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Background: Critically ill patients frequently need blood transfusions. For safety, blood must be delivered via syringe infusion pumps, yet this can cause red cell damage and increase the rate of haemolysis. \ud Aims and objectives: To evaluate biochemical and haemolytic markers of red blood cells transfused in three different, common type of syringe infusion pumps with two different infusion rates (10 and 100 ml/h).\ud Methods: A lab-based study using aliquots of 16 red blood cells bags was undertaken. Haemolysis markers (total haemoglobin(g/dl), haematocrit(%), free haemoglobin(g/dl), potassium(mmol/L), lactate dehydrogenase(U/L), osmolality(mOsm/kg), pH, degree of haemolysis(%)) were measured before and after red blood cells infusion and exposure. Three different syringe infusion pumps brands (A, B and C) were compared with two different infusion rates (10 and 100 ml/h). \ud Results: The total haemoglobin fell significantly in all red blood cells units during manipulation (Pre-infusion: 26.44±5.74; Post-exposure: 22.62±4.00; p=0.026). The degree of haemolysis significantly increased by 40% after manipulation of the red blood cells. Syringe infusion pump A caused a threefold increase in potassium levels (3.78±6.10) when compared to B (-0.14±1.46) and C (1.63± 1.98) (p=0.015). This pump also produced the worst changes, with an increase in free haemoglobin (0.05±0.05; p=0.038) and more haemolysis (0.08±0.07; p=0.033). There were significant differences and an increase in the degree of haemolysis (p=0.004) in the infusion rate of 100 mL/h. \ud Conclusions: Syringe infusion pumps may cause significant red blood cell damage during infusion, with increases in free haemoglobin, potassium and the degree of haemolysis. Some pumps types, with a cassette mechanism, caused more damage.\ud Relevance to clinical practice: In many ICUs, bedside nurses are able to consider infusion pump choice and understanding the impact of different pump types on RBC during a transfusion provides the nurses with more information to enhance decision-making and improve the quality of the transfusion.

Objectives Transnasal pulmonary aerosol delivery using high-flow nasal cannula (HFNC) devices has become a popular route of aerosol administration in toddlers. Clinically, albuterol is administered using an infusion pump or unit doses. However, little evidence is available to compare the two administration strategies. Methods A toddler manikin (15 kg) with appropriate anatomic airway was connected with collecting filter to a simulator of distressed breathing. HFNC device with mesh nebulizer placed at the inlet of a humidifier at 37°C, with the gas flow set at 25 and 3.75 L/min. Five milligrams of albuterol was delivered in all experiments. With infusion pump administration, albuterol concentrations of 5 and 1 mg/mL were delivered at 4 and 20 mL/hr for 15 minutes. With unit dose administration, 1 mL (5 mg/mL) and 2 mL (2.5 mg/mL) of albuterol were nebulized. Additional tests with mouth open and nebulizers via mask were using 5 mg/1 mL for mesh nebulizer and 5 mg/3 mL for jet nebulizer (n = 3). The drug was eluted from the filter and assayed with UV spectrophotometry (276 nm). Results The inhaled dose was higher with unit dose than infusion pump administration with gas flows of 25 L/min (2.66 ± 0.38 vs 1.16 ± 0.28%; P = .004) and 3.75 L/min (10.51 ± 1.29 vs 8.58 ± 0.68%; P = .025). During unit dose administration, compared with closed-mouth breathing, open-mouth breathing generated a higher inhaled dose at 3.75 L/min and lower inhaled dose at 25 L/min. Compared to the nebulizers via mask with both open and closed-mouth breathing, nebulization via HFNC at 3.75 L/min generated greater inhaled dose, while HFNC at 25 L/min generated lower inhaled dose. Conclusions During transnasal aerosol delivery, the inhaled dose was higher with medication administrated using unit dose than using an infusion pump.

Background: Many studies have investigated drug stability in extended home infusion pumps, but little is known of other factors that may affect the total daily dose the patient receives. It has been noted that up to 40% of these infusions are incomplete after the designated run out time. Aim: This study investigated whether concentration can affect the flow rate of home infusion pumps, and thus the total dose the patient receives in outpatient parenteral antimicrobial therapy (OPAT). Method: The flow rates of 10 different drug and dose formulations (4–18 g in 0.9% sodium chloride) in Baxter LV10 (Old Toongabbie, Australia) infusion pumps were investigated. The pumps were run out at 31°C and weighed at intervals, with flow rate and total volume infused calculated over the 24-h period. Results: Piperacillin/tazobactam 18 g was the only formulation not to meet the minimum standard of 90% of the volume being infused over the 24-h period. This indicates a failure of intended therapy. Across all infusions, the expected dose delivered (DD) can be calculated as %DD = −1.9x + 122.85, where x is the total drug and excipient weight within the infusor. Conclusion: Dose is inversely related to flow rate in the LV10 Baxter infusion pump. Under nominal conditions, any amount greater than 12.02 g in the 240-mL infusion pump will result in an incomplete run out over the 24-h period. Clinicians should be aware that prescribing daily doses higher than 17.28 g may result in

To achieve strict glycaemic control and avoid chronic diabetes complications, individuals with type 1 diabetes (T1D) are recommended to follow an intensive insulin regimen. However, the risk and fear of hypoglycaemia often prevent individuals from achieving the treatment goals. Apart from early insulin suspension in insulin pump users, carbohydrate ingestion is the only option for preventing and treating non-severe hypoglycaemic events. These rescue treatments may give extra calories and cause overweight. As an alternative, the use of low-dose glucagon to counter hypoglycaemia has been proposed as a tool to raise glucose concentrations without adding extra calories. Previously, the commercially available glucagon formulations required reconstitution from powder to a solution before being injected subcutaneously or intramuscularly-making it practical only for treating severe hypoglycaemia. Several companies have developed more stable formulations that do not require the time-consuming reconstitution process before use. As well as treating severe hypoglycaemia, non-severe and impending hypoglycaemia can also be treated with lower doses of glucagon. Once available, low-dose glucagon can be either delivered manually, as an injection, or automatically, by an infusion pump. This review focuses on the role and perspectives of using glucagon to treat and prevent hypoglycaemia in T1D.

