Relationship Between the Loaded Pressure and Flow Rate of Packed Red Blood Cells and Various Infusion Solutions in Normal Infusion Lines and Catheters.

BACKGROUND: We investigated the relationship between the loaded pressure and flow rate in various catheters and the entire infusion line including the catheters, in several infusion solutions and packed red blood cells. METHODS: We connected the infusion line and catheter to the infusion solution and used an outer pressure bag or a compressor to pressurize the infusion solution bag to a pressure within the clinical (up to 450 mm Hg) or higher range (up to 1050 mm Hg). We approximated the relationship between the loaded pressure and flow rate in the entire infusion line including the catheter, versus the catheter alone, as a power function and compared the power numbers. RESULTS: In the clinical pressure range of normal saline, the power numbers of the entire infusion line for the 24-, 22-, 20-, and 18-gauge catheters were 0.76, 0.82, 0.81, and 0.86, respectively, while those for the catheter alone were 0.67, 0.63, 0.56, and 0.44, respectively. In the higher pressure range of normal saline, the power numbers of the entire infusion line for the 24-, 22-, 20-, and 18-gauge catheters were 0.68, 0.70, 0.71, and 0.73, respectively, while those for the catheter alone were 0.62, 0.61, 0.59, and 0.58, respectively. As the power number of the entire infusion line was closer to 1.00 than the values of the catheter, the relation between the loaded pressure and the flow rate was more linear in the entire infusion line than that in the catheter. Similar results were obtained using packed red blood cells and 40% glycerin mixture in normal saline. CONCLUSIONS: Regardless of the type of infusion solution or transfusion, the pressure-flow relationship in the catheter was nonlinear and not directly proportional. However, within the clinical pressure range (up to 450 mm Hg), the relationship between the flow rate and pressure in the entire infusion line was almost linear and proportional.

Assessment of efficacy of postinfusion tubing flushing in reducing risk of cytotoxic contamination.

PURPOSE: Infusion of cytotoxic drugs carries the risk of occupational exposure of healthcare workers. Since disconnecting an infusion line is a source of contamination, flushing of tubing after infusion of cytotoxic agents is recommended, but the optimal volume of rinsing solution is unknown. The objective of this study was to assess whether postinfusion line flushing completely eliminates cytotoxics. METHODS: Infusions were simulated with 3 cytotoxics (gemcitabine, cytarabine, and paclitaxel) diluted in 5% dextrose injection or 0.9% sodium chloride injection in 250-mL infusion bags. Infusion lines were flushed using 5% dextrose injection or 0.9% sodium chloride solution at 2 different flow rates. The remaining concentration of cytotoxics in the infusion line was measured by a validated high-performance liquid chromatography (HPLC) method after passage of every 10 mL of flushing volume until a total of 100 mL had been flushed through. RESULTS: All cytotoxics remained detectable even after line flushing with 80 mL of flushing solution (a volume 3-fold greater than the dead space volume within the infusion set). Gemcitabine and cytarabine were still quantifiable via HPLC even after flushing with 100 mL of solution. Efficacy of flushing was influenced by the lipophilicity of drugs but not by either the flushing solvent used or the flushing flow rate. After 2-fold dead space volume flushing, the estimated amount of drug remaining in the infusion set was within 0.19% to 0.56% of the prescribed dose for all 3 cytotoxics evaluated. CONCLUSION: Complete elimination of cytotoxics from an infusion line is an unrealistic objective. Two-fold dead space volume flushing could be considered optimal in terms of administered dose but not from an environmental contamination point of view. Even when flushed, the infusion set should still be considered a source of cytotoxic contamination.

[Perioperative infusion therapy in children : Are infusion sets with precision flow regulators suitable for pediatric anesthesia?] / Perioperative Infusionstherapie im Kindesalter : Eignen sich Infusionssysteme mit Laufratenbeschränkung für die Kinderanästhesie?

