scholarly journals Anisotropic microparticles for differential drug release in nerve block anesthesia

RSC Advances ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 4623-4630
Author(s):  
Shivakumar B. S ◽  
Vignesh Gopalakrishnan-Prema ◽  
Gayathri Raju ◽  
Sumi E. Mathew ◽  
Neeraj Katiyar ◽  
...  

Stretch-induced anisotropy in bupivacaine-loaded PLGA micro particles (BMPs) induced stronger nerve blocks compared to spherical particles.

2021 ◽  
Author(s):  
Maryam Habibi ◽  
Mohsen Heidary ◽  
Mohammad Mehdi Tavakol ◽  
Goodarz Ahmadi

Abstract In this study, the dispersion and deposition of particles in the respiratory system attached to a mannequin lying down inside a room were investigated numerically. The respiratory system model was prepared by processing the CT scan images of a volunteer and was attached to a mannequin lying in the middle of a room. The flow field around the mannequin and effects of the thermal plume on the particle aspiration by the mannequin model was simulated using the Ansys-Fluent software. The aspiration efficiency of spherical particles in the airway was studied with the Lagrangian particle trajectory analysis, including the turbulence dispersion effects. For validation of numerical simulations, the aspiration efficiency of the particles obtained from the numerical solution was compared with the case of a standing mannequin. The results are presented for two different modes with upward and downward thermal plumes. For the first mode, due to the strong effect of the thermal plume in the upward direction, the aspiration efficiency of midrange particles increases. However, the aspiration efficiency of large micro-particles decreases for the first mode. For the second mode, with the downward thermal plume, the aspiration efficiency of small micro-particles increases significantly.


2021 ◽  
pp. rapm-2021-102472
Author(s):  
Daniel Gessner ◽  
Oluwatobi O Hunter ◽  
Alex Kou ◽  
Edward R Mariano

BackgroundRoutine follow-up of patients who receive a nerve block for ambulatory surgery typically consists of a phone call from a regional anesthesia clinician. This process can be burdensome for both patients and clinicians but is necessary to assess the efficacy and complication rate of nerve blocks.MethodsWe present our experience developing an automated system for completing follow-up via short message service text messaging and our preliminary results using it at three clinical sites. The system is built on REDCap, a secure online research data capture platform developed by Vanderbilt University and currently available worldwide.ResultsOur automated system queried patients who received a variety of nerve block techniques, assessed patient-reported nerve block duration, and surveyed patients for potential complications. Patient response rate to text messaging averaged 91% (higher than our rates of daily phone contact reported previously) for patients aged 18 to 90 years.ConclusionsGiven the wide availability of REDCap, we believe this automated text messaging system can be implemented in a variety of health systems at low cost with minimal technical expertise and will improve both the consistency of patient follow-up and the service efficiency of regional anesthesia practices.


1986 ◽  
Vol 11 (1) ◽  
pp. 115-116
Author(s):  
N. J. PERCIVAL

Axillary nerve blocks are now frequently used for emergency and elective upper limb surgery. The method gives reliable anaesthesia with few complications. A case is described in which a patient developed Herpes Zoster following an Axillary Nerve Block, a hitherto unreported complication.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Viktoria Schreiner ◽  
Mattea Durst ◽  
Margarete Arras ◽  
Pascal Detampel ◽  
Paulin Jirkof ◽  
...  

Abstract Buprenorphine is a frequently used analgetic agent in veterinary medicine. A major drawback, however, is the short duration of action requiring several daily administrations. We therefore designed a poly-lactic-co-glycolic acid (PLGA) based microparticulate drug formulation for sustained parenteral drug release. Particles were designed to allow for a fast onset of action and a duration of the analgesic effect of at least two days in laboratory mice. Microparticles were produced using a solvent evaporation technique. Release rate was dependent on polymer type and particle size. Spherical particles used for subsequent animal studies had a mean size of 50 µm and contained 4.5% of buprenorphine. Drug release was characterized by an initial burst release of 30% followed by complete release over seven days. In vivo pharmacokinetic experiments in female C57BL/6 J mice confirmed prolonged exposure in plasma and brain tissue and correlated with the pharmacological effect in the hot plate assay or after minor abdominal surgery. No adverse side effects with respect to food and water intake, body weight, local tolerability, or nesting behavior were observed. Our formulation is an attractive alternative to established immediate release formulations. A use for prolonged pain management in laboratory animals is proposed.


2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Parviz Amri ◽  
Novin Nikbakhsh ◽  
Seyed Reza Modaress ◽  
Ramin Nosrati

Background: Rigid bronchoscopy is often used to diagnose and treat the location of resection of the tracheal stenosis. It is a selective procedure for the dilatation of tracheal stenosis, especially when accompanied by respiratory distress. Objectives: We introduced patients who were diagnosed with tracheal stenosis and candidate for rigid bronchoscopy dilatation by the upper airway nerve blocks. Methods: This prospective observational study was conducted on 17 patients who underwent dilatation with rigid bronchoscopy in tracheal stenosis at Hospitals affiliated with Babol University of Medical Sciences from 2002 to 2017. The patients were given three nerve blocks, 6 bilateral superior laryngeal nerve block, bilateral glossopharyngeal nerve block, and recurrent laryngeal nerve block (transtracheal) before awake rigid bronchoscopy using 2% lidocaine. We evaluated the demographic data, the cause of tracheal stenosis, the quality of the airway nerve block (Intubation score), patients’ satisfaction from bronchoscopy and thoracic surgeons’ satisfaction. Complications of nerve blocks were recorded. Results: From 2002 to 2017, 17 patients (14 were male and 3 were) female with tracheal stenosis who were candidates for dilatation with bronchoscopy and accepted the upper nerve block were included. The quality of the block was acceptable in 16 (94%) patients. 15 patients received fentanyl, and only two patients did not need to intravenous sedation. The mean age of patients was 29.59 ± 11.59. The average satisfaction of the surgeon was 8.82 ± 1.13 and the satisfaction of patients with anesthesia was 8.89 ± 1.16. There was one serious complication (laryngospasm) in one patient. Conclusions: The upper airway nerve block method is a suitable anesthesia technique for patients with tracheal stenosis who are candidates for the tracheal dilatation with rigid bronoscopy, especially when the patient has respiratory distress and has not been evaluated before surgery.


2019 ◽  
Vol 4 (3) ◽  
pp. 1-6
Author(s):  
Farzin Sahebjam

Background : To compare the duration of action of a local anesthetic block using a lipid formulation of bupivacaine to the commercially available aqueous formulation. Bupivacaine 0.5% was mixed with an equal volume of either lipid emulsion (Intralipid, Fresenius Kabi) or normal saline resulting in a final concentration of 0.25% bupivacaine. Eighteen sheep were administered a n erve block of either control or treatment at the metacarpal region of each forelimb to compare the efficacy of the injected formulations. The nociceptive test was determined by applying a blunt noxious stimulus to the foot below the nerve block at multiple time intervals until the sheep responded by withdrawing its foot. The person assessing the response to the noxious stimulus was blinded to the treatment. Results: The Intralipid formulation significantly extended the duration of the nerve block compared to the control group. The mean analgesic period (mean±SD) in the control legs was 4.23±1.8 hr. compared to 5.81±1.78 hr. in the Intralipid injected legs (p=0.013). Conclusions : In conclusion, an Intralipid® - based formulation provided a more prolonged dura tion of local anesthesia after nerve blocks in the sheep metacarpal region compared to aqueous bupivacaine.


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