Estimation of 24-hour energy expenditure from shorter measurement periods in premature infants

We performed continuous indirect calorimetry for 24 h on nine occasions in small premature infants. Oxygen consumption, carbon dioxide production, respiratory quotient, and energy expenditure were calculated for each 2-h period. The mean energy expenditure during the first 6 h was within 6.5% of the mean for the whole 24-h period in all but one case. The mean error in estimating total daily energy expenditure from 6-h measurements was 0.9%. Because positive and negative errors tend to offset each other, we also calculated the mean absolute error, which was 5.6%. The mean coefficient of variation in energy expenditure among the 2-h periods was 11.0%. The mean coefficients of variation in oxygen consumption, carbon dioxide production, and respiratory quotient were 12.8, 9.9, and 14.1%, respectively. Total daily energy expenditure of small premature infants can be estimated from measurements as short as 6 h with sufficient accuracy for most purposes.     

12-hour versus 24-hour creatinine clearance in critically ill pediatric patients

Measurement of renal function is important to optimize drug dosing in critically ill pediatric patients and to prevent dose-related toxicities caused by medications that are eliminated or metabolized by the kidney. In clinical practice, the 24-h creatinine clearance (CrCl) is used as a surrogate marker of renal function. However, a 24-h urine collection period delays the availability of the result and increases the potential for collection errors. This prospective, observational study was performed to determine whether a 12-h CrCl is comparable to the traditional 24-h CrCl and to assess whether CrCl could be reliably predicted by the Schwartz equation, which mathematically estimates a child's GFR. A 24-h urine sample was collected in two 12-h aliquots from 60 catheterized critically ill children (age 2 d to 18 y). CrCl and Schwartz glomerular filtration rate (GFR) estimates were determined for each 12- and 24-h period. Agreement between 12- and 24-h CrCl and between CrCl and Schwartz GFR estimates was assessed using intraclass correlation coefficients (ICCs). An ICC > or =0.8 was considered to indicate excellent agreement. The ICC between the first 12-h CrCl and 24-h CrCl was 0.9605. The ICC between the second 12-h CrCl and 24-h CrCl was 0.9602. The ICC between the 24-h CrCl and Schwartz GFR was only 0.7046. All comparisons of 12- and 24-h CrCl indicated excellent agreement. In summary, the Schwartz equation was not a reliable estimate of renal function in critically ill children, and a 12-h CrCl is just as accurate as the standard 24-h CrCl to assess renal function and guide drug dosing.     

24-hour behavioural states distribution in continuously fed infants

This study compared the 24-h sleep states distribution in infants fed orally with separate meals with that in infants continuously fed from birth. Sleep was polygraphically recorded for 24 h in 12 infants (aged between 6 weeks and 14 months) continuously fed since birth through an intracaval catheter, and in 12 age-paired control infants. The amount of sleep states in each six 4-h epoch of the 24-h day was evaluated. A clear decrease of the sleep amount, concerning both Paradoxical Sleep and Quiet Sleep, was observed during the day-time in infants older than 4 months, independently from the feeding condition. This result does not support the role of feeding rhythm upon the early development of sleep pattern circadian distribution.     

Fat-derived fuels during a 24-hour fast in children

We examined the availability of fat-derived fuels in 23 normal children aged 1.9 to 16.7 years who fasted for 24 h. we found a rapid and progressive rise in the blood concentrations of free fatty acids (FFA) and ketones. There was a highly significant negative correlation between the concentrations of -hydroxybutyrate (OHB) and glucose and also between OHB and age.With time, the ratio of OHB to acetoacetate (AcAc) progressively increased.We briefly review the vital role of ketones in the adaptation to fasting and point out that qualitative tests of ketones can be misleading. Our results indicate that quantitative determinations are essential in the evaluation of suspected disorders of fuel metabolism and that the results must be interpreted according to the age of the child, the duration of fasting, and the concomitant concentrations of glucose.Presented in part at the annual meeting of the American Pediatric Society and Society for Pediatric Research, San Francisco, April 1981     

