Changes in the corrected carotid flow time can predict spinal anesthesia-induced hypotension in patients undergoing cesarean delivery: an observational study.

PURPOSE: Spinal anesthesia is a standard technique for cesarean delivery; however, it possesses a risk of hypotension. We hypothesised that the changes in the corrected flow time induced by the Trendelenburg position could predict the incidence of hypotension after spinal anesthesia for cesarean delivery. METHODS: Patients undergoing elective cesarean delivery under spinal anesthesia were enrolled. Before anesthesia induction, corrected flow time was measured in the supine and Trendelenburg positions (FTc-1 and FTc-2, respectively). Additionally, a percent change in corrected flow time induced by the Trendelenburg position was defined as ΔFTc. The primary endpoint was to investigate the ability of ΔFTc to predict the incidence of spinal anesthesia-induced hypotension until delivery. The receiver operating characteristics curves to assess the ability of FTc-1, FTc-2, and ΔFTc to predict the incidence of hypotension were generated. RESULTS: Finally, 40 patients were included, and of those, 26 (65%) developed spinal anesthesia-induced hypotension. The areas under the curve for FTc-1, FTc-2, and ΔFTc were 0.591 (95% CI: 0.424 to 0.743) (P = 0.380), 0.742 (95% CI: 0.579 to 0.867) (P = 0.004), and 0.882 (95% CI: 0.740 to 0.962) (P < 0.001) respectively, indicating ΔFTc as the best predictor among these three parameters. The best threshold for ΔFTc was 6.4% (sensitivity: 80.8% (95% CI: 53.8 to 96.2), specificity: 85.7% (95% CI: 42.9 to 100.0)). CONCLUSIONS: This study demonstrated that changes in the corrected carotid flow time induced by the Trendelenburg position could serve as a good predictor of spinal anesthesia-induced hypotension for cesarean delivery.

Fixing the anesthesia research crisis in Japan.

To explore the current status of anesthesia research activity in Japan, we analyzed the number of abstracts presented at the Japanese Society of Anesthesiologists (JSA) annual meetings by several factors including gender, society branches, and subspecialty categories. The number of abstracts at JSA annual meetings has declined sharply since 2016 with no gender gap. A decrease in the neurological field predated the overall decline, but other subspecialty categories showed a similar decline. Although the Tokyo, Tokai-Hokuriku, and Kyushu branches were responsible for more than half of the reduction, the trend was similar among all branches. In a survey regarding academic activities of university hospital residents and faculty, Ph.D. aspirants' rate was only 20-30%. Residents had never presented an abstract at scientific conferences and never published any papers at nearly 40% and 30% of the university hospitals, respectively. Our survey suggests that junior anesthetists are losing interest in research. Senior faculty and mentors must redouble efforts to embed and encourage research in departments and by anesthetists in training. If a revival of anesthesia research in Japan does not occur then a service only specialty awaits.

Validation of Continuous Noninvasive Blood Pressure Monitoring Using Error Grid Analysis.

