Search

Purpose: We investigated the impact of surgical masks (SM) during oxygen therapy using oxygen masks in volunteer- and simulation-based studies. Methods: Fifteen volunteers wore the Hudson RCI® or Open-Face Mask® with/without an SM. The fraction of inspired oxygen concentration (FIO2), end-tidal CO2 (EtCO2), partial pressure of inspired CO2 (PICO2), and respiratory rate (RR) were measured. The oxygen flow rate increased from 0 to 10 L/min. In the simulation-based study, FIO2 was measured using a simulator that reproduced spontaneous breathing. RR was 12 or 24 bpm, and the tidal volume (Tv) was 300, 500, or 700 mL. The effect of oxygen mask fitting conditions were also examined. The primary outcome measure was FIO2 at 6 L/min. Results: In the volunteer-based study, FIO2 was reduced when the SM was used with the Hudson RCI® or Open-Face Mask®. The FIO2 drop was larger with the Open-Face Mask® than with the Hudson RCI®. The RR, EtCO2, and PICO2 significantly changed with the SM, but the differences were not clinically meaningful. In the simulation-based study, the SM with the Hudson RCI® did not reduce FIO2, but the SM with the Open-Face Mask® significantly decreased FIO2 under several conditions. However, the SM with the Hudson Mask® reduced FIO2 when the fit of the mask was inadequate. With the Open-Face Mask®, lower RR and Tv resulted in larger differences in FIO2. Conclusions: The SM decreased FIO2 during oxygen therapy with oxygen masks. The impact of SM depended on the type of the oxygen mask, mask fitting, and respiratory condition.

Purpose: Although it is important to recognize gender disparities in publishing to achieve gender diversity, women's authorship in Japan remains unclear. Therefore, this study aimed to investigate the percentage and analyze the trends of articles authored and published in anesthesiology journals by Japanese female authors. Methods: The genders of the first and last authors affiliated with Japanese institutions were surveyed in the Journal of Anesthesia (JA) (1990, 1995, and 2000–2022) and 11 international anesthesiology journals (2010–2022). Results: We included 845 and 819 original research articles from JA in the analyses of the first and last authors, respectively. The proportion of female first authors significantly increased from 41 (11.7%) out of 351 before 2009 to 119 (24.1%) out of 494 after 2010 (p < 0.001). The proportion of female last authors was 11 (3.3%) out of 335 before 2009 and 22 (4.5%) out of 484 after 2010, respectively, with no significant difference (p = 0.470). We included 624 and 572 original research articles from international anesthesiology journals in the analyses of first and last authors, respectively. Among these, there were 134 (21.5%) and 23 (4.0%) female first and last authors, respectively. These proportions in international anesthesiology journals did not significantly differ from those in JA (p = 0.334, p = 0.789, respectively). Conclusion: The percentage of female first authors has increased, commensurate with the percentage of female anesthesiologists. However, the percentage of female last authors has not increased and remains low in Japan.

Background Remimazolam confers a lower risk of hypotension than propofol. However, no studies have compared the efficacy of remimazolam and propofol administered using target-controlled infusion (TCI). This study aimed to investigate hemodynamic effects of remimazolam and target-controlled propofol in middle-aged and elderly patients during the induction of anesthesia. Methods Forty adults aged 45–80 years with the American Society of Anesthesiologists Physical Status 1–2 were randomly assigned to remimazolam or propofol group (n = 20 each). Patients received either remimazolam (12 mg/kg/h) or propofol (3 μg/mL, TCI), along with remifentanil for inducing anesthesia. We recorded the blood pressure, heart rate (HR), and estimated continuous cardiac output (esCCO) using the pulse wave transit time. The primary outcome was the maximum change in mean arterial pressure (MAP) after induction. Secondary outcomes included changes in HR, cardiac output (CO), and stroke volume (SV). Results MAP decreased after induction of anesthesia in both groups, without significant differences between the groups (− 41.1 [16.4] mmHg and − 42.8 [10.8] mmHg in remimazolam and propofol groups, respectively; mean difference: 1.7 [95% confidence interval: − 8.2 to 4.9]; p = 0.613). Furthermore, HR, CO, and SV decreased after induction in both groups, without significant differences between the groups. Remimazolam group had significantly shorter time until loss of consciousness than propofol group (1.7 [0.7] min and 3.5 [1.7] min, respectively; p p = 0.341). Conclusions Hemodynamics were not significantly different between remimazolam and target-controlled propofol groups during induction of anesthesia. Thus, not only the choice but also the dose and usage of anesthetics are important for hemodynamic stability while inducing anesthesia. Clinicians should monitor hypotension while inducing anesthesia with remimazolam as well as propofol. Trial registration UMIN-CTR (UMIN000045612).

