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In priority-based two-sided matchings, a respecting-improvements property of a mechanism requires that an agent should get weakly better off when she is assigned a higher priority. Not only is it a normative desideratum, it is also important for ex-ante investments and for disclosure of non-preference information. In the general model of matching with contracts, we demonstrate that respect for improvements is closely related to strategy-proofness (with respect to preference information): With a number of different sets of assumptions and two definitions of improvements, a stable mechanism respects improvements if and ``almost'' only if it is strategy-proof, although the precise statements vary across different layers of our assumptions. Our results suggest that strategy-proofness is desirable not only as a strategic property, but also for its normative implication. We also provide a new sufficient condition for the cumulative offer mechanism to be strategy-proof, which also suffices for respect for improvements.

IntroductionPrevious studies explored the benefits related to early ambulation postoperatively, but few focused on patients with rheumatoid arthritis (RA). We retrospectively evaluated the incidence and predictors of the inability to begin walking on the first postoperative day (POD) after toe arthroplasty for rheumatoid arthritis.MethodsRA patients who underwent toe arthroplasty at one hospital were retrospectively reviewed. A total of 300 patients were included and divided into two groups: possible group (n= 191), who were able to walk on the first POD, and impossible group (n= 109), who were unable to walk on the first POD. Data were analyzed using odds ratios (OR) with 95% confidence intervals (CI) between various patient factors and the impossible group with logistic regression analysis.ResultsThe incidence of postoperative nausea and vomiting before rehabilitation was significantly associated with the infeasibility of walking rehabilitation on the first POD [OR = 2.43, 95% CI 1.22–4.14,P= 0.003]. The number of rescue analgesics administered before rehabilitation and the supplementation of peripheral nerve block was also associated with the infeasibility of walking rehabilitation on the first POD [OR = 1.29, 95% CI 1.04–1.59,P= 0.003; OR = 0.41, 95% CI 0.20–0.79,P= 0.010, respectively].ConclusionThe incidence of postoperative nausea and vomiting and inadequate postoperative pain management hindered early rehabilitation. Adding peripheral nerve block to general anesthesia had an advantage for postoperative rehabilitation after toe arthroplasty for rheumatoid arthritis.

Background: It is important to promote early ambulation postoperatively but there are many factors that can hinder the possibility of walking after surgery. Studies have been done to research the benefits related to early ambulation postoperatively but few are focused on patients that have rheumatoid arthritis (RA). We retrospectively investigated the incidence and predictors of the inability to start walking on the first postoperative day (POD) after rheumatoid toe arthroplasty.Methods: RA patients who underwent toe arthroplasty at an academic teaching hospital were retrospectively reviewed. We divided patients into the two groups: possible group, who were able to walk on the first day postoperatively and impossible group, who were unable to walk on the first day postoperatively. The primary outcome was odds ratio (OR) with a 95% confidence interval (CI) between various patient factors and the impossible group with logistic regression analysis. The post hoc analysis for association between anesthesia methods and postoperative outcome was carried out.Results: A total of 300 patients were included and divided into two groups: possible group (n = 191) and impossible group (n = 109). The incidence of postoperative nausea and vomiting (PONV) before rehabilitation was significantly associated with the infeasibility of walking rehabilitation on the first POD [OR = 2.43, 95% CI 1.22-4.14, P = 0.003]. The number of rescue analgesics administered before rehabilitation and the supplementation of peripheral nerve block (PNB) was also associated with the infeasibility of walking rehabilitation on the first POD [OR = 1.29, 95% CI 1.04-1.59, P = 0.003], [OR = 0.41, 95% CI 0.20-0.79, P = 0.010], respectively. In the post hoc analysis, incidence of PONV was highly associated with postoperative intravenous continuous opioid (48.7%, P < 0.0001) compared to regional analgesia; PNB (11.3 %) and epidural (26.7%).Conclusions: In our study, the incidence of PONV and inadequate postoperative pain management hindered early rehabilitation. Adding PNB to general anesthesia had an advantage for postoperative rehabilitation and decreased PONV after rheumatoid toe surgery.

In the standard matching with contracts setting, the unilateral substitutability condition (Hatfield and Kojima, 2010) is known to be sufficient for the guaranteed existence of a doctor-optimal stable allocation. We show that the same condition is indeed necessary under observable substitutability across doctors (Hatfield, Kominers and Westkamp, 2020) while also necessary in the maximal domain sense in general for its guaranteed existence.

We propose a new solution concept in the roommate problem, based on the “robustness” of deviations (i.e., blocking coalitions). We call a deviation from a matching robust up to depth k, if none of the deviators gets worse off than at the original matching after any sequence of at most k subsequent deviations. We say that a matching is stable against robust deviations (for short, SaRD) up to depth k, if no deviation from it is robust up to depth k. As a smaller k imposes a stronger requirement for a matching to be SaRD, we investigate the existence of a matching that is SaRD with a minimal depth k. We constructively demonstrate that a SaRD matching always exists for k=3 and establish sufficient conditions for k=1 and 2.