Intravenous acetylcysteine is commonly prescribed as a course of three infusions for the management of paracetamol poisoning. Previous studies have demonstrated large variation in administered doses of intravenous acetylcysteine, which has been attributed to numerous factors, including inadequate mixing of infusion bags. The aim of this study was to determine whether the amount of mixing of infusion bags contributes significantly to this variation. Using acetylcysteine doses for a 60–69 kg patient, we added the appropriate volume of acetylcysteine to 5% glucose and subsequently inverted the infusion bags 0–5 times to mix the solutions. Infusion bags were then run through using an infusion pump and acetylcysteine concentrations measured at the beginning and end of the infusions. We found no significant difference between the beginning and end concentrations of acetylcysteine regardless of whether bags were mixed or not; infusion 1 (150 mg kg(−1)) showed beginning and end concentrations of 44.61 and 42.48 mg ml(−1) respectively after 0 mixes, whilst beginning and end concentrations were 44.45 and 44.58 mg ml(−1) respectively after five mixes. The same trend was observed for infusions 2 and 3. This confirmed that mixing does not play a substantial role in variation of drug concentrations; these are likely to be caused by an accumulation of small errors in infusion preparation.

Aims Alpha-2 agonists are direct peripheral vasoconstrictors, which achieve these effects by activating vascular smooth muscle alpha-2 adrenoceptors. The impact of this response during dexmedetomidine infusion remains poorly quantified. Our goal was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD, vasoconstriction) effects of a computer-controlled dexmedetomidine infusion in healthy volunteers. Methods After local ethics committee approval, we studied 10 healthy volunteers. To study the peripheral vasoconstrictive effect of dexmedetomidine without concurrent sympatholytic effects, sympathetic fibres were blocked with a brachial plexus block. Volunteers received a dexmedetomidine target-controlled infusion for 15 min, to a target concentration of 0.3 ng ml-1 . Arterial blood samples were collected during and for 60 min after dexmedetomidine infusion for PK analysis. Peripheral vasoconstriction (PD) was assessed using finger photoelectric plethysmography. PK/PD analysis was carried out using nonlinear mixed-effect models. Results We found that the computer-controlled infusion pump delivered mean concentrations greater than 0.3 ng ml-1 over the 15-min infusion duration. The peripheral vasoconstrictive effect correlated with dexmedetomidine plasma concentrations during and after the infusion. A three-compartment model provided a better fit to the data than a two-compartment model. Conclusions We found that dexmedetomidine-induced vasoconstriction is concentration dependent over time. Dexmedetomidine PK were best estimated by a three-compartment model with allometric scaling. Our results may contribute to future modelling of dexmedetomidine-induced haemodynamic effects.

Background Direct thaw and administration of previously cryopreserved peripheral blood stem cell products is a commonly used practice and should be performed rapidly to reduce cellular damage caused by dimethyl sulfoxide exposure. Cells are typically thawed at the bedside and infused by gravity through a high-flow-rate central venous catheter. An existing nontunneled catheter is occasionally used instead and often results in a slower infusion rate. To ensure expedient and consistent infusions, we validated and implemented the use of an infusion pump for thawed peripheral blood stem cells. Study design and methods Validation was performed in two phases: in vitro simulation and in vivo clinical assessment. Total nucleated cell recovery and viability plus progenitor cell viability and potency were compared in vitro between two cryopreserved peripheral blood stem cell units that were either passed through a preset infusion pump or drained by gravity. The infusion rate, adverse events, and engraftment times were retrospectively compared between patients who received infusions by infusion pump (n = 35) and by gravity (n = 38). Results No significant differences were observed in vitro between the infusion methods for all measured variables. Overall infusion rates were similar in vivo for both groups but were significantly lower for patients who had nontunneled catheters that delivered the infusion by gravity. The time to neutrophil and platelet engraftment was similar for both groups. Conclusion This is the first study to assess the use of an infusion pump for stem cell transplant. The use of an infusion pump for peripheral blood stem cell infusion is safe, provides a reliable and consistent infusion method, and can mitigate the effect of the type of venous access line used.

Background Medication errors during administration are not uncommon and have a higher risk and severity of error. Dose error reduction software (DERS) makes an infusion pump a ‘smart pump’. Aim We present our experience using DERS in an Australian paediatric hospital. Discussion We discuss adapting DERS for use in paediatrics: its limitations, and estimated preventable errors and cost avoidance. Importantly, DERS can prevent medication error in paediatrics.

Experimental interventions that activate specific components of clinical pain are necessary for characterization of underlying mechanisms and pharmacology. Cutaneous hyperalgesia has been described that uses nonpainful heat to induce secondary hyperalgesia. This study evaluated the effect of intravenous alfentanil on experimental cutaneous hyperalgesia created using this method. Eighteen subjects participated in a randomized, double-blinded, placebo-controlled crossover study consisting of 2 sessions, 1 with alfentanil and 1 with placebo. Using a computer-controlled infusion pump, alfentanil or matching placebo was maintained at a constant plasma level of 75 ng/mL for 1 hour followed by the application of a 40°C heat stimulus to the right thenar eminence for 15 minutes. The temperature was raised by 1°C every 15 minutes until the subject reported pain or 45°C was reached. After the end point was reached, the temperature was maintained, and repeat testing was performed. The nonpainful heat created an area of secondary cutaneous hyperalgesia and significant decrease in mechanical pain threshold on heat-treated right vs untreated left during placebo administration. Alfentanil prevented the hypersensitivity when compared to placebo (P < .05) but failed to reduce the area of secondary hyperalgesia created by nonpainful heat when compared to placebo (P = .06). Neither alfentanil nor the heat lamp treatment showed any significant effect on other neurosensory measures. This study demonstrated a reliable production of cutaneous hyperalgesia using a nonpainful stimulus that is affected by the systemic delivery of alfentanil. This model for human cutaneous experimental pain may be a useful method for scientific characterization of analgesics.

Background Although most studies have shown that little haemolysis is induced by infusion pumps, there are some notable exceptions. Only limited data are available on the actual infusion pumps that are most used in hospitals in Quebec and elsewhere, namely, the Infusomat® Space (peristaltic), Plum A+™ (piston) and Colleague® CXE (shuttle) pumps. Methods Haemolysis and potassium levels were compared before and after the use of the three different infusion pumps. Using 135 units of packed red blood cells (RBCs) aged from 10 to 28 days, 27 measurements were taken for each pump at various flow rates (30, 60, 150, 300 and 450 ml/h) and were compared with measurements taken before using the pumps. The range of flow rates was chosen to cover those of paediatric and adult transfusions. Results The shuttle- and piston-type pumps resulted in low haemolysis levels. The peristaltic-type pump produced significantly more haemolysis, which worsened at low flow rates, but the absolute value of haemolysis remained within the range recommended by the regulatory agencies in North America and Europe. Approximately two-thirds of the haemolysis produced by the peristaltic-type pump seemed to be secondary to the use of an antisiphon valve (ASV) on the transfusion line recommended by the manufacturer. Potassium levels did not increase with the use of the pumps. Conclusion Modern infusion pumps widely used in hospitals in Quebec and elsewhere produce non-threatening levels of haemolysis during the transfusion of packed RBCs aged from 10 to 28 days. ASVs appear to induce additional haemolysis, and we do not recommend using them for blood transfusion.

