Improvement of sleep and pain with lemborexant administration in patients with chronic pain: a retrospective observational study.

OBJECTIVE: Patients with chronic pain often have sleep disturbances, and many patients receive sleep medications in addition to analgesics. Although there have been scattered reports of negative pain-sleep interactions, only a few reports have investigated the efficacy of sleep medication interventions in patients with chronic pain for improving sleep disturbances and reducing pain. We retrospectively examined whether lemborexant, an orexin receptor antagonist, is effective in improving sleep disturbances and reducing pain in patients with chronic pain. This study was approved by the Ethics Committee of our hospital. METHODS: The subjects were 26 patients with chronic pain undergoing treatment at our pain clinic between July 2021 and March 2022, who had been diagnosed with insomnia, with an Athens Insomnia Scale (AIS) score of ≥6 and had been started on lemborexant. The AIS score and pain score (Numeric Rating Scale [NRS]) before and after 2 and 4 weeks of starting lemborexant were investigated. RESULTS: Patients who were already taking other sleep medications, such as benzodiazepines were switched to 5 mg of lemborexant after all the other sleep medications were discontinued. Those who had not yet used sleeping pills were started on 5 mg of lemborexant. During the study course, the dose of lemborexant was adjusted at the discretion of the attending physician, based on improvement of insomnia symptoms and secondary symptoms, such as daytime sleepiness and lightheadedness. The study finally included 21 patients, excluding 5 who could not continue taking lemborexant due to side effects, such as lightheadedness. The AIS scores significantly improved, decreasing from baseline (mean ± standard deviation: 12.5 ± 4.9) to 2 weeks (7.8 ± 3.1) and 4 weeks (5.3 ± 2.9) after the start of lemborexant. No significant difference was observed in the degree of improvement in sleep disturbance between patients with or without previous sleep medications, and there was also no statistically significant improvement in the NRS score before (6.1 ± 2.7) and after 2 weeks (5.5 ± 2.3) and 4 weeks (5.9 ± 2.2) from treatment initiation.

Perioperative serum syndecan-1 concentrations in patients who underwent cardiovascular surgery with cardiopulmonary bypass and its association with the occurrence of postoperative acute kidney injury: a retrospective observational study.

BACKGROUND: Various factors can cause vascular endothelial damage during cardiovascular surgery (CVS) with cardiopulmonary bypass (CPB), which has been suggested to be associated with postoperative complications. However, few studies have specifically investigated the relationship between the degree of vascular endothelial damage and postoperative acute kidney injury (pAKI). The objectives of this study were to measure perioperative serum syndecan-1 concentrations in patients who underwent CVS with CPB, evaluate their trends, and determine their association with pAKI. METHODS: This was a descriptive and case‒control study conducted at the National University Hospital. Adult patients who underwent CVS with CPB at a national university hospital between March 15, 2016, and August 31, 2020, were included. Patients who were undergoing preoperative dialysis, had preoperative serum creatinine concentrations greater than 2.0 mg dl-1, who were undergoing surgery involving the descending aorta were excluded. The perioperative serum syndecan-1 concentration was measured, and its association with pAKI was investigated. RESULTS: Fifty-two patients were included. pAKI occurred in 18 (34.6%) of those patients. The serum syndecan-1 concentration increased after CPB initiation and exhibited bimodal peak values. The serum syndecan-1 concentration at all time points was significantly elevated compared to that after the induction of anesthesia. The serum syndecan-1 concentration at 30 min after weaning from CPB and on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.10 [1.01 to 1.21], P = 0.03]; OR = 1.16 [1.01 to 1.34], P = 0.04]; and the cutoff values of the serum syndecan-1 concentration that resulted in pAKI were 101.0 ng ml-1 (sensitivity = 0.71, specificity = 0.62, area under the curve (AUC) = 0.67 (0.51 to 0.83)) and 57.1 ng ml-1 (sensitivity = 0.82, specificity = 0.56, AUC = 0.71 (0.57 to 0.86)). Multivariate logistic regression analysis revealed that the serum syndecan-1 concentration on postoperative day 1 was associated with the occurrence of pAKI (OR = 1.02 [1.00 to 1.03]; P = 0.03). CONCLUSION: The serum syndecan-1 concentration at all time points was significantly greater than that after the induction of anesthesia. The serum syndecan-1 concentration on postoperative day 1 was significantly associated with the occurrence of pAKI. TRIAL REGISTRATION: This study is not a clinical trial and is not registered with the registry.

