Phase Angle as a Reliable Biomarker of Frailty to Predict Postoperative Outcomes in Patients Undergoing Off-Pump Coronary Artery Grafting: A Prospective Observational Study.

OBJECTIVE: To elucidate the association between phase angle (PA) and a composite adverse outcome in patients requiring off-pump coronary artery bypass grafting (OPCAB). DESIGN: A prospective observational study. SETTING: High-volume single center. PARTICIPANTS: A total of 229 adult patients who underwent OPCAB from May 2019 to October 2020. INTERVENTIONS: Each patient underwent bioelectrical impedance analysis, including PA assessment before surgery (PApre), immediately postoperatively (PApost), and 1 day postoperatively (PAPOD1), using an Inbody S10. Frailty index and nutritional assessments also were obtained before surgery. MEASUREMENTS AND MAIN RESULTS: Patient outcomes were assessed using a composite adverse outcome comprising death, myocardial infarction, revascularization, new-onset atrial fibrillation, acute kidney injury, stroke, postoperative pulmonary complications, wound complications, sepsis, reoperation, and/or delirium occurring during hospitalization and over the following year. Patients for whom composite adverse outcomes were reported had lower PApre than those without complications (5.4 ± 0.9 v 6.0 ± 0.9, p < 0.001). The PA was significantly associated with in-hospital and 1-year composite postoperative outcomes. The odds ratios (OR, [95% confidence interval]) for PApre by time were in-hospital complications (0.435 [0.314, 0.604], p < 0.001; 1-year complications: 0.459 [0.330, 0.638], p < 0.001) and PAPOD1 (OR, in-hospital complications: 0.400 [0.277, 0.576], 1-year complications: 0.429 [0.298, 0.619], p < 0.001). The PApre was significantly associated with days alive and out of hospital until 1 year. The cut-off value of PApre for optimal prediction of in-hospital complications was 6.0 (area under the curve: 0.691 [0.623-0.758], p < 0.001). CONCLUSION: Low PA as an indicator of frailty is associated with adverse postoperative outcomes after OPCAB. Low PA may be employed as a noninvasive and practical tool for the prediction of prognosis in patients with coronary artery disease.

Effects of infusion tubing line lengths and syringe sizes on infusion system compliance: an experimental study using a syringe-type infusion pump at low flow rate.

Ideally, the flow delivery of an infusion system is proportional only to the rate of mechanical actuation of the syringe pump plunger. However, in the real world, overall infusion system compliance may be affected by components such as an extension of tubing lines, or different sizes of syringes. With higher compliance, there may be greater chances of flow irregularity. In this experimental study, we investigated the effects of lengths of infusion lines and syringe sizes on the compliance of syringe pumps with low flow rate (2 ml h-1). In the first experiment, infusion system compliance was measured in various settings by occlusion release. As the infusion tubing length and size of the syringe increased, the time to reach each pressure was delayed and the infusion system compliance increased. The contributions to system compliance from syringes were significantly greater compared to those of extended infusion lines. In the occlusion alarm experiment, the occlusion alarm could be delayed by 69.76 ± 3.98 min for the 50-ml syringe with a 560 cm infusion line set-up. In conclusion, the compliance of a syringe pump system increases as the loaded syringe size, or the length of the infusion tubing increases. The occlusion alarm may be much delayed and not useful in highly compliant systems with respect to the potential occlusion of the infusion system, so more attention is required when using a highly compliant infusion system.

Renal injury from sevoflurane in noncardiac surgery: a retrospective cohort study.

