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Target-controlled infusion (TCI) is a mature technology that enables the delivery of intravenous anaesthetics in the concentration domain. The accuracy of the pharmacologic models used by TCI systems is imperfect, especially regarding pharmacodynamic predictions. This shortcoming of TCI devices is not critical. That TCI systems produce steady-state effect-site concentrations at or near a specified target is a more important attribute than a high level of accuracy because anaesthesiologists titrate to a stable level of drug effect whatever the actual concentration is. In this sense, TCI functions as a 'gain switch'. Achieving a steady state is more important than perfect accuracy. [ABSTRACT FROM AUTHOR]

Ni Eochagain and colleagues report that programmed intermittent bolus and continuous infusion regimens in continuous erector spinae plane (ESP) block catheters produced similar quality of recovery (QoR-15) scores, pain scores, and use of rescue opioids after video-assisted thoracic surgery. This is a reassuring finding for practitioners without access to pumps with programmed intermittent bolus functionality. Nevertheless, it remains plausible that the benefit of one regimen over another might vary depending on the specific infusion parameters. There continues to be scope for research into optimising programmed intermittent bolus delivery and dosing regimens and identifying the most appropriate clinical applications for this mode of infusion. [ABSTRACT FROM AUTHOR]

A patient admitted for non-ST-elevation acute coronary syndrome showed an episode of ST-segment elevation on the monitor. These alterations were due to an artifact produced by the administration of a saline bolus through an infusion pump that disappeared at the end of the bolus. Our findings highlight that the interpretation of the electrocardiogram requires careful analysis and correlation with the clinical situation and with other physiological parameters. [ABSTRACT FROM AUTHOR]

Schematic of IV multi-infusion system used in the study. [Display omitted] Sick neonates with haemodynamic instability often require complex medication regimens, which may result in the connection of a catecholamine infusion distally. This increases the dead volume of the infusion system, extending the time to medication delivery. This study evaluated the effects of body weight, and infusion connection point on the delivery rate of two medications infused through a multi-infusion system at infusion rates suitable for extremely and very low birth weight (ELBW and VLBW) neonates. An infusion system consisting of six infusions was used to investigate time to delivery, drug concentration at time to delivery and quantity of adrenaline and dopamine administered by intravenous infusions at infusion rates suitable for premature neonates. In an ELBW neonate model, the measured adrenaline and dopamine concentration at 1 2 T was higher than expected (66.7 (7.5)% (mean (SD)) and 68.0 (4.4)%, respectively, P < 0.001). At the calculated time to delivery, neither drug reached target concentration. In a VLBW neonate model, the measured adrenaline and dopamine concentration at 1 2 T was higher than expected (92.2 (7.1)% and 97.1 (3.1)%, respectively, P < 0.001). Adrenaline reached target concentration at 27 (11) min and dopamine at 56 (12) min, times significantly shorter than calculated. The measured quantity of adrenaline and dopamine delivered was lower (P < 0.001) than calculated in all tested combinations except adrenaline at proximal connection (97.2 (3.4)%, P = 0.097) in the VLBW neonate model. Using the most proximal available infusion connection considerably improves drug delivery times and drug doses delivered, which is critical during the administration of short-acting cardiovascular medications. [ABSTRACT FROM AUTHOR]

Continuous peripheral nerve block catheters are simple in concept: percutaneously inserting a catheter adjacent to a peripheral nerve. This procedure is followed by local anesthetic infusion via the catheter that can be titrated to effect for extended anesthesia or analgesia in the perioperative period. The reported benefits of peripheral nerve catheters used in the surgical population include improved pain scores, decreased narcotic use, decreased nausea/vomiting, decreased pruritus, decreased sedation, improved sleep, and improved patient satisfaction. [ABSTRACT FROM AUTHOR]

Background: Arterial pressure lability is common during the process of replacing syringes used for norepinephrine infusions in critically ill patients. It is unclear if there is an optimal approach to minimise arterial pressure instability during this procedures. We investigated whether 'double pumping' changeover (DPC) or automated changeover (AC) reduced blood pressure lability in critically ill adults compared with quick syringe changeover (QC).Methods: Patients requiring a norepinephrine infusion syringe change were randomised in a non-blinded trial undertaken in six ICUs. Randomisation was minimised by norepinephrine flow rate at inclusion and centre. The primary outcome was the frequency of increased/decreased mean arterial pressure (defined by 15 mm Hg from baseline measurements) within 15 min of switching the syringe compared with QC.Results: Patients (mean age: 64 (range:18-88)) yr were randomly assigned to QC (n=95), DPC (n=95), or AC (n=96). Increased MAP was the commonest consequence of syringe changeovers. MAP variability was most frequent after DPC (89/224 changeovers; 39.7%) compared with 57/223 (25.6%) changeovers after quick syringe switch and 46/181 (25.4%) in patients randomised to receive automated changeover (P=0.001). Fewer events occurred with QC compared with DPC (P=0.002). Sensitivity analysis based on mixed models showed that performing several changeovers on a single patient had no impact. Both type of changeover and norepinephrine dose before syringe changeover were independently associated with MAP variations >15 mm Hg.Conclusions: Quick changeover of norepinephrine syringes was associated with less blood pressure lability compared with DPC. The prevalence of MAP variations was the same between AC and QC.Clinical Trial Registration: NCT02304939. [ABSTRACT FROM AUTHOR]