BACKGROUND: Error grid analysis was recently proposed to compare blood pressure obtained by 2 measurement methods. This study aimed to compare continuous noninvasive blood pressure (CNBP) with invasive blood pressure (IBP) using the error grid analysis and investigate the confounding risk factors attributable to the differences between CNBP and IBP. METHODS: Sixty adult patients undergoing general anesthesia were prospectively enrolled. Simultaneous comparative data regarding CNBP and IBP were collected. The Bland-Altman analysis was conducted to compare CNBP and IBP for systolic blood pressure (SBP) and mean blood pressure (MBP; acceptable accuracy: mean bias <5 mm Hg; standard deviation <8 mm Hg). The clinical relevance of the discrepancies between CNBP and IBP was evaluated by the error grid analysis, which classifies the differences into 5 zones from "no risk" (A) to "dangerous risk" (E). Additionally, an ordinal logistic regression analysis was performed to evaluate the relationship between the risk zones for MBP, classified by the error grid analysis and covariates of interest. RESULTS: A total of 10,663 pairs of CNBP/IBP were finally analyzed. The Bland-Altman analysis showed an acceptable accuracy with a bias of -3.3 ± 5.6 mm Hg for MBP but a poor accuracy with a bias of 5.4 ± 10.5 mm Hg for SBP. The error grid analysis showed the proportions of zones A to E as 96.7%, 3.2%, 0.1%, 0%, and 0% for SBP, respectively, and 72.0%, 27.9%, 0.1%, 0%, and 0% for MBP, respectively. The finger cuff missed 23.9% of epochs when SBP <90 mm Hg and 55.3% of epochs when MBP <65 mm Hg. The ordinal logistic regression analysis revealed that older age (adjusted odds ratio for decade: 1.54, 95% confidence interval [CI], 1.15-2.08; P = .004) and length of time from the initiation of finger cuff inflation (adjusted odds ratio for 60 minutes: 1.40, 95% CI, 1.13-1.73; P = .002) were significant factors of being in a more dangerous zone of the error grid. CONCLUSIONS: The error grid analysis revealed the larger clinical discrepancy between CNBP and IBP in MBP compared with that in SBP. Old age and longer finger cuff inflation time were significant factors of being in a more dangerous zone of the error grid, which could affect the hemodynamic management during surgery.

Postoperative Pulmonary Complications After Cardiac Surgery: The VENICE International Cohort Study.

OBJECTIVE: Postoperative pulmonary complications (PPC) remain a main issue after cardiac surgery. The objective was to report the incidence and identify risk factors of PPC after cardiac surgery. DESIGN: An international multicenter prospective study (42 international centers in 9 countries). PARTICIPANTS: A total of 707 adult patients who underwent cardiac surgery under cardiopulmonary bypass. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: During a study period of 2 weeks, the investigators included all patients in their respective centers and screened for PPCs. PPC was defined as the occurrence of at least 1 pulmonary complication among the following: atelectasis, pleural effusion, respiratory failure, respiratory infection, pneumothorax, bronchospasm, or aspiration pneumonitis. Among 676 analyzed patients, 373 patients presented with a PPC (55%). The presence of PPC was significantly associated with a longer intensive care length of stay and hospital length of stay. One hundred ninety (64%) patients were not intraoperatively ventilated during cardiopulmonary bypass. Ventilation settings were similar regarding tidal volume, respiratory rate, inspired oxygen. In the regression model, age, the Euroscore II, chronic obstructive pulmonary disease, preoxygenation modality, intraoperative positive end-expiratory pressure, the absence of pre- cardiopulmonary bypass ventilation, the absence of lung recruitment, and the neuromuscular blockade were associated with PPC occurrence. CONCLUSION: Both individual risk factors and ventilatory settings were shown to explain the high level of PPCs. These findings require further investigations to assess a bundle strategy for optimal ventilation strategy to decrease PPC incidence.

Changes in corrected carotid flow time induced by recruitment maneuver predict fluid responsiveness in patients undergoing general anesthesia.

Non-invasive methods to assess patients' fluid responsiveness during lung-protective ventilation are needed. We hypothesized changes in the corrected carotid flow time induced by the recruitment maneuver predict fluid responsiveness under general anesthesia. Thirty patients undergoing general anesthesia in the supine position were prospectively enrolled. The study protocol was conducted when the patient was hemodynamically stable during surgery. Flow time was measured on Doppler images of the common carotid artery. Carotid flow time, heart rate, stroke volume, stroke volume variation, and pulse pressure variation were recorded before and after a recruitment maneuver at a continuous airway pressure of 30 cmH2O for 30 s, and before and after volume expansion with 250 mL for 10 min. Patients were defined as fluid responders if the increase in stroke volume was > 10% after volume expansion. Twenty patients (67%) were fluid responders. All Doppler images for carotid flow time were obtained within 30 s. Changes in the corrected flow time accurately predicted fluid responsiveness (area under the curve: 0.82, 95% confidence interval [CI] 0.64-0.94, p = 0.002). The optimal threshold for changes in the corrected flow time was - 11.7% with a sensitivity of 95.0% (95% CI 75.1-99.9%) and a specificity of 80.0% (95% CI 44.4-97.5%). The gray-zone of changes in the corrected flow time was from - 25.1 to - 12.2% and included 12 patients (40%). Changes in the corrected carotid flow time were a useful, technically easy-to-perform, and non-invasive method to predict fluid responsiveness without a need for hemodynamic monitoring or arterial cannulation.

