Neonatal administration of a subanaesthetic dose of JM-1232(-) in mice results in no behavioural deficits in adulthood.

In animal models, neonatal exposure of general anaesthetics significantly increases apoptosis in the brain, resulting in persistent behavioural deficits later in adulthood. Consequently, there is growing concern about the use of general anaesthetics in obstetric and paediatric practice. JM-1232(-) has been developed as a novel intravenous anaesthetic, but the effects of JM-1232(-) on the developing brain are not understood. Here we show that neonatal administration of JM-1232(-) does not lead to detectable behavioural deficits in adulthood, contrarily to other widely-used intravenous anaesthetics. At postnatal day 6 (P6), mice were injected intraperitoneally with a sedative-equivalent dose of JM-1232(-), propofol, or midazolam. Western blot analysis of forebrain extracts using cleaved poly-(adenosine diphosphate-ribose) polymerase antibody showed that JM-1232(-) is accompanied by slight but measurable apoptosis 6 h after administration, but it was relatively small compared to those of propofol and midazolam. Behavioural studies were performed in adulthood, long after the neonatal anaesthesia, to evaluate the long-term effects on cognitive, social, and affective functions. P6 administration to JM-1232(-) was not accompanied by detectable long-term behavioural deficits in adulthood. However, animals receiving propofol or midazolam had impaired social and/or cognitive functions. These data suggest that JM-1232(-) has prospects for use in obstetric and paediatric practice.

Extracellular signal-regulated kinases 2 (Erk2) and Erk5 in the central nervous system differentially contribute to central sensitization in male mice.

Nervous systems are designed to become extra sensitive to afferent nociceptive stimuli under certain circumstances such as inflammation and nerve injury. How pain hypersensitivity comes about is key issue in the field since it ultimately results in chronic pain. Central sensitization represents enhanced pain sensitivity due to increased neural signaling within the central nervous system (CNS). Particularly, much evidence indicates that underlying mechanism of central sensitization is associated with the change of spinal neurons. Extracellular signal-regulated kinases have received attention as key molecules in central sensitization. Previously, we revealed the isoform-specific function of extracellular signal-regulated kinase 2 (Erk2) in spinal neurons for central sensitization using mice with Cre-loxP-mediated deletion of Erk2 in the CNS. Still, how extracellular signal-regulated kinase 5 (Erk5) in spinal neurons contributes to central sensitization has not been directly tested, nor is the functional relevance of Erk5 and Erk2 known. Here, we show that Erk5 and Erk2 in the CNS play redundant and/or distinct roles in central sensitization, depending on the plasticity context (cell types, pain types, time, etc.). We used male mice with Erk5 deletion specifically in the CNS and found that Erk5 plays important roles in central sensitization in a formalin-induced inflammatory pain model. Deletion of both Erk2 and Erk5 leads to greater attenuation of central sensitization in this model, compared to deletion of either isoform alone. Conversely, Erk2 but not Erk5 plays important roles in central sensitization in neuropathic pain, a type of chronic pain caused by nerve damage. Our results suggest the elaborate mechanisms of Erk signaling in central sensitization.

Comparison of 1-year recurrence-free survival between sevoflurane and propofol use for general anesthesia management in primary breast cancer surgery.