BACKGROUND: Sevoflurane is metabolised into Compound A and fluoride that carry a hypothetical risk of nephrotoxicity. However, a clinically significant association between sevoflurane use and acute kidney injury (AKI) in humans has not been established. METHODS: We retrospectively reviewed 15 552 patients who underwent noncardiac surgery under general anaesthesia using a volatile agent lasting >3 h between July 2016 and May 2019 at a single centre. Patients were divided into a sevoflurane group or no sevoflurane group (desflurane or isoflurane). The primary outcome was incidence of postoperative AKI, which was defined based on the Kidney Disease: Improving Global Outcomes criteria using creatinine concentration within 48 h postoperatively. Propensity score analysis using inverse probability of treatment weighting and propensity score matching was designed to compare outcomes between groups. RESULTS: Amongst 13 701 included patients, 11 070 (80.8%) received sevoflurane during anaesthesia. The incidence of AKI was 2.3% (257/11 070) and 2.5% (66/2631) in the sevoflurane and no sevoflurane groups, respectvely (P=0.57). After inverse probability of treatment weighting adjustment, sevoflurane anaesthesia was not significantly associated with postoperative AKI (odds ratio [OR] 1.32; 95% confidence interval [CI]: 0.99-1.76; P=0.059). In the matched cohort, the incidence of AKI was 3.1% (81/2626) and 2.4% (62/2626) in the sevoflurane and no sevoflurane groups, respectively, and sevoflurane anaesthesia was not associated with postoperative AKI (OR 1.32; 95% CI: 0.94-1.86; P=0.11). CONCLUSIONS: Sevoflurane anaesthesia for >3 h was not associated with postoperative renal injury compared with anaesthesia using other volatile agents.

Comparison of two sizes of GlideScope® blades in tracheal intubation of infants: a randomised clinicaltrial.

BACKGROUND: The appropriate size of GlideScope® blade for tracheal intubation in neonates and premature infants has not been established. We evaluated the impact of the size of the GlideScope® blade on the time taken for intubation in infants weighing 2.5-3.6 kg. METHODS: Sixty infants weighing 2.5-3.6 kg were randomly assigned to use of the size 1 blade (n=30) or the size 2 blade (n=30). The primary outcome was the time taken to intubate. Components related to the laryngoscopic view which could affect the duration of the intubating process were also analysed. RESULTS: The time required for tracheal intubation was shorter with the size 2 blade than with the size 1 blade (16 [14-20] s vs 22 [18-25] s, P=0.002; median difference=-5; 95% confidence interval, -7 to -2). The rate at which the tip of the tracheal tube was located at the centre of the laryngeal inlet was higher with the size 2 blade than with the size 1 blade (83% vs 40%, P<0.001). Correlation analysis indicated that the time required to find the tip of the tube was related to how far the lower border of the arytenoid cartilages was located from the mid-horizontal line of the monitor (r=0.28, P=0.033). CONCLUSION: Use of the size 2 blade significantly reduced the time required to intubate the trachea, compared with the size 1 GlideScope® blade in infants. CLINICAL TRIAL REGISTRATION: KCT 0003867.

Simulation Analysis of Flow Rate Variability During Microinfusions: The Effect of Vertical Displacement and Multidrug Infusion in Conventional Infusion Pumps Versus New Cylinder-Type Infusion Pumps.

BACKGROUND: Medication dosing errors can occur during microinfusions when there is vertical pump displacement or multidrug infusion through a single intravenous path. We compared flow rate variability between new-generation cylinder-type infusion pumps and conventional infusion pumps under simulated conditions. METHODS: We evaluated the flow rates during microinfusions using different infusion pumps (syringe pump with 10/30/50-mL syringes, peristaltic pump, and cylinder pump). Two visible dyes were used as model drugs. The study samples were quantified using spectrophotometry. For vertical displacement, the infusion pumps were moved up and down by 60 cm during microinfusions at 0.5 mL·h-1 and 2 mL·h-1. In the multi-infusion study, the second drug flow was added through 4 linearly connected stopcocks either upstream or downstream of the first drug. We compared the total error dose between the cylinder pump and the syringe pump with a Mann-Whitney U test and additionally estimated the effects of the infusion pumps on total error doses by linear regression analysis. RESULTS: There were repetitive patterns of temporary flow increases when the pump was displaced upward and flow decreases when the pump was displaced downward in all settings. However, the amount of flow irregularities was more pronounced at the lower infusion rate and in the syringe-type pump using larger volume syringes. The total error dose increased in the syringe pump loaded with a 50-mL syringe compared to that of the new cylinder pump (regression coefficient [ß] = 4.66 [95% confidence interval {CI}, 1.60-7.72]; P = .008). The initiation and cessation of a new drug during multidrug microinfusion in the same intravenous path affected the lower rate first drug leading to a transient flow rate increase and decrease, respectively. The change in flow rate was observed regardless of the port selected for addition of the second drug, and the total error dose of the first drug did not significantly vary when an upstream or a downstream port was selected. CONCLUSIONS: In the microinfusion settings, attention must be paid to the use of the syringe pump loaded with large-volume syringes. The novel cylinder pump could be considered as a practical alternative to syringe pumps with small syringes given its flow stability without the need for frequent drug replacement.

