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.     

24 hour blood pressure monitoring in healthy and hypertensive children

24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.     

24 hour blood pressure monitoring in healthy and hypertensive children.

24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.     

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.     

Home, clinic, and ambulatory blood pressure monitoring in children with chronic renal failure

Ambulatory blood pressure monitoring (ABPM) provides superior information for diagnosis and treatment of pediatric hypertension, but for reasons of practicality, clinic blood pressure measurements (CBP) are still the primary diagnostic tool. Regular home blood pressure measurements (HBP) may be an alternative to ABPM, but this technique awaits validation in practice. We analyzed the concordance of ABPM, CBP and HBP in 118 pediatric patients (3-19 y) with chronic renal failure. HBP readings (10.5 +/- 5.4 per patient) were averaged for one week around the day of ABPM and CBP. Mean arterial pressure (MAP) measured by HBP (84.0 +/- 10 mm Hg) was significantly lower than both CBP (86.1 +/- 14.1 mm Hg, P< 0.05) and daytime ABPM (90.3 +/- 10.4 mm Hg, P< 0.05). HBP detected hypertensive patients with greater specificity (82 versus 70%), but lower sensitivity (52 versus 70%) than CBP. The fraction of patients rated erroneously hypertensive was 23% with CBP, but only 14% with HBP. The 95% limits of agreement with ABPM were narrower for HBP (-23 to10 mm Hg) than for CBP (-30 to 21 mm Hg). CBP, but not HBP measurements, were less precise in the upper BP range. The accuracy of HBP measurements did not change with use over a six months time period. In conclusion, HBP was superior to CBP in predicting ABPM, but neither CBP nor HBP detected hypertension with enough sensitivity or specificity to replace ABPM. The greater specificity of HBP compared with CBP makes it a more suitable tool for diagnosis, rather than screening, of hypertension in children.     

Day- and night-time blood pressure elevation in children with higher grades of renal scarring

OBJECTIVE: We used 24-hour ambulatory blood pressure measurement (ABPM) to screen for early changes in children with renal scarring compared with healthy controls, and we investigated correlations between the extent of renal damage and blood pressure (BP).Study design Untreated patients (n = 61) with renal scars associated with recurrent urinary tract infection and vesico-ureteric reflux were investigated and compared with 904 healthy controls. RESULTS: A significant positive correlation between the extent of renal scarring and systolic and diastolic BP standard deviation score (SDS) was found by using ABPM. Mean systolic day-time BP SDS in ABPM was significantly elevated in girls with renal scars compared with healthy controls, but failed to be significant in boys. Mean systolic and diastolic night-time BP SDS were significantly elevated in patients. Compatible with these results, diastolic dipping was significantly lower in patients compared with controls. CONCLUSIONS: The increase in BP obtained by ABPM is positively correlated with the degree of scarring in our group of patients. Elevated night-time BP might be the most sensitive indicator of BP elevation in these children.     

24小时动态血压监测直立性高血压患儿血压类型的病例对照研究

目的采用24 h动态血压(ABPM)方法探讨直立性高血压(OHT)患儿的血压类型。方法选取2009年10月至2013年9月在中南大学湘雅二医院(我院)儿童晕厥门诊就诊或住院的患儿,以不明原因晕厥及先兆晕厥为主诉,经直立倾斜试验确诊为OHT者为OHT组。与OHT组年龄及性别匹配,选择同期来我院儿童保健门诊检查的健康儿童为对照组。OHT组和对照组均行ABPM监测,观察收缩压昼夜差值、舒张压昼夜差值,24 h、日间、夜间平均收缩压和舒张压参数,并探讨血压类型。结果 OHT组40例,男23例,女17例,年龄(11.5±1.9)岁。对照组40例,男22例,女18例,年龄(10.6±2.4)岁。1收缩压昼夜差值对照组高于OHT组,(9.8±3.3)vs(8.4±4.7)mm Hg,P0.05。OHT组24 h、日间、夜间的平均收缩压和舒张压稍高于对照组(P0.05)。舒张压昼夜差值对照组稍高于OHT组(P0.05)。2OHT组以非勺型血压为主(72.5%),对照组以勺型血压为主(55.0%),两组血压类型差异有统计学意义(P=0.012)。结论 OHT患儿收缩压昼夜差值较正常儿童明显降低,血压类型以非勺型血压多见,多数患儿血压昼夜节律消失。     

Home blood pressure monitoring in diabetes.

Forty three children with diabetes were recruited to evaluate home blood pressure monitoring using an electronic oscillometric sphygmomanometer (Philips HP5330). This device was found to be simple to use and reliable. It fulfilled the accuracy criteria of the American Association for the Advancement of Medical Instrumentation for both systolic and diastolic blood pressure and those of the British Hypertension Society for systolic blood pressure. Thirty eight children successfully measured their own blood pressure at home and taught other family members to do the same. The results indicate that home blood pressure monitoring is of value in the management of diabetic children.     

