The prevalence of hypertension (HT) in children is 3.5%. 10-11% of children have increased blood pressure values. The prevalence of obesity is increasing. High blood pressure in childhood is a risk factor for adult hypertension and cardiovascular disease. Hypertension guidelines in children were published by the National Heart, Lung, and Blood Institute (NHLBI) in 1977, 1987, 1996 and 2004, and most recently by the American Academy of Pediatrics (AAP) in 2017. The last guideline emphasizes the use of 24-hour ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of HT.
At what age should blood pressure be measured in children?
In children who do not have any risk factors for hypertension, blood pressure measurements should be started from the age of 3 and the measurement should be repeated at annual health check visits. In children over 3 years of age with HT risk factors, blood pressure should be measured at every health check. Blood pressure measurement should be taken at every health check in children under 3 years of age with HT risk factors.
How should the size and placement of the sleeve be done?
The part of the blood pressure measuring devices that allows the measurement by wrapping on the upper or forearm and which is inflated is called a cuff or cuff. Cuffs of varying diameter and size are available for children and adults. Generally, cuff sleeve diameters of 18-26 / 22-36 cm are used in children and / 30-42 / 32-45 cm in adults. Choosing the right cuff is very important for accurate measurement of blood pressure. Pressures higher than intra-arterial pressure are measured with the small cuff and pressure measurements lower than normal arterial pressure with the large cuff. The size of the cuff should be approximately 40% of the upper arm circumference, and the circumference measurement should be made just in the middle of the distance between olecranon and acromion. The length of the sleeve should be 80-100% of this measured circumference and the width / length ratio should be at least 1: 2.
How should blood pressure measurement technique be?
Stimulant drugs and foods should not be taken before blood pressure measurement. After resting for 3-5 minutes in a quiet environment, blood pressure should be measured in a sitting position with the back leaning. In infants under 1 year of age, measurements should be made while lying in the supine position. In order for the measurement to be correct, it is desired that the heart rate is normal for the age during the measurement. Anxiety increases heart rate and blood pressure. After checking the size and location of the cuff, measurement is made with the auscultation method. The bell part of the stethoscope is placed at the level of the brachial artery in the cubital fossa. Measurements are made on the right arm of the patient while the arm is at heart level. Right arm should be preferred for repeated measurements. When aortic coarctation is suspected, blood pressure measurements of 4 extremities (right and left arm, right and left leg) should be made. If the arm is below the heart level, blood pressure can be measured as high as 10-12 mmHg due to the increased hydrostatic pressure with gravity. The cuff is inflated to 20-30 mmHg above the expected systolic blood pressure. Afterwards, it should be lowered slowly to 2-3 mmHg in each heartbeat. Systolic blood pressure is equal to the pressure at which the brachial artery pulse is first heard by auscultation (Korotkoff phase I). As the cuff is lowered under systolic pressure, the pulse continues until it suddenly stops (Korotkoff phase IV), and subsequently the sound disappears completely (Korotkoff phase V). Phase V is the recommended phase for determination of diastolic blood pressure in children. Sometimes this value is heard at 0 mmHg, in which case the measurement should be repeated and low pressure should be applied to the head of the stethoscope. When phase V is quite low, it can be regarded as phase IV diastolic blood pressure value.
What are the normal blood pressure values and hypertension diagnostic criteria in children?
- In children between the ages of 1-13
a. Normal blood pressure systolic and diastolic blood pressure values <90 percentile
b. Increased blood pressure (previously called prehypertension) systolic and / or diastolic blood pressure values> 90th percentile and <95th percentile, or 120/80 mmHg <95th percentile (whichever is lower). Increased blood pressure is important in predicting hypertension
c. Stage 1 hypertension with systolic and / or diastolic blood pressure> 95th percentile with <95th percentile + 12mmHg or 130/80 – 139/89 mmHg (whichever is lower)
D. Stage 2 hypertension systolic and / or diastolic blood pressure> 95 percentile + 12 mmHg or> 140/90 mmHg (whichever is lower)2. In children> 13 years of age
a. Normal blood pressure <120/80 mmHg
b. Increased blood pressure (previously called prehypertension) systolic blood pressure 120-129 mmHg with diastolic blood pressure value <80 mmHg
c. Stage 1 hypertension blood pressure 130/80 – 139/89 mmHg
d. Stage 2 hypertension blood pressure> 140/90 mmHg
How should the follow-up be in the diagnosis of hypertension?
