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The incidence of aortic valve stenosis (AoS) increases with age, and once diagnosed, symptomatic severe AoS has a yearly mortality rate of 25%. AoS is diagnosed with transthoracic echocardiography (TTE), however, this gold standard is time consuming and operator and acoustic window dependent. As AoS affects the arterial blood pressure waveform, AoS-specific waveform features might serve as a diagnostic tool. Aim of the present study was to develop a novel, non-invasive, AoS detection model based on blood pressures waveforms. This cross-sectional study included patients with AoS undergoing elective transcatheter or surgical aortic valve replacement. AoS was determined using TTE, and patients with no or mild AoS were labelled as patients without AoS, while patients with moderate or severe AoS were labelled as patients with AoS. Non-invasive blood pressure measurements were performed in awake patients. Ten minutes of consecutive data was collected. Several blood pressure-based features were derived, and the median, interquartile range, variance, and the 1st and 9th decile of the change of these features were calculated. The primary outcome was the development of a machine-learning model for AoS detection, investigating multiple classifiers and training on the area under the receiver-operating curve (AUROC). In total, 101 patients with AoS and 48 patients without AoS were included. Patients with AoS showed an increase in left ventricular ejection time (0.02 s, p = 0.001), a delayed maximum upstroke in the systolic phase (0.015 s, p < 0.001), and a delayed maximal systolic pressure (0.03 s, p < 0.001) compared to patients without AoS. With the logistic regression model, a sensitivity of 0.81, specificity of 0.67, and AUROC of 0.79 were found. The majority of the population without AoS was male (85%), whereas in the population with AoS this was evenly distributed (54% males). Age was significantly (5 years, p < 0.001) higher in the population with AoS. In the present study, we developed a novel model able to distinguish no to mild AoS from moderate to severe AoS, based on blood pressure features with high accuracy. Clinical registration number: The study entailing patients with TAVR treatment was registered at ClinicalTrials.gov (NCT03088787, https://clinicaltrials.gov/ct2/show/NCT03088787). The study with elective cardiac surgery patients was registered with the Netherland Trial Register (NL7810, https://trialsearch.who.int/Trial2.aspx?TrialID=NL7810). [ABSTRACT FROM AUTHOR]

Abstract Background Oscillometric, non-invasive blood pressure measurement (NIBP) is the first choice of blood pressure monitoring in the majority of low and moderate risk surgeries. In patients with morbid obesity, however, it is subject to several limitations. The aim was to compare arterial pressure monitoring by NIBP and a non-invasive finger-cuff technology (Nexfin®) with the gold-standard invasive arterial pressure (IAP). Methods In this secondary analysis of a prospective observational, single centre cohort study, systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP) were measured at 16 defined perioperative time points including posture changes, fluid bolus administration and pneumoperitoneum (PP) in patients undergoing laparoscopic bariatric surgery. Absolute arterial pressures by NIBP, Nexfin® and IAP were compared using correlation and Bland Altman analyses. Interchangeability was defined by a mean difference ≤ 5 mmHg (SD ≤8 mmHg). Percentage error (PE) was calculated as an additional statistical estimate. For hemodynamic trending, concordance rates were analysed according to the Critchley criterion. Results Sixty patients (mean body mass index of 49.2 kg/m2) were enrolled and data from 56 finally analysed. Pooled blood pressure values of all time points showed a significant positive correlation for both NIPB and Nexfin® versus IAP. Pooled PE for NIBP versus IAP was 37% (SAP), 35% (DAP) and 30% (MAP), for Nexfin versus IAP 23% (SAP), 26% (DAP) and 22% (MAP). Correlation of MAP was best and PE lowest before induction of anesthesia for NIBP versus IAP (r = 0.72; PE 24%) and after intraoperative fluid bolus administration for Nexfin® versus IAP (r = 0.88; PE: 17.2%). Concordance of MAP trending was 90% (SAP 85%, DAP 89%) for NIBP and 91% (SAP 90%, DAP 86%) for Nexfin®. MAP trending was best during intraoperative ATP positioning for NIBP (97%) and at induction of anesthesia for Nexfin® (97%). Conclusion As compared with IAP, interchangeability of absolute pressure values could neither be shown for NIBP nor Nexfin®, however, NIBP showed poorer overall correlation and precision. Overall trending ability was generally high with Nexfin® surpassing NIBP. Nexfin® may likely render individualized decision-making in the management of different hemodynamic stresses during laparoscopic bariatric surgery, particularly where NIBP cannot be reliably established. Trial registration The non-interventional, observational study was registered retrospectively at ( NCT03184285 ) on June 12, 2017.