Random-zero sphygmomanometer, Rose's tape, and the accuracy of the blood pressure measurements in children.

In the Cardiovascular Risk in Young Finns project, blood pressure (BP) was measured in 3549 randomly selected children aged 6-18 y in 1980, and 2887 and 2500 of the same individuals in 1983 and 1986, respectively. An ordinary mercury sphygmomanometer (OMS) was used in the first two surveys and a random-zero sphygmomanometer (RZS) in the third survey. Systolic and diastolic BP were lower when measured with an RZS than with an OMS and the shape of the age-related BP curve obtained with an RZS was significantly different from that obtained with an OMS, because low BP values were apparently measured more accurately with the former. Use of the RZS did not affect the distribution of the BP values. Rose's tape readings were used to evaluate the effect of training and to control the accuracy of the BP measurements. According to Rose's tape readings, Korotkoff's 4th phase BP was more difficult to measure accurately than 5th phase (p = 0.002). The mean values for the differences between the correct and actual BP readings on the Rose's tape were -1.2 mm Hg (SD 2.1) for systolic BP, 8.3 mm Hg (SD 13.6) for diastolic Korotkoff's 4th phase BP, and 1.2 mm Hg (SD 7.0) for diastolic Korotkoff's 5th phase BP, with a negative value indicating that the BP phase was measured lower than the correct value. Terminal digit preference was present in each survey to such an extent that it could have hampered the reaching of reliable conclusions from the data obtained with an OMS. The bias caused by terminal digit preference was obviated by the RZS.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

动态血压监测在儿童肾脏疾病中的临床研究

目的 研究儿童肾脏疾病中的动态血压(ABP)的特点.方法 以33例肾脏疾病患儿为研究对象,采用ABPM6100仪进行动态血压测量(ABPM),受试对象均未服用降压药物.以1997年德国1141名健康儿童的ABP值作为正常参考值.结果 夜间高血压发生率高于日间高血压发生率;夜间收缩/舒张压负荷(29.1±34.5)%/(24.9±34.3)%和指数(0.95±0.11)/(0.90±0.18)明显大于日间收缩/舒张压负荷(12.9±23.6)%/(9.3±19.1)%和指数(0.88±0.09)/(0.77±0.12);肾脏疾病患儿夜间收缩/舒张压下降率为(6.6±6.0)%/(8.8±10.2)%,明显低于正常值(13±6)%/(23±9)%;高达24例(72.7%)患儿夜间收缩压和(或)舒张压下降率为"非杓型",即使在正常血压者中也有72.7%的"非杓性"发生率.在33例患儿中随机血压(CBP)升高者5例,均有ABP升高;CBP正常者28例,但其中6例ABP升高.结论 ABPM能发现儿童肾脏疾病中的夜间高血压和血压昼夜节律的异常,为调整用药时机和更全面有效地控制血压提供依据,弥补了传统血压测量的不足;并能发现隐匿性高血压,可以早期发现高血压前期,从而有利于随访和尽早干预.     

Clinical evaluation and comparison of the Infrasonde, Arteriosonde, and mercury sphygmomanometer in measurement of blood pressure in children.

Both systolic and diastolic pressures can be measured in children with the mercury sphygmomanometer, the Arteriosonde and the Infrasonde. Estimates made blindly with these instruments were compared with directly measured intra-arterial blood pressures in 50 children aged between 4 days and 14 years. Systolic and diastolic estimates with the three techniques showed highly significant correlations with simultaneous intra-arterial measurements (P less than 0.001). The Infrasonde diastolic estimates were least satisfactory and the slope of the regression line against the intra-arterial pressure differed significantly from unity (y=0.54x+29.53). In 11 small children a satisfactory diastolic estimate could not be obtained with the mercury sphygmomanometer. While the mercury sphygmomanometer should remain the standard hospital equipment, an Arteriosonde would be valuable if it is difficult to hear Korotkoff's sounds on auscultation and if a diastolic pressure is required. For research investigations into childhood blood pressure an Arteriosonde or mercury sphygmomanometer, coupled with a device to exclude observer bias, is probably most suitable. Although the Infrasonde is not sufficiently accurate for research purposes, it is acceptable for routine ward use.     

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.     

