A comparison of non-invasive methods of blood pressure measurement in normotensive and hypertensive pregnant women

We compared two types of automatic non-invasive blood pressure measuring device with sphygmomanometey in 47 normotensive and 38 hypertensive women in the third trimester of pregnancy. An automatic oscillometric device (Accutor) and a volume-clamp device (Finapres) significantly underestimated the diastolic pressure as measured by the fourth Korotkoff sound using a Hawksley random zero sphygmomanometer. The mean difference between the sphygmomanometer and Accutor measurement of diastolic blood pressure was +3.1 mmHg in the normotensive women and +8.3 mmHg in the hypertensive women (P = 0.001). The mean difference between the sphygmomanometer and Finapres measurement of diastolic blood pressure was +6.1 mmHg in the normotensive women and +11.5 mmHg in hypertensive women (P = 0.003). The increased use of continuous non-invasive devices to monitor blood pressure in women with hypertension should be accompanied by sound knowledge of their limitations in this group of patients.     

Comparison of invasive blood pressure monitoring versus normal non-invasive blood pressure monitoring in ST-elevation myocardial infarction patients with percutaneous coronary intervention

BackgroundHypotension post percutaneous coronary intervention (PCI) causes stent thrombosis and reduced coronary perfusion, which aggravate myocardial ischemia and lead to patient death. Therefore, the accuracy and timeliness of blood pressure monitoring (BPM) are crucial for the nursing of patients post PCI. However, it is still controversial whether invasive blood pressure monitoring (IBPM) or non-invasive blood pressure monitoring (NIBPM) should be used for patients post PCI, and the magnitude of their assistance for patients’ recovery remains unclear.MethodsA randomized controlled trial was performed in this study. 126 ST-segment elevation myocardial infarction (STEMI) patients post PCI were recruited and randomly divided into two groups (NIBPM group n = 63; IBPM group n = 63).ResultsClinical characteristics and physiological outcomes of participants received different BPM methods were collected and analyzed to compare the effects of these two methods on the nursing of PCI patients. Compared to NIBPM group, IBPM assisted to shorten the time of myocardial ischemia, promote coronary reperfusion, reduce the occurrence of cardiovascular disease and other complications, and ultimately reduce the mortality of patients post PCI.ConclusionThe application of IBPM contributed to reduce the occurrence of complications, shorten the time of vascular reperfusion, and guide treatment of clinicians in time.     

全身麻醉中连续无创动脉血压监测与有创动脉血压监测的比较

目的 评价麻醉期间TL-300系统测得的连续无创血压(continuous non-invasive arterial pressure,CNAP)和有创血压(invasive arterial pressure,IAP)监测的一致性和安全性.方法 择期全身麻醉手术患者72例,麻醉诱导前将动脉导管置入非优势手的桡动脉内行IAP监测,另一侧手臂连接TL-300系统行CNAP监测,记录IAP及相应时间点CNAP,以及相关的并发症.结果 CNAP与IAP所测SBP、DBP和MAP偏倚分别为(-0.6±7.0)、(-7.8±9.8)和(-5.8±6.2)mmHg(1 mmHg=0.133kPa),一致性界限分别为-14.6～13.4 mmHg、-27.4～11.8 mmHg、-18.2～6.6 mmHg,在其相应的一致性界限范围内所占比值分别为95.2％、96.1％和94.9％.两种BP监测方法的SBP、DBP和MAP的相关系数r分别为0.927、0.711和0.903 (P＜0.01).均未发生肢体缺血、坏死、感觉异常.结论 TL-300CNAP和IAP比较,有较高的相关性和一致性,提供无创实时连续、准确的BP监测,可安全用于全身麻醉手术患者.     

Comparison of femoral arterial blood pressure with radial arterial blood pressure and noninvasive upper arm blood pressure in the reperfusion period during liver transplantation

PURPOSE: The reperfusion period during liver transplantation is hemodynamically unstable. Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes. We sought to compare femoral arterial blood pressure (FABP) with radial arterial blood pressure (RABP) and noninvasive upper arm blood pressure (NIBP) in the reperfusion period. METHODS: Thirty-six adult living donor liver recipients were enrolled in this prospective study. Blood pressures in 3 locations were simultaneously recorded from 1 minute before reperfusion to 15 minutes after reperfusion. We evaluated agreements between FABP and RABP and between FABP and NIBP using intraclass correlation coefficients. Also, we investigated the rates of postreperfusion syndrome (PRS) based on the measurements from 3 locations. RESULTS: After reperfusion, the mean and diastolic RABP agreed more with the corresponding FABP than NIBP. However, systolic NIBP showed high agreement with FABP from 3 to 10 minutes after reperfusion in contrast with the moderate agreement between systolic RABP with FABP, and systolic values of NIBP than RABP were closer to FABP. The rates of PRS based on FABP, RABP, and NIBP measurements were 50.0% (18/36), 80.6% (29/36), and 50.0% (18/36), respectively. CONCLUSIONS: We believe that NIBP in addition to RABP may be considered to be a reliable alternative when FABP is not available to evaluate hemodynamic instability in the reperfusion period during liver transplantation.     

