Accuracy of blood pressure measurement by the Dinamap monitor in infants and children

Indirect BPs measured by the Dinamap monitor, an oscillometric device, and the conventional auscultatory method were compared with the direct radial artery pressure in infants and children. There were 29 patients in the Dinamap group with a median age of 18 months (ranges 1 month to 16 years) and 20 patients in the auscultatory group with a median age of 3.5 years (ranges 3 months to 16 years). The direct radial artery pressures were recorded on a strip chart and the ranges of pressures were obtained for systolic, diastolic, and mean pressures. The range of the direct readings was converted to a weighted single reading, and comparisons were made between the direct and indirect readings. The linear regression equation between the direct (x) and the Dinamap (y) readings (with correlation coefficient) was y = 1.05x - 5.36 (r = .97) for systolic, y = 1.10x - 4.65 (r = .903) for diastolic, and y = 1.06x - 4.21 (r = .917) for mean pressures. The linear regression equation (with correlation coefficient) for the auscultatory pressure was y = 1.60x - 68.23 (r = .872) and y = 1.38x - 16.47 (r = .874) for diastolic pressures. The error was defined as the indirect reading minus the direct reading. The mean error +/- SD was -0.24 +/- 3.26 for systolic, 1.28 +/- 4.74 for diastolic, and 0.10 +/- 4.56 mm Hg for mean pressures by the Dinamap method. It was -1.65 +/- 6.68 for systolic, and 8.70 +/- 5.97 for diastolic pressures by the auscultatory method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of the oscillometric method to measure blood pressure in children

OBJECTIVE: The aim of this study is to analyze the substitution of the standard auscultatory method by the oscillometric blood pressure monitor, independently of the validity of the intraarterial blood pressure measurement. The accuracy of the automatic oscillometric monitor was compared to the auscultatory mercury manometer blood pressure measurement in apparently healthy school age children. METHODS: A device able to perform 3 simultaneous readings are used: one reading by the monitor and the others by two "blind" observers. We studied 72 school age children with the following characteristics: mean age 9.5 (6.1-16.1) and 39 males (54.2%). RESULTS: The difference for the systolic and diastolic blood pressure obtained by the monitor was in average + 6.2 mmHg and + 10.0 mmHg, respectively, when compared to the observer's readings. There was neither a good correlation nor a good agreement between the two observers and the monitor in the blood pressure determination. CONCLUSIONS: We concluded that the substitution of the standard auscultatory method for the non-invasive oscillometric method to measure blood pressure in school age children can not be generally recommended.     

Blood pressure in 6- to 45-month-old children. Apropos of a study of 264 children from nurseries

The systolic, diastolic and mean blood pressure and pulse rate were measured among 264 children aged 6 to 45 months, during routine check-up in 4 day-nurseries. We took the mean value of 3 successive measurements taken at one minute intervals on the upper arm of calm, asymptomatic children, with an automatic oscillometric monitor (Dinamap). When the mean systolic blood pressure was greater than 110 mmHg, the measurement was repeated. The results were related to weight, height and age and to personal and/or family history. The systolic pressure was steady with a 97th percentile at 110 mmHg. The diastolic pressure presented two levels: 97th percentile at 81 mmHg before 24 months and 73 mmHg afterwards. Nine children born to toxemic mothers, and 14 having required neonatal hospital care, had lower diastolic pressure. The other family or personal data were not linked to particular pressure groups.     

Cardiovascular effects of nasogastric tube feeding in the healthy preterm infant

Th systemic blood pressure (BP) and heart rate were estimated by the neonatal Dinamap 847 in 16 healthy preterm neonates in active sleep (AS) before, during and after milk feed by indwelling nasogastric tube. The mean arterial blood pressure (MAP) rose by 10.2% (P less than 0.01) and the diastolic pressure by 8.3% (P less than 0.05) during feeding. The systolic and pulse pressures also rose but individual variation rendered these changes insignificant. The heart rate increased by 6.3% (P less than 0.05) 10 min after the end of the feed. The degree of change in BP and heart rate was unrelated to body weight, gestational age, postnatal age, rate of feeding, volume or duration of the feed.     

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.     

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.     

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.     

