Development of extended pharmacokinetic models for propofol based on measured blood and brain concentrations.

Propofol's pharmacokinetics have been extensively studied using human blood samples and applied to target-controlled infusion systems; however, information on its concentration in the brain remains scarce. Therefore, this study aimed to simultaneously measure propofol plasma and brain concentrations in patients who underwent awake craniotomy and establish new pharmacokinetic model. Fifty-seven patients with brain tumors or brain lesions who underwent awake craniotomy were sequentially assigned to model-building and validating groups. Plasma and brain (lobectomy or uncapping margins) samples were collected at five time-points. The concentration of propofol was measured using high-performance liquid chromatography. Population pharmacokinetic analysis was conducted through a nonlinear mixed-effects modeling program using a first-order conditional estimation method with interactions. Propofol's brain concentrations were higher than its plasma concentrations. The measured brain concentrations were higher than the effect site concentrations using the previous models. Extended models were constructed based on measured concentrations by incorporating the brain/plasma partition coefficient (Kp value). Extended models showed good predictive accuracy for brain concentrations in the validating group. The Kp value functioned as a factor explaining retention in the brain. Our new pharmacokinetic models and Kp value can predict propofol's brain and plasma concentrations, contributing to safer and more stable anesthesia.

Remimazolam in perioperative management of Eisenmenger syndrome: a case report.

BACKGROUND: Eisenmenger syndrome (ES) is characterized by severe and irreversible pulmonary hypertension stemming from an uncorrected intracardiac shunt of significant size. The imbalance between systemic and pulmonary artery pressures predisposes patients with ES to the risk of cardiac arrest. Remimazolam has caused less circulatory depression, which may be advantageous for ES. However, no studies reported the use of remimazolam in perioperative ES management. CASE PRESENTATION: A 45-year-old female patient with ES derived from a ventricular septal defect was scheduled to undergo bilateral adnexectomy for an ovarian tumor. Her oxygen saturation was 80% with 3 L/min oxygen at rest, and her pulmonary and systemic flow ratio was 0.53. She underwent general anesthesia with remimazolam, and intraoperative hemodynamics was stable without hypotension or reduced oxygen saturation. CONCLUSIONS: Our successful management of ovarian tumor surgery in a patient with ES using remimazolam reveals its potential effectiveness in perioperative care.

Association between intraoperative end-tidal carbon dioxide and postoperative organ dysfunction in major abdominal surgery: A cohort study.

BACKGROUND: Data on the effects of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative organ dysfunction are limited. Thus, this study was designed to investigate the relationship between the intraoperative EtCO2 level and postoperative organ dysfunction in patients who underwent major abdominal surgery under general anesthesia. METHODS: We conducted a cohort study involving patients who underwent major abdominal surgery under general anesthesia at Kyoto University Hospital. We classified those with a mean EtCO2 of less than 35 mmHg as low EtCO2. The time effect was determined as the minutes when the EtCO2 value was below 35 mmHg, whereas the cumulative effect was evaluated by measuring the area below the 35-mmHg threshold. The outcome was postoperative organ dysfunction, defined as a composite of at least one organ dysfunction among acute renal injury, circulatory dysfunction, respiratory dysfunction, coagulation dysfunction, and liver dysfunction within 7 days after surgery. RESULTS: Of the 4,171 patients, 1,195 (28%) had low EtCO2, and 1,428 (34%) had postoperative organ dysfunction. An association was found between low EtCO2 and increased postoperative organ dysfunction (adjusted risk ratio, 1.11; 95% confidence interval [CI], 1.03-1.20; p = 0.006). Additionally, long-term exposure to EtCO2 values of less than 35 mmHg (≥224 min) was associated with postoperative organ dysfunction (adjusted risk ratio, 1.18; 95% CI, 1.06-1.32; p = 0.003) and low EtCO2 severity (area under the threshold) (adjusted risk ratio, 1.13; 95% CI, 1.02-1.26; p = 0.018). CONCLUSIONS: Intraoperative low EtCO2 of below 35 mmHg was associated with increased postoperative organ dysfunction.

