Effect of intraoperative personalized goal-directed hemodynamic management on acute myocardial injury in high-risk patients having major abdominal surgery: a post-hoc secondary analysis of a randomized clinical trial.

Acute myocardial injury is common after noncardiac surgery and associated with mortality. Impaired intraoperative cardiovascular dynamics are a risk factor for acute myocardial injury. Optimizing intraoperative cardiovascular dynamics may thus reduce acute myocardial injury. We aimed to investigate the effect of intraoperative personalized goal-directed hemodynamic management on the incidence of acute myocardial injury. We hypothesized that personalized goal-directed hemodynamic management reduces the incidence of acute myocardial injury compared to routine hemodynamic management in high-risk patients having major abdominal surgery. We performed a post-hoc secondary analysis of a randomized clinical trial including 180 high-risk major abdominal surgery patients that were randomized to personalized goal-directed hemodynamic management or routine hemodynamic management. We compared the incidences of acute myocardial injury-defined according to the Fourth Universal Definition of Myocardial Infarction (2018)-between patients randomized to personalized goal-directed hemodynamic management or routine hemodynamic management by calculating the relative and absolute risk reduction together with 95% Wald confidence intervals and P values. Acute myocardial injury occurred in 4 of 90 patients (4%) in the personalized goal-directed hemodynamic management group and in 12 of 90 patients (13%) in the routine hemodynamic management group (relative risk: 0.33, 95% confidence interval: 0.11 to 0.99, P = 0.036; absolute risk reduction: - 9%, 95% confidence interval: - 17% to - 0.68%, P = 0.034). In this post-hoc secondary analysis, intraoperative personalized goal-directed hemodynamic management reduced the incidence of acute myocardial injury compared to routine hemodynamic management in high-risk patients having major abdominal surgery. This needs to be confirmed in larger prospective trials.

Continuous noninvasive pulse wave analysis using finger cuff technologies for arterial blood pressure and cardiac output monitoring in perioperative and intensive care medicine: a systematic review and meta-analysis.

BACKGROUND: Finger cuff technologies allow continuous noninvasive arterial blood pressure (AP) and cardiac output/index (CO/CI) monitoring. METHODS: We performed a meta-analysis of studies comparing finger cuff-derived AP and CO/CI measurements with invasive measurements in surgical or critically ill patients. We calculated overall random effects model-derived pooled estimates of the mean of the differences and of the percentage error (PE; CO/CI studies) with 95%-confidence intervals (95%-CI), pooled 95%-limits of agreement (95%-LOA), Cochran's Q and I2 (for heterogeneity). RESULTS: The pooled mean of the differences (95%-CI) was 4.2 (2.8 to 5.62) mm Hg with pooled 95%-LOA of -14.0 to 22.5 mm Hg for mean AP (Q=230.4 [P<0.001], I2=91%). For mean AP, the mean of the differences between finger cuff technologies and the reference method was ≤5±8 mm Hg in 9/27 data sets (33%). The pooled mean of the differences (95%-CI) was -0.13 (-0.43 to 0.18) L min-1 with pooled 95%-LOA of -2.56 to 2.23 L min-1 for CO (Q=66.7 [P<0.001], I2=90%) and 0.07 (0.01 to 0.13) L min-1 m-2 with pooled 95%-LOA of -1.20 to 1.15 L min-1 m-2 for CI (Q=5.8 [P=0.326], I2=0%). The overall random effects model-derived pooled estimate of the PE (95%-CI) was 43 (37 to 49)% (Q=48.6 [P<0.001], I2=63%). In 4/19 data sets (21%) the PE was ≤30%, and in 10/19 data sets (53%) it was ≤45%. CONCLUSIONS: Study heterogeneity was high. Several studies showed interchangeability between AP and CO/CI measurements using finger cuff technologies and reference methods. However, the pooled results of this meta-analysis indicate that AP and CO/CI measurements using finger cuff technologies and reference methods are not interchangeable in surgical or critically ill patients. CLINICAL TRIAL NUMBER: PROSPERO registration number: CRD42019119266.

Personalised haemodynamic management targeting baseline cardiac index in high-risk patients undergoing major abdominal surgery: a randomised single-centre clinical trial.