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。     

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??Objective To discuss the changes of ambulatory blood pressure monitoring??ABPM?? in children with vasovagal syncope ??VVS??.Methods A total of 72 children ??VVS group??32 males??40 females??mean age ??10.98±1.86??years?? were enrolled in this study??who came from Children Syncope Outpatient Department or Inpatient Department of the Second Xiangya Hospital of Central South University from Sep 2008 to Feb 2010.After confirmed diagnosis of VVS by positive head-up tilt test ??HUTT????each patient was given ABPM.Forty healthy children ??19 males??21 females??mean age 10.24 ± 2.01 years?? were as controls ??control group??.Parameters of ABPM in children were analyzed.SPSS 17.0 software was used for the statistical analysis of these data.Results ??1??Mean pressure??24-hour mean systolic pressure ??24hSBP????24-hour mean diastolic pressure ??24hDBP????daytime mean systolic pressure ??DSBP?? and nighttime mean systolic pressure ??NSBP?? in VVS group were higher than those of the control group ??P??0.05??.??2??Blood pressure pattern??the ratio of non-spoon pressure pattern was higher than that of spoon pressure pattern with VVS ??67%vs.18%??P ??0.05??.NDBP ??P??0.05?? and NSBP ??P ??0.05?? were decreased and the systolic pressure differences and diastolic pressure differences in the daytime and at nighttime were higher in spoon pressure pattern than those of non-spoon pressure pattern with VVS ??P??0.05??.??3??Diagnostic experimental evaluation??the specificity??sensitivity??diagnostic coincidence??positive predict value and negative predict value of non-spoon pattern of ambulatory blood pressure pattern to VVS was 82.5%??66.67%??72.32%??87.27% and 57.89%??respectively.The Youden index was 45.28%.Conclusion There is autonomic nerve adjustment imbalance in children with VVS during asymptomatic time periods??especially the sympathetic nerve.The non-spoon pattern rate of fluctuation curve of ambulatory blood pressure in VVS children is higher??which is of diagnosis value to VVS children.     

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.     

Twenty-four-hour ambulatory blood pressure profiles in liver transplant recipients

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has proven to have better reproducibility than office blood pressure (BP) and is increasingly used for the study of hypertension in children and adolescents. The aim of our study was to assess 24-h BP profiles and to compare the results of office BP measurements with ABPM in stable liver transplant recipients transplanted before the age of 18 yr. ABPM was performed in 29 patients (nine males, 20 females), aged 3.9-24.8 yr (median 10.8 yr). The investigation was conducted 1.1-11.5 yr (median 5.1 yr) following transplantation. ABPM confirmed hypertension in one out of three office hypertensive patients. Seven patients (24%), whose office BP recordings were within the normotensive range, were reclassified as hypertensive. Non-dippers (n = 17), arbitrarily defined as patients with less than 10% nocturnal fall in BP, were similarly distributed among patients with ambulatory normotension and ambulatory hypertension (chi(2), p = 0.79). In addition, non-dippers showed a negative correlation between 24-h total urinary albumin excretion and both systolic and diastolic nocturnal decline in BP (Rho = -0.48, p < 0.05 and Rho = -0.86, p < 0.01, respectively). Our study found office BP readings to be poorly representative of 24-h BP profile. Larger studies are needed to confirm our observations as well as to determine whether routine BP measurements in the follow-up of paediatric liver transplant recipients should be based solely on office BP.     

Longitudinal data of blood pressure and pulse frequency during childhood (author's transl)

From 1968-1980 the development of blood pressure and pulse frequency in 221 healthy boys and 230 healthy girls aged 2-16 years was studied longitudinally. An automatic blood pressure device recording on a paper tape pulse frequence as well was used. Systolic readings are taken at the first appearance, diastolic readings at the disappearance of the Korotkoff sounds. A steady increase of the systolic, and to a lesser extent, of the diastolic pressure can be observed. Boys have a more pronouned increase of systolic pressure than girls. From year 2-16 the 50th percentile increases from 90 mm Hg to 128 mm Hg in boys and from 92 mmHg to 116 mm Hg in girls. The 50th percentile of diastolic pressure increases from 61 to 66 mm Hg in boys and 65 to 71 mm Hg in girls. Pulse frequency of boys is comparable to that of girls. The 50th percentile decreases from 100 to 75 beats. Increasing age is paralleled by decreasing pulse frequency.     

Assessment of Doppler ultrasound to measure systolic and diastolic blood pressures in infants and young children.

A recently developed instrument uses the Doppler shift technique to detect vessel wall movement, and it has been suggested that in conjunction with a conventional sphygmomanometer systolic and diastolic blood pressures can be measured. A controlled study was carried out in 20 children recovering from cardiac surgery where direct intra-arterial measurements (one observer) were compared with independent measurements using the Doppler instrument (2 observers). Systolic pressures measured directly and by Doppler technique correlated well and there was no significant difference between intra-arterial and indirect measurements whether the latter were taken by doctors or by nurses. In contrast, direct and indirect diastolic pressure measurements correlated poorly and were significantly overestimated with a mean difference of 6-25 mmHg (range +25 to -10) for doctors, and 4-25 mmHg (range +20 to -10) for nurses. Thus, the instrument adequately measured systolic blood pressure, but in our hands did not give precise measurements for diastolic blood pressure.