Amino acids to prevent cardiac surgery-associated acute kidney injury: a randomized controlled trial.

BACKGROUND: This study aimed to examine the preventive effect of amino acids on postoperative acute kidney injury (AKI). METHODS: This was single-center, patient- and assessor-blinded, randomized controlled trial. Patients who underwent aortic surgery with cardiopulmonary bypass were included. The intervention group received 60 g/day of amino acids for up to 3 days. The control group received standard care. The primary outcome was the incidence of AKI. We assessed the effect of amino acids on AKI using a Cox proportional hazards regression model. RESULTS: Sixty-six patients were randomly assigned to the control or intervention group. One patient in the control group withdrew consent after randomization. The incidence of AKI was 10 patients (30.3%) in the intervention group versus 18 patients (56.2%) in the control group (adjusted hazard ratio, 0.44; 95% confidence interval, 0.20-0.95; P = 0.04). CONCLUSIONS: This trial demonstrated a significant reduction in AKI incidence with amino acid supplementation. TRIAL REGISTRATION: jRCT, jRCTs051210154. Registered 31 December 2021, https://jrct.niph.go.jp/re/reports/detail/69916.

Association between intraoperative blood salvage and coagulation disorder after cardiopulmonary bypass.

BACKGROUND: This study investigated whether intraoperative blood salvage was associated with coagulation disorder diagnosed by conventional coagulation tests and thromboelastography (TEG) after cardiopulmonary bypass (CPB). STUDY DESIGN AND METHODS: This was a prospective, observational study. Ninety-two patients who underwent cardiovascular surgery with CPB were enrolled. We evaluated coagulation function in patients with or without cell salvage blood transfusion at the following time points: before CPB, just after protamine administration, and 1 h after protamine administration. We evaluated platelet count, fibrinogen concentration, and TEG parameters. Patients were considered to have coagulation disorder if one or more of the following criteria were present: (1) residual heparin, (2) low platelet count, (3) low fibrinogen level, (4) low clotting factor level, and (5) hyperfibrinolysis. RESULTS: Fifty-three of 92 patients (57.6%) received intraoperative cell salvage. Coagulation disorder was observed in 56 of 92 patients (60.9%) after CPB. There was no significant difference between patients with or without intraoperative blood salvage in terms of the incidence of coagulation disorder (p = 0.542) or the total volume of blood from the drain after CPB (p = 0.437). Intraoperative blood salvage was not associated with coagulation disorder diagnosed by either TEG or conventional coagulation tests (odds ratio 1.329, 95% confidence interval: 0.549-3.213, p = 0.547). There were no significant interactions between patients with or without intraoperative blood salvage regarding coagulation parameters derived from TEG. CONCLUSIONS: The incidence of coagulation disorder and the total blood volume from the drain after CPB did not differ significantly between patients with or without intraoperative blood salvage.

Effect of cerebrospinal fluid drainage pressure in descending and thoracoabdominal aortic repair: a prospective multicenter observational study.

PURPOSE: Cerebrospinal fluid drainage (CSFD) is recommended during open or endovascular thoracic aortic repair. However, the incidence of CSFD complications is still high. Recently, CSF pressure has been kept high to avoid complications, but the efficacy of CSFD at higher pressures has not been confirmed. We hypothesize that CSFD at higher pressures is effective for preventing motor deficits. METHODS: This prospective observational study included 14 hospitals that are members of the Japanese Society of Cardiovascular Anesthesiologists. Patients who underwent thoracic and thoracoabdominal aortic repair were divided into four groups: Group 1, CSF pressure around 10 mmHg; Group 2, CSF pressure around 15 mmHg; Group 3, CSFD initiated when motor evoked potential amplitudes decreased; and Group 4, no CSFD. We assessed the association between the CSFD group and motor deficits using mixed-effects logistic regression with a random intercept for the institution. RESULTS: Of 1072 patients in the study, 84 patients (open surgery, 51; thoracic endovascular aortic repair, 33) had motor deficits at discharge. Groups 1 and 2 were not associated with motor deficits (Group 1, odds ratio (OR): 1.53, 95% confidence interval (95% CI): 0.71-3.29, p = 0.276; Group 2, OR: 1.73, 95% CI: 0.62-4.82) when compared with Group 4. Group 3 was significantly more prone to motor deficits than Group 4 (OR: 2.56, 95% CI: 1.27-5.17, p = 0.009). CONCLUSION: CSFD is not associated with motor deficits in thoracic and thoracoabdominal aortic repair with CSF pressure around 10 or 15 mmHg.