Purpose: Altered gravity environments introduce cardiovascular changes that may require continuous hemodynamic monitoring in both spaceflight and terrestrial analogs. Conditions in such environments are often prohibitive to direct/invasive methods and therefore, indirect measurement techniques must be used. This study compares two common cardiac measurement techniques used in the human spaceflight domain, pulse contour analysis (PCA—Nexfin) and inert gas rebreathing (IGR—Innocor), in subjects completing ergometer exercise under altered gravity conditions simulated using a tilt paradigm. Methods: Seven subjects were tilted to three different angles representing Martian, Lunar, and microgravity conditions in the rostrocaudal direction. They completed a 36-min submaximal cardiovascular exercise protocol in each condition. Hemodynamics were continuously monitored using Nexfin and Innocor. Results: Linear mixed-effects models revealed a significant bias of 25.7 ± 1.7 ml ( p < 0.0001 ) in stroke volume and 3.19 ± 0.18 l/min ( p < 0.0001 ) in cardiac output, with Nexfin measuring greater than Innocor in both variables. These values are in agreement with a Bland-Altman analysis. The correlation of stroke volume and cardiac output measurements between Nexfin and Innocor were r = 0.54 ( p < 0.0001 ) and r = 0.76 ( p < 0.0001 ) respectively. Conclusion: There is a poor agreement in absolute stroke volume and cardiac output values between measurement via PCA (Nexfin) and IGR (Innocor) in subjects who are exercising in simulated altered gravity environments. These results suggest that the chosen measurement method and device greatly impacts absolute measurements of cardiac output. However, there is a good level of agreement between the two devices when measuring relative changes. Either of these devices seem adequate to capture cardiac changes, but should not be solely relied upon for accurate measurement of absolute cardiac output. [ABSTRACT FROM AUTHOR]

Objective: In this study we compared noninvasive arterial pressure measurement using ClearSight™ vascular-unloading-technique (Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurement during induction of anesthesia undergoing mayor cardiac surgery. Design: Prospective, monocentric. Setting: University hospital. Participants: 54 patients undergoing mayor cardiac surgery. Interventions: During induction all patients were simultaneously monitored with invasive (reference method) and noninvasive arterial pressure measurement (test-method) over a mean time period of 27 minutes. Measurements and Main Results: We observed slightly lower systolic and mean arterial pressures noninvasive than invasive. For systolic arterial pressure the mean of the differences was -18,05 mmHg (p < 0,05, SD ±16,78 mmHg), the mean arterial pressure MAP -5,47 mmHg (p < 0,05, SD ±11,08 mmHg) and for diastolic pressure -1,09 mmHg (p < 0,05, SD±11,15 mmHg),. The mean of the differences in heartrate was 1,15 (p < 0,05, SD±6,9 mmHg). When considering all measured values of the invasively measured MAP and the ClearSight ™ -MAP at the same timestamp over the recording interval, an almost identical progress can be seen that indicates a sufficient mapping of the hemodynamic changes. The percentage error for mean arterial, systolic and diastolic pressure measured by ClearSight™ amounts to 25,95 %, 26,77 % and 34,16 %, respectively. Conclusions: We conclude that ClearSight ™ is a good option for hemodynamic monitoring during induction of anesthesia. Taking into account the limitations, non-invasive arterial blood pressure measurement offers sufficient security to safely initiate anesthesia, especially when MAP is of particular interest. The use of non-invasive arterial blood pressure measurement with ClearSight ™ during induction of anesthesia in patients scheduled for major cardiac surgery is reliable and easy to use.

