Systemic hypertension is one of the commonest cardiovascular diseases in adults. Over the past decade, several advances have been made in evaluating the state of blood pressure in children. Paediatric hypertension, nonetheless, remains poorly recognised. Essential hypertension is the most common form of hypertension in adults, but it is becoming increasingly clear that the origin of this condition is in childhood. The prevalence of essential hypertension during childhood is increasing, in keeping with the increasing prevalence of obesity. Secondary hypertension is clinically much more important in children, and is commonly caused by renal disease. Early detection and control not only reduce the general morbidity of hypertension, but also protect the function of the already damaged kidney. Fortunately, recent pharmacological advances enable the blood pressure to be controlled in all patients, with a minimum of undesirable side effects. Consequently, the management of hypertension is particularly rewarding for the practising paediatrician.
EVALUATION OF BLOOD PRESSURE: MEASUREMENT, NORMAL VALUES, AND IMPORTANT INFLUENCES
Measurement of Systemic Blood Pressure
In this section, we discuss issues related to the measurement of blood pressure in the clinic or office, along with 24-hour ambulatory monitoring. Measurement of blood pressure in children is usually first performed at the time of their first presentation to a paediatric department, or as part of their first school physical examination. It is often omitted. Common reasons cited by clinicians include the practical difficulties in making measurements in infants and young children, changing normative limits throughout childhood, and the belief that hypertension is primarily an adult disease. There are several aspects to measurement that need consideration. These include the type of measuring machine, the type of cuff and bladder, the technique of measurement, and variables relating to the patient, the observer, and the environment in which the measurements are made.
Cuff and Bladder
The cuff is the inelastic covering that encases an inflatable rubber bladder. The cuff is usually made of cloth, using semisynthetic or any other material that will reliably and evenly transmit pressure over the artery once the bladder is inflated. A combination that allows removal of the bladder from the cuff so that the cuff can be washed at regular intervals is probably more desirable. 1
The inflatable bladder, rather than the cuff, needs to be of the correct size. Failure to select the correct size of bladder remains the most common error in the measurement of blood pressure. Miscuffing refers to the inaccuracy introduced as a result of using a bladder that is too small and narrow, or too long relative to the circumference of the upper arm. It is advisable to choose a size of cuff in relation to the circumference of the arm as opposed to its length. Although debated, most researchers in this area agree that the width for children should be about two-fifths of the circumference of the upper arm. 2 This is because measurements made using circumference rather than length as the yardstick correlate best with intra-arterial readings. In both adults and children, use of cuffs which are too small in length, or too narrow in width, will overestimate the pressures measured by errors ranging from 3 over 2 to 12 over 8 mm Hg, with even greater ranges of error in obese individuals. 3 This is sometimes referred to as cuff hypertension. Too large a cuff is increasingly being recognised as a cause of underestimation of pressure in both adults and children. 4–7 Length of the bladder is much more important in children than adults, and also leads to overestimation of the measured pressure. 8
The suggested solution to the problem of the size of the cuff is to have a range of sizes of bladder available. In the United Kingdom, cuffs and bladders measuring 4 cm in width and 13 cm in length, and then 8 by 18 cm, 12 by 18 cm, 12 by 26 cm, and 12 by 40 cm are available. These usually suffice for arms of all sizes across the paediatric age range, including lean and obese children. Other national societies recommend different sizes. 5 The bladder should be centred over the brachial artery, and should encircle from four-fifths to all of the upper arm. 5,8 In practice, the widest cuff should be used to permit auscultation of the antecubital fossa. The size used should be recorded so that sequential measurements can be compared in the same patient.
Instruments
The mercury sphygmomanometer combined with an inflated cuff and auscultation remains the gold standard for the measurement of blood pressure in children. Widely accepted centiles for normal pressures through childhood have been developed using such a standard mercury sphygmomanometer instrument. 9 Recently, nonetheless, concerns have emerged regarding the safety of mercury for users in the clinical environment, for technicians who have to service the instrument, and for the environment itself. 10,11
An issue with any method using auscultation is the introduction of the phenomenon of terminal digit preference, and bias of the observer because of knowledge of previous measurements. Any instrument that eliminates or reduces these two is to be welcomed. This initially led to the development of the random-zero sphygmomanometer, which was developed and shown to minimise or eliminate both these items. 12,13 Unfortunately, these devices were shown subsequently significantly to underestimate blood pressure, and were therefore abandoned. 14,15
Automated oscillometric devices have similarly been developed. These improve on the shortcomings of the auscultatory method by eliminating both terminal digit preference and the bias of the observer. They work by the detection of pressure pulses in the cuff. These are generated as a result of the volume pulses of the artery. When blood starts flowing through the artery at the point of systolic pressure, a pressure pulse is generated. As pressure within the deflating cuff is reduced in a stepwise manner, a series of pressure pulses generate the pulse oscillogram. The pulse amplitudes of this oscillogram provide an envelope curve, with the maximal value on this curve equating to the mean arterial pressure. Systolic and diastolic pressures are calculated from preset algorithms in the instrument microchip, and are a function of the mean. The algorithms are specific to the instrument, and are not declared by the manufacturers. 16,17 Although these automated devices are increasingly being used in primary care and paediatric departments, there are some particular concerns that need to be highlighted. The Dinamap devices are the most commonly studied automated oscillometric devices reported in paediatric series. An earlier version of this device, model 1846 SX, had been shown to have superior correlation with intra-arterial measurements. 18 Other studies, however, reported higher mean systolic measurements using models 1846, 8100, and 845 when compared with the random-zero sphygmomanometer and mercury sphygmomanometer. 19,20 Diastolic measurements had been reported to have better agreement. 19 A more recent report using the Dinamap 8100 monitor highlighted the discrepancy between the two methods, with measurements using the device higher by a mean of 10 mm Hg for systolic and 5 mm Hg for diastolic blood pressure. 21 Although normative limits have been proposed using the Dinamap 8100 instrument, caution needs to be proposed before applying these limits in clinical practice. 22 Another particular practical observation with oscillometric devices is the phenomenon of measurements being higher by about 3 to 5 mm Hg on first measurement, despite control of factors involving the patient, the observer, and the environment. 20,23 The second reading has been reported to be more accurate.