To develop a technique for ultrasound-guided continuous median and ulnar peripheral nerve block in horses. Anatomical and prospective experimental study. A total of 16 thoracic limbs from horse cadavers and 18 adult horses. This study was conducted in three phases. Phase 1: Dissection of median and ulnar nerves in the antebrachial region of two cadaver limbs to identify localizing landmarks. Description of sonoanatomy in 14 cadaver limbs using ultrasound-guided perineural infiltration of a combination of cellulose gel (5 mL), contrast medium (4 mL) and methylene blue (1 mL). Catheters were inserted between the perineural sheath and epineurium in six limbs, followed by computed tomography. Phase 2: Ultrasonographic images of the limbs of 18 healthy horses of different breeds were used to define an acoustic window and optimize the approach to nerves. Phase 3: Two case reports of horses with chronic pain of different etiologies. Catheters were inserted between the epineurium and paraneural sheath of the median and/or ulnar nerves guided by ultrasound, followed by continuous infusion of 0.4% ropivacaine. Information from phase 1 was used to direct needle insertion, solution dispersion and catheter implantation in phase 2, which resulted in 100% technique accuracy. In response to the peripheral nerve block, pain reduction was apparent in the two clinical cases by increased weight bearing in affected limbs and decreased requirement for systemic analgesic medications. No local reactions were observed. The ultrasound technique allowed real-time visualization of needle, catheter and drug dispersion and resulted in a high success rate for nerve blocks. The horses administered a median and ulnar nerve block exhibited no discomfort or signs of infection at the catheter insertion site. Further studies are warranted to validate the efficacy of this technique. [ABSTRACT FROM AUTHOR]

Background: Syringe infusion pumps are used for the precise continuous administration of intravenous drugs. Their compliance and mechanical deficiencies have been found to cause considerable start-up delays, flow irregularities during vertical displacement, as well extensive delays of occlusion alarms at low infusion rates. The aim of this study was to evaluate the performance of several modern syringe infusion pumps at low infusion rates and the impact on drug concentration.Methods: Seven currently marketed syringe infusion pump assemblies were assessed in an in vitro study during start-up, vertical displacement manoeuvres, and infusion line occlusion at a set flow rate of 1 ml h-1. The measured data were used as input for a pharmacokinetic simulation modelling plasma concentration during a standard neonatal continuous epinephrine infusion.Results: The mean time from starting the infusion pump to steady-state flow varied from 89 to 1622 s. The zero-drug delivery time after lowering the pump ranged from 145 to 335 s. In all assemblies tested, occlusion alarm delays and measured flow irregularities during vertical displacement manoeuvres resulted in relevant deviations in plasma epinephrine concentration (>25%) as calculated by the pharmacokinetic simulation model.Conclusion: Problems with the performance of syringe infusion pump assemblies can have considerable impact on plasma drug concentration when highly concentrated short-acting cardiovascular drugs are administered at low flow rates. The problems, which affected all assemblies tested, are mainly related to the functional principle of syringe infusion pumps and will only partially be solved by incremental improvements of existing equipment. [ABSTRACT FROM AUTHOR]

