Search

Mechanical stress on red blood cells is associated with using infusion pumps for blood administration. Current standards in North America leave it to healthcare facilities to consult with manufacturers about infusion pump safety for transfusion; studies on various pumps and red blood cell (RBC) conditions are scarce.RBC units were pumped through four infusion pumps on d22 (22 days postcollection), d40, d28 after gamma irradiation on d14 (I14d28), and d22 after irradiation on d21 (I21d22). For each experiment, three units were pooled and split among four bags. Samples were collected at gravity and after pumping at clinical nonemergency rates. Hemolysis %, microvesicles, potassium, lactate dehydrogenase, mechanical fragility index levels, and morphology evaluations were performed (n = 5-6).Hemolysis levels of Piston and Linear Peristaltic pump samples were not different from hemolysis of corresponding gravity samples. Peristaltic samples had significantly higher hemolysis compared to gravity, and other pumps, however, maximum mean difference was limited to 0.05%. Pumping at 50 mL/h resulted in the highest hemolysis level. Change in hemolysis % due to pumping was significantly higher in d40 and I21d22 units. No combination of pumps and RBCs conditions led to hemolysis0.8%. Besides hemolysis, lactate dehydrogenase release was the only marker that demonstrated some differences between infusions via pump versus gravity.The pump design affects the degree of hemolysis. However, for all tested pumps and RBC conditions, this increase was minimal. Hemolysis measurement on d40 and I21d22 at 50 mL/h were concluded to be appropriate parameters for pump evaluation.

Portable infusion pumps are an interesting solution to continue outpatient parenteral antimicrobial therapy (OPAT) at the patient's home. However, the use of ceftazidime for such applications is challenging in view of its relatively poor stability in solution. In this study, elastomeric infusion pumps with 6 or 7 g of ceftazidime were deflated over 24 h in an oven at 33°C while ceftazidime and its degradation product, pyridine, were regularly monitored. Hereto, a fast and sensitive liquid chromatographic (LC) method has been developed using a Kinetex® C18 (150 × 3 mm, 2.6 μm) column with gradient elution. Ammonium formate 20 mM and acetonitrile (ACN) were mixed in a ratio of 98:2 v/v for mobile phase A and 85:15 v/v for mobile phase B. Both were adjusted to pH 4.5 with formic acid. The flow rate was set at 0.4 mL/min. The solution with a starting dose of 6 g ceftazidime was found to be degraded 10% after an average of 19 h 11 min so that an administration of 6 g to the patient was not reached. For the solution with a starting dose of 7 g of ceftazidime, 10% degradation was observed after an average of 18 h 42 min. However, by starting from a higher dose, an average of 6.56 g of ceftazidime could be administered over 24 h. In addition, 1.0% of pyridine versus ceftazidime pentahydrate with sodium carbonate (=mixture for injection) was formed over 24 h.

Introduction: Continuous glucose monitoring (CGM) provides detailed information about glucose level fluctuations over time. The method is increasingly being used in pregnant women with type 1 diabetes. However, only one previous study compared CGM results related to pregnancy outcomes in women using insulin pumps with those administering multiple daily injections (MDI). We performed a secondary analysis of CGM metrics from an observational cohort of pregnant women with type 1 diabetes and compared insulin pump and MDI therapies in relation to maternal and neonatal outcomes. Material and methods: The study included 185 pregnant Swedish women with type 1 diabetes undergoing CGM throughout pregnancy. Women were divided according to insulin administration mode, ie MDI (n = 131) or pump (n = 54). A total of 91 women used real-time CGM and 94 women used intermittently viewed CGM. Maternal demographics and maternal and neonatal outcome data were collected from medical records. CGM data were analyzed according to predefined glycemic indices: mean glucose; standard deviation; percentage of time within, below and above glucose target range; mean amplitude of glycemic excursion; high and low glucose indices; and coefficient variation in percent. Associations between insulin administration mode and CGM data, on the one hand, and maternal and neonatal outcomes, on the other, were analyzed with analysis of covariance and logistic regression, respectively, adjusted for confounders. Results: There were no differences in maternal characteristics or glycemic indices between the MDI and pump groups, except for a longer duration of type 1 diabetes and higher frequencies of microangiopathy and real-time CGM among pump users. Despite improvement with each trimester, glucose levels remained suboptimal throughout pregnancy in both groups. There were no differences between the MDI and pump groups concerning the respective associations with any of the outcomes. The frequency of large for gestational age was high in both groups (MDI 49% vs pump 63%) and did not differ significantly. Conclusions: Pregnant women with type 1 diabetes did not differ in glycemic control or pregnancy outcome, related to MDI or pump administration of insulin. Glycemic control remained suboptimal throughout pregnancy, regardless of insulin administration mode. (Less)

BACKGROUND CalliSpheres are drug-eluting beads used for tumor artery embolization, with clinical benefits in a number of cancer types. The aim of the study was to examine the clinical benefits and complications of patients with stage II-IV lung cancer treated with CalliSpheres drug-eluting beads for embolization versus conventional vascular interventional treatment. METHODS This was a prospective cohort study conducted from August 2018 to May 2019. The patients were grouped according to traditional bronchial arterial infusion chemotherapy (infusion group) or bronchial arterial chemoembolization with CalliSpheres drug-eluting beads loaded with adriamycin (CallisSphere group). Short-term effects, serum tumor markers, and adverse reactions during follow-up were compared between the two groups. RESULTS There were 60 participants enrolled into the study with 30 in each group including 54 men and six women, 42-78 years of age. In the CalliSphere group, compared with the infusion group, the disease control rate was 93.3% versus 73.3% (P = 0.080) and the objective remission rate (ORR) was 86.7% versus 60.0% (P = 0.039); the three- and six-month progression-free survival (PFS) and six-month overall survival (OS) were better in the CalliSphere group (three-month PFS: 96.7% vs. 73.3%, P = 0.026; six-month PFS: 87.5% vs. 57.1%, P = 0.045; six-month OS: 87.5% vs. 52.7%, P = 0.024); after treatment, the tumor markers in the CalliSphere group were lower (CEA: P

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.

