Comparison between oscillometric and intra-arterial blood pressure measurements in ill preterm and full-term neonates

Conflicting data exist regarding the accuracy of the oscillometric method of blood pressure (BP) measurement in neonates. There is limited data regarding intra-arterial BP trends in neonates. We aimed to determine the accuracy of oscillometric BP measurements and to evaluate the BP distributions in ill neonates. A total of 1492 simultaneously obtained oscillometric and intra-arterial (umbilical arterial [UAC] or radial arterial) BP measurements were used for comparisons and 125,580 intra-arterial BP readings were used to the evaluate BP distribution. There was a statistically significant difference (P < .0001) between the oscillometric and radial mean arterial BP (MAP) 4.8 ± 9.8 mm Hg, systolic BP 8.3 ± 11.6 mm Hg, diastolic BP 4.3 ± 9.3 mm Hg and between the oscillometric and UAC systolic BP 5.2 ± 11.9 mm Hg and diastolic BP −0.8 ± 10.4 mm Hg. The MAP increased with increases in weight (35.3 ± 4.92 mm Hg/kg), post-menstrual age (−0.29 ± 1.41 mm Hg/week) and advanced gestational age at birth (13.12 ± 0.90 mm Hg/week). Oscillometric BP measurements are not equivalent to the intra-arterial (UAC or radial arterial) BP in ill neonates. The BP increases with increase in weight, gestational age at birth, and post-menstrual age in ill neonates.     

Conjugated hyperbilirubinemia presenting in first fourteen days in term neonates

AIM To describe the etiology and characteristics of earlyonset conjugated hyperbilirubinemia(ECHB) presenting within 14 d of life in term neonates.METHODS Retrospective review was performed of term infants up to 28-d-old who presented with conjugated hyperbilirubinemia(CHB) at a tertiary center over a 5-year period from January 2010 to December 2014. CHB is defined as conjugated bilirubin(CB) fraction greater than 15% of total bilirubin and CB greater or equal to 25 μmol/L. ECHB is defined as CHB detected within 14 d of life. Late-onset CHB(LCHB) is detected at 15-28 d of life and served as the comparison group.RESULTS Total of 117 patients were recruited: 65 had ECHB, 52had LCHB. Neonates with ECHB were more likely to be clinically unwell(80.0% vs 42.3%, P 0.001) and associated with non-hepatic causes(73.8% vs 44.2%, P = 0.001) compared to LCHB. Multifactorial liver injury(75.0%) and sepsis(17.3%) were the most common causes of ECHB in clinically unwell infants, majority(87.5%) had resolution of CHB with no progression to chronic liver disease. Inborn errors of metabolism were rare(5.8%) but associated with high mortality(100%) in our series. In the subgroup of clinically well infants(n = 13) with ECHB, biliary atresia(BA) was the most common diagnosis(61.5%), all presented initially with normal stools and decline in total bilirubin but with persistent CHB. CONCLUSION Secondary hepatic injury is the most common reason for ECHB. BA presents with ECHB in well infants without classical symptoms of pale stools and deep jaundice.     

Time-qualified reference values for 24 h ambulatory blood pressure monitoring.

BACKGROUND: The development of automatic instrumentation for ambulatory blood pressure monitoring makes it possible to follow the time-course of blood pressure variation over 24h or more in large groups of individuals. Whenever samples from a reference group of individuals are available, one may construct a prediction interval that is expected to include any single future observation from the reference population, with a specified confidence. Alternatively, the reference interval may consist of a tolerance interval that will include at least a specified proportion of the population with a stated confidence. OBJECTIVE: To examine prospectively whether a new, combined tolerance-hyperbaric test approach of establishing tolerance intervals for the circadian variability of blood pressure as a function of gestational age and then computing the hyperbaric index as a measure of blood pressure excess provides high sensitivity and specificity in the early identification of pregnant women who subsequently will develop gestational hypertension or pre-eclampsia. METHODS: We used data sampled for 48 h from 148 normotensive men and women to compute and compare time-specified tolerance and prediction intervals for blood pressure. Once the threshold, given by the upper limit of the tolerance interval, was available, the hyperbaric index, as a measure of blood pressure excess, could be calculated by numerical integration as the total area of any given patient     