Quantitative regional cerebral blood flow measurement using near-infrared spectroscopy and indocyanine green in patients undergoing superficial temporal to middle cerebral artery bypass for moyamoya disease: a novel method using a frequency filter.

Measuring regional cerebral blood flow (rCBF) after revascularization for moyamoya disease, as a type of ischemic cerebrovascular disease, is crucial. This study aims to validate our novel technology that combines near-infrared spectroscopy (NIRS) with a frequency filter to extract the arterial component. We measured rCBF before and after revascularization for moyamoya disease and at the end of the surgery using NIRO-200NX (Hamamatsu Photonics, Japan) and indocyanine green (ICG). rCBF was calculated using Fick's principle, change in arterial ICG concentrations, and maximum arterial ICG concentration. rCBF measured with NIRS (rCBF_N) was compared with pre- and postoperative rCBF measured with SPECT (rCBF_S). Thirty-four procedures were analyzed. rCBF_N increased from baseline to end of the surgery (mean difference (MD), 2.99 ml/min/100 g; 95% confidence interval (CI), 0.40-5.57 ml/min/100 g on the diseased side; MD, 4.94 ml/min/100 g; 95% CI, 2.35-7.52 ml/min/100 g on the non-diseased side). Similar trends were observed for rCBF_S (MD, 3.98 ml/min/100 g; 95% CI, 2.30-5.67 ml/min/100 g on the diseased side; MD, 2.77 ml/min/100 g; 95% CI, 1.09-4.45 ml/min/100 g on the non-diseased side). Intraclass correlations 3 (ICC3s) between rCBF_N and rCBF_S were weak on the diseased side (ICC3, 0.25; 95% CI, -0.03-0.5; p = 0.07) and the non-diseased side (ICC3, 0.24; 95% CI, -0.05-0.5; p = 0.08). rCBF measurements based on this novel method were weakly correlated with rCBF measurements with SPECT.

Monitoring of Post-Brain Injuries By Measuring Plasma Levels of Neuron-Derived Extracellular Vesicles.

Background: Extracellular vesicles (EV) released from neurons into the blood can reflect the state of nervous tissue. Measurement of neuron derived EV (NDE) may serve as an indicator of brain injury. Methods: A sandwich immunoassay was established to measure plasma NDE using anti-neuron CD171 and anti-EV CD9 ([CD171 + CD9+]). Plasma samples were obtained from commercial sources, cross-country (n = 9), football (n = 22), soccer (n = 19), and rugby (n = 18) athletes over time. Plasma was also collected from patients undergoing total aortic arch replacement (TAR) with selective cerebral perfusion during cardiopulmonary bypass before and after surgery (n = 36). Results: The specificity, linearity, and reproducibility of NDE assay (measurement of [CD171 + CD9+]) were confirmed. By scanning electron microscopy and nanoparticle tracking, spherical vesicles ranging in size from 150 to 300 nm were confirmed. Plasma levels of NDE were widely spread over 2 to 3 logs in different individuals with a significant age-dependent decrease. However, NDE were very stable in each individual within a ± 50% change over time (cross-country, football, soccer), whereas rugby players were more variable over 4 years. In patients undergoing TAR, NDE increased rapidly in days post-surgery and were significantly (P = .0004) higher in those developing postoperative delirium (POD) (n = 13) than non-delirium patients (n = 23). Conclusions: The blood test to determine plasma levels of NDE was established by a sandwich immunoassay using 2 antibodies against neuron (CD171) and exosomes (CD9). NDE levels varied widely in different individuals and decreased with age, indicating that NDE levels should be considered as a normalizer of NDE biomarker studies. However, NDE levels were stable over time in each individual, and increased rapidly after TAR with greater increases associated with patients developing POD. This assay may serve as a surrogate for evaluating and monitoring brain injuries.

Novel brain computed tomography perfusion for cerebral malperfusion secondary to acute type A aortic dissection.