Automatically inflated cuffs have recently been introduced. These measure both systolic and diastolic pressures, recording the results at preset intervals by detecting oscillations in the pressure from the cuff. They are especially useful in the care of the critically ill child, saving nursing time and reducing disturbance to the patient. The calibration needs to be checked frequently if the result is to be regarded as accurate, but they are useful in detecting changes. Indeed, they will alarm automatically if preset parameters are exceeded.
Aneroid sphygmomanometers have also gained in popularity in clinical practice because of their portability and their reliance on techniques similar to the standard mercury sphygmomanometer. Because of this, however, they have no influence on the biases existing with the mercury sphygmomanometer. The devices have proven their accuracy when regular 6-month maintenance is in place to service the instruments. 24
The majority of devices in clinical use, nonetheless, have not been evaluated independently for accuracy using the two most widely accepted protocols for validation. 25,26 These protocols have been proposed by the British Hypertension Society and the Association for the Advancement of Medical Instrumentation. Several updates of validation have been published, but the best method of finding up-to-date information is on the nonprofit Web site http://www.dableducational.com . 27
Technique of Measurement
The child should be relaxed and quiet when blood pressure is recorded. Should this not be possible, but readings are made, then the conditions should be recorded. A simple description of the process of measurement to a child at a level appropriate for age will usually lead to a cooperative patient, thus allowing accurate recordings. Measuring pressures in infants who are crying is not useful. The standard position is the sitting position when children are older than 3 years, with the fully exposed arm supported or resting on a table at the level of the heart. 23 An arm higher than the heart will underestimate the pressure, while a lower position will produce overestimations. 28 In younger children and infants, pressure should be routinely measured when the patient is in the supine position. The sphygmomanometer should be placed at the level of the eye of the observer to eliminate error from parallax. The cuff should be inflated about 30 mm Hg above the point at which the radial pulse disappears. In some patients, there will be a silent gap between the systolic and diastolic pressures. Simply inflating the cuff until the sound disappears in such individuals may produce a serious underestimation of systolic pressure. Once inflated, the cuff should be deflated at a rate of 2 to 3 mm Hg per second while auscultating with the stethoscope. The sudden distension of the collapsed artery at the systolic pressure is associated with a clear tapping sound, defined as phase 1 of the Korotkoff sounds. The murmur of turbulent blood flowing through the partially occluded artery is phase 2. Phase 3 is a high-pitched sound produced when the artery, closed during diastole, opens in systole. When the artery no longer closes during diastole, the tapping sounds are low pitched and muffled and quieter. This is phase 4. Phase 5 is when the sounds disappear. This is variable, and may not occur in some children. The fourth phase, however, tends to overestimate the diastolic pressure, while the fifth phase underestimates it. Although the fifth sound is widely accepted as the optimal measurement of diastolic pressure amongst adolescents and adults, there has been considerable debate in the literature concerning its value in children younger than 13 years of age. For these younger children, the fourth sound had generally been preferred, and was recommended by the Task Force Reports on Blood Pressure Control in Children. 29,30 An international committee, nonetheless, recommended the fifth sound, 31,32 and the update of the Task Force Recommendations also advocates using this sound. It is preferred because of its easier identification by observers and the comparability it provides for measuring diastolic pressures across age groups. The two sounds are not equal in most children, and may vary considerably, by up to 10 mm Hg. 33
The measurement of blood pressure in infants, and in some older children, is sometimes difficult because the sounds are inaudible. The old flush technique is unreliable. It has now been superseded by the use of Doppler ultrasound, using an ultrasonic beam to detect motion of the arterial wall when the cuff is deflated. This technique is remarkably reliable for measurement of the systolic pressure, and corresponds to the intra-arterial pressure better than any other method, including auscultation. 34 It is less reliable in the measurement of diastolic pressure, even when machines specifically designed for diastolic pressure are used. 35 All hospital paediatric departments, especially those specializing in paediatric cardiology, should have an ultrasonic machine for measurement of blood pressure. It is particularly useful in determining pressure in the legs in children with suspected aortic coarctation. 34 Recording of the systolic blood pressure by palpation of the radial artery underestimates the pressure by as much 11 mm Hg. 34 The blood pressure measurement should be recorded immediately, without rounding off the measured value to the nearest preferred whole value.