Hemodynamic Changes via the Lung Recruitment Maneuver Can Predict Fluid Responsiveness in Stroke Volume and Arterial Pressure During One-Lung Ventilation.

BACKGROUND: We aimed to evaluate the ability of lung recruitment maneuver-induced hemodynamic changes to predict fluid responsiveness in patients undergoing lung-protective ventilation during one-lung ventilation (OLV). METHODS: Thirty patients undergoing thoracic surgery with OLV (tidal volume: 6 mL/kg of ideal body weight and positive end-expiratory pressure: 5 cm H2O) were enrolled. The study protocol began 30 minutes after starting OLV. Simultaneous recordings were performed for hemodynamic variables of heart rate, mean arterial pressure (MAP), stroke volume (SV), pulse pressure variation (PPV), and stroke volume variation (SVV) were recorded at 4 time points: before recruitment maneuver (continuous airway pressure: 30 cm H2O for 30 seconds), at the end of recruitment maneuver, and before and after volume loading (250 mL over 10 minutes). Patients were recognized as fluid responders if the increase in SV or MAP was >10%. Receiver operating characteristic curves for percent decrease in SV and MAP by recruitment maneuver (ΔSVRM and ΔMAPRM, respectively) were generated to evaluate the ability to discriminate fluid responders from nonresponders. The gray-zone approach was applied for ΔSVRM and ΔMAPRM. RESULTS: Of 30 patients, there were 17 SV-responders (57%) and 12 blood pressure (BP)-responders (40%). Area under the curve (AUC) for ΔSVRM to discriminate SV-responders from nonresponders was 0.84 (95% confidence interval [CI], 0.67-0.95; P < .001). The best threshold for ΔSVRM to discriminate the SV-responders was -23.7% (95% CI, -41.2 to -17.8; sensitivity, 76.5% [95% CI, 50.1-93.2]; specificity, 84.6% [95% CI, 54.6-98.1]). For BP-responders, AUC for ΔMAPRM was 0.80 (95% CI, 0.61-0.92, P < .001). The best threshold for ΔMAPRM was -17.3% (95% CI, -23.9 to -5.1; sensitivity, 75.0% [95% CI, 42.8-94.5]; specificity, 77.8% [95% CI, 52.4-93.6]). With the gray-zone approach, the inconclusive range of ΔSVRM for SV-responders was -40.1% to -13.8% including 13 (43%) patients, and that of ΔMAPRM was -23.9% to -5.1%, which included 16 (53%) patients. CONCLUSIONS: ΔSVRM and ΔMAPRM could predict hemodynamic responses after volume expansion during OLV.

Changes in stroke volume induced by lung recruitment maneuver can predict fluid responsiveness during intraoperative lung-protective ventilation in prone position.