Prognosis of Myocardial Injury After Non-Cardiac Surgery in Adults Aged Younger Than 45 Years.

BACKGROUND: This study compared myocardial injury after non-cardiac surgery (MINS) and mortalities between patients under and over the age of 45 years.Methods and Results:From January 2010 and June 2019, patients with cardiac troponin measurement within 30 days after non-cardiac surgery were enrolled and divided into groups according to age: >45 (≥45 years) and <45 (<45 years). Further analyses were conducted only in patients who were diagnosed with MINS. The outcomes were MINS and 30-day mortality. Of the 35,223 patients, 31,161 (88.5%) patients were in the >45-year group and 4,062 (11.5%) were in the <45-year group. After adjustment with inverse probability of weighting, the <45-years group showed a lower incidence of MINS and cardiovascular mortality (16.6% vs. 11.7%; odds ratio, 0.77; 95% confidence interval [CI], 0.69-0.84; P<0.001 and 0.4% vs. 0.2%; hazard ratio [HR], 0.41; 95% CI, 0.19-0.88; P=0.02, respectively). In a comparison of only the <45-years group, MINS was associated with increased 30-day mortality (0.7% vs. 10.3%; HR, 10.48; 95% CI, 6.18-17.78; P<0.001), but the mortalities of patients with MINS did not differ according to age. CONCLUSIONS: MINS has a comparable prognostic impact in patients aged under and over 45 years; therefore, future studies need to also consider patients aged <45 years regarding risk factors of MINS and screening of perioperative troponin elevation.

Association Between High Body Mass Index and Mortality Following Myocardial Injury After Noncardiac Surgery.

BACKGROUND: Despite an association between obesity and increased risks for various diseases, obesity has been paradoxically reported to correlate with improved mortality in patients with established cardiovascular disease. However, its effect has not been evaluated to date in patients with myocardial injury after noncardiac surgery (MINS). METHODS: From January 2010 to June 2019, of a total of 35,269 adult patients with postoperative cardiac troponin level data, 5633 (16.0%) patients had MINS as diagnosed by postoperative cardiac troponin I above the 99th-percentile upper reference of 40 ng·L-1 using the TnI-Ultra immunoassay. Patients with MINS were divided into 3 groups according to body mass index (BMI), with 3246 (57.6%) were in the normal (18.5-25 kg·m-2), 425 (7.5%) in the low BMI (<18.5 kg·m-2), and 1962 (34.8%) in the high BMI (≥25 kg·m-2) groups, respectively. The primary outcome was mortality during the first year after surgery, and the mortality during 30 days was also compared. RESULTS: Following adjustment for confounding with inverse probability of treatment weighting, mortality within the first year appeared to be significantly lower in the high BMI group compared with the normal (14.8% vs 20.9%; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.66-0.85; P < .001) and the low BMI (14.8% vs 25.6%; HR: 0.56; 95% CI, 0.48-0.66; P < .001) groups. CONCLUSIONS: High BMI may be associated with decreased mortality following MINS. Further investigations are needed to support this finding.