Background 'Brittle diabetes' is frequently attributed to psychological stressors causing insulin omission in young women with Type 1 diabetes. It has received little attention in the recent medical literature. Case report We report the case of an 87-year-old woman who had recurrent episodes of unexplained diabetic ketoacidosis. Despite frequent inpatient monitoring of capillary glucose, her blood glucose levels remained erratic. She experienced a total of 12 episodes of ketoacidosis (some occurring during hospitalization), with 11 episodes occurring over a 3-month period. Several episodes of ketoacidosis required care in a high-dependency unit and up to 32 h of intravenous insulin and fluids. Extensive investigations failed to identify any underlying cause of the recurrent ketoacidosis. Ultimately, the introduction of a continuous subcutaneous insulin infusion pump resulted in improved glycaemic control and avoided the need for further hospitalizations. Conclusion Individuals of advanced age can benefit from insulin pump therapy. The original definition of 'brittle diabetes' referred to patients whose lives were 'constantly disrupted by episodes of hypo- or hyperglycaemia'. Our case reminds us that this clinical entity can result from altered biology and is not always related to psychological stressors.

Background and Objectives Fluid warmers are routinely used to reduce the risk of hypothermia and cardiac complications associated with the infusion of cold blood products. However, warming blood products could generate haemolysis. This study was undertaken to compare the impact of temperature of blood warmers on the per cent haemolysis of packed red blood cells (RBCs) heated at different flow rates as well as non-flow conditions. Materials and Methods Infusion warmers used were calibrated at 41·5°C ± 0·5°C and 37·5°C ± 0·5°C. Cold RBC units stored at 4°C in AS-3 (n = 30), aged 30–39 days old, were divided into half units before being allocated under two different scenarios (i.e. infusion pump or syringe). Results Blood warmers were effective to warm cold RBCs to 37·5°C or 41·5°C when used in conjunction with an infusion pump at flow rate up to 600 ml/h. However, when the warmed blood was held in a syringe for various periods of time, such as may occur in neonatal transfusions, the final temperature was below the expected requirements with measurement as low as 33·1°C. Increasing the flow with an infusion pump increased haemolysis in RBCs from 0·2% to up to 2·1% at a flow rate of 600 ml/h regardless of the warming device used (P < 0·05). No relevant increase of haemolysis was observed using a syringe. Conclusions The use of a blood warmer adjusted to 41·5°C is probably the best choice for reducing the risk of hypothermia for the patient without generating haemolysis. However, we should be cautious with the use of an infusion pump for RBC transfusion, particularly at high flow rates.

Aim Memory impairment is a potential major adverse effect of electroconvulsive therapy (ECT). Some reports have suggested that propofol, an intravenous anesthetic widely used for general anesthesia in ECT, can minimize adverse effects on memory and cognitive function following ECT. The relation between propofol blood level during ECT and memory impairment after the procedure is unknown. We aimed to determine the relation between predicted blood level of propofol administered by target-controlled infusion during ECT and memory impairment after the procedure. Methods Thirty-six patients who underwent a total of 260 series of ECT were enrolled as subjects. Anesthesia was induced with intravenous injection of propofol with a target-controlled infusion pump for predicting blood levels. Orientation and memory testing were performed after completion of ECT. In a subsequent analysis, subjects were divided into early memory recovery (n = 195) and late memory recovery (n = 65) groups. Likewise, for orientation testing,subjects were divided into early recovery (n = 193) and late recovery (n = 67) groups. In both groups, predicted blood propofol levels, total propofol dose, and other variables, such as number of ECT treatments, stimulus energy volume, and spike and slow wave time, were determined for comparison. Results Predicted blood propofol levels and propofol total dose were significantly higher in the early memory recovery group, while no significant differences were observed for the other variables. As for orientation, there were no significant differences between the early and late orientation recovery groups. Conclusions Our data shows that the predicted blood propofol levels and the total dose influences memory impairment after the ECT.

Background Lack of compliance with drug libraries among users of smart infusion pumps undermines the efforts to prevent intravenous medication errors. There are little data on drug library use in Australian clinical practice and the barriers to compliance and effective use remain uncertain. Aim To evaluate the use of a smart infusion pump's drug libraries and to identify barriers to effective drug library use. Method Prescription and programming details of the infusions administered via Alaris IV pumps at a health service were audited. Data were used to assess compliance with and use of the drug libraries. In the event of non-compliance or incorrect use of a drug library, a consented interview was conducted with the nurse to identify barriers. Results Of the 86% (95%CI 83–89) of infusions administered via a drug library, 11% (95%CI 9.1–14) were programmed incorrectly. Interviews with nurses revealed several reasons for non-compliance, e.g. difficulty in using smart infusion pump technology, composition of the drug library. Incorrect drug library use was mainly attributed to failure to check programming during change of nursing shift, change of clinical area or change to a new fluid bag. Conclusion Despite high compliance with correct drug library use, 11% of infusions were programmed incorrectly due to incorrect selection of a drug library or therapy or both. The interviews revealed concerns with understanding smart pump technology and deficiencies in routine checks of drug library programming.

Objectives/Hypothesis The treatment for obstructive sleep apnea syndrome (OSAS) depends on correct localization of upper airway obstruction, exception made for continuous positive airway pressure (CPAP). Drug-induced sleep endoscopy (DISE) with propofol allows this evaluation, but the drug effects on sleep parameters are not yet well established. Our objective was to study by polysomnography (PSG) whether propofol would change sleep parameters by means of a prospective cross-sectional clinical study in a tertiary hospital. Study Design Thirty non-obese subjects (6 controls and 24 OSAS patients) underwent two daytime PSGs, one with DISE and the other without DISE. Methods During DISE exam, propofol was administered intravenously in continuous infusion using a target-controlled infusion pump. The parameters evaluated were: presence of snoring, apnea-hypopnea index (AHI), oxyhemoglobin saturation (SaO2), and sleep macroarchitecture. Results Snoring was absent in all healthy subjects during DISE sleep with propofol, and present in all OSAS patients (100%). AHI and mean SaO2 showed no statistical difference between the two tests, with and without propofol. However, minimum SaO2 was significantly lower during propofol infusion (88.64 for without vs. 85.04 for with propofol; P < 0.01). Regarding sleep macroarchitecture, the tests with propofol significantly increased N3 sleep and totally extinguished REM sleep (P < 0.005). Conclusions The results demonstrate that propofol significantly changes sleep macroarchitecture. However, the main respiratory parameters, AHI and mean SaO2, remained unaffected. Thus, in order to determine the sites of obstruction, propofol DISE used with target-controlled infusion proved to be an effective drug for endoscopic evaluation of patients with OSAS. Level of Evidence 4. Laryngoscope, 123:2300–2305, 2013

