Thermosensitive TRPV4 channels mediate temperature-dependent microglia movement.

Microglia maintain central nervous system homeostasis by monitoring changes in their environment (resting state) and by taking protective actions to equilibrate such changes (activated state). These surveillance and protective roles both require constant movement of microglia. Interestingly, induced hypothermia can reduce microglia migration caused by ischemia, suggesting that microglia movement can be modulated by temperature. Although several ion channels and transporters are known to support microglia movement, the precise molecular mechanism that regulates temperature-dependent movement of microglia remains unclear. Some members of the transient receptor potential (TRP) channel superfamily exhibit thermosensitivity and thus are strong candidates for mediation of this phenomenon. Here, we demonstrate that mouse microglia exhibit temperature-dependent movement in vitro and in vivo that is mediated by TRPV4 channels within the physiological range of body temperature. Our findings may provide a basis for future research into the potential clinical application of temperature regulation to preserve cell function via manipulation of ion channel activity.

Modified del Nido cardioplegia is associated with low incidence of low main strong ion difference and hyperchloremia in pediatric patients after cardiac surgery.

PURPOSE: The aims of this study were (1) to determine the associations of cardioplegic solutions with postoperative main strong ion difference (mSID), which is the difference between sodium ion concentration and chloride ion concentration ([Cl-]) and (2) to determine the associations of cardioplegic solutions with markers of organ dysfunction. METHODS: In this retrospective cohort study, patients aged <5 years who underwent cardiac surgery in a tertiary teaching hospital were included. Patients were classified on the basis of the type of cardioplegic solution: modified del Nido cardioplegia (mDNC) and conventional cardioplegia (CC). The effects of mDNC on postoperative mSID and markers of organ functions were examined using propensity-matched analysis. RESULTS: A total of 500 cases were included. mDNC solution was used in 163 patients (32.6%). After propensity score matching, patients in the mDNC group (n = 152) had significantly higher minimum mSID [28 (26, 30) mEq/L vs. 27 (25, 29) mEq/L, p = 0.02] and lower maximum [Cl-] [112 (109, 114) mEq/L vs. 113 (111, 117) mEq/L, p < 0.001] than patients in the CC group (n = 304). The incidences of low mSID and hyperchloremia in the mDNC group were significantly lower than those in the CC group (63.8 vs. 75.7%, p = 0.01 and 63.2 vs. 79.3%, p < 0.001, respectively). There was no significant difference in the incidence of postoperative acute kidney injury and B-type natriuretic peptide level between the two groups. CONCLUSION: The use of modified del Nido cardioplegia may reduce the incidence of abnormal mSID and hyperchloremia compared with the use of a chloride-rich cardioplegic solution.

Outcomes associated with unrecognized acute kidney injury in postoperative pediatric cardiac patients.

BACKGROUND: The present retrospective study was carried out to determine the incidence of unrecognized cardiac surgery-associated acute kidney injury (CSA-AKI) due to infrequency of serum creatinine (SCr) measurements in pediatric cardiac patients and to assess the association between unrecognized CSA-AKI and clinical outcomes. METHODS: This study was a single-center, retrospective study of pediatric patients who underwent cardiac surgery. Patients were diagnosed with CSA-AKI based on SCr measurements, and unrecognized CSA-AKI was defined under the assumptions that there had been only one or two SCr measurements within 48 h after surgery: CSA-AKI unrecognized by one SCr measurement (AKI-URone), CSA-AKI unrecognized by two SCr measurements (AKI-URtwo), and CSA-AKI recognized by one and two SCr measurements (AKI-R). The change of SCr from baseline to postoperative day 30 (delta SCr30d) was assessed as a surrogate of kidney recovery. RESULTS: In a total of 557 cases, 313 patients (56.2%) were diagnosed with CSA-AKI, 188 (33.8%) of whom had unrecognized CSA-AKI. Delta SCr30d in the AKI-URtwo group and delta SCr30d in the AKI-URone group was not significantly different from delta SCr30d in the non-AKI group (p = 0.67 and p = 0.79, respectively). There were significant differences in the durations of mechanical ventilation, serum B-type natriuretic peptide levels, and lengths of stay in hospital between the non-AKI group and the AKI-URtwo group and between the non-AKI group and the AKI-URtwo group. CONCLUSIONS: Unrecognized CSA-AKI due to infrequent SCr measurements is not rare and is associated with prolonged mechanical ventilation, high postoperative BNP level, and prolonged length of stay in hospital. A higher resolution version of the Graphical abstract is available as Supplementary information.