Effectiveness of remimazolam in preventing postoperative delirium in elderly patients with proximal femoral fractures.

PURPOSE: Elderly patients with proximal femoral fractures are known to be a high-risk group for postoperative delirium (POD). The aim of this study was to determine the association of the benzodiazepine drug remimazolam with POD in elderly patients with proximal femoral fractures. METHODS: In this single-center retrospective observational study, we included patients aged 65 years or older who underwent general anesthesia for proximal femoral fractures. We collected data for the incidence of POD within 3 days after surgery. We also obtained data for complications, preoperative blood examinations, maintenance anesthetic and intraoperative vital data. The occurrence of POD in patients who received remimazolam for general anesthesia (remimazolam group) was compared to that in patients who received general anesthesia with other anesthetic agents (other group). We finally conducted a multivariate analysis to assess the independent association of remimazolam with the risk of POD. RESULTS: A total of 230 patients, including 54 patients who received remimazolam for maintenance anesthesia, were included in this study. The incidence of POD in the patients was 26.1%. The incidence of delirium within 3 days after surgery was significantly lower in the remimazolam group than in the other group (14.8% vs. 29.5%, p = 0.03). The multivariate analysis showed that the use of remimazolam independently reduced the occurrence of POD (adjusted odds ratio = 0.42, p = 0.04). CONCLUSION: This retrospective observational study showed that the use of remimazolam is independently associated with a reduced incidence of POD. Remimazolam may be considered as an option to reduce POD in elderly patients with proximal femoral fractures.

Rocuronium action can be affected by hyperventilation: a case report and computational simulation.

The neuromuscular blocking potency of rocuronium varies with respiratory pH changes, increasing at lower pH and decreasing at higher pH; thus, hyperventilation-induced respiratory alkalosis is expected to decrease the potency of rocuronium. We report a case of anesthetic management of modified electroconvulsive therapy (m-ECT) for a patient monitored with electromyography-based neuromuscular monitoring during two patterns of ventilation to elucidate their relationship and propose the possible mechanisms underlying the effects by computational simulations. Case presentation: The patient was a 25-year-old man with schizophrenia. In m-ECT, hyperventilation may be used to produce longer seizures. We compared the neuromuscular monitoring data recorded during hyperventilation and during normal ventilation while receiving the same dose of rocuronium. Despite receiving the same dose of rocuronium, the time required for the first twitch to decrease to 80% of the control value was delayed in hyperventilation compared to normal ventilation. Conclusions: This case report and computational simulation suggest that respiratory alkalosis might delay the action of rocuronium. It is necessary to consider the delayed action of rocuronium when hyperventilation is performed.

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.

Timing, Threshold, and Duration of Intraoperative Hypotension in Cardiac Surgery: Their Associations With Postoperative Delirium.

OBJECTIVES: To study the timing, threshold, and duration of intraoperative hypotension (IOH) associated with the risk of postoperative delirium (POD). DESIGN: A single-center retrospective observational study. SETTING: University teaching hospital. PARTICIPANTS: A total of 503 adult patients who underwent cardiac valvular surgery that required cardiopulmonary bypass (CPB). MEASUREMENTS AND MAIN RESULTS: The authors predefined the following 4 periods: (1) during surgery, (2) pre-CPB, (3) during CPB, and (4) post-CPB, and 8 thresholds of mean arterial pressure for IOH according to every 5 mmHg between 50 mmHg and 85 mmHg. The authors calculated the cumulative duration below the 8 thresholds in each period. The primary outcome was delirium defined as a score of ≥4 for at least one Intensive Care Delirium Screening Checklist assessment during 48 h after the surgery. Among 503 patients, POD occurred in 95 patients (18.9%). There was no significant association of POD with all of the thresholds of IOH in the periods of pre-CPB, during CPB, and during surgery. However, in the post-CPB period, the patients with POD had a significantly longer cumulative duration of IOH according to all of the thresholds of mean arterial pressure. In multivariate analyses, 4 IOH thresholds in the post-CPB period were associated independently with POD: <60 mmHg (odds ratio [OR] =1.84 [95% CI 1.10-3.10]), <65 mmHg (OR = 1.72 [1.01-2.92]), <70 mmHg (OR = 1.83 [1.03-3.26]), and <75 mmHg (OR = 1.94 [1.02-3.69]). CONCLUSIONS: A longer cumulative duration of IOH with the threshold between <60 and <75 mmHg that occurred after CPB was independently associated with the risk of POD.