OBJECTIVES: The management of acute type A aortic dissection with malperfusion syndrome remains challenging. To evaluate preoperative condition, symptoms might be subjective and objective evaluation of cerebral artery has not yet been established. For quantitative evaluation, this study focused on brain computed tomography perfusion (CTP), which has been recommended by several guidelines of acute ischaemic stroke. METHODS: In the last 2 years, 147 patients hospitalized due to acute type A aortic dissection were retrospectively reviewed. Among the 23 (16%) patients with cerebral malperfusion, 14 who underwent brain CTP (6 preoperative and 8 postoperative) were enrolled. CTP parameters, including regional blood flow and time to maximum, were automatically computed using RApid processing of Perfusion and Diffusion software. The median duration from the onset to hospital arrival was 129 (31-659) min. RESULTS: Among the 6 patients who underwent preoperative CTP, 4 with salvageable ischaemic lesion (penumbra: 8-735 ml) without massive irreversible ischaemic lesion (ischaemic core: 0-31 ml) achieved acceptable neurological outcomes after emergency aortic replacement regardless of preoperative neurological severity. In contrast, 2 patients with an ischaemic core of >50 ml (73, 51 ml) fell into a vegetative state or neurological death due to intracranial haemorrhage. CTP parameters guided postoperative blood pressure augmentation without additional supra-aortic vessel intervention in the 8 patients who underwent postoperative CTP, among whom 6 achieved normal neurological function regardless of common carotid true lumen stenosis severity. CONCLUSIONS: CTP was able to detect irreversible ischaemic core, guide critical decisions in preoperative patients and aid in determining the blood pressure augmentation for postoperative management focusing on residual brain ischaemia.

Cardiac surgery improves the postoperative frailty score of frail patients.

BACKGROUND: Cardiac surgery in frail patients has been reported to be associated with increased mortality and morbidity but may improve functional status of frail patients. Few studies have investigated the impact of cardiac surgery on the trajectory of postoperative frailty. We hypothesized that cardiac surgery in frail patients would improve frailty postoperatively. METHOD: This study included 71 patients over 65 years old who were scheduled for cardiac surgery via sternotomy or thoracotomy. Frailty was prospectively evaluated using the Kihon Checklist (KCL) at 1 and 3 months postoperatively. Patients were divided into three groups based on the preoperative KCL score: nonfrail, prefrail, and frail. The interaction between the degree of preoperative frailty and the trajectory of postoperative KCL scores was assessed. RESULTS: The KCL score changed significantly over time (P < 0.001), and the KCL score trajectory differed significantly according to the degree of preoperative frailty (P for interaction = 0.003). In the frail group, the KCL score was significantly lower 3 months postoperatively than preoperatively (median 8, interquartile range [5, 9] versus median 9, interquartile range (9, 13), P = 0.029). CONCLUSION: The trajectory of postoperative KCL scores differed significantly depending on the degree of preoperative frailty. At 3 months after cardiac surgery, the KCL score of frail patients was significantly improved, while that in nonfrail patients was significantly deteriorated.

Association Between Sternotomy Versus Thoracotomy and the Prevalence and Severity of Chronic Postsurgical Pain After Mitral Valve Repair: An Observational Cohort Study.

OBJECTIVE: Investigate differences in the prevalence and severity of chronic postsurgical pain (CPSP) after cardiac surgery via thoracotomy versus sternotomy are not well-understood. DESIGN: An observational cohort study. SETTING: A tertiary care hospital. PARTICIPANTS: Four hundred twenty-eight patients (sternotomy: 192 patients, thoracotomy: 236 patients) who underwent mitral valve repair. INTERVENTIONS: A questionnaire about the severity of surgical wound pain evaluated with a numerical rating scale (NRS) was sent. NRS responses for current pain, peak pain in the last four weeks, and average pain in the last four weeks were evaluated. MEASUREMENTS AND MAIN RESULTS: The main outcomes were the severity of CPSP evaluated using NRS and the prevalence of CPSP. CPSP was defined as pain >0 that developed after a surgical procedure. During the median follow-up of 29 months, 79 patients complained of CPSP. (sternotomy: 15 patients, thoracotomy: 64 patients). Multivariate ordinal logistic regression showed that NRS responses for current pain (adjusted odds ratio [aOR], 3.17; 95% confidence interval [CI] 1.64-6.12; p = 0.001), peak pain in the last four weeks (aOR, 2.00; 95% CI 1.11-3.61; p = 0.021), and average pain in the last four weeks (aOR, 2.21; 95% CI 1.31-3.72; p = 0.003) were significantly higher in patients who underwent thoracotomy. Multivariate logistic regression showed that thoracotomy was an independent predictor of CPSP (aOR, 3.63; 95% CI 1.67-7.88; p = 0.001). CONCLUSIONS: The prevalence and severity of CPSP were higher among patients who underwent mitral valve repair via thoracotomy than sternotomy.

