Low-dose Heparin Research Articles

Pharmacokinetic Analysis of Continuous Intravenous Infusion of Lipo-Prostaglandin E1 As a Prophylaxis of Hepatic Veno-Occlusive Disease after Hematopoietic Stem Cell Transplantation

Introduction: Prostaglandin E1 (PEG1) has various pharmacological effects such as vasodilation, inhibition of platelet aggregation, inhibition of superoxide anion generation, activation of the fibrinolytic system and inhibition of vascular smooth muscle cell proliferation. Continuous intravenous infusion of PGE1 as a prophylaxis of hepatic veno-occlusive disease (VOD) in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) have previously been shown to be effective. Further study has been done with continuous intravenous infusion of lipo-prostaglandin E1 (lipo-PGE1) because it can be used in smaller doses to avoid toxicities since it is a form of PGE1 dissolved in the lipid emulsion of soybean oil and thus has greater and long lasting effects. However, it has not been evaluated pharmacokinetically.Methods: We performed a prospective explorative pharmacokinetic study on patients who received continuous intravenous infusion of lipo-PGE1 at a dose of 1mcg/kg/day as a prophylaxis of VOD during HSCT at Seoul National University Children's Hospital. Eligible patients were those at high risk of developing VOD (previous abdominal irradiation, liver function abnormality, busulfan or total body irradiation based conditioning, age under 18 years old) but who cannot use low dose heparin due to low platelet count, bleeding tendency or allergy. Dose of lipo-PGE1 could be increased to 1.5mcg/kg/day if patients showed clinical symptoms of VOD, before the establishment of VOD diagnosis. Lipo-PGE1 level was measured before the start of infusion (B level), between 1 hour and 72 hours after the start of infusion (P1 level), and after neutrophil engraftment (P2 level). Additional samplings were done if the dose of infusion was changed or if the condition of the patient changed significantly. Patients were evaluated for the occurrence and severity of VOD. VOD was diagnosed without limitation of onset time, when patients had 2 or more of the following features: serum total bilirubin of greater than 2 mg/dL, hepatomegaly or right upper quadrant pain of liver origin, or unexplained weight gain of greater than 2% over baseline.Results: Thirty patients were enrolled between January 2015 and May 2016 and all of them were eligible for analysis. Patients underwent HSCT at median age of 12.2 years old for hematologic malignancies, solid tumors, brain tumors, and non-malignant diseases. Donors and stem cell sources were variable. Twenty patients received busulfan-based conditioning and 1 patient received total body irradiation based conditioning. Continuous intravenous infusion of lipo-PGE1 was started at median 1 day before the start of the conditioning regimen and was administered for a median duration of 29 days (range, 23-56 days). Dose of lipo-PGE1 was adjusted to 1.5mcg/kg/day in 2 patients at median 18 days (range, 14-21 days) from start of continuous infusion due to increasing serum total bilirubin or tender hepatomegaly. B level and P1 level were measured in all enrolled patients and P2 level was measured in all 28 of the patients who achieved neutrophil engraftment. The P1 level was 6.60 ± 2.88 (mean ± standard deviation) pg/mL and the clearance was 308.48 ± 233.04 L/h. The P2 level was significantly lower than P1 level at 5.55 ± 2.06 pg/mL (P=0.005) and the clearance was greater at 392.64 ± 302.78 L/h but it was not statistically significant (P=0.109). The coefficient of variability (CV%) of lipo-PGE1 level and clearance were 43.64% and 75.54% respectively at P1 and 37.12% and 77.11% respectively at P2. Between-subject variability of lipo-PGE1 level and clearance (11.18 and 51.65 %) were higher than intra-subject variability (7.19 and 7.40 %). No significant relationship was found between the level or clearance of lipo-PGE1 and occurrence or severity of VOD. VOD developed in 2 patients (6.7%) but both resolved completely with antithrombin-III based treatment at median 38 days from diagnosis. There was no adverse event or death related to lipo-PGE1 prophylaxis and there were no deaths related to VOD.Conclusions: We herein provide the first prospective explorative pharmacokinetic data of continuous infusion of lipo-PGE1 as a prophylaxis of VOD in patients undergoing HSCT. We also suggest that lipo-PGE1 is efficient and safe as a prophylaxis of VOD in patients undergoing HSCT. DisclosuresNo relevant conflicts of interest to declare.