Delivery room blood pressure percentiles of healthy,singleton, liveborn neonates

Background: Arterial blood pressure (BP) is one of the four vital signs that reflect cardiovascular status in neonates. The present study aimed to obtain BP percentiles among healthy, singleton, liveborn neonates between 34 and 43 weeks of gestation who were less than 1 h old. Methods: BP measurements were taken after birth in supine‐positioned neonates in the delivery room using an oscillometric device. A total of 982 well‐nourished neonates who did not require resuscitation, were not fetally malnourished, were not admitted to the neonatal intensive care unit and were without obvious congenital abnormalities were included in the study. Results: Sex‐ and type‐of‐delivery‐specific 5th and 95th percentiles BP measurements were obtained for gestation. Mean BP values for systolic, diastolic and mean of term neonates were 63.98 ± 12.29 mmHg, 38.34 ± 11.06 mmHg and 49.32 ± 11.33 mmHg, and late preterm neonates were 61.80 ± 12.46 mmHg, 33.17 ± 9.97 mmHg and 46.52 ± 10.8 mmHg, respectively. There were weak but significant correlations between birthweight, birth length and head circumference and systolic, diastolic and mean arterial BP values (r = 0.20, r = 0.15 and r = 0.20, respectively, P < 0.001). Neonates who were delivered vaginally had higher mean BP values for systolic, diastolic and mean than neonates delivered by cesarean section (P < 0.05). Female neonates had higher systolic BP values than male neonates (P < 0.05). Conclusion: Data presented in this study include sex‐ and delivery‐mode‐specific BP percentile curves using an oscillometric method and serve as a valuable reference for physicians in dealing with the management of singleton, liveborn late preterm and term newborns in the delivery room intensive care.     

ABPM vs office blood pressure to define blood pressure control in treated hypertensive paediatric renal transplant recipients

While 24-h ambulatory blood pressure monitoring (ABPM) is an established tool for monitoring antihypertensive therapy in adults, data in children are scarce. We retrospectively analysed whether office blood pressure (BP) is reliable for the diagnosis of BP control in 26 treated hypertensive paediatric renal transplants. Controlled office BP was defined as the mean of three replicate systolic and diastolic BP recordings less than or equal to the 95th age-, sex- and height-matched percentile on the three-outpatient visits closest to ABPM. Controlled ABPM was defined as systolic and diastolic daytime BP < or =95th distribution adjusted height- and sex-related percentile of the adapted ABPM reference. Eight recipients (30%) with controlled office BP were in fact categorized as having non-controlled BP by ABPM criteria. Overall, when office BP and ABPM were compared using the Bland and Altman method, the 95% limits of agreement between office and daytime values ranged from -12.6 to 34.1 mmHg for systolic and -23.9 to 31.7 mmHg for diastolic BP, and the mean difference was 10.7 and 3.9 mmHg respectively. Office readings miss a substantial number of recipients who are hypertensive by ABPM criteria. Undertreatment of hypertension could be avoided if ABPM is applied as an adjunct to office readings.     

Blood pressure in full-term healthy neonates

The blood pressure (BP) of 46 healthy full-term infants was studied in the first 6 consecutive days of life using the Dinamap. The BP gradually increased with age to peak at 4 or 5 days of age before subsiding a little at 6 days. There was a significant increase in BP values from the second to the third day of life in both the systolic and diastolic pressures during the waking state but not during sleep. The waking and sleeping BP, almost identical in the first day, diverged with increasing age, although no significant difference could be demonstrated between the respective values during the 6 days of study in systolic, diastolic, or mean arterial pressure. BP values obtained in the left and right upper limbs and right lower limb were similar for the respective days, with minor variations in pattern. The waking and sleeping heart rate, identical on the first day, also diverged with increase in age but again no significant difference was observed on the first 6 days. There was no correlation between the BP and heart rate on any of the 6 days. However, a positive correlation between the daily mean systolic pressure and heart rate only in the waking state was observed over the course of the 6-day study period.     

Correlation Between Blood Pressure Measurement by Non-invasive and Invasive Methods in Critically-ill Children

Objective

To determine the correlation of non-invasive blood pressure obtained by auscultatory and oscillometric methods, with invasive blood pressure in critically ill children.

Methods

We compared invasive with auscultatory and oscillometric blood pressures using paired t-test, Pearson’s correlation coefficient and Bland-Altman plot in 50 children (age 1-12 y) admitted in Pediatric intensive care unit.

