Infusion System (infusion + system)

Distribution by Scientific Domains


Selected Abstracts


Patient-controlled Analgesia in Intrathecal Therapy for Chronic Pain: Safety and Effective Operation of the Model 8831 Personal Therapy Manager with a Pre-implanted SynchroMed Infusion System

NEUROMODULATION, Issue 3 2003
Jan Maeyaert
Abstract The Model 8831 Personal Therapy Manager (PTM) offers a patient-controlled analgesia (PCA) option for the SynchroMed Infusion System (Medtronic Inc., Minneapolis, MN). The safety and effective operation of the PTM activator was evaluated in 45 patients in five European centers receiving intrathecal drug infusion for the treatment of chronic pain via a SynchroMed pump. The total volume of drug delivered intrathecally over a four-week follow-up period was calculated. Adverse events were recorded and pain levels were measured via the Visual Analog pain Scale (VAS), Brief Pain Inventory, and SF-12 Quality of Life scores. Patient satisfaction with the device and its instruction manual was also assessed by questionnaire. The expected and calculated intrathecal drug volumes (and therefore drug doses) were the same, demonstrating that the device worked as intended. There were no device-related serious adverse events. Overall, 96% of patients were satisfied with the activator. Patients appreciated being able to control their pain and considered the device and its instructions easy to use. The PTM was shown to be safe and functioning properly in the intrathecal treatment of pain. The successful addition of a PCA function to the SynchroMed system may create a new standard in intrathecal pain therapy. [source]


Indirect evidence for increased mechanosensitivity of jejunal secretomotor neurones in patients with idiopathic bile acid malabsorption

ACTA PHYSIOLOGICA, Issue 2 2009
A. Bajor
Abstract Aim:, The interdigestive motor rhythm, the migrating motor complex (MMC), is accompanied by active secretion of chloride during periods of distally propagating maximal motor activity (MMC phase III). We studied the behaviour of this system in bile acid malabsorption (BAM), a relative common cause of chronic diarrhoea. We measured motor activity and transmucosal potential difference (PD, reflecting active chloride secretion), in the proximal jejunum in healthy controls (n = 18) and in a group of patients with BAM (n = 11). The phase III-generated voltage was related to the degree of BAM quantified by the 75SeHCAT test. Methods:, We used a multi-channel intestinal infusion system to simultaneously measure jejunal pressure and PD. Saline passing calomel half-cells was infused into the jejunum and subcutaneously. Pressure and PD were recorded in the fasting state and after a test meal. Results:, In the absence of motor activity, jejunal PD was not significantly different from zero in either group. During MMC phase III, PD reached significantly higher mean and peak levels in BAM patients. The product of MMC phase III length multiplied by voltage, over 3 h, was also significantly higher in BAM patients (controls: median 307 mV × cm, range 70,398; BAM: median 511, range 274,2271, P < 0.01). This value was also significantly correlated with the degree of BAM as reflected by the 75SeHCAT test (P < 0.05). Conclusion:, Phase III induced jejunal secretion may be upregulated in BAM patients, resulting in overload of colonic reabsorption capacity. [source]


Effects of Arg-Gly-Asp Sequence Peptide and Hyperosmolarity on the Permeability of Interstitial Matrix and Fenestrated Endothelium in Joints

MICROCIRCULATION, Issue 6 2004
A. POLI
ABSTRACT Objectives: The aims were to assess the contribution of arg-gly-asp (RGD) mediated cell integrin,matrix bonds to interstitial hydraulic resistance and to fenestrated endothelial permeability in joints. Joint fluid is generated by filtration from fenestrated capillaries and drains through a fibronectin-rich synovial intercellular matrix. The role of parenchymal cell,matrix bonding in determining tissue hydraulic resistance is unknown. Methods: The knee cavity of anesthetized rabbits was infused with saline or the competitive hexapeptide blocker GRGDTP, with or without added osmotic stress (600 mosm saline). Intra-articular pressure Pj, net trans-synovial drainage rate s, and the permeation of Evans blue-labeled albumin (EVA) from plasma into the joint cavity were measured. Results: GRGDTP increased the hydraulic conductance of the synovial drainage pathway, ds/dPj, by 71% (p = .02, paired t test, n = 6 animals). Synovial plasma EVA clearance (control 7.1 ± 0.8 ,L h,1, mean ± SEM, n = 15) was unaffected by GRGDTP (7.0 ± 2.3 ,L h,1, n = 6) or hyperosmolarity (4.9 ± 1.5 ,L h,1, n = 8) but was increased by GRGDTP and hyperosmolarity together (15.9 ± 4.8 ,L h,1, n = 5) (p = .01, ANOVA). Changes in dPj/dt evoked by GRGDTP plus hyperosmolarity, but neither alone, demonstrated increased microvascular filtration into the joint cavity (p < .001, ANOVA), as did changes in fluid absorption from the infusion system at fixed Pj. Conclusions: RGD-mediated bonds between the parenchymal cells and interstitial polymers reduce the interstitial hydraulic conductance by 42%. This helps to retain the lubricating fluid inside a joint cavity. RGD-mediated bonds also support the macromolecular barrier function of fenestrated endothelium, but in vivo this is evident only in stressed endothelium (cf. in vitro). [source]