PURPOSE: We evaluated the influence of anesthetic management with sevoflurane or propofol on recurrence in patients undergoing breast cancer surgery. METHODS: This single center, retrospective study, included patients who received either sevoflurane or propofol during primary breast cancer surgery between 2008 and 2012. Our primary outcome was recurrence-free survival (RFS) at 1 year. Recurrence was defined as locoregional recurrence and distal metastasis. Propensity scores were calculated using seven variables (age, sex, body mass index, cancer stage, tumor size, intrinsic subtype, and deviation from standard therapy), and Kaplan-Meier survival curves were constructed from the date of diagnosis of recurrence. Hazard ratios (HRs) were estimated using univariable Cox proportional hazard regression analysis. RESULTS: Two-hundred-twelve patients received sevoflurane and 814 patients received total intravenous anesthesia with propofol. The median follow-up was 59 (interquartile range, 44-75) months. Regional anesthetic techniques were not used. Recurrence occurred in 95 patients (9.26%), with 19 (8.96%) and 76 (9.33%) in the sevoflurane and propofol groups, respectively. The HR was 1.167 (95% confidence interval, 0.681-2.000, p = 0.574) for the use of sevoflurane over propofol. After 1:1 propensity-score matching, 318 patients were analyzed. The 1-year RFS rates were similar between the groups (sevoflurane group: 7.5% [n = 12], propofol group: 8.2% [n = 13]), yielding an HR of 1.002 (95% confidence interval 0.457-2.198, p = 0.995) associated with the use of sevoflurane over propofol. CONCLUSION: In patients undergoing primary breast cancer surgery, the use of either sevoflurane or propofol without regional anesthesia did not appear to affect the risk of recurrence after 1 year.

Efficacy of artificial pneumothorax under two-lung ventilation in video-assisted thoracoscopic surgery for esophageal cancer.

BACKGROUND: One-lung ventilation (OLV) is the standard and widely applied ventilation approach used in video-assisted thoracoscopic surgery for esophageal cancer (VATS-e). To address the disadvantages of OLV with respect to difficulties in intubation and induction, as well as the risk of respiratory complications, two-lung ventilation (TLV) with artificial pneumothorax has been introduced for use in VATS-e. However, no studies have yet compared TLV and OLV with postoperative infection and inflammation in the prone position over time postoperatively. Here, we investigated the efficacy of TLV in patients undergoing VATS-e in the prone position. METHODS: Between April 2010 and December 2016, 119 patients underwent VATS-e under OLV or TLV with carbon dioxide insufflation. Clinical characteristics, surgical outcomes, and postoperative outcomes, including oxygenation and systemic inflammatory responses, were compared between patients who underwent OLV and those who underwent TLV. RESULTS: Clinical characteristics other than pT stage were comparable between groups. The TLV group had shorter thoracic operation time than the OLV group. No patients underwent conversion to open thoracotomy. The PaO2/FiO2 ratios of the TLV group on postoperative day (POD) 5 and on POD7 were significantly higher than those of the OLV group. C-reactive protein levels on POD7 were lower in the TLV group than in the OLV group. There were no significant differences with respect to postoperative complications between the OLV and TLV groups. In the TLV group, the white blood cell count on POD7 was significantly lower than that in the OLV group; body temperature showed a similar trend immediately after surgery and on POD1. CONCLUSIONS: In this study, we demonstrated that, compared with OLV, TLV in the prone position provides better oxygenation and reduced inflammation in the postoperative course. Accordingly, TLV might be more useful than OLV for ventilation during esophageal cancer surgery.

The Effectiveness and Stability of a 20% Emulsified Sevoflurane Formulation for Intravenous Use in Rats.

BACKGROUND: Halogenated volatile anesthetics can be safely and rapidly administered to animals and humans using emulsion formulations. However, they must be administered simultaneously with a high dose of lipids. Increasing the concentration of volatile anesthetics may solve this clinical issue. Moreover, careful observation is needed when the emulsion is injected because anaphylactic reactions have been reported. METHODS: We prepared a 20% sevoflurane lipid emulsion and administered it to 69 male Sprague-Dawley rats via the tail vein. The median effective dose (ED50) for the loss of righting reflex and the median lethal dose (LD50) were determined. ED50 and LD50 values were calculated using nonlinear regression, and data were fitted with a cumulative Gaussian model using GraphPad Prism. Measurements of vital signs and evaluation of the presence of adverse effects associated with continuous infusion of emulsions were verified. Stability of the emulsion was assessed by measuring particle size at 365 days and sevoflurane concentrations after opening the vial at 180 minutes. RESULTS: The ED50 and LD50 were 0.47 mL/kg (95% confidence interval [CI], 0.46-0.48) and 1.13 mL/kg (95% CI, 1.07-1.18), respectively. The therapeutic index (LD50/ED50) was 2.41 (95 CI%, 2.23-2.59), which compares favorably with therapeutic index of a fluoropolymer-based emulsion of sevoflurane, propofol, and thiopental. There were no adverse effects associated with the continuous infusion of emulsions. Particle size of the emulsion at 365 days after preparation was 78.9 ± 3.8 nm (±SD), and sevoflurane concentration at 180 minutes after opening the vial was 19.0% ± 0.6% (±SD). CONCLUSIONS: We prepared a 20% sevoflurane lipid emulsion using caprylic triglyceride (i.e., medium-chain triglyceride). In rats, this emulsion was an effective anesthetic and was not associated with adverse events. The emulsion was stable after consecutive evaluation for 365 days and for 180 minutes after the vial was opened.