Follow-up, evaluation and treatment decision depends on the high blood pressure. In children with stage 2 HT, further evaluation and drug treatment may be required in terms of end organ damage and clinical findings. Non-drug treatments (lifestyle, dietary changes) are recommended in children with a diagnosis of increased blood pressure, and blood pressure value should be checked again with auscultation after 6 months. If the blood pressure value is still high after 6 months, the blood pressure of the lower and upper extremities (right arm, left arm and one leg) should be checked and re-measured 6 months later. If the high blood pressure level still continues at the end of the 12th month (after 3 auscultatory measurements), ambulatory blood pressure monitoring (ABPM) should be performed in ambulatory blood pressure monitoring. If ABPM is not possible, home blood pressure measurements should be followed and noted. If the blood pressure value returns to normal, blood pressure screening should be returned to the annual health check.
Non-drug treatment recommendations and re-evaluation within 1-2 weeks are appropriate for children with stage 1 HT. Aortic coarctation should be excluded, and if blood pressure is still in Stage I when blood pressure is controlled by auscultation after 3 months, ABPM is recommended and appropriate diagnostic evaluation should be performed (such as nephrology, endocrinology). Stage 2 HT if the patient is symptomatic (blood pressure 30 mmHg higher than the 95th percentile or> 180/120 mmHg) should be taken to the pediatric emergency department. If the patient is asymptomatic, measurements from three extremities should be checked to exclude aortic coarctation, lifestyle recommendations should be made, and blood pressure measurement should be made again after 1 week. If the level of Stage II is still high in his control, diagnostic evaluation and ABPM should be done and drug treatment should be started.
What is ambulatory blood pressure measurement?
There is a better correlation between the risk of hypertensive cardiovascular complications and target organ damage in adults with ABPM than blood pressure values measured at the office. Although the data in children are more limited, it is emphasized that ABPM has an important role in the evaluation of hypertension. Blood pressure measurement is possible during daily activities and sleep. It is particularly useful in the clinical situation of white coat hypertension detected in children in hospital and office environments and is also helpful in determining the risk of increased blood pressure. According to the analysis of the data in the SHIP AHOY (Study of Hypertension in Pediatrics, Adult Hypertension Onset in Youth) study, the blood pressure value measured in adolescents at the office in two separate visits and in each visit, according to age, height and gender>
Which values should be interpreted as hypertension in ABPM?
Threshold values valid for the diagnosis of hypertension in ABPM are higher than office measurements due to the use of oscillometric technique, not performing auscultation, and taking active and / or ambulatory measurements when the patient is not at rest. Correlation between ABPM and office measurements is not good, and a single study of approximately 1000 children and adolescents in Central Europe is used for normal data in clinical practice.
Ambulatory pre-hypertension: office systolic blood pressure or diastolic blood pressure> 90th percentile, <95th percentile, mean ambulatory systolic or diastolic blood pressure <95th percentile, and ambulatory systolic or diastolic blood pressure burden between 25-50%. Ambulatory hypertension: office blood pressure> 95th percentile, mean ambulatory systolic or diastolic blood pressure> 95th percentile, and systolic or diastolic blood pressure burden between 25-50%
In 2016, European Society of Hypertension (ESH) guideline for HT threshold to be above the 95th percentile and accepted adult ambulatory blood (24-hour mean 130/80 mmHg, mean daytime 135/85 mmHg and mean night 125/75 mmHg) values lower than the pressure values are accepted for diagnosis. ABPM provides very useful information about the blood pressure pattern in patients with chronic kidney disease, diabetes, autonomic dysfunction, or episodic hypertension, and the blood pressure response in patients receiving therapeutic treatment.