Structural and mechanical remodelling of the common bile duct after obstruction

NEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2002
B. U. DUCH
Biliary obstruction in man, most often caused by cholelithiasis, induces remodelling of the bile ducts. Obstruction-induced structural remodelling of the common bile duct (CBD) has been previously described. The mechanical changes that accompany the structural remodelling, however, have not been studied in detail. The aim of this study is to quantify the structural and mechanical changes in the CBD at different time intervals after acute obstruction. The CBD was ligated in the pig, near the duodenum, and studied after 3 h, 12 h, 2 days, 8 days and 32 days (n=5 in each group). One additional animal in each group was sham-operated. At each scheduled time, the CBD was mechanically tested in vitro with a computer-controlled volume infusion system to study the pressure,volume relationship of the CBD segment. A video camera provided simultaneous measurements of the outer dimensions of the CBD at the various pressures. The diameter and wall thickness of the CBD increased about three-fold in the 32-day group compared to the sham group (P < 0.001). The circumferential stress,strain relationship differed between groups (P < 0.001); it was shifted to the right, indicating softening, in the 3-h, 12-h, and 2-day groups and to the left, indicating stiffening, in the 8-day and 32-day group, compared to the sham group. The longitudinal stress,strain curves were all shifted to the left of the circumferential stress,strain curves (P < 0.05). The collagen area increased during obstruction (P < 0.001) but no correlation between the size of the collagen area and the biomechanical parameters was found. A practical implication of the present study serves as a warning to surgeons. A reduction in the wall stiffness in the first several days of obstruction along with an increased duct diameter and a decreased wall thickness suggest that operative procedures such as suturing, anastomosis and procedures related to ERCP must be performed with special care to avoid damage to the CBD. [source]


Safety and Efficacy of Intrathecal Baclofen Infusion by Implantable Pump for the Treatment of Severe Spinal Spasticity: A Spanish Multicenter Study

NEUROMODULATION, Issue 4 2000
J Vidal MD
Objective. To assess long-term efficacy, safety and functional benefit of intrathecal baclofen for severe spinal spasticity. Materials and Methods. This prospective multicenter study was performed in two stages: the first one consisted of an intrathecal bolus injection of baclofen, and the second of a continuous intrathecal baclofen infusion by means of an implantable pump. The sample consisted of 72 adult patients with severe spinal spasticity. Sixty-four were implanted and followed for 36 months. Muscular tone, spasms, and functional scales were evaluated before and periodically after administration of the drug, with a follow-up period of 36 months. Results. A very significant decrease in tone and spasms was observed in all cases (p < 0.001). Tolerance appeared during the first 12 months, increasing doses from a mean initial dose of 83.2 ,g (range 25,200 ,g) to a mean final dose of 270 ,g (range 25,800 ,g). Later on, efficacy remained stable, except in cases of mechanical problems of the infusion system. [source]


Quantitative screening and matrix effect studies of drug discovery compounds in monkey plasma using fast-gradient liquid chromatography/tandem mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 24 2001
Yunsheng Hsieh
A higher-throughput bioanalytical method based on fast-gradient (1,min run time) high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS) was developed for screen-type analyses of plasma samples from early drug discovery studies in support of exploratory pharmacodynamic studies. The HPLC system equipped with minibore column was interfaced with either atmospheric pressure chemical ionization (APCI) or electrospray (ESI) ionization techniques. The matrix ion suppression effect of both quantitative HPLC/MS/MS analyses was compared using the post-column infusion system. The use of the described methods provided advantages such as a shorter chromatographic region of ion suppression, less solvent consumption and shorter run times in comparison with standard analytical column HPLC/MS/MS methods. The analytical results obtained by both HPLC/MS/MS methods were in good agreement (within 15% of error) and displayed a good correlation with the pharmacodynamic outcome. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Stability and compatibility of drug mixtures in an implantable infusion system

ANAESTHESIA, Issue 9 2008
F. Bianchi
Summary This study evaluated the stability and the compatibility of mixtures of morphine sulphate, bupivacaine, and clonidine hydrochloride and of hydromorphone, bupivacaine, and clonidine hydrochloride, when used in constant flow implantable pumps under simulated clinical use conditions. The pumps were filled with drug mixtures and incubated at 37 °C for a period of 90 days. Aliquots were sampled monthly from the reservoir and catheter outlet and the drug concentrations analysed using validated chromatography methods. Individual materials from the infusion system were immersed in the drug mixtures and stored at 37 °C for 60 weeks and evaluated for mechanical performance for compatibility testing. Both drug mixtures were found to be stable over 90 days in the pump at 37 °C. All device materials retained acceptable mechanical performance following exposure. These results demonstrate that both drug mixtures are stable when maintained at simulated body temperature in an implantable infusion system for 90 days. [source]