Myeloid cell-derived reactive oxygen species externally regulate the proliferation of myeloid progenitors in emergency granulopoiesis.

The cellular mechanisms controlling infection-induced emergency granulopoiesis are poorly defined. Here we found that reactive oxygen species (ROS) concentrations in the bone marrow (BM) were elevated during acute infection in a phagocytic NADPH oxidase-dependent manner in myeloid cells. Gr1(+) myeloid cells were uniformly distributed in the BM, and all c-kit(+) progenitor cells were adjacent to Gr1(+) myeloid cells. Inflammation-induced ROS production in the BM played a critical role in myeloid progenitor expansion during emergency granulopoiesis. ROS elicited oxidation and deactivation of phosphatase and tensin homolog (PTEN), resulting in upregulation of PtdIns(3,4,5)P3 signaling in BM myeloid progenitors. We further revealed that BM myeloid cell-produced ROS stimulated proliferation of myeloid progenitors via a paracrine mechanism. Taken together, our results establish that phagocytic NADPH oxidase-mediated ROS production by BM myeloid cells plays a critical role in mediating emergency granulopoiesis during acute infection.

Diesel exhaust particle exposure exacerbates ciliary and epithelial barrier dysfunction in the multiciliated bronchial epithelium models.

Airway epithelium, the first defense barrier of the respiratory system, facilitates mucociliary clearance against inflammatory stimuli, such as pathogens and particulates inhaled into the airway and lung. Inhaled particulate matter 2.5 (PM2.5) can penetrate the alveolar region of the lung, and it can develop and exacerbate respiratory diseases. Although the pathophysiological effects of PM2.5 in the respiratory system are well known, its impact on mucociliary clearance of airway epithelium has yet to be clearly defined. In this study, we used two different 3D in vitro airway models, namely the EpiAirway-full-thickness (FT) model and a normal human bronchial epithelial cell (NHBE)-based air-liquid interface (ALI) system, to investigate the effect of diesel exhaust particles (DEPs) belonging to PM2.5 on mucociliary clearance. RNA-sequencing (RNA-Seq) analyses of EpiAirway-FT exposed to DEPs indicated that DEP-induced differentially expressed genes (DEGs) are related to ciliary and microtubule function and inflammatory-related pathways. The exposure to DEPs significantly decreased the number of ciliated cells and shortened ciliary length. It reduced the expression of cilium-related genes such as acetylated α-tubulin, ARL13B, DNAH5, and DNAL1 in the NHBEs cultured in the ALI system. Furthermore, DEPs significantly increased the expression of MUC5AC, whereas they decreased the expression of epithelial junction proteins, namely, ZO1, Occludin, and E-cadherin. Impairment of mucociliary clearance by DEPs significantly improved the release of epithelial-derived inflammatory and fibrotic mediators such as IL-1ß, IL-6, IL-8, GM-CSF, MMP-1, VEGF, and S100A9. Taken together, it can be speculated that DEPs can cause ciliary dysfunction, hyperplasia of goblet cells, and the disruption of the epithelial barrier, resulting in the hyperproduction of lung injury mediators. Our data strongly suggest that PM2.5 exposure is directly associated with ciliary and epithelial barrier dysfunction and may exacerbate lung injury.

Impact of Remimazolam versus Sevoflurane Anesthesia on Cerebral Oxygenation and Intracranial Pressure during Gynecological Laparoscopy with Mild Hypercapnia.

BACKGROUND Remimazolam has the advantage of better hemodynamic stability compared with other anesthetics. We compared the effects of remimazolam and sevoflurane on cerebral oxygenation, intracranial pressure, and intraoperative hemodynamic parameters during mild hypercapnia in patients undergoing laparoscopy in the Trendelenburg position. MATERIAL AND METHODS Sixty-two patients (20-65 years old) scheduled for gynecological laparoscopy were randomly allocated to either the remimazolam (n=31) or sevoflurane (n=31) group. Respiratory and hemodynamic parameters and regional cerebral oxygen saturation (rSO2) were recorded. Intracranial pressure was measured using the optic nerve sheath diameter (ONSD). RESULTS The change over time in rSO2 did not differ between groups (P=0.056). The change in ONSD over time showed a significant intergroup difference (P=0.002). ONSD significantly changed over time (P=0.034) in the sevoflurane group but not in the remimazolam group (P=0.115). The changes in mean arterial pressure and heart rate over time showed significant intergroup differences (P=0.045 and 0.031, respectively). The length of stay and the use of rescue antiemetics and analgesics in the postanesthetic care unit were significantly lower in the remimazolam group than in the sevoflurane group (P=0.023, 0.038, and 0.018, respectively). CONCLUSIONS Remimazolam can provide a favorable hemodynamic profile and attenuate the increase in ONSD during gynecological laparoscopy compared with sevoflurane anesthesia during lung-protective ventilation with mild hypercapnia. Remimazolam can provide faster and better postoperative recovery than sevoflurane anesthesia.

