Premedication with dexmedetomidine in pediatric patients: a systematic review and meta-analysis

Premedication is important in pediatric anesthesia. This meta-analysis aimed to investigate the role of dexmedetomidine as a premedicant for pediatric patients. A systematic literature search was conducted to identify randomized controlled trials comparing dexmedetomidine premedication with midazolam or ketamine premedication or placebo in children. Two reviewers independently performed the study selection, quality assessment and data extraction. The original data were pooled for the meta-analysis with Review Manager 5. The main parameters investigated included satisfactory separation from parents, satisfactory mask induction, postoperative rescue analgesia, emergence agitation and postoperative nausea and vomiting. Thirteen randomized controlled trials involving 1190 patients were included. When compared with midazolam, premedication with dexmedetomidine resulted in an increase in satisfactory separation from parents (RD = 0.18, 95% CI: 0.06 to 0.30, p = 0.003) and a decrease in the use of postoperative rescue analgesia (RD = -0.19, 95% CI: -0.29 to -0.09, p = 0.0003). Children treated with dexmedetomidine had a lower heart rate before induction. The incidence of satisfactory mask induction, emergence agitation and PONV did not differ between the groups. Dexmedetomidine was superior in providing satisfactory intravenous cannulation compared to placebo. This meta-analysis suggests that dexmedetomidine is superior to midazolam premedication because it resulted in enhanced preoperative sedation and decreased postoperative pain. Additional studies are needed to evaluate the dosing schemes and long-term outcomes of dexmedetomidine premedication in pediatric anesthesia

(meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetra­azacyclo­tetra­deca­ne)copper(II) bis­(O,S-dibenzyl dithio­phosphate)

In the crystal structure of the title compound, [Cu(C16H36N4)](C14H14O2PS2)2, the CuII atom is located on an inversion center and is chelated by four N atoms of the macrocyclic meso-5,5,7,12,12,14- hexa­methyl-1,4,8,11-tetra­azacyclo­tetra­decane ligand in a square-planar geometry, with Cu—N distances of 2.013 (3) and 2.014 (3) Å. In the crystal structure, one O,S-dibenzyl dithio­phosphate counter-anion links with the CuII complex cation through N—H⋯O and N—H⋯S hydrogen bonding. During the synthesis, the structure of the anion re-arranged from O,O′-dibenzyl dithio­phosphate in the starting material to O,S-dibenzyl dithio­phosphate in the title compound

Numerical simulation of the blasting vibration response of shallow buried tunnel in complex urban environment

Base on the phase I project of Nanjing metro line IV, the blasting vibration response of shallow buried tunnel in complex urban environment was studied with ANSYS/LS-DYNA, the real load change was simulated with the loading way of measured stress curve, and there was a consistent between numerical simulation results and the measured data. The numerical results indicated that the velocity distribution in different directions were close in the close area (0-2 m); the vertical seismic wave attenuated at the fastest speed in the transferring process, and the radial seismic wave attenuated the fastest in the excavation direction ; in the distance from 2 m to 5 m, the tangential and radial vibration of the initiating side were both obviously larger than the other side of the core tube, which was still more violent than the vertical vibration, and the difference decreases with the distance increases. In the surrounding rocks , the radial vibration velocity was the biggest and attenuated at the fastest speed, which was close to linear attenuation ;the tangential vibration velocity is the smallest with the a relatively gentler damping, the vertical vibration attenuated until 8 m and then increased gradually and the resultant velocity obeyed the exponential damping law

Urinary paraquat concentration and white blood cell count as prognostic factors in paraquat poisoning

Purpose: To investigate the effect of white blood cell (WBC) and urinary paraquat (PQ) levels on prognostic factors in patients exposed to PQ intoxication using multivariate logistic regression analysis.Methods: A total of 104 subjects intoxicated with PQ between December 2015 and July 2016 were used in this retrospective study. They comprised patients who survived (n = 78), and patients who died (n = 26). Clinical features and prognostic parameters were analyzed in both groups. Multivariate logistic regression analysis was used to establish a prognostic correlation model based on results from single factor variables.Results: Comparison of demographic and clinical attributes between the two groups, survivors (n = 78) and non-survivors (n = 26), revealed that those who survived were not as old (33.3 ± 9.9 years) as nonsurvivors (41.5 ± 12.9 years). In addition, on admission, it was found that the survivors ingested lower amounts of PQ (31.6 ± 13.8 ml) than non-survivors (67.88 ± 31.2 ml). There were significant differences between the two groups with respect to WBC, neutrophils, lymphocytes, lactate dehydrogenase (LDH), creatine kinase (CK), amylase, uric acid (UA), pH, partial pressure of oxygen (PaO2), base excess (BE), lactic acid, and D-dimer levels (p < 0.05).Conclusion: WBC and urine PQ concentration have strong correlation with prognostic factors in PQ poisoning.Keywords: Paraquat intoxication, Dithionite test, Multivariate logistic analysis, Prognosis, Predictor

Study on wind resistance coefficient of double split wire arrangement

Shape coefficients of a single traverse and twin branch lines are examined through wind tunnel experiments and numerical simulations under different angle of attacks and wind speeds. It was found that the shape coefficient at angle of attack equaling to 0 is obviously smaller than the others. And the effects of Reynolds number are also large. The numerical results give difference between cases reaching 20 %, however, the experimental ones only 1.17 %. It is because that the initial condition of CFD is idealized but the wind tunnel experiment is closer to the reality