Cerebrospinal fluid drainage to prevent postoperative spinal cord injury in thoracic aortic repair.

BACKGROUND: Cerebrospinal fluid drainage (CSFD) is recommended as a spinal cord protective strategy in open and endovascular thoracic aortic repair. Although small studies support the use of CSFD, systematic reviews have not suggested definite conclusion and a large-scale study is needed. Therefore, we reviewed medical records of patients who had undergone descending and thoracoabdominal aortic repair (both open and endovascular repair) at multiple institutions to assess the association between CSFD and postoperative motor deficits. METHODS: Patients included in this study underwent descending or thoracoabdominal aortic repair between 2000 and 2013 at 12 hospitals belonging to the Japanese Association of Spinal Cord Protection in Aortic Surgery. We conducted a retrospective study to investigate whether motor-evoked potential monitoring is effective in reducing motor deficits in thoracic aortic aneurysm repair. We use the same dataset to examine whether CSFD reduces motor deficits after propensity score matching. RESULTS: We reviewed data from 1214 patients [open surgery, 601 (49.5%); endovascular repair, 613 (50.5%)]. CSFD was performed in 417 patients and not performed in the remaining 797 patients. Postoperative motor deficits were observed in 75 (6.2%) patients at discharge. After propensity score matching (n = 700), mixed-effects logistic regression performed revealed that CSFD is associated with postoperative motor deficits at discharge [adjusted odds ratio (OR), 3.87; 95% confidence interval (CI), 2.30-6.51]. CONCLUSION: CSFD may not be effective for postoperative motor deficits at discharge.

U-Shaped Association Between Intraoperative Net Fluid Balance and Risk of Postoperative Recurrent Atrial Tachyarrhythmia Among Patients Undergoing the Cryo-Maze Procedure: An Observational Study.

OBJECTIVE: The ability of perioperative fluid management to prevent postoperative recurrence of atrial tachyarrhythmia remains controversial. The aim of the present study was to assess if intraoperative net fluid balance was associated with atrial tachyarrhythmia recurrence after the Cryo-Maze procedure. DESIGN: An observational cohort study. SETTING: A tertiary care hospital from April 2007 to May 2019. PARTICIPANTS: Four hundred forty-four patients undergoing the Cryo-Maze procedure in conjunction with other cardiac surgeries. INTERVENTIONS: The Cryo-Maze procedure in conjunction with other cardiac surgeries. MEASUREMENTS AND MAIN RESULTS: The main outcome was early atrial tachyarrhythmia recurrence, consisting of atrial fibrillation, atrial flutter, or atrial tachycardia, within the first three months after surgery. Complete follow-up was achieved in 443 patients (99.8%), of them 127 (28.6%) developed early atrial tachyarrhythmia recurrence. The median intraoperative net fluid balance was 1,627 mL (interquartile range, -215 to 3,557 mL). Multivariate logistic regression showed that intraoperative net fluid balance (p = 0.001), preoperative AF duration (adjusted odds ratio, 1.40; 95% CI, 1.17-1.68; p < 0.001) and left atrial volume index (aOR, 1.61; 95% CI, 1.06-2.45; p = 0.025) were independent predictors of early atrial tachyarrhythmia recurrence. The adjusted log odds were lowest (-1.52) when net fluid balance was 1,557 mL. CONCLUSIONS: There is a significant U-shaped association between intraoperative net fluid balance and early atrial tachyarrhythmia recurrence among patients undergoing the Cryo-Maze procedure.

Association between postoperative changes in the gut microbiota and pseudopsia after cardiac surgery: prospective observational study.