The number of measurements to be obtained for each visit in order for the observer to be assured that the measured pressure is accurate is also important. In practical terms, an observer should attempt to take at least two or three measurements at each visit. The second measurement is a truer reflection of the pressure, the first being least accurate, especially when measured with an automated oscillometric instrument. Measurements over two, and preferably three, visits should be considered to provide a better reflection of a given blood pressure. 9,20
Ambulatory Measurement of Blood Pressure
Ambulatory monitoring using a small, portable, programmable monitor, and performed over a continuous 24-hour period, has become a well-accepted method for the diagnosis of hypertension and assessment of treatment in adults. It is now increasingly gaining recognition for its superior role in the diagnosis and evaluation of blood pressure in children. The monitors typically use an oscillometric technique. They can be programmed to record the blood pressure frequently, for example, every 30 minutes during the day and hourly at night. The readings are stored for later downloading, display and analysis by personal computer. The monitor can be worn on the belt or in the pocket, and the recording is made as the children carry on their normal daytime and night-time activities.
There are some inherent disadvantages of recording a single measurement of blood pressure, since pressure itself is a continuous variable. Additionally, there is the phenomenon of white coat hypertension, especially in children. We discuss this in more detail later. Measures made in the clinic also provide no information of pressures when the patient is asleep. Monitoring over a 24-hour period has several advantages over solitary measurements. It is a more accurate representation, being more physiological and detecting the circadian variation in pressure. Multiple measurements are made in the regular environment, including measurements when the patient is both awake and asleep. Measurements are automatically stored, removing observer error and bias. The technique has been shown to have higher reproducibility than measurements made in the clinic in adults. 36–39 This has also been shown in children, 40–44 although reproducing the nocturnal decline in pressure has not been observed as consistently. 37,44 With improving technology, the instruments themselves have become smaller, and this has resulted in their improved tolerability by children, even in infants and toddlers as young as 2 months of age, 45 although there are no normative limits for this population. As normative standards for ambulatory measurements exist only for children older than 5 years of age, we would not recommend such monitoring in younger children.
Increasing age, and higher mean arterial pressures, have previously been described as factors that improve the rate of success of ambulatory measurements made over 24 hours. 46,47 Our own experience is that monitoring is well tolerated, with more successful measurements achieved when patients are asleep than when awake. This is primarily related to the normal unrestricted daytime activity of the child causing errors in measurement due to movement. 48
Accurate documentation of the waking and sleeping periods is important for correct interpretation of any study made over 24 hours. A number of studies in children have considered measurements only during a fixed waking period, between 08:00 to 20:00, or sleeping, from 24:00 to 06:00, in effect ignoring measurements made over 6 hours during the period of 24 hours. This method has been preferred by some as it improves accuracy in correctly classifying measurements made when the patient is awake and asleep. Our own practice has been to identify correctly the periods when awake or sleeping, using a diary that records such times. Unpublished data from our own series would suggest an error of up to one-tenth in misclassification of measurements made during waking and sleeping. No study has thus far shown the inaccuracy introduced, if any, in ambulatory measurements when ignoring one-quarter of recording time as described above.
Normative data for ambulatory monitoring has now been published. 49 A recent study from the same group using the least mean square method of analysis to account for the non-Gaussian distribution of the original cohort provides 90th and 95th percentiles for daytime and night-time values stratified according to sex and height. 50,51 Our own preference is for the data using the least mean square method. The criterions for defining hypertension in children are different when using data derived from office measurements as opposed to ambulatory monitoring, with higher values for daytime levels using 24-hour monitoring of normotensive children compared to measurements made in the clinic. 52 Findings in children with hypertension, however, are inconsistent. 44,53–56 Ambulatory devices allow assessment of systolic and diastolic pressures, expressed as mean and standard deviation of values during the 24-hour period, including daytime and night-time. The pressure load and dipping state, described below, can also be assessed.
The pressure load as assessed over 24 hours expresses the percentage of measurements above the 95th percentile, but provides no information regarding the amplitude and duration of the pressures above the 95th percentile. In adults, this load has been shown to be more accurate than mean pressures 57,58 in predicting damage to end organs. A recent review 59 suggested a load of less than one-quarter to be normal, and greater than half to be more closely related to damage to the end organs. Attempts have also been made 60 to determine the agreement between mean pressures greater than the 95th percentile and a load of 30% when diagnosing hypertension on the basis of ambulatory monitoring. This data, 60 and that from others, 61–63 suggests that mean pressures above the 95th percentile correlate better with a load in excess of 50%. 61–63
The physiological nocturnal dip in pressure, and the rise with waking, or the morning surge, has been well described in adults. The absence of any dip in adults is related to cardiovascular and cerebrovascular morbidity and mortality. 64–66 This relationship has not been described in children. A state of non-dipping, however, has been observed in several groups of children with a variety of renal diseases, and after renal transplantation. 67–70 Untreated children with secondary hypertension have been reported to develop nocturnal hypertension and the non-dipping state, as opposed to patients with primary hypertension who maintain their dipping state. 71 The morning surge as described in adults, 72,73 however, is not usually reported in children.
