Single pretreatment of remifentanil may reduce pain after propofol and rocuronium injection in rapid sequence induction

최윤지,박한석,이한,윤승주 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.63 No.5

Background: We designed this double-blind, placebo-controlled study to compare the efficacy of remifentanil in reducing the pain of both propofol and rocuronium injection during rapid-sequence induction. Methods: Ninety-five patients, scheduled for elective surgery under general anesthesia, were divided into 3 groups:saline (Group S, n = 31), remifentanil 1 μg/kg (Group R, n = 32), and lidocaine 1.5 mg/kg (Group L, n = 32) were administered after tourniquet application. The occlusion was released after 1 min and 5 ml of 1% propofol was injected over 10 s. Pain on propofol injection was evaluated by a 10-point verbal numeric rating scale (VNRS). The rest of the induction dose of propofol and 1 mg/kg of rocuronium, were injected. Pain on rocuronium injection was evaluated by a four-point score (FPS). Results: The VNRS of propofol injection was as follows: R (0.78) = L (1.34) < S (4.26). The incidence of withdrawal response due to rocuronium was as follows: R (6.3%) < L (53.1%) < S (83.9%). The FPS of rocuronium injection was as follows: R (0.81) < L (1.78) < S (2.93). Conclusions: Pretreatment with a bolus of remifentanil was effective in simultaneously reducing injection pain of propofol and rocuronium. In addition, remifentanil pretreatment was more effective in suppression of withdrawal response by rocuronium than lidocaine. Background: We designed this double-blind, placebo-controlled study to compare the efficacy of remifentanil in reducing the pain of both propofol and rocuronium injection during rapid-sequence induction. Methods: Ninety-five patients, scheduled for elective surgery under general anesthesia, were divided into 3 groups:saline (Group S, n = 31), remifentanil 1 μg/kg (Group R, n = 32), and lidocaine 1.5 mg/kg (Group L, n = 32) were administered after tourniquet application. The occlusion was released after 1 min and 5 ml of 1% propofol was injected over 10 s. Pain on propofol injection was evaluated by a 10-point verbal numeric rating scale (VNRS). The rest of the induction dose of propofol and 1 mg/kg of rocuronium, were injected. Pain on rocuronium injection was evaluated by a four-point score (FPS). Results: The VNRS of propofol injection was as follows: R (0.78) = L (1.34) < S (4.26). The incidence of withdrawal response due to rocuronium was as follows: R (6.3%) < L (53.1%) < S (83.9%). The FPS of rocuronium injection was as follows: R (0.81) < L (1.78) < S (2.93). Conclusions: Pretreatment with a bolus of remifentanil was effective in simultaneously reducing injection pain of propofol and rocuronium. In addition, remifentanil pretreatment was more effective in suppression of withdrawal response by rocuronium than lidocaine.

Injection profile effects on low speed axial compressor stability enhancement

Lim, Hyung-Soo,Bae, Hyo-Jo,Lim, Young-Cheon,Song, Seung-Jin,Kang, Shin-Hyoung,Yang, Soo-Seok 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.6

This study presents stability enhancement of a four-stage low speed axial compressor with different injection profiles. The injection profiles include one-step injection, multi-step injection, and continuous injection. For the tip injection, eight Coanda-shaped nozzles have been installed at eight equally spaced circumferential locations upstream of the first stage rotor. Two external blowers injected air steadily through the Coanda-shaped nozzles. With tip injection, the compressor operation range has been extended. To analyze stall margin improvement, spatial Fourier transform (SFT) has been performed. The coefficient of SFT (SFC) is a complex number, containing information about the magnitude and the phase of SFC. By analyzing the distribution of the magnitude and the phase of SFC, the stall onset point has been verified. Furthermore, the injection flow rate has been changed during injection process to examine the possibility of attaining an additional flow extension. Increasing the injection rate during stabilization can bring about additional operation range extension. These results suggest a new injection method to reduce the total amount of the injection air.