Purpose: The accuracy of spectrophotometric hemoglobin (SpHb) measurement with a pulse co-oximeter was analyzed in cases of intraoperative massive hemorrhage and compared with Hb levels determined through blood gas analysis (LabHb) as a reference. We aimed to determine the extent to which in vivo adjustment (ADJ) for results of initial blood gas analysis would improve the accuracy of SpHb measurement. Methods: Data on LabHb and SpHb levels were collected from cases with hemorrhage of 1000 g or more. Correlations and Bland-Altman analyses were used to determine the associations between data before and after ADJ. Results: ADJ slightly improved the correlation coefficient (Pearson r) between SpHb and LabHb levels from 0.65 to 0.72. In Bland-Altman analysis, ADJ reduced the bias from 1.76 ± 1.47 g/dL to 0.64 ± 1.43 g/dL, while the 95% limits of agreement of -1.12 to 4.64 g/dL (range: 5.77 g/dL) without ADJ improved to -2.16 to 3.44 g/dL (range: 5.59 g/dL) with ADJ. In four-quadrant analysis, other than samples in the exclusion zone, the total number analyzed was 326, and the concordance rate was 82%. Conclusion: Although the accuracy of SpHb measurement improves on ADJ, SpHb measurement cannot substitute for LabHb levels, and it is necessary to determine Hb levels with blood gas analysis in the laboratory. It remains unclear which measurement is superior for determining when to initiate blood transfusion to achieve better outcomes. To comply with conventional methods, LabHb measurements may be necessary.

Preventing intraoperatively acquired pressure ulcers (IAPUs) in patients undergoing spinal surgery in the prone position using a Relton-Hall frame is challenging. We investigated the efficacy of soft silicone foam dressings in preventing IAPUs. A prospective dual-center sham study was conducted among patients undergoing elective spinal surgery in a general hospital and a university hospital in Japan. The incidence of IAPUs that developed when soft silicone foam dressings and polyurethane film dressings were used was compared on two sides in the same patient. IAPUs developed on the chest in 11 of 100 patients (11%). Polyurethane film dressings were associated with a significantly higher rate of IAPUs than soft silicone foam dressings (11 versus 3, P = 0·027). A multivariate logistic regression analysis revealed that a diastolic blood pressure of

Objective To compare incidence of atrial arrhythmia, duration of care, and major complications after cardiac surgery between patients who received etomidate and those who received other induction agents. Design Retrospective cohort study utilizing propensity score matching. Setting A single academic, tertiary care hospital. Participants Eight thousand nine hundred seventy-eight patients undergoing coronary artery bypass grafting (CABG), valve, or combined valve/CABG surgery requiring cardiopulmonary bypass between January 2005 and December 2010. Interventions Patients were divided into those who received etomidate at anesthetic induction and those who received another induction agent. Patients given etomidate were propensity-score matched to patients given other induction agents in a 2:1 ratio. Measurements and Main Results Of 8,978 patients who underwent CABG, valve, or combined valve/surgery, 6,313 received etomidate and 2,665 received other induction agents. Among these, the authors successfully matched 4,094 etomidate patients with 2,524 non-etomidate patients. The authors did not find a significant association between receiving etomidate and odds of experiencing postoperative atrial arrhythmia (odds ratio [98.3% confidence interval] of 1.07 [0.92, 1.23], p = 0.29). Etomidate was not associated significantly with either intensive care unit or hospital stay. Etomidate was associated significantly with use of packed red blood cells (odds ratio [99.6% confidence interval] of 1.32 [1.02, 1.70], p = 0.002), but not with use of fresh frozen plasma, platelets, or cryoprecipitate. None of the other complications differed significantly between the groups. Conclusions Etomidate was not associated with increased incidence of postoperative atrial arrhythmia or increased intensive care unit or hospital stay.

The head-mounted display (HMD) has the potential to improve the quality of ultrasound-guided procedures. The aim of this non-clinical crossover designed study is to evaluate the feasibility of the HMD for ultrasound-guided nerve block. Eight experienced anesthesiologists performed ultrasound-guided peripheral nerve blocks on a training simulator with a standard approach and with an upside-down approach. Each approach was performed with a control conventional method and with an HMD. The ultrasound image and operating field were recorded by video camera. The procedure time and fractional percentage of time with the needle visible on the ultrasound image were determined. The needle insertion times were 10.4 ± 7.2 s with the control method and 6.8 ± 5.3 s with the HMD method for the standard approach (p = 0.03), and 18.1 ± 10.1 with the control method and 11.8 ± 9.5 s with the HMD method for the upside-down approach (p = 0.002). The fractional percentages of time with the needle visible on the ultrasound image were 34.1 ± 20.9 with the control method and 56.5 ± 13.6% with the HMD method for the standard approach (p < 0.001), and 20.1 ± 13.4 with the control method and 38.2 ± 21.2% with the HMD method for the upside-down approach (p = 0.001). In conclusion, this pilot study using a simulation model indicated that the use of an HMD shortened the procedure time and improved the needle visibility on ultrasound.