Background: The Institute for Safe Medication Practices (ISMP) describes high alert medications (HAM) as medications that represent a heightened risk of patient harm when used in error. IV smart pumps with dose error reduction systems (DERS) were created to help address medication administration errors. Compliance with DERS provides a measure of how accurately a hospital uses smart pump technology to reduce IV medication error.Objective: The primary purpose of this research was to use the REMEDI dataset, an aggregate, multi-hospital database inclusive of smart pump analytics, to improve the current understanding of clinical practices for IV HAM administration.Methods: Descriptive analyses and analysis of variance (ANOVA) were used to test for differences in the mean DERS alert override rate, and mean DERS alert override to reprogram ratio between non-HAM and HAM overall, by hospital system, and by pump type.Results: High mean override rates for non-HAM (73.8%) and HAM (75.8%) and high override to reprogram ratios for both non-HAM (7.30) and HAM (9.92) were seen. No significant differences were found in override rates (p = 0.23) and override to reprogram ratios (p = 0.06) between non-HAM and HAM. By hospital system, significant variability in override rates and override to reprogram ratios were seen. By pump type, there were no significant differences in the mean override rates (Baxter: p = 0.09; BD p = 0.34; ICU Medical p = 0.18) and the mean override to reprogram ratios (Baxter p = 0.84; BD p = 0.03; ICU Medical p = 0.63) between non-HAM and HAM.Conclusions: These findings indicate that the majority of alerts generated are bypassed by clinicians at the point of care, a symptom of alert fatigue. Given the potential for significant patient harm with HAM and the high DERS alert override rates that routinely occur during IV medication administration, this study provides further support for clinician-driven IV smart pump innovation to improve alert fatigue. [ABSTRACT FROM AUTHOR]

We have demonstrated the use of conductive polylactic acid (PLA) filament for dose monitoring in a syringe-less wearable infusion pump. A channel reservoir is inlaid with conductive PLA filament. As the liquid medium is dispensed via gas pressurization by an built-in electrolysis chamber, the effective impedance of the conductive PLA filament/liquid medium column changes as well. This allows the dispensed volume to be monitored via the output voltage across a series resistor. Using 5 V sinusoidal input voltage, the output voltage decreased from ∼1.3 to ∼0.13 V as the dispensed volume of 0.1 mol/L PBS increased from 0 to 1000 μL. Similarly, the output voltage for insulin analog decreased from ∼0.64 to 0.126 V for the same volume displaced. Repeated dispensing runs with 0.1 mol/L PBS showed good consistency (standard deviation less than 10 mV). The rate of change of the output voltage with elapsed time varied accordingly for the different flow rates (0.25–1.00 mL/h or ∼4–17 μL/min). At electrolysis voltages of 1.5 and 5 V, the respective output voltage were 1.04 and 0.33 V. These corresponded to flow rates of ∼3 and 10 mL/h (∼50 and 160 μL/ min). [ABSTRACT FROM AUTHOR]

• A non-electrical and atmospheric pressure driven infusion pump was developed. • This infusion pump prototype works by inflating a sleeping-bag-shaped air bag to compress a drip bag. • This study investigated the behaviors of the drip bag and the air bag independently to quantify their respective effects. • 'Wrinkles' that appeared on the drip bag surface, trapped, and isolated small quantities of liquid inside the drip bag. • 'Wrinkles' also affected the adhesiveness of contact surfaces between the air bag and the drip bag. A novel non-electrical infusion pump prototype, driven by a vacuum-piston-cylinder, was developed for intravenous (IV) fluid therapy. This infusion pump prototype, called as AIR-BAG, was designed to work by inflating a sleeping-bag-shaped air bag to compress a drip bag for producing an infusion flow rate. This study was aimed at investigating the influencing factors on its flow performance by measuring the discharge flow rate stability using a gravimetric test bench. In determining the influencing factors, this study took an investigatory strategy of studying the behaviors of the drip bag and the air bag independently in order to examine and quantify their respective effects on the overall flow performance. From the investigation, it was found that 'wrinkles', created on the drip bag surface, trapped, and isolated small quantities of liquid inside the drip bag, leading to a rapid drop of liquid pressure inside the drip bag and hence a decrease of infusion flow rate. Due to the existence of the wrinkles, the adhesiveness of contact surfaces between the air bag and the drip bag, which was crucial for transition of pressurizing force, became highly affected, consequently further deteriorating the flow performance of AIR-BAG. The findings and understandings from this investigation will path the way for further improvement of prototype AIR-BAG. [ABSTRACT FROM AUTHOR]

[Display omitted] Subvisible particles generated during the preparation or administration of biopharmaceuticals might increase the risk of immunogenicity, inflammation, or organ dysfunction. To investigate the impact of an infusion system on the level of subvisible particles, we compared two types of infusion sets based on peristaltic movement (Medifusion DI-2000 pump) and a gravity-based infusion system (Accu-Drip) using intravenous immunoglobulin (IVIG) as a model drug. The peristaltic pump was found to be more susceptible to particle generation compared to the gravity infusion set owing to the stress generated due to constant peristaltic motion. Moreover, the 5-µm in-line filter integrated into the tubing of the gravity-based infusion set further contributed to the reduction of particles mostly in the range ≥ 10 µm. Furthermore, the filter was also able to maintain the particle level even after the pre-exposure of samples to silicone oil-lubricated syringes, drop shock, or agitation. Overall, this study suggests the need for the selection of an appropriate infusion set equipped with an in-line filter based on the sensitivity of the product. [ABSTRACT FROM AUTHOR]