A palmtop-sized microfluidic cell culture system is presented. The system consists of a microfluidic device and a miniaturized infusion pump that possesses a reservoir of culture medium, an electrical control circuit, and an internal battery. The footprint of the system was downsized to 87 × 57 mm, which is, to the best of our knowledge, the smallest integrated cell culture system. Immortalized human microvascular endothelial cells (HMEC-1) and human umbilical vein endothelial cells (HUVEC) were cultured in the system. HMEC-1 in the system proliferated at the same speed as cells in a microchannel perfused by a syringe pump and cells in a culture flask. HUVEC in the system oriented along the direction of the fluid flow. Claudin-5, a tight junction protein, was localized along the peripheries of the HUVEC. We expect that the present system is applicable to various cell types as a stand-alone and easy-to-use system for microfluidic bioanalysis.

BACKGROUND: It is unknown whether the use of volumetric infusion pumps for the transfusion of red blood cells (RBCs) or platelet (PLT) concentrates (PCs) affects the quality of the blood components. We therefore investigated the in vitro quality of these components after use of infusion pumps. STUDY DESIGN AND METHODS: Ten different volumetric infusion pumps were used to simulate transfusion with RBCs and PCs. To prevent donor-dependent differences multiple units were pooled and divided into equal portions. The storage time of RBCs was 30 to 35 days (n = 10 experiments), and for PCs, either 2 (n = 5) or 7 days (n = 5). For RBCs an infusion rate of 100 or 300 mL/hr was used, and for PCs, 600 mL/hr. Transfusions without an infusion pump served as a reference. RESULTS: None of the infusion pumps induced an increase of free hemoglobin, annexin A5 binding, or formation of echinocytes in RBCs compared to reference units. In 2- and 7-day-old PCs no effect was shown on PLT concentration, annexin A5 binding, mean PLT volume, and morphology score compared to the reference. The CD62P expression of 2-day-old PCs was significantly lower after transfusion compared to the reference, that is, 11.7 ± 2.1% versus 8.1 ± 1.3% (p

The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of 98%.

Aim: Advanced esophagogastric carcinoma has a poor prognosis. Palliative chemotherapy provides a survival advantage and improved quality of life. Epirubicin, cisplatin and continuous infusional 5-fluorouracil (5-FU) (ECF) is a well-established chemotherapy regimen but a continuous chemotherapy infusion is not always feasible or acceptable. Methods: We conducted a phase I and II trial of a modified version of ECF, utilizing 5-FU as a 24-h infusion on day 1 and day 8 of a 21-day cycle, administered with sodium folinate as a modulator of 5-FU (ECSF). In the phase I study the dose of 5-FU was increased in successive cohorts from 1250 mg/m2, 1500 mg/m2, and 1750 mg/m2 to 2000 mg/m2 per 24 h. Results: Dose limiting toxicity of febrile neutropenia was encountered at 2000 mg/m. The recommended dose for 5-FU was 1750 mg/m2. Overall 29 patients were treated with ECSF of whom 27 were evaluable for toxicity. The response rate was 45% on an intention-to-treat analysis with a complete response rate of 3%. The median response rate was 4.1 months and the median survival was 10.7 months. A total of 23 patients (72%) obtained clinical benefit with improvement in dysphagia or weight gain. central venous catheter (CVC) complications were observed in 12 (41%) patients. Conclusion: ECSF was associated with a response rate and survival similar to that reported with standard ECF. ECSF may provide an alternative regimen to standard ECF when a continuous ambulatory infusion pump is not feasible or not preferred by the patient. CVC complications are a limitation.

Aim: According to a national report on incident analysis, the mental workload that exists during the i.v. medication administration process might affect nurses' visual behavior and, thus, influence the accuracy of the process. This study examined changes in the visual behavior of nurses who operated an infusion pump under the influence of time pressure and dual tasking. Methods: Ten nursing students, 13 experienced nurses, and nine inexperienced nurses, equipped with an eye tracker and instruments that measure the heart rate and breathing frequency, carried out an infusion pump operation in a simulated patient room under three mental workload conditions: without a mental workload, under time pressure, and while dual tasking. Results: Under the time pressure condition, the total visual fixation duration of the procedures was shortened. The experienced and inexperienced nurse groups could shorten the tasks in order of priority but the student group could reduce the tasks only inconsistently. Dual tasking had no influence on the total fixation duration of the procedures. However, the fixation location was influenced by the dual-tasking condition. This condition caused dispersed attention in the student and inexperienced-nurse groups, but not in the experienced-nurse group. Conclusion: Time pressure appears to cause nurses to shorten the duration of infusion pump operation and to reduce the quantity of checking. Dual tasking appears to have no influence on the total visual fixation duration but causes dispersed attention, reducing the quality of checking.

Background We describe the safety, feasibility, and provide a cost-estimate of outpatient high-dose methotrexate administration (HDMTX) among an urban, underserved population. Procedure A retrospective analysis of ambulatory HDMTX administration among osteosarcoma patients, at Montefiore Medical Center's Children's Hospital (Bronx, NY) was performed. HDMTX (12 g/m2) was given intravenously (IV) over 4 hr after urine alkalinization. Patients were discharged home to continue IV hydration and alkalinization delivered via a home infusion pump. Families were instructed to monitor urine pH overnight and management was adjusted according to our institution's treatment algorithm until MTX level ≤0.1 µmol/L. A cost estimate was performed to assess the difference in costs for outpatient versus hypothetical inpatient administrations. Results Of the 97 ambulatory HDMTX administrations, 99% were successfully completed. One patient failed outpatient administration secondary to home infusion pump malfunction. This patient successfully completed subsequent courses as an outpatient. Most patients (72%) had a MTX level of 50 µmol/L at 24 hr. About 26% of courses were associated with grade III or IV neutropenia, 4% were associated with grade III or IV thrombocytopenia and 1% were associated with grade III/IV leukopenia. Compared to a hypothetical hospital inpatient stay, the hospital costs for ambulatory HDMTX were an average of $1400 less per cycle. Conclusion Ambulatory HDMTX administration among an underserved, urban population is safe, feasible, and cost-effective. Pediatr Blood Cancer. 2010;55:1296–1299. © 2010 Wiley-Liss, Inc.