Recently several types of head- mounted displays are available for use in the medical field. Because head-mounted display can provide the visualized information without moving direction of eye- sight, ultrasound guided central venous cannulation might be performed more quickly and safer. One of the head-mounted type displays, Near-Eye Display (NED; NED prototype product, JCV Kenwood, Japan) was tested in ultrasound guided central venous cannulation.Eleven experienced anesthesiologists per- formed central venous cannulation on the training sim- ulator with NED and with control method (without NED). Ultrasound real time image and operating field were recorded by video camera and analyzed to iden- tify procedure time, success rate and incidence of unintentional posterior venous wall penetration.With NED, although time required for cen- tral venous cannulation was similar to the time with standard method (31.3 ± 8.7 sec with control and 30.2 ±7.9 sec with NED, P=0.61), unintentional posterior wall penetration tended to occur less frequently (21% with control and 9% with NED, P=0.17).As NED can help practitioners to have both insertion field and ultra- sound image visible without moving eyesight, NED might be a promising assist device for the ultrasound guided central venous cannulation.

International audience; TeO2-based glasses have been attractive because of their high refractive index and third-order nonlinear optical properties. In general, long melting time is required to obtain the homogeneous glass, but it also leads to enhanced interaction between the crucible and the glass melt. In this study, 20Ag2O–80TeO2 nonlinear optical glasses were fabricated by a melt-quenching method using an alumina or platinum crucible for various melting times. And their thermal characteristics, final glass-compositions, glass structures and linear/nonlinear optical properties were evaluated in order to investigate the influences of the incorporation of Al2O3 in 20Ag2O–80TeO2 glass on third-order nonlinear optical susceptibilities.

Preventing pressure ulcers is important in patients undergoing procedures in the park-bench position. We hypothesized that the microclimate around the skin is a significant risk factor for developing pressure ulcers. This research continuously assessed factors of the microclimate in terms of skin temperature and perspiration as well as the interface pressure in order to determine whether the microclimate is an independent risk factor for the development of park-bench position-related pressure ulcers (PBP-PUs). A prospective observational study was conducted among patients undergoing elective surgery in the park-bench position at a general hospital in the metropolitan area of Japan between April and November 2014. Factors of the microclimate, including skin temperature and perspiration, in addition to the interface pressure were continuously measured throughout surgery. Twenty-nine patients were analyzed (mean age 44.4 ± 13.2 years, male 44.8%). Of these 29 patients, seven (24.1%) developed Category I PBP-PUs. The change in skin temperature from baseline to the end of surgery (2.7 ± 0.3 °C vs. 1.9 ± 0.8 °C) and the average peak pressure (119.1 ± 36.8 mmHg vs. 94.5 ± 23.1 mmHg) were significantly higher in the patients with PBP-PUs than in those without PBP-PUs. There were no significant differences in the amount of perspiration between the two groups. A hierarchical logistic regression analysis showed that the change in skin temperature was significantly related to the development of PBP-PUs (unit = 0.1 °C: odds ratio 1.44, 95% confidential interval 1.09-2.33) when adjusted for the average peak pressure and length of surgery. Our results suggest that a change in skin temperature toward a higher value is an independent risk factor for the development of PBP-PUs. Proper intraoperative management of skin temperature may therefore be a promising candidate as a preventive method against PBP-PU development.

BACKGROUND We tested the hypothesis that hypothyroidism, as defined by thyroid-stimulating hormone (TSH) concentration, is associated with a severity-weighted composite of mortality and major cardiovascular and infectious complications after noncardiac surgery. METHODS In this retrospective cohort study, we evaluated adults at the Cleveland Clinic Main Campus between 2005 and 2012, who had had available TSH concentrations within the 6 months before noncardiac surgery. Patients were categorized as (1) hypothyroid (patients who had diagnosis of hypothyroidism any time prior to surgery and increased TSH value (> 5.5 mIU/L) within 6 months prior to surgery); (2) treated (hypothyroid diagnosis and normal TSH concentrations [0.4-5.5 mIU/L]); and (3) euthyroid (no hypothyroid diagnosis and normal TSH concentrations). We conducted pairwise comparisons among the 3 groups using inverse propensity score weighting to control for observed confounding variables. Average relative effect generalized estimating equation model was used for the primary outcome composite of in-hospital cardiovascular morbidity, surgical wound complication or infection, and mortality. Logistic regression and Cox proportional hazards regression were used for secondary outcomes of intraoperative vasopressor use and duration of hospitalization, respectively. RESULTS We identified 800 hypothyroid patients (median TSH: 8.6 mIU/L [Q1, Q3: 6.5, 13.0]), 1805 treated patients (2.0 mIU/L [1.1, 3.2]), and 5612 euthyroid patients (1.7 mIU/L [1.1, 2.6]). There were no significant differences among the hypothyroid, treated, and euthyroid patients on the primary composite outcome (all P values ≥0.30). Hypothyroid patients were slightly more likely to receive vasopressor during surgery than either treated (odds ratio, 1.17; 99.2% confidence interval [CI], 1.01-1.36) or euthyroid (odds ratio, 1.12; 99.2% CI, 1.02-1.24) patients. Furthermore, hypothyroid patients were slightly but significantly less likely to be discharged at any given postoperative time than treated patients (hazard ratio, 0.92; 99.2% CI, 0.86-0.99). CONCLUSIONS Hypothyroidism was not associated with worse postoperative mortality, wound, or cardiovascular outcomes in noncardiac patients. Thus, postponing surgery to initiate thyroid replacement therapy in patients with hypothyroidism seems unnecessary.