Objectives To compare the effects of nicorandil and nitroglycerin on arterial oxygenation during two-lung ventilation (TLV) and one-lung ventilation (OLV) in patients with risk factors for myocardial ischemia. Design A prospective, randomized, double-blind study. Setting A tertiary care hospital. Participants Fifty-six patients scheduled for elective video-assisted thoracic surgery were assigned randomly to either the nicorandil group or the nitroglycerin group. Interventions Patients in the nicorandil group received a bolus dose of nicorandil, 0.08 mg/kg during induction of anesthesia, followed by a continuous infusion at a rate of 0.08 mg/kg/h. Patients in the nitroglycerin group received a continuous infusion of nitroglycerin at a rate of 1 µg/kg/min from the induction of anesthesia. Measurements and Main Results Arterial blood gas analysis was performed at the following points: before induction of anesthesia; during TLV; at 5, 10, 20, and 30 minutes after the initiation of OLV. PaO2 at TLV (479.7 ± 57.1 v 408.2 ± 70.9 mmHg, p Conclusion This study demonstrated that oxygenation during TLV and OLV was significantly higher in patients receiving nicorandil than in those receiving nitroglycerin.

Background It is useful to monitor eye movements during general anesthesia, but few studies have examined neurological finding of the eyes during emergence from general anesthesia maintained with short-acting opioids and volatile anesthetics. Methods Thirty children aged 1–6 years and 30 adults aged 20–79 years were enrolled. Patients received general anesthesia maintained with sevoflurane and remifentanil. The timing of three physical-behavioral responses—eye-gaze transition (the cycle from conjugate to disconjugate and back to conjugate), resumption of somatic movement (limbs or body), and resumption of respiration—were recorded until spontaneous awakening. The primary outcome measure was the timing of the physical-behavioral responses. Secondary outcome measures were the incidence of eye-gaze transition, and the bispectral index, concentration of end-tidal sevoflurane, and heart rate at the timing of eye-gaze transition. Results Eye-gaze transition was evident in 29 children (96.7%; 95% confidence interval, 82.8–99.9). After the end of surgery, eye-gaze transition was observed significantly earlier than resumption of somatic movement or respiration (472 [standard deviation 219] s, 723 [235] s, and 754 [232] s, respectively; p < 0.001). In adults, 3 cases (10%; 95% CI, 0.2–26.5) showed eye-gaze transition during emergence from anesthesia. The incidence of eye-gaze transition was significantly lower in adults than in children (p < 0.001). Conclusion In children, eye-gaze transition was observed significantly earlier than other physical-behavioral responses during emergence from general anesthesia and seemed to reflect emergence from anesthesia. In contrast, observation of eye gaze was not a useful indicator of emergence from anesthesia in adults.

Background Cardiac protection by volatile anesthetic-induced preconditioning and ischemic preconditioning have similar signaling pathways. Recently, it was reported that augmentation of protein modified with O-linked β-N-acetylglucosamine (O-GlcNAc) contributes to cardiac protection. This study investigated the role of O-GlcNAc in cardiac protection induced by anesthetic-induced preconditioning. Methods O-GlcNAc-modified proteins were visualized by immunoblotting. Tolerance against ischemia or reperfusion was tested in vivo (n = 8) and in vitro (n = 6). The opening of the mitochondrial permeability transition pore (mPTP) upon oxidative stress was examined in myocytes treated with calcein AM (n = 5). Coimmunoprecipitation and enzymatic labeling were performed to detect the mitochondrial protein responsible for the mPTP opening. Results Isoflurane treatment and the consequent augmentation of O-GlcNAc concentrations reduced the infarct size (26 ± 5% [mean ± SD], P < 0.001) compared with the control. The protective effect of O-GlcNAc was eliminated in the group pretreated with the O-GlcNAc transferase inhibitor alloxan (39 ± 5%, P < 0.001). Myocyte survival also showed the same result in vitro. Formation of the mPTP was abrogated in the isoflurane-treated cells (86 ± 4%, P < 0.001) compared with the control and alloxan-plus-isoflurane-treated cells (57 ± 7%, P < 0.001). Coimmunoprecipitation and enzymatic labeling studies revealed that the O-GlcNAc-modified, voltage-dependent anion channel restained the mPTP opening. Conclusions Isoflurane induced O-GlcNAc modification of mitochondrial voltage-dependent anion channel. This modification inhibited the opening of the mPTP and conferred resistance to ischemia-reperfusion stress.