In 2017, the World Health Organization published “Medication Without Harm, WHO Global Patient Safety Challenge,” to reduce patient harm caused by unsafe medication use practices. While the five objectives emphasise the need to create a framework for action, engaging key stakeholders and others, most published research has focused on the perspectives of health professionals. The aim was to explore the views and experiences of decision-makers in Qatar on organisational safety culture, medication errors and error reporting. Method: Qualitative, semi-structured interviews were conducted with healthcare decision-makers (policy-makers, professional leaders and managers, lead educators and trainers) in Qatar. Participants were recruited via purposive and snowball sampling, continued to the point of data saturation. The interview schedule focused on: error causation and error prevention; engendering a safety culture; and initiatives to encourage error reporting. Interviews were digitally recorded, transcribed and independently analysed by two researchers using the Framework Approach. Results: From the 21 interviews conducted, key themes were the need to: promote trust within the organisation through articulating a fair blame culture; eliminate management, professional and cultural hierarchies; focus on team building, open communication and feedback; promote professional development; and scale-up successful initiatives. There was recognition that the current medication error reporting processes and systems were suboptimal, with suggested enhancements in themes of promoting a fair blame culture and open communication. Conclusion: These positive and negative aspects of organisational culture can inform the development of theory-based interventions to promote patient safety. Central to these will be the further development and sustainment of a “fair” blame culture in Qatar and beyond. The authors wish to acknowledge the contributions of all interviewees, as well as support departments at Hamad Medical Corporation, Doha, Qatar. The study was supported by NPRP grant NPRP 7‐388‐3‐095 from Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The publication of this article was funded by the Qatar National Library.

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.

Technologic advances in the past century have led to the ability to safely deliver parenteral nutrition (PN) to hospitalized patients. Key breakthroughs included the development of saline and glucose infusions, infusion pumps, macronutrients (lipids, dextrose, and amino acids), and central venous catheters. In the 1960s, centrally delivered PN was performed in short-term hospitalized patients by Lincoln James Lawson (North Staffordshire Royal Infirmatory, United Kingdom) and long-term patients by Stanley Dudrick (University of Pennsylvania, United States). These early studies showed that a system was needed that would allow patients with intestinal failure to be discharged from the hospital and receive home PN (HPN). In the late 1960s and early 1970s, Belding Scribner, Maurice Shils, Khursheed Jeejeebhoy, Marvin Ament, Dudrick, and their teams discharged patients from the hospital who then self-administered HPN. Shortly after these early cases of HPN, multidisciplinary centers were established first in North America, and later in Europe, to manage these complex cases. The current article describes the patients treated by these early HPN pioneers, in addition to subsequent case series reported by them and others.

Although smart infusion pumps are intended to prevent medication errors by alerting users about doses that exceed set thresholds, a large number of clinically insignificant alarms and alerts create the potential for alert and alarm fatigue. We searched the PubMed, Scopus, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases for peer-reviewed literature (January 1, 2004-August 31, 2017) on managing smart pump alerts, alarms, and related fatigue. Twenty-nine articles that met the inclusion criteria were reviewed and organized into themes. Smart pumps give users two types of signals: alarms that indicate mechanical issues such as occlusion, air in the line, or low battery; and clinical alerts that indicate that a programmed dose exceeds a predefined safety limit. Mechanical alarms occur with greater frequency than clinical alerts, but alarms and alerts vary widely by pump model, patient population, time of day, month, and type of drug. Several causes of clinically insignificant alerts and alarms may be actionable, and strategies proposed in the literature include development of a multidisciplinary team to oversee the quality improvement effort with involvement of end users, standardization of medication administration practices, widening of drug limit library thresholds when clinically appropriate, maintaining up-to-date drug limit libraries, and interoperability. Whereas many strategies have been proposed, and case studies have been reported, none have been rigorously evaluated. In addition, more research is needed related to managing occlusion and air-in-line alarms, especially for complicated infusions. Future work should focus on the evaluation of specific and replicable alert and alarm reduction strategies with a greater emphasis on quantitative metrics.

Continuous epidural infusions are an effective and safe method of providing anesthesia and postoperative analgesia in infants and children with multiple advantages over systemic medications, including earlier tracheal extubation, decreased perioperative stress response, earlier return of bowel function, and decreased exposure to volatile anesthetic agents with uncertain long-term neurocognitive effects. Despite these benefits, local anesthetic toxicity remains a concern in neonates and infants because of their decreased metabolic capacity for amide local anesthetics. Chloroprocaine, an ester local anesthetic agent, which is rapidly metabolized in plasma at all ages, is an attractive alternative for this special population, particularly in the presence of superimposed liver impairment or when higher infusion rates are needed for surgical incisions stretching many dermatomes. The current manuscript reviews the literature pertaining to the use of 2-chloroprocaine for regional anesthesia in infants and children. Dosing regimens are presented and the applications of 2-chloroprocaine in this population are discussed.

