Haemolysis Rates Research Articles

Designing Analogs of SAAP-148 with Enhanced Antimicrobial and Anti-LPS Activities.

SAAP-148, a derivative of LL-37, exhibits a well-defined amphipathic structure and enhanced antimicrobial activity; however, it also displays significant cytotoxicity towards human cells. In this study, we employed Lys-scan to produce a series of amphiphilic SAAP-148 analogs derived from the SAAP-148 sequence to investigate the impact of the distribution of positively charged residues on the biological viability of the antimicrobial peptides (AMPs). The physical properties and biological activity of the designed peptides were subsequently compared. The substitution of lysine resulted in an increase in the overall charge of SAAP-148 and a decrease in its overall hydrophobicity and hyd. moment, except for SAAP-10 where an analogue substitution occurred at the 18th residue. The replacement of lysine led to a reduction in hemolytic activity compared to SAAP-148, with slightly higher haemolysis rates observed in SAAP-11 and SAAP-13. The cytotoxicity of peptides towards human normal lung epithelial cells (BEAS-2B) was closely linked to their haemolytic activity, indicating that substituting lysine may mitigate the cytotoxic effects of SAAP-148. Additionally, the arrangement of positively charged residues in the peptides significantly influenced its antimicrobial activity. Our findings suggest that the positioning of a positively charged residue has a significant impact on the biophysical properties of the peptide. Additionally, the substitution of lysine at different positions demonstrates an influence on the anti-lipopolysaccharide (anti-LPS) activity of SAAP-148. These discoveries provide valuable insights for the design and optimization of antimicrobial peptides, which will be advantageous for the future development of antimicrobial agents.

The impact of blood sampling technique, including the use of peripheral intravenous cannula, on haemolysis rates: A cohort study.

To explore the relationship between blood sampling techniques and haemolysis. Haemolysis rates of blood samples have been thought to be influenced by the method of collection. There is a lack of research evidence available to clearly show the comparative risk of haemolysis across different blood sampling methods, including venepuncture and use of peripheral intravenous cannulas. A prospective cohort study. Reporting followed the STROBE checklist. A trained observer was used to record blood sampling techniques over a 10-week period between April and June 2019. These records were then linked to pathology haemolysis results. Multivariable logistic regression was used to model patient and blood draw characteristics affecting haemolysis. Most of the blood samples were not haemolysed (n=324, 87.1%). Multivariable analysis showed haemolysis was associated with increased tourniquet duration and if the level of tube was less than half full. Univariable analysis showed haemolysis was associated with increased age of the patient, the difficulty of cannulation/ venepuncture and increased number of attempts. No difference was found in the haemolysis rate related to the qualification of the blood collector. There was no significant difference in haemolysis rates associated with sampling blood from a PIVC compared with venepuncture. Research should be undertaken to determine whether education on the factors influencing haemolysis is useful in decreasing haemolysis rates. There was no association with increased haemolysis rates when drawing blood via venepuncture compared with a peripheral intravenous cannula. Haemolysis of blood samples was associated with increased tourniquet duration, if level of the tube was less than half-filled, increased age of the patient and difficulty of blood draw. Awareness of the risk of haemolysis associated with specific blood sampling methods may assist clinicians to improve care.

Implementation evaluation of pre-hospital blood collection in regional Australia: a mixed methods study