유리체강내 주입술 후 유리체 역류를 일으키는 인자

지동현(Donghyun Jee),김보윤(Bo Youn Kim),나태윤(Tae Yoon Ra) 대한검안학회 2010 Annals of optometry and contact lens Vol.9 No.2

목적: 유리체강내 주입술 후 발생하는 유리체 역류에 관여하는 위험인자를 분석하여 유리체 역류를 최소화시키는 방법을 알아보고자 하였다. 대상과 방법: 본원에서 베바시주맙 유리체강내 주입술을 받은 122명 122안을 대상으로 연구를 시행하였다. 유리체 역류의 정도는 주입술 후 발생하는 결막 수포의 최대 지름으로 측정하였고, 술 전 안압, 수정체의 유무, 공막창의 형태, 주사 바늘 제거 속도를 조사하여 유리체 역류에 영향을 주는 인자를 분석하였다. 결과: 술 전 안압의 변화와 수정체 유무에 따라 유리체 역류는 통계적으로 유의한 변화를 보이지 않았다. 주사바늘주입 형태에 따라 결막 수포의 지름은 수직주입군에 비해 터널주입군에서 역류량을 유의하게 줄일 수 있었다(p=0.004). 주사바늘을 제거 속도에 따라 결막 수포의 지름은 바늘을 빠르게 제거한 군에 비하여 주사바늘을 천천히 제거할 때 유의하게 역류가 적게 발생함을 확인할 수 있었다(p<0.001). 결론: 유리체강 내 주입술 시 터널형태 공막창을 만들어 주입 후 천천히 주사바늘을 제거하는 것이 유리체 역류를 줄일 수 있는 좋은 방법으로 기대된다. Purpose: To analyze the factors affecting the vitreous reflux after intravitreal (IV) injection. Methods: A prospective study was conducted for 122 eyes of 122 patients who had undergone intravitreal Bevacizumab (AvastinⓇ) injection. The amount of vitreal reflux was measured as the conjunctival blebs size by using caliper after IV injection. We investigated the pre-injection IOP, status of lens, injection technique, and speed of needle removal as risk factors and analyzed the factors affecting the vitreous reflux after IV injection by multivariate linear regression test. Results: There was no statistically significant correlation between pre-injection IOP and mean conjunctival bleb size (CBS) (p=0.084). The relationship between mean conjunctival bleb size and lens status was not statistically significant, (1.95±1.84 mm) in phakic eyes and (2.18±1.66 mm) in pseudophakic eyes (p=0.723). The relationship between mean CBS and injection technique was statistically significant (p=0.004). The mean CBS was less with the tunneled scleral injection (1.87±1.80 mm) than in eyes undergoing the straight scleral injection (2.03±1.80 mm). Also the mean CBS was statistically less with the slow group of needle removal (1.54±1.58 mm) than in eyes undergoing the fast group of needle removal (3.36±1.70 mm) (p<0.001). Conclusions: Slow removal of needle and the tunneled scleral incision can be expected to decrease the vitreal reflux after intravitreal injection.

1D 시뮬레이션 기반 GDI 인젝터의 비선형적 분사 특성 해석에 대한 연구

이진우,문석수,허동한,강진석 한국분무공학회 2023 한국액체미립화학회지 Vol.28 No.4

Multi-injection scheme is being applied to GDI combustion to reduce PM and PN emission to meet the EU7 regulation. However, very short injection duration encounters the ballistic injection region, which injection quantity does not increase linearly with injection duration when applying multi-injection. In this study, numerical studies were conducted to reveal the cause of ballistic injection and the effect of design parameters on ballistic region using 1-D simulation, AMESim. Injection rate and injection quantity were compared with experiment to validate the established model, which showed the accuracy with 10% error. The model revealed that the tendency of ballistic region coincides with the needle motion behavior, which means that parameters at the upper part of needle such as electro-magnetic force, needle spring force and needle friction force have dominant effect on ballistic injection. To figure out the effect of electro-magnetic and needle friction force on ballistic, those parameters were varied to plus and minus 10% with model. The result showed that those parameters clearly changed the ballistic region characteristics, however, the impact became insignificant for outside of ballistic region, which means that the ballistic injection is mainly influenced by initial motion of injector needle.