儿童心肌炎动态心电图监测临床价值探讨

目的：目前诊断病毒性心肌炎的标准仍是采用临床、心脏器械和实验室检查相结合的方法综合判断。该文对儿童心肌炎动态心电图(DCG)监测下心电变化特点作一回顾性分析,旨在为临床诊断、治疗及预后判断提供重要依据。方法：分析59例儿童心肌炎及41例无器质性心脏病对照组的心电图变化,测定DCG异常率、室性早搏数量、级别及分布情况、心率变异指标。 结果：心肌炎组异常DCG检出率86.4%,且部分为复合心律失常,与对照组DGC异常检出率46.3%相比,差异非常显著﹙P<0.01﹚。室早分布类型心肌炎组以均匀型（84.6%﹚及单峰型﹙64.4%﹚最常见,与对照组比较差异有显著性﹙P<0.05,P<0.01﹚。 结论： 儿童DCG监测异常、早搏分布为均匀型、早搏高峰为单峰及多峰型者或出现复合心律失常对儿童心肌炎的诊断、治疗及预后判断有一定参考价值。［中国当代儿科杂志,2007,9（3）：213-215］     

新生儿胃食管返流的24小时食管内pH监测

目的探讨新生儿胃食管返流食管内pH的变化及其临床意义。方法疑诊为新生儿胃食管返流36例，以无症状新生儿15例作对照。用便携式24小时食管、胃pH自动记录仪（Digitrapper型）在常态下作24小时食管内pH监测。食管pH降至4以下持续15秒钟以上定义为一次返流。结果疑诊为新生儿胃食管近流的36例中14例Boix－Ochoa评分＞11．99为病理性返流，22例为生理性返流。15例对照组中2例为生理性返流，13例为正常。结论24小时新生儿食管内pH监测为早期诊断新生儿胃食管返流提供客观依据。     

Efficacy of 24-hour ambulatory blood pressure monitoring in children

OBJECTIVES: To determine whether the use of an ambulatory blood pressure monitor (ABPM) is feasible and gives accurate readings in children, and to provide data on normal daily blood pressures (BPs) and BP patterns in children. DESIGN: Cohort. SUBJECTS: Ninety-nine healthy fifth-grade students. INTERVENTIONS: Students wore an ABPM for 24 hours while recording their activities in diaries. Before and after the study period, each subject had three BPs simultaneously measured with the ABPM and a mercury manometer to assess the accuracy of the ABPM. An activity scale was retrospectively applied to diary entries to help explain the variety of BP patterns noted during data analysis. RESULTS: Systolic BPs obtained with the ABPM at the beginning and end of the study were slightly higher than those obtained with a mercury manometer; diastolic BPs were virtually identical. A circadian pattern of BPs was noted: mean systolic and diastolic BPs were higher during the day than at night. The BP patterns ranged from "hypoactive" (little baseline variation) to "hyperactive" (wide fluctuations with spikes to elevated BP ranges) during various activities. In general, higher BPs were noted at times of increased activity or emotional levels. CONCLUSIONS: Ambulatory BP monitoring was well tolerated, and measurements were reproducible and accurate. The variety of BP measurements noted at different activity levels indicate that a child's activity should be considered during data analysis. As further experience is gained, the ABPM should prove helpful in diagnosis and management of hypertension in children.     

Influence of 24-hour sleep deprivation on respiration in lambs

The aim of this study was first to examine the effects of 24-h sleep deprivation on apnea index and duration in lambs. The effects on sleep architecture and sigh and swallowing indices were also studied. The impact of postnatal maturation on all measured variables was assessed by studying two different age groups. Twelve lambs (six aged 1-2 d and six aged 23-24 d on the day of surgery) were chronically instrumented for polysomnographic recordings including sleep state assessment, nasal flow, diaphragm electromyogram, and glottal constrictor muscle electromyogram. Two recordings, one control and one after 24-h sleep deprivation, were performed in all lambs. Results show that the effects of sleep deprivation predominate in rapid eye movement sleep in the younger group, with increased rapid eye movement sleep proportion and apnea, sigh, and swallowing index. Our results in lambs suggest that the consequences of sleep deprivation upon respiration are predominant early after birth. Although the potential relationship of these observations to neonatal apneas and sudden infant death syndrome has yet to be defined, awareness of the effects of sleep deprivation is important for neonatal care.     