Validation of inflationary non-invasive blood pressure monitoring in adult surgical patients

Oscillometric determination of blood pressure may be advantageous, as cuff inflation requires lower cuff pressure and shorter duration than deflation. In this observational study, we compared the blood pressure value, cuff pressure, and duration of cuff inflation between a prototype of inflationary non-invasive blood pressure (NIBP) and conventional deflationary NIBP in adult patients during anesthesia. Three hundred and twenty-three pairs of measurements were obtained from 64 subjects. The bias and precision of systolic pressure and diastolic pressure were 2.9 ± 8.3 and 5.6 ± 6.1 mmHg, respectively. Inflationary NIBP could better determine NIBP with lower cuff pressure than deflationary NIBP (124 ± 22 vs. 160 ± 33 mmHg, p < 0.05). Inflationary NIBP could also determine NIBP more quickly (13.0 ± 2.3 vs. 32.7 ± 13.6 s, p < 0.05). These data suggest that inflationary NIBP may reduce cuff-related discomfort and complications, and has reasonable accuracy compared to deflationary NIBP in adult surgical patients.     

Doppler waveform analysis in evaluation of occlusive arterial disease in the lower limb: comparison with distal blood pressure measurement and arteriography

Three Doppler waveform parameters were related to ankle/brachial systolic pressure (A/B) index and angiography in 75 patients with lower limb arterial occlusive disease (AOD). Doppler signals were obtained from ankle arteries, and following spectral analysis pulse rise time (PRT), systolic width (SW) and pulsatility index (PI) were calculated. All three waveform parameters were significantly correlated with A/B index, and a 20% reduction could be predicted with an accuracy of 93 to 80% (corrected for chance, kappa, 81 to 52%). A significant correlation was also found between the three Doppler parameters and the angiographic assessment, i.e. the non-diseased, single- and multisegmentally diseased limbs, however, the accuracy in diagnosing angiographic stenoses was not as good as when pressure measurement was used for reference. Thirteen of the patients had high ankle pressures despite significant angiographic stenoses, and generally the Doppler examination was normal in these cases. Considering the waveform parameters individually, PRT and SW demonstrated almost identical results when compared to pressure measurement as well as angiography, whereas PI seemed clearly inferior. It is concluded that simple Doppler waveform parameters may accurately predict the haemodynamic significance of proximal AOD.     

An evaluation of a new continuous blood pressure monitoring system in critically ill patients

STUDY OBJECTIVE: To determine if the DxTek monitor, which is a device that measures blood pressure (BP) noninvasively and continuously by means of pulse velocity and wave shapes derived from the pulse oximeter optical plethysmograph and electrocardiogram is as accurate as an oscillometric cuff device when compared with intraarterial BP measurement. DESIGN: Prospective, comparative study. SETTING: University Medical Center. PATIENTS: 28 intensive care unit patients. INTERVENTIONS: Blood pressures were reported every minute by intraarterial catheters and DxTek and every 10 minutes by an oscillometric monitor for 2 to 5 hours. DxTek calibration was performed initially and when specified patient manipulations by caretakers were performed (on average, every 100 minutes). Comparisons with intraarterial pressure included: 1) DxTek calibrated with arterial catheter pressure, 2) DxTek calibrated with oscillometric pressure, and 3) oscillometric pressure. MEASUREMENTS AND MAIN RESULTS: When comparing oscillometric pressure to intraarterial pressure, the averages of the mean differences (bias) were -4.0 mmHg for systolic (SBP) and < 1.5 mmHg for diastolic (DBP) and mean (MAP) pressures. The averages of the standard deviation of the differences (precisions) were 9.6, 6.4, and 6.3 mmHg, respectively. With the DxTek device calibrated to intraarterial pressure, comparison of the DxTek pressure to intraarterial pressure resulted in a bias < OR = 0.5 mmHg for all three pressures and an average precision of 10.1 mmHg for SBP, 6.0 mmHg for DBP, and 6.7 mmHg for MAP. With the DxTek device calibrated to the oscillometric pressure, the DxTek pressure compared to the intraarterial pressure resulted in average biases of -5.1, -0.8, and -2.2 mmHg and average precisions of 11.1, 7.7, and 8.1 mmHg for SBP, DBP, and MAP, respectively. CONCLUSIONS: The DxTek monitor provides continuous, noninvasive BP measurements with an accuracy comparable to oscillometric devices.     