There is potential for inappropriate use of transfusion administration sets when used in combination with modern infusion pumps with consequences for patient safety. The aims of our study were to (i) establish if the design and testing of transfusion sets specified in International Standard ISO 1135-4 are adequate for their current applications, (ii) identify if infusion pumps currently supplied in the UK for blood component administration are suitable for this purpose and (iii) determine the additional control measures needed to be applied by manufacturers and users to ensure patient safety. Keyword literature search was carried out to review and correlate important transfusion parameters with resultant adverse effects. Units for occlusion pressure, flow rate and haemolysis were standardised for ease of comparison. A sample of transfusion set instructions for use was reviewed. Principal suppliers of infusion pumps to the UK market were surveyed to identify those sold for blood transfusion, their recommended operating parameters and compatible transfusion sets. Previous work showed clinically unacceptable haemolysis at pressures above 40 kPa. Modern infusion pumps operate under negative pressures of up to 210 kPa. ISO 1135-4 design and test requirements do not match this performance and in particular omit testing under negative pressure. Transfusion sets surveyed did not indicate flow or pressure restrictions or specify the blood components with which they had been validated. ISO 1135-4 requires updating and has been initiated. Meanwhile, recommendations are made for transfusion set manufacturers concerning pressure limitations and restrictions on blood component type and for users concerning purchase, configuration and validation of infusion pumps and disposables.

The aim of this study was to establish a simple and reproducible antegrade perfusion method for isolating single viable mouse heart cells and to determine the standard practical protocols that are appropriate for mice of various ages. Antegrade perfusion was performed by injecting perfusate from near the apex of the left ventricle of the excised heart, the aorta of which was clamped, using an infusion pump. This could thoroughly perfuse the myocardium through the coronary circulation. All procedures were carried out on a prewarmed heater mat under a microscope, which allows for the processes of injection and perfusion to be monitored. With appropriate adjustment of the size of the injection needle, the composition and amount of enzyme solution and the perfusion flow rate, this antegrade perfusion method could be applied to the hearts of neonatal to aged mice. We examined the morphological characteristics and electrophysiological properties of the isolated ventricular and atrial myocytes and found that these cells were mostly identical to those obtained with the traditional Langendorff‐based retrograde perfusion method. Interstitial nonmyocytes, such as cardiac progenitor cells, were also isolated simultaneously from the supernatant fraction of the centrifugation, similar to the retrograde perfusion method. The results suggest that single heart cells can be well isolated with high degree of quality by the present antegrade perfusion method, regardless of the age of the mouse.

Summary Objectives: Although remifentanil has been used to induce hypotension during surgery in infants, no pharmacokinetic–pharmacodynamic (PKPD) model exists for its quantitative analysis. Our aim was to determine the quantitative relationship between whole blood remifentanil concentration and its hypotensive effect during surgery in infants. Methods/materials: We studied seven infants (age 0.3–1 year) who underwent cranioplasty surgery and received remifentanil delivered by a computer-controlled infusion pump during the maintenance of anesthesia. Arterial blood samples to determine remifentanil concentration and mean arterial blood pressure (MAP) measurements were collected. A simultaneous PKPD mixed-effects model was built in NONMEM. Results: A total of 77 remifentanil concentrations and 185 MAP measurements were collected. Remifentanil pharmacokinetics was described with a two-compartment model, parameter estimates were 2.99 l·min−1·70 kg−1 for clearance and 16.23 l·70 kg−1 for steady state volume of distribution. Mean baseline MAP was 69.7 mmHg and was decreased as per clinical requirements. A sigmoidal Emax model driven by an effect compartment described the decrease in MAP, with an estimated concentration to decrease MAP by half (EC50) being 17.1 ng·ml−1. Conclusions: Remifentanil is effective in causing hypotension. The final model predicts that a steady state remifentanil concentration of 14 ng·ml−1 would typically achieve a 30% decrease in MAP.

Aim: The purposes of this study are to describe the occurrence of long fixation in view points during infusion pump operation and to examine if there are any differences in the visual behavior between students and nurses or between operating the infusion pump with and without an alarming sound. Methods: The participants consisted of six nursing students and three nurses with clinical experience. In a simulated patient room, the participants were equipped with eye trackers and asked to perform two scenarios of infusion pump operation: changing the i.v. tubing position and the air bubble alarm. The eye movement indicators were analyzed statistically with two-way ANOVA (clinical experience and the alarming sound were the fixed factors). Results: Long fixations appeared frequently at the critical part of the infusion pump operation. The students significantly fixated more frequently and had more long fixations than the nurses. In particular, the students frequently fixated to the manual roller clamp. The eye movement indicators were not significantly different between the two scenarios, but the air bubble alarm scenario had a larger ratio of time fixating to the i.v. tubing and a smaller ratio of time fixating to the patient. Conclusion: In this study, a large difference could be seen in the comparison of visual behavior by clinical experience. It was clear that the students carefully tried to check each critical point as they were not used to infusion pump operation. It also was found that, although the nurses had relatively consistent eye movement, the students did not grasp the checkpoints and the positions of fixation were dispersed easily as a consistent nursing procedure had not been established.

We report a case of intrathecal baclofen infusion pump implantation complicated by migration of the catheter tip. A 55-year-old man required an intrathecal baclofen infusion for severe spasticity 4 years after a cervical spinal cord injury with incomplete tetraparesis. Twelve months after initial implantation of the device, the patient began to experience a recurrence of trunk tightness and spasticity. Subsequent X-ray and computed tomography evaluations of the catheter system revealed pooling of contrast medium outside of the intrathecal distribution in the lumbar subcutaneous region of the back and therefore migration of the pump catheter tip. At surgical revision, emphasis was placed on minimizing the length of catheter outside of the spine and securing the catheter in the supraspinous fascia with a right-angled anchor. The distance between the anchors and the entry point of the catheter into the supraspinous fascia was also reduced to prevent slipping when the patient bends forward. After surgery, the patients spasticity improved and, 1 year later, he has experienced no further complications during follow-up, requiring an average baclofen dose of 150 microg/day. Here, we describe several surgical methods intended to secure the intrathecal catheter and prevent catheter migration. Other complications related to catheter failure are also highlighted.