BackgroundIn response to increasing emergency department presentations and wait times in Australia, multiple strategies and models of care have been implemented with varying results. One effective strategy has been the implementation of pre-hospital blood collection by paramedics when they insert an intravenous cannula. This research aims to determine the efficiency of and barriers to wider implementation of a pre-hospital blood collection trial in a regional context. In particular, to evaluate the impact of the pre-hospital blood collection on time to pathology results and error rates, and paramedic opinion. MethodsThis retrospective controlled cohort study was conducted over 12 months from August 2018. Emergency and pathology data were used to determine the haemolysis and error rates, as well as the time to result availability of pre-hospital blood collection samples compared to in hospital samples arrived by ambulance. To determine the facilitators and barriers to wider implementation a survey of 48 paramedics was conducted following completion of the 12-month trial. The survey was informed by the Theoretical Domains Framework, a behavior change theory associated with improved uptake when applied. FindingsOverall 237 samples were collected. There was a 65% (51min) reduction in time taken for samples to be received at pathology and a 38% (50min) improvement in time taken for results to return from pathology for patients arrived by ambulance. There were no labelling errors in the pre-hospital blood collection group or change in haemolysis rates. The majority (79%) of paramedics who completed the survey were optimistic about the protocol improving patient outcomes and 89% regarded the change in practice as acceptable. Three main themes emerged: 1. Training, environmental challenges and adequate equipment; 2. increased efficiency and improved patient care and 3. Prerequisites to implementing a new practice. Integration of Quantitative and Qualitative data resulted in 10 key influencers of behavior that need to be addressed in any future implementation. Conclusion and implications for practiceThe introduction of pre-hospital phlebotomy reduced the time to blood results availability by 38% and resulted in fewer labelling errors. Wider implementation is supported by paramedics, but more training is required.

Biocompatibility, cytotoxicity and antibacterial effects of meropenem-loaded mesoporous silica nanoparticles against carbapenem-resistant Enterobacteriaceae

Background The ever-increasing resistance to antimicrobial agents among bacteria associated with nosocomial infections indicate the necessity of new antimicrobial therapy. The nanoparticles are considered as new drug delivery systems to increase the efficiency and decrease the unfavourable effects of the antimicrobial agents. Methods Herein we report the preparation and characterization of mesoporous silica nanoparticles (MSNs) loaded with meropenem against carbapenem-resistant Enterobacteriaceae. The antimicrobial effect of meropenem-loaded MSNs was determined against Enterobacteriaceae using the minimum inhibitory (MIC) method. The biocompatibility of meropenem-loaded MSNs was studied by the impact on the haemolysis and sedimentation rates of human red blood cells (HRBCs). Cytotoxicity of the meropenem-loaded MSNs was studied by the MTT test (hBM-MSC cell viability). Results The meropenem-loaded MSNs have shown antibacterial activity on all isolates at different MIC values lower than MICs of meropenem. Free MSNs did not show any significant antibacterial effect. Meropenem-loaded MSNs have no significant effect on haemolysis and ESR of HRBCs. The viability of hBM-MSC cells treated with serial concentrations of meropenem-loaded MSNs was 92–100%. Conclusion Due to the desirable biocompatibility, low cytotoxicity and the improved antibacterial effect, MSNs can be considered as a promising drug delivery system for meropenem as a potential antimicrobial agent.

Quality of red blood cell and platelet concentrates after transportation by a pneumatic tube system

Background and objectivesPneumatic tube systems (PTSs) are used in some hospitals to transport patients’ specimens. We investigated the feasibility of applying PTS for blood products for transfusion in our hospital.Materials and methodsWe transported red blood cells (RBCs) and platelet concentrates (PCs) by the PTS and measured biomarkers such as red cell haemolysis and platelet dysfunction before and after one‐way transportation, in addition, after one‐way transportation for three consecutive times by PTS.ResultsUsing 25 RBCs, K, free Hb, Hb, LD, AST and pH were compared before and after transportation. There were no significant differences. Haemolysis rates ranging between 0·13% and 0·35% were acceptable under the guideline. Using 6 PCs, platelet concentration, aggregation and activation function were examined. There were no significant differences before and after transportation. Positive rates of CD62P ranging between 3·1% and 11·4% showed no remarkable changes after the transportation. After the third consecutive transportation, LD and AST were slightly increased. However, haemolysis rate changed from 0·16% to 0·21%, again stayed in guideline level. As for platelet products, platelet aggregation activities to collagen (approximately 80%) did not change significantly.ConclusionOur study demonstrated that PTS is feasible for transporting them since one‐ and three‐time transportation by PTS does not appear to influence the important quality of RBCs and PCs. In our hospital, we have applied PTS for the transportation of blood products without major troubles such as loss of products or transfusion‐related adverse events.