Pattern of leukocytes in the blood of healthy African neonates

Serial leukocyte counts were performed on 107 full-term, 40 preterm and 35 postterm African neonates during the first 4 weeks of life. In addition, WBC differential counts were done on 85 of these neonates, selected randomly. Both the absolute and relative amounts of each cell type were determined. The main features of leukocyte counts during the neonatal period were: a mean leukocyte count of 12,580 cells/mm3 (range 3,500-20,500) on day 1, with no statistical difference observed between any two of the three groups studied; a decline in mean leukocyte count by day 7 which remained stable throughout the neonatal period, and a neutrophil count of 5,670 cells/mm3 (range 980-12,900) on day 1. This figure is much lower, both in relative and absolute numbers, than that reported for babies in Europe and North America. Lastly, the lymphocyte count was consistently higher than in comparable reports from Europe and North America. The constant leukocyte count, particularly that of neutrophils, may be of importance in detecting infected African neonates.     

Distribution of 24-h ambulatory blood pressure in children: normalized reference values and role of body dimensions

BACKGROUND: Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is an essential tool in the diagnosis and therapeutic monitoring of arterial hypertension in children. The statistical use of pediatric ABPM reference values has been compromised by the non-Gaussian distribution of 24-h blood pressure (BP) in children. OBJECTIVE: To develop distribution-adjusted pediatric ABPM reference tables. METHODS: From cross-sectional ABPM data obtained in 949 healthy children and adolescents aged 5-20 years, a set of reference tables was developed for 24-h, daytime and night-time mean values of systolic, diastolic, mean arterial BP and heart rate, utilizing the LMS method to account for the variably skewed distribution of ABPM data. Age- and gender-specific estimates of the distribution median (M), coefficient of variation (S) and degree of skewness (L) were obtained by a maximum-likelihood curve-fitting technique. The estimates of, and can be used to normalize ABPM data to gender and age or height. RESULTS: Re-application of the established, and values in the reference population confirmed appropriate normalization of ABPM values. Height standard deviation scores (SDS), body mass index (BMI) SDS and heart rate SDS were independent positive predictors of 24-h systolic BP SDS. Diastolic 24-h mean BP SDS showed a weak correlation with BMI SDS only. CONCLUSIONS: The use of LMS reference tables permits calculation of appropriate SDS values for ABPM in children. Whereas systolic 24-h BP is independently correlated with age, relative height and obesity, diastolic values are almost independent of age and relative height, and weakly associated with relative obesity.     

Calculated mean arterial blood pressure in critically ill neonates

Summary Mean arterial pressure (MAP) is the area under the pressure wave form averaged over the cardiac cycle. A widely used rule of thumb to estimate MAP of peripheral arterial pressure waves in adults is adding one-third of the pulse pressure (PP) to diastolic arterial pressure (DAP). However, radial artery pressure waves in newborns differ from those in adults and resemble proximal aortic pressure waves, so that the above-mentioned calculation of MAP may not be correct. The present study was set up to obtain an arithmetical approximation to derive MAP from blood pressure waves measured in the radial artery of the neonate. We accurately recorded about 300 invasively obtained blood pressure curves in the radial artery of 10 neonates admitted for intensive care. We found that MAP in the radial artery in these neonates can be well approximated by adding 46.6% PP to DAP (range 43.0–50.1%). We suggest that the rule of thumb to derive MAP from radial artery waves in the neonate to be approximately the average of systolic and diastolic pressure, as opposed to adding one-third of the pulse pressure to the diastolic value in the adult.Abbreviations ABP Arterial blood pressure - SAP Systolic arterial pressure - DAP Diastolic arterial pressure - MAP Mean arterial pressure - PP Pulse pressure - MAP% (MAP-DAP)/(SAP-DAP)×100% (i.e., level of the MAP in the wave, expressed in % PP) - PDA Patent ductus arteriosus - IRDS Idiopathic respiratory distress syndrome     

Influence of repeated measurement on one occasion, on successive days, and on workdays on home blood pressure values