Ellagic acid induces beige remodeling of white adipose tissue by controlling mitochondrial dynamics and SIRT3.

To determine whether ellagic acid (EA) induces the "beige remodeling" of white adipose tissue (WAT), we treated cold-exposed mice and mouse stromal vascular fraction (SVF) cells with EA, a phytochemical abundant in fruits and vegetables, in particular berries. We then investigated the mechanism of EA in beige remodeling with a particular focus on DRP1-mediated mitochondrial fission and SIRT3. EA induced the trans-differentiation of white adipocytes to beige adipocytes by promoting the expression of UCP1 and other brown and beige adipocytes/fat factors (PRDM16, UCP1, PGC1α, CD137, and TBX1) and mitochondrial dynamics-related factors (SIRT3, NRF1, CPT1ß, DRP1, and FIS1) in 3T3-L1/SVF cells, and these were confirmed in the inguinal WAT of a cold-exposed mouse model. The browning effect of EA was abolished by a potent DRP1 inhibitor Mdivi-1 or SIRT3 knockdown, suggesting that EA induces beige remodeling of WAT by regulating the mitochondrial dynamics and SIRT3.

Farnesol induces mitochondrial/peroxisomal biogenesis and thermogenesis by enhancing the AMPK signaling pathway in vivo and in vitro.

Thermogenic activation of brown adipose tissue has been considered as an obesity treatment strategy that consumes energy. In this study, we investigated whether farnesol in vivoandin vitro models induces thermogenesis and affect the activation of the mitochondria and peroxisomes, which are key organelles in activated brown adipocytes. Farnesol induced the expression of thermogenic factors such as uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor γ coactivator 1 alpha (PGC1α), and PR domain zinc-finger protein 16 (PRDM16) together with the phosphorylation of AMP-activated protein kinase alpha (AMPKα) in brown adipose tissue and primary cultured brown adipocytes. Farnesol promoted lipolytic enzymes: hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). We confirmed that these inductions of lipolysis by farnesol were the underlying causes of ß-oxidation activation. Farnesol also increased the expression of oxidative phosphorylation (OXPHOS) complexes and the oxygen consumption rate (OCR) and the expansion of peroxisomes. Moreover, we proved that the thermogenic activity of farnesol was dependent on AMPKα activation using Compound C inhibitor or siRNA-AMPKα knockdown. These results suggest that farnesol may be a potential agent for the treatment of obesity by inducing energy consumption through heat generation.

Comparison of remifentanil concentrations with and without dexmedetomidine for the prevention of emergence cough after nasal surgery: a randomized double-blinded trial.

BACKGROUND: Preventing emergence cough after nasal surgery is critical. Emergence cough can provoke immediate postoperative bleeding, which leads to upper airway obstruction. In the present study, we compared the effect-site concentration (Ce) of remifentanil to prevent emergence cough after propofol anesthesia for nasal surgery when remifentanil was or was not combined with dexmedetomidine. METHODS: Forty-seven patients with propofol-remifentanil anesthesia for nasal surgery were randomly assigned to a dexmedetomidine group (Group D, n = 23) or a saline group (Group S, n = 24). Group D and Group S were infused with dexmedetomidine (0.5 µg/kg) and saline, respectively, for 10 min before the completion of surgery. A predetermined Ce of remifentanil was infused until extubation. Remifentanil Ce to prevent cough in 50 and 95% of patients (EC50 and EC95) was estimated using modified Dixon's up-and-down method and isotonic regression. Hemodynamic and recovery parameters were recorded. RESULTS: The EC50 of remifentanil Ce was significantly lower in Group D than in Group S (2.15 ± 0.40 ng/mL vs. 2.66 ± 0.36 ng/mL, p = 0.023). The EC95 (95% CI) of remifentanil Ce was also significantly lower in Group D [2.75 (2.67-2.78) ng/mL] than in Group S [3.16 (3.06-3.18) ng/mL]. Emergence and recovery variables did not differ between the two groups. CONCLUSION: The remifentanil EC50 to prevent cough after propofol-remifentanil anesthesia was significantly lower (approximately 19%) when a combination of remifentanil and 0.5 µg/kg dexmedetomidine was used than when remifentanil infusion alone was used in patients undergoing nasal surgery. Therefore, the Ce of remifentanil may be adjusted to prevent emergence cough when used in combination with dexmedetomidine. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03622502 , August 9, 2018).