Background: Oscillometric, non-invasive blood pressure measurement (NIBP) is the first choice of blood pressure monitoring in the majority of low and moderate risk surgeries. In patients with morbid obesity, however, it is subject to several limitations. The aim was to compare arterial pressure monitoring by NIBP and a non-invasive finger-cuff technology (Nexfin®) with the gold-standard invasive arterial pressure (IAP). Methods: In this secondary analysis of a prospective observational, single centre cohort study, systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP) were measured at 16 defined perioperative time points including posture changes, fluid bolus administration and pneumoperitoneum (PP) in patients undergoing laparoscopic bariatric surgery. Absolute arterial pressures by NIBP, Nexfin® and IAP were compared using correlation and Bland Altman analyses. Interchangeability was defined by a mean difference ≤ 5 mmHg (SD ≤8 mmHg). Percentage error (PE) was calculated as an additional statistical estimate. For hemodynamic trending, concordance rates were analysed according to the Critchley criterion. Results: Sixty patients (mean body mass index of 49.2 kg/m2) were enrolled and data from 56 finally analysed. Pooled blood pressure values of all time points showed a significant positive correlation for both NIPB and Nexfin® versus IAP. Pooled PE for NIBP versus IAP was 37% (SAP), 35% (DAP) and 30% (MAP), for Nexfin versus IAP 23% (SAP), 26% (DAP) and 22% (MAP). Correlation of MAP was best and PE lowest before induction of anesthesia for NIBP versus IAP (r = 0.72; PE 24%) and after intraoperative fluid bolus administration for Nexfin® versus IAP (r = 0.88; PE: 17.2%). Concordance of MAP trending was 90% (SAP 85%, DAP 89%) for NIBP and 91% (SAP 90%, DAP 86%) for Nexfin®. MAP trending was best during intraoperative ATP positioning for NIBP (97%) and at induction of anesthesia for Nexfin® (97%). Conclusion: As compared with IAP, interchangeability of absolute pressure values could neither be shown for NIBP nor Nexfin®, however, NIBP showed poorer overall correlation and precision. Overall trending ability was generally high with Nexfin® surpassing NIBP. Nexfin® may likely render individualized decision-making in the management of different hemodynamic stresses during laparoscopic bariatric surgery, particularly where NIBP cannot be reliably established. Trial registration: The non-interventional, observational study was registered retrospectively at (NCT03184285) on June 12, 2017. [ABSTRACT FROM AUTHOR]

Pulse pressure variation (PPV) is a dynamic cardiac preload variable used to predict fluid responsiveness. PPV can be measured non-invasively using innovative finger-cuff systems allowing for continuous arterial pressure waveform recording, e.g., the Nexfin system [BMEYE B.V., Amsterdam, The Netherlands; now Clearsight (Edwards Lifesciences, Irvine, CA, USA)] (PPVFinger). However, the agreement between PPVFinger and PPV derived from an arterial catheter (PPVART) in obese patients having laparoscopic bariatric surgery is unknown. We compared PPVFinger and PPVART at 6 time points in 60 obese patients having laparoscopic bariatric surgery in a secondary analysis of a prospective method comparison study. We used Bland-Altman analysis to assess absolute agreement between PPVFinger and PPVART. The predictive agreement for fluid responsiveness between PPVFinger and PPVART was evaluated across three PPV categories (PPV < 9%, PPV 9-13%, PPV > 13%) as concordance rate of paired measurements and Cohen's kappa. The overall mean of the differences between PPVFinger and PPVART was 0.5 ± 4.6% (95%-LoA - 8.6 to 9.6%) and the overall predictive agreement was 72.4% with a Cohen's kappa of 0.53. The mean of the differences was - 0.7 ± 3.8% (95%-LoA - 8.1 to 6.7%) without pneumoperitoneum in horizontal position and 1.1 ± 4.8% (95%-LoA - 8.4 to 10.5%) during pneumoperitoneum in reverse-Trendelenburg position. The absolute agreement and predictive agreement between PPVFinger and PPVART are moderate in obese patients having laparoscopic bariatric surgery. [ABSTRACT FROM AUTHOR]

Objective: In this study we compared noninvasive arterial pressure measurement using ClearSight™ vascular-unloading-technique (Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurement during induction of anesthesia undergoing mayor cardiac surgery.Design: Prospective, monocentric.Setting: University hospital.Participants: 54 patients undergoing mayor cardiac surgery.Interventions: During induction all patients were simultaneously monitored with invasive (reference method) and noninvasive arterial pressure measurement (test-method) over a mean time period of 27 minutes.Measurements and Main Results: We observed slightly lower systolic and mean arterial pressures noninvasive than invasive. For systolic arterial pressure the mean of the differences was -18,05 mmHg (p < 0,05, SD ±16,78 mmHg), the mean arterial pressure MAP -5,47 mmHg (p < 0,05, SD ±11,08 mmHg) and for diastolic pressure -1,09 mmHg (p < 0,05, SD±11,15 mmHg),. The mean of the differences in heartrate was 1,15 (p < 0,05, SD±6,9 mmHg). When considering all measured values of the invasively measured MAP and the ClearSight ™ -MAP at the same timestamp over the recording interval, an almost identical progress can be seen that indicates a sufficient mapping of the hemodynamic changes. The percentage error for mean arterial, systolic and diastolic pressure measured by ClearSight™ amounts to 25,95 %, 26,77 % and 34,16 %, respectively.Conclusions: We conclude that ClearSight ™ is a good option for hemodynamic monitoring during induction of anesthesia. Taking into account the limitations, non-invasive arterial blood pressure measurement offers sufficient security to safely initiate anesthesia, especially when MAP is of particular interest. The use of non-invasive arterial blood pressure measurement with ClearSight ™ during induction of anesthesia in patients scheduled for major cardiac surgery is reliable and easy to use. [ABSTRACT FROM AUTHOR]