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 Enteral nutrition therapy is common practice in pediatric clinical settings. Often patients will receive a pump-assisted bolus feeding over 30 minutes several times per day using the same enteral feeding set (EFS). This study aims to determine the safest and most efficacious way to handle the EFS between feedings. METHODS Three EFS handling techniques were compared through simulation for bacterial growth, nursing time, and supply costs: (1) rinsing the EFS with sterile water after each feeding, (2) refrigerating the EFS between feedings, and (3) using a ready-to-hang (RTH) product maintained at room temperature. Cultures were obtained at baseline, hour 12, and hour 21 of the 24-hour cycle. A time-in-motion analysis was conducted and reported in average number of seconds to complete each procedure. Supply costs were inventoried for 1 month comparing the actual usage to our estimated usage. RESULTS Of 1080 cultures obtained, the overall bacterial growth rate was 8.7%. The rinse and refrigeration techniques displayed similar bacterial growth (11.4% vs 10.3%, P = .63). The RTH technique displayed the least bacterial growth of any method (4.4%, P = .002). The time analysis in minutes showed the rinse method was the most time-consuming (44.8 ± 2.7) vs refrigeration (35.8 ± 2.6) and RTH (31.08 ± 0.6) ( P < .0001). CONCLUSIONS All 3 EFS handling techniques displayed low bacterial growth. RTH was superior in bacterial growth, nursing time, and supply costs. Since not all pediatric formulas are available in RTH, we conclude that refrigerating the EFS between uses is the next most efficacious method for handling the EFS between bolus feeds.

Outpatient pain management after iliac crest bone harvesting can be challenging. We report the use of home L2 paravertebral nerve block catheter (L2PVBC) in a series of five children. The pain scores were low, and analgesic medication consumption was minimal. No complications were reported related with these catheters, and the patients reported very high pain control satisfaction scores. Outpatient L2PVBC can be beneficial as part of a multimodal analgesia strategy in selected pediatric patients.

The aim of our in-vitro study was to assess the impact of infusion set characteristics on the accuracy of morphine doses in patient-controlled analgesia. Two infusion sets differing in conception and dead-space volume were assessed: a standard set and a low dead-space volume Y-set. The patient-controlled analgesia programme parameters were as follows: bolus equal to 1 ml at 100 ml.h(-1) ; lockout intervals equal to 5 and 10 min; and carrier fluid flow rate equal to 10 and 50 ml.h(-1) . Morphine concentration was determined by an ultraviolet spectrophotometric method. The morphine doses were significantly different from one set to the other during bolus and lockout intervals, whatever the patient-controlled analgesia programme. The average doses were approximately 1.3-6.0 times higher with the low dead-space volume Y-set during bolus. Our study underlines the impact of infusion set characteristics on the accuracy of morphine patient-controlled analgesia doses.

This study seeks to identify the delivery method of continuous infusion using a 250 cc IV bag via pump, change every 8 h. Additionally, the study will examine the infection risk with the use of 8 h infusions. Ten hemophilia A patients were identified for the study. Each patient received a bolus factorVIII (FVIII) infusion with a pre FVIII level and 1 h post FVIII level to determine recovery levels for optimal dosing. On the day of 8-h continuous infusion, the pt received a bolus VIII (Kogenate FS (™)) for correction to 100% followed by individually calculated continuous infusion (Kogenate FS (™)) FVIII. FVIII levels were drawn from the IV bag and peripherally from the patient in the opposite arm at time points: pre infusion, 1, 2, 3, 4, 5, 6 and 8 h. Additionally, blood cultures were drawn from the IV bag and from the IV tubing at time points pre infusion, 4 and 8 h. Fourteen subjects agreed to participate in the study; 4 failed to follow up, hence 10 subjects were included in the analysis of data; 7 severe, 2 moderate, and 1 mild hemophilia A. Age range was 26-62 years. Ethnic breakdown included 5 African American, 4 Caucasian, 1 Hispanic. With all infusions, the range of FVIII was 65-135% (blood) and 62-200% (bag). After the start of infusion, there were no significant differences noted between the hourly FVIII levels in the subjects and the IV values (P-value range 0.36-0.9). Additionally, given three time points with six cultures per patient, totaling 60 points of cultures drawn for the study, all cultures from the IV bag and patient were negative. The effective delivery method and safety of an 8-h continuous infusion of FVIII (Kogenate FS (™)) has been confirmed. This method can be helpful given that many hospitals may not carry the required mini-pumps, allowing a standard safe delivery of FVIII (Kogenate FS (™)) continuous infusion by available means.

Objective Oxygen delivery, underpinned by vascular tone, is the principle limiting factor in the study of skeletal muscle physiology, particularly during muscle contraction. The aim of this study was to develop an autologous perfused rat hind limb preparation for the study of skeletal muscle contractile function. Methods Adult Wistar rats were surgically prepared using a by-pass system for pump-controlled arterial blood flow to, and venous return from the hind limb during periods of quiescence and twitch contraction of the gastrocnemius-plantaris-soleus muscle bundle. Results During rest, hind limb perfusion pressure (102 ± 5 mmHg) was not different to systemic arterial pressure (99 ± 4 mmHg). Hind limb pressure was responsive to vasoconstrictors and vasodilators (±50 mmHg). The arterial PO2 (100 ± 3 mmHg), O2 saturation, and acid–base balance (pH: 7.42 ± 0.01) contributed to resting hind limb (a-v)O2 difference (4.8 ± 0.5 mL/100 mL) and VO2 (0.31 ± 0.03 μmol/g/min wet weight). Repetitive isometric twitch tension (1 Hz, 0.05 ms, 10 minutes) was best maintained at a flow rate of 2 mL/min (VO2 increased fivefold during muscle contraction) and efficiency of oxygen use increased from 0.27 ± 0.08–0.52 ± 0.07 N/μmol/min. Conclusion The autologous rat hind limb provided resting vascular tone allowing maintenance of perfusion pressure at flows within the physiological range. Oxygen delivery supported repetitive twitch contractions and facilitated measurement of active metabolism.