A phytoestrogen secoisolariciresinol diglucoside induces browning of white adipose tissue and activates non-shivering thermogenesis through AMPK pathway.

Secoisolariciresinol diglucoside (SDG) is the main phytoestrogen component of flaxseed known as an antioxidant. Current study focused on the effect of SDG in white adipose tissue (WAT) browning. Browning of WAT is considered as a promising treatment strategy for metabolic diseases. To demonstrate the effect of SDG as an inducer of browning, brown adipocyte markers were investigated in inguinal WAT (iWAT) of high fat diet-fed obese mice and genetically obese db/db mice after SDG administration. SDG increased thermogenic factors such as uncoupling protein 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha and PR domain containing 16 in iWAT and brown adipose tissue (BAT) of mice. Similar results were shown in beige-induced 3T3-L1 adipocytes and primary cultured brown adipocytes. Furthermore, SDG increased factors of mitochondrial biogenesis and activation. We also observed SDG-induced alteration of AMP-activated protein kinase α (AMPKα). As AMPKα is closely related in the regulation of adipogenesis and thermogenesis, we then evaluated the effect of SDG in AMPKα-inhibited conditions. Genetic or chemical inhibition of AMPKα demonstrated that the role of SDG on browning and thermogenesis was dependent on AMPKα signaling. In conclusion, our data suggest SDG as a potential candidate for improvement of obesity and other metabolic disorders.

Reactive Oxygen Species-Producing Myeloid Cells Act as a Bone Marrow Niche for Sterile Inflammation-Induced Reactive Granulopoiesis.

Both microbial infection and sterile inflammation augment bone marrow (BM) neutrophil production, but whether the induced accelerated granulopoiesis is mediated by a common pathway and the nature of such a pathway are poorly defined. We recently established that BM myeloid cell-derived reactive oxygen species (ROS) externally regulate myeloid progenitor proliferation and differentiation in bacteria-elicited emergency granulopoiesis. In this article, we show that BM ROS levels are also elevated during sterile inflammation. Similar to in microbial infection, ROS were mainly generated by the phagocytic NADPH oxidase in Gr1+ myeloid cells. The myeloid cells and their ROS were uniformly distributed in the BM when visualized by multiphoton intravital microscopy, and ROS production was both required and sufficient for sterile inflammation-elicited reactive granulopoiesis. Elevated granulopoiesis was mediated by ROS-induced phosphatase and tensin homolog oxidation and deactivation, leading to upregulated PtdIns(3,4,5)P3 signaling and increased progenitor cell proliferation. Collectively, these results demonstrate that, although infection-induced emergency granulopoiesis and sterile inflammation-elicited reactive granulopoiesis are triggered by different stimuli and are mediated by distinct upstream signals, the pathways converge to NADPH oxidase-dependent ROS production by BM myeloid cells. Thus, BM Gr1+ myeloid cells represent a key hematopoietic niche that supports accelerated granulopoiesis in infective and sterile inflammation. This niche may be an excellent target in various immune-mediated pathologies or immune reconstitution after BM transplantation.

Comparison of Pentax Airway Scope and Macintosh laryngoscope for orotracheal intubation in children: A randomised non-inferiority trial.

BACKGROUND: Pentax Airway Scope (AWS) is a recently developed videolaryngoscope for use in both normal and difficult airways, yet its use in paediatric patients has not been established. The purpose of this study was to evaluate the efficacy of the Pentax AWS regarding intubation time, laryngeal view and ease of intubation in paediatric patients with normal airway, compared to Macintosh laryngoscope. METHOD: A total of 136 paediatric patients aged 1-10 with American Society of Anaesthesiologists physical status I or II undergoing general anaesthesia were randomly allocated into two groups: Macintosh laryngoscope (n = 68) and Pentax Airway Scope (n = 68). Primary outcome was intubation time. Cormack-Lehane laryngeal view grade, application of optimal laryngeal external manipulation, intubation difficulty scale, intubation failure rate and adverse events were also measured. RESULT: No significant difference was observed between the two groups regarding intubation time (P = 0.713). As for the laryngeal view grade, the Pentax group resulted in lower graded cases compared to the Macintosh group (P = 0.000). No optimal laryngeal external manipulation application was required in the Pentax group. Intubation difficulty scale resulted in lower values for Pentax group (P = 0.001). Failure rate was not different between the two groups (P = 0.619). There were significantly more teeth injury cases in the Pentax group than Macintosh group (P = 0.042). CONCLUSION: Pentax Airway Scope provided similar intubation time and success rate, while improving laryngeal view, compared to Macintosh laryngoscopy in children with normal airway. When using Pentax AWS in children, however, the risk of teeth injury may increase.