Role of Low Molecular Weight Heparin (LMWH) in the Treatment of Recurrent Missed Abortion

Objective (s): The aim of this study was to explore the outcome of treatment of low molecular weight heparin (LMWH) in recurrent missed abortion cases.Method: This prospective observational study was done between January 2005 and July 2014 in Infertility Care and Research Center, Dhaka, Bangladesh. Two hundred and ten (210) patients who were able to give clear history of missed abortion, who had no endocrine and hypertensive disorders and who conceived spontaneously or after fertility treatment were the target population for this study. After positive pregnancy test all patients started taking oral progesterone (Dydrogesterone 10 mg bd), folic acid and aspirin 75 mg daily. Patients were advised to come for ultrasonography at 6 weeks of pregnancy. After confirming intrauterine viable pregnancy by ultrasonography we started injection enoxaparin (LMWH) 40 mg sc daily to all patients and continued till 34 completed weeks. The primary end point was the live birth rate and secondary end points were the side effects, late pregnancy complications and neonatal outcome in the study population.Results: One hundred and nine (52.39%) patients had antiphospholipid syndrome. Among them antiphospholipid subgroup antibody found in 40.37% cases, ACLA found in 27.52% cases, LA found in 18.34% cases and both ACLA and LA found in 13.77% cases. Antinuclear antibody was positive in 10% cases. No abnormality was identified in 38.09% cases. Pregnancy continued successfully in 96.66% cases. There were no maternal and foetal complications. Except failed cases there was no need to discontinue the treatment.Conclusion: This observational study dealt only with recurrent missed abortion and found satisfactory outcome with low dose heparin therapy. Large, well-designed randomized trials are needed to establish the heparin therapy in recurrent missed abortion.Bangladesh J Obstet Gynaecol, 2014; Vol. 29(2) : 94-101

Mesenchymal stromal cell secretomes are modulated by suspension time, delivery vehicle, passage through catheter, and exposure to adjuvants

Background aimsExtensive animal data indicate that mesenchymal stromal cells (MSCs) improve outcome in stroke models. Intra-arterial (IA) injection is a promising route of delivery for MSCs. Therapeutic effect of MSCs in stroke is likely based on the broad repertoire of secreted trophic and immunomodulatory cytokines produced by MSCs. We determined the differential effects of exposing MSCs to different types of clinically relevant vehicles, and/or different additives and passage through a catheter relevant to IA injections. MethodsMSCs derived from human bone marrow were tested in the following vehicles: 5% albumin (ALB), 6% Hextend (HEX) and 40% dextran (DEX). Each solution was tested (i) alone, (ii) with low-dose heparin, (iii) with 10% Omnipaque, or (iv) a combination of heparin and Omnipaque. Cells in vehicles were collected directly or passed through an IA catheter, and MSC viability and cytokine release profiles were assessed. ResultsCell viability remained above 90% under all tested conditions with albumin being the highest at 97%. Viability was slightly reduced after catheter passage or exposure to heparin or Omnipaque. Catheter passage had little effect on MSC cytokine secretion. ALB led to increased release of angiogenic factors such as vascular endothelial growth factor compared with other vehicles, while HEX and DEX led to suppression of pro-inflammatory cytokines such as interleukin-6. However, when these three vehicles were subjected to catheter passage and/or exposure to additives, the cytokine release profile varied depending on the combination of conditions to which MSCs were exposed. DiscussionExposure of MSCs to certain types of vehicles or additives changes the profile of cytokine secretion. The activation phenotype of MSCs may therefore be affected by the vehicles used for these cells or the exposure to the adjuvants used in their administration.

Efficacy and safety of prehospital administration of unfractionated heparin, enoxaparin or bivalirudin in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: Insights from the ORBI registry

