Home blood pressure in children and adolescents: a comparison with office and ambulatory blood pressure measurements

Aim: To compare BP measurements of children and adolescents using different methods office BP (OBP), ambulatory BP monitoring (ABPM) and home BP measurement (HBPM) and to study their correlations. Method: Individuals were evaluated between 5 and 15 years of age who had been referred because of a previous high BP. OBP was measured with the OMRON‐705CP. Three measurements were carried out at 5‐min intervals. HBPM were taken using the same device, two measurements at 5‐min intervals in the morning and in the evening during 7 days. ABPM was performed using the SpaceLabs 90207 monitors. Results: A total of 109 children and adolescents were evaluated (9.82 ± 2.63 years), 52.3% boys, 56.9% non‐white. The office systolic BP (SBP) was lower than in daytime ABPM (p < 0.001) but similar HBPM (p = 0.294), and the office diastolic BP (DBP) was lower than daytime ABPM (p < 0.001) and in HBPM (p = 0.035). The SBP and DBP at HBPM was lower than daytime ABPM (p < 0.001). Daytime ambulatory BP was more closely associated with home readings (SBP r = 0.731 and DBP r = 0.616) than with office’s readings (SBP r = 0.653 and DBP r = 0.394). Conclusion: The BP of children and adolescents varies depending on the place and manner of measurement. ABPM presents better correlation with HBPM than with the office measurements.     

Estimation of gestational age in the neonate: a comparison of clinical methods.

A combined evaluation of almost all the proposed morphologic and neurologic criteria for estimating gestational age in the neonate was performed on 710 newborns of 28 to 44 weeks' gestation. It is concluded that (1) the neurologic criteria used by Dubowitz et al in combination with the external (morphologic) criteria of Farr et al give very accurate results of estimation of the gestational age; (2) equally accurate results can be obtained if those criteria with the lowest correlation coefficients--namely, are and leg recoil, degree of edema, and appearance of the genitalia--are omitted; and (3) the use of only nine external criteria, the assessment of which is easier to perform on sick babies, gives an estimation of gestational age that is accurate for clinical purposes (r=0.878).     

Blood pressure in the neonate: three non-invasive oscillometric pressure monitors compared with invasively measured blood pressure

AIM: To compare blood pressure in neonates obtained from three different oscillometer blood pressure monitors (Dinamap, Criticare, Hewlett-Packard) with arterial blood pressure (Hewlett-Packard' invasive unit). STUDY DESIGN: A total of 32 randomized, non-invasive blood pressure series, each consisting of three measurements from each monitor, were obtained from 20 neonates (birthweight 531-4660 g). Each measurement was compared with the invasive pressure. RESULTS: Two factors appear to have a systematic effect on the difference between oscillometric and invasive pressure (the measurement deviance): the size of the infant, e.g., the arm circumference, and the monitor system. For small infants, the non-invasively measured value tends to be too high. The deviance is partly reversed for larger infants (dependency on size significant for mean and diastolic pressure, p < 0.001). The difference between monitor systems is clearly significant (p < 0.001). Hewlett-Packard gives the lowest pressure values for all pressures. Thus, Criticare and Dinamap tended to show values too high in the smallest infants, while Hewlett-Packard tended to give values too low in larger infants. Birthweight, present weight and arm circumference affected measurement deviance approximately equally strongly, while factors such as the infant's sex, need of breath support and umbilical or radial arterial line were non-significant. CONCLUSIONS: Blood pressure should preferably be measured invasively in severely ill neonates and preterm infants, being aware of pitfalls with measurements using different oscillometer monitors and the size/arm circumference of the infant.     

Phase-contrast magnetic resonance angiography measurements of global cerebral blood flow in the neonate

Cerebral blood flow (CBF) alterations are important in pathogenesis of neonatal ischemic/hemorrhagic brain damage. In clinical practice, estimation of neonatal CBF is mostly based on Doppler-measured blood flow velocities in major intracranial arteries. Using phase-contrast magnetic resonance angiography (PC-MRA), global CBF can be estimated, but there is limited neonatal experience. The objective of this study was to gain experience with PC-MRA for the determination of global CBF in neonates. In infants eligible for MRI, PC-MRA global CBF was determined by measuring volume blood flow in both internal carotid arteries (ICAs) and basilar artery (BA). Thirty newborns (GA, 25.7-42.1 wk; weight, 1050-5858 g; postconceptional age, 225-369 d) were investigated. Total PC-MRA CBF ranged from 27 to 186 mL/min. Significant correlations between PC-MRA CBF and postconceptional age and weight were detected. When calculating PC-MRA measured CBF per kilogram body weight, brain perfusion was about stable over the range of postconceptional ages and ranged between 11 and 48 mL/min/kg (median, 25 mL/min/kg). In conclusion, neonatal PC-MRA CBF seems to be a useful technique to estimate noninvasive CBF.     

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.     