Randomized comparison of McGrath MAC videolaryngoscope, Pentax Airway Scope, and Macintosh direct laryngoscope for nasotracheal intubation in patients with manual in-line stabilization.

BACKGROUND: The objective of this study was to determine the clinical usefulness of videolaryngoscopes (VLs) by comparing the time to intubation (TTI) and the ease of intubation of McGrath MAC VL (MVL), Pentax Airway Scope VL (PVL), and Macintosh direct laryngoscope (DL) during nasotracheal intubation using manual in-line stabilization to simulate difficult airways. METHODS: One hundred and twenty patients were randomly assigned to the MVL group (n = 40), the PVL group (n = 40), and the DL group (n = 40). Nasotracheal intubation was performed using MVL, PVL, or DL, according to group assignments. The primary outcome was TTI and secondary outcomes were glottic view, ease of intubation, and bleeding. RESULTS: The TTI was significantly shorter in the MVL group than in the DL group (45 sec vs 57 sec; difference in means: - 12; 95% confidence interval [CI], - 21 to - 3; P = 0.01). The percentage of glottic opening and Cormack Lehane grade were significantly superior in the MVL and the PVL groups compared with the DL group (both P < 0.001). The intubation difficulty scale and numeric rating scale regarding ease of intubation were also significantly lower in the MVL and PVL groups than in the DL group (all P < 0.007). The incidence of bleeding was significantly lower in the MVL group than in the DL group (3 vs 15, relative risk 0.2; 95% CI, 0.06 to 0.64; P = 0.001). CONCLUSION: This study showed that both MVL and PVL provided better visualization of the glottis and easier intubation, with less additional manipulation than DL during nasotracheal intubation in simulated difficult airways. Additionally, use of the MVL significantly shortened the TTI compared with the DL. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02647606); registered 6 January, 2016.

RéSUMé: CONTEXTE: L'objectif de cette étude était de déterminer l'utilité clinique des vidéolaryngoscopes (VL) en comparant le temps jusqu'à intubation (TTI) et la facilité d'intubation du VL McGrath MAC (MVL), du VL Pentax Airway Scope (PVL), et du laryngoscope avec lame Macintosh (DL) pour une intubation nasotrachéale avec stabilisation manuelle en ligne simulant des voies aériennes difficiles. MéTHODE: Cent vingt patients ont été aléatoirement alloués au groupe MVL (n = 40), au groupe PVL (n = 40) ou au groupe DL (n = 40). L'intubation nasotrachéale a été réalisée à l'aide du MVL, du PVL ou du DL selon l'attribution de groupe. Le critère d'évaluation principal était le TTI et les critères secondaires comprenaient la visualisation glottique, la facilité d'intubation et les saignements. RéSULTATS: Le TTI était significativement plus court dans le groupe MVL que dans le groupe DL (45 sec vs 57 sec; différence de moyennes : -12; intervalle de confiance [IC] 95 %, -21 à -3; P = 0,01). Le pourcentage d'ouverture glottique et le grade de Cormack et Lehane étaient significativement supérieurs dans les groupes MVL et PVL par rapport au groupe DL (P < 0,001 pour les deux). L'échelle de difficulté d'intubation et l'échelle d'évaluation numérique concernant la facilité d'intubation étaient également significativement plus basses dans les groupes MVL et PVL que dans le groupe DL (tous P < 0,007). L'incidence de saignements était significativement plus basse dans le groupe MVL que dans le groupe DL (3 vs 15, risque relatif 0,2; IC 95 %, 0,06 à 0,64; P = 0,001). CONCLUSION: Cette étude a démontré que le MVL et le PVL procuraient tous deux une meilleure visualisation glottique et une intubation plus facile, avec moins de manipulations supplémentaires qu'un DL pendant l'intubation nasotrachéale de voies aériennes difficiles simulées. En outre, l'utilisation d'un MVL a significativement réduit le TTI par rapport à un DL. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT02647606); enregistrée le 6 janvier 2016.