Normal Blood Pressure in Childhood
A large number of studies have been undertaken to establish the range of blood pressure found in normal children, 74–76 with the results for boys summarised in Figure 58-1 . As a general rule, a steady increase has been observed with age, with no significant difference between the sexes during childhood. Most studies, unfortunately, differ in some respect, for example, in the sizes of cuff used, with measurements taken with the patient sitting or supine, using different end-points for diastolic pressure, and so on.
These differences in technique make it difficult to interpret apparent differences between ethnic groups. Adult black individuals have an increased prevalence of hypertension and damage to target organs when compared with whites. 77 Nigerian children were found to have higher pressures than black American children. 78 Higher values for black than white children might be expected in view of the higher prevalence of hypertension in black adults. These were reported by the Bogalusa study, 79 but similar, 30,80–83 lower, 84–86 and no difference in values 87 have also been reported. A significant increase in the proportion of hypertensive 18-year-old black adolescents has also been reported, 88,89 albeit that another study 90 found no difference in the renin-angiotensin-aldosterone system when comparing black and white children and adolescents. It has been suggested 91 that height rather than age is the appropriate standard to which blood pressure should be related. After controlling for height, the effect of age on blood pressure disappears. It is also suggested, therefore, that evaluation of blood pressure in an individual should be based on height and weight rather than age. 80 It is not clear whether sexual maturation has an effect, independent of body mass, on blood pressure. 74
Obesity poses special problems because of the essential requirement for an adequate cuff in making measurements. Where adequate sizes have been used, obese adolescents have been found to have a higher incidence of hypertension. 86,92–94 Corrections have been made according to the circumference of the arm and the size of the cuff used in the measurement 95 ( Table 58-1 ). Levels of cholesterol and triglyceride in the serum do not correlate well with blood pressure, 79 but levels of glucose in the plasma 1 hour after a glucose load were found to correlate with blood pressure independently of weight. 96 The deleterious influence of salt on blood pressure in children has become clearer, and is discussed briefly later in this chapter. No difference was apparent in blood pressure between bottle- and breast-fed infants. 97
| Width of Bladder (cm) | Length of Bladder (cm) | |
|---|---|---|
| Newborns | 4 | 5–10 |
| Infants | 6 | 12 |
| 1–5 years | 8 | 15 |
| 6–9 years | 10 | 20 |
| 10 years and over | 13 | 23 |
| Obese adults | 15 | 30 |
| Adult thigh | 18 | 36 |
Normal Values for Blood Pressure Measured in the Clinic
Pressures during childhood vary physiologically with gender, age and height. The practising clinician requires standards with which to compare the blood pressure of individual patients. The most recent Fourth Report from the working group of the National High Blood Pressure Education Program in the United States now provides 50th, 90th, 95th, and 99th centiles for pressures obtained by auscultation in formats specific for gender, age, and height, and is widely accepted as the reference standard for normative values. 9 It provides data over and above that from the previous reports of the Task Force on Blood Pressure Control in Children, 30,32 giving comprehensive values for seven different centiles for height at each age from 1 to 17 years, as shown in Table 58-2 for boys, and Table 58-3 for girls. Despite this addition of new data, there is minimal change in the levels for gender, age, and height for the 90th and 95th percentiles from the last report. Additionally, the new data describes stages of hypertension, defining normotension as below the 90th percentile, pre-hypertension as between the 90th and 95th percentiles, the first stage of hypertension as between the 95th and 99th percentiles plus 5 mm Hg, and the second stage of hypertension as greater than the 99th percentile plus 5 mm Hg, similar to the seventh report of the joint national committee. 98 It provides guidance on the speed at which evaluation, treatment, and referral should be made in a child with elevated blood pressure. The age and gender specific centiles for blood pressure in boys and girls from birth to 12 months of age are shown in Figures 58-2 and 58-3 .