Reevaluation of the Necessity of Iron Injection to Newborn Piglets

Yu, I.T.,Lin, J.,Wu, J.F.,Yen, H.T.,Lee, S.L.,Yang, T.S. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.1

The growth and immune responses to endotoxin lipopolysaccharide (LPS) challenge ( $20{\mu}g/kg$) of piglets with and without a iron dextran injection (Fe, 200 mg/head) two days after birth are compared. Sixty-four newborn piglets from eight litters were allocated randomly to one of four treatments. The control received no iron dextran and only saline (Sal) injection on the second and fifteenth day after birth (Sal-Sal). The remaining three groups received Fe-Sal, Sal-LPS, Fe-LPS treatments respectively. On fifteen days of age, blood samples of piglets were taken at 0 h, 1 h, 2 h and 4 d after saline or LPS injection to determine immune functions and blood characteristics. The trial terminated when the pig reached 56 days and the average daily gain of piglets was then measured. Daily gain, serum immunoglobulin G (IgG) concentration and red blood cell counts did not vary significantly among the four groups at any measuring times. Serum tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) concentration increased sharply 1 h after LPS injection. However, iron injection did not change TNF-${\alpha}$ concentration responds to LPS injection. White blood cell counts of two LPS injection groups were significantly lowered 1 h following the injection. In contrast, serum lactoferrin concentration had increased significantly 1 and 2 h postinjection. Furthermore, iron injection produced no further effects on these two criteria. Iron injection increased the hemoglobin (Hb) concentration of piglets at any measuring time, and LPS injection lowered Hb concentration. In conclusion, a 200 mg/head of iron dextran injection on the second day after birth increased Hb concentration, had no detrimental effect on the immune responses and growth of piglets. Moreover, if creep feed (175 mg Fe/kg feed) is provided from d 7 after birth, the Fe-injection does not contribute to overall performance of piglets and may not be a necessity in practice.

Penetration Processes of Soft Solid Materials by Needle-Free Micro-Injections

( Muh Rong Wang ),( Chun Hsien Chiu ),( Chien Chih Huang ),( Li Jay Cheng ),( Yang Sheng Huang ),( Min Chen ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

Penetration characteristics of the single pulse micro-jets into the soft solid materials of gelatin gels and porcine colons are investigated in this paper. The images of penetration processes were taken by IDT high-speed digital camera at the sampling rate of 2500 frames per second. The evolution of the penetration process, penetration depth, volume of infection and penetration rate is investigated. Gelatin gel is a good model material for the observation of the penetration processes because of the translucent property. In vitro penetrations of porcine colons were also tested for the prior study of endoscopic needle-free injection. The penetration test was performed under the single-pulsed mode at injection time of 0.1, 0.25 and 0.5 seconds. The injection pressure was in the range of 50 to 125 bar. The diameter of the injectors, do, is 250 and 300 m. According to the high-speed photos of the gel penetration, the injection processes can be described as four steps: 1. Initial compression period: the elastic compression of the soft solid material at the penetration site and the neighborhood. 2. Material failure period: the jet penetrates inside the gelatin gel including the initial surface crack and growth of the injected volume. 3. Elastic rebounding period: It takes place when the injection is stopped. The injected water starts to be squeezed out of the gelatin gel under the compression of the gelatin gel during the elastic relaxation processes until the final penetration depth and width. 4. Final stable period: the penetration depth and width inside the gelatin gel are fixed afterward. Furthermore, the injection tests on the porcine colon show the penetration into submucosal layer is possible under the injection pressure less than 60 bar with the orifice of 300 m and injection time of 0.1 sec. The injection power is 16 W under this condition. However, higher injection power is needed for the punch through injection of porcine colon. The failure stress of the porcine colon is 1.077 0.333 MPa by the deep penetration test.