Agreement between continuous cardiac output measured by the fourth-generation FloTrac/Vigileo system and a pulmonary artery catheter in adult liver transplantation.

In liver transplantation for end-stage liver failure, monitoring of continuous cardiac output (CCO) is used for circulatory management due to hemodynamic instability. CCO is often measured using the minimally invasive FloTrac/Vigileo system (FVS-CCO), instead of a highly invasive pulmonary artery catheter (PAC-CCO). The FVS has improved accuracy due to an updated cardiac output algorithm, but the effect of this change on the accuracy of FVS-CCO in liver transplantation is unclear. In this study, we assessed agreement between fourth-generation FVS-CCO and PAC-CCO in 20 patients aged ≥ 20 years who underwent scheduled or emergency liver transplantation at Kyoto University Hospital from September 2019 to June 2021. Consent was obtained before surgery and data were recorded throughout the surgical period. Pearson correlation coefficient (r), Bland-Altman and 4-quadrant plot analyses were performed on the extracted data. A total of 1517 PAC-CCO vs. FVS-CCO data pairs were obtained. The mean PAC-CCO was 8.73 L/min and the mean systemic vascular resistance was 617.5 dyne·s·cm-5, r was 0.48, bias was 1.62 L/min, the 95% limits of agreement were - 3.04 to 6.27, and the percentage error was 54.36%. These results show that agreement and trending between fourth-generation FVS-CCO and PAC-CCO are low in adult liver transplant recipients.

Relationship between the Use of Fentanyl-Based Intravenous Patient-Controlled Analgesia and Clinically Significant Events in Laparoscopic Gynecological Surgery: A Single-Center Retrospective Cohort Study.

Background: This study examined the relationship between the use of fentanyl-based intravenous patient-controlled analgesia (ivPCA) and the incidence of a clinically significant event (CSE), while considering both the analgesic effects and side effects in laparoscopic gynecological surgery. Methods: This study included 816 patients undergoing laparoscopic gynecological surgery under general anesthesia at Kyoto University Hospital between 2012 and 2018. The primary exposure was the use of fentanyl-based ivPCA. We defined an outcome measure­CSE­that integrates severe wound pain and vomiting assumed to negatively affect patient recovery. We performed multivariable logistic regression analysis to assess the independent relationship between ivPCA use and CSE. Results: Multivariable logistic regression analysis revealed that fentanyl-based ivPCA was independently associated with increased CSE (adjusted odds ratio (95% confidence interval): 1.80 (1.24−2.61), p = 0.002). Use of ivPCA was associated with a reduced incidence of postoperative severe wound pain (adjusted odds ratio (95% confidence interval): 0.50 (0.27−0.90), p = 0.022), but was also associated with an increased incidence of vomiting (adjusted odds ratio (95% confidence interval): 2.65 (1.79−3.92), p < 0.001). Conclusion: The use of fentanyl-based ivPCA in laparoscopic gynecological surgery is associated with increased CSE.

Association between intraoperative end-tidal carbon dioxide and postoperative nausea and vomiting in gynecologic laparoscopic surgery.

Gynecologic laparoscopic surgery has a high incidence of postoperative nausea and vomiting (PONV). Studies suggest that low intraoperative end-tidal carbon dioxide (EtCO2) is associated with an increased incidence of PONV, but the results have not been consistent among studies. This study investigated the association between intraoperative EtCO2 and PONV in patients undergoing gynecologic laparoscopic surgeries under general anesthesia. This retrospective cohort study involved patients who underwent gynecologic laparoscopic surgeries under general anesthesia at Kyoto University Hospital. We defined low EtCO2 as a mean EtCO2 of < 35 mmHg. Multivariable modified Poisson regression analysis examined the association between low EtCO2 and PONV during postoperative two days and the postoperative length of hospital stay (PLOS). Of the 739 patients, 120 (16%) had low EtCO2, and 430 (58%) developed PONV during postoperative two days. There was no substantial association between low EtCO2 and increased incidence of PONV (adjusted risk ratio: 0.96; 95% confidence interval [CI] 0.80-1.14; p = 0.658). Furthermore, there was no substantial association between low EtCO2 and prolonged PLOS (adjusted difference in PLOS: 0.13; 95% CI - 1.00 to 1.28; p = 0.816). Intraoperative low EtCO2, specifically a mean intraoperative EtCO2 below 35 mmHg, was not substantially associated with either increased incidence of PONV or prolonged PLOS.