BACKGROUND: Infusion sets with precision flow regulators are frequently used in children undergoing surgery in order to control the perioperative administration of fluids. There are no data about the safety and accuracy of these infusion sets. A study was therefore conducted to compare adjusted and actual flow rates of three different infusion sets with precision flow regulators under standardized conditions. METHODS: The study evaluated three different infusion sets with precision flow regulators each at two different static levels. The actual flow rates of 5 infusions were recorded each time for adjusted flow rates of 50 ml/h, 100 ml/h, 150 ml/h, 200 ml/h and 250 ml/h over 1 h. Statistical analysis was performed with Excel (Excel, Microsoft Corporation, Redmond, WA, USA) and SOFA (Paton-Simpson and Associates Ltd., USA). The results are presented as means (standard deviation). RESULTS: For the adjusted flow rates of 50, 100, 150, 200 and 250 ml/h, actual flow rates were 107 (5.3), 174.8 (6.5), 255.8 (10.2), 312.4 (15.7) and 362.6 (20.2) ml/h for the Frekadrop® infusion set at a static level of 128 cm and 83.8 (4.4), 147.8 (5.5), 197 (12.4), 257.2 (4.97) and 311.6 (17.9) ml/h at a static level of 100 cm, respectively. For the Exadrop® infusion set actual flow rates were 88.6 (6.9), 131.2 (14.1), 224.4 (14.1), 296.6 (27.6) and 330.4 (22.4) ml/h at a static level of 128 cm and 54 (4), 82.4 (10.2), 138.8 (15.7), 209.4 (36.8) and 249 (12) ml/h at a static level of 76 cm, respectively. For the D-Flo infusion set actual flow rates were 95.6 (2.8), 167.6 (29), 217.8 (9.9), 281.6 (10.6) and 396.8 (37.5) ml/h at a static level of 128 cm and 69.2 (4.4), 110.2 (12.6), 169.2 (6), 205.2 (14) and 243 (15.9) ml/h at a static level of 80 cm, respectively. CONCLUSION: The actual flow rates differed considerably from the adjusted flow rates in the evaluated infusion sets. The flow rates substantially depended on the static level of the infusion. First and foremost, regulation of the administered infusion volume does not seem to be reliable when using an infusion set with a precision flow regulator.

Programmed intermittent bolus infusion versus continuous infusion of 0.2% levobupivacaine after ultrasound-guided thoracic paravertebral block for video-assisted thoracoscopic surgery: A randomised controlled trial.

BACKGROUND: The analgesic benefits of programmed intermittent bolus infusion for thoracic paravertebral block remain unknown. OBJECTIVE: The aim of this study was to compare the analgesia from intermittent bolus infusion with that of a continuous infusion after thoracic paravertebral block. DESIGN: A randomised controlled study. SETTING: A single centre between December 2016 and November 2017. Seventy patients scheduled for video-assisted thoracoscopic surgery were included in the study. INTERVENTION(S): Patients were randomly assigned to receive 0.2% levobupivacaine via continuous infusion (5 ml h, continuous group) or programmed intermittent bolus infusion (15 ml every 3 h, bolus group) after an initial 15-ml bolus injection of 0.2% levobupivacaine. MAIN OUTCOME MEASURES: The main outcome was the amount of rescue fentanyl (per kg of body weight) consumed within 24 h after surgery. Secondary outcomes were postoperative pain scores, plasma levobupivacaine concentrations and the number of dermatomes anaesthetised. RESULTS: There was no significant difference between the continuous and bolus groups in the postoperative consumption of fentanyl (median [interquartile range] 5.5 [4 to 9.5] µg kg versus 6 [3.5 to 9] µg kg respectively, P = 0.45) and postoperative pain scores within 24 h. At 20 h after initiating the infusions, there was no statistically significant difference between the two groups in terms of the plasma levobupivacaine concentration. The number of dermatomes anaesthetised to pinprick and cold testing was significantly greater in the bolus group. CONCLUSION: Our findings suggest that postoperative pain and opioid usage are similar with either programmed intermittent bolus infusion or continuous infusion after thoracic paravertebral block. Programmed intermittent bolus infusion provides a wider sensory blockade and could benefit patients requiring a wider extent of anaesthesia. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR; URL: http://umin.ac.jp/ctr/, ID: UMIN000023378).

American Society for Parenteral and Enteral Nutrition Guidelines for the Selection and Care of Central Venous Access Devices for Adult Home Parenteral Nutrition Administration.

This document represents the American Society for Parenteral and Enteral Nutrition (ASPEN) clinical guidelines to describe best practices in the selection and care of central venous access devices (CVADs) for the infusion of home parenteral nutrition (HPN) admixtures in adult patients. The guidelines targeted adults >18 years of age in which the intervention or exposure had to include HPN that was administered via a CVAD. Case studies, non-English studies, or studies of CVAD no longer available in the United States were excluded. In total, 564 abstract citations, 350 from Medline and 214 from PubMed/non-MEDLINE databases, were scanned for relevance. Of the 564 citations, 13 studies addressed at least 1 of the 6 guideline-related questions, and none of the studies were prospective and randomized. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria were used to adjust the evidence grade based on assessment of the quality of study design and execution. Recommendations for the CVAD type, composition, or number of lumens to minimize infectious or mechanical complications are based on a limited number of studies and expert opinion of the authors, all very experienced in home infusion therapy. No studies were found that compared best solutions for routine flushing of lumens (eg, heparin versus saline) or for maintaining catheters in situ while treating CVAD mechanical or infectious complications. It is clear that studies to answer these questions are very limited, and further research is needed. These clinical guidelines were approved by the ASPEN Board of Directors.