BACKGROUND: The present study aimed to evaluate the reliability of hemodynamic changes induced by lung recruitment maneuver (LRM) in predicting stroke volume (SV) increase after fluid loading (FL) in prone position. METHODS: Thirty patients undergoing spine surgery in prone position were enrolled. Lung-protective ventilation (tidal volume, 6-7 mL/kg; positive end-expiratory pressure, 5 cmH2O) was provided to all patients. LRM (30 cmH2O for 30 s) was performed. Hemodynamic variables including mean arterial pressure (MAP), heart rate, SV, SV variation (SVV), and pulse pressure variation (PPV) were simultaneously recorded before, during, and at 5 min after LRM and after FL (250 mL in 10 min). Receiver operating characteristic curves were generated to evaluate the predictability of SVV, PPV, and SV decrease by LRM (ΔSVLRM) for SV responders (SV increase after FL > 10%). The gray zone approach was applied for ΔSVLRM. RESULTS: Areas under the curve (AUCs) for ΔSVLRM, SVV, and PPV to predict SV responders were 0.778 (95% confidence interval: 0.590-0.909), 0.563 (0.371-0.743), and 0.502 (0.315-0.689), respectively. The optimal threshold for ΔSVLRM was 30% (sensitivity, 92.3%; specificity, 70.6%). With the gray zone approach, the inconclusive values ranged 25 to 75% for ΔSVLRM (including 50% of enrolled patients). CONCLUSION: In prone position, LRM-induced SV decrease predicted SV increase after FL with higher reliability than traditional dynamic indices. On the other hand, considering the relatively large gray zone in this study, future research is needed to further improve the clinical significance. TRIAL REGISTRATION: UMIN Clinical Trial Registry UMIN000027966 . Registered 28th June 2017.

Effect of Systemic Vascular Resistance on the Reliability of Noninvasive Hemodynamic Monitoring in Cardiac Surgery.

OBJECTIVE: To assess the effect of systemic vascular resistance (SVR) on the reliability of the ClearSight system (Edwards Lifesciences, Irvine, CA) for measuring blood pressure (BP) and cardiac output (CO). DESIGN: Observational study. SETTING: University hospital. PARTICIPANTS: Twenty-five patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BP, measured using ClearSight and an arterial line, and CO, measured using ClearSight and a pulmonary artery catheter, were recorded before (T1) and two minutes after phenylephrine or ephedrine administration. Bland-Altman analysis was used to compare BP and CO measurements at T1. A polar plot was used to assess trending abilities. Patients were divided into the following three groups according to the SVR index (SVRI) at T1: low (<1,200 dyne s/cm5/m2), normal (1,200-25,00 dyne s/cm5/m2), and high (>2,500 dyne s/cm5/m2). The bias in BP and CO was -4.8 ± 8.9 mmHg and 0.10 ± 0.81 L/min, respectively, which was correlated significantly with SVRI (p < 0.05). The percentage error in CO was 40.6%, which was lower in the normal SVRI group (33.3%) than the low and high groups (46.3% and 47.7%, respectively). The angular concordance rate was 96.3% and 95.4% for BP and 87.0% and 92.5% for CO after phenylephrine and ephedrine administration, respectively. There was a low tracking ability for CO changes after phenylephrine administration in the low-SVRI group (angular concordance rate 33.3%). CONCLUSION: The ClearSight system showed an acceptable accuracy in measuring BP and tracking BP changes in various SVR states; however, the accuracy of CO measurement and its trending ability in various SVR states was poor.

Preoperative assessment for scheduling surgery during the coronavirus disease pandemic.

On Mar 11, 2020, the World Health Organization declared coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a pandemic. Because COVID-19 has a pre-symptomatic period of up to 2 weeks, SARS-CoV-2 infection has continued to spread. Some individuals with SARS-CoV-2 infection have a severe clinical course, while most individuals have mild or moderate symptoms. Because SARS-CoV-2 is transmitted via droplets and secretions, anesthesiologists have higher risks of infection, especially during airway management. Therefore, general anesthesia requiring airway management can be a challenging procedure for anesthesiologists. During the pandemic, many elective surgeries have been postponed or cancelled in most affected countries. Recently, the number of elective surgeries is gradually recovering from the effect of the COVID-19 pandemic, and hence, safe clinical practice and protocols to prevent SARS-CoV-2 transmission to medical staff should be established. This mini-review focuses on the preoperative assessment and decision with regard to scheduling surgery in elective and emergency cases during the COVID-19 pandemic. A standardized questionnaire and algorithm regarding COVID-19 should be used to assess surgical patients preoperatively as it increases the reproducibility and accuracy of the decision whether to proceed with surgery.

Error grid analysis for risk management in the difference between invasive and noninvasive blood pressure measurements.