Elevated high-sensitivity C-reactive protein concentrations may be associated with increased postdischarge mortality in patients with myocardial injury after noncardiac surgery: A retrospective observational study.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is one of the most common cardiovascular complications associated with mortality and morbidity during the first 2 years after surgery. However, the relevant variables associated with mortality after discharge in patients with MINS have not been fully investigated. OBJECTIVES: This study aimed to evaluate the association between persistent inflammation detected by high-sensitivity C-reactive protein (hsCRP) at discharge and postdischarge mortality after MINS. DESIGN: Retrospective observational analysis of acquired data from Samsung Medical Center Troponin in Noncardiac Operation (SMC-TINCO) registry. SETTING: A tertiary hospital from January 2010 to June 2019. PATIENTS: Patients who were discharged alive after a diagnosis of MINS. MAIN OUTCOME MEASURES: The primary endpoint was postdischarge 1-year mortality, and 30-day mortality and the mortality from 30 days to 1 year was also compared. RESULTS: Data from a total of 4545 adult patients were divided into two groups according to hsCRP concentration at discharge. There were 757 (16.7%) patients in the normal hsCRP group and 3788 (83.3%) patients in the elevated hsCRP group. After inverse probability weighting, 1-year mortality was significantly higher in the elevated group than the normal group (hazard ratio 1.93, 95% CI 1.45 to 2.57, P  < 0.001). Thirty-day mortality and the mortality from 30 days to 1 year were also increased in the elevated group. CONCLUSION: In patients with MINS, an elevated hsCRP concentration at discharge appeared to be associated with increased mortality. Further research is needed to determine whether controlling inflammation can be helpful in reducing mortality.

Pre-operative anaemia and myocardial injury after noncardiac surgery: A retrospective study.

BACKGROUND: Pre-operative anaemia is associated with adverse outcomes of noncardiac surgery, but its association with myocardial injury after noncardiac surgery (MINS) has not been fully investigated. OBJECTIVE: The association between pre-operative anaemia and MINS. DESIGN: A single-centre retrospective cohort study. SETTING: Tertiary care referral centre. PATIENTS: Patients with measured cardiac troponin (cTn) I levels after noncardiac surgery. INTERVENTIONS: Patients were separated according to pre-operative anaemia (haemoglobin <13 g dl-1 in men and <12 g dl-1 in women). Anaemia was further stratified into mild and moderate-to-severe at a haemoglobin level threshold of 11 g dl-1. MAIN OUTCOME MEASURES: The primary outcome was MINS, defined as a peak cTn I level more than 99th percentile of the upper reference limit within 30 postoperative days. RESULTS: Data from a total of 35 170 patients were collected, including 22 062 (62.7%) patients in the normal group and 13 108 (37.3%) in the anaemia group. After propensity score matching, 11919 sets of patients were generated, and the incidence of MINS was significantly associated with anaemia [14.5 vs. 21.0%, odds ratio (OR) 1.57, 95% confidence interval (CI) 1.47 to 1.68, P < 0.001]. For the entire population, multivariable analysis showed a graded association between anaemia severity and MINS (OR 1.32, 95% CI 1.22 to 1.43, P < 0.001 for mild anaemia and OR 1.80, 95% CI 1.66 to 1.94, P < 0.001 for moderate-to-severe anaemia compared with the normal group) and a significantly higher incidence of MINS for moderate-to-severe anaemia than mild anaemia (18.6 vs. 28.6%, OR 1.37, 95% CI 1.25 to 1.50, P < 0.001). The estimated threshold for pre-operative haemoglobin associated with MINS was 12.2 g dl-1, with an area under the curve of 0.622. CONCLUSIONS: Pre-operative anaemia was independently associated with MINS, suggesting that MINS may be related to the association between anaemia and postoperative mortality. TRIAL REGISTRATION: SMC 2019-08-048.

Simulation study on flow rate accuracy of infusion pumps in vibration conditions during emergency patient transport.

Infusion pumps are frequently used when transferring critically ill patients via patient transport cart, ambulance, or helicopter. However, the performance of various infusion pumps under these circumstances has not been explored. The aim of this study was to evaluate the flow rate accuracy of infusion pumps under various clinical vibration conditions. Experiments were conducted with four different types of pumps, including two conventional syringe pumps (Injectomat MC Agilia, Fresenius Kabi and TE-331, Terumo), one conventional peristaltic pump (Volumed µVP7000; Arcomed), and one new cylinder pump (H-100, Meinntech). The flow rate was measured using an infusion pump analyzer on a stable table (0 m/s2) for 1 h with 1 ml/h and 5 ml/h. Experiments were repeated in mild vibration (2 m/s2) (representing vibration of patients in a moving stretcher or ambulance), and in moderate vibration (6 m/s2) (representing vibration in helicopter transport). Any accidental bolus occurrence in extreme vibration situations (20 m/s2) was also analyzed. Simulated vibrations were reproduced by a custom-made vibration table. In the resting state without vibration and in mild vibration conditions, all pumps maintained good performance. However, in moderate vibration, flow rates in syringe pumps increased beyond their known error ranges, while flow rates in peristaltic pumps remained stable. In extreme vibration, accidental fluid bolus occurred in syringe pumps but not in peristaltic pumps. The newly developed cylinder pump maintained stable performance and was unaffected by external vibration environments.