Aims and objectives. This study sought to assess the impact of a standardized protocol to maintain nasoenteral tube (NET) patency in patients requiring fluid restriction and identify factors associated with tube patency. Background. Nasoenteral tube obstruction may interrupt nutritional support and prohibit drug administration. Balancing NET patency in the context of fluid restriction can be a challenge. Design and methods. The impact of the standardized protocol was assessed by using a quasi-experimental design and an historical control. Results. Sixty patients receiving nasoenteral feeding as part of their clinical management were enrolled in the study. Nasoenteral obstruction was 8·3%, showing a reduction from the 17·4% observed in the baseline data collection. A key factor associated with tube obstruction was sounding of an infusion pump alarm reflecting the tube patency issues. Conclusions. While mindful of the limitations of probability sampling, the implementation of a standardized protocol accompanied by staff training reduced the rates of NET obstruction. Relevance to clinical practice. On the basis of these findings, we conclude that it is possible to maintain the patency of small bore tubes, even in the presence of fluid restriction, with a standardized protocol to guide clinical management.

Background: Inadvertent intraneural injection of local anesthetics may result in neurologic injury. We hypothesized that an intraneural injection may be associated with higher injection pressures and an increase in the risk of neurologic injury. Methods: The study was conducted in accordance with the principles of laboratory animal care, and was approved by the Laboratory Animal Care and Use Committee. Fifteen dogs of mixed breed (16–21 kg) were studied. After general endotracheal anesthesia, the sciatic nerves (n= 30) were exposed bilaterally. Under direct vision, a 25-gauge, long-beveled needle (30°) was placed either epineurally (n= 10) or intraneurally (n= 20), and 4 ml of preservative-free lidocaine 20 mg/ml was injected using an automated infusion pump (4 ml/min). Injection pressure data were acquired using an in-line manometer coupled to a computer via an analog-to-digital conversion board. After injection, the animals were awakened and subjected to serial neurologic examinations. One week later, the dogs were killed, the sciatic nerves excised and histologic examination was performed by pathologists blind to the purpose of the study. Results: All perineural injections resulted in low pressures (≤ 5 psi). In contrast, eight of 20 intraneural injections resulted in high pressures (20–38 psi) at the beginning of the injection. Twelve intraneural injections, however, resulted in pressures of less than 12 psi. Neurologic function returned to baseline within 3 h after perineural injections and within 24 h after intraneural injections, when the measured injection pressures were less than 12 psi. Neurologic deficits persisted throughout the study period after all eight intraneural injections that resulted in high injection pressures. Histologic examination of the affected nerves revealed fascicular axonolysis and cellular infiltration. Conclusions: The data in our canine model of intraneural injection suggest that intraneural injections do not always lead to nerve injury. High injection pressures during intraneural injection may be indicative of intrafascicular injection and may predict the development of neurologic injury.

Regular self-infusion of an activated prothrombin complex concentrate (APCC) has been successfully introduced to a 14-year-old boy with hemophilia A. The child was diagnosed as a neonate, and at age 7 years, developed a high titer (127 BU/mL) factor VIII inhibitor coincident with a protracted ankle joint bleeding. From age 7-10 years, he received on-demand therapy using a prothrombin complex concentrate (PCC), PROPLEX-ST. From age 10-14 years, he received prophylaxis with PROPLEX-ST, initiated after an intracranial hemorrhage and coincident anamnestic inhibitor response. Throughout 7-year period of PCC treatment, he experienced recurrent bleeding episodes. Self-prophylaxis with APCC, FEIBA VH [Anti-inhibitor Coagulant Complex] (50 U/kg/dose three times per week) using infusion pump was initiated at 14 years of age and has continued for 2 years. There were no bleeding, thrombotic events or other adverse events after initiation of this prophylaxis, and inhibitor levels decreased to 1 BU/mL. His quality of life was improved, particularly with respect to school. Our long observation proposes a well-disciplined home-based FEIBA prophylaxis in inhibitor-positive hemophiliacs.

Background: Continuous ambulatory analgesia following various surgical procedures is gaining popularity. The purpose of the present paper is to evaluate this form of analgesia following open anterior inguinal hernia repair by way of a pain control infusion pump (PCIP). Methods: Forty-eight consecutive patients scheduled for inguinal hernia repair were enrolled in a double-blind, randomized, placebo-controlled trial. Following the repair, a catheter was placed in the wound connected to an external PCIP, delivering either ropivacaine or normal saline at a fixed rate of 4 mL/ h. Regular 4-hourly postoperative pain observations according to a Visual Analogue Score (VAS) and any rescue opioid requirements were recorded, at different levels of mobility. Results: Data analysis included 23 (ropivacaine) and 24 (saline) patients in each group, with one exclusion. There were no adverse effects of the PCIP in either group. Patients in the ropivacaine group (‘active pump’) had lower mean pain scores and less rescue analgesia compared to the saline group (‘placebo pump’). This clinical effect was found to be more striking at increased levels of mobility. Importantly, no patients in the ropivacaine group required any rescue analgesia after the first 4-h block postoperatively. Conclusion: The PCIP provided safe and adequate analgesia following inguinal hernia repair. It provided effective analgesia especially when patients were mobilizing. This has implications for earlier discharge from hospital and associated cost-savings.

The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 ± 0.60 mm2 between MetriCath and QCA, 0.13 ± 0.55 mm2 between MetriCath and IVUS, and 0.22 ± 0.80 mm2 between IVUS and QCA. This corresponds to 6.2% ± 10%, 3.0% ± 9.0%, and 3.1% ± 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r = 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted. Cathet Cardiovasc Intervent 2002;57:2–9. © 2002 Wiley-Liss, Inc.