Patients with thalassemia need regular blood transfusions to maintain normal growth and suppression of ineffective erythropoiesis. Packed red blood cell (RBC) units can be delivered by infusion pumps (IPs); however, IPs may cause mechanical stress-induced RBC lysis. This study aimed to investigate the biomarkers of hemolysis related to transfusion techniques in patients with thalassemia. Eighty-one thalassemia patients compared to those 42 healthy controls in terms of hemolysis markers (hemoglobin, plasma free hemoglobin (Hb), haptoglobin, potassium (K), lactate dehydrogenase (LDH)) before transfusion. Considering the age and peripheral venous diameter of the patient, the physician decided on the caliber of vascular access device (22 G or 24 G) for transfusion and the method to be used (gravitational method [GM] or IP). Hemolysis markers were repeated after transfusion in thalassemia patients. Packed RBC units were transfused to 24 (30 %) patients by IP and 57 (70 %) patients by GM. Plasma free Hb was significantly increased from 4.76 ± 7.92 mg/dL to 9.01 ± 7.66 mg/dL following transfusion (p < 0.001). There was no significant difference between IP and GM in terms of plasma free Hb increase. Post-transfusion plasma free Hb, LDH, and K levels significantly increased in patients who were transfused with 24 G catheters compared to those transfused with 22 G. An elevation in LDH levels was detected after transfusion with volumetric IPs; however, plasma free Hb or K levels were not affected by the transfusion method. Studies are needed to determine the factors associated with hemolysis after transfusion. [ABSTRACT FROM AUTHOR]

When fertility is impaired by anticancer treatment, spermatogonial stem cell transplantation (SSCT) could be used as a fertility restoration technique later on in life. Previously, we have demonstrated that a testicular cell suspension could be injected into a human cadaver testis, however, leakage to the interstitium was observed. In this study, injection of mouse testicular cells at an injection height of 50 cm (hydrostatic pressure) or via an automated injection pump (1400 µl, 2600 µl and 3000 µl) was evaluated. Significant difference in the filled radioactive volume was reached between the group in which 1400 µl was injected with an infusion pump and the groups in which 2600 µl ( P = 0.019) or 3000 µl ( P = 0.010) was injected. In all experimental groups green fluorescent protein positive (GFP + ) cells were observed in the seminiferous tubules. In conclusion, a lower injection height did not resolve the leakage of the injected cells to the interstitium. Using the infusion pump resulted in more efficient filling of the seminiferous tubules with lower interexperimental variability. Although leakage to the interstitium was still observed, with further optimisation, the use of an infusion pump for clinical application is advantageous. [ABSTRACT FROM AUTHOR]

We validated the usability of a new infusion pump interface designed with a situated Cognitive Engineering approach by comparing it to a reference interface using a novel testing method employing repeated measurements and process measures, in addition to traditional outcome measures. The sample consisted of 25 nurses who performed eight critical tasks three times. Performance measures consisted of number and type of errors, deviations from a pre-established normative path solution, task completion times, number of keystrokes, mental effort and preferences in use. Results showed that interaction with the new interface resulted in 18% fewer errors, 90% fewer normative path deviations, 42% lower task completion times, 40% fewer keystrokes, 39% lower mental effort and 76% more subjective preferences in use. These outcomes suggest that within the scope of this case study, combining the situated Cognitive Engineering approach with a novel testing method addresses various shortcomings of earlier testing methods. [ABSTRACT FROM AUTHOR]

Programming infusion pumps has been recognised as a high-risk step and a source of adverse events (Nuckols et al., 2008; Hyman, 2010). Literature describing infusion pump loading dose errors and NORepinephrine complications is scarce (Girard et al., 2010). This case study presents the first ever report of an inadvertent overinfusion of NORepinephrine due to the loading dose option on the infusion pump, and resulting cardiac arrest of the patient. A patient was admitted to the emergency room and started on a NORepinephrine infusion inadvertently as a loading dose rather than a primary infusion. Historical values for the loading dose volume to be infused (VTBI) and primary rate were not adjusted during the setup. Eight hours and 58 minutes later, the loading dose VTBI reached 0mL and the pump reverted to the historical primary rate of 999mL/hour. The event log showed that 37.1 mL of NORepinephrine was infused resulting in an equivalent calculated bolus dose of 1.8mg administered in two minutes. The patient suffered a cardiac arrest and the infusion was stopped. No faults were found with the pump. Herein, we discuss our analysis of the pump event logs and propose further safety strategies and interventions. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents experimental investigations of a novel miniature reciprocating ball pump (RBP) as a potential infusion pump or drug delivery system. The objectives of this study are to validate the RBP''s operational principle and to evaluate its performance. In the tests, the basic functionality of the pump has been established at different pumping frequencies ranging from 1.667Hz (100rpm) to 4.167Hz (250rpm) against different pressure heads ranging from 0mmH2O and 100mmH2O. In addition, experimental results show that the RBP can deliver a higher flow rate with a volumetric efficiency of 120% as compared to a conventional single acting reciprocating pump running under the same operating conditions. [Copyright &y& Elsevier]