| Age, yr | BP Percentile | SBP, mm Hg | DBP, mm Hg | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Percentile of Height | Percentile of Height | ||||||||||||||
| 5th | 10th | 25th | 50th | 75th | 90th | 95th | 5th | 10th | 25th | 50th | 75th | 90th | 95th | ||
| 1 | 50th | 80 | 81 | 83 | 85 | 87 | 88 | 89 | 34 | 35 | 36 | 37 | 38 | 39 | 39 |
| 90th | 94 | 95 | 97 | 99 | 100 | 102 | 103 | 49 | 50 | 51 | 52 | 53 | 53 | 54 | |
| 95th | 98 | 99 | 101 | 103 | 104 | 106 | 106 | 54 | 54 | 55 | 56 | 57 | 58 | 58 | |
| 99th | 105 | 106 | 108 | 110 | 112 | 113 | 114 | 61 | 62 | 63 | 64 | 65 | 66 | 66 | |
| 2 | 50th | 84 | 85 | 87 | 88 | 90 | 92 | 92 | 39 | 40 | 41 | 42 | 43 | 44 | 44 |
| 90th | 97 | 99 | 100 | 102 | 104 | 105 | 106 | 54 | 55 | 56 | 57 | 58 | 58 | 59 | |
| 95th | 101 | 102 | 104 | 106 | 108 | 109 | 110 | 59 | 59 | 60 | 61 | 62 | 63 | 63 | |
| 99th | 109 | 110 | 111 | 113 | 115 | 117 | 117 | 66 | 67 | 68 | 69 | 70 | 71 | 71 | |
| 3 | 50th | 86 | 87 | 89 | 91 | 93 | 94 | 95 | 44 | 44 | 45 | 46 | 47 | 48 | 48 |
| 90th | 100 | 101 | 103 | 105 | 107 | 108 | 109 | 59 | 59 | 60 | 61 | 62 | 63 | 63 | |
| 95th | 104 | 105 | 107 | 109 | 110 | 112 | 113 | 63 | 63 | 64 | 65 | 66 | 67 | 67 | |
| 99th | 111 | 112 | 114 | 116 | 118 | 119 | 120 | 71 | 71 | 72 | 73 | 74 | 75 | 75 | |
| 4 | 50th | 88 | 89 | 91 | 93 | 95 | 96 | 97 | 47 | 48 | 49 | 50 | 51 | 51 | 52 |
| 90th | 102 | 103 | 105 | 107 | 109 | 110 | 111 | 62 | 63 | 64 | 65 | 66 | 66 | 67 | |
| 95th | 106 | 107 | 109 | 111 | 112 | 114 | 115 | 66 | 67 | 68 | 69 | 70 | 71 | 71 | |
| 99th | 113 | 114 | 116 | 118 | 120 | 121 | 122 | 74 | 75 | 76 | 77 | 78 | 78 | 79 | |
| 5 | 50th | 90 | 91 | 93 | 95 | 96 | 98 | 98 | 50 | 51 | 52 | 53 | 54 | 55 | 55 |
| 90th | 104 | 105 | 106 | 108 | 110 | 111 | 112 | 65 | 66 | 67 | 68 | 69 | 69 | 70 | |
| 95th | 108 | 109 | 110 | 112 | 114 | 115 | 116 | 69 | 70 | 71 | 72 | 73 | 74 | 74 | |
| 99th | 115 | 116 | 118 | 120 | 121 | 123 | 123 | 77 | 78 | 79 | 80 | 81 | 81 | 82 | |
| 6 | 50th | 91 | 92 | 94 | 96 | 98 | 99 | 100 | 53 | 53 | 54 | 55 | 56 | 57 | 57 |
| 90th | 105 | 106 | 108 | 110 | 111 | 113 | 113 | 68 | 68 | 69 | 70 | 71 | 72 | 72 | |
| 95th | 109 | 110 | 112 | 114 | 115 | 117 | 117 | 72 | 72 | 73 | 74 | 75 | 76 | 76 | |
| 99th | 116 | 117 | 119 | 121 | 123 | 124 | 125 | 80 | 80 | 81 | 82 | 83 | 84 | 84 | |
| 7 | 50th | 92 | 94 | 95 | 97 | 99 | 100 | 101 | 55 | 55 | 56 | 57 | 58 | 59 | 59 |
| 90th | 106 | 107 | 109 | 111 | 113 | 114 | 115 | 70 | 70 | 71 | 72 | 73 | 74 | 74 | |
| 95th | 110 | 111 | 113 | 115 | 117 | 118 | 119 | 74 | 74 | 75 | 76 | 77 | 78 | 78 | |
| 99th | 117 | 118 | 120 | 122 | 124 | 125 | 126 | 82 | 82 | 83 | 84 | 85 | 86 | 86 | |
| 8 | 50th | 94 | 95 | 97 | 99 | 100 | 102 | 102 | 56 | 57 | 58 | 59 | 60 | 60 | 61 |
| 90th | 107 | 109 | 110 | 112 | 114 | 115 | 116 | 71 | 72 | 72 | 73 | 74 | 75 | 76 | |
| 95th | 111 | 112 | 114 | 116 | 118 | 119 | 120 | 75 | 76 | 77 | 78 | 79 | 79 | 80 | |
| 99th | 119 | 120 | 122 | 123 | 125 | 127 | 127 | 83 | 84 | 85 | 86 | 87 | 87 | 88 | |
| 9 | 50th | 95 | 96 | 98 | 100 | 102 | 103 | 104 | 57 | 58 | 59 | 60 | 61 | 61 | 62 |
