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Arterial blood pressure (BP) is a fundamental cardiovascular variable, is routinely measured in perioperative and intensive care medicine, and has a significant impact on patient management. The clinical reference method for BP monitoring in high-risk surgical patients and critically ill patients is continuous invasive BP measurement using an arterial catheter. A key prerequisite for correct invasive BP monitoring using an arterial catheter is an in-depth understanding of the measurement principle, of BP waveform quality criteria, and of common pitfalls that can falsify BP readings. Here, we describe how to place an arterial catheter, correctly measure BP, and identify and solve common pitfalls. We focus on 5 important steps, namely (1) how to choose the catheter insertion site, (2) how to choose the type of arterial catheter, (3) how to place the arterial catheter, (4) how to level and zero the transducer, and (5) how to check the quality of the BP waveform.

Objective The aim of this study was to compare invasive and noninvasive monitoring of blood pressure (BP) in patients on inotropes. Settings and design This study was carried out in the ICU of a tertiary care centre. The design was comparative analytical. Patients and methods Thirty-six adult patients receiving inotropes with invasive arterial BP monitoring were studied. Systolic and diastolic BPs were recorded simultaneously using invasive (radial arterial cannula) and noninvasive (Philips Intellivue MP-60 oscillometric monitor attached to the opposite arm) methods every 30 min. Statistical analysis Agreement (precision) between both the methods was assessed using Bland-Altman analysis. A difference of more than 10 mmHg was considered clinically unacceptable. Linear regression of difference with invasive BP and analysis of variance with Tukey's correction of difference with the number of inotropes were carried out. Results Overall, 1400 pairs of systolic and diastolic BP measurements were obtained. Systolic and diastolic pressures showed a difference of 2.3±16.9 and 0.7±10.6 mmHg, respectively. In all, 93.4% of systolic and 98.6% of diastolic pressure measurements were within the limits of agreement. The difference was clinically acceptable in 54.2% of measurements of systolic and 74.1% of diastolic measurements. Both systolic and diastolic BP differences were correlated with the number of inotropes that the patient was receiving. Conclusion Noninvasive BP measurement using an oscilllometric monitor (Philips Intellivue MP-60) is not a reliable alternative to invasive intra-arterial measurement in patients receiving inotropes. The observed difference increased with the number of inotropes that the patient was receiving.

Background The management of hypertensive disorders of pregnancy (HDP) during hospitalization requires an accurate blood pressure (BP) measurement, mainly by invasive intra-arterial reading. Nevertheless, little is known about the precision of non-invasive (NI) central BP measurements in HDP. We aimed to assess the accuracy of NI central BP assessment in comparison to invasive BP measurement in HDP. This cross-sectional study included all patients with HDP that were admitted to university hospitals for high BP control, from December 2018 till December 2019, and 10 healthy matched non-hypertensive controls. Patients were compared for demographic, anthropometric, and echocardiographic data. In all subjects, invasive BP assessment was done by radial arterial cannulation and NI assessment of BP was performed by an oscillometric automated device (Mobil-O-Graph); the comparison was done after initial control of BP. Results One hundred patients were included and divided into 3 groups (pre-existing hypertension (HTN), gestational HTN, and pre-eclampsia). There was no statistically significant difference between NI central and invasive methods in measuring both systolic BP (SBP) (126.39 ± 14.5 vs 127.43 ± 15.3, p = 0.5) and diastolic BP (82.41 ± 9.0 vs 83.78 ± 8.9, p = 0.14) among the total studied population. A strong positive correlation was found between NI central and invasive SBP (r = 0.96, p Conclusion Non-invasive measurement of BP using oscillometric automated devices is as accurate as the invasive method, and it is a practical safe method in pregnant women with hypertensive disorders (CTR no. = NCT04303871).

BACKGROUND AND PURPOSE: Reports investigating the relationship between in-procedure blood pressure (BP) and outcomes in patients undergoing endovascular thrombectomy (EVT) due to anterior circulation stroke are sparse and contradictory. ----- METHODS: Consecutive EVT-treated adults (modern stent retrievers, BP managed in line with the recommendations, general anesthesia, invasive BP measurements) were evaluated for associations of the rate of in-procedure systolic BP (SBP) and mean arterial pressure (MAP) excursions to >120%/120% was independently associated with lower ILV, while higher in-procedure mean SBP/MAP was associated with lower odds of hemorrhages. mRS 0-2 was achieved in 75/155 (48.4%) evaluated patients (nine had missing mRS data). Higher rate of SBP/MAP excursions to >120% and higher reference SBP/MAP were independently associated with higher odds of mRS 0-2, while higher ILV was associated with lower odds of mRS 0-2. Rate of SBP/MAP excursions to