Abstract: Aims: Clinical use of olanzapine has been suggested to be associated with weight gain and adiposity in schizophrenic patients. While studies in experimental animals have noted weight gain in olanzapine-treated female rats, these findings have yet to be replicated in males. This study investigated the effect of chronic subcutaneous infusion of olanzapine in male rats via a recently developed electrical microinfusion pump. Main methods: An electrical microinfusion pump was subcutaneously implanted in male Sprague–Dawley rats who were then chronically administered olanzapine. Plasma olanzapine concentration and body weight were monitored, and fat pads were weighed after six weeks'' olanzapine treatment. Key findings: Plasma olanzapine concentration plateaued within 4h of commencement of chronic olanzapine 1.5mg/animal/day infusion and remained constant until day 21. Six-week infusion of olanzapine at 1.5 but not 1mg/animal/day induced significant adiposity in subcutaneous, epididymal, and retroperitoneal fat. Body weight and food intake values did not differ between olanzapine- and vehicle-treated rats throughout the experiment. Significance: The present study demonstrated that chronic infusion of olanzapine induced adiposity in male rats without inducing weight gain or hyperphagia, even with sufficient plasma concentration. This report is the first to provide information about adiposity-inducible plasma concentration of olanzapine in male rats. [Copyright &y& Elsevier]

Abstract: A fundamental study to investigate the emission characteristics of ethanol-blended fossil fuels is presented. Employing a heterogeneous experimental setup, emissions are measured from diffusion flames around spherical porous particles. Using an infusion pump, ethanol–fossil fuel blend is transpired into a porous sphere kept in an upward flowing air stream. A typical probe of portable digital exhaust gas analyzer is placed in and around the flame with the help of a multi-direction traversing mechanism to measure emissions such as un-burnt hydrocarbons, carbon monoxide and carbon dioxide. Since ethanol readily mixes with water, emission characteristics of ethanol–water blends are also studied. For comparison purpose, emissions from pure ethanol diffusion flames are also presented. A simplified theoretical analysis has been carried out to determine equilibrium surface temperature, composition of the fuel components in vapor-phase and heat of reaction of each blend. These theoretical predictions are used in explaining the emission characteristics of flames from ethanol blends. [ABSTRACT FROM AUTHOR]

Abstract: Background: “Smart” intravenous infusion pumps (Smart IV pumps) are increasingly being implemented in hospitals to reduce medication administration errors. Objectives: This study examines nurses’ experience with the implementation and use of a Smart IV pump in an academic hospital. Method: Data were collected in three longitudinal surveys: (a) a pre-implementation survey, (b) a 6-week-post-implementation survey, and (c) a 1-year-post-implementation survey. We examined: (a) the technology implementation process, (b) technical performance of the pump, (c) usability of the pump, and (d) user acceptance of the pump. Results: Initially, nurses had a somewhat positive acceptance of the Smart IV pump technology that significantly increased one year after implementation. User experiences associated with the pump in general improved over time, especially perceptions of pump efficiency. However, user experience with the pump implementation process and pump technical performance did not consistently improve from the pre-implementation survey to the post-implementation survey. Several characteristics of pump technical performance and usability influenced user acceptance at the one-year post-implementation survey. Discussion: These data may be useful for other institutions to guide implementation and post-implementation follow-up of IV pump use; other institutions could use the survey instrument from this study to evaluate nurses’ perceptions of the technology. Our study identified several characteristics of the implementation process that other institutions may need to pay attention to (e.g., sharing information about the implementation process with nurses). [Copyright &y& Elsevier]