Efficacy of Ultrasound-Guided Serratus Plane Block on Postoperative Quality of Recovery and Analgesia After Video-Assisted Thoracic Surgery: A Randomized, Triple-Blind, Placebo-Controlled Study.

BACKGROUND: The optimal regional technique for analgesia and improved quality of recovery after video-assisted thoracic surgery (a procedure associated with considerable postoperative pain) has not been established. The main objective in this study was to compare quality of recovery in patients undergoing serratus plane block (SPB) with either ropivacaine or normal saline on the first postoperative day. Secondary outcomes were analgesic outcomes, including postoperative pain intensity and opioid consumption. METHODS: Ninety patients undergoing video-assisted thoracic surgery were randomized to receive ultrasound-guided SPB with 0.4 mL/kg of either 0.375% ropivacaine (SPB group) or normal saline (control group) after anesthetic induction. The primary outcome was the 40-item Quality of Recovery (QoR-40) score at 24 hours after surgery. The QoR-40 questionnaire was completed by patients the day before surgery and on postoperative days 1 and 2. Pain scores, opioid consumption, and adverse events were assessed for 2 days postoperatively. RESULTS: Eighty-five patients completed the study: 42 in the SPB group and 43 in the control group. The global QoR-40 scores on both postoperative days 1 and 2 were significantly higher in the SPB group than in the control group (estimated mean difference 8.5, 97.5% confidence interval [CI], 2.1-15.0, and P = .003; 8.5, 97.5% CI, 2.0-15.1, and P = .004, respectively). The overall mean difference between the SPB and control groups was 8.5 (95% CI, 3.3-13.8; P = .002). Pain scores at rest and opioid consumption were significantly lower up to 6 hours after surgery in the SPB group than in the control group. Cumulative opioid consumption was significantly lower up to 24 hours postoperatively in the SPB group. CONCLUSIONS: Single-injection SPB with ropivacaine enhanced the quality of recovery for 2 days postoperatively and improved postoperative analgesia during the early postoperative period in patients undergoing video-assisted thoracic surgery.

Effect of Mild Hypercapnia on Lung Oxygenation in Sitting Position During Shoulder Arthroscopy Under General Anesthesia.

BACKGROUND Mild hypercapnia is permitted during surgeries in sitting position under general anesthesia to maintain cerebral regional oxygen saturation (rSO2). However, since hypoventilation may cause gas exchange impairment, we evaluated effects of mild hypercapnia on lung oxygenation during shoulder arthroscopy in sitting position. MATERIAL AND METHODS Forty patients were randomly allocated to a normocapnia group (ETCO2 35 mmHg, n=20) or a hypercapnia group (45 mmHg, n=20). The mean arterial pressure (MAP), heart rate (HR), and rSO2 were measured 5 min after intubation in supine position (T0), and at 2, 4, 6, 8, 10, 20, 30, 40, 50, and 60 min of remaining in sitting position (T1-10). Arterial blood gas was analyzed at T0 and T5. The oxygenation index (PaO2/FiO2) and dead-space ventilation ratio (Vd/Vt) were calculated. RESULTS There were no differences in PaO2/FiO2 at T0 and T5 between the 2 groups. At T5, the Vd/Vt was higher in the normocapnia group than in the hypercapnia group (p=0.04). The Vd/Vt at T5 increased from T0 in the normocapnia group. The incidence of cerebral desaturation in the hypercapnia group (0/20) was lower than in the normocapnia group (5/20) (p=0.047). Among rSO2, MAP, and HR, only changes in rSO2 over time between the 2 groups differed significantly (p=0.048). CONCLUSIONS Mild hypercapnia did not decrease lung oxygenation in sitting position, probably due to attenuation of the increase in dead-space ventilation ratio. Since hypercapnia maintained rSO2 without changes in oxygenation index and hemodynamic parameters, mild hypercapnia should be maintained during shoulder arthroscopy in sitting position under general anesthesia.

The effect of dexmedetomidine pretreatment on the median effective bolus dose of propofol for facilitating laryngeal mask airway insertion.