Background: Awake fiberoptic intubation is the standard of care for difficult airway management. Quality and success of this technique depend on the experience of the intubating physician and the proper preparation of the patient. The aim of this study was to compare remifentanil (R) as single agent to the combination of fentanyl (F) and midazolam (M), which have been the drugs for analgesia and sedation for this procedure. Methods: Seventy-four adult patients requiring nasotracheal intubation were randomly assigned to one of two groups. In group I, (n=37) R was administered in incremental dosages (0.1–0.25–0.5 µg/kg/min) by an infusion pump according to comfort, level of sedation and respiratory depression. In group II, (n=37) analgesia and sedation was achieved by F 1.5 µg/kg and doses of between 1 and 10 mg M, titrated to the individual needs. Patient reactions like grimacing, movement and coughing during intubation were assessed, as well as patient recall of the procedure. Haemodynamic and respiratory parameters were continuously recorded. Results: Group I patients better tolerated nasal tube passage (P

Background Blood sampling from arterial lines is a frequent event in anesthesia and critical care. To avoid clot formation, both the stopcock outlet and the cannula must be flushed after sampling. We investigated in a bench experiment whether fluid flow through the cannula is affected by the sequence of flushing procedures. Methods Continuity of fluid delivery from a vascular cannula was gravimetrically determined using two different flushing techniques with either a syringe pump flush system or a bag flush system. The procedures comprised first flushing the stopcock towards the cannula and then towards the stopcock sampling outlet or the reverse order. Experiments were repeated in triplicate and two sets for each flushing system at hydrostatic pressures of 37 mm Hg and 74 mm Hg. Results The main finding of the study was that flushing the stopcock towards the outlet after flushing the cannula resulted in considerable retrograde aspiration volumes and zero flow times, in particular in combination with syringe pump flush systems. At a hydrostatic pressure of 74 mm Hg, the observed zero flow time at the cannula tip amounted to (mean+/-SD) 0.1+/-0.01 min with the bag flush system and 7.7+/-0.5 min with the syringe pump flush system. The related retrograde aspiration volumes were 2.2+/-0.7 microl with the bag system and 30.0+/-2.0 microl with the syringe pump system. No backflow was recorded when the stopcock was first flushed to ambient pressure and then afterwards towards the cannula. Conclusion Opening a flush system to ambient pressure affects the continuity of fluid delivery, particularly when using syringe pump flush systems. After blood sampling, the stopcock outlet should be flushed first followed by cannula flushing.

BACKGROUND Ambulatory infusion pumps are used to deliver concurrent chemotherapy with pelvic radiation therapy for patients with rectal carcinoma. The pump is worn around the waist and may be exposed to direct as well as scattered radiation, possibly leading to a complete malfunction, requiring a new pump, and/or changes in the pump timing, with clinically significant reductions in chemotherapy administration. METHODS Two new ambulatory chemotherapy pumps were irradiated using a 6-megavolt linear accelerator. The first pump received gradually increasing doses to determine whether a complete malfunction were possible and the approximate dose. The second pump was irradiated with a single large dose of 20 Gray (Gy) followed by smaller doses of 2 Gy to characterize the dose better. After each dose of radiation was given to both pumps, an internal self-diagnostic test and an independent assessment of the pump timing were performed. RESULTS The first pump malfunctioned completely at a cumulative dose of 38.6 Gy after receiving an individual dose of 20 Gy. The second pump tolerated the single dose of 20 Gy without difficulty and completely malfunctioned at doses of 40–42 Gy. The second pump exhibited a reduction in pump timing by 25% at a cumulative dose of 40 Gy, which resolved spontaneously by approximately 2 hours. CONCLUSIONS Even if removed from the direct radiation beam, an individual pump could accumulate enough radiation for complete failure during the treatment of fewer than 20 patients. Prior to a complete malfunction, the flow rate of chemotherapy may decrease by 25% for a number of hours without detection. Additional work will be necessary to define further the nature of the reduction in pump timing observed. Cancer 1999;86:2150–3. © 1999 American Cancer Society.

BACKGROUND Reports of in vitro experiments in colorectal carcinoma cells suggest that prolonged cellular exposure to 5-fluorouracil (5-FU) combined with relatively low concentrations of leucovorin (LV) provides optimal enhancement of 5-FU efficacy. In this study, a simplified regimen of weekly 24-hour infusion of high dose 5-FU combined with a relatively low dose of LV was used to treat patients with advanced colorectal carcinoma. METHODS Thirty-six patients with advanced colorectal carcinoma received 5-FU, 2600 mg/m2, admixed with LV, 100 mg/m2, in a portable infusion pump administered intravenously over a 24-hour period. High dose 5-FU/LV was delivered once a week for 5 consecutive weeks followed by a 1-week recovery period. All patients were assessable for toxicity and response. RESULTS Two complete responses and 15 partial responses were observed (response rate of 47.2%; 95% confidence interval, 30.1-64.4%). The median response duration was 9.6 months. The median survival and time to progression were 11.9 months and 7.1 months, respectively. The toxicity was mild and acceptable. The major dose-limiting factors were hand-foot syndrome and fatigue. CONCLUSIONS This simplified regimen of weekly 24-hour continuous infusion of high dose 5-FU/LV is an effective regimen in the treatment of patients with advanced colorectal carcinoma. Further study of the pharmacokinetics of combination therapy with 5-FU and LV as used in this regimen and its correlation with response and toxicity is warranted. Cancer 1999;85:1925–30. © 1999 American Cancer Society.

The 'Diprifusor' target controlled infusion system has been developed as a standardised infusion system for the administration of propofol by target controlled infusion. A preferred set of pharmacokinetic parameters for propofol was selected using computer simulation of a known infusion scheme with pharmacokinetic parameters described in published literature. The selected model was included in a 'Diprifusor' module that was interfaced with, and later incorporated into, a computer-compatible infusion pump. Clinical trials with such systems led to guidance on appropriate target concentrations for the administration of propofol by 'Diprifusor' target controlled infusion for inclusion in drug prescribing information. Standardisation of the delivery performance (+/- 5%) of commercial systems has been achieved with a laboratory performance specification. Clinical studies indicate that the actual blood concentrations achieved were about 16% greater than the calculated values displayed by the system. In an individual patient, titration of the target concentration is required in the same manner as an anaesthetic vapouriser is adjusted to obtain a specific pharmacodynamic effect.

The availability of fast-acting intravenous drugs for anaesthesia has encouraged anaesthetists to gain a practical understanding of the pharmacodynamics and pharmacokinetics of these drugs to optimise their administration. 'Diprifusor' technology uses pharmacokinetic modelling to control the infusion rate of a pump, providing the anaesthetist with direct control of the blood concentration rather than indirect control by the infusion rate. The 'Diprifusor' electronics module is a dual microprocessor component that can be incorporated into an infusion pump to provide this mode of administration. This paper describes the module's infusion control system, prefilled syringe recognition system and the safety aspects addressed by the design.