Despite numerous studies in recent years, the best anticoagulant option for primary percutaneous coronary intervention (PCI) remains a matter of debate. To compare in-hospital outcomes after prehospital administration of low-dose unfractionated heparin (UFH)±glycoproteinIIb/IIIa inhibitors (GPIs), enoxaparin±GPIs, or bivalirudin in patients undergoing primary PCI for ST-segment elevation myocardial infarction (STEMI). A total of 1720patients (median age 62.0years, 79.2% male) who had been enrolled in a prospective registry and received an injectable anticoagulant in physician-staffed mobile intensive care units before primary PCI were included in the study. The main outcomes were in-hospital major adverse cardiovascular events (MACE) (a composite of all-cause mortality, non-fatal myocardial infarction, stroke or definite stent thrombosis) and in-hospital major bleeding (Bleeding academic research consortium type3 or 5). UFH was administered in 420 (24.4%) patients, enoxaparin in 1163 (67.6%) patients and bivalirudin in 137patients (8.0%). Rates of in-hospital MACE were 7.4% with UFH, 6.0% with enoxaparin and 6.6% with bivalirudin, with no significant differences between groups (P=0.628). In-hospital major bleeding occurred in 1.7% of patients on UFH, 1.4% on enoxaparin and 1.5% on bivalirudin (P=0.851). By multivariable analysis, the prehospital anticoagulant used was not an independent predictor of MACE or major bleeding. In this prospective registry, there were no significant differences in the rates of in-hospital MACE or major bleeding after prehospital initiation of UFH, enoxaparin or bivalirudin in patients treated by primary PCI for STEMI.

Case report of a patient who delivered in our hospital being received low dose aspirin and heparin at a distant clinic

The typical placebo response (ie, the nonspecific effects in the placebo group including benign natural course, regression to the mean, expectation/conditioning effects, and others) in randomized trials in complex regional pain syndrome (CRPS) is unknown. We recently observed a surprising near-absence of placebo response in a randomized controlled trial we conducted on patients with long-standing (≥6 months) CRPS. To investigate the idea that there may be an absence of placebo response in long-standing CRPS further, we conducted a systematic review and meta-analysis of placebo responses in randomized controlled trials conducted in patients with CRPS of ≥6 months. We systematically identified suitable randomized controlled trials published between 1966 and September 2013. We calculated the mean difference and standard error of the mean difference for placebo responses and synthesized individual effect sizes at 4 specified time periods of interest (15–30 minutes, 1 week, 3–4 weeks, and 6 weeks or more) via meta-analysis using the method of inverse-variance. Heterogeneity was assessed according to the I2 statistic. For primary analysis, we pooled trial-specific effect sizes over the 4 time points. We analyzed data from 340 participants from 18 trials out of a possible 361 participants from 20 trials (94% of participants analyzed). Significant heterogeneity was present between trials; therefore, we interpreted trends from visual inspection of individual trials and pooled estimates. Placebo response was significant at the earliest time period (15–30 minutes). There was no significant evidence of placebo response at any of the other time periods. These results inform the design of future trials, and they caution against the “therapeutic” use of placebo in long-standing CRPS.In this meta-analysis of placebo responses in randomized controlled trials in long-standing CRPS, published during 1966 to 2013, we found no evidence for placebo analgesia, except at very early time points. Results inform the design of future placebo analgesia research in long-standing CRPS.

Topics in medicine 50 years ago

Topics in medicine 50 years ago

Pregnancy and Antiphospholipid Syndrome.

Antiphospholipid syndrome (APS) is classified as the association of thrombotic events and/or obstetric morbidity in patients persistently positive for antiphospholipid antibodies (aPL). APS is also the most frequently acquired risk factor for a treatable cause of recurrent pregnancy loss and increases the risk of conditions associated with ischemic placental dysfunction, such as stillbirth, intrauterine death, preeclampsia, premature birth, and fetal growth restriction. The use of low-dose aspirin and heparin has improved the pregnancy outcome in obstetric APS and approximately 70% of pregnant women with APS will deliver a viable live infant. However, current management does not prevent all maternal, fetal, and neonatal complications of APS and the current treatment fails in 20 to 30% of APS pregnancies, raising the need to explore other treatments to improve obstetrical outcome. Two clinical studies of retrospective design have suggested that the immunomodulator hydroxychloroquine (HCQ) may play a role in the prevention of pregnancy complications in women with aPL and APS. The randomized controlled multicenter trial of hydroxychloroquine versus placebo during pregnancy in women with antiphospholipid antibodies (HYPATIA) of HCQ versus placebo will provide scientific evidence on the use of HCQ in pregnant women with aPL.

Safety of fondaparinux for prevention of postoperative venous thromboembolism in urological malignancy: A prospective randomized clinical trial.