Effects of inspired oxygen concentration during emergence from general anaesthesia on postoperative lung impedance changes evaluated by electrical impedance tomography: a randomised controlled trial.

We evaluated the effects of three different inspired oxygen concentrations (40%, 80%, and 100%) at anaesthesia emergence on postoperative lung volumes as measured by global impedance of electrical impedance tomography (EIT). This is a randomised, controlled, and assessor-blinded study in single-centre from May 2017 to August 2017. Seventy-one patients undergoing elective laparoscopic colorectal surgery with healthy lung condition were randomly allocated into the three groups based on the concentration of inspired oxygen applied during anaesthesia emergence: 40%-, 80%- or 100%-oxygen. End-expiratory lung impedance (EELI) with normal tidal ventilation and total lung impedance (TLI) with full respiratory effort were measured preoperatively and before discharge in the post-anaesthesia care unit by EIT, and perioperative changes (the ratio of difference between preoperative and postoperative value to preoperative value) were compared among the three groups. Postoperative lung impedances were significantly reduced compared with preoperative values in all patients (P < 0.001); however, perioperative lung impedance reduction (%) did not differ among the three oxygen groups. The mean reduction ratio in each 40%-, 80%-, and 100%-oxygen group were 37% ± 13%, 41% ± 14%, and 46% ± 14% for EELI (P = 0.125) and 40% ± 20%, 44% ± 17% and 49% ± 20% for TLI (P = 0.276), respectively. Inspired oxygen concentrations applied during anaesthesia emergence did not show a significant difference in postoperative lung volume as measured by EIT in patients undergoing laparoscopic colorectal surgery with healthy lungs.Trial registration cris.nih.go.kr (KCT0002642).

The angle range of leg abduction with external hip rotation which can minimize femoral artery and vein overlap in pediatric patients.

BACKGROUND: Since the femoral artery frequently overlaps the femoral vein, femoral central venous catheterization carries the risk of arterial puncture in pediatric patients. AIMS: We evaluated the angle range of leg abduction with external hip rotation to minimize the overlap between the femoral artery and vein in pediatric patients undergoing general anesthesia. METHODS: Eighty-two pediatric patients who underwent elective surgery with general anesthesia were enrolled in this study. Using ultrasonography, patients were divided into groups N (patients with non-overlap) and O (patients with continuing overlap) based on the presence of non-overlap range between the femoral artery and vein. The range minimizing the overlap was defined as the range without overlap in group N and as the range presenting the overlap that was less-than-half of the radius of the femoral vein in group O. By increasing the angle of leg abduction with external hip rotation, the starting and ending angles minimizing the overlap were found using ultrasonographic images. RESULTS: The angle range of leg abduction with external hip rotation minimizing the overlap between the femoral artery and vein was defined as the range from the maximum 99% confidence interval of starting angles to the minimum 99% confidence interval of ending angles, which was between 45° and 65° in group N and between 48° and 58° in group O, respectively. CONCLUSION: Positioning patients in a range of 48° and 58° leg abduction with external hip rotation can minimize the overlap between the femoral artery and vein. However, the clinical usefulness of this positioning for femoral venous catheterization remains to be seen.

Comparison of Operator Workloads Associated with the Single-unit Anyfusion® Pump and the Changeover from a Syringe Pump to an Infusion Pump.