SummaryAim To provide an overview of factors influencing the flow rate in intravenous (IV) therapy for newborns. Methods We conducted a review of the literature from 1980 to 2011 in PubMed and Web of Knowledge. Articles focusing on flow-rate variability and possible complications due to flow-rate variability were included. Results Forty-one articles were selected for this review. IV therapy in (preterm) neonates is prone to significant start-up delays and flow-rate variability. The sudden changes in the volume delivered to (preterm) neonates may have serious consequences. Low preprogrammed flow rates, total compliance, and volume of the IV administration set, the presence or absence of antisiphon valves or inline filters and the vertical displacement of syringe pumps all contribute to flow-rate variability in IV therapy for neonates. Conclusions Flow-rate variability in IV therapy and its clinical relevance are due to the preprogrammed flow rate, the hydrostatic pressure changes, the complete IV administration set compliance and the type of substances supplied to the patient. To improve IV therapy, the internal compliance of the complete IV administration set should be minimized and the highest possible preprogrammed flow rate should be used in combination with small syringes and low-resistance valves.

Secretion of glucocorticoids is widely known as a key endocrine response to stresses. Prenatal dexamethasone administration induces intrauterine growth retardation and delayed onset of puberty in female rats independent of the hypothalamic Kiss1-gonadotropin-releasing hormone (GnRH) system. The aim of this study was to evaluate the influence of chronic intracerebroventricular (central, CD) or subcutaneous (peripheral, PD) dexamethasone administration to prepubertal female rats on the onset of puberty and body weight change. Rats administered dexamethasone from day 25 to day 34 (CD and PD) showed significantly reduced body weight gain throughout the experimental period and delayed onset of vaginal opening compared with rats administered saline centrally (CS) or peripherally (PS). At 34 days old, hypothalamic Kiss1r mRNA levels were significantly lower with CD than with CS. No significant differences were seen between rats administered saline and rats administered dexamethasone with regard to hypothalamic Kiss1, GnRH and NPY mRNA levels or serum LH levels. Serum leptin concentrations were higher in CD and PD than in the controls (CS and PS). These results suggest that the delayed onset of puberty induced by prepubertal dexamethasone administration occurs independent of the hypothalamic Kiss1-GnRH system.

Background: Nafamostat mesilate (NM), a protease inhibitor, is available for acute pancreatitis and disseminated intravascular coagulopathy and is used as an anticoagulant for haemodialysis in Japan. Co-infusion of red cell concentrates (RCC) and intravenous drugs is usually contraindicated. Because of limited venous access, adherence to the guidelines may be compromised in some clinical settings. Therefore, we investigated the influence of co-infusion of RCC and various anticoagulants on haemolysis in vitro. Methods: We investigated the effect of co-incubation of RCC and various anticoagulant drugs [NM, gabexate mesilate (GM), heparin] in packed erythrocytes. We evaluated haemolysis using lactate dehydrogenase and free haemoglobin. In addition, we also evaluated the influence of co-incubation on phosphatidylserine (PS) expression on the erythrocyte membrane. Results: GM and NM induced haemolysis in a dose-dependent manner, which was inhibited by removal of citrate and pretreatment with the calcium chelator, ethylenediaminetetraacetic acid. In a dynamic experiment using an infusion pump, NM not only induced haemolysis during co-infusion with RCC but also elevated PS expression dependent on extracellular calcium. Conclusion: NM and GM induce haemolysis in packed erythrocytes in the presence of citrate that is dependent on extracellular calcium.

Objective To compare the quality of intrathecal baclofen obtained from a national compounding pharmacy (AnazaoHealth) with the manufactured product (Lioresal) with regard to accuracy and precision of baclofen concentration, and the content of the baclofen degradation product, 4-(4-chlorophenyl)-2-pyrrolidinone (PYR). Design Samples of baclofen used for refilling intrathecal pumps were placed in 1.2-mL silicone gasket–sealed cryogenic vials and stored at or lower than −25°C. Each sample was a different lot number (Lioresal) or prescription number (AnazaoHealth). The laboratory was blinded to the source of the solutions. Coupled with electrospray ionization-mass spectrometry analyte confirmation, quantitation of baclofen and PYR in each sample was performed in duplicate by using high-performance liquid chromatography with ultraviolet detection via a photodiode array detector. Setting Outpatient clinic. Participants Patients with intrathecal baclofen pumps. Main Outcome Measures Accuracy and precision of baclofen concentration, and concentration of PYR. Results The difference of mean concentrations from expected concentrations of 500 and 2000 μg/mL were significantly greater for samples from AnazaoHealth compared with Lioresal. Values are shown as mean (± standard error), with n the number samples, for AnazaoHealth compared with Lioresal: (537.1 ± 6.7 μg/mL [n = 8] versus 515.6 ± 0.82 μg/mL [n = 5]; P = .034, respectively) and (2211.4 ± 21.6 μg/mL [n = 12] versus 2055.3 ± 8.7 μg/mL [n = 4]; P = .004, respectively). AnazaoHealth samples with expected concentration of 4000 μg/mL were 3987.7 ± 79.9 μg/mL, n=7. All 9 Lioresal samples were within 5% of the expected concentration. Of 27 AnazaoHealth samples, 22 were more than 5%, and 8 were more than 10% different from the expected concentration. No PYR was detected in any sample from AnazaoHealth. All samples of Lioresal contained PYR, but all solutions contained less PYR than 1% of the baclofen concentration. Conclusions Lioresal was more accurate in concentration and more precise among batches than compounded intrathecal baclofen but had higher levels of PYR.

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.