Twenty-five-gauge trocar anterior chamber maintainer: New device for infusion.

The technique, feasibility, and results of a new 25-gauge trocar-anterior chamber maintainer (ACM) designed for maintaining intraoperative fluid infusion is described in this prospective interventional analysis. The 25-gauge trocar-ACM with an overall length of the trocar blade of 6.0 mm, cannula length of 4.0 mm, and the cannula tip beveled at 45 degrees to the base was designed and used in all the cases. The dimensions of the sclerotomy wound that comprised of the internal ostium, external ostium, wound length, and the time interval for wound apposition in the postoperative period was analyzed by spectral-domain anterior segment optical coherence tomography.

Selección de emulsiones lipídicas en nutrición parenteral: parámetros bioquímicos y hematológicos / Lipid emulsion selection in parenteral nutrition. Biochemical and hematological paramaters

Introducción: el patrón de ácidos grasos (AG) de las emulsiones lipídicas (EL) utilizadas en nutrición parenteral (NP) condiciona diferentes respuestas fisiológicas. Objetivos: estudiar si los criterios clínicos de prescripción de EL en NP establecidos en nuestro protocolo abierto y basados en recomendaciones se correlacionan con marcadores bioquímicos y hematológicos iniciales. Métodos: estudio observacional retrospectivo de cuatro años. Se recogieron variables demográficas, clínicas, nutricionales y analíticas al inicio de la NP. Se realizó un análisis uni y multivariante para estudiar la asociación entre los valores iniciales de los parámetros bioquímicos y hematológicos (PBHE) y el tipo de emulsión lipídica empleada. Resultados: de los 1.558 pacientes, 460 pacientes (29,5%) tenían PBHE al inicio de la NP y utilizaron mayoritariamente las combinaciones soja (AS) + triglicéridos de cadena media (MCT) + oliva (AO) + pescado (AP) (37,4%) y AS+MCT+AO (35,6%). Se encontraron diferencias estadísticamente significativas en el patrón EL utilizado entre los pacientes con y sin PBHE: patrón de AG con AP 44,8% vs. 39,5%, respectivamente. Las situaciones clínicas con proteína C-reactiva (PCR) elevada se asociaron con mayor uso de EL con AP: AS+AO+AP (OR: 4,52 [IC 95%: 1,43-13,91] y AS+MCT+AO+AP (OR: 3,34 [IC 95%: 2,10-5,33]). En situaciones clínicas complejas asociadas con paciente crítico se utilizó EL con MCT: afectación hepática (AS+MCT OR: 2,42 [IC 95%: 1,03-5,68]) y afectación renal (AS+MCT+AP OR: 3,34 [IC 95%: 1,12-9,99]). Conclusiones: la inclusión protocolizada de PBHE al inicio de la NP permite complementar criterios clínicos y metabólicos en la elección de la EL (AU)

Introduction: Lipid emulsions (LE) are a component of parenteral nutrition (PN) and its fatty acid (FA) profile determines various physiological responses. Objectives: To assess the adequacy of a clinical not restricted protocol in the choice of LE by studying complementary biochemical and hematological parameters (BHP) at the beginning of the PN. Methods: A 4-year retrospective observational study of LE administered to patients with PN. Demographic, clinical, nutritional and analytical variables at the beginning of the PN were collected. Univariate and multivariate analyses were performed to study the correlation between the initial clinical and biochemical parameters and the LE profile used. Results: Four hundred and sixty patients (29.5%) out of 1,558 had BHP at the beginning of PN and used mainly the LE combinations soybean (SO) + medium-chain triglycerides (MCT) + olive (OO) + fi sh (FO) (37.4%) and SO + MCT + OO (35.6%). Statistically significant differences on the LE pattern were observed between patients with and those without initial BHP (44.8% vs 39.5% received FO, respectively). Conditions regularly associated with elevated C-reactive protein (CRP) were associated with increased use of FO LE: SO+OO+FO (OR: 4.52 [95% CI: 1.43-13.91]) and SO+MCT+OO+FO (OR: 3.34 [95% CI: 2.10-5.33]). In those complex conditions related with the critical patient MCT were used: hepatic failure (SO+MCT OR: 2.42 [95% CI: 1.03-5.68]) and renal failure (SO+MCT+FO OR: 3.34 [95% CI: 1.12-9.99]). Conclusions: The use of BHP at the beginning of PN treatment allows complementing the clinical and metabolic criteria in LE selection (AU)

Safe practice in syringe pump management.