To prospectively evaluate the safety of postoperative fondaparinux in comparison with low molecular weight heparin in patients undergoing uro-oncological surgery. The present study was a prospective, single-blind, non-inferiority randomized trial. A total of 359 patients undergoing surgery for urological malignancy were enrolled from January 2011 to December 2012. A total of 298 of these patients (fondaparinux group, 152; low molecular weight heparin group, 146) were evaluable for the intention-to-treat-analysis. Patients were randomly assigned to low-dose unfractionated heparin, 5000 units twice daily until postoperative day 1 plus either fondaparinux 2.5 mg once daily or low molecular weight heparin 2000 units twice daily until postoperative day 5. The primary end-point was postoperative bleeding as by independent review, and the study was powered to show the non-inferiority of fondaparinux versus low molecular weight heparin. The other adverse events were evaluated. D-dimer and soluble fibrin monomer complex levels were measured perioperatively. Bleeding occurred in 21 patients (12 in the fondaparinux group and 9 in low molecular weight heparin group, respectively). No significant differences were detected in the incidence of postoperative bleeding and the other adverse events between the two groups. The D-dimer was elevated on postoperative day 1 in one patient (16.6 μg/mL). In another patient, the soluble fibrin monomer complex was elevated (109 μg/mL). Fondaparinux is non-inferior to low molecular weight heparin with respect to risk of bleeding. The favorable safety profile of fondparinux supports its prophylactic use as an alternative to low molecular weight heparin after surgery for urological malignancy.

Venous thromboembolism prevention during asparaginase-based therapy for acute lymphoblastic leukemia.

Venous thromboembolism (vte) is a recognized complication in patients treated with asparaginase-containing chemotherapy regimens; the optimal preventive strategy is unclear. We assessed the safety and efficacy of prophylaxis using low-dose low molecular weight heparin in adult patients with acute lymphoblastic leukemia in complete remission treated with an asparaginase-based post-remission chemotherapy regimen. As part of the intensification phase of the Dana-Farber Cancer Institute 91-01 regimen, asparaginase was administered weekly to 41 consecutive patients for 21-30 weeks; these patients also received prophylaxis with enoxaparin 40 mg daily (60 mg for patients ≥80 kg). Outcomes were assessed against outcomes in a comparable cohort of 99 patients who received the same chemotherapy regimen without anticoagulation prophylaxis. The overall rate of symptomatic venous thrombosis was not significantly different in the prophylaxis and non-prophylaxis cohorts (18.92% and 21.74% respectively). Among patients receiving prophylaxis, vte occurred in higher proportion in those who weighed at least 80 kg (42.86% vs. 4.35%, p = 0.0070). No major bleeding complications occurred in the prophylaxis group (minor bleeding: 8.1%). Prophylaxis with low-dose enoxaparin during the intensification phase was safe, but was not associated with a lower overall proportion of vte.

Factors Associated With Continuous Low-Dose Heparin Infusion for Central Venous Catheter Patency in Critically Ill Children Worldwide.

To identify patient, hospital, and central venous catheter factors that may influence the use of low-dose heparin infusion for central venous catheter patency in critically ill children. Secondary analysis of an international multicenter observational study. Fifty-nine PICUs over four study dates in 2012, involving seven countries. Children less than 18 years old with a central venous catheter who were admitted to a participating unit and enrolled in the completed Prophylaxis against Thrombosis Practice study were included. All overflow patients were excluded. None. Of the 2,484 patients in the Prophylaxis against Thrombosis Practice study, 1,312 patients had a central venous catheter. Five hundred seven of those patients used low-dose heparin infusion. The frequency of low-dose heparin infusion was compared across various patient, hospital, and central venous catheter factors using chi-square, Mann-Whitney U, and Fisher exact tests. In the multivariate analysis, age was not a significant factor for low-dose heparin infusion use. Patients with pulmonary hypertension had decreased low-dose heparin infusion use, whereas those with active surgical or trauma diagnoses had increased low-dose heparin infusion use. All centrally inserted central venous catheters were more likely to use low-dose heparin infusion when compared with peripherally inserted central venous catheters. The Asia-Pacific region showed increased low-dose heparin infusion use, along with community hospitals and smaller ICUs (< 10 beds). Patient, central venous catheter, and hospital factors are associated with the use of low-dose heparin infusion in critically ill children. Further study is needed to evaluate the efficacy and persistence of low-dose heparin infusion use.