PURPOSE: Invasive arterial blood pressure (IAP) and noninvasive blood pressure (NIBP) measurements are both common methods. Recently, a new method of error grid analysis was proposed to compare blood pressure obtained using two measurement methods. This study aimed to compare IAP and NIBP measurements using the error grid analysis and investigate potential confounding factors affecting the discrepancies between IAP and NIBP. METHODS: Adult patients who underwent general anesthesia in the supine position with both IAP and NIBP measurements were retrospectively investigated. The error grid analyses were performed to compare IAP and NIBP. In the error grid analysis, the clinical relevance of the discrepancies between IAP and NIBP was evaluated and classified into five zones from no risk (A) to dangerous risk (E). RESULTS: Overall, data of 1934 IAP/NIBP measurement pairs from 100 patients were collected. The error grid analysis revealed that the proportions of zones A-E for systolic blood pressure were 96.4%, 3.5%, 0.05%, 0%, and 0%, respectively. In contrast, the proportions for mean blood pressure were 82.5%, 16.7%, 0.8%, 0%, and 0%, respectively. The multiple regression analysis revealed that continuous phenylephrine administration (p = 0.016) and age (p = 0.044) were the significant factors of an increased clinical risk of the differences in mean blood pressure. CONCLUSIONS: The error grid analysis indicated that the differences between IAP and NIBP for mean blood pressure were not clinically acceptable and had the risk of leading to unnecessary treatments. Continuous phenylephrine administration and age were the significant factors of an increased clinical risk of the discrepancies between IAP and NIBP.

Impact of intraoperative goal-directed fluid therapy on major morbidity and mortality after transthoracic oesophagectomy: a multicentre, randomised controlled trial.

BACKGROUND: Transthoracic oesophagectomy is associated with major morbidity and mortality, which may be reduced by goal-directed therapy (GDT). The aim of this multicentre, RCT was to evaluate the impact of intraoperative GDT on major morbidity and mortality in patients undergoing transthoracic oesophagectomy. METHODS: Adult patients undergoing transthoracic oesophagectomy were randomised to receive either minimally invasive intraoperative GDT (stroke volume variation <8%, plus systolic BP maintained >90 mm Hg by pressors as necessary) or haemodynamic management left to the discretion of attending senior anaesthetists (control group; systolic BP >90 mm Hg alone). The primary outcome was the incidence of death or major complications (reoperation for bleeding, anastomotic leakage, pneumonia, reintubation, >48 h ventilation). A Cox proportional hazard model was used to examine whether the effects of GDT on morbidity and mortality were independent of other potential confounders. RESULTS: A total of 232 patients (80.6% male; age range: 36-83 yr) were randomised to either GDT (n=115) or to the control group (n=117). After surgery, major morbidity and mortality were less frequent in 22/115 (19.1%) subjects randomised to GDT, compared with 41/117 (35.0%) subjects assigned to the control group {absolute risk reduction: 15.9% (95% confidence interval [CI]: 4.7-27.2%); P=0.006}. GDT was also associated with fewer episodes of atrial fibrillation (odds ratio [OR]: 0.18 [95% CI: 0.05-0.65]), respiratory failure (OR: 0.27 [95% CI: 0.09-0.83]), use of mini-tracheotomy (OR: 0.29 [95% CI: 0.10-0.81]), and readmission to ICU (OR: 0.09 [95% CI: 0.01-0.67]). GDT was independently associated with morbidity and mortality (hazard ratio: 0.51 [95% CI: 0.30-0.87]; P=0.013). CONCLUSIONS: Intraoperative GDT may reduce major morbidity and mortality, and shorten hospital stay, after transthoracic oesophagectomy. CLINICAL TRIAL REGISTRATION: UMIN000018705.

Impact of deep breathing on predictability of stroke volume variation in spontaneous breathing patients.