Background Goreisan, a traditional Japanese Kampo medicine, may prevent postoperative nausea and vomiting (PONV). The purpose of this study was to evaluate the effect of Goreisan on PONV in a high-risk population in a randomized, double-blind, placebo-controlled manner. Findings Patients undergoing gynecological surgery were randomly allocated to the Goreisan and the control groups. General anesthesia was induced with propofol and remifentanil. After endotracheal intubation, anesthesia was maintained with sevoflurane, fentanyl, and remifentanil. Goreisan 7.5 g dissolved in water (Goreisan group) or water (control group) in a volume of 20 ml was administered through a nasogastric tube approximately 1 h before completion of surgery. The primary outcome of this study was the incidence of PONV during the first 2 h after extubation. In the interim analysis, it was apparent that Goreisan has no effect. Therefore, we discontinued recruiting patients and present results based on data from 83 patients. The incidence of PONV during the first 2 h after extubation was 45% in the Goreisan group (n = 40) and 46.5% in the control group (n = 43) (p = 0.89). There was no significant difference in PONV incidence or severity during the first 24 h post-extubation. Conclusion Goreisan has little potency in preventing PONV in high-risk patients.

Background We tested the primary hypothesis that corticosteroid administration after etomidate exposure reduces a composite of in-hospital mortality and cardiovascular morbidity after non-cardiac surgery. Methods We evaluated ASA physical status III and IV patients who had non-cardiac surgery with general anaesthesia at the Cleveland Clinic. Amongst 4275 patients in whom anaesthesia was induced with etomidate, 804 were also given steroid intraoperatively, mostly dexamethasone at a median dose of 6 mg. We successfully matched 582 steroid patients with 1023 non-steroid patients. The matched groups were compared on composite of in-hospital mortality and cardiovascular morbidity using a generalized-estimating-equation model. Secondly, the matched groups were compared on length of hospital stay using a Cox proportional hazard model, and were descriptively compared on intraoperative blood pressures using a standardized difference. Results There was no significant association between intraoperative steroid administration after anaesthetic induction with etomidate and the composite of in-hospital mortality or cardiovascular morbidity; the estimated common odds ratio across the two components of the composite was 0.86 [95% confidence interval (CI): 0.64, 1.16] for steroid vs non-steroid, P=0.33. The duration of postoperative hospitalisation was significantly shorter amongst steroid patients [median (Q1, Q3): 6 (3, 10) days] than non-steroid patients [7 (4, 11) days], with an estimated hazard ratio of 0.89 (0.80, 0.98) for steroid vs non-steroid, P=0.01. Intraoperative blood pressures were similar in steroid and non-steroid patients. Conclusions Steroid administration after induction of anaesthesia with etomidate did not reduce mortality or cardiovascular morbidity.

This note shows that in the matching-with contracts model, the outcome of the cumulative offer process is order-independent if every hospital has a choice function that satisfies the bilateral substitutability condition and the irrelevance of rejected contracts condition.

A family of TeO2-based glasses is known to have high third-order nonlinear properties and expected as nonlinear optical devices. In the present study, we fabricated Ag2O-TeO2 and Ag2O-Nb2O5-TeO2 glasses, and estimated their structures and linear/nonlinear optical properties. The main results showed that the absorption-edge of the glasses was shifted to longer wavelength side with increasing Ag2O content. By Raman spectroscopy, it was found that an increase in Ag2O content promoted to change TeO4 to TeO3/TeO3+1 units. X-ray photoelectron spectroscopy (XPS) revealed the presence of an electronic state of Ag2+ ions, which was supposed to have a large influence on the absorption-edge wavelength. In Ag2O-Nb2O5-TeO2 glass system, the third-order nonlinear susceptibility χ(3) increased with increasing Ag2O content at the expense of Nb2O5 content.

Summary Background Many anesthetics reduce lower esophageal sphincter pressure (LESP) and consequently the gastro-esophageal pressure gradient (GEPG); thus they may promote gastro-esophageal reflux and contribute to aspiration pneumonia. Our goals were to evaluate the association between LESP and 2 measures of sedation: bispectral index (BIS) and the responsiveness component of the Observer’s Assessment of Alertness score (OAA/S). Material/Methods Eleven healthy volunteers were each sedated on 2 separate days. Subjects were given sedative infusions of increasing target plasma concentrations of dexmedetomidine or propofol. LESP and GEPG were recorded after starting each infusion phase. Generalized estimating equation modeling was used to assess the relationship between LESP and, respectively, BIS and OAA/S. The existence of a drug-dependent association was evaluated within these models by testing an interaction term. Wald tests were used to evaluate the relationships within the models. Results We found a significant relationship between LESP and BIS (P=0.0043) after adjusting for the main effect of sedative type – a deepening of sedation as measured by a decrease in BIS of 10% was associated with a decrease [Bonferroni-adjusted 95% CI] in LESP of −1.34 [−2.39, −0.29] mmHg. After adjusting for the main effect of sedative drug, LESP significantly declined with declining OAA/S (P=0.001); a unit decrease of OAA/S was associated with a decrease [Bonferroni-adjusted 95% CI] in LESP of −2.01 [−3.20, −0.81] mmHg. Conclusions Deeper sedation, as measured by either BIS or OAA/S, significantly reduces LESP.