Pravastatin to prevent obstetrical complications in women with antiphospholipid syndrome.

Pregnant women with antiphospholipid syndrome (APS) are at a high risk of obstetrical complications. The current standard of care, including the use of low-dose aspirin and heparin, has not been shown to prevent preeclampsia or intrauterine growth restriction (IUGR). Due to the similarities in pathophysiology among preeclampsia, IUGR, and atherosclerotic cardiovascular disease, statins have been proposed for treating and/or preventing these obstetrical complications. In this issue of the JCI, Lefkou et al. report on a small, observational trial that showed a dramatic improvement in both maternal and fetal/neonatal outcomes in women with APS given pravastatin after the onset of preeclampsia and/or IUGR compared with women in the control group. These results, along with other recent clinical studies, support further evaluation of statins for prevention of preeclampsia in a large-scale randomized clinical trial.

The role of prophylactic use of low dose aspirin and calheparin in patients with unexplained recurrent abortion

Objective: To study the effect of prophylactic use of low dose aspirin and heparin on patients with recurrent unexplained pregnancy loss.Methods: Prospective case control study conducted on 180 pregnant women randomized into two equal groups. Group 1 received low-dose aspirin 75 mg and heparin 5000 IU subcutaneous every 12 h. Group 2 received no treatment.Results: There was a statistically significant difference between the two study groups regarding number of patients who completed their first trimester (66 versus 39) (p values 0.018). The outcome regarding completion of first trimester was not related to age, BMI or number of previous abortions in both the study groups. Complications of the use of aspirin calheparin occurred in 60% of the patients. The most common complication was bruising at injection site occurring in 60% of the patients followed by bleeding gums (14.4%), gastrointestinal troubles (12.2%), epistaxis (10%) and transient thrombocytopenia in only 2.22% of the patients (Table 4).Conclusion: The use of prophylactic dose of calheparin and aspirin is associated with increased chance of passing 1st trimester safely regardless the age, body mass index or number of abortion in women with unexplained recurrent spontaneous abortion.

The role of unfractionated heparin for the antiaggregatory effect of aspirin in patients undergoing carotid endarterectomy: Results of an observational clinical study.

The aims of the present study were to examine the influence of a low-dose unfractionated heparin regime on platelet aggregation and to additionally assess the prevalence of primary aspirin resistance in patients undergoing carotid endarterectomy. Therefore, 50 patients undergoing carotid endarterectomy were enrolled. A bolus of 3000 IU unfractionated heparin was administered 2 min before carotid cross-clamping additionally to standard antiaggregatory therapy. Haemostaseological point of care testing was performed twice, prior to surgery and 10 min after unfractionated heparin administration by the use of aggregometric and viscoelastic point of care testing. Following unfractionated heparin administration, the activated partial thromboplastin time increased significantly and clotting time in viscoelastic INTEM test was shown to be significantly prolonged. In contrast, the antiaggregatory effect of aspirin was not diminished in aggregometric ASPI test. A low-dose unfractionated heparin regime during carotid endarterectomy was therefore considered to be safe, without diminishing the antiplatelet effect of aspirin. Moreover, aggregometric point of care testing was identified to be a suitable tool for the identification of patients with primary aspirin resistance ( n = 3).

Low-dose versus high-dose heparin locks for hemodialysis catheters: a systematic review and meta-analysis.

