Oscillometric Blood Pressure Standards for Children

We previously reported blood pressure (BP) readings obtained by the Dinamap (DIN) (Model 8100) were 10 mmHg higher than those obtained by auscultatory methods and thus were not interchangeable. DIN BP data on 7208 schoolchildren ages 5 to 17 were analyzed to generate normative DIN BP standards and to examine the rational for presenting BP standards according to age and height percentiles. Three BP measurements were taken in the sitting position using a BP cuff width 40% to 50% of the circumference of the arm. Boys’ systolic pressures (SP) were significantly (p < 0.05) greater (up to 11 mmHg) than those of the girls in subjects age 13 to 17 years. SP levels were most closely correlated with weight (r = 0.595), followed by height (r = 0.560) and age (r = 0.518). When BP levels were adjusted for age and weight, the correlation coefficient of DIN SP with height was negligible (r = 0.026 for boys; r = 0.085 for girls), whereas when adjusted for age and height, the correlation of SP with weight remained high (r = 0.303 for boys; r = 0.216 for girls), indicating that height is not an important independent predictor of BP levels. In conclusion, Dinamap-specific BP standards presented in this report are the only standards that have been generated according to the current BP guidelines recommended by national committees. We found no rational for presenting BP standards according to age and height percentiles.     

Comparison of auscultatory and oscillometric blood pressures

OBJECTIVE: To study the differences in blood pressure readings between the auscultatory and oscillometric (Dinamap model 8100; Critikon, Tampa, Fla) methods. DESIGN: Survey of 2 blood pressure instruments. SETTING: Public schools. PARTICIPANTS: Seven thousand two hundred eight schoolchildren aged 5 through 17 years. MAIN OUTCOME MEASURE: Blood pressure levels. RESULTS: For all children combined, Dinamap systolic pressure readings were 10 mm Hg higher (95% confidence interval, -4 to 24 mm Hg) than the auscultatory systolic pressure readings. Dinamap diastolic pressure readings were 5 mm Hg higher (95% confidence interval, -14 to 23 mm Hg) than the auscultatory Korotkoff phase V diastolic pressure readings. CONCLUSION: These findings preclude the interchange of readings by the 2 methods. Caution must be exercised in the diagnosis of hypertension when an automated device is used.     

Differences in blood pressure levels obtained by auscultatory and oscillometric methods

Levels of blood pressure measured by the conventional auscultatory method were compared with those measured by the Dinamap Monitor (Dinamap Monitor 1846 SX, Critikon Inc, Tampa, Fla), an oscillometric device. Triplicate measurements were obtained by the two methods 10 to 15 minutes apart in 381 seated fifth-grade children, ages 10 to 13 years. The width of the air bladder of the blood pressure cuff was selected to be 40% to 50% of the circumference of the upper arm. The mean systolic and diastolic pressures (at the fourth phase of Korotkoff sounds) by the auscultatory method were 6.4 mm Hg lower and 8.7 mm Hg higher than the oscillometric systolic and diastolic blood pressures, respectively. The findings of this study suggest that published normative levels of auscultatory blood pressure may be inappropriate as a standard when blood pressure measurement is obtained by the Dinamap Monitor. Until a new set of normative Dinamap blood pressure levels becomes available, one should use equations (A = 12.8 + 0.82D for systolic, and A = 34.3 + 0.54D for diastolic blood pressures at the fourth phase of Korotkoff sounds, where A is auscultatory blood pressure and D is Dinamap blood pressure) to predict auscultatory blood pressures before Dinamap blood pressures are compared with normative auscultatory blood pressure levels.     

Normative arm and calf blood pressure values in the newborn

Indirect BP measurement was obtained in the right upper arm in 219 healthy newborn infants with the Dinamap monitor and was compared with values obtained from the calf to establish normative BP values and to help establish a diagnosis of hypertension and coarctation of the aorta in the newborn. There were 174 Mexican-Americans (79.5%), 33 whites (15.0%), and 12 blacks (5.5%). The width of the BP cuff was selected to be 0.4 to 0.5 times the circumference of the extremities. Three supine position readings of BPs and heart rate were obtained from each site and were averaged for statistical analyses. Mean arm BP values (+/- SD) of the neonate less than 36 hours of age were 62.6 +/- 6.9/38.9 +/- 5.7 mm Hg (48.0 +/- 6.2 mm Hg). Neonates older than 36 hours had slightly but significantly (P less than .05) greater values (4 to 6 mm Hg) than did infants younger than 36 hours of age. Active neonates had values 6 to 10 mm Hg greater than quiet neonates (P less than .05). BP values in the calf obtained with the same-sized cuff were almost identical with those obtained from the arm. Differences in consecutively obtained arm and calf BPs (arm values minus calf values) were 1.1 +/- 7.7 mm Hg systolic, -0.01 +/- 6.2 mm Hg diastolic, and 0.9 +/- 6.9 mm Hg mean pressures. Mean heart rate (+/- SD) of neonates less than 36 hours of age was 129.4 +/- 13.2 beats per minute and that of neonates older than 36 hours of age was 139.4 +/- 14.1 beats per minute.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blood pressure measurement in preschool children: The Hisayama study