Background: Compared to healthy individuals, obese have significantly higher systolic and diastolic blood pressure, mean arterial pressure, heart rate, and cardiac output. The aim of this study was to evaluate cardiovascular hemodynamic changes before and 3 months after bariatric surgery. Methods: Patients scheduled for bariatric surgery between the 29th of September 2016 and 24th of March 2016 were included and compared with 24 healthy individuals. Hemodynamic measurements were performed preoperatively and 3 months after surgery, using the Nexfin® non-invasive continuous hemodynamic monitoring device (Edwards Lifesciences/BMEYE B.V., Amsterdam, the Netherlands). Results: Eighty subjects were included in this study, respectively, 56 obese patients scheduled for bariatric surgery and 24 healthy individuals. Baseline hemodynamic measurements showed significant differences in cardiac output (6.5 ± 1.6 versus 5.7 ± 1.6 l/min, p = 0.046), mean arterial pressure (107 ± 19 versus 89 ± 11 mmHg, p = 0.001), systolic (134 ± 24 versus 116 ± 18 mmHg, p = 0.001) and diastolic blood pressure (89 ± 17 versus 74 ± 10 mmHg, p = 0.001), and heart rate (87 ± 12 versus 76 ± 14 bpm, p = 0.02) between obese and healthy subjects. Three months after surgery, significant changes occurred in mean arterial pressure (89 ± 17 mmHg, p = 0.001), systolic (117 ± 24 mmHg, p = 0.001) and diastolic blood pressure (71 ± 15 mmHg, p = 0.001), stroke volume (82.2 ± 22.4 ml, p = 0.03), and heart rate (79 ± 17 bpm, p = 0.02) Conclusions: Three months after bariatric surgery, significant improvements occur in hemodynamic variables except cardiac output and cardiac index, in the patient group. [ABSTRACT FROM AUTHOR]

Study Objective: The present study aimed to validate the Nexfin® monitor and to assess the accuracy compared to classical sphygmomanometry (Riva-Rocci/Korotkoff (RRK)) blood pressure (BP) measurements in patients with obesity scheduled for bariatric surgery.Design: Validation study.Setting: Outpatient clinic for bariatric surgery.Patients: 33 patients scheduled for bariatric surgery.Measurements: The validation process was done according to the protocols developed by the European Society of Hypertension from 2010. The Nexfin® monitor (Edwards Lifesciences/BMEYE B.V., Amsterdam, The Netherlands) calculates beat-to-beat blood pressure from finger pulse wave analysis. Measurements of systolic and diastolic BP were obtained using classical sphygmomanometry and the Nexfin® alternatingly.Main Results: In total 99 pairs of BP measurements were used. The device failed pass phase 1 as 65 systolic readings fell within 5mmHg (73 required). And 61, 76 and 90 diastolic readings fell within 5, 10 and 15mmHg respectively. Finally, it failed to pass phase 2 as 23 patients for systolic and 25 for diastolic had at least 2/3 of their comparisons falling within 5mmHg (24 required) but 10 subjects for systolic and 8 for diastolic had all three comparisons more than 5mmHg different from the RRK readings (zero allowed). Mean differences were 7.8±6.9mmHg for SBP and 8.0±7.2mmHg for DBP.Conclusion: Using the revised protocol, the Nexfin® device was not able to pass validation. However using the original protocol, the Nexfin® device passed phase 1 and 2.1 of the validation process and failed to pass phase 2.2. [ABSTRACT FROM AUTHOR]

Background: Patients undergoing carotid endarterectomy require strict arterial blood pressure (BP) control to maintain adequate cerebral perfusion. In this study we tested whether non-invasive beat-to-beat Nexfin finger BP (BPfin) can replace invasive beat-to-beat radial artery BP (BPrad) in this setting.Methods: In 25 consecutive patients (median age 71 yr) scheduled for carotid endarterectomy and receiving general anaesthesia, BPfin and BPrad were monitored simultaneously and ipsilaterally during the 30-min period surrounding carotid artery cross-clamping. Validation was guided by the standard set by the Association for the Advancement of Medical Instrumentation (AAMI), which considers a BP monitor adequate when bias (precision) is <5 (8) mm Hg, respectively.Results: BPfin vs BPrad bias (precision) was -3.3 (10.8), 6.1 (5.7) and 3.5 (5.2) mm Hg for systolic, diastolic, and mean BP, respectively. One subject was excluded due to a poor quality BP curve. In another subject, mean BPfin overestimated mean BPrad by 13.5 mm Hg.Conclusion: Mean BPfin could be considered as an alternative for mean BPrad during a carotid endarterectomy, based on the AAMI criteria. In 23 of 24 patients, the use of mean BPfin would not lead to decisions to adjust mean BPrad values outside the predefined BP threshold.Clinicaltrialsgov: NCT01451294. [ABSTRACT FROM AUTHOR]