A Nationwide Questionnaire Survey on Awake Craniotomy in Japan.

The number of awake craniotomies is increasing because of its beneficial features. However, not enough information is available regarding the current status of awake craniotomy in Japan. To evaluate the current status of awake craniotomy in institutes, a nationwide questionnaire survey was conducted. From June to August 2019, we conducted a questionnaire survey on awake craniotomy in the neurosurgery department of 45 institutes that perform awake craniotomies in Japan. Responses were obtained from 39 institutes (response rate, 86.7%). The main methods of awake craniotomy were almost the same in all institutes. Twenty-six institutes (66.7%) had fewer than 10 awake craniotomies (low-volume institutes) per year, and 13 high-volume institutes (33.3%) performed more than 10 awake craniotomies annually. Some institutes experienced a relatively high frequency of adverse events. In 11 institutes (28.2%), the frequency of intraoperative seizures was more than 10%. An intraoperative seizure frequency of 1%-9%, 10%-29%, and over 30% was identified in 12 (92%), 0 (0%), and 1 (8%) of the high-volume institutes, which was significantly less than in 16 (62%), 10 (38%), and 0 (0%) of the low-volume institutes (p = 0.0059). The routine usage of preoperative antiepileptic drugs was not different between them, but the old type was used more often in the low-volume institutes (p = 0.0022). Taken together, the annual number of awake craniotomies was less than 10 in over two-thirds of the institutes. Fewer intraoperative seizures were reported in the high-volume institutes, which tend not to preoperatively use the old type of antiepileptic drugs.

Incidence, clinical characteristics and long-term prognosis of postoperative symptomatic venous thromboembolism: a retrospective cohort study.

OBJECTIVES: The purpose of this study was to evaluate the incidence, clinical characteristics and prognosis of postoperative symptomatic venous thromboembolism (VTE) in Japan. DESIGN: Retrospective observational study. Two data sets, Contemporary ManageMent AND outcomes in patients with Venous ThromboEmbolism (COMMAND VTE) Registry and Japanese Society of Anesthesiologists (JSA) annual report, were used for current analyses. SETTING: Eighteen of 29 centres participated in the COMMAND VTE Registry. PARTICIPANTS: Acute symptomatic patients with VTE who had undergone surgery 2 months prior to the diagnosis at 18 centres from January 2010 to December 2013 were identified in the COMMAND VTE Registry. From each centre's JSA annual report, the overall population that had received anaesthetic management during this period was retrieved. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the incidences and clinical characteristics of postoperative symptomatic VTE. The secondary outcomes were recurrent VTE, major bleeding and all-cause death. RESULTS: We identified 137 patients with postoperative symptomatic VTE, including 57 patients with pulmonary embolism. The incidences of postoperative symptomatic VTE and pulmonary embolism were 0.067% and 0.028%, respectively, based on data from 2 03 943 patients who underwent surgery, managed by anaesthesiologists, during the study period. The incidences of postoperative symptomatic VTE varied widely, depending on surgical and anaesthetic characteristics. Postoperative symptomatic VTE occurred at a median of 8 days after surgery, with 58 patients (42%) diagnosed within 7 days. The cumulative incidence, 30 days after VTE, of recurrent VTE, major bleeding, and all-cause death was 3.0%, 5.2%, and 3.7%, respectively. CONCLUSION: This study, combining the large real-world VTE and anaesthesiology databases in Japan revealed the incidence, clinical features and prognosis of postoperative symptomatic VTE, providing useful insights for all healthcare providers involved in various surgeries. TRIAL REGISTRATION: Not applicable.

