Effects of age on onset time and duration of sensory blockade in ultrasound guided supraclavicular block Abstract

Background and purpose: Involutive changes of brachial plexus occur with aging. The aim of this study was to determine if these changes would effect onset time and duration of sensory blockade in all four distal nerves of brachial plexus in middle aged (65 years). Materials and methods: Middle aged (N=22) and elderly patients (N=22) undergoing upper limb surgery received an ultrasound guided supraclavicular block with a mixture of local anesthetics (50 : 50, 0.5% levobupivacaine, 2% lidocaine). The prospective, observer-blinded study method is a previously validated step-up/step-down sequential model where the local anesthetic volume for each following patient is determined by the outcome of the previous block. The starting volume was 30 ml. Only the blocks with complete sensory blockade in all four regions of distal nerves were analyzed for the onset time and duration of sensory blockade. Results and conclusions: The mean (SD) block onset time was 25.8±0.6 min and the mean (SD) block duration was 151.5±8.9 min in the entire middle aged group. In the entire elderly group, the mean (SD) block onset time was 21±0.82 min and the mean (SD) block duration was 195.75±14.99 min. The difference in both, onset time and duration was significant (P=0.0002, 95%CI 3.352–6.248; P=0.0023, 95% CI 65.63–22.95, respectively). In conclusion, local anesthetics have a faster onset time and longer duration of sensory blockade in elderly due to alterations of peripheral nerves and increased sensitivity to local anesthetics

Perioperative volume replacement therapy for orthopic liver transplantation-observational, retrospective study

Cilj: Tijekom transplantacije jetre očekuju se značajni gubitci tjelesnih tekućina koje je potrebno nadoknaditi kristaloidnim i koloidnim otopinama te transfuzijom krvlju i krvnim derivatima. U studiji smo analizirali je li u petogodišnjem razdoblju promijenjen pristup intraoperacijskoj nadoknadi tekućina i krvnih derivata tijekom transplantacije jetre. Materijali i metode: U opservacijskoj retrospektivnoj studiji analizirali smo podatke ukupno 155 pacijenata kojima je transplantirana jetra u Kliničkoj bolnici Merkur, 79 tijekom 2015. godine i 76 tijekom 2010. godine. Analizirali smo ukupni gubitak krvi, ukupni uneseni volumen tekućina tijekom transplantacijskog postupka te volumen pojedinih vrsta tekućina (kristaloidi, koloidi, koncentrati eritrocita, svježe smrznuta plazma, trombociti). Statistička analiza rađena je Studentovim t-testom. Rezultati: Pacijenti su bili međusobno usporedivi po tjelesnoj masi i visini, MELD ljestvici. Ukupni gubitci krvi (ml) tijekom transplantacije jetre u 2015. i 2010. godini iznosili su: 6526± 4194 i 11122± 6685, P<0,001. Volumeni unesenih tekućina (ml) tijekom transplantacije jetre u 2015. i 2010. godini iznosili su: ukupni volumen tekućina 9640± 6017 i 18433 ± 7282, P< 0,001; kristaloidi 5077± 1443 i 5674± 2326, P=0,055; koloidi 1853± 814 i 2244± 1188, P=0,018; autologna krv 1097± 1160 i 1927± 2608, P=0,011; homologna krv 1293± 1247 i 2979± 2196, P<0,001; svježe smrznuta plazma 2244± 1523 i 5429± 1954, P<0,001; trombociti 349± 387 i 426± 313, P=0,176. Zaključci: Ovom studijom uočeno je značajno smanjenje ukupnog volumnog unosa, unosa koloidnih otopina, koncentrata eritrocita i svježe smrznute plazme tijekom transplantacije jetre u razdoblju od pet godina. Razlozi navedenog su ograničavanje perioperacijske volumne nadoknade u svrhu smanjivanja nepovoljnih učinaka volumnog preopterećenja. Ipak, najvažniji je faktor anestezijsko i kirurško iskustvo prikupljeno tijekom niza uspješnih godina u transplantacijskoj medicini.Aim: Significant fluid losses occur during liver transplantation, which need to be replaced. In this study, we analyzed whether fluid replacement strategies during liver transplantation have changed over a five-year period. Materials and Methods: In this observational, retrospective study, we collected data on 155 patients who underwent liver transplantation at the University Hospital «Merkur», 79 in 2015 and 76 in 2010. We analyzed total blood loss, total volume of replaced fluids and the volume of crystalloids, colloids, erythrocyte concentrates, fresh frozen plasma and platelets applied. We employed the Student t-test for statistical analysis. Results: Total blood losses (ml) in 2015 and 2010 were: 6526± 4194 and 11122± 6685, respectively, P<0,001. Volumes of replaced fluids (ml) in 2015 and 2010 were following: total fluid volume 9640± 6017 and 18433± 7282, P< 0,001; crystalline 5077± 1443 and 5674± 2326, P=0,055; colloids 1853± 814 and 2244± 1188, P=0,018 ; autologous blood 1097± 1160 and1927± 2608, P=0,011; homologous blood 1293± 1247 and 2979± 2196, P<0,001; fresh frozen plasma 2244± 1523 and 5429± 1954, P<0,001; platelets 349± 387 and 426± 313, P=0,176. Conclusions: This study showed a significant reduction in total fluid replacement, as well as in replacement of colloids, blood transfusion and fresh frozen plasma during liver transplantation over a period of five years. A possible explanation is a more restrictive perioperative fluid replacement strategy employed with the aim of reducing adverse effects of volume overload as well as a growing experience acquired over a number of successful years in transplantation medicine