Objective: To establish the blood pressure (BP) measurement protocol for Japanese preschool children, systolic BP (K1) and diastolic BP (K4, K5) were measured along with anthropometric values.
Methodology: Commercially available mercury sphygmomanometers were used. In the first group of children (group A), BP was measured in 79 boys and 85 girls using a cuff 9 cm wide and 23 cm long. In the second group (group B), the length and circumference of the upper right arm of 147 boys and 139 girls were measured to select cuffs appropriate for their sizes. Blood pressure measurements were performed twice on the right arm of the children in the seated position at a mean interval of 5 min.
Results: There were no significant differences in the anthropometric values (height, bodyweight, body mass index [BMI], length and circumference of the upper arm) between groups A and B. The BP values at K1, K4 and K5 in the first measurement of group B were 91 ± 9, 54 ± 8, and 48 ± 10 mmHg (boys) and 90 ± 9, 54 ± 8, and 48 ± 12 mmHg (girls), respectively. There were no significant differences between the first and second measurements in both groups, however, there were significant differences in the first and second measurements of K4 between groups A and B. Multiple regression analysis by the stepwise method revealed a strong correlation between K1 and the length of the upper arm in the boys and the bodyweight in the girls: between K4 and the bodyweight in the boys and the BMI in the girls, and between K5 and the height in the boys and the upper arm circumference in the girls.
Conclusions: From these results it would appear that a single measurement is sufficient under appropriate measurement conditions such as rest before measurement and the choice of the cuff size according to the upper arm circumference, and that BP is closely correlated with the anthropometric values in preschool children.     

Longitudinal data of blood pressure and pulse frequency during childhood (author's transl)

From 1968-1980 the development of blood pressure and pulse frequency in 221 healthy boys and 230 healthy girls aged 2-16 years was studied longitudinally. An automatic blood pressure device recording on a paper tape pulse frequence as well was used. Systolic readings are taken at the first appearance, diastolic readings at the disappearance of the Korotkoff sounds. A steady increase of the systolic, and to a lesser extent, of the diastolic pressure can be observed. Boys have a more pronouned increase of systolic pressure than girls. From year 2-16 the 50th percentile increases from 90 mm Hg to 128 mm Hg in boys and from 92 mmHg to 116 mm Hg in girls. The 50th percentile of diastolic pressure increases from 61 to 66 mm Hg in boys and 65 to 71 mm Hg in girls. Pulse frequency of boys is comparable to that of girls. The 50th percentile decreases from 100 to 75 beats. Increasing age is paralleled by decreasing pulse frequency.     

Non-invasive oscillometric measurement of systolic,mean and diastolic blood pressure in infants with congenital heart defects after operation. A comparison with direct blood pressure measurements

The accuracy of indirect oscillometric blood pressure measurements has been evaluated in 32 infants up to 11 months of age undergoing heart surgery. In a number of 1029 simultaneous measurements the indirect blood pressure was compared with the direct value obtained from a radial artery catheter. Cuffs of different sizes were applied. The main results were as follows: (1) Regarding the ratio of cuff width to arm circumference, the best correlation between oscillometric and direct blood pressure measurements was obtained with a ratio of 0.38–0.41. (2) The value of indirect blood pressure measurements depends on the absolute height of the blood pressure. In low blood pressure there is a tendency to underestimate and in high blood pressure there is a tendency to overestimate by the oscillometric blood pressure measurement.By applying an appropriate cuff size and by using our diagrams it should be possible to derive a direct value for the blood pressure on the basis of indirect oscillometric blood pressure measurements.Abbreviations BP blood pressure - BPM blood pressure measurements - CW/ArmC cuff width to arm circumference ratio - DAP diastolic arterial pressure - MAP mean arterial pressure - SAP systolic arterial pressure - ME mean error - SD standard deviation Research fellow supported by the A. v. Humboldt Stiftung     