Blood pressure in the neonate

The paper by Dannevig et al. in this issue of Acta Paediatrica carefully compares the agreement between blood pressure measurements made by three non-invasive blood pressure monitors with those made from an indwelling intra-arterial catheter. Non-invasive blood pressure monitoring is not particularly accurate for making measurements in neonates and generally overestimates the blood pressure as observed by others. Clinicians thus should be wary about using non-invasive blood pressure techniques as substitutes for monitoring by means of an intra-arterial catheter and transducer.     

Non-invasive blood pressure measurements and aortic blood flow velocity in neonates

We studied the systolic blood pressure difference between the upper and the lower extremities in healthy newborn infants and the effect of the isthmic narrowing of the aorta on the possible difference. The blood pressure was measured with an oscillomerric blood pressure device from every extremity of 36 healthy infants aged 2–5 days. A Doppler echocardiography was performed for each infant to measure the aortic blood flow velocity in the ascending aorta and in the aortic arch above and below the isthmic narrowing. The mean blood pressure readings (S.D.) were the following: the right arm 76.8 (7.3)/48.1 (6.9), the left arm 77.5 (7.4)/51.6 (7.0), the right thigh 77.7 (7.1)/40.7 (5.8), the left thigh 76.8 (6.4)/39.6 (5.8), the right calf 75.5 (7.1)/46.6 (5.7) and the left calf 77.1 (8.6)/48.7 (6.7). The aortic blood flow was faster below the isthmic narrowing of the aorta (1.15 ± 0.19 m/s) than in the ascending aorta (0.93 ± 0.12 m/s) or in the aortic arch above the isthmus (0.99 ± 0.15 m/s). The calculated pressure gradient between the ascending aorta and aorta below the isthmus was 2.0 ± 1.8 mmHg and between opposite sides of the isthmus 1.5 ± 1.2 mmHg. Unlike in childhood and adolescence, the systolic blood pressure in the lower extremities of healthy newborn infants is not higher than in the upper extremities. The physiological narrowing of the aortic arch does not explain this phenomenon. If blood pressure measurements are performed on a neotrate to rule out aortic coarctation, the readings obtained must be interpreted in respect to normal values in newborns.     

Hyphema and elevated intraocular pressure in a neonate

A female neonate delivered vaginally at term was noted 12 hours after birth to have a 20% hyphema, layered temporally. Intraocular pressure in the affected eye was 46 mm Hg. She was treated with intravenous and topical medications, with normalization of pressure within 6 hours. The hyphema cleared completely within 72 hours.     

Blood pressure disorders in the neonate: hypotension and hypertension

Although many sick newborns are treated for hypotension and hypertension, the normal physiologic blood pressure range ensuring appropriate organ perfusion is uncertain. Treatment decisions are based on statistically defined gestational and postnatal age-dependent normative blood-pressure values, combined with clinical intuition, because of difficulties evaluating organ perfusion and adequacy of cerebral oxygen delivery. Early-onset hypotension usually results from the combined effects of abnormal peripheral vasoregulation, myocardial dysfunction, and hypovolemia. Volume administration is the primary initial therapy but its use can be associated with significant untoward effects, especially in preterm infants, and should be limited to 10-20 mL/kg of isotonic saline. If the blood pressure cannot be normalized, dopamine should be added, and sometimes followed by adrenaline (epinephrine) and corticosteroids. Hypertension, most often caused by congenital or acquired renovascular disease or volume overload, needs a thorough search for the etiology and cautious treatment, so that blood pressure does not fall too quickly or too low.     

Doppler ultrasonic brachial blood pressure measurements in normal Chinese neonates: a preliminary report

The purpose of this study was to determine brachial blood pressures in normal Chinese neonates using a Doppler ultrasonic blood pressure monitor (Roche Arteriosonde 1020). The systolic (SP) and diastolic (DP) pressures of 100 healthy, full-term Chinese neonates were determined in triplicate under resting conditions. The pulse pressures (PP) were derived from the SP and DP. Correlation studies reveal significant positive correlation between age and PP (r = 0.34, P less than 0.0002), between weight and SP (r = 0.23, P less than 0.02) and between weight and PP (r = 0.40, P less than 0.02). No significant difference exists between blood pressures of males and females (P greater than 0.05). Comparison with three Western studies reveals that our mean SP is the lowest (1-3). This may be due to technical factors, e.g. different Doppler ultrasonic device, anthropometric factors or true genetic or environmental differences.     

Low cerebral blood flow: a risk factor in the neonate.

Among 19 infants in whom cerebral blood flow had been determined a few hours after birth, four died during the first days or weeks after birth, all with massive intracranial hemorrhage. The other infants were examined at 9 to 12 1/2 months of age by means of clinical neurologic evaluation, developmental psychologic assessment (Cattell), EEG, and cranial computed tomography. Six of the ten infants who had had CBF of 20 ml/100 gm/minute or less had developed cerebral atrophy as demonstrated at autopsy or by CT scan, none with neonatal flows above 20 had done so. Only one in the low flow group had developed completely normally, whereas abnormal development was found in only a minority of the high flow group. No other neonatal observation had such a clear relationship to later development. It is concluded that CBF of 20 or less during the first hours of life is critical.     

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