BACKGROUND: We designed this study to investigate the effect of dexmedetomidine (1 µg/kg) pretreatment on the median effective dose (ED50) of propofol for facilitating successful laryngeal mask airway (LMA) insertion compared to propofol alone. METHODS: Forty patients were randomized to either the control group (n = 21) or the dexmedetomidine group (n = 19). After infusion of normal saline or dexmedetomidine 1 µg/kg over 10 min, 1 % lidocaine 0.5 mg/kg, followed by propofol 2.5 mg/kg was administered and the laryngeal mask airway was inserted without muscle relaxants. The ED50 of propofol for successful LMA insertion was determined by the modified Dixon's up-and-down method. The ED50 and ED95 were also calculated using an isotonic regression method, based on the pooled adjacent-violators algorithm-adjusted response rate, and the confidential interval (CI) was estimated using a bootstrap approach. RESULTS: The ED50 of propofol for smooth insertion of the LMA was significantly higher in the control group than in the dexmedetomidine group (3.1 ± 0.4 vs 1.9 ± 0.3 mg/kg, P < 0.001). From isotonic regression analysis using a bootstrap approach, the ED50 and ED95 of propofol was 2.9 mg/kg (83 % CI 2.5-3.3 mg/kg) and 3.9 mg/kg (95 % CI 3.5-4.0 mg/kg) in the control group, and 1.8 mg/kg (83 % CI 1.8-2.1 mg/kg) and 2.4 mg/kg (95 % CI 2.0-2.5 mg/kg) in the dexmedetomidine groups, respectively. The apnea time was not significantly different between the two groups. CONCLUSIONS: Pretreatment with dexmedetomidine 1 µg/kg could reduce the propofol requirement by 38 % for facilitating LMA insertion without prolonged respiratory depression and hemodynamic instability.

Comparison of Intravenous Dexmedetomidine and Midazolam for Bispectral Index-Guided Sedation During Spinal Anesthesia.

BACKGROUND Despite the high frequency of hypotension during spinal anesthesia with proper sedation, no previous report has compared the hemodynamic effects of dexmedetomidine and midazolam sedation during spinal anesthesia. We compared the effects of bispectral index (BIS)-guided intravenous sedation using midazolam or dexmedetomidine on hemodynamics and recovery profiles in patients who underwent spinal anesthesia. MATERIAL AND METHODS One hundred and sixteen adult patients were randomly assigned to receive either midazolam (midazolam group; n=58) or dexmedetomidine (dexmedetomidine group; n=58) during spinal anesthesia. Systolic, diastolic, and mean arterial pressures; heart rates; peripheral oxygen saturations; and bispectral index scores were recorded during surgery, and Ramsay sedation scores and postanesthesia care unit (PACU) stay were monitored. RESULTS Hypotension occurred more frequently in the midazolam group (P<0.001) and bradycardia occurred more frequently in the dexmedetomidine group (P<0.001). Mean Ramsay sedation score was significantly lower in the dexmedetomidine group after arrival in the PACU (P=0.025) and PACU stay was significantly longer in the dexmedetomidine group (P=0.003). CONCLUSIONS BIS-guided dexmedetomidine sedation can attenuate intraoperative hypotension, but induces more bradycardia, prolongs PACU stay, and delays recovery from sedation in patients during and after spinal anesthesia as compared with midazolam sedation.

Male patients require higher optimal effect-site concentrations of propofol during i-gel insertion with dexmedetomidine 0.5 µg/kg.

BACKGROUND: The pharmacokinetics and pharmacodynamics of an anesthetic drug may be influenced by gender. The purpose of this study was to compare effect-site half maximal effective concentrations (EC50) of propofol in male and female patients during i-gel insertion with dexmedetomidine 0.5 µg/kg without muscle relaxants. METHODS: Forty patients, aged 20-46 years of ASA physical status I or II, were allocated to one of two groups by gender (20 patients per group). After the infusion of dexmedetomidine 0.5 µg/kg over 2 min, anesthesia was induced with a pre-determined effect-site concentration of propofol by target controlled infusion. Effect-site EC50 values of propofol for successful i-gel insertion were determined using the modified Dixon's up-and-down method. RESULTS: Mean effect-site EC50 ± SD of propofol for successful i-gel insertion was significantly higher for men than women (5.46 ± 0.26 µg/ml vs. 3.82 ± 0.34 µg/ml, p < 0.01). The EC50 of propofol in men was approximately 40% higher than in women. Using isotonic regression with a bootstrapping approach, the estimated EC50 (95% confidence interval) of propofol was also higher in men [5.32 (4.45-6.20) µg/ml vs. 3.75 (3.05-4.43) µg/ml]. The estimated EC95 (95% confidence interval) of propofol in men and women were 5.93 (4.72-6.88) µg/ml and 4.52 (3.02-5.70) µg/ml, respectively. CONCLUSIONS: During i-gel insertion with dexmedetomidine 0.5 µg/kg without muscle relaxant, male patients had higher effect-site EC50 for propofol using Schnider's model. Based on the results of this study, patient gender should be considered when determining the optimal dose of propofol during supraglottic airway insertion. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02268656. Registered August 26, 2014.