Comparison of minimum effective volume of local anesthetic for ultrasound guided supraclavicular block (MEAV95) in elderly and middle aged patients

Backgrund and purpose: The aim of this study was to determine the minimum effective volume of local anesthetic (LA) required to produce an efficient supraclavicular block in 95% of patients (MEAV95) using an ultrasound (US)-guided technique in an elderly (>65 y) and a middle aged group (<45 y) of patients. Furthermore, we aimed to calculate potency ratio of LA between the groups. We assumed a reduced MEAV95 in elderly group. Matherials and Methods: Fourty-four patients (N=22 per group) undergoing upper limb surgery received a US-guided supraclavicular block. The study method is a previously validated step-up/step-down sequential model where the volume of LA for each following patient is determined according to the outcome of the previous block. The starting volume was 30 mL; in the case of block failure, the volume was increased by 5 ml. After successful block, the volume was reduced by 5 mL. MEAV95 was calculated using probit transformation and logistic regression. Potency ratio of LA is calculated using Fieller’s method. Results and Conclusions: The calculated minimum effective anesthetic volume in 95% of patients was 16.49 mL (95% CI, 12.23–20.75 mL) in elderly and 44.52 mL (95% CI, 19.05–69.99 mL) in middle aged group (95% CI, 0.7–55.3 mL, P=0.044). A potency ratio of LA between middle aged and elderly is 2.69 (95% CI 2.13 to 3.44). The minimum volume requirement for effective US-guided supraclavicular block in 95% of elderly patients was significantly reduced. A potency ratio of 2.69 indicates almost three times stronger LA potency in the elderly

Nonsuicidal Self-Injury (NSSI) in Serbia: Nationally representative sample study

Although NSSI has been drawing the attention of researchers intensely for the last 30 years, to date there is no published study about rates of NSSI behaviors in countries of south-eastern Europe. The study aimed to explore NSSI in the Republic of Serbia. Data were collected using multistage random sampling. The final sample consisted of 2792 participants (57.4% female) while the NSSI subsample consisted of 405 participants (54.3% males). Results showed the NSSI rate in Serbia is 4.3% based on a percentage of people who answered affirmatively to lifetime NSSI engagement. However, when the percentage of people who reported at least one positive answer through the NSSI behaviors checklist, the rate rises to 14.5%. The most frequent NSSI behavior is wound picking. NSSI rate drops to 8.8% when wound picking is excluded. Those engaged in NSSI were more likely to report suicide attempts and seek professional help than those who did not report NSSI. Gender differences in NSSI frequency are found only in cases of headbanging and burning oneself. This study showed the scope of NSSI-related problems is similar in Serbia compared to other countries. It also raised questions about the lack of preventive programs and treatment strategies for dealing with NSSI in Serbia.[https://www.sciencedirect.com/science/article/pii/S2772598722000320]Corresponding author. Institute for Educational Research, Dobrinjska 11/3, 11 000, Belgrade, Serbia. E-mail addresses: [email protected], [email protected] (A. Radanović)

Determination of candesartan in human plasma with liquid chromatography - tandem mass spectrometry