BACKGROUND: Delirium after cardiac surgery affects mortality, but the mechanism remains unclear. Previous studies have reported gut microbiota are associated with brain activity. Systemic inflammation and antibiotics can damage the gut microbiota after cardiac surgery. We aimed to investigate changes in the gut microbiota and the association between the gut microbiota and delirium after cardiac surgery. METHODS: Twenty-one patients who underwent cardiac surgery were enrolled. Microbiota counts and fecal organic acid concentrations were measured in fecal samples harvested before surgery, just after surgery, and before discharge. To quantify the microbiota, we extracted total RNA fractions and examined gut microbiota composition using 16S and 23S rRNA-targeted quantitative-reverse Transcription-PCR. Postoperative delirium, insomnia, and pseudopsia were assessed for 1 week. Postoperative total bacterial counts changed significantly from 10.2 ± 0.2 log10 cells/g of feces to 9.8 ± 0.5 in the first postoperative samples (p = 0.003) and 10.0 ± 0.4 in the samples before discharge (p = 0.039). Fecal pH was 6.9 ± 0.6 before surgery and 7.4 ± 0.7 in the first postoperative samples (p = 0.001). Postoperative Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia than in patients without pseudopsia (3.2 ± 1.3 vs. 5.4 ± 0.9; p = 0.012 and 1.7 ± 0.8 vs. 4.6 ± 2.7; p = 0.001). CONCLUSIONS: Total bacterial counts were significantly lower after surgery and until discharge. Fecal pH was significantly higher than preoperative levels. Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia.

Transesophageal echocardiography in robot-assisted mitral valve repair for Barlow's disease: usefulness for predicting artificial ring size and artificial chordae length using the loop technique.

BACKGROUND: There is no fully recommended methodology for surgery for Barlow's disease. Various methods have been proposed. The aim of this study was to investigate the effectiveness of transesophageal echocardiography (TEE) measurements for selecting the optimal annuloplasty ring size and determining the length of artificial chordae in patients with Barlow's disease who underwent robot-assisted mitral valvuloplasty (R-MVP). METHODS: Ten patients were included. Before R-MVP, the anesthesiologist used TEE to predict the optimal annuloplasty ring size and artificial chordae lengths that would reduce mitral regurgitation. The anesthesiolosist's predict ring size was not presented to the surgeon intraoperatively. RESULTS: In 70% (7/10) of cases, the surgeon performed mitral valve repair in full match with the anesthesiologist's repair plan. Mitral regurgitation was controlled in 85% (6/7) of cases. In three cases, the predict annuloplasty ring size and artificial chordae length were not match between anesthesiologist and surgeon. After the operation, 90% (9/10) of patients had no residual mitral regurgitation. CONCLUSIONS: Anesthesiologist's TEE measurements were useful for selecting the optimal annuloplasty ring size and artificial chordae length during R-MVP. TEE can play an important role in robot-assisted, minimally invasive cardiac surgery for mitral regurgitation with extensive and complex prolapse, such as in Barlow's disease.

Transfusion characteristics and hemostatic conditions in octogenarians undergoing emergency surgery for acute aortic dissection: a retrospective study.

BACKGROUND: The number of elderly patients undergoing elective as well as emergent cardiac surgery is increasing. Octogenarian and older patients undergoing surgery for acute type A aortic dissection (AAD) have a significantly higher risk of postoperative mortality than younger patients. Hemostasis is difficult in octogenarians with AAD. However, few studies have investigated perioperative blood transfusion volumes and hemostatic conditions in patients undergoing AAD surgery. We retrospectively investigated whether these factors differed between octogenarians and younger patients with AAD. METHODS: The records of 207 patients who underwent emergency surgery for AAD were reviewed between 2008 and 2014. We compared the total volumes of transfused blood components (red blood cell concentrate, fresh frozen plasma, platelets concentrate, and cryoprecipitate), perioperative blood coagulation test results (prothrombin time-international normalized ratio, activated partial thrombin time, and activated coagulation time), and intensive care unit and hospital stay durations between octogenarians (n = 33) and patients < 80 years old (n = 170). RESULTS: A significantly greater volume of red blood cell concentrates was transfused in octogenarians than in patients < 80 years old. Isolated prolonged activated partial thromboplastin time was observed in octogenarian patients. Duration of hospital stays was significantly longer in octogenarians than in patients < 80 years old. CONCLUSIONS: Octogenarians required more red blood cells during surgery for AAD and exhibited isolated APTT prolongation.

Comparison of Right Ventricular Function Between Patients With and Without Pulmonary Hypertension Owing to Left-Sided Heart Disease: Assessment Based on Right Ventricular Pressure-Volume Curves.