The objectives were to describe the associations between splenic reservoir mobilization and pharmacological changes in blood pressure (BP), the normal daily variability of BP, and the variation in BP between measurements obtained at a veterinary hospital and at home. A group of horses from a research herd (research group) and a group of healthy client-owned horses presented to a hospital (hospital group) were studied. Invasive BP and splenic volume were measured in the research group while hyper- and hypotension were induced by phenylephrine and acepromazine, respectively. Noninvasive blood pressure (NIBP) and ultrasonographically estimated splenic volume (by 2 observers) were measured on three consecutive days in research group horses. Noninvasive BP was measured in the hospital and the home environment in the hospital group at three time points. The change in splenic volume was highly correlated with the change in systolic BP after phenylephrine administration (r = −0.97, P ≤ .001), and there was no significant change in splenic volume or correlation with changes in BP after acepromazine administration. Noninvasive BP had low daily variability (coefficient of variation [CV] = 9%–11%), and splenic volume had high daily variability (CV = 30%–32%) but was reproducible between observers (intraclass correlation coefficient = 0.70). Horses in the hospital group repeatedly had higher systolic NIBP in the hospital (140.0 ± 14.0) than at home (133.8 ± 14.8, P = .01). Variation in BP after administration of phenylephrine, but not after administration of acepromazine, is related to the change in splenic volume. BP does not change significantly in consecutive days; however, splenic volume does and is reproducible between observers. Blood pressure in horses is higher in hospital than that in home.

One of the indirect approaches to obtain blood pressure (BP) values is through the so-called pulse transit time (PTT) that is the time for the cardiac wave to propagate through a length of the arterial tree or between the heart and a peripheral arterial site. In this work, we investigated the performance of four latest cuffless BP estimation methods including the method proposed in our previous work by using the invasive BP as reference. The invasive BP data was collected from 10 patients during surgery. Experimental results showed that the estimation errors from the compared methods are much larger than the 5 ± 8 mmHg limits that is required for any BP measurement method or instrument to be satisfied the requirements of the AAMI Standard. Therefore, the PTT-based BP estimation methods need to be further improved and enhanced for obtaining acceptable performance.

Background The availability of an accurate continuous cuffless blood pressure (BP) monitor would provide an alternative to both invasive continuous BP and 24-h intermittent cuff-based BP monitors. We investigated the accuracy of a cuffless beat to beat (BtB) device compared to both invasive BP (iBP) and brachial cuff BP (cBP) measurements. Methods Patients undergoing clinically indicated coronary angiography (CA) and/or percutaneous coronary intervention (PCI) were recruited. After calibration to an initial cBP reading, BP was measured simultaneously using a BtB device (SOMNOtouch NIBP), brachial artery iBP, and cBP at two time points. Results The study was terminated early due to a significant bias. Recordings from 14 participants (11 males, mean age 68.4 years) were analysed. Readings from BtB BP were higher than iBP. The bias between BtB BP and iBP was 34.3 mmHg (95%CI: 27.0, 41.5) and 23.6 mmHg (95%CI: 16.8, 30.4) for SBP and DBP respectively. A similar bias was seen between BtB BP and cBP, but cBP and iBP were largely in agreement. Conclusions In patients undergoing CA/PCI, significant differences were detected between BtB BP and both invasively measured and cuff BP. The non-invasive BtB BP measurement device tested is not suitable for clinical or research use.