A sensitive, specific and rapid liquid chromatography - tandem mass spectrometry method was developed and validated for the determination of candesartan in human plasma. Analyte was separated from endogenous components present in plasma by solid phase extraction. Chromatographic separation was performed on Gemini C18 analytical column using mobile phase acetonitrile – 5 mM ammonium formate pH 2 (90:10, v/v) at flow rate of 0.3 mL/min. For detection, tandem mass spectrometry in SRM mode with positive electrospray ionization was used. The mass transitions m/z 441.1 > 263.1 and 445.1 > 267.1 were used to determine candesartan by using candesartan-d4 as an internal standard. After development, the method was validated according to the requirements of EMA regulatory guidelines in the concentration range 1 - 400 ng/ml in human plasma. Limit of quantification (LLOQ) was 1 ng/ml. The developed and validated method proved to be very fast and reproducible and was therefore successfully implemented in pharmacokinetic and bioequivalence studies with large number of study samples.Za določevanje kandesartana v humani plazmi smo razvili in validirali LC-MS/MS metodo in dokazali, da je selektivna, občutljiva in ponovljiva. Za pripravo plazemskih vzorcev smo uporabili ekstrakcijo na trdni fazi. Za kromatografsko separacijo smo uporabili kolono Gemini C18 z mobilno fazo acetonitril – 5 mM amonijev formiat (90:10, v/v) pri pretoku 0,3 ml/min. Za detekcijo smo uporabili tandemsko masno spektrometrijo v SRM načinu z uporabo pozitivne ionizacije z elektro razprševanjem. Uporabljeni so bili masni prehodi: za kandesartan m/z 443,1 > 263,1 in za kandesartan-d4 kot interni standard 445,5 > 267,1. Po končanem razvoju smo metodo validirali v koncentracijskem območju 1–400 ng/ml v vzorcih humane plazme. Spodnja meja kvantitativne določitve je bila 1 ng/ml. Razvita in validirana metoda se je izkazala za zelo učinkovito pri farmakokinetičnih študijah

The conductivity measurements applied for the evaluation of controlled release of chlorhexidine from thermosensitive N-isopropylacrylamide derivative microgels

The aim of the work was the evaluation of the conductivity changes in aqueous environment, consisting of chlorhexidine, and N-isopropylacrylamide derivative microgel, during increasing the temperature between 25°C and 42°C, as a prerequisite to develop the this microgel for controlled release of chlorhexidine, when alterations in temperature are involved. Conductivity of studied systems underwent specific alterations, when temperature increased. For the system with polymer PNM I the values of conductivity were in the range 104,47 S/cm - 134,70 S/cm, for temperature range 25°C and 42°C. In the case of PNM II - CX system, respective values reached 91,75 S/cm - 135,95 S/cm. The lowest conductivity values were observed when PNM III - CX mixture was studied: 96,90 S/cm and 117,37 S/cm. When a complex of derivatives of N-isopropylacrylamide with chlorhexidine undergoes thermal alteration, there is a potential to obtain controlled release of chlorhexidine from the polymeric bead in the range between 25°C and 42°C. The affinity of chlorhexidine to the polymer may be assessed in this systems applying the conductivity measurements. The solubility of chlorhexidine in the polymeric systems should be in future evaluated, to determine role of this factor in the conductivity alterations

The use of conductometric assessments for development of pulsed release of lidocaine hydrochloride from thermosensitive N-isopropylacrylamide microgels

The aim of present work was preliminary assessment of the conductivity changes in aqueous compartment, consisting of lidocaine hydrochloride, and N-isopropylacrylamide derivative microgel, during increasing the temperature between 25° and 42°C, as a prerequisite to demonstrate the possibility of applying this microgel for pulsed release of lidocaine hydrochloride, when increased temperature is applied. Conductivity of respective systems composed of polymer and lidocaine hydrochloride were assigned as PNM I-LD, PNM II-LD, and PNM III - LD: obtained values were in the ranges: 39,91 muS/cm - 53,30 muS/cm in the 25°C temperature, 46,14 muS/cm - 56,16 muS/cm in the temperature of 32°C, and 53,30 muS/cm - 118,42 muS/cm at 42°C. During heating or cooling of the microgels derivatives of N-isopropylacrylamide, there is possibility to obtain pulsed release of lidocaine hydrochloride from the polymeric bead in the range between 25°C and 42°C, according to the conductivity measurements

Effect of ionic and non-ionic polymer on the pH of lidocaine hydrochloride preparation assessed below and over human skin surface temperature

Lidocaine is widely accepted local anesthetic, which is applied in the form of freely soluble hydrochloride salt. In this study we evaluated the pH of respective solutions of lidocaine hydrochloride with ionic polymer - polyacrylic acid or non-ionic polymer - methylcellulose, and compared to physiological skin conditions in the range between 22°C and 41°C. In microscopic observation of lidocaine hydrochloride preparations with polyacrylic acid the micro-sedimentation was revealed, however obtained mixture was opalescent, and homogenously dispersed in aqueous environment. The pH was maintained on the level not higher then 4,0 in the period of 12 hours for polyacrylic acid formulation, whereas in the case of preparation with methylcellulose, the pH increased from acceptable pH of ca. 4,5 to the level of above 6,0. The polyacrylic acid derivatives should be further studiedas vehicles forming preparations with stable pH value during application on the skin, with more specific methods including pH microelectrodes, sufficient for assessments in small quantities of liquids of skin surface