| 90th | 109 | 110 | 112 | 114 | 115 | 117 | 118 | 72 | 73 | 74 | 75 | 76 | 76 | 77 | |
| 95th | 113 | 114 | 116 | 118 | 119 | 121 | 121 | 76 | 77 | 78 | 79 | 80 | 81 | 81 | |
| 99th | 120 | 121 | 123 | 125 | 127 | 128 | 129 | 84 | 85 | 86 | 87 | 88 | 88 | 89 | |
| 10 | 50th | 97 | 98 | 100 | 102 | 103 | 105 | 106 | 58 | 59 | 60 | 61 | 61 | 62 | 63 |
| 90th | 111 | 112 | 114 | 115 | 117 | 119 | 119 | 73 | 73 | 74 | 75 | 76 | 77 | 78 | |
| 95th | 115 | 116 | 117 | 119 | 121 | 122 | 123 | 77 | 78 | 79 | 80 | 81 | 81 | 82 | |
| 99th | 122 | 123 | 125 | 127 | 128 | 130 | 130 | 85 | 86 | 86 | 88 | 88 | 89 | 90 | |
| 11 | 50th | 99 | 100 | 102 | 104 | 105 | 107 | 107 | 59 | 59 | 60 | 61 | 62 | 63 | 63 |
| 90th | 113 | 114 | 115 | 117 | 119 | 120 | 121 | 74 | 74 | 75 | 76 | 77 | 78 | 78 | |
| 95th | 117 | 118 | 119 | 121 | 123 | 124 | 125 | 78 | 78 | 79 | 80 | 81 | 82 | 82 | |
| 99th | 124 | 125 | 127 | 129 | 130 | 132 | 132 | 86 | 86 | 87 | 88 | 89 | 90 | 90 | |
| 12 | 50th | 101 | 102 | 104 | 106 | 108 | 109 | 110 | 59 | 60 | 61 | 62 | 63 | 63 | 64 |
| 90th | 115 | 116 | 118 | 120 | 121 | 123 | 123 | 74 | 75 | 75 | 76 | 77 | 78 | 79 | |
| 95th | 119 | 120 | 122 | 123 | 125 | 127 | 127 | 78 | 79 | 80 | 81 | 82 | 82 | 83 | |
| 99th | 126 | 127 | 129 | 131 | 133 | 134 | 135 | 86 | 87 | 88 | 89 | 90 | 90 | 91 | |
| 13 | 50th | 104 | 105 | 106 | 108 | 110 | 111 | 112 | 60 | 60 | 61 | 62 | 63 | 64 | 64 |
| 90th | 117 | 118 | 120 | 122 | 124 | 125 | 126 | 75 | 75 | 76 | 77 | 78 | 79 | 79 | |
| 95th | 121 | 122 | 124 | 126 | 128 | 129 | 130 | 79 | 79 | 80 | 81 | 82 | 83 | 83 | |
| 99th | 128 | 130 | 131 | 133 | 135 | 136 | 137 | 87 | 87 | 88 | 89 | 90 | 91 | 91 | |
| 14 | 50th | 106 | 107 | 109 | 111 | 113 | 114 | 115 | 60 | 61 | 62 | 63 | 64 | 65 | 65 |
| 90th | 120 | 121 | 123 | 125 | 126 | 128 | 128 | 75 | 76 | 77 | 78 | 79 | 79 | 80 | |
| 95th | 124 | 125 | 127 | 128 | 130 | 132 | 132 | 80 | 80 | 81 | 82 | 83 | 84 | 84 | |
| 99th | 131 | 132 | 134 | 136 | 138 | 139 | 140 | 87 | 88 | 89 | 90 | 91 | 92 | 92 | |
| 15 | 50th | 109 | 110 | 112 | 113 | 115 | 117 | 117 | 61 | 62 | 63 | 64 | 65 | 66 | 66 |
| 90th | 122 | 124 | 125 | 127 | 129 | 130 | 131 | 76 | 77 | 78 | 79 | 80 | 80 | 81 | |
| 95th | 126 | 127 | 129 | 131 | 133 | 134 | 135 | 81 | 81 | 82 | 83 | 84 | 85 | 85 | |
| 99th | 134 | 135 | 136 | 138 | 140 | 142 | 142 | 88 | 89 | 90 | 91 | 92 | 93 | 93 | |
| 16 | 50th | 111 | 112 | 114 | 116 | 118 | 119 | 120 | 63 | 63 | 64 | 65 | 66 | 67 | 67 |
| 90th | 125 | 126 | 128 | 130 | 131 | 133 | 134 | 78 | 78 | 79 | 80 | 81 | 82 | 82 | |
| 95th | 129 | 130 | 132 | 134 | 135 | 137 | 137 | 82 | 83 | 83 | 84 | 85 | 86 | 87 | |
| 99th | 136 | 137 | 139 | 141 | 143 | 144 | 145 | 90 | 90 | 91 | 92 | 93 | 94 | 94 | |
| 17 | 50th | 114 | 115 | 116 | 118 | 120 | 121 | 122 | 65 | 66 | 66 | 67 | 68 | 69 | 70 |
| 90th | 127 | 128 | 130 | 132 | 134 | 135 | 136 | 80 | 80 | 81 | 82 | 83 | 84 | 84 | |
| 95th | 131 | 132 | 134 | 136 | 138 | 139 | 140 | 84 | 85 | 86 | 87 | 87 | 88 | 89 | |
| 99th | 139 | 140 | 141 | 143 | 145 | 146 | 147 | 92 | 93 | 93 | 94 | 95 | 96 | 97 | |
