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.

     

Circulatory responses in children with unexplained syncope evaluated by continuous non-invasive finger blood pressure monitoring

Cardiovascular responses on active standing in children with unexplained syncope were investigated with continuous non-invasive finger artery pressure monitoring (Finapres). We examined 34 symptomatic patients (13 boys and 21 girls), aged 8–16 years, and 24 age-matched controls. Finger blood pressure and heart rate were monitored continuously for 5 min in the supine position and for 10 min while standing. Ten of 34 patients developed fainting symptoms with hypotension during upright posture (fainters). In the initial standing phase (0–30 s), two prominent abnormal blood pressure responses were found in patients: a marked decrease 45 f 18/23 ± 8 mmHg and a prolonged recovery time (16.5 ± 2.9 versus 27.7 ± 13.6 s), which appeared to be based on impaired vasoconstriction. Either or both abnormalities were observed in 21 (62%) of the 34 patients and in 2 (8%) of the controls. In addition, fainters also had a more marked increase in heart rate during standing compared with non-fainters. Our findings suggested that more than half of children with syncope had abnormal cardiovascular reflexes in the initial phase which appeared to be associated with vasodepressor syncope. The active standing test with a continuous beat-to-beat blood pressure recording has a high sensitivity in detecting abnormalities of autonomic function in patients with unexplained syncope.     

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 CHILDREN WITH DIABETES MELLITUS

ABSTRACT. Blood pressure measurements were evaluated in 151 children aged 2–19 years old with insulin-dependent diabetes mellitus (DM) of a duration of few months to 15 ½ years. Compared with a reference group, the diabetic children had lower diastolic blood pressure (DBP) shortly after start of DM. There was no difference for the systolic blood pressure (SBP). After duration of diabetes of 5 years there were no significant differences in SBP and only significantly lower DBP in girls (median difference 5 mmHg, p <0.01), while the difference in boys is insignificant (median difference 2 mmHg, p =0.32). In a model describing the intraindividual variation in blood pressure and its dependence on age, weight and height it was found that age was insignificant when weight and height were included. For DBP height was also insignificant when weight was included. For the 9 children with retinal microaneurysms the average SBP was significantly higher than expected for diabetic children of that weight and height.     

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.     

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.     

Noninvasive assessment of blood pressure variability in preterm infants

The feasibility of measuring blood pressure (BP) variability by a noninvasive beat-to-beat finger arterial BP device (Finapres) was assessed in preterm infants. By application of the finger cuff around the infant's wrist, time and frequency domain (spectral power) analysis of noninvasive beat-to-beat BP signals were compared with intra-arterial measurements. A fast Fourier Transform was used to compute the spectral power density from 128-s periods. The low-frequency band (LF; 0.04-0.15 Hz) is partly associated with baroreflex activity. The high-frequency band (HF; 0.4-1.5 Hz) is associated with respiratory activity. In eight subjects above 1000 g, reliable signals could be obtained. We observed a high correlation between noninvasive and intra-arterial beat-to-beat systolic BP values (mean r value +/- SD, 0.87 +/- 0.11), with a gain close to 1 (mean gain +/- SD, 1.0 +/- 0.4 mm Hg/mm Hg). Finapres estimated beat-to-beat systolic BP changes more accurately than diastolic values. We found a very high amount of linear coupling, expressed as coherence function, between the power spectra of noninvasive and intra-arterial systolic BP measurements. For systolic BP, the (pooled) group mean +/- SEM coherence values were 0.93 +/- 0.00 and 0.91 +/- 0.01 for LF and HF fluctuations, respectively (NS). The wrist method of Finapres in neonates has limited value in estimating absolute BP but is useful in a clinical research situation, where identification of beat-to-beat changes in systolic BP is more important. Finapres provides a noninvasive tool for investigating autonomic cardiovascular regulation (baroreflex sensitivity, spectral analysis of BP fluctuations) in neonates.     

Feasibility of noninvasive continuous finger arterial blood pressure measurements in very young children, aged 0-4 years

Our goal was to study the feasibility of continuous noninvasive finger blood pressure (BP) monitoring in very young children, aged 0-4 y. To achieve this, we designed a set of small-sized finger cuffs based on the assessment of finger circumference. Finger arterial BP measured by a volume clamp device (Finapres technology) was compared with simultaneously measured intra-arterial BP in 15 very young children (median age, 5 mo; range, 0-48), admitted to the intensive care unit for vital monitoring. The finger cuff-derived BP waveforms showed good resemblance with the invasive arterial waveforms (mean root-mean-square error, 3 mm Hg). The correlation coefficient between both methods was 0.79 +/- 0.19 systolic and 0.74 +/- 0.24 diastolic. The correlation coefficient of beat-to-beat changes between both methods was 0.82 +/- 0.18 and 0.75 +/- 0.21, respectively. Three measurements were related to measurement errors (loose cuff application; wrong set-point). Excluding these erroneous measurements resulted in clinically acceptable measurement bias (-3.8 mm Hg) and 95% limits of agreement (-10.4 to + 2.8 mm Hg) of mean BP values. We conclude that continuous finger BP measurement is feasible in very young children. However, cuff application is critical, and the current set-point algorithm needs to be revised in very young children.     