SIRPα on CD11c+ cells induces Th17 cell differentiation and subsequent inflammation in the CNS in experimental autoimmune encephalomyelitis.

Signal regulatory protein α (SIRPα) is expressed predominantly on type 2 conventional dendritic cells (cDC2s) and macrophages. We previously showed that mice systemically lacking SIRPα were resistant to experimental autoimmune encephalomyelitis (EAE). Here, we showed that deletion of SIRPα in CD11c+ cells of mice (SirpaΔDC mice) also markedly ameliorated the development of EAE. The frequency of cDCs and migratory DCs (mDCs), as well as that of Th17 cells, were significantly reduced in draining lymph nodes of SirpaΔDC mice at the onset of EAE. In addition, we found the marked reduction in the number of Th17 cells and DCs in the CNS of SirpaΔDC mice at the peak of EAE. Whereas inducible systemic ablation of SIRPα before the induction of EAE prevented disease development, that after EAE onset did not ameliorate the clinical signs of disease. We also found that EAE development was partially attenuated in mice with CD11c+ cell-specific ablation of CD47, a ligand of SIRPα. Collectively, our results suggest that SIRPα expressed on CD11c+ cells, such as cDC2s and mDCs, is indispensable for the development of EAE, being required for the priming of self-reactive Th17 cells in the periphery as well as for the inflammation in the CNS.

Perioperative Serum Free Hemoglobin and Haptoglobin Levels in Valvular and Aortic Surgery With Cardiopulmonary Bypass: Their Associations With Postoperative Kidney Injury.

OBJECTIVE: To observe the perioperative free hemoglobin and haptoglobin levels and to assess their associations with the risk of postoperative acute kidney injury (pAKI) in adult patients undergoing valvular and aortic surgery requiring cardiopulmonary bypass (CPB). DESIGN: A single-center, prospective, observational study. SETTING: Public teaching hospital. PARTICIPANTS: The study comprised 74 adult patients without chronic renal failure who underwent cardiovascular surgery requiring CPB from 2014 to 2020. MEASUREMENTS AND MAIN RESULTS: Perioperative free hemoglobin and haptoglobin levels during the study period were obtained from study participants. The primary outcome was pAKI defined by the Kidney Disease: Improving Global Outcomes criteria. Of the 74 patients in this study, pAKI occurred in 25 patients (33.8%). The free hemoglobin level began to increase after the initiation of CPB and reached a peak level at 30 minutes after weaning from CPB. It returned to the baseline level on postoperative day one. Haptoglobin levels were the highest after anesthesia induction and decreased continuously until postoperative day one. In the multivariate analysis, maximum free hemoglobin and minimum haptoglobin were associated independently with increased risk of pAKI (adjusted odds ratio 1.33 [95% confidence interval 1.12-1.58; p = 0.001] and 0.95 [95% confidence interval 0.91-1.00; p = 0.03], respectively). The free hemoglobin level began to have an independent association with pAKI at one hour after commencement of CPB, and the independent association disappeared at postoperative day one. CONCLUSIONS: This study found that the perioperative increase of the free hemoglobin level and the decrease of the haptoglobin level had independent associations with the risk of pAKI.

Suppression of behavioral activity and hippocampal noradrenaline caused by surgical stress in type 2 diabetes model mice.