BACKGROUND: Despite several clinical trials on haemodynamic therapy, the optimal intraoperative haemodynamic management for high-risk patients undergoing major abdominal surgery remains unclear. We tested the hypothesis that personalised haemodynamic management targeting each individual's baseline cardiac index at rest reduces postoperative morbidity. METHODS: In this single-centre trial, 188 high-risk patients undergoing major abdominal surgery were randomised to either routine management or personalised haemodynamic management requiring clinicians to maintain personal baseline cardiac index (determined at rest preoperatively) using an algorithm that guided intraoperative i.v. fluid and/or dobutamine administration. The primary outcome was a composite of major complications (European Perioperative Clinical Outcome definitions) or death within 30 days of surgery. Secondary outcomes included postoperative morbidity (assessed by a postoperative morbidity survey), hospital length of stay, mortality within 90 days of surgery, and neurocognitive function assessed after postoperative Day 3. RESULTS: The primary outcome occurred in 29.8% (28/94) of patients in the personalised management group, compared with 55.3% (52/94) of patients in the routine management group (relative risk: 0.54, 95% confidence interval [CI]: 0.38 to 0.77; absolute risk reduction: -25.5%, 95% CI: -39.2% to -11.9%; P<0.001). One patient assigned to the personalised management group, compared with five assigned to the routine management group, died within 30 days after surgery (P=0.097). There were no clinically relevant differences between the two groups for secondary outcomes. CONCLUSIONS: In high-risk patients undergoing major abdominal surgery, personalised haemodynamic management reduces a composite outcome of major postoperative complications or death within 30 days after surgery compared with routine care. CLINICAL TRIAL REGISTRATION: NCT02834377.

Automated Ambulatory Blood Pressure Measurements and Intraoperative Hypotension in Patients Having Noncardiac Surgery with General Anesthesia: A Prospective Observational Study.

BACKGROUND: Normal blood pressure varies among individuals and over the circadian cycle. Preinduction blood pressure may not be representative of a patient's normal blood pressure profile and cannot give an indication of a patient's usual range of blood pressures. This study therefore aimed to determine the relationship between ambulatory mean arterial pressure and preinduction, postinduction, and intraoperative mean arterial pressures. METHODS: Ambulatory (automated oscillometric measurements at 30-min intervals) and preinduction, postinduction, and intraoperative mean arterial pressures (1-min intervals) were prospectively measured and compared in 370 American Society of Anesthesiology physical status classification I or II patients aged 40 to 65 yr having elective noncardiac surgery with general anesthesia. RESULTS: There was only a weak correlation between the first preinduction and mean daytime mean arterial pressure (r = 0.429, P < 0.001). The difference between the first preinduction and mean daytime mean arterial pressure varied considerably among individuals. In about two thirds of the patients, the lowest postinduction and intraoperative mean arterial pressures were lower than the lowest nighttime mean arterial pressure. The difference between the lowest nighttime mean arterial pressure and a mean arterial pressure of 65 mmHg varied considerably among individuals. The lowest nighttime mean arterial pressure was higher than 65 mmHg in 263 patients (71%). CONCLUSIONS: Preinduction mean arterial pressure cannot be used as a surrogate for the normal daytime mean arterial pressure. The lowest postinduction and intraoperative mean arterial pressures are lower than the lowest nighttime mean arterial pressure in most patients.

Continuous Noninvasive Arterial Pressure Monitoring in Obese Patients During Bariatric Surgery: An Evaluation of the Vascular Unloading Technique (Clearsight system).

BACKGROUND: Continuous monitoring of arterial pressure is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive arterial pressure monitoring are now available. In this study, we compared noninvasive arterial pressure measurements using the vascular unloading technique (Clearsight system; Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery. METHODS: In 35 severely obese patients (median body mass index, 47 kg/m2), we simultaneously recorded noninvasive and invasive arterial pressure measurements over a period of 45 minutes. We compared noninvasive (test method) and invasive (reference method) arterial pressure measurements (sampling rate 1 Hz = 1/s) using Bland-Altman analysis (accounting for multiple measurements per subject), 4-quadrant plot/concordance analysis (2-minute interval, 5 mm Hg exclusion zone), and error grid analysis (calculating the proportions of measurements in risk zones A-E with A indicating no risk, B low risk, C moderate risk, D significant risk, and E dangerous risk for the patient due to the risk of wrong clinical interventions because of measurement errors). RESULTS: We observed a mean of the differences (±SD, 95% limits of agreement) between the noninvasively and invasively assessed arterial pressure values of 1.1 mm Hg (±7.4 mm Hg, -13.5 to 15.6 mm Hg) for mean arterial pressure (MAP), 6.8 mm Hg (±10.3 mm Hg, -14.4 to 27.9 mm Hg) for systolic arterial pressure, and 0.8 mm Hg (±6.9 mm Hg, -12.9 to 14.4 mm Hg) for diastolic arterial pressure. The 4-quadrant plot concordance rate (ie, the proportion of arterial pressure measurement pairs showing concordant changes to all changes) was 93% (CI, 89%-96%) for MAP, 93% (CI, 89%-97%) for systolic arterial pressure, and 88% (CI, 84%-92%) for diastolic arterial pressure. Error grid analysis showed that the proportions of measurements in risk zones A-E were 89.5%, 10.0%, 0.5%, 0%, and 0% for MAP and 93.7%, 6.0%, 0.3%, 0%, and 0% for systolic arterial pressure, respectively. CONCLUSIONS: During laparoscopic bariatric surgery, the accuracy and precision of the vascular unloading technique (Clearsight system) was good for MAP and diastolic arterial pressure, but only moderate for systolic arterial pressure according to Bland-Altman analysis. The system showed good trending capabilities. In the error grid analysis, >99% of vascular unloading technique-derived arterial pressure measurements were categorized in no- or low-risk zones.