Implications of palonosetron in elderly patients undergoing laparoscopic cholecystectomy with respect to its anti-shivering effect.

BACKGROUND: The elderly are vulnerable to hypothermia and have a higher risk of cardiovascular events induced by marked increases in oxygen consumption due to shivering. Five-hydroxytryptamine-3 (5-HT3) receptor antagonists have been previously reported to reduce post-anesthesia shivering. AIM: In the present study, the authors investigated the effects of palonosetron, a new-generation 5-HT3 antagonist, on core hypothermia and the incidence of shivering after laparoscopic cholecystectomy in elderly patients. METHODS: Forty-eight patients (65-80 years) were randomly assigned to one of two groups and administered palonosetron 0.075 mg (palonosetron group, n = 24) or the same volume of normal saline (control group, n = 24) before anesthesia induction. Core body temperatures and hemodynamic variables were monitored during and after operation. Post-anesthetic shivering (PAS) and pain scores were obtained in a post-anesthetic care unit. RESULTS: Intraoperative esophageal temperature changed significantly over time (P = 0.010), but significant intergroup difference in change was not observed (P = 0.706). Furthermore, shivering frequencies were similar in the two groups (P = 0.610). However, postoperative pain scores at 30 min after entering the post-anesthesia care unit were significantly lower in the palonosetron group (P = 0.002). DISCUSSION: Regardless of the previously reported anti-shivering effect of 5-HT3 receptor antagonists, pre-operative palonosetron 0.075 mg did not influence perioperative hypothermia or PAS in this study. This discrepancy might be due to the dose responsiveness of palonosetron to PAS and relatively low incidence of PAS in the elderly. CONCLUSIONS: Pre-operative administration of palonosetron 0.075 mg did not influence perioperative hypothermia or post-anesthesia shivering in elderly patients undergoing laparoscopic cholecystectomy. However, palonosetron might be beneficial for reducing early postoperative pain in elderly patients with opioid-based patient-controlled analgesia.

McGrath Video Laryngoscopy Facilitates Routine Nasotracheal Intubation in Patients Undergoing Oral and Maxillofacial Surgery: A Comparison With Macintosh Laryngoscopy.

PURPOSE: The McGrath video laryngoscope (VL) offers excellent laryngoscopic views and increases the success rate of orotracheal intubation in patients with normal and difficult airways. The purpose of this randomized controlled trial was to compare the McGrath VL with the Macintosh laryngoscope to investigate the efficacy of the McGrath VL for routine nasotracheal intubation in patients with an expected normal airway. MATERIALS AND METHODS: To address the research purpose, the efficacy of the McGrath VL for routine nasotracheal intubation was compared with that of the Macintosh laryngoscope. The predictor variable was the laryngoscopic technique (McGrath VL vs Macintosh laryngoscope). The outcome variables were the time to successful intubation, laryngoscopic views before and after optimal external laryngeal manipulation (OELM), use of Magill forceps, ease of intubation, and severity of oropharyngeal bleeding. RESULTS: Data from 35 patients undergoing oral and maxillofacial surgery were assessed. The time to intubation was 10.5 seconds shorter in the McGrath group than in the Macintosh group (34.4 ± 13.7 vs 44.9 ± 15.6 seconds; P = .004). The incidence of grade 1 glottic view before OELM was higher in the McGrath group than in the Macintosh group (83 vs 57%; P = .019). The frequency of Magill forceps use was lower in the McGrath group than in the Macintosh group (6 vs 34%; P = .003). CONCLUSION: McGrath VL facilitates routine nasotracheal intubation in expected normal airways by providing a shorter intubation time and better laryngoscopic views compared with the Macintosh laryngoscope.

The effect of low-dose dexmedetomidine on hemodynamics and anesthetic requirement during bis-spectral index-guided total intravenous anesthesia.