Results

Systolic, diastolic, and mean arterial pressures of invasive methods significantly correlated with auscultatory and oscillometric methods (P<0.001). Auscultatory and oscillometric measurements under-estimated systolic arterial pressures [mean (SD) difference 5.4 (12.2) mmHg and 6.3 (14.0) mmHg, respectively; P<0.001] and overestimated diastolic arterial pressures [-4.1 (5.8) mmHg and -3.6 (7.2) mmHg; P<0.001] compared to invasive blood pressure.

Conclusion

Mean arterial pressure obtained by NIBP measurement is more closer than systolic or diastolic pressures, when compared with invasive blood pressure measurement.

     

Oscillometric and intra-arterial blood pressure measurements in the neonate: a comparison of methods

ABSTRACT. A number of methods exist to measure neonatal blood pressure, one of which involves oscillometric principles. This method is the functional basis of the Dinamap 847 which has been studied for accuracy and reproductibility in 398 paired comparisons with direct arterial measurements in nine neonates. The correlation between the Dinamap and direct arterial pressure values were excellent, although for systolic blood pressure the Dinamap tends to underestimate by 2.4 ± 3.9 mm Hg. The present study has shown the Dinamap to be a clinically reliable instrument for measuring neonatal blood pressure.     

Blood Pressure Profiles of a Group of African Children in the First Year of Life

Systolic blood pressure was measured at birth, every week till 6 months, then every month till 12 months in normal Cameroonian neonates in the two Yaounde teaching hospitals. Systolic arterial pressure in awake babies rose from a mean of 65.1 +/- 1.30 mmHg at birth to 80.59 +/- 2.16 mmHg at 6 weeks; 94.39 mmHg at 12 months. The majority of this rise (7 mmHg) took place during the first 2 weeks of life. Systolic blood pressure increased by an average 2.5 mmHg weekly in the first 6 weeks, 0.5 mmHg weekly from 6 weeks to 6 months, and 0.6 mmHg monthly from 6 to 12 months. Relationships between systolic blood pressure and various parameters, and systolic blood pressures trends are analysed. Systolic blood pressure was not influenced by birth weight, sex of children, or tribe of parents. There was a weak correlation between systolic blood pressure and body weight between 6 weeks and 6 months. Systolic blood pressure measurements taken at different ages were not correlated.     

Relation of arterial stiffness with gestational age and birth weight.

BACKGROUND: The cardiovascular risk of individuals who are born small as a result of prematurity remains controversial. Given the previous findings of stiffer peripheral conduit arteries in growth restricted donor twins in twin-twin transfusion syndrome regardless of gestational age, we hypothesised that among children born preterm, only those with intrauterine growth retardation are predisposed to an increase in cardiovascular risks. AIM: To compare brachioradial arterial stiffness and systemic blood pressure (BP) among children born preterm and small for gestational age (group 1, n = 15), those born preterm but having birth weight appropriate for gestational age (group 2, n = 36), and those born at term with birth weight appropriate for gestational age (group 3, n = 35). METHODS: Systemic BP was measured by an automated device (Dinamap), while stiffness of the brachioradial arterial segment was assessed by measuring pulse wave velocity (PWV). The birth weight was adjusted for gestational age and expressed as a z score for analysis. RESULTS: The 86 children were studied at a mean (SD) age of 8.2 (1.7) years. Subjects from group 1, who were born at 32.3 (2.0) weeks' gestation had a significantly lower z score of birth weight (-2.29 (0.63), p<0.001), compared with those from groups 2 and 3. They had a significantly higher mean blood pressure (p<0.001) and their diastolic blood pressure also tended to be higher (p = 0.07). Likewise, their brachioradial PWV, and hence arterial stiffness, was the highest of the three groups (p<0.001). While subjects from group 2 were similarly born preterm, their PWV was not significantly different from that of group 3 subjects (p = 1.00) and likewise their z score of birth weight did not differ (-0.01 (0.71) v -0.04 (1.1), p = 1.00). Brachioradial PWV correlated significantly with systolic (r = 0.31, p = 0.004), diastolic (r = 0.38, p<0.001), and mean (0.47, p<0.001) BP, and with z score of birth weight (r = -0.43, p<0.001). Multiple linear regression identified mean BP and z score of birth weight as significant determinants of PWV. CONCLUSION: The findings of the present study support the hypothesis that among children born preterm, only those with intrauterine growth retardation are disadvantaged as a result of increase in systemic arterial stiffness and mean blood pressure.     