BACKGROUND: There has been much discussion recently about the occurrence of neuropsychological complications during the perioperative period. Diabetes is known to be one of the metabolic risk factors. Although the number of patients with diabetes mellitus (DM) has been increasing, the pathophysiology of postoperative neuropsychological dysfunction in DM patients is still unclear. Recently, a deficiency of neurotransmitters, such as monoamines, was reported to be associated with mental disorders. Therefore, we investigated the effects of surgical stress on behavioral activity and hippocampal noradrenaline (NA) level in type 2 diabetes mellitus model (T2DM) mice. METHODS: Eighty-four 6-week-old male C57BL/6J mice were divided into four groups (non-diabetes, non-diabetes with surgery, T2DM, and T2DM with surgery groups). T2DM mice were established by feeding a high-fat diet (HFD) for 8 weeks. At 14 weeks of age, fifteen mice in each group underwent a series of behavioral tests including an open field (OF) test, a novel object recognition (NOR) test and a light-dark (LD) test. In the surgery groups, open abdominal surgery with manipulation of the intestine was performed 24 h before the behavioral tests as a surgical stress. Hippocampal noradrenaline (NA) concentration was examined in six mice in each group by high-performance liquid chromatography. The data were analyzed by the Mann-Whitney U test, and p values less than 0.05 were considered significant. RESULTS: The T2DM group showed significantly increased explorative activity in the NOR test (P = 0.0016) and significantly increased frequency of transition in the LD test (P = 0.043) compared with those in the non-diabetic group before surgery. In T2DM mice, surgical stress resulted in decreased total distance in the OF test, decreased explorative activity in the NOR test, and decreased frequency of transition in the LD test (OF: P = 0.015, NOR: P = 0.009, LD: P = 0.007) and decreased hippocampal NA (P = 0.015), but such differences were not observed in the non-diabetic mice. CONCLUSIONS: Mice with T2DM induced by feeding an HFD showed increased behavioral activities, and surgical stress in T2DM mice caused postoperative hypoactivity and reduction of the hippocampal NA level.

Long-term preoperative glycemic control restored the perioperative neutrophilic phagocytosis activity in diabetic mice.

BACKGROUND: The risk of surgical site infection has been reported to be higher in patients with poorly controlled diabetes. Since chronic hyperglycemia impairs neutrophil functions, preoperative glycemic control may restore neutrophil function. However, long-term insulin therapy may lead to a delay in surgery, which may be a problem, especially in cancer surgery. It is therefore unfortunate that there have been few studies in which the optimal duration of perioperative glycemic control for diabetes with chronic hyperglycemia was investigated. Therefore, we investigated the effects of preoperative long-term insulin therapy and short-term insulin therapy on perioperative neutrophil functions in diabetic mice with chronic hyperglycemia. METHODS: Five-week-old male C57BL/6 J mice were divided into four groups (No insulin (Diabetes Mellitus: DM), Short-term insulin (DM), Long-term insulin (DM), and Non-diabetic groups). Diabetes was established by administrating repeated low-dose streptozotocin. The Short-term insulin (DM) group received insulin therapy for 6 h before the operation and the Long-term insulin (DM) group received insulin therapy for 5 days before the operation. The No insulin (DM) group and the Non-diabetic group did not receive insulin therapy. At 14 weeks of age, abdominal surgery with intestinal manipulation was performed in all four groups. We carried out a phagocytosis assay with fluorescent microspheres and a reactive oxygen species (ROS) production assay with DCFH-DA (2',7'-dichlorodihydrofluorescein diacetate) before and 24 h after the operation using FACSVerse™ with BD FACSuite™ software. RESULTS: Blood glucose was lowered by insulin therapy in the Short-term insulin (DM) and Long-term insulin (DM) groups before the operation. Neutrophilic phagocytosis activities before and after the operation were significantly restored in the Long-term insulin (DM) group compared with those in the No insulin (DM) group (before: p = 0.0008, after: p = 0.0005). However, they were not significantly restored in the Short-term insulin (DM) group. Neutrophilic ROS production activities before and after the operation were not restored in either the Short-term insulin (DM) group or Long-term insulin (DM) group. CONCLUSIONS: Preoperative and postoperative phagocytosis activities are restored by insulin therapy for 5 days before the operation but not by insulin therapy for 6 h before the operation.