Physiological calibration (Physiocal) improves the quality of continuous blood pressure (BP) signal from finger. However, the effects of Physiocal on spectral characteristics of systolic BP (SBP) variability are not well-known. We tested the hypothesis that the use of Physiocal may alter the results on SBP variability when compared with BP recording without Physiocal. Continuous BP was recorded simultaneously from fingers of both arms during 10-min standing by two Nexfin devices, one with (ON) and the other without (OFF) Physiocal (n=19). Missing SBP values in ON signal were linearly interpolated over Physiocal sequences (ON_inter). The OFF signal was analyzed without any corrections (OFF_reference) and after linear interpolation of corresponding sequences when Physiocal appeared in the ON signal (OFF_inter). Mean low frequency power of SBP oscillations (LF_SBP, 0.04-0.15 Hz) did not differ between the OFF_reference, OFF_inter and ON_inter. However, LF_SBP deviated more from OFF_reference when analysed from ON_inter compared with the analysis from OFF_inter (median [interquartile range]: 14.7 [4.6-38.6] vs. 0.9 [0.5-1.8] %, p

Physiological calibration (Physiocal) improves the quality of continuous blood pressure (BP) signal from finger. However, the effects of Physiocal on spectral characteristics of systolic BP (SBP) variability are not well-known. We tested the hypothesis that the use of Physiocal may alter the results on SBP variability when compared with BP recording without Physiocal. Continuous BP was recorded simultaneously from fingers of both arms during 10-min standing by two Nexfin devices, one with (ON) and the other without (OFF) Physiocal (n = 19). Missing SBP values in ON signal were linearly interpolated over Physiocal sequences (ONinter). The OFF signal was analyzed without any corrections (OFFreference) and after linear interpolation of corresponding sequences when Physiocal appeared in the ON signal (OFFinter). Mean low frequency power of SBP oscillations (LFSBP, 0.04-0.15 Hz) did not differ between the OFFreference, OFFinter, and ONinter. However, LFSBP deviated more from OFFreference when analyzed from ONinter compared with the analysis from OFFinter [median (interquartile range): 14.7 (4.6-38.6) vs. 0.9 (0.5-1.8) %, p < 0.05]. In conclusion, the use of Physiocal had a significant effect on the spectral SBP variability that overwhelms the impact of linear interpolation of short data sequences. Therefore, caution is needed when comparing SBP variability between BP datasets acquired with and without Physiocal. [ABSTRACT FROM AUTHOR]

Background For a majority of patients undergoing anaesthesia for general surgery, mean arterial pressure (MAP) is only measured intermittently by arm cuff oscillometry (MAPiNIAP). In contrast, the Nexfin® device provides continuous non-invasive measurement of MAP (MAPcNIAP) using a finger cuff. We explored the agreement of MAPcNIAP and MAPiNIAP with the gold standard: continuous invasive MAP measurement by placement of a radial artery catheter (MAPinvasive). Methods In a total of 120 patients undergoing elective general surgery and clinically requiring MAPinvasive measurement, MAPiNIAP and MAPcNIAP were measured in a 30 min time period at an arbitrary moment during surgery with stable haemodynamics. MAPiNIAP was measured every 5 min. Results Data from 112 patients were analysed. Compared with MAPinvasive, modified Bland–Altman analysis revealed a bias (sd) of 2 (9) mm Hg for MAPcNIAP and −2 (12) mm Hg for MAPiNIAP. Percentage errors for MAPcNIAP and MAPiNIAP were 22% and 32%, respectively. Conclusions In a haemodynamically stable phase in patients undergoing general anaesthesia, the agreement with invasive MAP of continuous non-invasive measurement using a finger cuff was not inferior to the agreement of intermittent arm cuff oscillometry. Continuous measurements using a finger cuff can interchangeably be used as an alternative for intermittent arm cuff oscillometry in haemodynamically stable patients, with the advantage of beat-to-beat haemodynamic monitoring. Clinical trial registration NCT 01362335 (clinicaltrials.gov). [ABSTRACT FROM PUBLISHER]