Purpose Our main objective was to assess incidence, risk factors, and outcomes of ventilator-associated pneumonia (VAP) in stroke patients. Materials and Methods After obtaining approval from the Human Studies Committee, we reviewed the electronic records from our intensive care unit database of 111 stroke patients on mechanical ventilation for more than 48 hours. Thirty-six risk factors related to disease and general health status, and 8 related to care—all assigned a priori—were collected and analyzed. Selected factors with univariate statistical significance (P Results Thirty-one patients developed pneumonia (28%). Methicillin-resistant Staphylococcus aureus (n = 12) and methicillin-sensitive S aureus (n = 7) were the most common pathogenic bacteria. Chronic lung disease, neurological status at admission as assessed by the National Institutes of Health Stroke Scale, and hemorrhagic transformation were the independent risk factors contributing to VAP. Worsening oxygenation index (arterial partial pressure of oxygen/fraction of inspired oxygen) and proton pump inhibitor use for ulcer prophylaxis were other potentially important factors. Conclusions Pneumonia appears as a frequent problem in mechanically ventilated stroke patients. Chronic lung disease history, severity of stroke level at admission, and hemorrhagic transformation of stroke set the stage for developing VAP. The duration of both mechanical ventilation and intensive care unit stay gets significantly prolonged by VAP, but it does not affect mortality.

Tracheal intubation in the lateral position is difficult because the laryngeal view is compromised during direct laryngoscopy. The Airway Scope facilitates intubation even when laryngeal views are poor with direct laryngoscopy, as they often are in the lateral position. We thus compared the efficacy of the Airway Scope in supine patients with those in the left- and right-lateral positions.Anesthetized adults were randomly assigned to supine, left-lateral, or right-lateral position (n = 43 for each group). Laryngeal views were obtained in the designated position with a Macintosh laryngoscope, and patients' tracheas were subsequently intubated with the Airway Scope. Specifically, we tested the hypothesis that the time required for intubation in the left- and right-lateral positions is not increased by10 seconds compared with tracheal intubation in the supine position.Overall intubation success was 100% in the 2 lateral positions, and 98% in the supine position. Intubation times were similar in the left-lateral (24 [5] seconds, mean [SD]), right-lateral (24 [6] seconds), and supine (22 [7] seconds) positions. The numbers of required intubation attempts were similar in the 2 lateral positions and in the supine and left-lateral positions. However, more intubation attempts were required in the supine position than in the right-lateral position (P = 0.004). The incidences of airway complications were similar in each position; no hypoxia, dental injury, or esophageal intubation was observed. Modified Cormack-Lehane and the percentage of glottic opening scores obtained with the Macintosh laryngoscope did not differ between the 2 lateral positions, but the modified Cormack-Lehane and percentage of glottic opening scores were superior in the supine position (all P0.001) compared with either of the lateral positions.Despite worse laryngoscopic views in either lateral position than when patients were supine, intubation with the Airway Scope offered high success rates. Furthermore, intubation time using the Airway Scope in either lateral position was not longer by10 seconds than in the supine position. The Airway Scope thus seems to be a useful tool when tracheal intubation is required in a laterally positioned patient.

Background In this study, the authors determined the success and failure rates for interns learning bag-and-mask ventilation and orotracheal intubation. Their goal was to determine the amount of experience needed to perform these procedures correctly. Methods The authors recorded 695 bag-and-mask ventilations and 679 orotracheal intubations performed by 15 inexperienced interns during their 3 month-long anesthesia rotations. Learning curves for each procedure for each intern were constructed with both the standard and risk-adjusted cumulative sum methods. The average number of procedures required to attain a failure rate of 20% was estimated for each technique. Results Fourteen of 15 interns attained acceptable failure rates at bag-and-mask ventilation after 27 +/- 13 procedures, with a median (95% confidence interval) of 25 (15-32) procedures to cross the decision limit when considering all 15 interns. Nine of 15 interns attained acceptable failure rates at orotracheal intubation after 26 +/- 8 procedures, with a median of 29 (22-not estimable) procedures to cross the limit when considering all interns. The proportion of interns who attained acceptable failure rates for mask ventilation was greater than for tracheal intubation (93% vs. 60%, P = 0.025). Overall, our interns achieved a bag-and-mask ventilation failure rate of 20% or better after a median of 25 procedures; approximately 80% of interns achieved the goal after 35 procedures or less. Conclusions Participating interns developed mask ventilation skills faster than orotracheal intubation skills, and there was more variability in the rate at which intubation skills developed. A median of 29 procedures was required to achieve an 80% orotracheal intubation success rate.