BACKGROUND: A changeover from a syringe pump to an infusion pump may transiently interrupt drug administration and result in medication errors. A newly developed infusion device (Anyfusion®) that combines the functions of an infusion pump and a syringe pump in a single unit was recently commercialized. This study compared the operator workloads associated with the Anyfusion® pump and with the conventional method using two infusion devices (a syringe pump and an infusion pump). METHODS: This was a prospective, randomized, crossover-designed simulation study using an imitation arm with an intravascular line. We compared the two methods in terms of total execution time, total number of button clicks, and subjective difficulty using a numerical rating scale with a score from 0 (extremely easy) to 10 (extremely difficult). RESULTS: Twenty-two nurses successfully performed both interventions according to the allocated sequence. Total execution times did not differ between the two methods (129.5 ± 23.2 seconds for the conventional method vs. 121.2 ± 24.3 seconds for the Anyfusion® method; P = 0.244), although the total number of clicks was significantly fewer using the Anyfusion® than the conventional method (median [interquartile range]: 10.0 [9.0-12.0] vs. 21.0 [20.0-25.0], respectively; P < 0.001). Participants rated the Anyfusion® method as easier than the conventional method (1.7 ± 1.2 vs. 3.6 ± 1.6; P < 0.001, respectively). CONCLUSION: The introduction of Anyfusion® lessened the workload of practitioners required by the changeover process, which might reduce the risk of medication errors and subsequent patient harm. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004172.

The effect of fluvastatin on cardiac fibrosis and angiotensin-converting enzyme-2 expression in glucose-controlled diabetic rat hearts.

Independently of the lipid-lowering effects, statin has been reported to attenuate the development of diabetic cardiomyopathy. However, the effect of statin in glucose-controlled diabetic condition has not been demonstrated. We evaluated the effect of fluvastatin on cardiac function, fibrosis, and angiotensin-converting enzyme-2 (ACE2) expression in glucose-controlled diabetic rats. Male Wistar rats were randomly divided into four groups: control (Group C), diabetes (Group D), diabetes with insulin (Group I), and diabetes with insulin and fluvastatin (Group I+F). Diabetes was induced by a single injection of streptozotocin (65 mg/kg). After 8 weeks, the hearts were extracted following echocardiographic evaluation. Cardiac fibrosis was analyzed using Masson's trichrome stain. Collagens I and III and ACE2 expressions were evaluated by immunohistochemistry and western blot. Group D showed reduced cardiac systolic function compared to the other groups (all P < 0.05). However, diastolic function estimated by E/A ratio was significantly decreased in groups D and I (median: 0.88 and 1.45, respectively) compared to groups C and I+F (2.97 and 2.15) (all P < 0.05). Cardiac fibrosis was more severe in groups D and I than in groups C and I+F (all P < 0.05) on Masson's trichrome stain. On immunohistochemistry, ACE2 expression was significantly decreased only in group D (all P < 0.05). However, collagen I and III showed higher expressions in group D compared to groups C and I+F while no significant difference was observed compared with group I (all P < 0.05). On western blot, collagen I and ACE2 expressions in group D (median: 1.78 and 0.35, respectively) were significantly different from groups C (references: 1) and I+F (0.76 and 1.21) (all P < 0.05), but not from group I (1.19 and 0.92). Our study suggested a combination of fluvastatin and insulin would be more effective than insulin alone in diabetic hearts. However, the exact mechanism remains to be elucidated.

Evaluation of augmented pulse pressure variation using the Valsalva manoeuvre as a predictor of fluid responsiveness under open-chest conditions: A prospective observational study.