The association of intraoperative end-tidal carbon dioxide with the risk of postoperative nausea and vomiting.

PURPOSE: Patients undergoing gynecological surgery are considered to be a high-risk cohort for postoperative nausea and vomiting (PONV). The purpose of this study was to assess the association of intraoperative end-tidal carbon dioxide (EtCO2) with risk of PONV in patients underwent gynecological open surgery. METHODS: In this single-center retrospective observational study, we included patients aged 20-60 years who underwent elective gynecological open surgery. We obtained data for the incidence of PONV within 24 h after operation. We collected EtCO2 every minute during the operation, and determined the lowest value of EtCO2. We compared the lowest EtCO2 between patients with and without PONV. Multivariate logistic regression analysis was performed to assess the independent association of EtCO2 with the risk of PONV. RESULTS: A total of 146 patients were included in the current study. There were 81 patients with PONV within 24 h after the operation. The median lowest value of EtCO2 in patients with PONV was significantly lower than that in patients without PONV (31 vs 33 mmHg, p = 0.02). In the multivariate logistic regression model, we found that lowest EtCO2 ≤ 31 mmHg was independently associated with increase in the risk of PONV (adjusted odds ratio = 3.37, p = 0.02). CONCLUSION: In this retrospective observational study, low intraoperative EtCO2 was shown to be independently associated with increased risk of PONV. However, this result may be skewed by uncollected information including previous PONV, motion sickness or other unknown bias, so future studies should be conducted to refute or confirm our findings.

The impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients: retrospective before-after observational study.

PURPOSE: To assess the impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients, we conducted retrospective before-after study in a tertiary teaching hospital. METHODS: We examined all adult patients admitted ICU after an elective operation for head and neck cancer, or esophageal cancer from February 2014 to January 2017. From February 2014 to July 2015, patients were administered hypotonic fluid (sodium; 35 mmol/L) as the National Institute for Health and Care Excellence (NICE) have recommended. From August 2015 to January 2017, patients were administered isotonic fluid (sodium; 140 mmol/L). We defined the incidence of delirium as the primary outcome. The delirium was defined as the Intensive Care Delirium Screening Checklist during the ICU stay ≥ 4. A propensity score-matched model was used to adjust confounders. RESULTS: As postoperative intravenous maintenance fluid, hypotonic fluid was administered to 119 patients and isotonic fluid was administered to 92 patients. Among those total cohorts, the incidence of postoperative delirium in the hypotonic group was 21.8%, which was significantly higher than that (9.8%) in the isotonic group (p = 0.019). After propensity score matching, we selected 77 patients in each group. The incidence of delirium during the ICU stay in the hypotonic group was 26.0%, which was significantly higher than the incidence of 11.7% in the isotonic group (p = 0.023). CONCLUSIONS: In this study, the use of postoperative hypotonic maintenance fluid was associated with a higher risk of postoperative delirium than that when isotonic maintenance fluid was used.

Current Ventilator and Oxygen Management during General Anesthesia: A Multicenter, Cross-sectional Observational Study.