Associations of systemic oxygen consumption with age and body temperature under general anesthesia: retrospective cohort study.

BACKGROUND: Body temperature (BT) is thought to have associations with oxygen consumption (VO2). However, there have been few studies in which the association between systemic VO2 and BT in humans was investigated in a wide range of BTs. The aims of this study were 1) to determine the association between VO2 and age and 2) to determine the association between VO2 and BT. METHODS: This study was a retrospective study of patients who underwent surgery under general anesthesia at a tertiary teaching hospital. VO2 was measured by the Dräger Perseus A500 anesthesia workstation (Dräger Medical, Lubeck, Germany). The associations of VO2 with age and BT were examined using spline regression and multivariable regression analysis with a random effect. RESULTS: A total of 7,567 cases were included in this study. A linear spline with one knot shows that VO2 was reduced by 2.1 ml/kg/min with one year of age (p < 0.001) among patients less than 18 years of age and that there was no significant change in VO2 among patients 18 years of age or older (estimate: 0.014 ml/kg/min, p = 0.08). VO2 in all bands of BT < 36.0 °C was not significantly different from VO2 in BT > = 36 °C and < 36.5 °C. Multivariable linear regression analysis showed that compared with VO2 in BT > = 36 °C and < 36.5 °C as a reference, VO2 levels were significantly higher by 0.57 ml/kg/min in BT > = 36.5 °C and < 37 °C (p < 0.001), by 1.8 ml/kg/min in BT > = 37 °C and < 37.5 °C (p < 0.001), by 3.6 ml/kg/min in BT > = 37.5 °C and < 38 °C (p < 0.001), by 4.9 ml/kg/min in BT > = 38 °C and < 38.5 °C (p < 0.001), and by 5.7 ml/kg/min in BT > = 38.5 °C (p < 0.001). The associations between VO2 and BT were significantly different among categorized age groups (p = 0.03). CONCLUSIONS: VO2 increases in parallel with increase in body temperature in a hyperthermic state but remains constant in a hypothermic state. Neonates and infants, who have high VO2, may have a large systemic organ response in VO2 to change in BT.

An Assessment of the Practice of Neuromuscular Blockade and the Association Between Its Prophylactic Use and Outcomes Among Postoperative Pediatric Cardiac Patients.

OBJECTIVES: The authors investigated the management of neuromuscular blocking agents (NMBAs) for pediatric patients after cardiac surgery, and compared the outcomes of patients who received prophylactic NMBA (pNMBA) infusions and patients without pNMBA infusions. DESIGN: A retrospective cohort study. SETTING: At a tertiary teaching hospital. PARTICIPANTS: Patients younger than 18, with congenital heart disease, who underwent cardiac surgery. INTERVENTIONS: Commencement of NMBA infusion in the first 2 hours after surgery MEASUREMENTS AND MAIN RESULTS: The primary endpoint was a composite of one or more of the following major adverse events (MAEs) that occurred within 7 days after surgery: death from any cause, a circulatory collapse that needed cardiopulmonary resuscitation, and requirement for extracorporeal membrane oxygenation. The secondary endpoints included the total duration of mechanical ventilation for the first 30 days after surgery. A total of 566 patients were included in this study. The MAEs occurred in 13 patients (2.3%). An NMBA was commenced within 2 hours after surgery in 207 patients (36.6%). There were significant differences in the incidence of postoperative MAEs between the pNMBA group and the non-pNMBA group (5.3% v 0.6%; p < 0.001). In multivariate regression models, pNMBA infusion was not significantly associated with the incidence of MAEs (odds ratio: 1.79, 95% CI: 0.23-13.93, p = 0.58), but was significantly associated with prolonged mechanical ventilation by 3.85 days (p < 0.001). CONCLUSIONS: Postoperative prophylactic neuromuscular blockade after cardiac surgery can be associated with prolonged mechanical ventilation, but has no association with MAEs among pediatric patients with congenital heart disease.