Abstract: A fundamental experimental study to determine the burning rates of ethanol and ethanol-blended fossil fuels is presented. Pure liquid ethanol or its blends with liquid fossil fuels such as gasoline or diesel, has been transpired to the surface a porous sphere using an infusion pump. Burning of the fuel takes place on the surface of the porous sphere, which is placed in an air stream blowing upwards with a uniform velocity at atmospheric pressure and temperature under normal gravity conditions. At low air velocities, when ignited, a flame envelopes the sphere. For each sphere size, air stream velocity and fuel type, the fuel feed rate will vary and the same is recorded as the burning rate for that configuration. The flame stand-off distances from the sphere surface are measured by post-processing the digital image of the flame photograph using suitable imaging software. The transition velocity at which the flame moves and establishes itself at the wake region of the sphere has been determined for different diameters and fuel types. Correlations of these parameters are also presented. [Copyright &y& Elsevier]

Abstract: Introduction: The iPRECIO™ (Primetech Corporation, Tokyo, Japan) is a new form of pump for infusing small laboratory animals. The key features of the iPRECIO™ are that it can be implanted within the animal, it is refillable, and it is programmable. The infusion start-points and end-points are adjustable, infusion rate can be altered, and the infusion solution can be changed after the pump is implanted. In order to confirm the precision of the iPRECIO™, in vivo and in vitro experiments were employed. Methods: In the in vitro experiment, at the excretion rate of 1 μl/h for 336 h, 15 μl/h for 96 h, and 30 μl/h for 120 h, the decrease in each pump weight was used to estimate the actual excretion volume. In the in vivo experiments, the iPRECIO™ was chronically implanted in rats, angiotensin II was infused, and arterial pressure (AP) was monitored. Results: In the in vitro experiment, the volume of solution excreted from the pump increased with time, and the volume excreted matched the programmed volume. The infusion rate also changed at the scheduled time. In the in vivo experiment, AP increased and decreased on schedule, and a dose-dependent pressor response to angiotensin II occurred. Furthermore, after exchanging saline with angiotensin II, AP increased and decreased on schedule. Discussion: Present data of the in vitro and in vivo experiments indicates that the iPRECIO™ worked precisely, making it suitable for a variety of experiments involving small laboratory animals. [Copyright &y& Elsevier]

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Abstract: A dog model was developed to test the capacity of boosters for antiretroviral medication. Two dogs were implanted with a modified constant-flow Codman 3000® infusion pump, adapted to release viscous solutions of darunavir (TMC114) at a constant rate of 25mg/dog/day in the venous blood stream. Booster candidates were given by oral gavage for at least 4 days up to maximum 7 days in cross-over fashion, separated by a wash-out period of minimum 1 week. The booster candidates were tested at doses of 20 and/or 40mg/kg/day: blood sampling for determination of the boosting effect was performed on the last day of booster administration. The model allowed to (1) compare the boosting ratio of these booster candidates based on the exposure (determination of the area under the curve (AUC) of darunavir in presence versus absence of the booster candidate), (2) detect delay in boosting activity by evaluation of the shift of C max of darunavir following booster administration versus the C max of the booster candidate) and (3) calculate the intrinsic booster capacity, by correcting for the systemic exposure of booster candidate by normalizing the booster ratio for the booster''s AUC. The latter parameter (intrinsic booster capacity) allows to determine the booster''s metabolic contribution in inhibiting the metabolism of antiretroviral medication (most likely via inhibition of CYP3A4), minimizing the impact of potential effects of the booster at the level of the gastro-intestinal tract. [Copyright &y& Elsevier]

Abstract: Factors such as insufficient drug potency, non-compliance and restricted tissue penetration contribute to incomplete suppression of Human Immunodeficiency Virus (HIV) and the difficulty to control this infection. Infusion via standard catheters can be a source of infection, which is potentially life threatening in these patients. We developed an implantable infusion pump, allowing to accommodate large volumes (16–50mL) of high viscous solutions (up to 23.96mPas at 39°C) of anti-HIV agents and providing sustained release of medication: a standard Codman® 3000 pump, which was initially developed to release aqueous solutions (∼0.7mPas) into the spinal cord such as for pain medication, was transformed for release of viscous solutions up to 40mPas by adapting the diameter of the capillary flow restrictor, the capillary length and way of catheterisation—by placing the indwelling catheter in the vena cava. A pilot study of the pump implanted in 2 dogs showed continuous steady-state release of the protease inhibitor darunavir (25mg/dog/day administered for 25 days), thereby achieving plasma concentration levels of ∼40ng/mL. Steady-state plasma levels were reproducible after monthly refill of the pumps. In conclusion, the implantable adapted Codman® 3000 constant-flow infusion pump customized to anti-HIV therapy allows sustained release of anti-HIV medication and may represent an opportunity to reduce the pill burden and complexity of dosing schemes associated with common anti-HIV therapy. [Copyright &y& Elsevier]