BACKGROUND: Intraoperative oxygen management is poorly understood. It was hypothesized that potentially preventable hyperoxemia and substantial oxygen exposure would be common during general anesthesia. METHODS: A multicenter, cross-sectional study was conducted to describe current ventilator management, particularly oxygen management, during general anesthesia in Japan. All adult patients (16 yr old or older) who received general anesthesia over 5 consecutive days in 2015 at 43 participating hospitals were identified. Ventilator settings and vital signs were collected 1 h after the induction of general anesthesia. We determined the prevalence of potentially preventable hyperoxemia (oxygen saturation measured by pulse oximetry of more than 98%, despite fractional inspired oxygen tension of more than 0.21) and the risk factors for potentially substantial oxygen exposure (fractional inspired oxygen tension of more than 0.5, despite oxygen saturation measured by pulse oximetry of more than 92%). RESULTS: A total of 1,786 patients were found eligible, and 1,498 completed the study. Fractional inspired oxygen tension was between 0.31 and 0.6 in 1,385 patients (92%), whereas it was less than or equal to 0.3 in very few patients (1%). Most patients (83%) were exposed to potentially preventable hyperoxemia, and 32% had potentially substantial oxygen exposure. In multivariable analysis, old age, emergency surgery, and one-lung ventilation were independently associated with increased potentially substantial oxygen exposure, whereas use of volume control ventilation and high positive end-expiratory pressure levels were associated with decreased potentially substantial oxygen exposure. One-lung ventilation was particularly a strong risk factor for potentially substantial oxygen exposure (adjusted odds ratio, 13.35; 95% CI, 7.24 to 24.60). CONCLUSIONS: Potentially preventable hyperoxemia and substantial oxygen exposure are common during general anesthesia, especially during one-lung ventilation. Future research should explore the safety and feasibility of a more conservative approach for intraoperative oxygen therapy.

Glycated hemoglobin A1c level on the day of emergency surgery is a marker of premorbid glycemic control: a retrospective observational study.

BACKGROUND: Current international guideline recommends to maintain blood glucose level ≤ 180 mg/dL in acute ill patients, irrespective of presence of premorbid diabetes. However, there are studies suggested that optimal acute glycemic control should be adjusted according to premorbid glycemic control in patients with chronic hyperglycemia. Accordingly, to obtain the information of premorbid glycemic control would be relevant. However, the HbA1c level on the day of the emergency operation (HbA1c-ope) might not be useful as a surrogate of premorbid chronic glycemic control, since glucose metabolism can be affected by inflammation, severity of illness and surgical invasion. METHODS: We hypothesized that HbA1c-ope reflects pre-morbid glycemic control. To assess this hypothesis, we conducted a single-center retrospective observational study to assess the association between HbA1c-ope and HbA1c level measured within 30 days before the operation (HbA1c-pre). We screened patients who had been admitted to the ICU of our hospital after emergency surgery during the period from January 2008 to December 2016. Patients in whom both of HbA1c-ope and HbA1c-pre were measured were included in this study. We compared HbA1c-ope and HbA1c-pre using the paired t-test. The correlation between the two HbA1c measurements was assessed using Pearson's correlation coefficient. Its agreement was assessed using the Bland-Altman approach with 95% confidence intervals. RESULTS: We included 48 patients in this study. The mean value of HbA1c-pre was 6.3%, which was not significantly different from the mean value of 6.2% for HbA1c-ope (p = 0.12). There was a significant correlation between HbA1c-pre and HbA1c-ope (r2 = 0.70, p < 0.001). The mean difference between two HbA1c measurements was 0.12% (95% CI: -0.03% to 0.27%). The limit of agreement ranged from - 0.9% to +1.1%. CONCLUSIONS: We found that there was a significant correlation between HbA1c-ope and HbA1c-pre. Our findings suggest that HbA1c-ope can be used to estimate previous glycemic control with an acceptable degree of accuracy, enabling personalized glycemic control in the perioperative period.

Haptoglobin Administration in Cardiovascular Surgery Patients: Its Association With the Risk of Postoperative Acute Kidney Injury.