Early Fluid Balance Is Associated with 90-Day Mortality in Patients Receiving Continuous Renal Replacement Therapy.

Continuous renal replacement therapy (CRRT) is widely used to control fluid balance, but the optimal fluid balance to improve the prognosis of patients remains debated. Appropriate fluid management may depend on hemodynamic status. We investigated the association between 90-day mortality and fluid balance/mean arterial pressure (MAP) in patients receiving CRRT. This single-center retrospective study was conducted between May 2018 and March 2021. Based on the cumulative fluid balance at 72 h after initiation of CRRT, the cases were divided into negative (< 0 mL) and positive (> 0 mL) fluid balance groups. Ninety-day mortality was higher in the positive fluid balance group (p=0.009). At 4 h before and after CRRT initiation, the mean MAP was lower in the positive fluid balance group (p<0.05). After multivariate cox adjustment, 72-h positive fluid balance was independently associated with 90-day mortality (p=0.004). In addition, the cumulative fluid balance was associated with 90-day mortality (p<0.05) in cases without shock, high APACHE II score, sepsis, dialysis dependence, or vasopressor use. A 72-h positive fluid balance was associated with 90-day mortality in patients receiving CRRT.

Prolonged Double-Low Time and the Incidence of Postoperative Delirium in Surgical ICU Patients.

An intraoperative double-low condition is defined as concurrent low values for bispectral index (BIS) and mean arterial pressure (MAP), and may predict perioperative outcomes. We hypothesized that prolonged double-low times might be associated with an increased incidence of postoperative delirium. We conducted a single-center retrospective observational study on patients who had been admitted to our hospital's intensive care unit (ICU) after surgery and whose BIS and MAP data had been recorded during general anesthesia. The primary outcome was the incidence of postoperative delirium. A double-low condition was defined as BIS < 45 and MAP <75 mmHg. The total double-low time was calculated in 1-min increments and used to divide the patients into quintiles. Multiple logistic regression analyses were conducted. Among the 334 patients included in the study, the incidence of postoperative delirium was 15.6% (n=52). Multiple logistic regression analysis revealed that a prolonged double-low time, defined as a total double-low time of > 42 min (i.e., third, fourth, and fifth quintiles), was significantly associated with an increased incidence of postoperative delirium (adjusted odds ratio: 2.61, 95% confidence interval: 1.27-5.37, p=0.009). Prolonged double-low time during general anesthesia was independently associated with an increased incidence of postoperative delirium in surgical ICU patients.

Relationship of Intraoperative SpO2 and ETCO2 Values with Postoperative Hypoxemia in Elderly Patients after Non-Cardiac Surgery.

Elderly patients are at higher risk of postoperative hypoxemia due to their decreased respiratory function. The aim of this study was to investigate the relationship of intraoperative oxygen saturation (SpO2) and end-expiratory carbon dioxide (ETCO2) values with postoperative hypoxemia in elderly patients. The inclusion criteria were: 1) patients aged≥75 years; 2) underwent general anesthesia in non-cardiac surgery; 3) operative time longer than two hours; and 4) admission to the intensive care unit (ICU) following surgery performed between January and December 2019. Intraoperative SpO2 and ETCO2 values were collected every minute for the first two hours during surgery. The 253 patients were divided into two groups: SpO2≥92% and SpO2<92%. The time-weighted averages of intraoperative SpO2 and ETCO2 were used to compare differences between the two groups. The incidence of postoperative hypoxemia was 22.5%. For similar ventilator settings, patients with postoperative hypoxemia had lower intraoperative SpO2 and higher ETCO2 values. Sex, ASA classification, and intraoperative SpO2 were independent risk factors for postoperative hypoxemia. In conclusion, postoperative SpO2<92% was a frequent occurrence (> 20%) in elderly patients who underwent major non-cardiac surgery. Postoperative hypoxemia was associated with low intraoperative SpO2 and relatively higher ETCO2.

