PRO AND CONTRA ON ADJUVANTS TO NEUROAXIAL ANESTHESIA AND PERIPHERAL NERVE BLOCKS.

Modern approach in surgical treatment and in managing acute and chronic pain is nowadays more and more based on the implementation of all possible techniques of regional anesthesia (RA). Local anesthetics (LA) are needed to achieve standard regional anesthesia. Local anesthetics are primarily characterized by time constraints and duration of action, and depending on the amount applied, adverse effects on the cardiac and central nervous system may occur. Adjuvants are drugs used together with LA due to their synergistic effect, i.e. they improve start latency and duration of sensory and motor blockade and enable reduction of cumulative dose of LA and reduction of adverse effects on cardiac and nervous system. Nowadays, there is a huge variety of drugs that can be administered in combination with LA, and they, in general, can be divided into opioid and non-opioid adjuvants. The administration of opioids in RA over an extended time period was accompanied by some negative characteristics as respiratory depression, nausea, vomiting. So, their usage is still under a special control. Due to the positive effects shown by drugs from non-opioid adjuvants group (e.g. adrenaline, alpha adrenergic agonists, steroids, magnesium, midazolam, ketamine etc.), indications for their administration broadened. However, there are still some restrains in clinical practice based on the fact that neurotoxicity and demonstration of neurological complications in regional anesthesia haven't been properly researched yet.

NEW CONCEPT OF FUSION TECHNICS IN REGIONAL ANESTHESIA.

The aim of this review article is to introduce a newer approach to multimodal anesthesia. In addition to the usual combination of epidural catheter and general anesthesia as standard techniques in surgical procedures accompanied by intense postoperative pain, we want to encourage reflection on the application of various regional techniques in equally complex surgical conditions. By simply modifying the standard neuraxial technique with a higher thoracic approach, excellent abdominal surgery can be performed to awake the patient. However, placement of an epidural catheter is not always possible due to technical difficulties or patient-related conditions that contraindicate its insertion. Trunk-level fascia blocks (PVB, ESPB, RLB) are simple, safe alternative to an epidural catheter because the transverse process, which is the target of ultrasound, is easily visualized and the injection site is away from neuroaxis, pleura, and large vascular structures. In addition, extensive craniocaudal diffusion of anesthetics allows wide coverage with a single injection. It has been confirmed that PVB, ESPB, RLB blocks act on visceral and somatic pain. Therefore, their ultrasound-guided use in laparoscopic and other abdominal surgeries may be useful. With a well-designed fusion of regional techniques in operations of the upper and lower abdomen, it is possible to achieve hemodynamically and respiratory stable anesthesia in an awake patient with reduced postoperative pain.

Extracellular Vesicles from Human Cerebrospinal Fluid Are Effectively Separated by Sepharose CL-6B-Comparison of Four Gravity-Flow Size Exclusion Chromatography Methods.

Extracellular vesicles (EVs) are a versatile group of cell-secreted membranous nanoparticles present in body fluids. They have an exceptional diagnostic potential due to their molecular content matching the originating cells and accessibility from body fluids. However, methods for EV isolation are still in development, with size exclusion chromatography (SEC) emerging as a preferred method. Here we compared four types of SEC to isolate EVs from the CSF of patients with severe traumatic brain injury. A pool of nine CSF samples was separated by SEC columns packed with Sepharose CL-6B, Sephacryl S-400 or Superose 6PG and a ready-to-use qEV10/70 nm column. A total of 46 fractions were collected and analysed by slot-blot followed by Ponceau staining. Immunodetection was performed for albumin, EV markers CD9, CD81, and lipoprotein markers ApoE and ApoAI. The size and concentration of nanoparticles in fractions were determined by tunable resistive pulse sensing and EVs were visualised by transmission electron microscopy. We show that all four SEC techniques enabled separation of CSF into nanoparticle- and free protein-enriched fractions. Sepharose CL-6B resulted in a significantly higher number of separated EVs while lipoproteins were eluted together with free proteins. Our data indicate that Sepharose CL-6B is suitable for isolation of EVs from CSF and their separation from lipoproteins.