Low-dose heparin lock has been suggested as an effective and safe catheter lock in hemodialysis. However, whether a low-dose lock is superior to a high-dose heparin lock in preventing catheter-related infections and maintaining catheter patency is inconclusive. A systematic review and meta-analysis was performed by searching in NGC (National Guideline Clearinghouse), Cochrane Library, Joanna Briggs Institute Library, MEDLINE, EMbase, RNAO (Registered Nurses' Association of Ontario), Nursing Consult, PubMed, OVID, China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure (CNKI), Chongqing VIP (CQVIP), Wanfang Data Knowledge Service Platform, and major nephrology journals. Patients receiving hemodialysis with central venous catheters. Randomized controlled trials (RCT), controlled clinical trials (CCT), and cohort studies comparing low-dose heparin lock with high-dose heparin lock in hemodialysis patients with central venous catheters. Intervention (exposure): Locking central venous catheters with low-dose heparin lock. Primary outcomes include bleeding-related complications and catheter-related infections. Secondary outcomes include catheter retention time, catheter thrombosis/occlusion incidence, and catheter dysfunction. Five RCTs and three CCTs were eventually identified for the meta-analysis, with 916 patients in total. Meta-analysis showed that, compared with the high-dose heparin group (≥ 5,000 U/mL), the low-dose (< 5,000 U/mL) heparin lock could significantly reduce the incidences of bleeding- related complications RR = 3.29, 95% CI (2.19, 4.94), p < 0.00001) and catheterrelated infections (RR = 1.66, 95% CI (1.01, 2.73), p = 0.04). However, no significant differences were observed in the catheter retention time MD = 9.32, 95% CI (-6.70, 25.35), p = 0.25), catheter thrombosis/occlusion incidence (RR = 0.68, 95% CI (0.28, 1.65), p = 0.39), or catheter dysfunction (RR = 1.07, 95% CI (0.75, 1.53), p = 0.71) between the high- and low-dose heparin groups. Low-dose heparin lock could decrease the incidences of catheter-related infections and bleeding-related complications without influencing the catheter retention time or the incidence of catheter thrombosis/occlusion or catheter dysfunction. Low-dose heparin lock solution should be recommended for the hemodialysis patients using central venous catheter in clinic.

Novel Treatments in Neuroprotection for Aneurysmal Subarachnoid Hemorrhage.

New neuroprotective treatments aimed at preventing or minimizing "delayed brain injury" are attractive areas of investigation and hold the potential to have substantial beneficial effects on aneurysmal subarachnoid hemorrhage (aSAH) survivors. The underlying mechanisms for this "delayed brain injury" are multi-factorial and not fully understood. The most ideal treatment strategies would have the potential for a pleotropic effect positively modulating multiple implicated pathophysiological mechanisms at once. My personal management (RFJ) of patients with aneurysmal subarachnoid hemorrhage closely follows those treatment recommendations contained in modern published guidelines. However, over the last 5years, I have also utilized a novel treatment strategy, originally developed at the University of Maryland, which consists of a 14-day continuous low-dose intravenous heparin infusion (LDIVH) beginning 12h after securing the ruptured aneurysm. In addition to its well-known anti-coagulant properties, unfractionated heparin has potent anti-inflammatory effects and through multiple mechanisms may favorably modulate the neurotoxic and neuroinflammatory processes prominent in aneurysmal subarachnoid hemorrhage. In my personal series of patients treated with LDIVH, I have found significant preservation of neurocognitive function as measured by the Montreal Cognitive Assessment (MoCA) compared to a control cohort of my patients treated without LDIVH (RFJ unpublished data presented at the 2015 AHA/ASA International Stroke Conference symposium on neuroinflammation in aSAH and in abstract format at the 2015 AANS/CNS Joint Cerebrovascular Section Annual Meeting). It is important for academic physicians involved in the management of these complex patients to continue to explore new treatment options that may be protective against the potentially devastating "delayed brain injury" following cerebral aneurysm rupture. Several of the treatment options included in this review show promise and could be carefully adopted as the level of evidence for each improves. Other proposed neuroprotective treatments like statins and magnesium sulfate were previously thought to be very promising and to varying degrees were adopted at numerous institutions based on somewhat limited human evidence. Recent clinical trials and meta-analysis have shown no benefit for these treatments, and I currently no longer utilize either treatment as prophylaxis in my practice.

Managing acute stroke in low-resource settings.

Managing acute stroke in low-resource settings.

Heparin for the prevention of intraventricular haemorrhage in preterm infants.