Regional Cerebral Oxygen Saturation and Estimated Oxygen Extraction Ratio as Predictive Markers of Major Adverse Events in Infants with Congenital Heart Disease.

Regional cerebral oxygen saturation (ScO2) determined by near-infrared spectroscopy, monitoring both arterial and venous blood oxygenation of the brain, could reflect the balance between oxygen delivery and consumption. The aim of this study was to determine the predictabilities of ScO2 and estimated oxygen extraction ratio (eO2ER) with outcomes in infants with congenital heart disease (CHD). This study was a two-center, retrospective study of patients at 12 months of age or younger with CHD who underwent cardiac surgery. The primary outcome was a composite of one or more major adverse events (MAEs) after surgery: death from any cause, circulatory collapse that needed cardiopulmonary resuscitation, and requirement for extracorporeal membrane oxygenation. Based on the assumptions of arterial to venous blood ratio, eO2ER was calculated. A total of 647 cases were included in this study. MAEs occurred in 16 patients (2.5%). There were significant differences in post-bypass ScO2 [46.61 (40.90, 52.05) vs. 58.52 (51.52, 66.08), p < 0.001] and post-bypass eO2ER [0.66 (0.60, 0.78) vs. 0.52 (0.43, 0.61), p < 0.001] between patients with MAEs and patients without MAEs. Area under the receiver operating curve (AUROC) of post-bypass ScO2 was 0.818 (95% confidence interval: 0.747-0.889), AUROC of post-bypass eO2ER was 0.783 (0.697-0.870) and AUROC of post-bypass maximum serum lactate level was 0.635 (0.525-0.746). Both ScO2 and eO2ER, especially after weaning off bypass, are acceptable predictive markers for predicting MAEs after cardiac surgery in infants.(227 words).

Reviewing COVID-19 from an anesthesiologist's perspective in 2022: JA symposium.

The COVID-19 pandemic is ongoing as of September 2022. Since January 2020 when the first case was reported in Japan, the medical community faced a variety of problems both domestically and internationally. It is meaningful to review the impact of COVID-19 from an anesthesiologist's perspective to clarify our policy for future infectious disease outbreaks. In this year's Journal of Anesthesia (JA) symposium, five experts who were deeply involved in the COVID-19 response reviewed the past 2.5 years and made recommendations for potential future pandemics. Anesthesiologists are specialists in airway management and their role in intubating patients with COVID-19 has received much attention. However, they have also played an important backup role in intensive care as critical care physicians and must be more involved in critical care in regular (non-pandemic) times to properly fulfill this role. It is especially important for the Japan Society of Anesthesiologists and JA to quickly disseminate accurate information on unknown infectious diseases to the medical community and wider society. Therefore, it is important to promptly publish papers that are quality-assured through peer review.

Stroke volume variation and dynamic arterial elastance predict fluid responsiveness even in thoracoscopic esophagectomy: a prospective observational study.