The purpose of this in vitro study was to determine whether the Gemini PC-2TX infusion pump could safely deliver peripheral stem cells (PSC) for an autologous PSC transplant. For purposes of hypothesis testing, it was assumed that there would be no significant difference in CD34+ cell counts and colony-forming units-granulocyte, macrophage (CFU-GM) when the PSCs were administered by an IMED PC-2TX infusion pump as opposed to an intravenous push method. The American Red Cross collected 50-ml samples of PSCs from four donors by apheresis. These cells were tested for CD34+ using flow cytometry and for functional progenitor cells using a CFU-GM assay. The cells were cryopreserved after testing. For our study, samples were tested simultaneously at a single facility. Each sample was individually thawed and a baseline thaw sample collected; 10 ml of the donor specimen was pushed through a syringe into a specimen container (intravenous push sample). The remainder of the specimen was infused through the IMED Gemini PC-2TX pump into a specimen container (intravenous pump sample). All samples were assayed for CD34+ cell counts and CFU-GM. Data analyses were conducted using the t-test for paired samples, with values of P < 0.05 considered significant. Results failed to demonstrate a statistically significant difference between the CD34+ or CFU-GM results of the intravenous push and intravenous pump specimens. Additionally, we failed to find a statistically significant difference when we compared the intravenous push and the intravenous pump specimens with the baseline thaw sample. The results of this study support the hypothesis that the Gemini PC-2TX infusion pump can safely deliver PSCs for the purposes of stem cell transplantation.

Background: The development of venous access devices (VADs) and portable infusion pumps has enabled chemotherapy to be administered continuously within the home environment. Aim: The objective of this study was to describe the experience of establishing an ambulatory chemotherapy programme for patients receiving protracted infusions (PVIs) of 5-fluorouracil (5-FU). Methods: The files of all patients receiving PVI 5-FU as a component of their treatment for gastrointestinal malignancy were reviewed. The types of VADs, infusion pump systems and their management were documented. Information packages and education programmes were developed for patients. Results: Seventy-four patients with gastrointestinal cancer were studied. At the end of the review period the Portacath was the preferred VAD, while both pumps used were found to have advantages and disadvantages. The choice of pump was decided more by patient preference than systematic differences in performance of the pumps. Conclusions : The findings in this review confirm that, with close attention to the potential pitfalls of ambulatory chemotherapy, an acceptable service can be provided.

As the primary users of medical devices in direct patient care, registered nurses must be competent both with simple and complex devices because any device improperly used can have serious consequences. Results of a cross-sectional survey of registered nurses (n = 238) working at a large South Australian tertiary care centre on units with high usage both of indwelling urethral (Foley) catheters and intravenous infusion pumps revealed that participants were significantly more likely to have learned to use the indwelling urethral (Foley) catheter in nursing school than they were to have learned how to use an intravenous infusion pump. Participants differed significantly on most (13 of 17) items about what they learned, with nurses being more likely to learn various factors about the indwelling urethral catheter than the infusion pump. Registered nurses were more likely to feel stressed when using an intravenous infusion pump than when using an indwelling urethral catheter, but were more likely to have used an indwelling urethral catheter that caused a patient harm than an intravenous infusion pump that caused a patient harm. The most frequently identified reasons for incidents of patient harm resulting from use of an intravenous infusion pump were user error and inadequate device education. The most frequently identified reasons for incidents of patient harm resulting from use of an indwelling urethral catheter were the patient's condition, particularly confusion, user error, equipment malfunction, and inadequate device education.

Purpose: There are a number of commercially available flow phantoms for evaluating Doppler ultrasound systems. However, it may be hard to justify purchasing these phantoms if a hospital has a small number of ultrasound units to evaluate. In this study, we developed a simple flow phantom with parts available in a hospital to evaluate Doppler ultrasound systems. Methods: To create a flow reserve, one end of an IV line was connected to a 100 ml saline bag and the line was filled with saline. 20 ml of glycerin was injected into the saline bag to simulate blood like flow characteristics. The other end of the IV line was also connected to the saline bag to create a loop. The IV line was fed into an infusion pump (programmable up to 999 ml/hr) and was also placed between a uniform ultrasound phantom and a standoff gel pad. To minimize impedance differences, acoustic gel was used between the phantom and the gel pad. Doppler measurements were performed on two Philips iU22 ultrasound units using the L12-5 probes. Results: The pulsatile flow of the solution in the IV line could be seen in the Doppler mode when the infusion pump was running. The color Doppler also indicated the direction of the flow via overlaid red or blue color on the grayscale B-mode ultrasound image of the IV line. The directionality of the flow could be confirmed by reversing the direction of the probe. The peak flow rates (cm/s) observed on the waveforms were reproducible within %10 when the measurements were repeated. Conclusion: A simple flow phantom can be developed from materials available in a hospital for routine evaluation of Doppler ultrasound systems.

Objective: DISE is increasingly being used to localize the obstructive site in OSAS patients. The objective of this study is to determine if propofol changes sleep parameters in polysomnography.Method: Thirty subjects (6 controls/24 with OSAS) underwent 2 diurnal polysomnographies, with/without the use of propofol, controlled by target-controlled infusion pump (Diprifusor). The examinations were compared regarding the presence of snoring, AHI, oxygen desaturation, and sleep architecture. Endoscopies with the patients sleeping and awake were also compared.Results: The use of propofol did not induce snoring in the control subjects, whereas 100% of the OSAS patients snored. Propofol increased N3 sleep and abolished totally REM sleep (P2 did not differ significantly between the 2 examinations (P > .05). The minimum SaO2 were significantly reduced during propofol sedation.Conclusion: Propofol changed the sleep architecture, but not the main respiratory parameters in OSAS. DISE was shown to be safe and more rel...

Parenteral compounds present special drug delivery challenges. This open-label study evaluated a portable infusion pump as a means to deliver intravenous ciprostene, a stable prostacyclin analog. Ten patients with peripheral vascular disease and claudication received ciprostene (titrated to 120 ng/kg/min) infused over 8 hours 1 day per week for 4 consecutive weeks. Patients successfully maintained the pump strapped to the waist. The mean +/- standard deviation delivery error, with volumes of 6 to 10 mL over 8 hours, was -0.895 +/- 3.177%. Accordingly, the pump performed well with a potent drug under these clinical conditions. Headache, flushing, and infusion site irritation during infusion were the most frequent side effects. Blood pressure remained unchanged during infusion; however, heart rate increased significantly (P < .05, maximum increase was 13.9 +/- 2.1 beats per minute [mean +/- standard error of the mean]. Mean (+/- standard error of the mean) relative claudication times on treadmill remained unchanged; however, absolute claudication times increased (P < .05) from 6.6 +/- 1.8 to 10.0 +/- 2.2 minutes. Ciprostene inhibited adenosine diphosphate-induced platelet aggregation by 56.0 +/- 12.7% (mean +/- standard error of the mean). Mean template bleeding times and plasma concentrations of platelet-specific proteins (beta-thromboglobulin, platelet factor 4) did not change.