Purpose: This prospective, randomized, double-blind study with a placebo group and 2 experimental groups evaluated the efficacy of continuous low-dose bupivacaine infiltration by infusion pump after arthroscopic rotator cuff repair. Methods: Sixty patients undergoing arthroscopic rotator cuff repair received a bolus injection in the subacromial space of 35 mL of 0.25% bupivacaine with 1:200,000 epinephrine at surgical closure and were randomized to 1 of 3 groups: 0.25% bupivacaine at 2 mL/hr (n = 20), 0.25% bupivacaine at 5 mL/hr (n = 20), or saline at 5 mL/hr (n = 20) via infusion pump into the subacromial space. Pain was evaluated using the visual analog scale (VAS) and narcotic consumption was measured until 48 hours after surgery and converted to dose equivalents (DE). Results: Sixty patients used the infusion pump for a mean of 43.9 hours (range, 15.50 to 50.75 hrs). Mean total narcotic consumption, expressed in DEs, was 2.24 for the 2-mL group, 3.52 for the 5-mL group, and 2.32 for the placebo group. Mean pain score was 2.9 for the 2-mL group, 3.6 for the 5-mL group, and 3.3 for the placebo group. There were no differences in operating room time or infusion pump use time among groups. The 2-mL group had a nonsignificant trend toward less pain and lower narcotic consumption. The 5-mL group evidenced a nonsignificant trend toward more pain and higher narcotic consumption. Conclusions: This study neither supports nor refutes the use of infusion pumps. We hypothesized that the placebo group would experience greater pain than the 5-mL group; however, a nonsignificant trend toward the contrary occurred. A trend toward less pain in the 2-mL group was not significant. Level of Evidence: Level II, randomized controlled trial of therapeutic treatment that lacks statistical significance and narrow confidence intervals. [Copyright &y& Elsevier]

Purpose: This study was performed to evaluate the efficacy of interscalene regional blocks and infusion pumps for postoperative pain control after arthroscopic subacromial decompression with or without arthroscopic rotator cuff repair. Methods: Seventy-six patients were included in the prospective study. Participants were randomized into 4 treatment groups: (1) interscalene regional block, (2) infusion pump with 0.5% bupivacaine, (3) interscalene block combined with an infusion pump containing 0.5% bupivacaine, and (4) interscalene block combined with an infusion pump containing 0.9% saline solution. The interscalene regional block was performed with a nerve stimulator. Infusion pump catheters were positioned in the subacromial space. Visual analog scale (VAS) data were collected preoperatively, at 1 and 2 hours postoperatively, and daily for an additional 6 days postoperatively. An analysis of variance with a Student-Newman-Keuls post hoc test was used to identify statistically significant (P < .05) differences in VAS scores between the groups at each time point. Percentages of patients who took medication for pain management in the recovery room were compared between the 4 groups by use of χ2 analysis. Results: Significant differences were noted in VAS scores postoperatively. Group 2 (pump only) had significantly higher scores than all other groups for the first 2 hours. Furthermore, group 4 (block and pump filled with saline solution) had significantly lower VAS scores than group 1 (block only) at 1 hour. This difference was no longer significant by the second hour. The percentage of patients who required oral narcotics or intravenous pain medication was significantly larger for group 2 than for the other groups. Conclusions: The interscalene regional block provided more pain relief than infusion pumps immediately after arthroscopic shoulder surgery. Infusion pumps did not significantly reduce pain levels after the blocks wore off. Level of Evidence: Level II, prospective comparative therapeutic study. [Copyright &y& Elsevier]

Abstract: Patients followed at home parenteral nutrition (HPN) in our adult and paediatric centers, complain regularly with noise pollution generated by the “bubble air” alarms, and patients do not seem to be exposed in the same way. The aim of this study was to determine the precise impact of two factors empirically suspected to play a role into the bubble air genesis: pumping technology used (with a compartment or linear with fingers) and the presence of injectable lipid emulsion (ILE). Six pumps from three different models (two linear with fingers mechanism and one with compartment) were used and infusions of mixtures with different lipid proportions were realized. For each infusion, volume of emitted gas was measured and number of “bubble air” alarms counted. A significant difference between three pump models is highlighted without a strong proof that only pumping technology is alone in charge. ILE decrease the volume of gas emitted proportionally to its concentration. Emitted gas are dissolved gas. This identification of two factors supporting “bubble air” alarms should allow several adaptations into practices which contribute to improve patient''s quality of life. [Copyright &y& Elsevier]