A 21-year-old male with sickle cell disease (SCD) presented with severe pallor. He had received a total of 100 red blood cell (RBC) units in his lifetime, had a mean serum ferritin level of 3133 ng/ml, and liver iron concentration (LIC) of 12 mg Fe/g dry weight (dw). He was started on subcutaneous deferoxamine (DFO) infusions at a dose of 56 mg/kg/d, five days a week (equivalent to 40 mg/kg/d, seven days a week) and continued to receive 8–10 RBC units/year as treatment for pain. During the first six months of chelation therapy, his serum ferritin levels fell by around 50% of the pretreatment value, but then started to increase back up to the baseline values. The patient was noncompliant with DFO therapy. He experienced pain at the site of injection, could not sleep and was concerned about carrying a pump and not being accepted by his peers. He dropped out of college and abstained from all social activities. He was referred to a psychologist; however, this failed to improve compliance and he opted to stop DFO therapy altogether.

Twenty-seven women who had clomiphene-resistant anovulation as the only cause of infertility were studied. They were divided into 2 groups on the basis of pre-treatment endocrine and ultrasound assessment: hypogonadotropic hypogonadism (HH) (N=6) and polycystic ovarian disease (PCOD) (N=21). They were administered pulsatile luteinizing hormone releasing hormone (LHRH) therapy using miniaturized portable infusion pumps at a constant dose 15 ug per pulse every 90 minutes. The patients with HH were treated for a total of 31 cycles and 4 pregnancies were obtained. Twenty-eight out of 31 cycles of therapy were ovulatory. The patients with PCOD were treated for a total of 65 cycles and, of these, 40 cycles were ovulatory. Ten patients became pregnant. When the patients with PCOD who ovulated were compared with those who failed to ovulate, it was found that the only predictor of successful therapy was the ponderal or body mass index. The mean ponderal index of those who ovulated was 22.20±2.62 (±SD) compared with 26.01±0.81 (±SD) for those who remained anovulatory. We conclude that pulsatile LHRH therapy is efficacious therapy for patients with HH but not as effective for patients with PCOD. In the latter group the ponderal index predicts for the likelihood of successful response to therapy.

We previously showed different effects of tobacco and nicotine on fracture healing, but due to pump reservoir limits, maximum exposure period was 4 weeks. To allow flexibility in pre- and post-fracture exposure periods, the objective of this study was to compare a new oral administration route for nicotine to the established pump method. Four groups were studied: (1) pump saline, (2) pump saline + oral tobacco, (3) pump saline/nicotine + oral tobacco, and (4) pump saline + oral nicotine/tobacco. Sprague–Dawley rats (n = 84) received a transverse femoral fracture stabilized with an intramedullary pin 1 week after initiating dosing. After 3 weeks, no difference was found in torsional strength or stiffness between oral nicotine/tobacco or pump nicotine + tobacco, while energy absorption with oral nicotine/tobacco was greater than pump nicotine + tobacco (p

For several years, total intravenous anesthesia (TIVA) has demonstrated many advantages that allow consideration of propofol anesthesia as an interesting alternative in pediatric anesthesia. TIVA in children requires calculation and validation of pharmacokinetic (PK) models specifically adapted to the pediatric population. Several PK models based on a 3-compartment approach have been proposed in children: all these models, which integrate only weight as covariable, show increased distribution volumes with a wide interindividual variability. However, as pharmacodynamic (PD) parameters are still debated in children, there is up to now, no PKPD model currently available for pediatric anesthesia. The particular importance to include physiological covariables, as size and age, to describe metabolic processes during growth and maturation in pediatric PKPD models is in agreement with recent allometric scaling works in children. The Schnider's model, a model described in adults that includes numerous covariables, may be adapted and more efficient than the classical pediatric model to describe propofol-PKPD relationship in children over 5 years. Whatever is the model, a pharmacodynamic feed back such as the bispectral index may be useful to counteract the interindividual variability in the pediatric population.

Factor VIII (FVIII) replacement by continuous infusion (CI) is used postoperatively or after significant bleeding. For young paediatric patients, CI may require FVIII dilution. Variable stabilities of diluted full-length recombinant FVIII Kogenate FS (KG-FS) have been reported under different storage conditions. We investigated the recovery and stability of diluted KG-FS in vitro and in vivo. Kogenate FS was diluted to 50-120 U mL(-1) and its recovery and stability in glass vials or polypropylene syringes was determined. Furthermore, stability of KG-FS diluted to 80 U mL(-1)'administered' via single- and double-pump mock CI systems was tested. Finally, the in vivo stability of KG-FS diluted to approximately 60 U mL(-1) and administered postsurgically by CI with the double-pump to a paediatric patient with severe haemophilia A undergoing implantable venous access device placement was investigated. Initial KG-FS dilution resulted in a 10-20% FVIII loss; a further 25-30% loss occurred over 72 h in vials or syringes. With the double-pump, 1 h recovery was 35%, increasing to 80% by 24 h; the initial losses were because of the Y-infusion of a 10-fold larger volume of saline concomitantly with the FVIII. In vivo, CI resulted in stable FVIII activity levels within the target range. These in vitro results are important for the generation of CI guidelines for diluted KG-FS in the paediatric haemophilic population. That FVIII losses occur upon dilution and with the double-pump does not preclude use of diluted KG-FS. Indeed, stable FVIII levels were maintained when diluted KG-FS was administered by CI with the double-pump to a paediatric patient postsurgically.

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.