The purpose of this study was to evaluate the effects of low-dose dexmedetomidine on hemodynamics and anesthetic requirements during propofol and remifentanil anesthesia for laparoscopic cholecystectomy. Thirty adult patients were randomly allocated to receive dexmedetomidine infusion of 0.3 µg/kg/h (dexmedetomidine group, n = 15) or comparable volumes of saline infusion (control group, n = 15). Target controlled infusion of propofol and remifentanil was used for anesthetic induction and maintenance, and adjusted in order to maintain a bispectral index of 40-55 and hemodynamic stability. We measured hemodynamics and recorded total and mean infused dosages of propofol and remifentanil. For anesthesia induction and maintenance, mean infused doses of propofol (121 ± 27 vs. 144 ± 29 µg/kg/min, P = 0.04) and remifentanil (118 ± 27 vs. 150 ± 36 ng/kg/min, P = 0.01) were lower in the dexmedetomidine group than in the control group, respectively. The dexmedetomidine group required 16 % less propofol and 23 % less remifentanil. During anesthetic induction and maintenance, the dexmedetomidine group required fewer total doses of propofol (9.6 ± 2.3 vs. 12.4 ± 3.3 mg/kg, P = 0.01) and remifentanil (9.6 ± 3.4 vs. 12.7 ± 2.6 µg/kg, P = 0.01). The change in mean arterial pressure over time differed between the groups (P < 0.05). Significantly lower mean arterial pressure was observed in the dexmedetomidine group than in the control group at immediately and 5 min after pneumoperitoneum. The time to extubation after completion of drug administration did not differ between the groups (P = 0.25). This study demonstrated that a low-dose dexmedetomidine infusion of 0.3 µg/kg/h reduced propofol and remifentanil requirements as well as hemodynamic change by pneumoperitoneum without delayed recovery during propofol-remifentanil anesthesia for laparoscopic cholecystectomy.

Ultrasound evaluation of the radial artery for arterial catheterization in healthy anesthetized patients.

The purpose of this study was to assess the anatomy of the radial artery using ultrasound in anesthetized patients, and to correlate its anatomical data with patients' characteristics. The success rate of radial artery cannulation using ultrasound was also evaluated to analyze the relationship between the anatomical data and the success rate. Study 1 One hundred ninety-five patients scheduled for general anesthesia were enrolled. Ultrasound measurements were obtained when the vital signs were stable after anesthesia induction. The wrist joint of patients were extended to 30°. The diameter and depth of the radial artery, and the angle between the radial artery and skin surface were measured using ultrasound. Anatomical data were correlated with patients' characteristics. Study 2 Arterial cannulation was performed in 125 patients using long-axis in-plane technique to evaluate the success rate using ultrasound. Study 1 The diameter of the radial artery was mean value of 2.2 ± 0.4 mm and larger than 0.9 mm in all patients. It had significant correlation with body surface area (BSA) (Pearson correlation 0.292, P < 0.001). The incidence of abnormal angle between the radial artery and skin surface was significantly higher in elderly patients (≥65 years) than young patients (P = 0.017). Study 2 The first attempt success rate of arterial catheterization using ultrasound was 92.5 % using long-axis in-plane technique, regardless of patient's characteristics. For small sized adult patients, a 22G angio-catheter should be used during radial artery cannulation, because the radial artery diameter significantly correlated with BSA in healthy anesthetized patients. In addition, ultrasound-guided catheterization is recommended in elderly patients because the incidence of abnormal angle between the radial artery and skin surface was high.

Preoperative serum lactate cannot predict in-hospital mortality after decompressive craniectomy in traumatic brain injury.

PURPOSE: Despite the utility of serum lactate for predicting clinical courses, little information is available on the topic after decompressive craniectomy. This study was conducted to determine the ability of perioperative serum lactate levels to predict in-hospital mortality in traumatic brain-injury patients who received emergency or urgent decompressive craniectomy. METHODS: The medical records of 586 consecutive patients who underwent emergency or urgent decompressive craniectomy due to traumatic brain injuries from January 2007 to December 2014 were retrospectively analyzed. Pre- and intraoperative serum lactate levels and base deficits were obtained from arterial blood gas analysis results. RESULTS: The overall mortality rate after decompressive craniectomy was 26.1 %. Mean preoperative serum lactate was significantly higher in the non-survivors (P = 0.034) than the survivors but had no significance for predicting in-hospital mortality in the multivariate regression analysis (P = 0.386). Rather, preoperative Glasgow Coma Score was a significant predictor for in-hospital mortality (hazard ratio 0.796, 95 % confidence interval 0.755-0.836, P < 0.001). CONCLUSION: Preoperative lactate level is not an independent predictor of in-hospital mortality after decompressive craniectomy in traumatic brain-injury patients.