Preterm birth remains the major risk factor for the development of intraventricular haemorrhage, an injury that occurs in 25% of very low birth weight infants. Intraventricular haemorrhage is thought to be venous in origin and intrinsic thromboses in the germinal matrix are likely to play a triggering role. Heparin activates antithrombin and promotes the inactivation of thrombin and other target proteinases. The administration of anticoagulants such as heparin may offset the increased risk of developing intraventricular haemorrhage and may also reduce the risk of developing parenchymal venous infarct, a condition known to complicate intraventricular haemorrhage. To assess whether the prophylactic administration of heparin reduces the incidence of germinal matrix-intraventricular haemorrhage in very preterm neonates when compared to placebo, no treatment, or other anticoagulants. We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2015), MEDLINE (1996 to 22 November 2015), EMBASE (1980 to 22 November 2015) and CINAHL (1982 to 22 November 2015), applying no language restrictions. We searched the abstracts of the major congresses in the field (Perinatal Society of Australia and New Zealand and Pediatric Academic Societies) from 2000 to 2015. Randomised controlled trials, quasi-randomised controlled trials and cluster trials comparing the administration of early, i.e. within the first 24 hours of life, heparin in very preterm infants (gestational age < 32 weeks). For each of the included trials, two authors independently extracted data (e.g. number of participants, birth weight, gestational age, dose of heparin, mode of administration, and duration of therapy, etc.) and assessed the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow up). The primary outcomes considered in this review are intraventricular haemorrhage, severe intraventricular haemorrhage and neonatal mortality. Two randomised controlled trials enrolling a total of 155 infants met the inclusion criteria of this review. Both trials compared low-dose heparin to the same solution without heparin in very preterm newborns requiring umbilical catheterisation. No trials were identified that specifically studied the use of heparin in infants at risk of germinal matrix-intraventricular haemorrhage.We found no differences in the rates of intraventricular haemorrhage (typical RR 0.93, 95% CI 0.61 to 1.41; typical RD -0.03, 95% CI -0.17 to 0.12; 2 studies, 155 infants; I² = 57% for RR and I² = 65% for RD), severe intraventricular haemorrhage (typical RR 1.01, 95% CI 0.46 to 2.23; typical RD 0.00, 95% CI -0.11 to 0.11; 2 studies, 155 infants; I² = 0% for RR and I² = 0% for RD) and neonatal mortality (typical RR 0.69, 95% CI 0.28 to 1.67; typical RD -0.04, 95% CI -0.14 to 0.06; 2 studies, 155 infants; I² = 28% for RR and I² = 50% for RD). We judged the quality of the evidence supporting these findings as very low (rates of intraventricular haemorrhage) and low (severe intraventricular haemorrhage and neonatal mortality) mainly because of limitations in the study designs and the imprecision of estimates. We found very few data on other relevant outcomes, such as bronchopulmonary dysplasia, pulmonary haemorrhage and patent ductus arteriosus; and no study assessing long-term outcomes (e.g. neurodevelopmental disability). There is very limited data on the effect of prophylactic administration of heparin on the incidence and severity of IVH in very preterm neonates. Both the identified trials used heparin in the context of maintaining umbilical line patency and not specifically as an agent to prevent germinal matrix-intraventricular haemorrhage. Given the imprecision of our estimates, the results of this systematic review are consistent with either a benefit or a detrimental effect of heparin and do not provide a definitive answer to the review question. Limited evidence is available on other clinically relevant outcomes.

Are all heparins safe for on-pump heart surgery?

ABSTRACTBackground: Intravenous Panpharma heparin® was used in all on-pump cardiac surgery in our heart-surgery department for a short period. This brand of heparin replaced the previous Choay heparin® heparin supplied by the Sanofi-Aventis Laboratory. Unusual postoperative bleedings over this period prompted us to evaluate postoperative hemostasis by comparing these two heparins.Methods: We compared data from patients who had undergone on-pump cardiac surgery during Panpharma heparin® period (group P, 257 patients) to those how received Choay heparin® (group C, 194 patients).Results: Despite group P receiving a significantly lower dose of heparin (mean dose 21,000 IU/CEC) compared to group C (mean dose 22,000 IU/CEC) (p = 0.05), the number of surgical re-explorations needed to perfect postoperative hemostasis was significantly higher for group P (3.5% vs. 0) (p = 0.01). Heparin anti-Xa activity after surgery was higher in group P at postoperative h1 and h12 compared to group C, which explained reoperations for hemostasis.Conclusion: Despite standardization, variations remain regarding anticoagulant activity between different manufacturing processes and heparin preparations. Surgical teams need to be aware that the biological effects of different brands of heparin may not be as expected and could endanger a usually safe procedure, such as cardiac surgery.