Comparison of Dinamap 8100 with sphygmomanometer blood pressure measurement in a prepubertal diabetes cohort

OBJECTIVE: To compare the conventional sphygmomanometer with the semiautomated Dinamap 8100 (Critikon, Tampa, FL, USA) for the measurement of blood pressure in prepubertal children with insulin-dependent diabetes mellitus. METHODOLOGY: Blood pressure was measured using both methods in 61 prepubertal children (aged 8-13 years) on 189 occasions over 4 years. The measurements were compared using the Bland-Altman plot. Tracking correlations of blood pressure centiles over time were analyzed by the general estimating equation. RESULTS: Accuracy criteria of the Association for the Advancement of Medical Instrumentation were met and a British Hypertensive Society 'B' grading was reached. Differences in systolic and diastolic blood pressure were found between the two methods (P < 0.01). For systolic blood pressure, common correlations were 0.54 (Dinamap) and 0.51 (sphygmomanometer) and for diastolic blood pressure were 0.33 and 0.42, respectively. CONCLUSION: The Dinamap 8100 is an acceptable alternative in clinic practice and research for prepubertal children.     

Evaluation of the Omron MX3 Plus monitor for blood pressure measurement in adolescents

This study analyzed the accuracy/agreement of the Omron MX3 monitor on 165 adolescents. Blood pressure was measured by the automatic monitor connected in Y with the mercury column (three consecutive and simultaneous measures). The independent measures were analyzed, and the mean differences between systolic and diastolic measures for both methods were calculated and compared with British Hypertension Society (BHS) and Association for the Advancement of Medical Instrumentation (AAMI) criteria. The automatic monitor received the highest degree of BHS recommendations for systolic and diastolic blood pressures according to the BHS. The median (25th and 75th) difference between the observer and the monitor measurements was −2 (−6 and 1) mmHg for systolic and 0 (−3 and1) mmHg for diastolic pressures. The monitor also satisfies the AAMI standard for the studied population. In conclusion, the Omron MX3 Plus monitor can be considered reliable and valid for clinical practice and is in accordance with BHS and AAMI criteria.     

Elevated arterial blood pressure is associated with peri-intraventricular haemorrhage

In a prospective study, brain ultrasound scans were performed in 42 newborns (median birth weight 1700g, range 1020–3720 g; gestational age 32 weeks, 26–36) to reveal peri-intraventricular haemorrhage (PIVH) (grades I–IV) as well as echodensities (ED) and/or periventricular leucomalacia (PVL). ECG and arterial blood pressure were recorded on magnetic tape at 8h intervals during the first 24 h of life for further computer analysis. Heart rate (HR) and its variability (HRV) indices RMSM (long-term variability) and RMSSD (short-term variability), together with their coefficients of variation, were computed. Systolic (SBP), diastolic (DBP), and mean blood pressures (MBP) were detected as average values for 2-min stationary segments together with the respective minima and maxima. The indices of variability and their coefficients of variation were computed for the arterial pressure. PIVH was found in 12 newborns and ED in 8 (of whom two developed PVL). The remaining 22 served as controls. Neither HR, HRV nor BP variability differed between the groups. DBP was higher in the group with PIVH (39 mmHg) when compared to both the controls (33 mmHg,P<0.05) and the ED group (32 mmHg,P<0.01). MBP behaved respectively (45 mmHg, 38 mmHg, 37 mmHg,P<0.01). SBP behaved also similarly when gestational age and birth weight were used as covariates (57 mmHg, 48 mmHg, 47 mmHg,P<0.01).Our results suggest that elevated diastolic, mean and systolic blood pressure are significantly associated with peri-intraventricular haemorrhage in preterm newborn infants.     

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.     

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.     

Direct monitoring of arterial blood pressure in depressed and normal newborn infants during the first hour of life

Direct systolic, diastolic, and mean arterial blood pressure was continuously recorded during the first 64 min of life in 150 newborn infants. The data were analyzed at 4, 8, 16, 32, and 64 min. The highest blood pressure values were noted during the first few minutes of life in all newborn infants, with a rapid drop within 4 to 8 min. Decline in blood pressure was more gradual throughout the remainder of the observation period. Blood pressures of depressed newborn infants at birth (Apgar scores 6 or less at 1 and 5 min) were compared to those of normal newborn infants (Apgar scores 7 or greater at 1 and 5 min). The former demonstrated generally higher systolic pressures during the first 16 min and diastolic pressures at 4 min when infants were compared by their 1 min Apgar scores and higher diastolic pressures at 4 min when the infants were compared by their 5 min Apgar scores.