Noninvasive blood pressure measurement in the upper and lower limbs of anaesthetized children

A group of 50 children, aged 5 months to 15 years, and who were undergoing routine surgery under general anaesthesia, were studied to investigate the difference in noninvasive blood pressure readings obtained from inflatable cuffs placed on the upper arm and the lower leg. In contrast to adult data, it was found that the blood pressure measured from the leg in children aged 8 years and under, was significantly lower than that measured from the arm. The leg cuff measurements could not, however, be reliably used to predict arm blood pressure.     

An accuracy evaluation of the T-Line Tensymeter (continuous noninvasive blood pressure management device) versus conventional invasive radial artery monitoring in surgical patients

Continuous beat-to-beat arterial blood pressure (BP) monitoring with a simultaneous arterial waveform display is typically achieved with an invasive arterial catheter. We evaluated a noninvasive device, the T-Line Tensymeter, that provides a calibrated arterial pressure waveform from which continuous BP measurements and heart rate may be computed by either a bedside host monitor or the tensymeter device itself. In 25 patients given general anesthesia, we measured systolic, mean, and diastolic BPs via the tensymeter and compared these measurements with those obtained from the contralateral radial artery catheter. Data were analyzed using the Bland Altman test to determine agreement between the two systems. The mean +/- sd bias and precision (mm Hg) were as follows: 1.7 +/- 7.0 and 5.7 +/- 4.4 for systolic BP; 2.3 +/- 6.9 and 5.7 +/- 4.5 for diastolic BP; and 1.7 +/- 5.3 and 4.0 +/- 4.8 for mean BP. Noninvasive pressures from the tensymeter-produced arterial waveform agreed with simultaneous contralateral BPs measured from arterial catheters within an acceptable clinical range for a limited population of surgical patients studied over a systolic arterial BP range from 41 to 189 mm Hg without significant temporal performance degradation. The tensymeter may enable physicians to circumvent arterial cannulation in certain circumstances (such as with low- or intermediate-risk procedures) on patients when beat-to-beat BP measurement is desirable.     

Direct comparison of repeated same-day self and ambulatory blood pressure monitoring

BACKGROUND AND AIM: The relative roles of self and ambulatory blood pressure monitoring (self BPM, ABPM, respectively) have yet to be clearly defined despite accumulating evidence of self BPM benefits, particularly in hypertension management. In particular, measurements comparable to ABPM have been documented with self-measurement, usually twice daily over one or more days. Nevertheless, ABPM offers a series of recordings performed throughout the day that can be invaluable during drug treatment. Consequently, this study evaluated 18 normotensive and 79 hypertensive patients, including 21 not taking hypotensive agents, and measured their blood pressure at least every 2 h while they were also undergoing ABPM. METHODS AND RESULTS: Self-measurement was performed between five and 12 times during the day with 77% of subjects preferring self BPM rather than daytime ABPM. When compared with the closest ABP measurement, mean systolic and diastolic pressures were not significantly different throughout the day in both normotensive and hypertensive patients. However, a comparison of a series of ABPM hourly averages (three readings performed closest to the respective self BPM reading) throughout the day in all hypertensive subjects found ABPM readings to be slightly but significantly lower (3.3 systolic, 2.2 mmHg diastolic; P < 0.05). CONCLUSION: It is concluded that multiple self-measurements throughout the day provides comparable information to daytime ABPM, is preferred by most patients, and should be a cost-effective alternative in the diagnosis and management of hypertension.     

Measurement and evaluation of home blood pressure monitoring with particular emphasis on evaluating anti-hypertensive effects using a home blood pressure distribution diagram

Tight blood pressure control over a long period is important to prevent end-organ damage to the brain, heart, and kidneys, and to avoid the complications of hypertension. Control requires an accurate evaluation of treatment through an appropriate monitoring of home blood pressure. In this study, we evaluated a method of home blood pressure monitoring, in which we propose a home blood pressure distribution diagram to evaluate the effectiveness of anti-hypertensive therapy. 1 ) In home blood pressure measurements, the first reading was high, while the second and third readings were essentially similar and thus stable. 2 ) Home blood pressure showed great daily variations, thus necessitating the use of the mean blood pressure over a fixed period, and not the individual blood pressure readings. The mean (morning, mid-day, and evening) over a one-week period was unstable, while the readings were stable over a three-week period. 3 ) The diagrams showing the distribution of home blood pressure measurements obtained in the morning and at night over a long period allowed the degree of early morning hypertension and the effectiveness of long-term blood pressure control to be assessed, and thus were useful for selecting anti-hypertensive agents. 4 ) In elderly patients, a mid-day systolic pressure of 100 mmHg or less (particularly 90 mmHg or less) resulted in the onset of symptoms of excessive hypotensive effects, such as lightheadedness and fainting, which affected ADL and QOL. 5 ) Because of great daily variations, it is difficult to achieve the blood pressure target of 130/80 mmHg or less in patients with hypertension associated with diabetes mellitus or renal insufficiency. 6 ) The home blood pressure distribution diagram facilitated an understanding of the status of anti-hypertensive therapy by patients, and was useful for motivating patients to continue treatment.