BACKGROUND: Acute kidney injury (AKI) often occurs after cardiac surgery. During cardiac surgery, plasma free hemoglobin (fHb) would increase due to hemolysis. Since plasma fHb is thought to be nephrotoxic, haptoglobin, which is an fHb scavenger, may have the potential to prevent postoperative AKI (pAKI). However, there have been few studies in which the association of intraoperative administration of haptoglobin with the incidence of AKI after cardiac surgery was assessed. METHODS: This study was a retrospective observational study to assess the independent association of intraoperative administration of haptoglobin with the incidence pAKI in cardiac surgery patients. We screened cardiac surgery patients who required cardiopulmonary bypass from 2008 to 2015. We excluded patients who required renal replacement therapy preoperatively. We also excluded patients in whom descending aortic replacement was performed. pAKI was defined according to AKI Network criteria. A propensity score-matched model was used to adjust confounders. For sensitive analysis, we further developed a logistic regression model. RESULTS: We included 1326 patients in this study. The incidence of AKI in the total cohort was 25.5% (338 patients). Haptoglobin was administered in 260 patients (19.6%). In the crude cohort, the incidence of AKI in patients with haptoglobin administration was 24.6%, which was not significantly different from the incidence of 25.7% in those without haptoglobin administration (P = .72; odds ratio, 0.94 [95% confidence interval, 0.69-1.29]). After propensity score matching, we had 249 patients in each group (for a total of 498 patients). In this propensity score-matched cohort, the incidence of AKI in patients with haptoglobin administration was 22.5%, which was significantly lower than the incidence of 30.9% in those without haptoglobin administration (P = .033; odds ratio, 0.65 [0.43-0.97]). In our logistic regression model for the risk of pAKI, haptoglobin administration was independently associated with decreased risk of AKI (P = .029; adjusted odds ratio, 0.54 [0.31, 0.93]). CONCLUSIONS: In this hypothesis-generating, single-center retrospective observational study, intraoperative administration of haptoglobin was independently associated with lower risk of AKI after cardiovascular surgery.

Constant Current vs. Constant Voltage Systems for Temporal Spinal Cord Stimulation for Intractable Pain.

Although spinal cord stimulation (SCS) is a useful treatment for chronic intractable pain, the optimal method of stimulation has not yet been established. In this prospective, crossover study, we compared the efficacy of using a constant current (CC) system with that of a constant voltage (CV) system for temporal SCS. Twenty patients were enrolled and divided into two groups. For 10 patients, a CV system was applied on Days 1-5, followed by the use of a CC system on Days 6-10. For the other 10 patients, a CC system was applied for the first five days, followed by a CV system for the subsequent five days. We evaluated the alteration of pain intensity using a visual analogue scale (VAS), the area of stimulation, the stability of effect, and patient satisfaction regarding treatment. The pain scores decreased significantly after the start of the SCS. There was no significant difference in the change in VAS between the two systems. The stimulation method used for temporal SCS did not affect the reduction of pain intensity. Patients felt a wider stimulation area by the CC system compared to the CV system.

Comparison of the incidences of hyponatremia in adult postoperative critically ill patients receiving intravenous maintenance fluids with 140 mmol/L or 35 mmol/L of sodium: retrospective before/after observational study.

PURPOSE: The purpose of this study was to compare the incidences of hyponatremia in adult postoperative critically ill patients receiving isotonic and hypotonic maintenance fluids. METHODS: In this single-center retrospective before/after observational study, we included patients who had undergone an elective operation for esophageal cancer or for head and neck cancer and who received postoperative intensive care for >48 h from August 2014 to July 2016. In those patients, sodium-poor solution (35 mmol/L of sodium; Na35) had been administered as maintenance fluid until July 2015. From August 2015, the protocol for postoperative maintenance fluid was revised to the use of isotonic fluid (140 mmol/L of sodium; Na140). The primary outcome was the incidence of hyponatremia (<135 mmol/L) until the morning of postoperative day (POD) 2. RESULTS: We included 179 patients (Na35: 87 patients, Na140: 92 patients) in the current study. The mean volume of fluid received from ICU admission to POD 2 was not significantly different between the two groups (3291 vs 3337 mL, p = 0.84). The incidence of postoperative hyponatremia was 16.3% (15/92) in the Na140 cohort, which was significantly lower than that of 52.9% (46/87) in the Na35 group (odds ratio = 0.17, 95% confidence interval 0.09-0.35, p < 0.001]. The incidences of hypernatremia, defined as serum sodium concentration >145 mmol/L, were not significantly different between the two groups. CONCLUSION: In this study, the use of intravenous maintenance fluid with 35 mmol/L of sodium was significantly associated with an increased risk of hyponatremia compared to that with 140 mmol/L of sodium in adult postoperative critically ill patients.

Impact of Milrinone Administration in Adult Cardiac Surgery Patients: Updated Meta-Analysis.