Objective: The aim of the present study was to compare 2 noninvasive cardiac output measurement methods with the continuous cardiac output thermodilution (CCO-TD) method. Design: A single-center prospective design. Setting: A university hospital. Participants: Fifty-three consecutive patients scheduled for elective, non-emergent cardiac surgery. Interventions: With each participant the cardiac output was measured using 3 methods: CCO-TD, the Endotracheal Cardiac Output Monitor (ECOM), and the Nexfin monitor. Measurements and Main Results: Measurements were performed simultaneously at 7 time points: After induction, before cardiopulmonary bypass, after cardiopulmonary bypass, after protamine, after arrival in the intensive care unit, and before extubation on postoperative day 1. Statistical analysis was performed using Pearson’s correlation, Bland-Altman, percent error, and polar plots. Compared to CCO-TD, ECOM showed significant correlation of R0.619 with a bias of -0.13 L/min (95% confidence interval -2.19-1.93 L/min), a percent error of 40%, and trending ability of 87% and 97% within 0.5 L/min and 1.0 L/min, respectively. The Nexfin monitor showed significant correlation of R0.535 with a bias of−0.35 L/min (95% confidence interval−3.36-2.66 L/min), a percent error of 58% and trending ability of 84% and 97% were within 0.5 L/min and 1.0 L/min limits of agreement. Conclusions: Neither the ECOM nor the Nexfin had the ability to replace the thermodilution-based continuous cardiac output monitor. The ECOM did not have acceptable accuracy or trending ability and only could be utilized for intubated patients. The Nexfin lacked reliability and trending ability. Also, the Nexfin did not provide consistent results. [Copyright &y& Elsevier]

Introduction: Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting changes in ABP and CO, we compared FAP to intra-arterially measured blood pressure (ABPIA) and transpulmonary thermodilution (COTD) in postcardiac surgery patients during a fluid challenge (FC). Methods: Twenty sedated patients post cardiac surgerywere included, and 28 FCs were performed.Measurements of ABP and CO were simultaneously collected before and after an FC, and we compared CO and blood pressure. Results: Finger arterial pressure was obtainable in all patients.When comparing ABPNI with ABPIA, biaswas2.7mm Hg (limits of agreement [LOA], ±22.2), 4.9 mm Hg (LOA, ±13.6), and 4.2 mm Hg (LOA, ±13.7) for systolic, diastolic, and mean arterial pressure, respectively. Concordance between changes in ABPNI and ABPIA was 100%. Mean bias between CONI and COTD was -0.26 (LOA, ±2.2), with a percentage error of 38.9%. Concordance between changes in CONI vs COTD and was 100%. Conclusion: Finger arterial pressure reliably measures ABP and adequately tracks changes in ABP. Although CONI is not interchangeable with COTD, it follows changes in CO closely. [ABSTRACT FROM AUTHOR]

The arterial baroreflex regulates blood pressure by modifying heart rate and systemic vascular resistance. Baroreflex sensitivity is expressed as the relation between changes in blood pressure and the resulting changes in reciprocal values of heart rate (cardBRS) and in reciprocal values of vascular resistance (vascBRS). This study investigated determinants of vascBRS and cardBRS and their relationship in a random population sample. Continuous noninvasive arterial pressure was analyzed in 105 adults (43 males) with a median age of 45 (range 18-95) years and body mass index of 24.5 (range 18.1-39.1) kg m. Systolic and diastolic blood pressures were 130 (range 95-205) and 80 (range 47-141) mmHg, and heart rate was 66 (range 42-109) beats min. Pulse contour (CO-trek)-determined vascular resistance was 1.37 (range 0.60-7.75) mmHg s ml. The results of vascBRS and cardBRS were log-transformed; linear regression analysis revealed that age, resistance, systolic and diastolic blood pressures were major determinants of log(vascBRS) explaining 30.5 % of the variance. Determinants of log(cardBRS) were age, body mass index, heart rate, systolic and diastolic blood pressures, explaining 70.4 % of the variance. Thus, some established determinants of cardBRS were not correlated with vascBRS. There was no correlation between log(cardBRS) and log(vascBRS) after correction for age, supporting that vascBRS is an independent description of baroreflex regulation. These findings suggest that vascBRS and cardBRS report different modalities of cardiovascular autonomic function. [ABSTRACT FROM AUTHOR]