The validity of a structured interactive 24-hour recall in estimating energy and nutrient intakes in 15-month-old rural Malawian children

This study aimed to compare the nutritional intake values among 15-month-old rural Malawian children obtained by weighed food record (WFR) with those obtained by modified 24-hour recall (mod 24-HR), and to develop algorithm for adjusting mod 24-HR values so as to predict mean intake based on WFRs. The study participants were 169 15-month-old children who participated in a clinical trial. Food consumption on one day was observed and weighed (established criterion) by a research assistant to provide the estimates of energy and nutrient intakes. On the following day, another research assistant, blinded to the direct observation, conducted the structured interactive 24-hour recall (24-HR) interview (test method). Paired t-tests and scatter-plots were used to compare intake values of the two methods. The structured interactive 24-HR method tended to overestimate energy and nutrient intakes (each P < 0.001). The regression-through-the-origin method was used to develop adjustment algorithms. Results showed that multiplying the mean energy, protein, fat, iron, zinc and vitamin A intake estimates based on the test method by 0.86, 0.80, 0.68, 0.69, 0.72 and 0.76, respectively, provides an approximation of the mean values based on WFRs.     

24-hour esophageal pH-metry in the evaluation of gastroesophageal reflux pathology]

Gastro-esophageal reflux (GER) in infants was studied using 24-hour esophageal pH monitoring. Gastro-esophageal reflux was detected in 32/41 subjects. In our patients the main symptoms were vomiting, regurgitation, failure-to-thrive, chronic respiratory problems such as asthma, apnea, recurrent pneumonia. All patients with GER were treated appropriately with prone positioning and medical therapy (prokinetic agent and, eventually, ranitidine). Successful treatment of the reflux was obtained in all patients. In our opinion the 24-hour intraesophageal pH monitoring is a highly diagnostic test to identify the presence of GER and evaluate its gravity.     

24-hour electrocardiogram before and during cisapride treatment in neonates and infants

We studied prospectively the effects of cisapride on heart rate and rhythm using standard ECG and 24-hour ECG recordings in term and preterm neonates and infants. We studied subjects with gastroesophageal reflux disease (apparent life-threatening events, apneas, bradycardias) before and 3 days after starting cisapride (0.8 mg/kg/day in 4 doses). We performed standard ECGs for determination of corrected Q-T interval (QTc) and Q-T dispersion (QTd) and 24-hour ECG recordings for analysis of heart rate, heart rate variability, and heart rhythm. Fourteen term and 17 preterm subjects (gestational age range 28-36 weeks) were studied at a median chronological age of 29 (range 3-132) days. Cisapride significantly increased the QTc in preterm infants (before vs. after: 408 +/- 7 vs. 433 +/- 7 ms, p = 0.001). Two preterm and 1 term infant had a QTc >450 ms before cisapride. Four preterm (4/15 = 27%) and 2 term (2/13 = 15%) subjects had a QTc >450 ms on cisapride. After cisapride the QTd remained normal, and no relevant arrhythmias were documented on Holter recordings. Cisapride significantly decreased peak and mean heart rates of all study subjects without affecting the heart rate variability, while it increased the minimal heart rate of preterm infants only (before vs. after: 66 +/- 5 vs. 78 +/- 5 bpm, p = 0.02). The maximally measured R-R intervals (pauses) decreased after cisapride in preterm infants (before vs. after: 1.33 +/- 0.2 s vs. 1.05 +/- 0.2 s, p = 0.04). Although cisapride did cause a significant prolongation of the ventricular action potential duration in preterm infants, the QTd remained unaffected, and no clinically relevant arrhythmias were documented in this small sample. On the other hand, cisapride had a direct lowering effect on the maximal and mean heart rates of both term and preterm infants, while the drug increased the minimal heart rate and reduced the severity of bradycardia episodes in preterm infants.     