Paediatric hypertension – evaluation and management

Hypertension (HT) is an increasing problem in children, mainly because of the increasing prevalence of obesity. Unlike adults, the diagnosis of HT in children is based on the age, sex and height of the child. The overall prevalence is thought to be 1–5%. Measurement of blood pressure can be challenging in infants and young children. BP must be measured in the upper arm using an appropriate sized cuff. It is important to confirm automated oscillometric readings by a manual auscultatory method or by using a Doppler. The latter is particularly useful in infants. There is an increasing role for ambulatory BP monitoring in the diagnosis and also assessment of BP control.The aetiology of HT varies depending upon the age of the child, with renal parenchymal pathology being the predominant pathology in young children while obesity is the main cause in older children. The baseline investigations in all children include electrolytes, creatinine, urine dipstick and an ultrasound scan of the renal tract. Therapeutic lifestyle measures would be the initial treatment of choice for all patients with stage I hypertension. Pharmacotherapy is indicated if these measures fail or if there is stage II HT or evidence of target organ damage.     

Arterial blood pressure in the very low birthweight neonate. Evaluation of an automatic oscillometric technique

The noninvasive oscillometric technique of arterial blood pressure determination was evaluated in fifteen very low birth weight neonates (less than 1,400 g). Measurement of invasive umbilical artery catheter pressure was used as a reference standard. By using a cuff width to arm circumference ratio of 0.33-0.42, mean blood pressure was overestimated by 6.2 (7.2) mmHg (mean and 1 SD), p less than 0.001. More accurate mean blood pressure measurements were recorded with a cuff width to arm circumference ratio of 0.44-0.55. Measurements of systolic and diastolic blood pressure showed similar results.     

Ambulatory blood pressure monitoring.

Ambulatory blood pressure monitoring (ABPM) in adults is proving to be useful. The aim of this study was to determine if ABPM is accurate in the lower blood pressure range encountered in children and, equally important, whether it is acceptable to children. Thirty one children, between the ages of 6 and 18 years, were assessed using an ambulatory blood pressure monitor that uses an auscultatory method. Blood pressure was measured in the contralateral arm with a mercury sphygmomanometer and an oscillometric device at the beginning and end of the study for comparison. Over a blood pressure range of 90-130 mm Hg systolic and 40-80 mm Hg diastolic, a close agreement was found with the sphygmomanometer; the limits of agreement (+/- 2 SD) were 11.6 mm Hg for systolic blood pressure and 13.6 mm Hg for diastolic blood pressure. The bias was less than 1.0 mm Hg. The ambulatory device was worn by all patients for at least 16 hours with an average of 52 recordings per patient. The majority found the device comfortable to wear and were not woken from sleep.     

Ambulatory blood pressure monitoring

Ambulatory blood pressure monitoring (ABPM) in adults is proving to be useful. The aim of this study was to determine if ABPM is accurate in the lower blood pressure range encountered in children and, equally important, whether it is acceptable to children. Thirty one children, between the ages of 6 and 18 years, were assessed using an ambulatory blood pressure monitor that uses an auscultatory method. Blood pressure was measured in the contralateral arm with a mercury sphygmomanometer and an oscillometric device at the beginning and end of the study for comparison. Over a blood pressure range of 90-130 mm Hg systolic and 40-80 mm Hg diastolic, a close agreement was found with the sphygmomanometer; the limits of agreement (+/- 2 SD) were 11.6 mm Hg for systolic blood pressure and 13.6 mm Hg for diastolic blood pressure. The bias was less than 1.0 mm Hg. The ambulatory device was worn by all patients for at least 16 hours with an average of 52 recordings per patient. The majority found the device comfortable to wear and were not woken from sleep.     

Ambulatory blood pressure in schoolchildren.

OBJECTIVE: To define the range and variability of ambulatory blood pressure in normal schoolchildren. DESIGN: Prospective study. METHODS: Resting blood pressure of 1121 schoolchildren from Newcastle upon Tyne was recorded. An ambulatory blood pressure device, which uses both auscultatory (Korotkoff) and oscillometric methods of blood pressure measurement, was then put in place for 24 hours. RESULTS: The day was divided into three time periods: school, home, and night time. Normal centiles for blood pressure for each of these time periods were obtained and many daytime readings were outside reported normal resting levels. The normal variation of blood pressure was quantified by comparing each of these time periods with the resting readings. Resting systolic blood pressure did not predict 24 hour mean systolic blood pressure. CONCLUSIONS: The availability of normal ambulatory blood pressure data on the level and variation of blood pressure in children may facilitate the early identification of hypertension in this age group.     

