples for the determination of the cGMP concentrations were serially collected during the 1st week of life. Arterial blood pressure, therapy to support blood pressure, and additional relevant clinical data were registered simultaneously. 27 infants with and 39 without RDS were included. The urinary NO(x) levels increased in all patients and were not different between both groups. The plasma cGMP concentrations were higher in the RDS group on days 2, 3, 4, and 7 (p < 0.05). The severity of RDS was positively correlated with plasma cGMP (r = 0.50, p = 0.0001). Although the arterial blood pressure did not differ between the groups, more blood pressure support was needed in the RDS infants during the first 4 days (p < 0.05). A positive correlation was found between blood pressure support and plasma cGMP (r = 0.34, p < 0.0001). The endogenous NO production was not different in infants with and without RDS. Increased plasma cGMP levels in the RDS infants were associated with the severity of RDS and the intensity of antihypotensive treatment. The origin of cGMP in infants with RDS requires further research.