| Age, Yr | BP Percentile | SBP, mm Hg | DBP, mm Hg | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Percentile of Height | Percentile of Height | ||||||||||||||
| 5th | 10th | 25th | 50th | 75th | 90th | 95th | 5th | 10th | 25th | 50th | 75th | 90th | 95th | ||
| 1 | 50th | 83 | 84 | 85 | 86 | 88 | 89 | 90 | 38 | 39 | 39 | 40 | 41 | 41 | 42 |
| 90th | 97 | 97 | 98 | 100 | 101 | 102 | 104 | 52 | 53 | 53 | 54 | 55 | 55 | 56 | |
| 95th | 100 | 101 | 102 | 104 | 105 | 106 | 107 | 56 | 57 | 57 | 58 | 59 | 59 | 60 | |
| 99th | 108 | 108 | 109 | 111 | 112 | 113 | 114 | 64 | 64 | 65 | 65 | 66 | 67 | 67 | |
| 2 | 50th | 85 | 85 | 87 | 88 | 89 | 91 | 91 | 43 | 44 | 44 | 45 | 46 | 46 | 47 |
| 90th | 98 | 99 | 100 | 101 | 103 | 104 | 105 | 57 | 58 | 58 | 59 | 60 | 61 | 61 | |
| 95th | 102 | 103 | 104 | 105 | 107 | 108 | 109 | 61 | 62 | 62 | 63 | 64 | 65 | 65 | |
| 99th | 109 | 110 | 111 | 112 | 114 | 115 | 116 | 69 | 69 | 70 | 70 | 71 | 72 | 72 | |
| 3 | 50th | 86 | 87 | 88 | 89 | 91 | 92 | 93 | 47 | 48 | 48 | 49 | 50 | 50 | 51 |
| 90th | 100 | 100 | 102 | 103 | 104 | 106 | 106 | 61 | 62 | 62 | 63 | 64 | 64 | 65 | |
| 95th | 104 | 104 | 105 | 107 | 108 | 109 | 110 | 65 | 66 | 66 | 67 | 68 | 68 | 69 | |
| 99th | 111 | 111 | 113 | 114 | 115 | 116 | 117 | 73 | 73 | 74 | 74 | 75 | 76 | 76 | |
| 4 | 50th | 88 | 88 | 90 | 91 | 92 | 94 | 94 | 50 | 50 | 51 | 52 | 52 | 53 | 54 |
| 90th | 101 | 102 | 103 | 104 | 106 | 107 | 108 | 64 | 64 | 65 | 66 | 67 | 67 | 68 | |
| 95th | 105 | 106 | 107 | 108 | 110 | 111 | 112 | 68 | 68 | 69 | 70 | 71 | 71 | 72 | |
| 99th | 112 | 113 | 114 | 115 | 117 | 118 | 119 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
| 5 | 50th | 89 | 90 | 91 | 93 | 94 | 95 | 96 | 52 | 53 | 53 | 54 | 55 | 88 | 56 |
| 90th | 103 | 103 | 105 | 106 | 107 | 109 | 109 | 66 | 67 | 67 | 68 | 69 | 69 | 70 | |
| 95th | 107 | 107 | 108 | 110 | 111 | 112 | 113 | 70 | 71 | 71 | 72 | 73 | 73 | 74 | |
| 99th | 114 | 114 | 116 | 117 | 118 | 120 | 120 | 78 | 78 | 79 | 79 | 80 | 81 | 81 | |
| 6 | 50th | 91 | 92 | 93 | 94 | 96 | 97 | 98 | 54 | 54 | 55 | 56 | 56 | 57 | 58 |
| 90th | 104 | 105 | 106 | 108 | 109 | 110 | 111 | 68 | 68 | 69 | 70 | 70 | 71 | 72 | |
| 95th | 108 | 109 | 110 | 111 | 113 | 114 | 115 | 72 | 72 | 73 | 74 | 74 | 75 | 76 | |
| 99th | 115 | 116 | 117 | 119 | 120 | 121 | 122 | 80 | 80 | 80 | 81 | 82 | 83 | 83 | |
| 7 | 50th | 93 | 93 | 95 | 96 | 97 | 99 | 99 | 55 | 56 | 56 | 57 | 58 | 58 | 59 |
| 90th | 106 | 107 | 108 | 109 | 111 | 112 | 113 | 69 | 70 | 70 | 71 | 72 | 72 | 73 | |
| 95th | 110 | 111 | 112 | 113 | 115 | 116 | 116 | 73 | 74 | 74 | 75 | 76 | 76 | 77 | |
| 99th | 117 | 118 | 119 | 120 | 122 | 123 | 124 | 81 | 81 | 82 | 82 | 83 | 84 | 84 | |
| 8 | 50th | 95 | 95 | 96 | 98 | 99 | 100 | 101 | 57 | 57 | 57 | 58 | 59 | 60 | 60 |
| 90th | 108 | 109 | 110 | 111 | 113 | 114 | 114 | 71 | 71 | 71 | 72 | 73 | 74 | 74 | |
| 95th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
| 99th | 119 | 120 | 121 | 122 | 123 | 125 | 125 | 82 | 82 | 83 | 83 | 84 | 85 | 86 | |
| 9 | 50th | 96 | 97 | 98 | 100 | 101 | 102 | 103 | 58 | 58 | 58 | 59 | 60 | 61 | 61 |