Arterial Blood Pressure in the Very Low Birthweight Neonate

ABSTRACT. The noninvasive oscillometric technique of arterial blood pressure determination was evaluated in fifteen very low birth weight neonates (<1400 g). Measurement of invasive umbilical artery catheter pressure was used as a reference standard. By using a cuff width to arm circumference ratio of 0.33–0.42, mean blood pressure was overestimated by 6.2 (7.2) mmHg (mean and 1 SD), p <0.001. More accurate mean blood pressure measurements were recorded with a cuff width to arm circumference ratio of 0.44–0.55. Measurements of systolic and diastolic blood pressure showed similar results.     

新疆伊犁地区2438例哈萨克族儿童血压现况分析

目的：了解新疆伊犁地区哈萨克族儿童血压水平和高血压的发生状况及影响因素。方法：2009年5~6月采用随机整群抽样方法,抽取新疆伊犁地区哈萨克族学龄儿童2438例,进行身高、体重、腰围、臀围、皮褶厚度、血压测量,并计算体质指数（BMI）。结果：2438名儿童收缩压（SBP）平均水平为94±13 mm Hg,舒张压（DBP）平均水平为60±9 mm Hg,低于国内同年龄段汉族平均水平;检出高血压儿童138名,患病率5.66%（138/2438）,其中男童患病率4.38% （54/1232）,女童患病率6.97%（84/1206）,女童患病率高于男童（P<0.05）;血压及高血压患病率与BMI、腰围、臀围、皮褶厚度、性别、年龄均呈正相关。结论新疆伊犁地区哈萨克族儿童血压平均水平较国内儿童低;女童高血压患病率高于男童;肥胖与哈萨克族儿童高血压患病率密切相关。     

Comparison between oscillometric and invasive blood pressure measurements in critically ill premature infants

Aim: Blood pressure (BP) measurement techniques in neonates generally involve noninvasive measurements with a cuff (oscillometric) or invasive measurements through an arterial catheter. The aim of this study was to determine the reliability of the noninvasive oscillometric method in critically ill preterm infants when results were compared with the invasive technique. Method: Twenty‐seven premature infants with a mean birth weight of 1138 ± 552 g were enrolled in the prospective study. Invasive and noninvasive mean arterial pressure (MAP) levels were recorded simultaneously at each measurement in all patients. Low or lower range mean invasive MAP values (MAP ≤30) were evaluated separately as we aimed to assess the value of noninvasive measurements in hypotensive sick premature infants. Results: Totally, 431 paired BP measurements were taken during the first week of life. There was no statistically significant difference between invasive and noninvasive readings. However, noninvasive measurements were found significantly higher compared with invasive measurements in the presence of hypotension (p < 0.05). Conclusion: This study showed good agreement between oscillometric and invasive readings in critically ill premature infants, and further, comparable mean MAP values were found with the two methods. However, the accuracy of the oscillometric BP measurement technique fails in preterm infants with BP within the lower limits.     

Blood pressure levels in south Indian adolescents.

The present study was undertaken to develop normative data for the blood pressure (BP) levels in adolescent boys and girls aged 10-17 years residing the rural and urban areas of North Arcot Ambedkar District, Tamil Nadu State. Blood pressures were evaluated as part of an ongoing study on growth and development in adolescents. A total of 7028 BP measurements collected cross-sectionally were subjected to statistical analysis. The mean systolic (SBP) and diastolic (DBP) blood pressure levels were elevated in rural children as compared to that in urban children of respective sexes during 10 and 15 years of age. The mean BP levels were higher in both the rural and urban girls as compared to their male counterparts till the age of 15, after which the trend was reversed. While the mean SBP and DBP levels for rural children of either sex were stable over the age range considered, those for urban children exhibited consistent increase with age. In urban boys, the yearly mean increments in SBP and DBP were 2.5 mm Hg and 2.0 mm Hg and that in urban girls 2.4 mm Hg and 1.7 mm Hg, respectively. It is suggested that perhaps stress factors are responsible for the elevated mean BP levels among the rural adolescents as they are generally engaged in activities that exert considerable physical and psychological stress.     

Prediction of arterial blood pressure in the premature neonate using the oscillometric method

The noninvasive oscillometric measurement of blood pressure (BP) in preterm neonates has become a common practice in intensive care nurseries. The method has gained acceptance primarily through its correlation with direct arterial measurement. In this study, the oscillometric method (using Dinamap 1846) was compared with direct intra-arterial BP monitoring in 15 preterm infants. The 95% prediction intervals for individual oscillometric measurements were wide, ranging from 17 mm Hg for the mean BP to 20 mm Hg for the systolic and diastolic BP. The oscillometric method also underestimated intra-arterial systolic and mean BP and overestimated diastolic BP. Caution must be used when oscillometrically measuring BP in premature neonates.     