Arterial blood pressure (BP) can be measured directly using an invasive intra-arterial method. This method is considered a gold standard, however it is potentially hazardous and requires expensive equipment and professional skills. Therefore, two non-invasive methods-Doppler ultrasonic sphygmomanometry and oscillometry-have been introduced in veterinary medicine. Their accuracy has so far been reliably evaluated in various animal species, however only one study included a small group of goats. Therefore, we carried out a large-scale study which aimed to evaluate agreement between the two non-invasive methods and invasive intra-arterial BP measurement in anesthetized goats at various age. The study included 122 goats of two Polish local breeds (Polish White Improved and Polish Fawn Improved): 67 adult females, 35 adult males, and 20 two-month-old female kids. Goats were anesthetized with the intravenous mixture of xylazine and ketamine. BP was measured simultaneously with the three methods in each goat with 7 measurements on average taken. The study showed that according to the criteria of the American College of Veterinary Internal Medicine (ACVIM) oscillometric method yielded BP measurements sufficiently consistent with invasive intra-arterial method in anesthetized adult goats- 95% of oscillometric BP measurements were expected to differ from invasive BP measurements by at most ±20-25 mmHg. The agreement was worse in goat kids-oscillometry significantly overestimated invasive BP measurements, which resulted in highly asymmetrical 95% limits of agreement. Doppler systolic BP very poorly conformed to invasive systolic BP both in adult goats and in kids and all the ACVIM criteria were violated. Concluding, oscillometry, but not Doppler ultrasonic sphygmomanometry, may be regarded as an alternative to invasive BP measurement in large-scale scientific studies involving adult goats, however, individual oscillometric BP measurements should be treated with caution as estimated 95% limits of agreement were wide.

Mechanical alternans (MA) is a biomarker associated with mortality in heart failure patients. Its detection through continuous blood pressure (BP) monitoring is costly and impractical. In this work, we propose the use of photoplethysmography (PPG) as a non-invasive solution for MA detection. Continuous invasive BP and PPG were recorded and analyzed during ventricular pacing in 10 patients. The presence of MA was evaluated in BP and in features characterizing the PPG pulse morphology. Mechanical alternans was defined as an alternation in maximum dP/dt for a duration of 20 consecutive heart beats or more. Mechanical alternans was observed in BP in 5 patients (50%). The PPG-based MA surrogates showing the highest detection accuracy, were the maximum of the first derivative of the PPG pulse (V' M ), and the pulse amplitude (A). Both features allow detection of MA positive patients with 100% sensitivity and 100% specificity. The magnitude of MA was correlated between BP and V' M PPG (R=0.92, p

The significance of arterial hypertension (AH) is discussed as the main predictor of cardiovascular catastrophes development — myocardial infarction and stroke, and technologies for the solution of blood pressure (BP) control. The most modern world developments are presented for the distant observation of cardiovascular system (CVS) condition, including BP level in high risk patients. The main specifications of abroad invasive BP systems are provided, and Russian developing system with a layout of BP sensor and the method of no wired signal transmission and electrical supply. It is presupposed that such invasive device can in real time mode send the data on BP and its values, that characterize CVS condition. In critical BP changes the signals of alarm are incorporated to send to the emergency care stations and to the physician for proper solutions on the care, including urgencies. Such system might increase the effectiveness of prophylactic and medical care for the patients with cardiovascular pathology, increase the duration of life, and decrease funding, and not need supplementary inclusion of higher qualified specialists for dispensary screening.

Accumulating evidence indicates that central blood pressure (CBP) is a better cardiovascular risk predictor than brachial blood pressure (BP). Although more additional benefits of CBP-based treatment above usual hypertension treatment are to be demonstrated, the demand for implementing CBP assessment in general clinical practice is increasing. For this, the measurement procedure must be noninvasive, easy to perform, and cost- and time-efficient. Therefore, oscillometric devices with the possibility to assess CBP seem the best option. Recently, such an oscillometric BP monitor, the Microlife WatchBP Office Central, was developed, which demonstrated its high accuracy in a validation study against invasive BP measurement. Calibration errors of this device are limited because the procedure is automated, standardized, and performed at the same place of and within 30 s from pulse wave assessment. The transformation from the peripheral pulse wave to CBP is done by means of an individual-based pulse wave analysis according to a theory of arterial compliance and wave reflections. In addition, the device has demonstrated to enable a more reliable diagnosis of hypertension by CBP than by peripheral BP, with a lower frequency of over- and underdiagnosis. Altogether, the available clinical evidence suggests that the Microlife WatchBP Office Central fulfills the criteria for general clinical use.