BACKGROUND: This study investigated the ability of stroke volume variation (SVV) during deep breathing to discriminate fluid responders among spontaneously breathing patients. METHODS: Thirty patients undergoing general anaesthesia were enrolled and assessed before anaesthetic induction. Haemodynamic variables, including stroke volume (SV) and SVV, were measured using the ClearSight system during normal breathing. After these measurements, each patient was required to maintain deep breathing (6 breaths min-1 ) and haemodynamic variables were recorded. Then, the table was adjusted to the Trendelenburg position (15°) for 2 minutes, and haemodynamic variables were measured. Receiver operating characteristic curves were created for SVV during normal and deep breathing, and the difference in SVV between normal and deep breathing (ΔSVV) to discriminate fluid responders (SV increase >10% after changing position). The correlation between SV increase and ΔSVV was examined using Pearson's correlation coefficient. The grey zone approach was used to assess the inconclusive range of the haemodynamic variables. RESULTS: Receiver operating characteristic curve analysis indicated that ΔSVV showed good reliability in predicting fluid responsiveness (AUC: 0.850; 95% CI: 0.672-0.953; threshold: 4%, sensitivity: 75.0%, specificity: 88.9%], while SVV during normal breathing did not (AUC: 0.579; 95% CI: 0.386-0.756)]. Although SVV during deep breathing exhibited acceptable predictability (AUC: 0.778; 95% CI: 0.589-0.908), the sensitivity was not good (58.3%). With the grey zone approach, the inconclusive range of ΔSVV was small with the range of 1.4%-4.2% (23% of patients). CONCLUSION: Deep breathing could improve the reliability of dynamic indices in spontaneously breathing patients. TRIAL REGISTRATION: UMIN-CTR, identifer: UMIN000027970. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000032040.

Comparison of the venous-arterial CO2 to arterial-venous O2 content difference ratio with the venous-arterial CO2 gradient for the predictability of adverse outcomes after cardiac surgery.

This study aimed to compare the prognostic performance of the ratio of mixed and central venous-arterial CO2 tension difference to arterial-venous O2 content difference (Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2, respectively) with that of the mixed and central venous-to-arterial carbon dioxide gradient (Pv-aCO2 and Pcv-aCO2, respectively) for adverse events after cardiac surgery. One hundred and ten patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled. After catheter insertion, three blood samples were withdrawn simultaneously through arterial pressure, central venous, and pulmonary artery catheters, before and at the end of the operation, and preoperative and postoperative values were determined. The primary end-point was set as the incidence of postoperative major organ morbidity and mortality (MOMM). Receiver operating characteristic (ROC) curve and multivariate logistic regression analyses were performed to evaluate the prognostic reliability of Pv-aCO2, Pcv-aCO2, Pv-aCO2/Ca-vO2, and Pcv-aCO2/Ca-cvO2 for MOMM. MOMM events occurred in 25 patients (22.7%). ROC curve analysis revealed that both postoperative Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2 were significant predictors of MOMM. However, postoperative Pv-aCO2 was the best predictor of MOMM (area under the curve [AUC]: 0.804; 95% confidence interval [CI] 0.688-0.921), at a 5.1-mmHg cut-off, sensitivity was 76.0%, and specificity was 74.1%. Multivariate analysis revealed that postoperative Pv-aCO2 was an independent predictor of MOMM (odds ratio [OR]: 1.42, 95% CI 1.01-2.00, p = 0.046) and prolonged ICU stay (OR: 1.45, 95% CI 1.05-2.01, p = 0.024). Pv-aCO2 at the end of cardiac surgery was a better predictor of postoperative complications than Pv-aCO2/Ca-vO2 and Pcv-aCO2/Ca-cvO2.

The Sum of Early Diastolic Annulus Velocities in the Mitral and Tricuspid Valve Can Predict Adverse Events After Cardiac Surgery.