Cardiac arrhythmias in healthy children revealed by 24-hour ambulatory ECG monitoring

Summary Ambulatory electrocardiographic monitoring was performed on 360 healthy children, from newborn infants to junior high school students. They were divided into five groups by age: group A, 63 newborn infants on the first day of life; group B, 50 infants aged 1–11 months; group C, 53 kindergarten pupils aged 4–6 years; group D, 97 primary school pupils aged 9–12 years; and group E, 97 junior high school students aged 13–15 years.The maximal and minimal heart rates were significantly greater in infants than in older children. Sinus arrhythmia was recorded in every child. One boy in group E had an episode of sinus arrest for three seconds without any symptoms. First-degree and Wenckebach type second-degree atrioventricular blocks were not detected in group A and group B, but were most frequent in group E, especially during sleep. Supraventricular premature contractions (SVPCs) were the most common type of arrhythmia detected in this study. More than half of the children had at least one SVPC per 24-h monitoring period, and there were many children with frequent SVPCs in group E. The incidence of ventricular premature contractions (VPCs) in children of groups A and E was rather higher than in the other groups. Ventricular tachycardia was not recorded in any child except one newborn infant who had a couplet of VPCs without symptoms.Each group had different types and incidences of arrhythmias. There was a rising incidence of arrhythmias with advancing age, except in the neonatal period.     

青少年24小时活动与心理健康研究的范围综述

背景：由于睡眠、久坐行为和身体活动所构成的24 h活动与青少年心理健康关系的研究异质性极大等局限,难以得出足以指导临床实践的高质量证据集合。目的：总结儿童青少年24 h活动（睡眠、久坐行为和身体活动）与心理健康关系的研究现状及其研究设计存在的问题并进行评价,为后续研究提供参考。设计：范围综述。方法：检索PubMed、Embase、Web of Science和中国知网数据库,检索时间为建库至2022年9月28日,以睡眠、久坐行为、身体活动、24 h活动、心理健康、青少年为检索词构建中英文检索式,纳入健康儿童青少年人群的24 h活动类型与心理健康之间的相关性或因果推断的研究。通过阅读文题、摘要和全文进行筛选,在数据提取和数据整合中,逐渐完善活动类型、测量方式、测量项目分类、测量具体项目的数据提取表格。主要结局指标：青少年24 h活动和心理健康关系的研究类型及其测量工具。结果：中英文数据库共检索到927篇文献,经去重、初筛和全文筛选后,最终纳入55篇文献,其中横断面研究45篇（82%）,前瞻性队列研究10篇。睡眠：54篇描述了睡眠时长,4篇评估了睡眠质量、睡眠潜伏期、日间嗜睡情况和睡眠中断情况。久坐行为：50篇为主观报告,5篇为客观报告,46篇涉及屏幕暴露。身体活动：主观报告和客观评估中高强度身体活动时间分别为47篇和8篇。32篇文献关注了抑郁,9篇关注了焦虑,5篇关注了压力,35篇关注了其他心理健康结局（正性情绪、行为问题、生活满意度或健康相关生命质量、心理疾病及症状、情绪调节能力和手机成瘾）。44篇文献探索24 h活动与心理健康的相关性,8篇文献使用等时替代模型探索24 h活动结构的改变,3篇探索24 h活动影响心理健康的中介因素。结论：青少年24 h活动与心理健康的关联研究尚少,所使用的测量工具有待规范统一,未来需针对现行24 h活动推荐时间建立等时替代模型或在真实世界进行干预研究,寻找既能够最大发挥24 h活动的健康效应,又能够让青少年人容易达到的24 h活动时间的推荐组合。     

Frequency of gastroesophageal reflux in neonates as assessed by 24-hour pH monitoring

The purpose of the present study was to determine the frequency and the other characteristics of gastroesophageal reflux (GER) in 46 asymptomatic neonates during the first weeks of life. The GER were assessed by 24-hour continuous esophageal pH monitoring (CPR). The frequency of all the GER was 0.66 +/- 0.54/h (0 to 2.21). Half of the GER were determined as acid (pH less than 4 during at least 15 sec), 23% as highly acid (pH less than 3 during at least 15 sec), 39% as weakly acid (abrupt fall of the pH higher than 1 unit pH), and 11% as non acid (abrupt increase of pH higher than 1 unit pH). According to these results, a CPR should be considered as pathologic in neonates when the following criteria are fulfilled (upper limits fixed at means + 2 S.D.): 1. frequency of acid GER longer than 5 min above 0.35/h; 2. time ratio at pH below 4 exceeding 10.4%; or 3. frequency of very acid GER greater than 0.53/h.     