Effect of central corneal thickness and radius of the corneal curvature on intraocular pressure measured with the Tono-Pen and noncontact tonometer in healthy schoolchildren

PURPOSE: To determine the effect of central corneal thickness and radius of the corneal curvature on intraocular pressure (IOP) measurements using the Tono-Pen and a noncontact tonometer in healthy Turkish schoolchildren. SUBJECTS AND METHODS: IOP was measured with the Tono-Pen and a noncontact tonometer in 602 eyes of 602 healthy schoolchildren with a mean age of 10.1 +/- 1.6 years. Central corneal thickness was measured using an ultrasonic pachymeter after all IOP determinations had been made. The effect of central corneal thickness, radius of the corneal curvature, and sex on measured IOP was explored by linear regression analysis. RESULTS: The mean central corneal thickness was found to be 564.92 +/- 32 microm. The mean IOP readings were 17.9 +/- 2 mm Hg using the Tono-Pen, and 16.7 +/- 2 mm Hg using a noncontact tonometer. The Tono-Pen measured IOP values slightly greater than the noncontact tonometer (P < .0001). A significant association between measured IOP and central corneal thickness was found with each device. The IOP increased 2.1 and 4.2 mm Hg with every 100-microm increase in central corneal thickness for the Tono-Pen and the noncontact tonometer, respectively. The dependence of IOP on central corneal thickness did not differ between boys and girls. There was a significant association between the Tono-Pen and noncontact tonometer differences and central corneal thickness; the noncontact tonometer tended to overestimate IOP in eyes with thicker corneas. CONCLUSIONS: The Tono-Pen readings appeared to be less affected by corneal thickness than those of the noncontact tonometer. The corneal radius of curvature had no significant effect on measured IOP with each device. Because the Tono-Pen was relatively easy to use and less affected by corneal thickness, it may be an alternative method for measuring IOP in children.     

北京地区儿童及青少年血压分布特征

目的了解北京地区儿童青少年血压的现况。方法按分层整群随机抽样法在北京市4个城区和3个郊区县的3—18岁儿童和青少年中,用“美国高血压教育项目工作组”和“中国高血压防治指南”推荐的测量方法进行收缩压（SBP）和舒张压（DBP）测量。记录、整理、分析血压测量的结果。结果北京地区3—18岁儿童青少年血压调查的有效数据人数20780人,城区10582人（50．9％）,郊县10198人（49．1％）;男10398人（50．0％）,女10382人（50．0％）。男童血压高于女童[SBP：（106±12）mmHgVS（101±11）mmHg,u=27．14,P〈0．01;DBP：（67±9）mmHgvs（65±8）mmHg,u=14．14,P〈0．01]（1mmHg=0．133kPa）。男女童血压均随年龄增长有逐渐增高的趋势,且SBP上升幅度较DBP高。城区儿童SBP和DBP的平均水平低于郊县儿童[SBP：（103±12）mmHgVS（104±12）mmHg,u=2．55,P〈O．05;DBP：（66±8）mmHgVS（67±9）mmHg,u=6．73,P〈0．01]。血压与年龄、身高、体重及体块指数（BMI）均有显著的正相关（P〈0．001）,收缩压与各变量的相关程度均较舒张压高。依据1987年北京市6—18岁儿童青少年性别年龄别血压标准,本次调查6～18岁儿童青少年高血压检出率为8．1％。结论获得了北京地区儿童青少年血压的分布特征;血压值与儿童的性别、年龄、身高、体重和BMI相关。     

Growth of arm circumference and triceps skinfold of Malay children from birth to six years of age

126 Malaysian children, 65 boys and 61 girls from higher income families were followed-up regularly from birth to six years of age in the University Hospital, Kuala Lumpur. The study shows that for boys and girls, there is a progressive increase in the left mid-upper arm circumference from birth to six years of age. However the rate of growth is not even, being most rapid during the first four month of infancy, then rapidly decreases during the middle third of infancy and thereafter it decreases slowly and by the second year of life, there is hardly any increase in the arm circumference. The left triceps skinfold thickness curves for boys and girls rise rapidly after birth to reach a peak at about three to five months before commencing to decline and then flatten off from the second year of life. The study also shows that on the whole, boys have slightly bigger arm circumference than girls during the first two years of life. From two years of age, girls on the average have more fat than boys. However this difference is statistically not significant at the ages tested. This paper also presents the left mid-upper arm circumference and left triceps skinfold percentile charts of Malaysian boys and girls from birth to six years of age.