PURPOSE: It remains unknown whether stroke volume variation (SVV), pulse pressure variation (PPV), and dynamic arterial elastance (Eadyn) are suitable for monitoring fluid management during thoracoscopic esophagectomy (TE) in the prone position with one-lung ventilation and artificial pneumothorax. Our study aimed to evaluate the accuracy of SVV, PVV, and Eadyn in predicting the fluid responsiveness in these patients. METHODS: We recruited 24 patients who had undergone TE. Patients with a mean arterial blood pressure ≤ 65 mmHg received a 200-ml bolus of 6% hydroxyethyl starch over 10 min. Fluid responders showed the stroke volume index ≥ 15% 5 min after the fluid bolus. Receiver operating characteristic (ROC) curves were generated and area under the ROC curve (AUROC) was calculated. RESULTS: We obtained 61 fluid bolus data points, of which 20 were responders and 41 were non-responders. The median SVV before the fluid bolus in responders was significantly higher than that in non-responders (18% [interquartile range (IQR) 13-21] vs. 12% [IQR 8-15], P = 0.001). Eadyn was significantly lower in responders than in non-responders (0.55 [IQR 0.45-0.78] vs. 0.91 [IQR 0.67-1.00], P < 0.001). There was no difference in the PPV between the groups. The AUROC was 0.76 for SVV (95% confidence interval [CI] 0.62-0.89, P = 0.001), 0.56 for PPV (95% CI 0.41-0.71, P = 0.44), and 0.82 for Eadyn (95% CI 0.69-0.95, P < 0.001). CONCLUSIONS: SVV and Eadyn are reliable parameters for predicting fluid responsiveness in patients undergoing TE.

Efficacy of prophylactic high-flow nasal cannula therapy for postoperative pulmonary complications after pediatric cardiac surgery: a prospective single-arm study.

PURPOSE: This study investigated the incidence of postoperative pulmonary complications (PPC) when high-flow nasal cannula therapy (HFNC) is used prophylactically after pediatric cardiac surgery, and evaluated its efficacy. METHODS: This was a single-arm prospective interventional study that was conducted in a tertiary teaching hospital with eight beds in the pediatric cardiac ICU after approval by the Ethics Committee. One-hundred children under the age of 48 months who were scheduled for cardiac surgery for congenital heart disease were recruited. HFNC was used for 24 h after extubation at a 2 L/kg/min flow rate. The primary outcome was the incidence of PPC within 48 h after extubation. PPC was defined as atelectasis and acute respiratory failure meeting certain criteria. We considered prophylactic HFNC as effective if the prevalence of PPC was < 10%, based on previous reports of reintubation rates of 6%-9% after pediatric cardiac surgery. RESULTS: A total of 91 patients were finally included in the analysis. The incidence of PPC within 48 h after extubation was 18.7%, whereas atelectasis was observed in 13.2%, and acute respiratory failure in 8.8%. Reintubation rate within 48 h after extubation was 0%. CONCLUSIONS: We found the incidence of PPC with prophylactic HFNC after planned extubation after pediatric cardiac surgery. However, the incidence was > 10%; therefore, we could not demonstrate its efficacy in this single-arm study. Further studies are needed to investigate whether the HFNC could be adapted as first-line oxygen therapy after pediatric cardiac surgery.

The Effect of Postinduction Blood Glucose on Intraoperative Hypothermia.

Background and Objectives: Hypothermia frequently occurs in patients undergoing surgery and is associated with adverse complications. Therefore, this study aimed to investigate the postinduction blood glucose and occurrence of intraoperative hypothermia in patients undergoing laparoscopic surgery. Materials and Methods: This retrospective observational study included 334 patients aged ≥20 years who had undergone elective laparoscopic surgery. The primary outcome of this study was the incidence of intraoperative hypothermia. Stratified analysis revealed differences between patients with and without diabetes. Results: Hypothermia occurred in 200 (59.9%) patients. In multivariate analysis, out-of-range postinduction glucose was independently associated with hypothermia (>150 mg/dL: odds ratio 2.17, 95% confidence interval (1.02, 4.61), p = 0.045; <110 mg/dL: odds ratio 2.02, 95% confidence interval (1.15, 3.55), p = 0.015), whereas preoperative HbA1c >6% was not significantly associated with hypothermia (odds ratio 1.02, 95% confidence interval (0.56, 1.84), p = 0.961). Considering only patients with diabetes, the incidence of hypothermia was lower (p = 0.002), the duration of hypothermia was shorter (p = 0.007), and the minimum temperature was higher (p = 0.006) in those with a postinduction glucose level of 110-150 mg/dL. Conclusions: The postinduction glucose level is independently associated with intraoperative hypothermia. Out-of-range postinduction glucose appeared to have an impact on the development of hypothermia in patients with diabetes, especially those with a postinduction glucose level <110 mg/dL.