OBJECTIVES: Right ventricular (RV) failure with pulmonary hypertension (PH) is frequently encountered in patients with advanced left-sided heart disease (LHD). However, RV energetics in patients with postcapillary PH because of LHD has not been well studied. The authors investigated intraoperative RV energetics in patients with PH due to LHD based on pressure-volume curves with three-dimensional transesophageal echocardiography and pulmonary artery catheterization. DESIGN: Exploratory study. SETTING: National center. PARTICIPANTS: Thirty-three patients who underwent cardiac surgery for LHD were enrolled. Ten patients had PH (mean pulmonary artery pressure ≥ 25 mmHg). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: RV stroke work index (RVSWI) was calculated by integrating the area bounded by the pressure-volume curve. RV minute work index (RVMWI) was calculated as RVSWI × heart rate. Right ventriculo-arterial coupling was estimated as stroke volume divided by end-systolic volume (SV/ESV). The authors compared RV energetics between patients with and without PH because of LHD. RVSWI and RVMWI were significantly higher in patients with PH (690.7 mmHg·mL/m2 [601.6-737.1] v 440.9 mmHg·mL/m2 [330.8-585.3], p = 0.015, and 60,068 mmHg·mL/m2/min [35,547-68,741] v 26,351 mmHg·mL/m2/min [17,316-32,517], p = 0.011, respectively), although cardiac index was nearly identical. SV/ESV was significantly lower in patients with PH (0.520 [0.305-0.810] v 0.820 (0.650-1.090), p = 0.007). CONCLUSIONS: Although cardiac index was similar, RVSWI and RVMWI were significantly higher and SV/ESV was significantly lower in patients with PH because of LHD, suggesting that patients with postcapillary PH have inefficient RV performance.

Transient Neurological Events After Surgery for Pediatric Moyamoya Disease: A Retrospective Study of Postoperative Sedation Practices.

BACKGROUND: Moyamoya disease is a cerebrovascular disease characterized by bilateral stenosis of the intracranial internal carotid arteries and an abnormal collateral vascular network at the base of the brain. Transient neurological events (TNEs), which are episodes of neurological dysfunction lasting <24 hours, are associated with stroke in pediatric patients with Moyamoya disease. Perioperative agitation often occurs in pediatric patients. We hypothesized that anesthetic technique and postoperative sedation would modify the association between TNE and superficial temporal artery-middle cerebral artery (STA-MCA) bypass in pediatric patients with Moyamoya disease. METHODS: We retrospectively reviewed the medical records of patients with Moyamoya disease aged 15 years and below who underwent STA-MCA bypass under general anesthesia at a single cerebrovascular center in Japan between January 1999 and March 2016. The primary outcome was TNE. Mixed-effects logistic regression was used to evaluate whether postoperative sedation and anesthetic agents were associated with TNE. RESULTS: Among 277 hemispheres in 154 pediatric patients who underwent STA-MCA bypass, 107 patients (39%) experienced TNE within 1 week after surgery. Crying (adjusted odds ratio, 3.11; 95% confidence interval, 1.01-9.59; P=0.048) was an independent risk factor for TNE. Postoperative sedation was associated with a lower incidence of TNE (adjusted odds ratio, 0.514; 95% confidence interval, 0.264-0.997; P=0.049), but premedication and anesthetic agents were not associated with TNE. CONCLUSION: In pediatric patients with Moyamoya disease, crying was associated with increased TNE and postoperative sedation is associated with decreased TNE.

A practical guide for anesthetic management during intraoperative motor evoked potential monitoring.

Postoperative motor dysfunction can develop after spinal surgery, neurosurgery and aortic surgery, in which there is a risk of injury of motor pathway. In order to prevent such devastating complication, intraoperative monitoring of motor evoked potentials (MEP) has been conducted. However, to prevent postoperative motor dysfunction, proper understanding of MEP monitoring and proper anesthetic managements are required. Especially, a variety of anesthetics and neuromuscular blocking agent are known to attenuate MEP responses. In addition to the selection of anesthetic regime to record the baseline and control MEP, the measures to keep the level of hypnosis and muscular relaxation at constant are crucial to detect the changes of MEP responses after the surgical manipulation. Once the changes of MEP are observed based on the institutional alarm criteria, multidisciplinary team members should share the results of MEP monitoring and respond to check the status of monitoring and recover the possible motor nerve injury. Prevention of MEP-related adverse effects is also important to be considered. The Working Group of Japanese Society of Anesthesiologists (JSA) developed this practical guide aimed to help ensure safe and successful surgery through appropriate anesthetic management during intraoperative MEP monitoring.

Type and Size of Implanted Bioprosthetic Valve Rather Than Intraoperative Peak Transprosthetic Valvular Velocity Predict Postoperative Midterm Prosthesis-Patient Mismatch in Patients Undergoing Surgical Aortic Valve Replacement.