OBJECTIVES: To assess whether a tissue Doppler imaging (TDI)-based parameter consisting of the sum of early diastolic velocities of the mitral annulus (Me') and tricuspid annulus (Te') can serve as a predictor of adverse outcomes after cardiac surgery. DESIGN: Prospective, observational study. SETTING: University hospital. PARTICIPANTS: The study comprised 100 patients undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After anesthetic induction, transesophageal echocardiography was performed to obtain the values of the early transmitral flow velocity (E), Me', and Te'. The primary endpoint was the incidence of postoperative major organ morbidity and mortality (MOMM) events, including death, redo surgery, prolonged ventilation, stroke, sternal infection, and dialysis. Receiver operating characteristic and multivariate logistic analyses were used to examine the prognostic performance of TDI-based parameters for predicting MOMM incidence. The secondary endpoint was the incidence of death or rehospitalization for cardiovascular disease within 1 year post-discharge. TDI-based parameters were measured in 87 of the 100 patients enrolled. Me' plus Te' had better prognostic ability (area under the curve 0.771; threshold 13 cm/s; sensitivity 86.7%; specificity 64.9%) than that of Me' or E to Me' (E/Me')% and was an independent predictor of MOMM (odds ratio 0.45; 95% confidence interval 0.28-0.74, p = 0.001), whereas Me' was not. Lower Me' plus Te' (≤13 cm/s) was associated with a significantly higher incidence and earlier onset of cardiovascular events within 1 year post-discharge (p = 0.012). CONCLUSIONS: Compared with Me' and E/Me', which traditionally are used for assessing diastolic function, Me' plus Te' showed better prognostic ability for both short- and long-term outcomes of cardiac surgery.

Pre-anesthetic stroke volume variation can predict cardiac output decrease and hypotension during induction of general anesthesia.

This study aimed to assess the reliability of stroke volume variation (SVV) in predicting cardiac output (CO) decrease and hypotension during induction of general anesthesia. Forty-five patients undergoing abdominal surgery under general anesthesia were enrolled. Before induction of anesthesia, patients were required to maintain deep breathing (6-8 times/min), and pre-anesthetic SVV was measured for 1 min by electrical cardiometry. General anesthesia was induced with propofol, remifentanil, rocuronium, and sevoflurane. Study duration was defined from the start of fluid administration till 5 min after tracheal intubation. Blood pressure (BP) was measured every minute. Cardiac output was measured continuously by electrical cardiometry. Receiver operating characteristics (ROC) curves were made regarding the incidence of decreased CO (less than 70% of the baseline) and hypotension (mean BP <65 mmHg). The risk of developing decreased CO and hypotension was evaluated by multivariate logistic regression analysis. The time from the start of the procedure to onset of decreased CO was analyzed by the Kaplan-Meier method. The area under the ROC curve and optimal threshold value of pre-anesthetic SVV for predicting decreased CO and hypotension were 0.857 and 0.693. Patients with lower SVV exhibited a significantly slower onset and lower incidence of decreased CO than those with higher SVV (p = 0.003). Multivariate logistic regression analysis indicated high pre-anesthetic SVV as being an independent risk factor for decreased CO and hypotension (odds ratio, 1.43 and 1.16, respectively). In conclusions, pre-anesthetic SVV can predict incidence of decreased CO and hypotension during induction of general anesthesia.

Impact of continuous non-invasive blood pressure monitoring on hemodynamic fluctuation during general anesthesia: a randomized controlled study.

This study assessed the ability of a continuous non-invasive blood pressure (BP) monitoring system to reduce intra-anesthetic hemodynamic fluctuation compared with intermittent BP cuff measurement. Forty patients undergoing total knee arthroplasty under general anesthesia were enrolled and randomly divided into two groups (Control and CS group). BP management was performed using the same protocol with BP measured by intermittent BP cuff in the Control and that by continuous non-invasive BP monitoring in the CS group. We assessed the accuracy and precision of the continuous non-invasive BP monitoring compared with BP cuff measurement using Bland-Altman, four-quadrant plot, and polar-plot analyses. Additionally, the occurrence of hypotension and hypertention during general anesthesia was compared between the two groups. The continuous non-invasive BP monitoring showed excellent accuracy of - 1.1 ± 8.1 mmHg during surgery and an acceptable trending ability with a concordance rate of 95.1% according to the four-quadrant plot analysis and an angular concordance rate of 86.7% by polar-plot analysis. Hypotension was less common in the CS group during induction of anesthesia (p = 0.002) and surgery (p = 0.008). Hypertension occurred more frequently in the Control group during emergence from anesthesia (p = 0.037). The duration of hemodynamic stability (systolic BP 80-110% of baseline) intraoperatively was longer in the CS group than in the Control group (87.7 vs. 61.9%; p < 0.001). Accuracy and trending ability of the continuous non-invasive BP monitoring was clinically acceptable, and lead to hemodynamic stability and reduction of intra-anesthetic hypotension and hypertension intraoperatively.