Comparison of methods of assessing 24-hour intraesophageal pH recordings in children.

Prolonged intraesophageal pH recording, an important test in the evaluation of children with suspected gastroesophageal reflux (GER) disease, may be performed and evaluated by markedly different methodologies. Twenty-four-hour intraesophageal pH recordings from 67 consecutive infants were evaluated by three scoring methods: early postprandial, late postprandial, and total recording. In addition, the scoring methods were evaluated for their ability to identify 20 infants with clinically defined GER-induced acute life-threatening events (ALTEs). There were significant positive correlations between each pair of scoring systems (early postprandial with late postprandial, early postprandial with total recording, and late postprandial with total recording). However, our data indicate that the three methods identify different groups of patients. The early and late postprandial methods disagreed in designating "normal" versus "abnormal" in approximately 20% of patients. The total recording method was more likely to label patients as normal than either of the other methods; it yielded normal results in approximately one half of patients abnormal by either the early or the late postprandial methods. Patients with GER-induced ALTEs were identified by the early postprandial method in 90% of cases, the late postprandial method in 95% of cases, and the total recording method in only 45% of cases. By applying three different scoring methods to the same 24-h intraesophageal pH recording, we demonstrated less-than-perfect correlation among the methods. Long-term follow-up is needed to determine if these differences are of clinical significance. We feel that effort should be directed toward standardizing the approach to intraesophageal pH monitoring in infants.     

Intravenous omeprazole in children: pharmacokinetics and effect on 24-hour intragastric pH

BACKGROUND: Omeprazole is a proton pump inhibitor, acting selectively on the gastric parietal cell H+K+-adenosine triphosphatase. Data on the intravenous route are limited in children and not available in infants. OBJECTIVE: This study was designed to determine the pharmacokinetics and the optimal dosage of intravenous omeprazole in patients younger than 30 months of age. METHODS: Nine children (three girls), aged 4.5 to 27 months, with normal liver and renal functions requiring intravenous omeprazole were studied. After enrollment in the study and randomization, omeprazole was administered once daily, at 8 am, as a 1-hour infusion. Group 1, consisting of the first four patients, received 20 mg/1.73 m2, and group 2, consisting of the following five patients, received 40 mg/1.73 m2. At day 3, a 24-hour intragastric pH and a pharmacokinetic study of omeprazole were performed. Plasma concentrations were measured by high-performance liquid chromatography. RESULTS: Patients in group 2 had a significantly higher median pH (6.99 vs. 3.35; P = 0.01) and percent of monitored time with gastric pH >4 than children given 20 mg/1.73 m2 (90.6% vs. 44.8%; P < 0.01). Four had a pH more than 4 during more than 90% of the time versus none of the patients of group 1. The plasma concentration versus time curves showed rapid elimination of the drug. The median area under the curve of omeprazole was 0.78 microg. mL-1. h-1 (range, 0.55-1.64 microg. mL-1. h-1) and 3.95 microg. mL-1. h-1 (range, 1.9-4.9 microg. mL-1. h-1), respectively, in groups 1 and 2 (P < 0.05). Systemic clearance was not different between the two groups: median values were 0.68 and 0.42 L. kg-1. h-1 (P = 0.22). CONCLUSIONS: In critical situations, intravenous administration of omeprazole may be required in infants. The authors demonstrate that the dose of 20 mg/1.73 m2 is not effective in maintaining 24-hour gastric pH of more than 4 and that a dose of 40 mg/1.73 m2 is required.