1형 미숙아망막병증의 치료로서 일차 유리체강내 라니비주맙 주입술의 효과

정규철(Gyu Chul Chung),문성혁(Sung-Hyuk Moon) 대한안과학회 2017 대한안과학회지 Vol.58 No.9

Purpose: To evaluate the effectiveness and safety of primary intravitreal ranibizumab injection as a treatment for retinopathy of prematurity. Methods: Retrospective analysis of the medical records of patients diagnosed with retinopathy of prematurity and treated with intravitreal ranibizumab injection from January 1, 2013 to January 1, 2016 was performed. We complied with the standards for ‘prethresold, type 1’ established by the Early Treatment of Retinopathy of Prematurity study for intravitreal ranibizumab injection. The follow-up period after injection was at least 9 months. Patients who received additional treatment such as laser photocoagulation or intravitreal injection without reactivation of retinopathy of prematurity were excluded. Results: A total of 21 patients (39 eyes) were included in this study. Nine (16 eyes) were male and 12 (23 eyes) were female. The average duration between treatment decision and intravitreal ranibizumab injection was 2.1 ± 1.5 days. Complete regression of the plus sign occurred 18.2 ± 9.1days after injection. One eye with reactivation was treated with panretinal laser photocoagulation while four other eyes with reactivation were treated with intravitreal bevacizumab injection. There were 87.1% (34/39) eyes that underwent primary intravitreal ranibizumab injection with stable results without any reactivation. There were no systemic complications related to intravitreal ranibizumab injection. Conclusions: Primary intravitreal ranibizumab injection as a treatment for retinopathy of prematurity showed good efficacy and safety. However, thorough evaluation is needed after primary intravitreal ranibizumab injection due to the potential for reactivation. Long-term monitoring is needed after intravitreal ranibizumab injection. J Korean Ophthalmol Soc 2017;58(9):1080-1086

승용 디젤 CRDI 엔진의 다단 분사가 연소 및 배기 특성에 미치는 영향

노현구(Hyun Gu Roh),이창식(Chang Sik Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper described the effect of the multiple injection on the stability of idle-operating and emission characteristics in a common rail direct injection diesel engine at various operating conditions. In order to investigate the influence of multiple injections in a diesel engine, the fuel injection timing was varied two pilot injections and one main injection at various conditions. The experimental apparatus is consisted of DI diesel engine with 4 cylinders, EC dynamometer, multi-stage injection control system, and exhaust emissions analyzer. The combustion pressure was measured using a piezoelectric pressure sensor installed the hole of glow plug. Detection of the crank angle of rotating engine was used for the crankshaft position sensor of the magnetic inductive type installed. The exhaust emissions from the engine were measured by using transmitted light type soot measuring instrument and NOx, HC and CO analyzer. The operating point was analyzed for the main, pilot-main, pilot-pilot-main strategy were tested. It is revealed that the combustion pressure was smoothly near the TDC and the coefficient of variations is reduced due to the effect of pilot injection. Also, NOx emissions are dramatically decreased with pilot injection because the rate of heat release. However Soot is increased at early pilot injection at main injection.

Influence of the fuel spray angle and the injection strategy on the emissions reduction characteristics in a diesel engine

Kim, Hyung Jun,Park, Su Han,Lee, Chang Sik SAGE Publications 2015 Proceedings of the Institution of Mechanical Engin Vol.229 No.5

<P>This study describes the effects of the fuel injection angle and the multiple-injection strategies on the combustion, the emissions and the performance characteristics in a common-rail diesel engine. To conduct this investigation, a single-cylinder diesel engine with four valves was used, and various injection strategies with different parameters such as the spray angle, the timing and a single injection or multiple injections were applied. The combustion pressure, the heat release rate and the emissions were measured by a combustion and exhaust emissions analyser system. An injection spray angle of 156 degrees resulted in higher nitrogen oxide emissions than an injection spray angle of 60 degrees did, as the time between the first injection and the second injection increased. Also multiple injections resulted in lower levels of soot and hydrocarbon emissions than a single injection did. A multiple-injection strategy with a dwell time of 20-40 degrees crank angle before top dead centre and the first injection at 60 degrees crank angle before top dead centre or 50 degrees crank angle before top dead centre improved the engine power and lowered the fuel consumption compared with the results for a single injection.</P>

직접분사식 단기통 디젤엔진에서 다단분사에 따른 연소 및 배기특성

허정윤(Jeong Yun Heo),차준표(Junepyo Cha),윤승현(Seung Hyun Yoon),이창식(Chang Sik Lee) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

The purpose of this work is an experimental investigation combustion and emission characteristics in DI diesel engine applied multiple injection strategy. In order to analyze the effect of multiple injection, single-cylinder DI diesel engine was operated under electrically controlled fuel injection system. In this study, multiple injections were injected as two types of multiple injection that were defined as the pilot injection and the post injection. The pilot injection and the post injection was injected 30% of total fuel injections mass quantity. The results of multiple injection were compared to those of single injection and each multiple injection types. To investigate for a low speed engine and middle range load, the experimental conditions were conducted under a fixed engine speed and constant stoichiometric ratio condition. The combustion results show that each multiple injections decreases peak heat release rates but increases indicated mean effective pressure. The emissions results that pilot injection increases emissions but post injection reduces NO<SUB>x</SUB>, HC and CO emissions.