Adjuvant-induced arthritis in rats shares many of the features of humans with rheumatoid arthritis, including the development of osteopenia in areas distal to erosive joint disease. We established adjuvant arthritis in male and female Sherman strain rats and then studied external calcium balances and vitamin D metabolism during the period of acute active clinical, serologic, and pathologic arthritis and osteopenia and in the preclinical period. While ingesting a calcium-sufficient vitamin D-replete diet (0.6% calcium, 0.65% phosphorus, and 2.2 IU D3 per g food), female rats with arthritis demonstrated reduced calcium balance (arthritic, 36 + 8 versus control, 169 + 13 mg per 6 days, p < 0.02) because of inefficient gastrointestinal absorption of calcium (arthritic 9.7% versus control 37%). This was associated with calcitriol deficiency (arthritic 52 + 7 versus control 70 + 10 pg/ml) and reduced osteocalcin levels. Male rats with arthritis demonstrated an inability to raise serum calcitriol levels to the same degree as control rats (200 + 30 versus 440 + 70, respectively) while ingesting a calcium-deficient diet (0.002% calcium, 0.34% phosphorus, and 2.2 IU D3 per g food) and also had reduced balance (59 + 7 versus 85 + 10 mg per 6 days, respectively) due in part to decreased efficiency of absorption (55 versus 67%). No abnormalities in calcium balance or in serum calcitriol levels on the sufficient diet were present in the preclinical period. Physiologic calcitriol replacement to arthritic female rats increased osteoid available for mineralization and increased mineral apposition rates. Calcitriol deficiency in adjuvant-induced arthritis is responsible, in part, for reduced calcium balance and likely contributes to the development of osteopenia during the acute stage of the systemic inflammatory disease.

Female nude mice were infused with 5.0, 3.0, or 1.0 micrograms/day of synthetic human parathyroid hormone-related protein (PTHrP) or control diluent with subcutaneous Alzet miniosmotic pumps for 7 days. Serum calcium was increased (p less than 0.01) on days 3 (13.9 mg/dl), 5 (13.6 mg/dl), and 7 (12.9 mg/dl) in mice infused with PTHrP at 5.0 micrograms/day compared with control nude mice (8.8 mg/dl). Serum calcium was significantly increased to a lesser degree in mice infused with 1.0 micrograms/day PTHrP (day 3) or 3.0 micrograms/day (days 3 and 7). Serum phosphorus was decreased (p less than 0.01) in all three groups of mice infused with PTHrP (4.6 mg/dl, 5.0 micrograms/day; 6.7 mg/dl, 3.0 micrograms/day; and 6.4 mg/dl, 1.0 micrograms/day) compared with controls (8.5 mg/dl). Serum 1,25-dihydroxycholecalciferol was increased (2.4-fold) in mice infused with PTHrP (5.0 and 3.0 micrograms/day). The urinary calcium-creatinine ratio (0.74 compared with 0.034 in controls) was increased (p less than 0.03) in mice infused with PTHrP (5.0 micrograms/day), but the urinary phosphorus-creatinine ratio was not different from that in controls. The urinary cAMP-creatinine ratio was increased (1.6-fold) in mice infused with PTHrP (5.0 micrograms/day). Static bone histomorphometry revealed increased (p less than 0.01) trabecular bone area, osteoblast perimeter, osteoid perimeter, osteoid width, wall width, osteoclast area, number of osteoclasts, and osteoclast perimeter in trabecular bone of lumbar vertebrae from mice infused with PTHrP. Dynamic bone histomorphometry demonstrated increased (p less than 0.01) double-labeled perimeter, mineralizing perimeter, and bone formation rate. The results of this study indicated that PTHrP increased serum calcium and 1,25-dihydroxycholecalciferol, decreased serum phosphorus, increased urinary excretion of calcium, phosphorus, and cAMP, and increased both bone resorption and formation in nude mice. PTHrP mimics the action of native PTH in vivo and is likely to be an important protein in the pathogenesis of humoral hypercalcemia of malignancy.

Calcium absorption declines with age. Because 1,25-dihydroxyvitamin D (1,25(OH)2D) is the major hormone controlling calcium absorption, changes in vitamin D metabolism may account for the malabsorption of aging. Serum levels of 1,25(OH)2D have been reported to either decrease or remain unchanged with age. To assess the effect of aging on renal production of 1,25(OH)2D, we evaluated the response of renal 25OHD 1 alpha hydroxylase to human parathyroid hormone (hPTH(1-34) stimulation in 119 women ages 25-83 years. In this population, baseline serum 25OHD and 1,25(OH)2D values did not significantly change with age, but serum iPTH (r = 0.44; p < 0.001) and serum creatinine (r = 0.31; p < 0.01) increased with age. However, the stimulatory activity of hPTH(1-34) on the renal production of 1,25(OH)2D declined with age (r3 = -0.36; p < 0.001) and was most apparent after age 75, being 50% less than that of younger women. Besides age, the production of 1,25(OH)2D was found to be dependent on baseline serum iPTH (r = -0.31; p < 0.0001). Administration of hPTH(1-34) led to suppression of endogenous PTH, and suppressibility of endogenous PTH declined with age (r = 0.53; p < 0.0001). The increase in serum PTH and decreased suppressibility of PTH with age could be due to mild secondary hyperparathyroidism. The increase in PTH with age is probably responsible for maintaining normal serum 1,25(OH)2D levels in elderly subjects; however, decreased metabolism of 1,25(OH)2D in the elderly could also maintain normal serum 1,25(OH)2D levels.

Ambulatory local anaesthetic delivery systems are often limited by a short effective duration of infusion. Prolonging nerve blockade by substituting a new pump as recommended by the manufacturers, represents a substantial consumable item cost ($US 300-500). We therefore evaluated the flow delivery performance of 31 single model elastomeric devices (all with a 2 ml.h(-1) background and 5 ml every hour bolus capability) that had been filled, used in clinical practice and then refilled in the laboratory. For the second infusion, there was a pattern of over-infusion (< 10 ml.h(-1)) in the first hour; however, all pumps depreciated to < 150% of predicted by the second hour. The subsequent performance of all pumps was not only within safe limits, but also predominantly within the range (background infusion +/- 15%, bolus +10/-20%) specified by the manufacturer for primary infusion. We conclude that this elastomeric regional anaesthesia pump design performs satisfactorily after having been refilled following a single previous use.