Impact of non-invasive continuous blood pressure monitoring on maternal hypotension during cesarean delivery: a randomized-controlled study.

PURPOSE: This study aimed to investigate the efficacy of the ClearSight™ system (Edwards Lifesciences, Irvine, CA) for reducing the incidence of hypotension compared with the traditional oscillometric blood pressure monitoring in cesarean delivery under spinal anesthesia. METHODS: Forty patients undergoing cesarean delivery under spinal anesthesia were enrolled. The patients were randomly divided into two groups (Control and ClearSight groups). All patients received spinal anesthesia using 0.5% hyperbaric bupivacaine (11.5 mg) and fentanyl (10 µg). Blood pressure was managed with the same protocol using the ClearSight™ system (ClearSight group) and oscillometric blood pressure monitoring (Control group). Furthermore, we compared the accuracy of the ClearSight™ system with the traditional oscillometric monitoring for blood pressure measurement using Bland-Altman, four-quadrant plot, and polar plot analyses. RESULTS: The incidence of hypotension was significantly lower in the ClearSight group from induction to delivery (45% vs. 0%, p < 0.001) and to the end of surgery (50% vs. 20%, p = 0.049). Intraoperative nausea occurred more frequently in the Control group (45% vs. 10%, p = 0.012). The ClearSight™ system demonstrated acceptable accuracy with a bias of - 4.3 ± 11.7 mmHg throughout the procedure. Four-quadrant analysis revealed an excellent trending ability of the ClearSight™ system with a concordance rate of approximately 95%. In the polar plot analysis, the angular bias and concordance rate were - 13.5° ± 19.0° and 76.9%, respectively. CONCLUSIONS: The accuracy and trending ability of the ClearSight™ system for blood pressure measurement was clinically acceptable in cesarean delivery under spinal anesthesia, leading to reductions in maternal hypotension and nausea.

Transcutaneous near-infrared spectroscopy for monitoring spinal cord ischemia: an experimental study in swine.

We aimed to assess the ability of near-infrared spectroscopy (NIRS) to detect spinal cord ischemia, and to evaluate changes in regional oxygen saturation (rSO2) following recovery of spinal cord circulation and cerebrospinal fluid drainage. Four 12-month-old female swine weighing 28.7-29.5 kg were acquired for this study. NIRS probes were placed along the midline of the upper (T6/7) and lower (T9/T10) thoracic vertebrae. The thoracic aorta was clamped distal of the left subclavian artery to induce spinal ischemia. Aortic cross-clamping was maintained for 30 min. Fifteen minutes after aortic de-clamping, the cerebrospinal fluid drainage catheter was opened to air, and cerebrospinal fluid drainage was initiated. Following aortic clamping, rSO2 in both upper and lower regions of the spinal cord decreased by 15 % within 5 min and by 20 % within 10 min (relative change). After aortic de-clamping, rSO2 values in both regions returned to baseline within 5 min. No changes in rSO2 in either the upper or lower vertebrae were observed following initiation of cerebrospinal fluid drainage. Histological analysis revealed that ischemic changes had occurred in all spinal levels. NIRS may be used to detect decreases in and recovery of spinal cord circulation following aortic clamping and de-clamping, whereas it may not reflect minor changes in spinal cord circulation due to cerebrospinal fluid drainage. Further clinical studies are required to investigate the potential for NIRS as an index of spinal cord circulation.