Intraoperative end-tidal carbon dioxide and postoperative mortality in major abdominal surgery: a historical cohort study.

PURPOSE: There is a paucity of data on the effect of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative mortality. The purpose of this study was to investigate the relationship between intraoperative EtCO2 and 90-day mortality in patients undergoing major abdominal surgery under general anesthesia. METHODS: We conducted a historical cohort study of patients undergoing major abdominal surgery under general anesthesia at Kyoto University Hospital. We measured the intraoperative EtCO2, and patients with a mean EtCO2 value < 35 mm Hg were classified as low EtCO2. The time effect was determined based on minutes below an EtCO2 of 35 mm Hg, and cumulative effects were evaluated by measuring the area under the threshold of 35 mm Hg for each patient. RESULTS: Of 4,710 patients, 1,374 (29%) had low EtCO2 and 55 (1.2%) died within 90 days of surgery. Multivariable Cox regression analysis-adjusted for age, American Society of Anesthesiologists Physical Status classification, sex, laparoscopic surgery, emergency surgery, blood loss, mean arterial pressure, duration of surgery, type of surgery, and chronic obstructive pulmonary disease-revealed an association between low EtCO2 and 90-day mortality (adjusted hazard ratio, 2.2; 95% confidence interval [CI], 1.2 to 3.8; P = 0.006). In addition, severity of low EtCO2 was associated with an increased 90-day mortality (area under the threshold; adjusted hazard ratio; 2.9, 95% CI, 1.2 to 7.4; P =0.02); for long-term exposure to an EtCO2 < 35 mm Hg (≥ 226 min), the adjusted hazard ratio for increased 90-day mortality was 2.3 (95% CI, 0.9 to 6.0; P = 0.08). CONCLUSION: A mean intraoperative EtCO2 < 35 mm Hg was associated with increased postoperative 90-day mortality.

RéSUMé: OBJECTIF: Il n'existe que très peu de données s'intéressant à l'effet du niveau peropératoire télé-expiratoire du dioxyde de carbone (EtCO2) sur la mortalité postopératoire. L'objectif de cette étude était d'examiner la relation entre l'EtCO2 peropératoire et la mortalité à 90 jours chez des patients subissant une chirurgie abdominale majeure sous anesthésie générale. MéTHODE: Nous avons réalisé une étude de cohorte historique portant sur des patients subissant une chirurgie abdominale majeure sous anesthésie générale à l'Hôpital universitaire de Kyoto. Nous avons mesuré l'EtCO2 peropératoire, et les patients avec une valeur moyenne d'EtCO2 < 35 mmHg ont été catégorisés comme EtCO2 faible. L'effet temps a été déterminé en fonction de la durée, en minutes, avec une EtCO2 inférieure à 35 mmHg, et les effets cumulatifs ont été évalués en mesurant l'aire sous le seuil de 35 mmHg pour chaque patient. RéSULTATS: Sur 4710 patients, 1374 (29 %) avaient une EtCO2 faible et 55 (1,2 %) sont décédés dans les 90 jours suivant la chirurgie. Une analyse de régression multivariée de Cox, ajustée pour tenir compte des facteurs suivants : âge, statut physique selon l'American Society of Anesthesiologists, sexe, chirurgie par laparoscopie, chirurgie d'urgence, pertes de sang, tension artérielle moyenne, durée de la chirurgie, type de chirurgie et maladie pulmonaire obstructive chronique, a révélé une association entre une EtCO2 faible et la mortalité à 90 jours (rapport de risque ajusté, 2,2; intervalle de confiance [IC] à 95 %, 1,2 à 3,8; P = 0,006). De plus, la sévérité de l'EtCO2 basse était associée à une augmentation de la mortalité à 90 jours (aire sous le seuil; rapport de risque ajusté; 2,9, IC 95 %, 1,2 à 7,4; P =0,02); pour une exposition à long terme à une EtCO2 < 35 mmHg (≥ 226 minutes), le rapport de risque ajusté pour une mortalité accrue à 90 jours était de 2,3 (IC 95 %, 0,9 à 6,0 ; P = 0,08). CONCLUSION: Une EtCO2 peropératoire moyenne < 35 mmHg était associée à une augmentation de la mortalité postopératoire à 90 jours.