Intravenous enzyme replacement therapy with recombinant human α-L-iduronidase (rhIDU) is used weekly to treat mucopolysaccharidosis (MPS) I. We tested continuous administration of rhIDU at two dosing levels (0.58 mg/kg per week and 2 mg/kg per week) in MPS I dogs, and compared the efficacy of continuous infusion with the clinically used 0.58 mg/kg weekly three-hour infusion. Peak plasma concentrations of rhIDU were much higher in weekly-treated dogs (mean 256 units/ml) than steady-state concentrations in dogs treated with continuous infusion (mean 1.97 units/ml at 0.58 mg/kg per week; 8.44 units/ml at 2 mg/kg per week). Dogs receiving continuous IV rhIDU, even at a higher (2 mg/kg per week) dose, had consistently lower iduronidase levels in tissues than dogs receiving a weekly (0.58 mg/kg per week) dose. GAG storage was also less improved by continuous intravenous infusion. Adverse events were similar in all dosing groups. We found that continuous administration of 2 mg/kg per week rhIDU to MPS I dogs was insufficient to achieve GAG storage reduction comparable to 0.58 mg/kg weekly dosing.

Objective: To assess the skills of advanced emergency medicine trainees in the use of commonly used transport equipment and to determine what teaching has been undertaken and what level of confidence trainees have in their ability to use the equipment tested. Methods: This is a prospective multicentre observational study examining equipment use. Three pieces of equipment were examined: the infusion pump, defibrillator-monitor and transport ventilator. A questionnaire and a series of practical tasks were used. Advanced trainees from Victorian ED were enrolled as participants. Outcomes included proportion of participants able to perform all tasks successfully, subjective registrar confidence with use of equipment and departmental training practices. Eleven ED were represented, covering metropolitan tertiary, metropolitan peripheral and regional hospitals. Results: There were 47 participants enrolled in the study. The range of advanced training years of participants was 1–5+. Of the 47 participants, 39 (83%; 95% CI 72.2–93.7%) had been involved as medical escorts. Eighteen participants (38.3%; 95% CI 24.4–52.2%) described some form of teaching for equipment use. The median level of confidence of participants (on a 5-point scale) was 4 (25–75% interquartile range 3–4), which correlates with a moderate degree of confidence. Of 47 participants, 7 (14.9%; 95% CI 4.7–25.1%) rated themselves as not confident or somewhat under-confident (i.e. 1 or 2 on the scale). Of 47, 12 passed overall (25.5%; 95% CI 13.1–38%) and 8 completely failed (17.0%; 95% CI 6.3–27.8%) the skill testing. Conclusion: When tested in isolation, there appears to be deficits in the equipment skills of advanced ED trainees who are expected to be proficient in transport medicine.

Hyperpolarized 3He magnetic resonance imaging (MRI) NEED TO INTRODUCE TERM, UNLESS YOU ARE OVER THE WORD COUNThas been recently used to produce high-resolution images of pulmonary ventilation after methacholine challenge in mouse models of allergic inflammation. This capability presents an opportunity to gain new insights about these models and to more sensitively evaluate new drug treatments in the pre-clinical setting. In the current study, we present our initial experience using two-dimensional, time-resolved 3He MRI of methacholine challenge-induced airways hyperreactivity to compare ovalbumin-sensitized and challenged (N=8) mice to controls (N=8). Imaging demonstrated that ovalbumin-sensitized and challenged animals exhibited many large ventilation defects even prior to methacholine challenge (4 out of 8) compared to no defects in the control animals. Additionally, the ovalbumin sensitized and challenged animals experienced a greater number of ventilation defects (4.5±0.4) following methacholine infusion than did controls (3.3±0.6). However, due to variability in methacholine delivery that was specific to the small animal MRI environment, the difference in mean defect number was not statistically significant. These findings are reviewed in detail and a comprehensive solution to the variability problem is presented that has greatly enhanced the magnitude and reproducibility of the methacholine response. This has permitted us to develop a new imaging protocol consisting of a baseline 3D image, a time-resolved 2D series during methacholine challenge, and a post-methacholine 3D image that reveals persistent ventilation defects.

Mouse models of MPTP intoxication have been used extensively to explore the molecular mechanisms of Parkinson's disease. However, these models present some limitations since; (i) Dopaminergic (DA) cell death occurs rapidly in contrast to the presumably slow evolution of the disease process. (ii) Some of the key histological features of the disease such as Lewy body like inclusions and long-term inflammatory changes are lacking. Fornai et al. [Proc. Natl Acad. Sci. USA 102 (2005), 3413] suggested that continuous delivery of MPTP with Alzet osmotic minipumps may possibly circumvent these problems. Our results show, however, that MPTP infusion via Alzet osmotic minipumps (40 mg/kg/day) produces only a transient depletion in striatal dopamine (DA) without causing dopaminergic cell loss in the substantia nigra. Neuronal cell loss occurred, however, if MPTP was infused concomitantly with probenecid, an uricosuric agent which potentiates the effects of the toxin injected via the i.p. route. Even under these conditions, dopaminergic cell loss was moderate (-25%) and other neurodegenerative changes characteristic of Parkinson's disease remained undetectable.