95. Incorporation of AAV Serotype 2 Viral Protein 2 into Other AAV Serotype Capsids

It was previously documented that large ligands inserted after residue 138 in the adeno-associated virus serotype 2 (AAV2) viral protein 2 (VP2) is tolerant to produce nearly wild-type levels of recombinant AAV2 (rAAV2) vectors (J Virol. 78(12):6595-609, 2004). Furthermore, insertion of enhanced green fluorescent protein (EGFP) into VP2 resulted in a rAAV2 particle, whose trafficking could be temporally monitored using confocal microscopy. Here, we examined whether AAV2 VP2 (2VP2) could be incorporated into other AAV serotype capsids during viral production.A pcDNA3.1-based plasmid was generated to over-express only the 5’-EGFP-tagged 2VP2 (EGFP-2VP2), but not other viral proteins, such as AAV2 Reps, VP1, or VP3. Then, rAAV1~10 vectors were produced in HEK293 cells using PEI-mediated, quadruple-plasmid transfection. The four plasmids for each rAAV vector included a packaging plasmid that contains AAV2 rep genes and a corresponding cap gene, a helper plasmid that provides essential genes from adenovirus, an ITR-containing plasmid that carries a reporter gene encoding firefly luciferase (Fluc), and the pcDNA3.1-EGFP-2VP2 plasmid. The expression of corresponding VP2 in each serotype capsid was not blocked. Purified viral stocks were separated by SDS-12% acrylamide gel electrophoresis and analyzed by Western blot assays with the B1 antibody or EGFP antibody. The results indicated that the EGFP-2VP2 protein was successfully inserted into all tested rAAV vectors, except for rAAV5. Approximately one-tenth to one-half of the total VP2 was substituted by EGFP-2VP2, depending on the serotype. Next, we characterized the novel rAAV2 and rAAV3 particles that had EGFP-2VP2 insertions. Four vectors (WT-rAAV2, rAAV2-EGFP-2VP2, WT-rAAV3, rAAV3-EGFP-2VP2) carrying the fluc gene were used to transduce a human hepatocellular carcinoma cell line, Huh7, under identical conditions in vitro. There was no difference in the transgene expression between the WT and EGFP-2VP2-inserted vectors. Furthermore, when heparin was added in the cell culture, the transduction efficiency of both rAAV2 vectors was inhibited in a dose-dependent manner. On the other hand, the transduction efficiency of rAAV3-2VP2-EGFP vectors showed a similar pattern to that was previously reported for WT-rAAV3 vectors, in which low doses of heparin significantly enhanced rAAV3 transduction, but high doses inhibited it. The tropism of rAAV2-EGFP-2VP2 vectors was further characterized in vivo following tail-vein injection of Balb/c mice and showed no difference compared with the WT-rAAV2 vectors. Finally, the trafficking of both rAAV2-EGFP-2VP2 and rAAV3-EGFp-2VP2 was temporally monitored using confocal microscopy.In summary, we have demonstrated an easy method that can be used to insert large peptides into most AAV serotype particles. This system may provide significant information to study rAAV transduction.

Hidden Barriers to Delivery of Pharmacological Venous Thromboembolism Prophylaxis

Standardized electronic order sets for venous thromboembolism prophylaxis have increased the proportion of patients receiving venous thromboembolism prophylaxis. However, ordering venous thromboembolism prophylaxis does not ensure consistent administration. To explore causes of variability in the rate of administration of ordered doses of pharmacological venous thromboembolism prophylaxis among hospital units. Mixed methods study, including qualitative observation and quantitative nursing survey administration. Nurses included in observations were practicing on an inpatient unit, caring for patients with orders to receive venous thromboembolism prophylaxis consisting of low-dose unfractionated heparin or low-molecular weight heparin. Nurses on 12 inpatient units with disparate rates of administration were included in the survey. Qualitative observation data were collected until thematic saturation was achieved. Survey was conducted to identify beliefs and practices surrounding nursing administration of venous thromboembolism prophylaxis. During observations, some nurses presented pharmacological venous thromboembolism prophylaxis to their patients as an optional therapy. Nurses on low-performing units are more likely to believe that pharmacological venous thromboembolism prophylaxis is ordered for patients who do not require it. More often, they also acknowledge that nurses use their clinical decision-making skills to determine when to omit unnecessary doses of prescribed venous thromboembolism prophylaxis. Nurses on units with low administration rates often believe they have the skills to determine which patients require pharmacological venous thromboembolism prophylaxis. They are also more likely to believe that ordered doses are discretionary and offer the medication as optional to patients.