Objectives: A growing interest in monitoring cardiac output (CO) noninvasively has emerged; however, its determination has been difficult using the standard approaches. The aim of this study was to evaluate the accuracy and precision of pulse contour analysis (PCA) compared with cardiac magnetic resonance imaging (CMR). Design: A single-center prospective study. Setting: A university hospital. Participants: Thirty-nine consecutive stable patients undergoing CMR. Interventions: CO was determined twice by PCA using the Nexfin monitoring system (BMEYE BV, Amsterdam, The Netherlands). Measurements were performed after 10 minutes of rest in a stable supine position immediately before or after the CMR examination. Measurements and Main Results: There was a mean bias of 0.2 ± 1.9 L/min between CMR and PCA and a reproducibility of 0.2 ± 0.6 L/min for PCA. Between 4.8 and 6.3 L/min (second quartile of COCMR), there was a good agreement (mean bias = −0.2 ± 1.3 L/min). Comparing quartile 1 (−1.3 ± 2.0 L/min) overestimating and quartiles 3 (1.4 ± 0.9 L/min) and 4 (0.9 ± 2.0 L/min) underestimating CO, a statistically significant difference was found. The reproducibility was not affected by the quartile (p = 0.23, analysis of variance), whereas there was a significant difference between the nonoutlier and outlier group when using the Mann-Whitney U test (p = 0.02). Conclusions: Noninvasive PCA allows the safe and economic measurement of CO, yet it still has major limitations. Although the agreement with CMR was acceptable, there was a clinically unacceptable variation; absolute values should not be used interchangeably. These results suggest that therapeutic interventions and clinical decisions should not be based on noninvasive PCA measurements at the present time. [ABSTRACT FROM AUTHOR]

Monitoring of continuous blood pressure and cardiac output is important to prevent hypoperfusion and to guide fluid administration, but only few patients receive such monitoring due to the invasive nature of most of the methods presently available. Noninvasive blood pressure can be determined continuously using finger cuff technology and cardiac output is easily obtained using a pulse contour method. In this way completely noninvasive continuous blood pressure and cardiac output are available for clinical use in all patients that would otherwise not be monitored. Developments and state of art in hemodynamic monitoring are reviewed here, with a focus on noninvasive continuous hemodynamic monitoring form the finger. [ABSTRACT FROM AUTHOR]

Abstract: Study Objective: To evaluate the validity of cardiac output (CO) measurements obtained using the Nexfin device in comparison to those obtained with the esophageal Doppler in steady-state conditions and after phenylephrine administration. Design: Prospective observational study. Setting: Operating room of a North American academic medical center. Patients: 25 ASA physical status 1, 2, and 3 patients referred for abdominal or orthopedic surgeries. Interventions: After endotracheal intubation, patients who presented with a 20% or greater decrease in mean arterial pressure (MAP) received an intravenous (IV) bolus of 100 μg of phenylephrine. If MAP was still 20% lower than the patient''s baseline level at least 10 minutes after the first vasopressor treatment, a second bolus of 100 μg of phenylephrine was given. Measurements: CO was measured simultaneously by esophageal Doppler (COED) and Nexfin (CONXF) at baseline and when blood pressure peaked after an IV 100 μg phenylephrine bolus. Comparisons were then made between the two devices to evaluate the ability of the Nexfin device to track changes in CO. Main Results: 66 pairs of data were obtained. Mean COED and CONXF were 4.7 ± 1.8 L/min and 5.6 ± 2.0 L/min, respectively. There was a significant relationship between COED and CONXF (r2 = 0.82; P < 0.001). The agreement between COED and CONXF was 0.88 ± 0.86 L/min (Bland Altman). The mean percent error (Critchley and Critchley) of CONXF versus COED was 37%. Trending analysis found a 94% concordance between changes in COED and CONXF after phenylephrine administration. Conclusions: Intraoperative CO measurement using the Nexfin device has a strong correlation with CO measured by esophageal Doppler. [Copyright &y& Elsevier]

The Nexfin device allows for non-invasive beat-to-beat blood pressure monitoring (BP). Perioperative hypotension and hypertension have been shown to be associated with poor clinical outcomes. The goal of the present study was to assess the ability of this device to decrease the duration of significant intraoperative hypo- or hypertension compared to standard BP monitoring by cuff (BP). We studied25 patients (ASA I-III) undergoing either abdominal or orthopedic surgery. BP was monitored every 5 min from the introduction of anesthesia, while BP was monitored continuously on the opposite arm. When systolic BP (SBP) decreased or increased more than 20% relative to baseline SBP, a standard BP measurement was taken to compare values. In addition, the time interval between the 20% change in SBP and the next scheduled standard SBP measurement was recorded for each event. The mean length of surgery was 3.0 ± 0.3 h. Patients presented with 11 ± 4 episodes of hypotension and 12 ± 4 episodes of hypertension during the surgery. If BP had been used, this would have resulted in 21 ± 7 min of hypotension and 20 ± 10 min of hypertension. If hemodynamic changes seen by SBP were appropriately treated, an average of 7 ± 1 min/h of hypotension time, 7 ± 2 min/h of hypertension time and 14 ± 3 min per hour of hypo- or hypertension time may have been identified. The Nexfin BP has the potential to decrease the time of hypotension and hypertension compared to conventional intermittent BP monitoring. Therefore, this device has the potential to positively impact clinical outcomes. [ABSTRACT FROM AUTHOR]