Factors associated with somnolence during brain function mapping in awake craniotomy.

Somnolence during brain function mapping is one of the factors that inhibit the accomplishment of the goals of awake craniotomy. We examined the effect of anesthesia depth measured by bispectral index (BIS) during pre-awake phase on somnolence during brain function mapping and also explored the factors associated with somnolence. We examined the association between BIS values during pre-awake phase and somnolence during the first 30 min of brain function mapping in 55 patients who underwent awake craniotomy at Kyoto University Hospital from 2015 to 2018. The pre-awake BIS value was defined as the mean BIS value for 60 min before the removal of the airway. Somnolence during brain function mapping was the primary outcome, defined as either of the following conditions: inability to follow up, disorientation, or inability to assess speech function. Additionally, we compared patient or perioperative variables between patients with/without somnolence. Somnolence occurred in 14 patients (25.5%), of which 6 patients (10.9%) were unable to complete brain function mapping. There was no significant difference in the pre-awake BIS value between patients with/without somnolence (median: 46 vs. 49, P = 0.192). Somnolence was not significantly associated with age, gender, and the number of preoperative anticonvulsive drugs, but patients with somnolence had a significantly lower preoperative Western Aphasia Battery (WAB) aphasia quotient score (median 93.8 vs. 98.6, P = 0.011). We did not find an association between pre-awake BIS value and somnolence during brain function mapping. Somnolence likely occurs in patients with a low preoperative WAB aphasia quotient score.

Knot formation in a thoracic epidural catheter: a case report.

BACKGROUND: Although most epidural catheter knot formation has been reported in lumbar epidural catheter placement, knot formation in a thoracic epidural catheter has been experienced. CASE PRESENTATION: A 72-year-old woman was scheduled for laparoscopic cholecystectomy under general anesthesia combined with epidural anesthesia. The epidural catheter was inserted through the Th10-Th11 intervertebral space and was placed 7 cm into the epidural space. Two days after the surgery, the anesthesiologist was called because of difficulty in removing the epidural catheter. The catheter was eventually removed when the anesthesiologist carefully pulled it while strongly bending the patient's body to the right, although resistance was still noted. The removed catheter was observed to have a hard single knot formed at about 3 mm from the tip. CONCLUSIONS: A knot formation of an epidural catheter placed at the thoracic level was experienced. Limiting the length of catheter placement may prevent knot formation.

The association between arterial pulse waveform analysis device and in-hospital mortality in high-risk non-cardiac surgeries.

BACKGROUND: Perioperative goal-directed fluid therapy is used for haemodynamic optimization in high-risk surgeries. Cardiac output monitoring can be performed by a specialized pressure transducer for arterial pulse waveform analysis (S-APWA). No study has assessed whether real-world use of S-APWA is associated with post-operative outcomes; therefore, using a Japanese administrative claims database, we retrospectively investigated whether S-APWA use is associated with in-hospital mortality among patients undergoing high-risk surgery under general anaesthesia. METHODS: Adult patients who underwent high-risk surgery under general anaesthesia and arterial catheterization between 2014 and 2016 were divided into S-APWA and conventional arterial pressure transducer groups, then compared regarding baseline factors and outcomes. Logistic regression analysis was performed to compare in-hospital mortality. Subgroup analyses evaluated S-APWA efficacy and outcomes based on the type of surgery and patients' comorbidity. RESULTS: S-APWA was used in 6859 of 23 655 (29.0%) patients; the crude in-hospital mortality rate was 3.5%. Adjusted analysis showed no significant association between S-APWA use and in-hospital mortality rate (adjusted odds ratio [aOR] = 0.91; 95% confidence interval [CI]: 0.76-1.07; P = .25). S-APWA use was associated with significantly lower in-hospital mortality in patients undergoing vascular surgery (aOR = 0.67; 95% CI: 0.49-0.94), and significantly higher in-hospital mortality in patients undergoing lower limb amputation (aOR = 2.63; 95% CI: 1.32-5.22). S-APWA use and in-hospital mortality were not significantly associated with other subgroups. CONCLUSION: S-APWA use was not associated with in-hospital mortality in the entire study population. However, S-APWA was associated with decreased in-hospital mortality among vascular surgery and increased in-hospital mortality among lower limb amputation.