Few reports provide clear guidelines on how home blood pressure (HBP) should be measured in practice. In this study, we evaluated the influence of repeated HBP measurements on one occasion, and the difference between the 1st and 2nd day and between workdays and nonworkdays. The subjects (468 male, 232 female; mean age 41 years) were recruited from one company. HBP was measured with a semiautomatic device (Omron HEM-759P). Subjects were instructed to perform triplicate morning (m) and evening (e) measurements on 7 consecutive days. HBP tended to decrease during repeated measurements: systolic blood pressure (SBP) was significantly higher the 1st time than the 2nd time and 3rd time. There was no difference in diastolic blood pressure (DBP) between the 1st and 2nd time, but the value the 3rd time was significantly lower than the 1st and 2nd time. Both mHBP and eHBP on the 1st day were significantly higher than those on the 2nd day. mHBP was higher on the 1st workday than on nonworkdays, but the difference was less than 1 mmHg and there was no significant difference. Since there were significant differences in HBP during repeated measurements and between the 1st and 2nd day, which value to adopt as HBP needs to be discussed. Whether HBP was measured on a workday or a nonworkday seemed to have little influence on the HBP values obtained.     

高龄老年人24小时动态血压正常参考值及昼夜节律

目的 建立80岁以上老年人的动态血压正常值数据库,以指导老年高血压病的预防和诊治.方法 按照中华医学会老年医学分会健康老年人标准,共96人入选,80～89岁组共50人,其中男35人,女15人;60～69岁作为对照组共46人,其中男31人,女15人.采用美国太空公司生产的无创性携带式动态血压监测仪,型号90217型,白天(600～2300)隔20 min、夜间(2300～600)隔60 min自动充气测压.参数包括24 h平均收缩压(24 hSBP)与舒张压(24 hDBP),白昼(6 am～10 pm)平均收缩压(dSBP)与舒张压(dDBP),夜间(10 pm～6 am)平均收缩压(nSBP)与舒张压(nDBP).结果 80～89岁组与60～69岁组相比,其24 hSBP、dSBP及nSBP之间存在显著差异(P＜0.05),80～89岁组明显大于60～69岁组,24 h动态血压正常参考值为(118±8/72±7)mmHg(1 mmHg=0.133 kPa).结论 高龄老年人24 h动态血压正常值随着年龄的增长有明显改变,尤以收缩压明显,在临床工作中应引起注意.     

CD4+ T lymphocyte reference values of immunocompetent subjects in an African university

CD4(+) T cells play critical roles in the immune system and, being primary targets of HIV infection, they are used to measure disease progression and response to combination antiretroviral therapy (cART), alongside other parameters, in HIV/AIDS patients. The aim of this study was to determine the reference values of CD4(+) T cells in a student population that was HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) negative. After ethical clearance and informed consent, 500 subjects (mean age = 26 years) were recruited, of whom 56 (11.2%) had HIV, HBV or HCV and were excluded. Blood samples were collected from the remaining 444 subjects into vacutainer tubes and analysed using the BD FACScount cytometer according to the manufacturer's instructions. Of the 444 subjects, 266 (59.9%) were male and 178 (40.1%) were female. The mean (± standard deviation) CD4(+) T cell count was 987 cells/μL (± 336). The mean counts among males and females were 957 cells/μL (± 306) and 991 cells/μL (± 340), respectively. Values of CD4(+) T cells ranged from 651 cells/μL to 1705 cells/μL. Subjects with higher CD4(+) T Cells were more likely to be female than male. There was no direct correlation between CD4(+) T cell values and age of the participants. Our findings offer the first insight into the CD4(+) T cell reference values of a Nigerian student population and provide useful data that will guide future cART decisions and other immune-based therapies.     

Standardization of blood specimen collection procedure for reference values*

This document has been prepared by an ICSH Task Force as a proposed ICSH Standard for Blood Specimen Collection for Reference Values. The procedures described are a model for standardization of blood specimen collection either for people confined to bed, or for those who are ambulant; they are intended for obtaining reference values using the principles described in the ICSH paper on the Theory of Reference Values (Clin. lab. Haemat. 3 , 369–373, 1981). The document is based on recommendations by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology as published in Scand. J. clin. lab. Invest. ( 35 , Suppl. 144, 39–43, 1975); it has been prepared in collaboration with the Panel on the Theory of Reference Values of the Scientific Committee of the International Federation of Clinical Chemistry (IFCC). The responsible authorities of ICSH and IFCC have proposed that it should be the basis for joint recommendations by both organizations.     