Syringe pumps offer an alternative route for delivering medicine when the oral route cannot be used. This is particularly important for patients receiving palliative care, for whom a continuous infusion of medication can improve symptom control. This article explains how to administer drugs safely using these devices.

In vitro toxicity of infusion sets depends on their composition, storage time and storage conditions.

Disposable medical devices release toxic leachables during their clinical use. Specifically, the individual parts of the infusion sets (the drip chamber, tube, flashball and injection site) are composed of numerous chemical compounds that can reach the patients' systemic circulation and induce local and systemic toxic effects. We aimed to reveal the relative in vitro toxicity of infusion sets from the leading vendors that are used in Israel, and to determine its dependence on their design and storage time/conditions. We found that leachates of the rubber parts were more toxic than those of the other parts of the infusion sets. The measured toxicity was affected by the experimental settings: the cells, medium composition, exposure duration, and the type of assay applied for toxicity assessment. We recommend to use the capillary endothelium cells for in vitro toxicity testing of the infusion sets, and refrain from the use of the MTT test which is insufficiently reliable, and can lead to artefacts and incorrect conclusions. Further investigation is needed to identify the toxic leachables from the individual parts of the infusion sets, and to reveal the risk of their toxicity during the clinical use of the infusion sets.

Compatibility of medications during multi-infusion therapy: A controlled in vitro study on a multilumen infusion device.

OBJECTIVE: Drug incompatibilities can jeopardize the safety and effectiveness of intravenous drug therapies, especially in the field of anaesthesia and intensive care. Patients receive many drugs simultaneously through limited venous accesses. This study was designed to confirm the impact of a multilumen infusion device on the occurrence of known physical drug incompatibilities. STUDY DESIGN: In vitro laboratory work. METHODS: Two infusion devices were studied: a standard single-lumen set and a multilumen infusion access device (Edelvaiss Multiline-8, Doran International). Up to six drugs were infused simultaneously: three acidic solutions of midazolam, amiodarone and dobutamine, and three alkaline solutions of furosemide, pantoprazole and amoxicillin/clavulanate. Saline, Ringer' solution and 5% dextrose were used as hydration vehicles with an infusion rate initially set at 100 mL/h and with stepwise decreases of 10 mL/h until precipitation. Two methods were used to highlight physical drug compatibility according to the European Pharmacopoeia: visual inspection of the extension set and an obscured-light sub-visible particle count test of infusions. The lowest infusion rate value for vehicle infusion to satisfy the two tests in all trials is reported for each infusion device. RESULTS: The standard set did not satisfy the test in 82% of the assessed drug combinations. The Edelvaiss Multiline-8 was able to prevent the occurrence of drug incompatibilities in 49% of the drug combinations tested. This device is therefore advantageous, especially when simultaneously infusing two or four incompatible drugs. CONCLUSIONS: Infusion device characteristics have an impact on physical drug incompatibilities. Our results confirm that the Edelvaiss Multiline-8 device prevents physical drug incompatibilities under specified conditions.

Interventional MRI-guided local delivery of agents into swine bile duct walls using MR-compatible needle-integrated balloon catheter system.

The purpose of this study was to investigate the feasibility of interventional MRI-guided local agent delivery into pig common bile duct (CBD) walls using a newly designed MR-compatible, needle-integrated balloon catheter system. We first designed a needle-integrated balloon catheter system that comprised of a 22 G MR-compatible Chiba biopsy needle and a conventional 12 mm × 2 cm balloon catheter. Under fluoroscopy guidance, a custom needle-balloon system was positioned in the target CBD via a transcholecystic access. T1-weighted MRI was used to localize and reposition the needle-balloon system in the target. A 0.5 mL mixture of motexafin gadolinium (MGd) and trypan blue dye as well as 5-fluorouracil was delivered into the CBD wall through the needle-balloon system. Post-infusion T1-weighted MRI was obtained and contrast-to-noise ratios (CNRs) of CBD walls of pre- and post-MGd-blue infusions were compared by a paired t-test. In addition, post-infusion x-ray cholangiography was achieved to evaluate the potential injuries of CBDs by the needle-balloon system. Subsequent histologic analysis was performed to correlate and confirm the imaging findings. A post-infusion cholangiogram did not show any extravasation of contrast agent, indicating no procedure-related damage to the CBDs. MRI demonstrated clear enhancement of the target bile duct walls infused with MGd-trypan blue dye with average penetration depth of 4.7 ± 1.2 mm and an average MGd perfusion length of 21 ± 1.5 mm in the bile ducts and their surrounding tissues. The average CNR of the post-infusion bile ducts was significant higher than that of the pre-infusion bile ducts (110.6 ± 22 versus 5.7 ± 2.8, p < 0.0001). Histology depicted the blue dye staining and red fluorescence of MGd through the target CBD walls, which was well correlated with the imaging findings. It is feasible to use the new MR-compatible, needle-integrated balloon catheter system for intrabiliary local agent delivery into CBD walls under MRI guidance, which may open new avenues for efficient management of pancreatobiliary malignancies using MR-guided interventional oncology.