BACKGROUND: Pulse pressure variation (PPV) is a well known dynamic preload indicator of fluid responsiveness. However, its usefulness in open-chest conditions remains controversial. OBJECTIVE: We evaluated whether augmented PPV during a Valsalva manoeuvre can predict fluid responsiveness after sternotomy. DESIGN: A prospective, observational study. SETTING: Single-centre trial, study period from October 2014 to June 2015. PATIENTS: Forty-nine adult patients who underwent off-pump coronary arterial bypass grafting. INTERVENTION: After midline sternotomy, haemodynamic parameters were measured before and after volume expansion (6 ml kg of crystalloids). PPV was calculated both automatically (PPVauto) and manually (PPVmanual). For PPV augmentation, we performed Valsalva manoeuvres with manual holding of the rebreathing bag and constant airway pressure of 30 cmH2O for 10 s before fluid loading and calculated PPV during the Valsalva manoeuvre (PPVVM). MAIN OUTCOME MEASURES: The predictive ability of PPVVM for fluid responsiveness using receiver-operating characteristic curve analysis. Responders were identified when an increase in cardiac index of at least 12% occurred after fluid loading. RESULTS: Twenty-one patients were responders and 28 were nonresponders. PPVVM successfully predicted fluid responsiveness with an area under the curve (AUC) of 0.88 [95% confidence interval (95% CI) 0.75 to 0.95; sensitivity 91%, specificity 79%, P < 0.0001] and a threshold value of 55%. Baseline PPVauto and PPVmanual also predicted fluid responsiveness [AUC 0.75 (0.62 to 0.88); sensitivity 79%, specificity 75%; and 0.76 (0.61 to 0.87]; sensitivity 71%, specificity 71%, respectively). However, only PPVVM showed a significant AUC-difference from that of central venous pressure (P = 0.008) and correlated with the change of cardiac index induced by volume expansion (r = 0.6, P < 0.001). CONCLUSION: Augmented PPV using a Valsalva manoeuvre can be used as a clinically reliable predictor of fluid responsiveness under open-chest condition. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02457572.

Utility of stroke volume variation measured using non-invasive bioreactance as a predictor of fluid responsiveness in the prone position.

The aim of this prospective study was to evaluate the usefulness of stroke volume variation (SVV) derived from NICOM® to predict fluid responsiveness in the prone position. Forty adult patients undergoing spinal surgery in the prone position were included in this study. We measured SVV from NICOM® (SVVNICOM) and FloTrac™/Vigileo™ systems (SVVVigileo), and pulse pressure variation (PPV) using automatic (PPVauto) and manual (PPVmanual) calculations at four time points including supine and prone positions, and before and after fluid loading of 6 ml kg-1 colloid solution. Fluid responsiveness was defined as an increase in the cardiac index from Vigileo™ of ≥12 %. There were 19 responders and 21 non-responders. Prone positioning induced a significant decrease in SVVNICOM, SVVVigileo, PPVauto, and PPVmanual. However, all of these parameters successfully predicted fluid responsiveness in the prone position with area under the receiver-operator characteristic curves for SVVNICOM, SVVVigileo, PPVauto, and PPVmanual of 0.78 [95 % confidence interval (CI) 0.62-0.90, P = 0.0001], 0.79 (95 % CI 0.63-0.90, P = 0.0001), 0.76 (95 % CI 0.6-0.88, P = 0.0006), and 0.84 (95 % CI 0.69-0.94, P < 0.0001), respectively. The optimal cut-off values were 12 % for SVVNICOM, SVVVigileo, and PPVauto, and 10 % for PPVmanual. SVV from NICOM® successfully predicts fluid responsiveness during surgery in the prone position. This totally non-invasive technique for assessing individual functional intravenous volume status would be useful in a wide range of surgeries performed in the prone position.

Effect of ramosetron on QTc interval: a randomised controlled trial in patients undergoing off-pump coronary artery bypass surgery.

BACKGROUND: Ramosetron is a relatively new 5-hydroxytryptamine three receptor antagonist with higher binding affinity and more prolonged duration of action compared to ondansetron. The present study was performed to evaluate the effects of ramosetron on QTc interval and possible cardiovascular adverse effects in patients undergoing cardiac surgery. METHOD: A total of 114 patients who underwent off-pump coronary artery bypass surgery were enrolled in this randomised placebo-controlled trial. Patients were allocated into two groups that received intravenous injection of 0.3 mg ramosetron or normal saline during induction of anaesthesia. QTc intervals were measured before the operation, intraoperatively (0, 1, 2, 3, 5, 10, 15, 30, 45, 60, 90, 120, and 240 min after injection of ramosetron or normal saline), at the end of the operation, and on postoperative day 1. RESULTS: There were no differences in mean QTc interval between groups at every time point. However, maximal change in QTc interval during surgery was higher in the ramosetron group than the placebo group (25.1 ± 22.0 vs. 17.5 ± 14.5 ms, 95 % CI 0.34-14.78, P = 0.040). Also, there were more patients with a QTc interval increase of > 60 ms in the ramosetron group (5 vs. 0, 95 % CI 1.6-18.0, P = 0.021). There were no significant differences in cardiovascular complications. CONCLUSIONS: Ramosetron administered during induction of anaesthesia may affect maximal change in QTc interval during off-pump coronary artery bypass surgery. Ramosetron should be used with caution in high risk patients for developing Torsades de Pointes. TRIAL REGISTRATION: ClinicalTrials.gov NCT02139241. Registered November 12, 2013.