The impact of venepuncture training on the reduction of pre-analytical blood sample haemolysis rates: A systematic review.

Venepuncture involves the introduction of a needle into a vein to collect a representative blood sample for laboratory testing. In the pre-analytical phase, haemolysis (the rupturing of erythrocytes and release of their contents into the extracellular compartment) has safety, quality and cost implications. Training in correct venepuncture practice has the potential to reduce in vitro haemolysis rates, but the evidence for this notion has yet to be synthesised. Systematic review (PRISMA Checklist). Published studies on the effectiveness of venepuncture training on haemolysis rates were searched in relevant databases. The McMaster critical appraisal tool was used to assess methodological quality. The GRADE tool was used to evaluate the body of evidence in relation to the research questions. Implementation fidelity was also scrutinised in each study. Eight out of 437 retrieved studies met the inclusion criteria. None were randomised controlled trials (RCT). Between-study heterogeneity in design, intervention characteristics and the biochemical threshold for haemolysis precluded a meta-analysis. Post-training reductions in haemolysis rates of between 0.4%-19.8% were reported in four of the studies, which developed their intervention according to a clear evidence base and included mentoring in the intervention. Rises in haemolysis rates of between 1.3%-1.9% were reported in two studies, while the intervention effect was inconsistent within two other studies. There are no RCTS on the effectiveness of venepuncture training for reducing haemolysis rates, and findings from the existing uncontrolled studies are unclear. For a more robust evidence base, we recommend more RCTs with standardisation of haemolysis thresholds and training-related factors. While venepuncture training is an important factor influencing quality of blood sample in clinical practice, more robust evidence is needed to make specific recommendations about training content for reduction of haemolysis rates. Standardisation of haemolysis thresholds would also enable future meta-analyses.

Drawing blood from peripheral intravenous cannula compared with venepuncture: A systematic review and meta-analysis.

To synthesize the evidence evaluating if blood samples are similar when obtained from peripheral intravenous cannula compared with venepuncture. A systematic review and meta-analysis was undertaken. Searches were conducted in databases for English language studies between January 2000-December 2018. The search adhered to the Meta-analysis of Observational Studies in Epidemiology guidelines. The methodological quality of studies was assessed using Joanna Briggs critical appraisal instruments. The overall quality of the evidence was assessed using the GRADE. Sixteen studies were identified. Findings suggest haemolysis rates are higher in blood sampled from peripheral intravenous cannula. However, haemolysis rates may be lower if a peripheral intravenous cannula blood sampling protocol is followed. For equivalence of blood test results, even though some results were outside the laboratory, allowable error and were outside the Bland-Altman Level of Agreement, none of these values would have required clinical intervention. With regard to the contamination rates of blood cultures, the results were equivocal. Further research is required to inform the evidence for best practice recommendations, including, if a protocol for drawing blood from a peripheral cannula is of benefit for specific patient populations and in other settings. Venepuncture can provoke pain, anxiety and cause trauma to patients. Guidelines recommend blood samples from peripheral intravenous cannula be taken only on insertion. Anecdotal evidence suggests drawing blood from existing cannulas may be a common practice. Further research is required to resolve this issue.

Effects of simulated gastrointestinal digestion on the physicochemical properties, erythrocyte haemolysis inhibitory ability and chemical antioxidant activity of mulberry leaf protein and its hydrolysates