Introduction: An impairment of cardiac haemodynamics and fluid retention may occur in patients with acute heart failure (AHF) because of left ventricular (LV) dysfunction due to volume and/or pressure overload. The measurement of B-type natriuretic peptide (BNP) represents the 'gold standard' of biomarker assessment for evaluating LV adaptations to AHF. More recently, Nexfin and bioelectric impedance vector analysis (BIVA) techniques have been proposed for non-invasively assessing haemodynamic and hydration status, respectively. These techniques are rapidly and easily executable and, most importantly, may be repeated over time. Aim: To validate the applicability of Nexfin and BIVA techniques, in association with BNP dosage, and changes of these parameters after treatment during hospitalization in patients with AHF referring to the emergency department (ED). Methods: We enrolled 44 patients (20 female, mean age 77 ± 7.7 years), referring to ED for AHF. During hospitalization (mean ± SD: 4.12 ± 1.45 days), all patients underwent BNP measurements at admission, 24 hours, 72 hours and at discharge. At the same time intervals, Nexfin and BIVA were also performed. According to international guidelines, all patients were treated with optimal pharmacological therapy, independently of other parameters examined during hospitalization. Results: Compared with baseline (747.61 ± 658.54 pg/mL), we observed a statistically significant reduction of BNP levels at 72 hours (357.64 ± 193.81 pg/mL; p < 0.05) and at discharge times (248.57 ± 194.46 pg/mL; p < 0.05). In addition, a significant reduction of hydration status, evaluated through BIVA, was observed at discharge compared with hospital admission (from 79.44 ± 6.47% to 76.35 ± 5.5%; p< 0.05). This was paralleled at Nexfin evaluation by a significant increase of cardiac index (from 2.32 ± 0.95 to 3.9 ± 1.18 L/min/m2) and clinical improvement of New York Heart Association class at discharge compared with hospital admission. Finally, we observed a statistically significant correlation between percentage variation of cardiac index and hydration status from admission to discharge (p < 0.05). Conclusions: In patients with AHF, admitted to ED, simultaneous monitoring of cardiac index and of hydration status by non-invasive methods may be useful for confirming clinical diagnosis, beyond dosages of BNP. These techniques could also be useful for intra-hospital management of AHF patients. In fact, their variations, coupled with the BNP ones, during hospitalization, may be of value in order to easily and rapidly identify clinical and haemodynamic improvements of AHF, which may be of key relevance for appropriate discharges from EDs. [ABSTRACT FROM AUTHOR]

Background: Unfavourable circulatory system conditions have been observed in many patients with spinal anaesthesia. The most frequent symptoms include a decrease in blood pressure and, less frequently, bradycardia. The appearance of unfavourable consequences of spinal anaesthesia might be related to the initial status of the patient's circulatory system. The aim of this study was to establish the possibility of predicting unfavourable circulatory consequences (hypotension, bradycardia) following spinal anaesthesia, based on non-invasive haemodynamic assessment with a Nexfin device., Methods: This prospective study included 100 18-60-year-old ASA I or II planned spinal anaesthesia patients. The initial hemodynamic parameters were assessed with a Nexfin monitor. Anaesthesia was performed with 3-3.5 mL of a 0,5% hyperbaric bupivacaine solution. Within 20 min after the administration of anaesthesia, the arterial blood pressure values, heart rate, sensory blockade level, and motoric blockade level were recorded in 5-min intervals. Hypotension was classified by a decrease of SAP < 90 mm Hg and/or the decrease of the SAP ≥ 20% initial value. Logistic regression was used to determine the independent predictors of hypotension resulting from a spinal blockade., Results: The development of hypotension and bradycardia was observed in 39 and 2%, respectively, of the patients. The patients who developed hypotension differed significantly from those who did not develop this symptom, with the main difference being the body mass and the assessment on the ASA scale. The patients who developed hypotension after spinal anaesthesia differed significantly in the initial hemodynamic parameters (SAP, MAP, SVRI). The following two independent risk factors for hypotension were isolated: the mean arterial pressure (OR 1.04; 95% CI: 1.005-1.076) and the systemic vascular resistance index (OR 1.109; 95% CI: 1.021-1.204)., Conclusions: Nexfin-based non-invasive haemodynamic monitoring might be helpful in the identification of individuals with a high risk of hypotension following spinal blockade.