| 90th | 110 | 110 | 112 | 113 | 114 | 116 | 116 | 72 | 72 | 72 | 73 | 74 | 75 | 75 | |
| 95th | 114 | 114 | 115 | 117 | 118 | 119 | 120 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
| 99th | 121 | 121 | 123 | 124 | 125 | 127 | 127 | 83 | 83 | 84 | 84 | 85 | 86 | 87 | |
| 10 | 50th | 98 | 99 | 100 | 102 | 103 | 104 | 105 | 59 | 59 | 59 | 60 | 61 | 62 | 62 |
| 90th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 73 | 73 | 73 | 74 | 75 | 76 | 76 | |
| 95th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
| 99th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 84 | 84 | 85 | 86 | 86 | 87 | 88 | |
| 11 | 50th | 00 | 101 | 102 | 103 | 105 | 106 | 107 | 60 | 60 | 60 | 61 | 62 | 63 | 63 |
| 90th | 114 | 114 | 116 | 117 | 118 | 119 | 120 | 74 | 74 | 74 | 75 | 76 | 77 | 77 | |
| 95th | 118 | 118 | 119 | 121 | 122 | 123 | 124 | 78 | 78 | 78 | 79 | 80 | 81 | 81 | |
| 99th | 125 | 125 | 126 | 128 | 129 | 130 | 131 | 85 | 85 | 86 | 87 | 87 | 88 | 89 | |
| 12 | 50th | 102 | 103 | 104 | 105 | 107 | 108 | 109 | 61 | 61 | 61 | 62 | 63 | 64 | 64 |
| 90th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
| 95th | 119 | 120 | 121 | 123 | 124 | 125 | 126 | 79 | 79 | 79 | 80 | 81 | 82 | 82 | |
| 99th | 127 | 127 | 128 | 130 | 131 | 132 | 133 | 86 | 86 | 87 | 88 | 88 | 89 | 90 | |
| 13 | 50th | 104 | 105 | 106 | 107 | 109 | 110 | 110 | 62 | 62 | 62 | 63 | 64 | 65 | 65 |
| 90th | 117 | 118 | 119 | 121 | 122 | 123 | 124 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
| 95th | 121 | 122 | 123 | 124 | 126 | 127 | 128 | 80 | 80 | 80 | 81 | 82 | 83 | 83 | |
| 99th | 128 | 129 | 130 | 132 | 133 | 134 | 135 | 87 | 87 | 88 | 89 | 89 | 90 | 91 | |
| 14 | 50th | 106 | 106 | 107 | 109 | 110 | 111 | 112 | 63 | 63 | 63 | 64 | 65 | 66 | 66 |
| 90th | 119 | 120 | 121 | 122 | 124 | 125 | 125 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
| 95th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 81 | 81 | 81 | 82 | 83 | 84 | 84 | |
| 99th | 131 | 132 | 134 | 136 | 138 | 139 | 140 | 88 | 88 | 89 | 90 | 90 | 91 | 92 | |
| 15 | 50th | 107 | 108 | 109 | 110 | 111 | 113 | 113 | 64 | 64 | 64 | 65 | 66 | 67 | 67 |
| 90th | 120 | 121 | 122 | 123 | 125 | 126 | 127 | 78 | 78 | 78 | 79 | 80 | 81 | 81 | |
| 95th | 124 | 125 | 126 | 127 | 129 | 130 | 131 | 82 | 82 | 82 | 83 | 84 | 85 | 85 | |
| 99th | 131 | 132 | 133 | 134 | 136 | 137 | 138 | 89 | 89 | 90 | 91 | 91 | 92 | 93 | |
| 16 | 50th | 108 | 108 | 110 | 111 | 112 | 114 | 114 | 64 | 64 | 65 | 66 | 66 | 67 | 68 |
| 90th | 121 | 122 | 123 | 124 | 126 | 127 | 128 | 78 | 78 | 79 | 80 | 81 | 81 | 82 | |
| 95th | 125 | 126 | 127 | 128 | 130 | 131 | 132 | 82 | 82 | 83 | 84 | 85 | 85 | 86 | |
| 99th | 132 | 133 | 134 | 135 | 137 | 138 | 139 | 90 | 90 | 90 | 91 | 92 | 93 | 93 | |
| 17 | 50th | 108 | 109 | 110 | 111 | 113 | 114 | 115 | 64 | 65 | 65 | 66 | 67 | 67 | 68 |
| 90th | 122 | 122 | 123 | 125 | 126 | 127 | 128 | 78 | 79 | 79 | 80 | 81 | 81 | 82 | |
| 95th | 125 | 126 | 127 | 129 | 130 | 131 | 132 | 82 | 83 | 83 | 84 | 85 | 85 | 86 | |
| 99th | 133 | 133 | 134 | 136 | 137 | 138 | 139 | 90 | 90 | 91 | 91 | 92 | 93 | 93 | |
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