Adenosine is a soporific neuromodulator; aminophylline, which is clinically used as a bronchodilator, antagonizes the action of adenosine in the central nervous system. Thus, we tested the hypothesis that aminophylline delays loss of consciousness (LOC) and speeds recovery of consciousness (ROC) with propofol anesthesia, and that aminophylline increases the minimum alveolar concentration (MAC) of desflurane.In this double-blind crossover study, volunteers were randomized to either aminophylline or saline on different days. Aminophylline 6 mg/kg was given IV, followed by 1.5 mg x kg(-1) x h(-1) throughout the study day. After 1 h of aminophylline or saline administration, propofol 200 mg was given at a rate of 20 mg/min. The bispectral index was continuously monitored, as were times to LOC and ROC. After recovery from propofol, general anesthesia was induced with sevoflurane and subsequently maintained with desflurane. The Dixon "up-and-down" method was used to determine MAC in each volunteer after repeated tetanic electrical stimulation.Eight volunteers completed both study days. Time to LOC was prolonged by aminophylline compared with saline (mean +/- SD) (7.7 +/- 2.03 min vs 5.1 +/- 0.75 s, respectively, P = 0.011). The total propofol dose at LOC was larger with aminophylline (2.2 +/- 0.9 vs 1.4 +/- 0.4 mg/kg, P = 0.01), and the time to ROC was shorter (6.18 +/- 3.96 vs 12.2 +/- 4.73 min, P = 0.035). The minimum bispectral index was greater with aminophylline (51 +/- 15 vs 38 +/- 9, P = 0.034). There was no difference in MAC.Aminophylline decreases the sedative effects of propofol but does not affect MAC of desflurane as determined by tetanic electrical stimulation.

Bispectral index (BIS) is a widely used quantitative parameter for evaluating anesthesia and sedation levels. Dexmedetomidine is a novel sedative, providing sedation while patients remain cooperative and can be easily aroused; as a consequence, BIS used with dexmedetomidine may poorly characterize sedation. Thus, we tested the hypothesis that BIS values are lower with dexmedetomidine than with propofol at comparable Observer's Assessment of Alertness and Sedation (OAA/S) scores.This was a randomized, 2-day, crossover study. On the first study day, healthy volunteers were randomly allocated to either propofol or dexmedetomidine sedation. Drugs were administered using computer-controlled infusions targeting an effect-site concentration of 1, 2, and 4 microg/mL for propofol or a plasma concentration of 0.6, 1.2, and 2.4 ng/mL for dexmedetomidine. The relationship between BIS and OAA/S score was obtained 20 and 40 min after changing each drug concentration. BIS values at each OAA/S score were compared between drugs. The cutoff values of BIS for OAA/S score ofor =2 were obtained by analysis of receiver operating characteristic curves.Nine volunteers were included in our analysis. Heart rates decreased significantly with dexmedetomidine sedation. ETco(2) was significantly increased with high doses of propofol but did not increase with high doses of dexmedetomidine. BIS values at OAA/S scores of 1, 2, 3, 4, and 5 during propofol sedation were 95.5 (90-97), 78 (71-84.5), 67 (64-70), 57 (51.5-60), and 34 (30-37), respectively. BIS values at OAA/S scores of 1, 2, 3, 4, and 5 during dexmedetomidine sedation were 95 (79-98), 62 (53.5-68.5), 45.5 (45.3-52), 39.5 (34.3-41.8), and 24.5 (22.5-30.5), respectively. BIS values were significantly less with dexmedetomidine than propofol at OAA/S responsiveness scores of 2, 3, and 4. The calculated cutoff BIS values for OAA/S scores ofor =2 were 67 (sensitivity of 86%, specificity of 97%, and area under the curve of 0.98) for propofol and 46 (sensitivity of 84%, specificity of 91%, and area under the curve of 0.96) for dexmedetomidine.The combination of both BIS and sedative scales could provide different and complementary data to the clinician evaluating the patient's response to sedation than would either tool alone, especially when dexmedetomidine is used.

Background Hypothermia may be beneficial in stroke victims; however, it provokes vigorous shivering. Buspirone and dexmedetomidine each linearly reduce the shivering threshold with minimal sedation and no respiratory depression. This study tested the hypotheses that the combination of buspirone and dexmedetomidine would (1) synergistically reduce the shivering threshold, (2) synergistically reduce the gain and maximum intensity of shivering, and (3) produce sufficient inhibition to permit cooling to 34 degrees C without excessive hypotension or sedation. Methods Eight healthy men were randomly assigned on 4 days to (1) no drug, (2) buspirone (60 mg orally), (3) dexmedetomidine (intravenous infusion to target plasma concentration of 0.6 ng/ml), or (4) combination of buspirone and dexmedetomidine at same doses. Lactated Ringer's solution (approximately 3 degrees C) was infused intravenously to decrease tympanic membrane temperature by 1.5 degrees C/h. Shivering threshold was defined as an increase in oxygen consumption greater than 20%. Sedation was evaluated using the Observer's Assessment of Sedation/Alertness scale. Results Mean arterial pressure and heart rate were slightly lower on dexmedetomidine and combination days. Likewise, the level of sedation was statistically different on these 2 days but clinically unimportant. Buspirone reduced the shivering threshold from 36.6 degrees C +/- 0.4 degrees C to 35.9 degrees C +/- 0.4 degrees C, dexmedetomidine reduced it to 34.7 degrees C +/- 0.5 degrees C, and the combination to 34.1 +/- 0.4 degrees C. The interaction effect of 0.04 degrees C was not significant. The gain of shivering and maximum shivering intensity were similar on each day. Conclusions The combination of buspirone and dexmedetomidine additively reduced the shivering threshold. Thus, supplementing dexmedetomidine with buspirone blocks shivering and causes only minimal sedation.