Derivation and validation of an equation to determine the optimal ventilator setting in children undergoing intracranial revascularization surgery: A single-center retrospective study.

BACKGROUND: It can be difficult to determine the appropriate ventilator settings to maintain normocapnia in children undergoing general anesthesia for surgery for moyamoya disease, especially immediately following anesthesia induction. AIM: We conducted this study to attempt to derive an equation to predict the appropriate ventilator settings and subsequently validated the accuracy of the equation. METHODS: A retrospective study of 91 pediatric patients less than 18 years of age who underwent cerebral revascularization for moyamoya disease at our institution. Fifty-eight patients were used to derive the equation, and the subsequent 33 patients were used to validate the equation. We calculated the required respiratory rate to attain normocapnia based on the median of all values of the minute volume during normocapnia (estimated partial pressure of arterial carbon dioxide of 38-42 mm Hg) and the assumption that the tidal volume was 8 mL/kg body weight. We derived the regression equation from the derivation data set where the required respiratory rate to attain normocapnia was represented by age. We simplified the equation by rounding coefficients to the nearest integer. The level of agreement between the respiratory rate predicted from the equation and the actual required respiratory rate was assessed in the validation group using Bland-Altman analysis. RESULTS: The derived equation is tidal volume = 8 mL/kg body weight, respiratory rate = 24-age/min. Bland-Altman analysis in the validation group revealed that the mean bias between the predicted and actual respiratory rate was 0.29 (standard deviation, 3.67). The percentage of cases where the predicted rate was within ± 10% and ± 20% of the actual rate was 42.4% and 66.7%, respectively. CONCLUSIONS: We derived and validated a simple and easily applicable equation to predict the ventilator settings required to attain normocapnia during general anesthesia in children with moyamoya disease.

Invasive Respiratory or Vasopressor Support and/or Death as a Proposed Composite Outcome Measure for Perioperative Care Research.

BACKGROUND: There is a need for a clinically relevant and feasible outcome measure to facilitate clinical studies in perioperative care medicine. This large-scale retrospective cohort study proposed a novel composite outcome measure comprising invasive respiratory or vasopressor support (IRVS) and death. We described the prevalence of IRVS in patients undergoing major abdominal surgery and assessed the validity of combining IRVS and death to form a composite outcome measure. METHODS: We retrospectively collected perioperative data for 2776 patients undergoing major abdominal surgery (liver, colorectal, gastric, pancreatic, or esophageal resection) at Kyoto University Hospital. We defined IRVS as requirement for mechanical ventilation for ≥24 hours postoperatively, postoperative reintubation, or postoperative vasopressor administration. We evaluated the prevalence of IRVS within 30 postoperative days and examined the association between IRVS and subsequent clinical outcomes. The primary outcome of interest was long-term survival. Multivariable Cox proportional regression analysis was performed to adjust for the baseline patient and operative characteristics. The secondary outcomes were length of hospital stay and hospital mortality. RESULTS: In total, 85 patients (3.1%) received IRVS within 30 postoperative days, 15 of whom died by day 30. Patients with IRVS had a lower long-term survival rate (1- and 3-year survival probabilities, 66.1% and 48.5% vs 95.2% and 84.0%, respectively; P < .001, log-rank test) compared to those without IRVS. IRVS was significantly associated with lower long-term survival after adjustment for the baseline patient and operative characteristics (adjusted hazard ratio, 2.72; 95% confidence interval, 1.97-3.77; P < .001). IRVS was associated with a longer hospital stay (median [interquartile range], 65 [39-326] vs 15 [12-24] days; adjusted P < .001) and a higher hospital mortality (24.7% vs 0.5%; adjusted P < .001). Moreover, IRVS was adversely associated with subsequent clinical outcomes including lower long-term survival (adjusted hazard ratio, 1.78; 95% confidence interval, 1.21-2.63; P = .004) when the analyses were restricted to 30-day survivors. CONCLUSIONS: Patients with IRVS can experience ongoing risk of serious morbidity and less long-term survival even if alive at postoperative day 30. Our findings support the validity of using IRVS and/or death as a composite outcome measure for clinical studies in perioperative care medicine.