The source of hemolysis during hemodialysis must be quickly identified to avoid life-threatening complications. At a single clinic, over a 10-day period in which 550 treatments were performed, 5 case-patients were retrospectively identified for experiencing acute hemolysis (4 deaths) from an unknown origin. The investigation focused on the postpump arterial tubing as the pressure was not monitored in this region, and the segment was shorter than required and could kink if overly stressed at bend points (i.e., tubing support clips, dialyzer inlet). To determine whether the circuit pressures indicated kinked tubing, a relative comparison between each case-patient's recorded arterial (prepump) and venous circuit pressures throughout their adverse event treatment and their immediately preceding treatment was conducted. Treatment pressure-time traces showed that sustained, significant decreases (>25 mmHg) in both of the circuit pressures occurred only on the hemolytic event dates. While direct observations of kinked tubing were not reported, the circuit pressure decreases could only be explained by severe postpump tube kinking causing a decrease in the blood flow rate. While postpump obstructions and hemolysis can occur without causing noticeable changes to the prepump arterial and venous blood line pressures (due to the highly occlusive setting of the roller blood pump), recognizing sudden and/or sustained decreases in the circuit pressures during treatment may help to prevent adverse patient events. This analysis reinforces the importance of regularly checking the blood tubing set for kinks and for monitoring the circuit pressures for atypical trends within and between treatments.

Summary Purpose: This multicenter, double-blind, double-dummy, randomized, inpatient trial evaluated the safety, tolerability, and pharmacokinetics of intravenous lacosamide as replacement for oral lacosamide in patients with partial-onset seizures. Methods: Patients were enrolled from an ongoing open-label extension trial of oral lacosamide and randomized (2:1) to either intravenous lacosamide and oral placebo or intravenous placebo and oral lacosamide. During the 2-day inpatient treatment period, patients received twice-daily doses of lacosamide equivalent to their current daily dose of oral lacosamide. The first 30 patients enrolled received infusions with 60-min durations and the next 30 received infusions with 30-min durations. Results: Of 60 patients randomized, 59 completed the trial. Treatment-emergent adverse events (AEs) were reported by 16 patients and included dizziness, headache, back pain, somnolence, and injection site pain. The tolerability profile of intravenous lacosamide was consistent with that of oral lacosamide. All AEs were considered mild or moderate in intensity, and no serious AEs or AEs leading to withdrawal were reported. Conclusions: Intravenous lacosamide, administered as 60- or 30-min twice-daily infusions, showed a similar safety and tolerability profile to oral lacosamide when used as replacement therapy. Results from this trial support further investigation of intravenous lacosamide at shorter infusion durations.

We conducted an open-label, parallel-group study of the high purity, mass-produced recombinant human serum albumin (rHSA), derived from the methylotrophic yeast Pichia pastoris, to compare pharmacokinetics and ensure bioequivalence with plasma-derived human serum albumin (pHSA) in 22 patients with liver cirrhosis. Both rHSA and pHSA groups enrolled 11 patients each, assigned according to predose serum albumin concentrations using the minimization method. Pharmacokinetic and safety profiles for 3-day repeated intravenous infusions at a daily dose of 25 g were evaluated for 8 days. Geometric mean AUC(0-168hr) (g.hr/dL) was 637.12 and 635.93 in the rHSA and pHSA groups, respectively, with a 90% confidence interval (CI) for the difference (92.9%-108.1%) lying within the bioequivalence range. The other major parameter, geometric mean C(max) (g/dL), was 4.16 and 4.19 in the rHSA and pHSA groups, respectively, with a 90% CI for the difference (92.7%-106.4%). The pHSA group presented with 3 adverse events: 1 case of insomnia, and 2 laboratory abnormalities with no serious adverse events. Results from this study show similar pharmacokinetic profiles following intravenous administration of 25g/day of rHSA and pHSA for 3 days, indicating bioequivalence.

Objective. The grafting of human scalp hair was used as a new application of this method to explore methyl mercury incorporation into human hair and to validate this model for mercury monitoring in hair. Methods. Human scalp grafts were transplanted to athymic BALB/c nude mice. The animals were exposed to methyl mercury either as a single dose i.p. or continuously for 4 months, using ALZET osmotic pumps. The mercury concentration in hair was determined using x-ray fluorescence (XRF) spectrometry by segmental (2 mm) analysis of a single strand, and tissue concentrations were measured by cold vapor atomic absorption analysis. Results. Human scalp hair grown in nude mice showed long-term persistence of human features including the expression of histocompatibility antigens (KAB 3, W 6/32, SF 1-1.1.1) and normal hair morphometry. The disposition of methyl mercury in nude mice followed a one-compartment model with a whole body elimination half-life of 6.7 days (elimination constant, k = 0.1/day). Autoradiographic studies revealed that methyl mercury was rapidly incorporated into areas of the hair follicle undergoing active keratinization. Methyl mercury concentrations in human hair transplanted onto nude mice were two orders of magnitude higher than in blood and attained a mean hair: blood ratio of 217 : 1, similar to ratios reported only in human studies. Conclusions. This study demonstrated that human hair grown on nude mice can record the level of exposure to methyl mercury and can serve as a valuable research tool to study mercury incorporation into human hair. Copyright © 2007 John Wiley & Sons, Ltd.

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.

The aim of this study was to assess the performance in terms of red cell damage of two peristaltic volumetric infusion pumps - the Alaris IVAC 572 (San Diego, CA, USA) and Arcomed Volumed VP7000 (Regensdorf, Switzerland). Various infusion pumps are available to transfuse blood at a predetermined rate. It is recommended that each machine should be individually assessed. This experiment used six units of single-donor-transfusable packed red cells and ran each unit through both pumps. This was carried out at 9, 28 and 35 days post-donation at rates from 2 to 150 mL h(-1). Post-pumping samples from these experiments, and a pre-pumping sample in each case, were analysed for levels of potassium and free haemoglobin (Hb). They were also examined microscopically for evidence of cell damage. Potassium levels showed no significant change with pumping on any occasion, but rose significantly as the samples aged. Free Hb showed some variation, but the only consistent finding was a similar rise in value with increasing pack age. Microscopic examination revealed no cell damage under any condition. Both pumps performed to an acceptable level and appear safe to be used for red cell transfusion.