Histidine-rich glycoprotein as a novel predictive biomarker of postoperative complications in intensive care unit patients: a prospective observational study.

BACKGROUND: Decrease in histidine-rich glycoprotein (HRG) was reported as a cause of dysregulation of the coagulation-fibrinolysis and immune systems, leading to multi-organ failure, and it may be a biomarker for sepsis, ventilator-associated pneumonia, preeclampsia, and coronavirus disease 2019. However, the usefulness of HRG in perioperative management remains unclear. This study aimed to assess the usefulness of HRG as a biomarker for predicting postoperative complications. METHODS: This was a single-center, prospective, observational study of 150 adult patients who were admitted to the intensive care unit after surgery. Postoperative complications were defined as those having a grade II or higher in the Clavien-Dindo classification, occurring within 7 days after surgery. The primary outcome was HRG levels in the patients with and without postoperative complications. The secondary outcome was the ability of HRG, white blood cell, C-reactive protein, procalcitonin, and presepsin to predict postoperative complications. Data are presented as number and median (interquartile range). RESULTS: The incidence of postoperative complications was 40%. The HRG levels on postoperative day 1 were significantly lower in patients who developed postoperative complications (n = 60; 21.50 [18.12-25.74] µg/mL) than in those who did not develop postoperative complications (n = 90; 25.46 [21.05-31.63] µg/mL). The Harrell C-index scores for postoperative complications were HRG, 0.65; white blood cell, 0.50; C-reactive protein, 0.59; procalcitonin, 0.73; and presepsin, 0.73. HRG was independent predictor of postoperative complications when adjusted for age, the presence of preoperative cardiovascular comorbidities, American Society of Anesthesiologists Physical Status Classification, operative time, and the volume of intraoperative bleeding (adjusted hazard ratio = 0.94; 95% confidence interval, 0.90-0.99). CONCLUSIONS: The HRG levels on postoperative day 1 could predict postoperative complications. Hence, HRG may be a useful biomarker for predicting postoperative complications.

Association between the Remifentanil Dose during Anesthesia and Postoperative pain.

Remifentanil is an ultra-short-acting opioid that sometimes causes opioid-induced hyperalgesia, which has led to controversy regarding the association between intraoperative remifentanil administration and postoperative pain. This study aimed to assess the effects of the intraoperative remifentanil dose on postoperative pain. Patients undergoing esophageal, gastric/hepatobiliary, or intestinal/colon surgery and using postoperative patient-controlled epidural analgesia were analyzed. The patients were divided into two groups based on the average intraoperative remifentanil dose (high-dose remifentanil [HR] group: ≥0.1 µg/kg/min; low-dose remifentanil [LR] group: <0.1 µg/kg/min). In all, 406 patients met the inclusion criteria. A significant difference in the average dose of remifentanil was seen between the groups during the anesthesia period (0.14±0.05 vs. 0.07±0.02 µg/kg/min). However, no significant difference was seen in pre- or intraoperative patient characteristics. Numerical rating scale (NRS) scores on postoperative day 1 were similar between the groups (HR: 1.7±2.0; LR: 1.7±2.0; p=0.74). The incidence of poor pain control (NRS > 3/10) was also similar between the groups (HR: 14%; LR: 16%; p=0.57). Older age (> 60 years) and type of surgery (esophageal surgery) were associated with worse postoperative NRS scores. No significant association was seen between the intraoperative remifentanil dose and postoperative NRS scores following thoracoabdominal surgery with postoperative epidural pain management.

Correlation between Mean Arterial Pressure and Regional Cerebral Oxygen Saturation on Cardiopulmonary Bypass in Pediatric Cardiac Surgery.