Near-infrared spectroscopy underestimates cerebral oxygenation in hemodialysis patients.

Regional cerebral oxygen saturation (rSO2) measured using near-infrared spectroscopy has been reported to be significantly lower in hemodialysis (HD) patients than in non-HD ones, but the mechanisms are unknown. The aim of this prospective study was to assess the accuracy of near-infrared spectroscopy to estimate cerebral oxygenation in HD patients undergoing cardiovascular surgery. Our hypothesis was that rSO2 values would underestimate cerebral oxygenation in HD patients. This study included 113 patients (7 HD patients and 106 non-HD ones) undergoing cardiac or major aortic surgery between December 2015 and November 2017. We evaluated the validity of rSO2 by comparing it with ipsilateral jugular venous oxygen saturation (SjvO2). In HD and non-HD patients, rSO2 and SjvO2 showed a weak correlation (R2: 0.46 and 0.28 in HD and non-HD patients, respectively). Bland-Altman analysis revealed that bias (95% limits of agreement) of rSO2 compared to SjvO2 was - 19.2% ( - 41.7-3.3%) in HD patients and - 1.9% (- 19.3-15.5%) in non-HD ones. The large negative bias suggests that the rSO2 values measured using near-infrared spectroscopy substantially underestimate cerebral oxygenation in HD patients.

Utilization of arterial pulse waveform analysis during non-cardiac surgery in Japan: a retrospective observational study using a nationwide claims database.

Arterial pulse waveform analysis (APWA) is used for cardiac output monitoring. However, data on the frequency of and patient characteristics for specialized pressure transducer for APWA (S-APWA) use are lacking. We retrospectively identified 175,201 patients aged 18 years or older, who underwent non-cardiac surgery under general anesthesia with an arterial catheter from January 1, 2014, to December 31, 2016. We extracted data on patient demographics, comorbidities, surgical and anesthesia characteristics, and hospital characteristics. Among the full study cohort, 24,605 (14.0%) patients were monitored using S-APWA. Further, the use of S-APWA was higher in patients undergoing high-risk surgery than in those undergoing low-risk surgery [high vs low: adjusted odds ratio (aOR) 1.95; 95% confidence interval (CI) 1.76-2.15, moderate vs low: aOR 1.11; 95% CI 1.01-1.22] and those with more comorbidities than in those with less comorbidities (high vs low: aOR 1.49; 95% CI 1.42-1.56, moderate vs low: aOR 1.25; 95% CI 1.20-1.31). S-APWA use was significantly associated with both surgery risk and patients' comorbidities. In conclusion, our study may provide a benchmark for future studies related to the appropriate use of S-APWA.

Transient acute kidney injury after major abdominal surgery increases chronic kidney disease risk and 1-year mortality.

PURPOSE: We conducted a retrospective cohort study to determine incidences of transient and persistent acute kidney injury (AKI) after major abdominal surgery and their impacts on long-term outcome. MATERIALS AND METHODS: We enrolled 3751 patients undergoing major abdominal surgery. Postoperative AKI was classified as transient or persistent based on the return of serum creatinine to the non-AKI range within 7 days post-surgery. Primary outcome was mortality within 1 year. We used multivariable Cox proportional hazard regression analysis to assess independent associations between AKI type and mortality. RESULTS: Most patients with AKI were classified as transient (84%). Compared to patients without AKI, both patients with transient and persistent AKI demonstrated elevated 1-year mortality rates [adjusted hazard ratio (95% confidence interval): 2.01 (1.34-2.93); P = 0.001, and 6.20 (3.00-11.43); P < 0.001, respectively] and greater risk of chronic kidney disease progression at 1 year [adjusted odds ratio (95% confidence interval): 3.87 (2.12-7.08) and 23.70 (9.64-58.22), respectively; both P < 0.001]. CONCLUSIONS: Although most AKI cases after major abdominal surgery recover completely within 7 days, even these patients with transient AKI are at higher risk for 1-year mortality and chronic kidney disease progression compared to patients without AKI.