OBJECTIVES: High transprosthetic valvular peak velocity (PV) is indicative of prosthesis-patient mismatch (PPM), which exacerbates mortality and morbidity after surgical aortic valve replacement (AVR). During surgical AVR, a high intraoperative PV sometimes is detected, but whether it affects mortality and morbidity is unknown. The aims of this study were to determine whether intraoperative and postoperative PV were correlated and what factors predicted postoperative PPM. DESIGN: Retrospective, observational, cohort study. SETTING: Tertiary medical center. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study comprised 556 patients who underwent AVR with a bioprosthetic valve. PV was measured intraoperatively, 1 month after surgery, and 1 year after surgery. The occurrence of PPM was defined as an effective orifice area index of less than 0.85 cm2/m2. The associations between PV values at the aforementioned 3 time points were analyzed using a multivariable nonlinear regression model. A multivariable logistic regression model was used to identify the predictors of PPM at 1 year. There was no significant association between intraoperative PV and PV at 1 month (p = 0.419) or 1 year (p = 0.115). The implanted valve type (p < 0.001) and size (p < 0.001), but not intraoperative PV (p = 0.503), were independent predictors of PPM. CONCLUSIONS: There was no significant association between intraoperative and postoperative PV values. Implanted valve type and size, but not intraoperative PV, predicted postoperative PPM.

Guidelines for the use of cerebral oximetry by near-infrared spectroscopy in cardiovascular anesthesia: a report by the cerebrospinal Division of the Academic Committee of the Japanese Society of Cardiovascular Anesthesiologists (JSCVA).

Cerebral Oximetry by Near-infrared Spectroscopy (NIRS) has been used in cardiovascular anesthesia, but there was no guideline of regional cerebral oxygen saturation measured by cerebral oximetry by NIRS. This guideline provides recommendations applicable to patients at a risk of developing cerebral ischemia in cardiovascular surgery. Guidelines are intended to define practices meeting the needs of patients in most, but not all, circumstances, and should not replace clinical judgment. The Japanese Society of Cardiovascular Anesthesiologists (JSCVA) Task Force on Guidelines make an effort to ensure that the guideline writing committee contains broad views in using cerebral oximetry. Adherence to recommendations could be enhanced by shared decision making between healthcare providers and patients. This guideline was focused on cerebral oximetry of pediatric and adult cardiovascular disease. We hope this guideline would play an important role in using cerebral oximetry by measured NIRS.

Association Between Motor-Evoked Potentials and Spinal Cord Damage Diagnosed With Magnetic Resonance Imaging After Thoracoabdominal and Descending Aortic Aneurysm Repair.

OBJECTIVES: The authors investigated the association between intraoperative motor-evoked potential (MEP) changes and the severity of spinal cord infarction diagnosed with magnetic resonance imaging (MRI) to clarify the discrepancy between them, which was observed in patients with postoperative motor deficits after thoracic and thoracoabdominal aortic surgery. DESIGN: A multicenter retrospective study. SETTING: Motor-evoked potential <25% of control values was deemed positive for spinal cord ischemia. The severity of spinal cord infarction was categorized into grades A to D based on previous studies using the most severe axial MRI slices. The associations between MRI grade, MEP changes, and motor deficits were examined using logistic regression. PARTICIPANTS: Twenty-three of 1,245 patients (from 1999 to 2013, at 12 hospitals in Japan) were extracted from medical records of patients who underwent thoracic and thoracoabdominal aortic repair, with intraoperative MEP examinations and postoperative spinal MRI. INTERVENTIONS: No intervention (observational study). MEASUREMENTS AND MAIN RESULTS: Motor-evoked potential <25% of control value was associated significantly with motor deficits at discharge (adjusted odds ratio [OR], 130.0; p = 0.041), but not with severity of spinal cord infarction (adjusted OR, 0.917; p = 0.931). Motor deficit at discharge was associated with severe spinal cord infarction (adjusted OR, 4.83; p = 0.043), MEP <25% (adjusted OR, 13.95; p = 0.031), and combined deficits (motor and sensory, motor and bowel or bladder, or sensory and bowel or bladder deficits; adjusted OR, 31.03; p = 0.072) in stepwise logistic regression analysis. CONCLUSION: Motor-evoked potential <25% was associated significantly with motor deficits at discharge, but not with the severity of spinal cord infarction.