Comparison of a new cardiac output ultrasound dilution method with thermodilution technique in adult patients under general anesthesia.

OBJECTIVE: The purpose of this study was to investigate the reliability of cardiac output (CO) measured by a new ultrasound dilution method (COud) in comparison with CO by pulmonary artery thermodilution (COtd) in adult patients undergoing surgery. DESIGN: A prospective study. SETTING: A university hospital, single institutional. PARTICIPANTS: Twenty-nine adult patients undergoing abdominal surgery. MEASUREMENTS AND MAIN RESULTS: After approval of the institutional ethics review board, 29 adult patients were evaluated. After induction, radial and pulmonary artery catheters were inserted. A disposable extracorporeal AV loop was connected between existing arterial and central venous catheters. Reusable ultrasound sensors that measure changes in blood ultrasound velocity after dilution by isotonic saline were clamped onto the arterial and venous limbs of the loop. Ultrasound dilution (UD) measurements (COstatus; Transonic Systems, Inc, Ithaca, NY) were obtained by injecting 30 mL of body-temperature isotonic saline into the venous limb of the AV loop. An average of 3 COud and 5 COtd was obtained for comparison. Bland-Altman plot and correlation analysis were used for statistical comparison. A total of 142 comparison measurements were obtained. The correlation coefficient between the 2 techniques was r = 0.91. Bland-Altman analysis did not produce any significant bias (bias = 0.02, standard deviation = 0.56). The percentage error of these data was 23.53%. CONCLUSIONS: COud measurements agreed well with COtd. The results of this study indicated that COud might be interchangeable with conventional COtd in perioperative adult patients.

Comparison of predicted induction dose with predetermined physiologic characteristics of patients and with pharmacokinetic models incorporating those characteristics as covariates.

BACKGROUND: The relationship between patient characteristics and anesthesia induction dose at a high administration rate is unclear. This study was designed to investigate the relation between induction dose and patient characteristics and to compare it to the predicted induction dose using the previously reported pharmacokinetic model. METHODS: Diluted propofol (0.5 mg/ml) dose required to reach loss of consciousness, when infused at an infusion rate per lean body mass (LBM) of 150 mg x kg(-1) x h(-1) (high rate), was determined in 82 patients, ages 10-85 yr. Cardiac output, blood volume, central blood volume (CBV), and hepatic blood flow were measured with indocyanine green pulse spectrophotometry. Stepwise multiple linear regression models were used to investigate the relations between the patient characteristics and induction dose. These were compared with our previously reported parameters at the rate of 40 mg x kg(-1) x h(-1) (low rate) and with predicted induction doses with two previously reported pharmacokinetic models. RESULTS: Significant factors for predicting the induction dose at a high rate were age, LBM, and CBV. Induction dose with one pharmacokinetic model was 1.5 times that of the measured one and the other was half that of the measured one at a high rate. At a low rate, one pharmacokinetic model provided an accurate induction dose. CONCLUSIONS: The prediction of induction dose from physiologic characteristics of patients provides reasonable accuracy at both high and low administration rates of propofol. A previously reported pharmacokinetic model that incorporated patient characteristics provides the same accurate induction dose at a low rate.