Some pediatric cardiac patients might experience low regional cerebral oxygen saturation (rSO2) during surgery. We investigated whether a pediatric patient's mean arterial pressure (MAP) can affect the rSO2 value during cardiopulmonary bypass (CPB). We retrospectively analyzed the cases of the pediatric patients who underwentcardiac surgery at our hospital (Jan. -Dec. 2019; n=141). At each MAP stage, we constructed line charts through the mean of the rSO2 values corresponding to each MAP and then calculated the correlation coefficients. We next divided the patients into age subgroups (neonates, infants, children) and into cyanotic congenital heart disease (CHD) and acyanotic CHD groups and analyzed these groups in the same way. The analyses of all 141 patients revealed that during CPB the rSO2 value increased with an increase in MAP (r=0.1626). There was a correlation between rSO2 and MAP in the children (r=0.2720) but not in the neonates (r=0.06626) or infants (r=0.05260). Cyanotic CHD or acyanotic CHD did not have a significant effect on the rSO2/MAP correlation. Our analysis demonstrated different patterns of a correlation between MAP and rSO2 in pediatric cardiac surgery patients, depending on age. MAP was positively correlated with rSO2 typically in children but not in neonate or infant patients.

Intraoperative Hypothermia Is Not Associated with Surgical Site Infections after Total Hip or Knee Arthroplasty.

Maintaining perioperative normothermia decreases the post-surgery surgical site infection (SSI) rate. We investigated whether SSI is associated with intraoperative hypothermia in total hip (THA) and total knee (TKA) arthroplasties by retrospectively analyzing 297 THA and TKA cases. The patients' intraoperative core body temperature (BT) was measured by bladder catheter or forehead sensor. We evaluated the associations between SSI and intraoperative BT and other variables and patient characteristics. Fifty-six patients (18.8%) had hypothermia (BT <36°C); 43 developed SSI (14.5%); only five had hypothermia (11.6%). Intraoperative hypothermia and SSI were not significantly associated. The SSI group had more men (34.9% vs. 18.1%) and THA patients (77.4%), a longer mean surgical duration (174.3 vs. 143.5 mins), and a higher average BT (36.4°C vs. 36.2°C) than the no-SSI group. The SSI patients had a higher intraoperative BT. A multivariable analysis revealed that SSI was associated with male sex (OR 2.3, 95%CI: 1.031-4.921, p=0.042), longer surgery (OR, 1.01, 95%CI: 1.003-1.017, p=0.004), THA (OR 3.6, 95%CI: 1.258-10.085, p=0.017), and intraoperative BT >36.0°C (OR 3.6, 95%CI: 1.367-9.475, p=0.009). Intraoperative hypothermia was not associated with SSI in adults who underwent THA or TKA. These results suggest that hypothermia might not be the problem for SSI.

Intrathecal Administration of the α1 Adrenergic Antagonist Phentolamine Upregulates Spinal GLT-1 and Improves Mirror Image Pain in SNI Model Rats.

Mirror image pain (MIP) is a type of extraterritorial pain that results in contralateral pain or allodynia. Glutamate transporter-1 (GLT-1) is expressed in astrocytes and plays a role in maintaining low glutamate levels in the synaptic cleft. Previous studies have shown that GLT-1 dysfunction induces neuropathic pain. Our previous study revealed bilateral GLT-1 downregulation in the spinal cord of a spared nerve injury (SNI) rat. We hypothesized that spinal GLT-1 is involved in the mechanism of MIP. We also previously demonstrated noradrenergic GLT-1 regulation. Therefore, this study aimed to investigate the effect of an α1 adrenergic antagonist on the development of MIP. Rats were subjected to SNI. Changes in pain behavior and GLT-1 protein levels in the SNI rat spinal cords were then examined by intrathecal administration of the α1 adrenergic antagonist phentolamine, followed by von Frey test and western blotting. SNI resulted in the development of MIP and bilateral downregulation of GLT-1 protein in the rat spinal cord. Intrathecal phentolamine increased contralateral GLT-1 protein levels and partially ameliorated the 50% paw withdrawal threshold in the contralateral hind paw. Spinal GLT-1 upregulation by intrathecal phentolamine ameliorates MIP. GLT-1 plays a role in the development of MIPs.