Most brain mapping techniques require immobilization of the subject, which extinguishes all but the simplest behaviors. We applied in freely moving rats an implantable microbolus infusion pump (MIP) which can be triggered by remote activation for the injection of the cerebral blood flow tracer [14C]iodoantipyrine during behavioral activation. Consistent with previous electrophysiological, metabolic and brain anatomic studies, CBF-related tissue radioactivity (CBF-TR) increased in acoustic cortex during a 1000 Hz/8000 Hz alternating tone. In response to an acute foot-shock, CBF-TR increased in visual cortex, parietal association cortex, and extended into primary motor cortex, and primary somatosensory cortex mapping the trunk. These results support the utility of implantable pumps as adjunct tools for studying cerebral activation during behavioral challenges in nontethered, nonrestrained animals. [Copyright &y& Elsevier]

Study Objectives: To determine the accuracy and reliability of intravenous infusion, as well as magnetic resonance image effect of the Medfusion 2010 infusion pump (Medex Medical Supplies, Inc., Duluth, GA) at distances of 2, 4, 8, 12, and 16 feet from a 1.5 Tesla MRI magnet over a four-week time interval, using infusion rates that would correspond to those of propofol administration.Design: Prospective, open-label study.Setting: Radiology department MRI in an American academic medical center.Interventions: Five infusion pumps, including one outside the MRI suite as control, were tested. Pumps were evaluated at distances of 2, 4, 8, 12, and 16 feet from a 1.5 Tesla magnet. One pump at distances of 2 and 16 feet was tested during 30 and 90 hours of operation, respectively. Three pumps at distances of 4, 8, and 12 feet were tested during 120 hours of operation. Pump batteries were recharged for 18 hours outside the MRI suite between the 6-hour test periods. Distilled, deionized water was infused from a 30-mL or 60-mL syringe via a 36-inch Medex small-bore extension set into a graduated collection cylinder at rates of 5, 10.5, 21, or 42 mL/hr. Each rate was increased to the next infusion rate level at 30-hour weekly intervals. The collection cylinder with infused water was weighed on an electronic scale accurate to within ±0.001 g. Analysis of variance and regression analysis were used to analyze data. A p < 0.05 value was considered statistically significant.Measurements and Main Results: There was no significant difference comparing the grams weight of volume measured and the mL volume visualized within and between groups at varying distances from the magnet. Increasing infusion rates resulted in corresponding increases in volume delivered irrespective of the distance from the magnet.Conclusions: The Medfusion 2010 infusion pumps were found to be reliable and accurate, without causing failure or any significant degradation of MRI images compared to control at infusion rate of 42 mL/hr at a distance of 2 feet for 30 hours; and a rate of 5.0, 10.5, 21, and 42 mL/hr at 16 feet for 90 hours; and at 4, 8, and 12 feet for 120 hours of operation. [Copyright &y& Elsevier]

Résumé: L’indication d’une radiothérapie externe est parfois posée chez des patients porteurs d’un dispositif médical implantable comme les pompes diffuseurs. La tolérance à l’irradiation de ce type de dispositif est peu, voire pas étudiée. Nous rapportons ici le cas d’une patiente que nous avons traitée par irradiation pelvienne pour un cancer du col utérin et qui avait un dispositif médical implantable dans la fosse iliaque. Nous avons aussi fait des tests sur cinq pompes paramétrées, qui ont montré que ces dispositifs ont une bonne tolérance à l’irradiation. [ABSTRACT FROM AUTHOR]

Abstract: Compartment syndrome caused by an infiltrated intravenous catheter has been previously reported, but there are no reports of compartment syndrome caused by fluids and/or medications dispensed by a properly functioning drug infusion pump. A case in which a commonly used drug infusion pump delivered propofol and remifentanil under high pressure, leading to compartment syndrome, is presented. [Copyright &y& Elsevier]

Abstract: Background: Programming intravenous (IV) infusion pumps challenges nursing students and may cause harm to patients if done improperly. A virtual IV pump module was developed to improve learner performance. Method: Nursing students in the control group (n = 26) reviewed IV pump skills in the lab only, and nursing students in the experimental group (n = 17) also reviewed the virtual learning module. Participants were evaluated using a performance checklist and completed a survey about their confidence using IV pumps and satisfaction with the educational module. Results and conclusions: Many participants were not confident performing some of the IV pump skills. Experimental-group participants scored significantly higher than the control group at programming continuous medication infusions (p < .05). Overall, participants were satisfied with the module and found it easy and convenient to use. Results of this study will be used to improve the virtual IV pump educational module. [Copyright &y& Elsevier]