Migrability of PVC plasticizers from medical devices into a simulant of infused solutions.

Medical devices (MD) for infusion and artificial nutrition are essentially made of plasticized PVC. The plasticizers in the PVC matrix can leach out into the infused solutions and may enter into contact with the patients. In order to assess the risk of patient exposure to these plasticizers we evaluated the migration performance of DEHP, DEHT, DINCH, and TOTM using a model adapted to the clinical use of the MDs. Each PVC tubing sample was immersed in a simulant consisting of a mixture of ethanol/water (50/50v/v) at 40°C and migration tests were carried out after 24h, 72h, and 10 days.DEHP had the highest migration ability, which increased over time. The amount of TOTM released was more than 20 times less than that of DEHP, which makes it an interesting alternative. DEHT is also promising, with a migration level three times smaller than DEHP. However, the migration ability of DINCH was similar to DEHP, with the released amounts equaling 1/8th of the initial amount in the tubing after 24h of contact. Taking into account the available toxicological data, TOTM and DEHT appear to be of particular interest. However, these data should be supplemented and correlated with clinical and toxicological studies on plasticizers and their metabolites.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a case report.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is a complex procedure used for the treatment of various types of cancer. Specifically, HIPEC has shown success where treatment failure sites (metastases) thrive. A classic example of one such area is the peritoneal surface, which remains a prominent failure site for patients with gynecologic and gastrointestinal cancer. Traditionally, most patients with advanced stages of cancer have undergone palliative procedures as part of their treatment modality or had no surgery at all. With the advent of cytoreductive surgery with HIPEC, patients with peritoneal cancer have shown increased survival rates. Anesthetic complications are common during this procedure with disturbances in hemodynamics, coagulation, and respiratory gas exchange. A knowledge of what to anticipate anesthetically will guide the practitioner to achieve successful management during and after the case. In this case report, a 71-year-old woman was treated for stage Ill peritoneal and ovarian cancer by cytoreductive surgery with HIPEC.

[Development of smart infusion system].

The free care smart infusion system which has the function of liquid end alarm and automatic stopping has been designed. In addition, the system can send the alarm to the health care staff by Zigbee wireless network. Besides, the database of infusion information has been set up, it can be used for inquiry afterwards.

In vivo performance of a microfabricated catheter for intraparenchymal delivery.

BACKGROUND: Convection-enhanced delivery (CED) is currently the only effective clinical technique to deliver biological therapeutic agents that would otherwise not cross the blood-brain barrier. Despite the promise of CED, several technical problems have limited its effectiveness. NEW METHOD: Brain infusions into a large mammal (pig) were performed with a catheter that was fabricated using micro-electro-mechanical systems (MEMS) technology (Olbricht et al., 2010). The performance of the catheter was evaluated for infusions at increasing infusion rates. Magnetic resonance (MR) images were acquired in real time to examine the distribution of infused tracers in the parenchyma. RESULTS: Both backflow and the distribution of CED of infusates into a variety of cytoarchitectures in porcine brain were quantified. Concentration profiles were determined for several MR contrast reagents as well as a fluorescent dye that are the sizes of small molecules, therapeutic proteins and an adeno-associated virus (AAV). The reagents can serve as surrogates for assessing the convective distribution of active molecules. Infusion rates up to 20µL/min were attained without evidence of backflow along the catheter. COMPARISON WITH EXISTING METHODS: The device performed well in terms of both backflow and infusion, superior to that of many studies reported in the literature on other catheters. All infused molecules had comparable ratios of distribution to infusion volumes. CONCLUSIONS: The catheter described in this report appears able to target tissue structures with precision, deliver therapeutics at high infusion rates, and resist backflow that can compromise the efficacy of CED therapy. The technology allows development of "smart" catheters for future applications.