Association between intraoperative hyperglycemia and postoperative end-organ dysfunctions after cardiac surgery: a retrospective observational study.

PURPOSE: Hyperglycemia has been associated with postoperative morbidity in patients who undergo cardiac surgery. However, it remains unclear whether the duration of hyperglycemia is as important as its magnitude in the development of postoperative end-organ dysfunction (PEOD). This retrospective study investigated the hypothesis that the intraoperative blood glucose (BG) exposure index (GE index), calculated by the product of the magnitude and duration of BG concentration ≥ 180 mg/dL, which is an integration of the severity and duration of hyperglycemia, is associated with the incidence of PEOD in patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: The primary outcome in this study was PEOD within 72 h of surgery, which was defined as a composite of postoperative acute kidney injury, delirium, myocardial injury, and prolonged mechanical ventilation. The GE index (the magnitude of BG concentration deviation ≥ 180 mg/dL [Formula: see text] duration of BG concentration ≥ 180 mg/dL) of each patient was calculated based on the intraoperative BG concentration. The relationship between the GE index and the primary outcome was examined via logistic regression model with adjustment for potential confounders. RESULTS: Within 72 h of surgery, 301 patients (54.5%) developed PEOD. PEOD was more common in patients with greater GE index quartiles (first versus third quartile; adjusted odds ratio, 5.65, 95% confidence interval (95% CI), 2.94-10.90; P < 0.001; first versus forth quartile, adjusted odds ratio, 20.80; 95% CI, 8.01-54.00; P < 0.001). CONCLUSION: In patients undergoing cardiac surgery with cardiopulmonary bypass, the GE index was an independent predictor of PEOD.

Integrated pulmonary index can predict respiratory compromise in high-risk patients in the post-anesthesia care unit: a prospective, observational study.

BACKGROUND: Respiratory compromise (RC) including hypoxia and hypoventilation is likely to be missed in the postoperative period. Integrated pulmonary index (IPI) is a comprehensive respiratory parameter evaluating ventilation and oxygenation. It is calculated from four parameters: end-tidal carbon dioxide, respiratory rate, oxygen saturation measured by pulse oximetry (SpO2), and pulse rate. We hypothesized that IPI monitoring can help predict the occurrence of RC in patients at high-risk of hypoventilation in post-anesthesia care units (PACUs). METHODS: This prospective observational study was conducted in two centers and included older adults (≥ 75-year-old) or obese (body mass index ≥ 28) patients who were at high-risk of hypoventilation. Monitoring was started on admission to the PACU after elective surgery under general anesthesia. We investigated the onset of RC defined as respiratory events with prolonged stay in the PACU or transfer to the intensive care units; airway narrowing, hypoxemia, hypercapnia, wheezing, apnea, and any other events that were judged to require interventions. We evaluated the relationship between several initial parameters in the PACU and the occurrence of RC. Additionally, we analyzed the relationship between IPI fluctuation during PACU stay and the occurrences of RC using individual standard deviations of the IPI every five minutes (IPI-SDs). RESULTS: In total, 288 patients were included (199 elderly, 66 obese, and 23 elderly and obese). Among them, 18 patients (6.3 %) developed RC. The initial IPI and SpO2 values in the PACU in the RC group were significantly lower than those in the non-RC group (6.7 ± 2.5 vs. 9.0 ± 1.3, p < 0.001 and 95.9 ± 4.2 % vs. 98.3 ± 1.9 %, p = 0.040, respectively). We used the area under the receiver operating characteristic curves (AUC) to evaluate their ability to predict RC. The AUCs of the IPI and SpO2 were 0.80 (0.69-0.91) and 0.64 (0.48-0.80), respectively. The IPI-SD, evaluating fluctuation, was significantly greater in the RC group than in the non-RC group (1.47 ± 0.74 vs. 0.93 ± 0.74, p = 0.002). CONCLUSIONS: Our study showed that low value of the initial IPI and the fluctuating IPI after admission to the PACU predict the occurrence of RC. The IPI might be useful for respiratory monitoring in PACUs and ICUs after general anesthesia.