ResumoJustificativaInvestigamos os efeitos de um novo método de anestesia, que combina propofol e anestesia volátil, sobre a incidência de náusea e vômito no período pós‐operatório de pacientes submetidas à laparoscopia ginecológica.MétodosAs pacientes foram randomicamente divididas em três grupos: manutenção com sevoflurano (Grupo S, n = 42), com propofol (Grupo P, n = 42) ou com a combinação de propofol e sevoflurano (Grupo PS, n = 42). Avaliamos as respostas completas (sem náusea e vômito no pós‐operatório e sem uso de antiemético de resgate), incidência de náusea e vômito, escore de gravidade da náusea, frequência de vômitos, uso de antiemético de resgate e dor no pós‐operatório em duas e 24horas após a cirurgia.ResultadosO número de doentes que apresentou uma resposta completa foi maior nos grupos P e PS do que no Grupo S em 0‐duashoras (74%, 76% e 43%m respectivamente, p = 0,001) e 0‐24horas (71%, 76% e 38%, respectivamente, p < 0,0005). A incidência de náusea em 0‐duashoras (Grupo S = 57%, Grupo P = 26% e Grupo PS = 21%, p = 0,001) e 0‐24horas (Grupo S = 62%; Grupo P = 29% e grupo PS = 21%, p < 0,0005) também foi significativamente diferente entre os grupos. Porém, não houve diferença significativa entre os grupos em relação à incidência ou frequência de vômitos ou uso de antiemético de resgate em 0‐24horas.ConclusãoA combinação de propofol e anestesia volátil durante a laparoscopia ginecológica efetivamente diminui a incidência de náusea no pós‐operatório.AbstractBackgroundWe investigated the effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery.MethodsPatients were randomly divided into three groups: those maintained with sevoflurane (Group S; n = 42), propofol (Group P; n = 42), or combined propofol and sevoflurane (Group PS; n = 42). We assessed complete response (no postoperative nausea and vomiting and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity score, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24h after surgery.ResultsThe number of patients who exhibited a complete response was greater in Groups P and PS than in Group S at 0‐2h (74%; 76% and 43%; respectively, p = 0.001) and 0‐24h (71%; 76%, and 38%; respectively, p < 0.0005). The incidence of nausea at 0‐2h (Group S = 57%; Group P = 26% and Group PS = 21%; p = 0.001) and 0‐24h (Group S = 62%; Group P = 29% and Group PS = 21%; p < 0.0005) was also significantly different among groups. However, there were no significant differences among groups in the incidence or frequency of vomiting or rescue antiemetic use at 0‐24h.ConclusionCombined propofol and volatile anesthesia during laparoscopic gynecological surgery effectively decreases the incidence of postoperative nausea.

Background Remifentanil enhances intraoperative hemodynamic stability, suggesting that it may decrease intraoperative blood loss when included as an adjuvant to general anesthesia. This retrospective study compared intraoperative blood loss during spinal surgery in patients administered either remifentanil or fentanyl as an opioid adjuvant. Methods We reviewed clinical and surgical data from 64 consecutive laminoplasty or laminectomy patients treated at National Hospital Organization Zentsuji Hospital between April 2010 and March 2011. Patients received either remifentanil (n = 35) or fentanyl (n = 29) as an opioid analgesic during general anesthesia. In addition to intraoperative blood loss, indices of hemodynamic stability, including heart rate as well as systolic, mean, and diastolic blood pressure (BP), were compared over the entire perioperative period between remifentanil and fentanyl groups. Results The remifentanil group exhibited significantly lower intraoperative arterial BP than the fentanyl group. Intraoperative blood loss was also significantly lower in the remifentanil group (125 ± 67 mL vs. 165 ± 82 mL, P = 0.035). Conclusions Intraoperative blood loss during spinal surgery was decreased in patients who received remifentanil as an opioid adjuvant, possibly because of lower intraoperative BP. A larger-scale prospective randomized controlled trial is warranted to confirm our results and to test whether remifentanil can decrease intraoperative blood loss during other surgical procedures.