BLOOD PRESSURE IN DANISH CHILDREN and ADOLESCENTS

Abstract. Ibsen, K. Kaas (University Paediatric Clinic, Children's Hospital, Fugle-bakken, Copenhagen, Denmark). Blood pressure in Danish children and adolescents. Acta Paediatr Scand, 70:27, 1981.–Blood pressure was measured in 946 Danish schoolchildren aged 7 to 18 years. The children had been randomly selected and serve as an urban reference population. Blood pressure was measured in 52 different schools, with the same Random-Zero-Sphygmomanometer, and all pressures were measured by the same person, under standardized conditions, to eliminate as many sources of error and uncertainties as possible. For both sexes an age-dependent significant increase in both systolic and diastolic blood pressure was observed. For both the systolic and the diastolic pressures, significant differences in blood presure measured before and after blood testing were observed.     

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.     

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 SWEDISH SCHOOL CHILDREN

ABSTRACT, Systolic and diastolic blood pressure were measured in 1642 Swedish school children aged 12, 14, or 16 years. They represented 71% of all children in these age groups in the municipality where the investigation was done. The blood pressure was measured with an automatic, oscillometric blood pressure monitor. The systolic blood pressure increased significantly with age in both sexes. Boys aged 14 or 16 years had significantly higher systolic blood pressure than girls of the same ages.     

Circadian blood pressure changes in untreated children with kidney disease and conserved renal function

Abstract Ambulatory blood pressure monitoring over 24 h was applied in 31 children with kidney disease, aged 3–19 (median 11) years, in the absence of renal insufficiency and without antihypertensive therapy. Median creatinine clearance was 112ml/min/1.73m². Ambulatory blood pressure monitoring revealed that eight patients (26%) were hypertensive during the daytime, compared to 62% through casual recordings obtained in the office and 38% when blood pressure was taken at home. Nocturnal hypertension was detected by ambulatory monitoring in six patients, two of whom had normal blood pressure in the daytime. Median nocturnal dipping was 13% for systolic and 21% for diastolic blood pressure, i.e. similar to healthy children. Rhythm analysis recognized a distorted circadian pattern for systolic and/or diastolic blood pressure in eight patients. In conclusion, ambulatory blood pressure monitoring allows the evaluation of hypertension more reliably than casual recordings in the office. Nocturnal hypertension, as a major risk factor for renal deterioration, is detected in a similar proportion as daytime hypertension in almost 20% of untreated children with kidney disease and normal renal function.     

24小时血压监测评价儿童神经介导性晕厥治疗效果

目的：探讨24 h血压监测（ABPM）评价儿童神经介导性晕厥（NMS）治疗效果。方法：选择2010年 2月至2012年8月以不明原因晕厥或先兆晕厥为主诉,经直立倾斜试验（HUTT）诊断明确的NMS患儿28例,其中男12例,女16例,年龄6～13岁。经健康教育结合口服补液盐（ORS）治疗后复查临床症状、HUTT及ABPM。结果：（1）28例NMS患儿中,血管抑制型22例,混合型5例,心脏抑制型1例。（2）治疗效果随访：临床症状好转率96%（27/28）,HUTT好转率64%（18/28）。（3）ABPM随访：全天平均收缩压、全天平均舒张压、日间平均收缩压、日间平均舒张压、夜间平均收缩压、夜间平均舒张压、收缩压昼夜差值、舒张压昼夜差值在治疗前后差异均无统计学意义（P>0.05）。（4）ABPM参数昼夜变化模式：“勺型血压”从治疗前的29%（8/28）提高到治疗后的50%（14/28）;“非勺型血压”从治疗前的71%（20/28）下降到治疗后的50%（14/28）。结论：ABPM作为一种有效、客观、无创性监测方法,对评价儿童NMS治疗效果具有一定的临床意义。     

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.     

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.     

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.     

Blood pressure studies in black children.

Blood pressure measurements were obtained under office conditions by auscultatory method, using appropriate cuff sizes, in 1,668 healthy black children (827 boys and 841 girls) ranging in age from 4 to 17 years. We found no significant difference between the mean systolic blood pressure of black children in our study and that of whites as reported in the literature. However, mean diastolic blood pressure was lower in black children. Some black children (3.6%) were found to have blood pressure more than 2 standard deviations above the mean for their age and should be closely observed for developing hypertensive cardiovascular changes.