Acute kidney injury after pediatric liver transplantation: incidence, risk factors, and association with outcome.

PURPOSE: Data on the incidence of, risk factors for, and association with outcomes of acute kidney injury (AKI) after pediatric liver transplantation are scarce. We conducted a retrospective cohort study to determine the incidence of AKI after pediatric liver transplantation. In addition, we examined risk factors for AKI and association of AKI with outcomes. METHODS: This study included 156 children aged between 3 months and 18 years undergoing liver transplantation at Kyoto University Hospital. AKI was defined according to the Kidney Disease: Improving Global Outcomes guidelines based on serum creatinine and urine output. We used multivariable logistic regression with stepwise variable selection to identify independent risk factors for AKI. RESULTS: AKI occurred in 72 patients (46.2%); 34 (21.8%) had stage 1, 32 (20.5%) had stage 2, and 6 (3.8%) had stage 3 AKI. Factors independently associated with the development of AKI were increased preoperative total bilirubin level (adjusted odds ratio, 1.04 per 1 mg/dl; 95% confidence interval, 1.01-1.09; P = 0.026) and increased intraoperative blood loss (adjusted odds ratio, 1.03 per 10 ml/kg; 95% confidence interval, 1.00-1.06; P = 0.022). AKI was significantly associated with prolonged hospitalization (median, 61 vs. 46 days; P = 0.028). In-hospital mortality rate was 4.2% in patients with AKI and 3.6% in those without AKI (P = 1.000). CONCLUSION: The incidence of AKI after pediatric liver transplantation was 46.2%. Increased preoperative total bilirubin level and increased intraoperative blood loss were independently associated with the development of AKI. AKI was associated with prolonged hospitalization.

Relationship Between Intraoperative Hypotension and Acute Kidney Injury After Living Donor Liver Transplantation: A Retrospective Analysis.

OBJECTIVE: Acute kidney injury (AKI) is common after liver transplantation (LT) and has a significant impact on outcomes. Although several risk factors for post-LT AKI have been identified, the effect of intraoperative hemodynamic status on post-LT AKI remains unknown. Therefore, the authors aimed to investigate the relationship between hemodynamic parameters during LT and postoperative AKI. DESIGN: A retrospective observational study. SETTING: University hospital. PARTICIPANTS: Patients who underwent living donor LT (n = 231). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Severe AKI (stages 2-3 according to recent guidelines) was the primary outcome. Multivariable logistic regression analysis was used to control for confounding variables to obtain the independent relationship between intraoperative hemodynamic parameters (mean arterial pressure [MAP] and cardiac index) and severe AKI. The prevalence of severe AKI was 30.7%. Nadir MAP during the surgery was independently predictive of severe AKI (adjusted odds ratio, 2.11 [95% confidence interval, 1.32-3.47] per 10-mmHg decrease; p = 0.002). Subgroup analyses based on various patient or operative variables and extensive sensitivity analyses showed substantially similar results. Severe hypotension (MAP<40 mmHg), even for fewer than 10 minutes, was related significantly to severe AKI (adjusted odds ratio, 3.80 [95% confidence interval, 1.17-12.30]; p = 0.026). In contrast, nadir cardiac index was not related significantly to severe AKI. CONCLUSIONS: The authors found an independent relationship between degree of intraoperative hypotension and risk of severe AKI in living donor LT recipients. Severe hypotension, even for a short duration, was related significantly to severe AKI.