Limited information exists concerning arterial blood pressure (BP) changes in underwater breath-hold diving. Simulated chamber dives to 50 m of freshwater (mfw) reported very high levels of invasive BP in two divers during static apnea (SA), whereas a recent study using a noninvasive subaquatic sphygmomanometer reported unchanged or mildly increased values at 10 m SA dive. In this study we investigated underwater BP changes during not only SA but, for the first time, dynamic apnea (DA) and shortened (SHT) DA in 16 trained breath-hold divers. Measurements included BP (subaquatic sphygmomanometer), ECG, and pulse oxymetry (arterial oxygen saturation, SpO2, and heart rate). BP was measured during dry conditions, at surface fully immersed (SA), and at 2 mfw (DA and SHT DA), whereas ECG and pulse oxymetry were measured continuously. We have found significantly higher mean arterial pressure (MAP) values in SA (∼40%) vs. SHT DA (∼30%). Postapneic recovery of BP was slightly slower after SHT DA. Significantly higher BP gain (mmHg/duration of apnea in s) was found in SHT DA vs. SA. Furthermore, DA attempts resulted in faster desaturation vs. SA. In conclusion, we have found moderate increases in BP during SA, DA, and SHT DA. These cardiovascular changes during immersed SA and DA are in agreement with those reported for dry SA and DA.

The Vasotrac monitor provides non-invasive near-continuous blood pressure monitoring and is designed to be an alternative to direct intra-arterial blood pressure (BP) measurement. As compared to radial artery invasive BP and upper arm noninvasive BP, Vasotrac readings have been found to have a good agreement with them. However, discrepancies have been reported when rapid changes in BP exist. In the present study we compared BP measured by the Vasotrac monitor on the radial artery with that recorded on the finger arteries by the differential oscillometric device allowing measurement on the beat-to-beat basis. Comparisons were performed on the mean arterial pressure (MAP) level. Special attention was paid to the signal conditioning before comparison of pressures of different temporal resolution. Altogether 383 paired MAP measurements were made in 14 healthy subjects. Based on all 383 paired measurements, the MAP values measured at the radial artery at rest were 4.8±6.0 mm Hg higher than those measured on fingers. The observed difference between the Vasotrac and differential oscillometric device can be explained by different measurement sites. This result is consistent with previous investigations, and the Vasotrac monitor can be considered to adequately track relatively rapid MAP changes on the radial artery. Attention should be paid to a proper signal conditioning before comparison of results obtained by different devices.

BACKGROUND End-stage renal disease (ESRD) is complicated by high blood pressure (BP) and severe atherosclerosis, which may lead to different values of BP measured by invasive and noninvasive methods. However, the differences in BP values between these two methods and their possible mechanisms in ESRD have not been investigated. METHODS Forty-one ESRD patients on dialysis were enrolled in the present study. Invasive BP, noninvasive BP, and carotid hemodynamic variables were obtained through radial artery catheterization, oscillometric methods, and echoarteriography, respectively. RESULTS We found that noninvasive systolic BP (NISBP) was 30±20 mmHg (P

The Philips Intellivue MP50 monitor provides a method for non-invasive, near-continuous blood pressure (BP) monitoring and is designed to be an alternative to direct intra-arterial BP (IABP) measurement. However, no studies have specifically compared non-invasive and invasive BP measurements using the monitor. The present retrospective study observed 515 patients undergoing surgery with general anesthesia, whose invasive (intra-radial, femoral or dorsalis pedis artery) and non-invasive (oscillometric) BP (NIBP) were monitored simultaneously using the monitor. These data were analyzed using correlations, regressions and Bland-Altman plots. The patients were placed in a supine position during surgery. The correlation data for invasive BP and NIBP measurements were: for intra-radial measurements, r2=0.51 (bias and precision, 11.04±15.22 and 14.76±11.64 mmHg, respectively) for systolic BP (SBP) and r2=0.27 (6.17±11.95 and 9.77±9.25 mmHg, respectively) for diastolic BP (DBP); for intra-femoral measurements: r2=0.57 (14.79±14.55 and 17.15±11.68 mmHg, respectively) for SBP and r2=0.45 (4.12±9.70 and 7.49±7.40 mmHg, respectively) for DBP; and for intra-dorsalis pedis measurements: r2=0.33 (13.00±16.81 and 17.34±12.28 mmHg, respectively) for SBP and r2=0.30 (0.17±11.27 and 8.44±7.46 mmHg, respectively) for DBP. According to this data, the NIBP measured by the Philips Intellivue MP50 monitor showed low positive correlations and poor agreement with the IABP, as calculated by Bland-Altman analysis. Therefore, the use of oscillometric BP measured by the monitor in surgery patients under general anesthesia is not generally recommended.

The T-Line TL-200 (Tensys Medical Inc., San Diego, CA, USA) is a noninvasive arterial blood pressure (BP) monitoring system allowing continuous beat-to-beat monitoring of systolic arterial pressure (SAP), mean arterial pressure (MAP), and diastolic arterial pressure (DAP). It provides a real-time BP waveform like that obtained using an arterial catheter for BP monitoring. The aim of this study was to compare BP measurements obtained using the T-Line TL-200 system with simultaneous invasive BP measurements using a femoral arterial catheter in unselected critically ill medical patients.