OBJECTIVE: To determine the effects of milrinone on short-term mortality in cardiac surgery patients with focus on the presence or absence of heterogeneity of the effect. DESIGN: A systematic review and meta-analysis. SETTING AND PARTICIPANTS: Five hundred thirty-seven adult cardiac surgery patients from 12 RCTs. INTERVENTIONS: Milrinone administration. MEASUREMENTS AND MAIN RESULTS: The authors conducted a systematic Medline and Pubmed search to assess the effect of milrinone on short-term mortality in adult cardiac surgery patients. Subanalysis was performed according to the timing for commencement of milrinone administration and the type of comparators. The primary outcome was any short-term mortality. Overall analysis showed no difference in mortality rates in patients who received milrinone and patients who received comparators (odds ratio = 1.25, 95% CI 0.45-3.51, p = 0.67). In subanalysis for the timing to commence milrinone administration and the type of comparators, odds ratio for mortality varied from 0.19 (placebo as control drug, start of administration after cardiopulmonary bypass) to 2.58 (levosimendan as control drug, start of administration after cardiopulmonary bypass). CONCLUSIONS: Among RCTs to assess the effect of milrinone administration in adult cardiac surgery patients, there are wide variations of the odds ratios of administration of milrinone for short-term mortality according to the comparators and the timing of administration. This fact may suggest that a simple pooling meta-analysis is not applicable for assessing the risk and benefit of milrinone administration in an adult cardiac surgery cohort.

Effects of sevoflurane exposure during late pregnancy on brain development of offspring mice.

BACKGROUND: Exposure to some anesthetic agents during the fetal period has been shown to induce neurodegeneration or learning deficits in animal models. Sevoflurane is one of the most prevalent general anesthetics; however, the influence of sevoflurane at a clinically relevant concentration on the developing fetal brain remains unknown. OBJECTIVE: We investigated whether a single sevoflurane exposure during the fetal period would affect neuronal development and learning/memory ability in mice. METHODS: Pregnant mice at gestational day 17 were anesthetized with 1.5% sevoflurane in 50% oxygen for 6 h. Mice in the control group were exposed in 50% oxygen without sevoflurane. Pups of some mice in both groups subsequently were delivered early by cesarean section and whole fetal brains were excised. The rest of the pups were delivered naturally at gestational day 20 and were maintained for 8 weeks. The mRNA expression levels of caspase-3, brain derived neurotrophic factor (BDNF), nerve growth factor (NGF), and LIM kinase-1 (LIMK-1) were measured in fetal whole brain and 8-week-old hippocampus sections. Synaptophysin protein in adult hippocampus was assessed immunochemically. In addition, 8-week-old mice were subjected to the radial maze test. RESULTS: No significant difference between sevoflurane and control groups regarding mRNA expression levels of all targets was seen, nor was there an obvious change in synaptophysin protein expression. The results of the maze test revealed that the each-day performance ratios (the rate of errors) of the sevoflurane group were not altered as compared with the control group. CONCLUSIONS: These results suggest that the exposure during late pregnancy to a clinically relevant concentration of sevoflurane does not affect neuronal development and learning/memory ability of offspring mice.

Isoflurane Induces Transient Impairment of Retention of Spatial Working Memory in Rats.

Postoperative cognitive dysfunction (POCD) occurs in nearly one-third of patients after non-cardiac surgery. Many animal behavior studies have investigated the effect of general anesthesia on cognitive function. However, there have been no studies examining the effects on working memory specifically, with a focus on the retention of working memory. We demonstrate here that isoflurane anesthesia induces deficits in the retention of spatial working memory in rats, as revealed by an increase in isoflurane- induced across-phase errors in the delayed spatial win-shift (SWSh) task with a 30-min delay in an 8-arm radial arm maze on post-anesthesia days (PADs) 1,2,4, and 10. A post-hoc analysis revealed a significant increase in across-phase errors on PAD 1 and recovery on PAD 10 in the isoflurane group. In contrast, within-phase errors independent of the retention of working memory were unaffected by isoflurane. These results demonstrate that isoflurane anesthesia transiently impairs the retention of spatial working memory in rats.