From April 2013, Macintosh direct laryngoscopes (DL) were replaced by McGRATH® MAC video laryngoscopes (VL), and VL were distributed in all of our operating rooms and used as routine first choice devices. Purpose of this study was to compare the success rate of the first attempt tracheal intubation by the trainees with VL and DL. Incidence of tracheal intubation related injuries were also assessed.We reviewed anesthesia chart database in which tracheal intubations were provided by anesthesia trainees with experience of less than 3 months. Patient demographics, Mallampati classification and tracheal intubation profiles including type of the tracheal tube and devices were recorded.The first attempt success rate was 78.6% with DL and 92.8% with VL (P0.001). More than 2 repeated trial incidence was 5.2% with DL and 1.3% with VL (P0.001). Incidence of mucosal injury was lower with DL than VL.VL notably improved the first success rate of tracheal intubation compared with DL among trainees.

This note provides three additional results that are omitted from Hirata and Kasuya (2017) but were contained in an older version (Hirata and Kasuya, 2015).

In order to build intelligent spaces based on many distributed sensors, it is necessary to know where the distributed sensors are placed in the spaces. We have proposed a system for supporting sensor position estimation to build large-scale intelligent spaces easily. The system is based on sharing global maps and positions of a mobile robot with distributed sensors. In this paper, the software modules based on RT-components with dynamic port connections among the robot and distributed sensors are introduced. Then, the online position estimation system of distributed sensors without restriction of sensor placement is achieved and a demonstration of building an intelligent space is shown.

Preventing pressure ulcers is important in patients undergoing procedures in the park-bench position. We hypothesized that the microclimate around the skin is a significant risk factor for developing pressure ulcers. This research continuously assessed factors of the microclimate in terms of skin temperature and perspiration as well as the interface pressure in order to determine whether the microclimate is an independent risk factor for the development of park-bench position-related pressure ulcers (PBP-PUs). A prospective observational study was conducted among patients undergoing elective surgery in the park-bench position at a general hospital in the metropolitan area of Japan between April and November 2014. Factors of the microclimate, including skin temperature and perspiration, in addition to the interface pressure were continuously measured throughout surgery. Twenty-nine patients were analyzed (mean age 44.4 ± 13.2 years, male 44.8%). Of these 29 patients, seven (24.1%) developed Category I PBP-PUs. The change in skin temperature from baseline to the end of surgery (2.7 ± 0.3 °C vs. 1.9 ± 0.8 °C) and the average peak pressure (119.1 ± 36.8 mmHg vs. 94.5 ± 23.1 mmHg) were significantly higher in the patients with PBP-PUs than in those without PBP-PUs. There were no significant differences in the amount of perspiration between the two groups. A hierarchical logistic regression analysis showed that the change in skin temperature was significantly related to the development of PBP-PUs (unit = 0.1 °C: odds ratio 1.44, 95% confidential interval 1.09-2.33) when adjusted for the average peak pressure and length of surgery. Our results suggest that a change in skin temperature toward a higher value is an independent risk factor for the development of PBP-PUs. Proper intraoperative management of skin temperature may therefore be a promising candidate as a preventive method against PBP-PU development.

Background Tissue oxygenation is a strong predictor of surgical site infection. Improving tissue oxygenation should thus reduce wound infection risk. Supplemental inspired oxygen can improve tissue oxygenation, but whether it reduces infection risk remains controversial. Low-dose dexamethasone is often given to reduce the risk of postoperative nausea and vomiting, but steroid-induced immunosuppression can increase infection risk. We therefore tested the hypotheses that supplemental perioperative oxygen reduces infection risk and that dexamethasone increases it. Methods Using a factorial design, patients having colorectal resections expected to last ≥2 h were randomly assigned to 30% (n=270) or 80% (n=285) inspired oxygen during and for 1 h after surgery, and to 4 mg intraoperative dexamethasone (n=283) or placebo (n=272). Physicians blinded to group assignments evaluated wounds postoperatively, using US Centers for Disease Control criteria. Results Subject and surgical characteristics were similar among study groups. Surgical site infection incidence was similar among groups: 30% oxygen 15.6%, 80% oxygen 15.8% (P=1.00); dexamethasone 15.9%, placebo 15.4%, (P=0.91). Conclusions Supplemental oxygen did not reduce surgical site infection risk. The preponderance of clinical evidence suggests that administration of 80% supplemental inspired oxygen does not reduce infection risk. We did not observe an increased risk of surgical site infection with the use of a single low dose of dexamethasone, indicating that it can be used for nausea and vomiting prophylaxis without promoting wound infections. Clinical trial registration ClinicalTrials.gov number: NCT00273377.

Single crystals of lead magnesium niobate–lead titanate, Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT), have superior dielectric and piezoelectric properties suitable for medical ultrasound imaging. Imaging devices with superior performance can be manufactured from thinner PMN–PT single crystals by mechanical dicing and/or polishing. Although it is often a concern that a damaged layer may form during the mechanical dicing and/or thinning process, the microscopic characteristics of the damaged layer have not yet been investigated in detail. In this study, the microstructural characterization of a damaged layer was investigated by transmission electron microscopy. It was found that mechanical polishing introduced dislocation near the surface of the crystal. It was also found that the domain structure was affected by the introduction of dislocation.