Factors influencing acute blood pressure values in stroke subtypes

The aim of this prospective observational study was to determine the association of acute blood pressure values with independent factors (demographic, clinical characteristics, early complications) in stroke subgroups of different aetiology. We evaluated data of 346 first-ever acute (<24 h) stroke patients treated in our stroke unit. Casual and 24-h blood pressure (BP) values were measured. Stroke risk factors and stroke severity on admission were documented. Strokes were divided into subgroups of different aetiopathogenic mechanism. Patients were imaged with CT-scan on admission and 5 days later to determine the presence of brain oedema and haemorrhagic transformation. The relationship of different factors to 24-h BP values (24-h BP) was evaluated separately in each stroke subgroup. In large artery atherosclerotic stroke (n=59), history of hypertension and stroke severity correlated with higher 24-h BP respectively. In cardioembolic stroke (n=87), history of hypertension, stroke severity, haemorrhagic transformation and brain oedema were associated with higher 24-h BP, while heart failure with lower 24-h BP. History of hypertension and coronary artery disease was related to higher and lower 24-h BP, respectively, in lacunar stroke (n=75). In patients with infarct of undetermined (n=57) cause 24-h BP were mainly influenced by stroke severity and history of hypertension. An independent association between higher 24-h BP and history of hypertension and cerebral oedema was documented in intracerebral haemorrhage (n=68). In conclusion, different factors influence acute BP values in stroke subtypes of different aetiology. If the clinical significance of these observations is verified, a differentiated approach in acute BP management based on stroke aetiology may be considered.     

Increased sodium concentrations in drinking water increase blood pressure in neonates

BACKGROUND : In a previous study, we found that increased sodium concentrations in the drinking water led to an increase in mean arterial pressure (MAP) and systolic blood pressure (SBP) in fourth- and fifth-grade school children. Milk powder formulae have a low content of sodium, almost identical to that of breast milk. However, the final sodium concentration in the milk formula depends upon the concentration of sodium in the diluting water, which varies remarkably. OBJECTIVE : To evaluate changes in blood pressure during the first 2 months of life in neonates receiving low-sodium mineral water (LSMW), high-sodium tap water (HSTW), or breast milk. DESIGN : A randomized, prospective study in a teaching hospital. METHODS : Fifty-eight Jewish term infants maintained on milk formula were randomly assigned to two groups. Group 1 consisted of 25 infants whose formula was diluted with LSMW (Eden Spring Mineral Water) having a sodium concentration of 32 mg/l (1.4 mmol/l). Group 2 contained 33 infants whose formula was diluted with HSTW having a sodium concentration of 196 mg/l (8.5 mmol/l). Fifteen breastfed babies served as the control group (group 3). Weekly weight, height, head circumference, heart rate, and systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were recorded for each infant for 8 consecutive weeks after birth. After 8 weeks, group 1 reverted to a diet similar to that of group 2. At 6 months of age (week 24), a follow-up blood pressure measurement was performed in 11, 20 and seven infants in groups 1, 2 and 3, respectively. Blood pressure was measured during sleep. Urinary sodium : creatinine ratio was determined monthly during the initial 2 months. RESULTS : Increases in weight and height were equal in all groups. Heart rate did not differ between groups during the entire study period. From the age of 6 weeks until week 8, MAP, SBP and DBP were found to be significantly greater in the group 2 (HSTW). In parallel, the urinary sodium : creatinine ratio was significantly greater in this group. At week 24, blood pressure values in group 1 increased towards those of group 2. CONCLUSIONS : Diluting milk formula with tap water containing a high concentration of sodium will result in the infant being fed a high-salt diet. To equilibrate with breast milk, formula should be diluted with low-salt water. Blood pressure in the neonate is increased by a high sodium intake via drinking water.     

Comparison of self-reported home blood pressure measurements with automatically stored values and ambulatory blood pressure

Aims: To evaluate accuracy of patient-reported home blood pressure measurements (HBPM) when compared to real HBPM and their agreement with 12-h daytime ambulatory blood pressure monitoring (ABPM). Major findings: Self-reported HBPM were compared to stored values of a fully automated, oscillometric blood pressure monitor with integrated memory device and 12-h daytime ambulatory monitoring in 54 patients. In most patients (n