Continuous noninvasive arterial blood pressure monitoring using the vascular unloading technology during complex gastrointestinal endoscopy: a prospective observational study.

The innovative vascular unloading technology (VUT) allows continuous noninvasive arterial blood pressure (AP) monitoring. We aimed to investigate whether the VUT enables AP changes to be detected earlier compared with intermittent AP monitoring in patients undergoing gastrointestinal endoscopy. In this prospective observational study, we recorded continuous AP measurements with the VUT (CNAP system; CNSystems Medizintechnik AG, Graz, Austria) and intermittent AP measurements with upper arm cuff oscillometry in 90 patients undergoing complex gastrointestinal endoscopy (Department of Interventional Endoscopy at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany). A "hypotensive phase" was defined as a time period of at least 30 s during which ≥ 50% of the VUT-AP values were in a predefined range of hypotension, i.e., AP value a) ≥ 10% below the last oscillometric value and b) ≤ 65 mmHg for mean AP or ≤ 90 mmHg for systolic AP. In the 5-min-interval between two oscillometric measurements, one or more hypotensive phases were detected in 26 patients (29%) for mean AP and in 27 patients (30%) for systolic AP. Hypotensive phases had a mean duration of 195 ± 99 s for mean AP and 197 ± 97 s for systolic AP with a mean procedure duration of 36 (± 21) min. Continuous noninvasive AP monitoring using the VUT enables hypotensive phases to be detected earlier compared with intermittent AP monitoring during complex gastrointestinal endoscopy. These hypotensive phases may be missed or only belatedly recognized with intermittent AP monitoring. Continuous noninvasive AP measurement facilitates detecting hemodynamic instability more rapidly and therefore may improve patient safety.

Error Grid Analysis for Arterial Pressure Method Comparison Studies.

The measurement of arterial pressure (AP) is a key component of hemodynamic monitoring. A variety of different innovative AP monitoring technologies became recently available. The decision to use these technologies must be based on their measurement performance in validation studies. These studies are AP method comparison studies comparing a new method ("test method") with a reference method. In these studies, different comparative statistical tests are used including correlation analysis, Bland-Altman analysis, and trending analysis. These tests provide information about the statistical agreement without adequately providing information about the clinical relevance of differences between the measurement methods. To overcome this problem, we, in this study, propose an "error grid analysis" for AP method comparison studies that allows illustrating the clinical relevance of measurement differences. We constructed smoothed consensus error grids with calibrated risk zones derived from a survey among 25 specialists in anesthesiology and intensive care medicine. Differences between measurements of the test and the reference method are classified into 5 risk levels ranging from "no risk" to "dangerous risk"; the classification depends on both the differences between the measurements and on the measurements themselves. Based on worked examples and data from the Multiparameter Intelligent Monitoring in Intensive Care II database, we show that the proposed error grids give information about the clinical relevance of AP measurement differences that cannot be obtained from Bland-Altman analysis. Our approach also offers a framework on how to adapt the error grid analysis for different clinical settings and patient populations.

Continuous Noninvasive Arterial Pressure Monitoring Using the Vascular Unloading Technique (CNAP System) in Obese Patients During Laparoscopic Bariatric Operations.

BACKGROUND: Increasing rates of obesity create new challenges for hemodynamic monitoring in the perioperative phase. Continuous monitoring of arterial pressure (AP) is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive AP monitoring are now available. In this study, we aimed to compare continuous noninvasive AP measurements using the vascular unloading technique (CNAP system; CNSystems, Graz, Austria) compared with invasive AP measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery. METHODS: In 29 severely obese patients (mean body mass index 48.1 kg/m), we simultaneously recorded noninvasive and invasive AP measurements over a period of 45 minutes and averaged the measurements using 10-second episodes. We compared noninvasive (test method) and invasive (reference method) AP measurements using Bland-Altman analysis and 4-quadrant plot/concordance analysis (2-minute interval). RESULTS: We observed a mean of the differences (±SD, 95% limits of agreement) between the AP values obtained by the CNAP system and the invasively assessed AP values of 7.9 mm Hg (±9.6 mm Hg, -11.2 to 27.0 mm Hg) for mean AP, 4.8 mm Hg (±15.8 mm Hg, -26.5 to 36.0 mm Hg) for systolic AP, and 9.5 mm Hg (±10.3 mm Hg, -10.9 to 29.9 mm Hg) for diastolic AP, respectively. The concordance rate was 97.5% for mean AP, 95.0% for systolic AP, and 96.7% for diastolic AP, respectively. CONCLUSIONS: In the setting of laparoscopic bariatric surgery, continuous noninvasive AP monitoring with the CNAP system showed good trending capabilities compared with continuous invasive AP measurements obtained with a radial arterial catheter. However, absolute CNAP- and arterial catheter-derived AP values were not interchangeable.