In this study, the authors determined the success and failure rates for interns learning bag-and-mask ventilation and orotracheal intubation. Their goal was to determine the amount of experience needed to perform these procedures correctly.The authors recorded 695 bag-and-mask ventilations and 679 orotracheal intubations performed by 15 inexperienced interns during their 3 month-long anesthesia rotations. Learning curves for each procedure for each intern were constructed with both the standard and risk-adjusted cumulative sum methods. The average number of procedures required to attain a failure rate of 20% was estimated for each technique.Fourteen of 15 interns attained acceptable failure rates at bag-and-mask ventilation after 27 +/- 13 procedures, with a median (95% confidence interval) of 25 (15-32) procedures to cross the decision limit when considering all 15 interns. Nine of 15 interns attained acceptable failure rates at orotracheal intubation after 26 +/- 8 procedures, with a median of 29 (22-not estimable) procedures to cross the limit when considering all interns. The proportion of interns who attained acceptable failure rates for mask ventilation was greater than for tracheal intubation (93% vs. 60%, P = 0.025). Overall, our interns achieved a bag-and-mask ventilation failure rate of 20% or better after a median of 25 procedures; approximately 80% of interns achieved the goal after 35 procedures or less.Participating interns developed mask ventilation skills faster than orotracheal intubation skills, and there was more variability in the rate at which intubation skills developed. A median of 29 procedures was required to achieve an 80% orotracheal intubation success rate.

Background Obtaining accurate end-tidal carbon dioxide pressure measurements via nasal cannula poses difficulties in postanesthesia patients who are mouth breathers, including those who are obese and those with obstructive sleep apnea (OSA); a nasal cannula with an oral guide may improve measurement accuracy in these patients. The authors evaluated the accuracy of a mainstream capnometer with an oral guide nasal cannula and a sidestream capnometer with a nasal cannula that did or did not incorporate an oral guide in spontaneously breathing non-obese patients and obese patients with and without OSA during recovery from general anesthesia. Methods The study enrolled 20 non-obese patients (body mass index less than 30 kg/m) without OSA, 20 obese patients (body mass index greater than 35 kg/m) without OSA, and 20 obese patients with OSA. End-tidal carbon dioxide pressure was measured by using three capnometer/cannula combinations (oxygen at 4 l/min): (1) a mainstream capnometer with oral guide nasal cannula, (2) a sidestream capnometer with a nasal cannula that included an oral guide, and (3) a sidestream capnometer with a standard nasal cannula. Arterial carbon dioxide partial pressure was determined simultaneously. The major outcome was the arterial-to-end-tidal partial pressure difference with each combination. Results In non-obese patients, arterial-to-end-tidal pressure difference was 3.0 +/- 2.6 (mean +/- SD) mmHg with the mainstream capnometer, 4.9 +/- 2.3 mmHg with the sidestream capnometer and oral guide cannula, and 7.1 +/- 3.5 mmHg with the sidestream capnometer and a standard cannula (P < 0.05). In obese non-OSA patients, it was 3.9 +/- 2.6 mmHg, 6.4 +/- 3.1 mmHg, and 8.1 +/- 5.0 mmHg, respectively (P < 0.05). In obese OSA patients, it was 4.0 +/- 3.1 mmHg, 6.3 +/- 3.2 mmHg, and 8.3 +/- 4.6 mmHg, respectively (P < 0.05). Conclusions Mainstream capnometry performed best, and an oral guide improved the performance of sidestream capnometry. Accuracy in non-obese and obese patients, with and without OSA, was similar.

A 53-year-old woman developed general fatigue following an upper airway infection, which abruptly progressed to cardiogenic shock showing systolic blood pressure of 60 mmHg. An echocardiography revealed an ejection fraction of 0.11, diffuse severe hypokinesis and left ventricular thrombosis. Fulminant myocarditis was suspected, and intensive care including mechanical ventilation, intraaortic balloon pumping (IABP), catecholamine support and anticoagulation therapy was initiated immediately. Although the cardiac function gradually recovered, she developed a duodenal bleeding on the third therapeutic day. Factors such as low output syndrome, heparinization, steroid pulse therapy and platelet dysfunction due to IABP can enhance the hemorrhagic tendency. Since it was difficult to control bleeding by the endoscopy, blood transfusion was performed, and the operation was planned on the 13rd day when the cardiac function seemed to have recovered enough. The patient was anesthetized with ketamine, propofol and fentanyl. To maintain stable circulation, circulatory parameters such as blood pressure, central venous pressure, and cardiac output were monitored. After a preoperative consultation with the surgeon, the surgical technique had been preoperatively decided to reduce the surgical stress, and then partial duodenosectomy and gastro-jejunum anastomosis was performed. She was discharged on the 38th post operative day without complications. In cases of hemorrhagic disease accompanied by an acute phase of fulminant myocarditis, consultation among surgeons, cardiologists and anesthegiologists should be mandatory to determine the timing of the operation and to decide the degree of surgical invasion.