Intraoperative anaphylaxis to neuromuscular blocking agents: the incidence over 9 years at two tertiary hospitals in South Korea: A retrospective observational study.

BACKGROUND: Intraoperative anaphylaxis to neuromuscular blocking agents (NMBAs) is a rare event that is unpredictable and potentially life threatening. Most of the previous reports on such intraoperative anaphylaxis used market share surveys or self-reported data to estimate the incidence. OBJECTIVE: To determine the incidences of intraoperative anaphylaxis to NMBAs using electronic medical records. DESIGN: A retrospective observational study. SETTING: Two tertiary hospitals in South Korea. PATIENTS: This study involved patients exposed to NMBAs during anaesthesia between 1 January 2005 and 31 May 2014. Nineteen episodes were deemed to be intraoperative anaphylaxis to NMBAs. MAIN OUTCOME MEASURES: We calculated the incidences of intraoperative anaphylaxis to NMBAs. Exposure to the agents was determined from intraoperative records maintained in an electronic medical recording system. An anaphylactic reaction was determined from both clinical signs and the results of skin tests. RESULTS: Over 9 years, 729 429 patients were exposed to NMBA, the most frequently used being rocuronium [425 047 (58.3%)] and vecuronium [274 801 (37.7%)]. The overall incidence of intraoperative anaphylaxis was 2.6 per 100 000 (19 cases), and was higher with rocuronium (16 cases, 3.8 per 100 000) than with vecuronium (two cases, 0.7 cases per 100 000), P = 0.014. Comparing the first 3 years with the last 6 years, the incidence of intraoperative rocuronium anaphylaxis appeared to increase 1.4-fold (P = 0.006). CONCLUSION: Among commonly used NMBAs, rocuronium appears to have the highest incidence of anaphylaxis. Our findings suggest that future prospective investigation for NMBA-induced anaphylaxis should use internationally agreed skin test protocols.

Tissue microcirculation measured by vascular occlusion test during anesthesia induction.

Tissue microcirculation measured by vascular occlusion test is impaired during septic shock. However, it has not been investigated extensively during anesthesia induction. The aim of the study is to evaluate tissue microcirculation during anesthesia induction. We hypothesized that during anesthesia induction, tissue microcirculation measured by vascular occlusion test might be enhanced with peripheral vasodilation during anesthesia induction. We conducted a prospective observational study of 50 adult patients undergoing cardiac surgery. During anesthesia induction, we measured and analyzed tissue oxygen saturation, vascular occlusion test, cerebral oximetry, forearm-minus-fingertip skin temperature gradients and hemodynamic data in order to evaluate microcirculation as related to alterations in peripheral vasodilation as reflected by increased Tforearm-finger thermal gradients. During anesthesia induction, recovery slope during vascular occlusion test and cerebral oxygen saturation increased from 4.0 (1.5) to 4.7 (1.3) % s(-1) (p = 0.02) and 64.0 (10.2) to 74.2 (9.2) % (p < 0.001), respectively. Forearm-minus-fingertip skin temperature gradients decreased from 1.9 (2.9) to -1.4 (2.2) °C (p < 0.001). There was an inverse correlation between changes in the skin temperature gradients and changes in cerebral oximetry (r = 0.33; p = 0.02). During anesthesia induction, blood pressure and forearm-minus-fingertip skin temperature gradients decrease while cerebral oximetry and vascular occlusion test recovery slope increase. These findings suggest that anesthesia induction increases tissue microcirculation with peripheral vasodilation.