Arterial blood pressure (BP) measurements, which include invasive direct methods and noninvasive indirect methods, provide a picture of the hemodynamic status of the patient. Invasive BP methods measure pressure pulse wave amplitude; noninvasive methods rely on blood flow or arterial wall motion as a basis for the determination of BP values. To obtain the most accurate BP value, the clinician must identify which measurement variables in a specific clinical situation are most contributory to error and, if possible, use a method of measurement for which the sources of error are not parallel. Blood pressure values obtained by different methods cannot be compared without a thorough understanding of the user-related and instrumentation-related limitations associated with each BP measurement technique

Background Several publications have shown poor outcomes for GETA patients undergoing endovascular stroke interventions. Our goal was to examine the factors directly related to GETA that may impact procedural outcomes. Our hypothesis being that GETA patients are sicker, the procedure may take longer and there may be fluctuations in blood pressure. Methodology An IRB approved retrospective analysis was performed on patients that had undergone stroke interventions over the last 5-years and for whom anesthesia records were available. Blood pressure parameters and time intervals were recorded at multiple steps during a patient’s progress from the ER to the ICU. Patient demographic information and comorbidities were also recorded, as was 90-day clinical outcome. Results Out of 190 patients, GETA was administered in 108(56.8%) and non-GETA in 82(43.2%) patients. The mean age was 67.9(±16.2) years in the GETA and 67.1(±17) years in the non-GETA-group (p = 0.7). The mean NIHSS was 18.9(±8.7) in the GETA versus 13.4(6.8) in the non-GETA-group (p Conclusion GETA was associated with worse outcomes and higher mortality, however, GETA patients had also presented with worse deficits and by itself was not an independent predictor of outcome when NIHSS, age and recanalization were taken into account. A significantly higher BP fluctuation was seen in GETA versus non-GETA groups and a higher difference in pre and post-induction SBP portended a poor outcome amongst the GETA-group. Lastly the interval between arrival and groin puncture was significantly longer in GETA patients. At times GETA may be a necessity in sick patients, however, by strictly controlling BP and introducing measures to reduce delay in procedure start time (such as invasive BP monitoring through the femoral sheath), the “adverse” effect of GETA may be countered in endovascular stroke interventions. Disclosures A. Rai: 2; C; Stryker Neurovascular, Codman Neuro. S. Boo: None. J. Domico: None. T. Roberts: None. J. Carpenter: None.

Introduction Electroencephalographic activity may be influenced by several factors including the gestation of the infant, blood pressure (BP) and inotropic support.1 However, previous studies have used a mixture of invasive and non-invasive BP measurements. We hypothesised that increasing BP and gestation is associated with increased electroencephalographic activity. Methods Infants born Results In 18 subjects, mean (range) gestation and birth weight were 25.4 (23–28) weeks and 756 (515–1070) grams respectively. At most time points after 12 h BP was positively associated with aEEG activity with a stronger association than gestation. At 0–12 h, babies on inotropes had significantly lower aEEG activity (p = 0.013), with no evidence of gestation or BP having an effect. Conclusions There was an association between continuously measured invasive BP and aEEG activity at most time points. However, at 0–12 h we found aEEG activity was lower in babies receiving inotropic support. Reference Shah D, Paradisis M, Bowen JR. Relationship between systemic blood flow, blood pressure, inotropes, and aEEG in the first 48 h of life in extremely preterm infants. Pediatric Research 2013

Objectives To explore the influence of relation between cuff size and arm circumference on accuracy of blood pressure (BP) measurement. Methods 300 patients needed for invasive arterial manometry were enrolled. Before operation, invasive and non-invasive BP were measured three times, and got mean BP. Height, weight, upper arm circumference(UAC) were measured, and to calculate body mass index (BMI), mean BP (MBP). Results The mean UAC was (28.8±3.9 cm) in these 300 patients, and 71.3% patients in this cohort of subjects have UAC greater than 27 cm. Invasive BP measured were higher than those by ordinary cuff non-invasive measurement. With increasing UAC, non-invasive BP readings increased by ordinary cuff, and the difference to invasive BP was greater. Conclusions Using appropriate cuff-bladder can reduce the pseudo-hypertension incidence in blood pressure measurement.