SummaryProteins and peptides must be degraded and modified in the gastrointestinal (GI) tract prior to absorption; this process changes their physicochemical and biological properties. Mulberry leaf protein (MP) and its hydrolysates (HMP) have favourable antioxidant activities. To investigate, in vitro and separately, the effects of GI digestion and intestinal digestion on the stability of MP and HMP, we monitored the changes in secondary structures, amino acids, molecular weights and antioxidant activities. We found that MP was more hydrolysed by pepsin than by pancreatin, unlike HMP. The final digests of MP and HMP were mainly composed of polypeptides (0.5–6.5 kDa) and oligopeptides (<0.5 kDa), respectively. The GI digestion influenced MP and HMP differently; GI digestion increased the antioxidant efficiency of MP and decreased that of HMP. For the intestinal digests, the antioxidant activities of MP and HMP also differed. The 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulphonic acid) diammonium salt (ABTS) radical quenching abilities of MP and HMP at 1 mg mL−1 were comparable to or exceeded that of L‐glutathione (GSH) and 6‐hydroxy‐2,5,7,8‐tetramethychroman‐2‐carboxylic acid (trolox). Meanwhile, the erythrocyte haemolysis rates of MP, HMP and their GI products at 0.05–1.0 mg mL−1 were significantly lower than that of the 2,2′‐azobis (isobutyramidine) dihydrochloride (AAPH) control. Both MP and HMP can be used as natural antioxidants and may promote digestive health.

Making sense of a haemolysis monitoring and reporting system: a nationwide longitudinal multimethod study of 68 Australian laboratory participant organisations.

The key incident monitoring and management systems (KIMMS) quality assurance program monitors incidents in the pre- and postanalytical phases of testing in medical laboratories. Haemolysed specimens have been found to be the most frequent preanalytical error and have major implications for patient care. The aims of this study were to assess the suitability of KIMMS for quality reporting of haemolysis and to devise a meaningful method for reporting and monitoring haemolysis. A structured survey of 68 Australian KIMMS laboratory participant organisations was undertaken. Quarterly haemolysis reports (2011-2014) were analysed. Among 110 million accessions reported, haemolysis rates varied according to the reporting methods that participants used for assigning accessions (16% of participants reported haemolysis by specimen and 83% reported by episode) and counting haemolysis rejections (61% by specimen, 35% by episode and 3% by test). More than half of the participants (56%) assigned accessions by episode and counted rejections by specimen. For this group, the average haemolysis rate per 100,000 episodes was 177 rejected specimens with the average rate varying from 100 to 233 over time. The majority of participants (91%) determined rejections using the haemolysis index. Two thirds of participants (66%) recorded the haemolysis manually in laboratory information systems. KIMMS maintains the largest longitudinal haemolysis database in the world. However, as a means of advancing improvements in the quality of the preanalytical laboratory process, there is a need to standardise reporting methods to enable robust comparison of haemolysis rejection rates across participant laboratories.

Haemocompatibility of iron oxide nanoparticles synthesized for theranostic applications: a high-sensitivity microfluidic tool

The poor heating efficiency of the most reported magnetic nanoparticles (MNPs), allied to the lack of comprehensive biocompatibility and haemodynamic studies, hampers the spread of multifunctional nanoparticles as the next generation of therapeutic bio-agents in medicine. The present work reports the synthesis and characterization, with special focus on biological/toxicological compatibility, of superparamagnetic nanoparticles with diameter around 18 nm, suitable for theranostic applications (i.e. simultaneous diagnosis and therapy of cancer). Envisioning more insights into the complex nanoparticle-red blood cells (RBCs) membrane interaction, the deformability of the human RBCs in contact with magnetic nanoparticles (MNPs) was assessed for the first time with a microfluidic extensional approach, and used as an indicator of haematological disorders in comparison with a conventional haematological test, i.e. the haemolysis analysis. Microfluidic results highlight the potential of this microfluidic tool over traditional haemolysis analysis, by detecting small increments in the rigidity of the blood cells, when traditional haemotoxicology analysis showed no significant alteration (haemolysis rates lower than 2 %). The detected rigidity has been predicted to be due to the wrapping of small MNPs by the bilayer membrane of the RBCs, which is directly related to MNPs size, shape and composition. The proposed microfluidic tool adds a new dimension into the field of nanomedicine, allowing to be applied as a high-sensitivity technique capable of bringing a better understanding of the biological impact of nanoparticles developed for clinical applications.

Analysis of haemolysis rates when comparing blood from intravenous catheter vs venepuncture in the emergency department setting

Aims: In vivo haemolysis is a source of interference across a range of different assays1,2 and occurs more frequently in the Emergency Department3 (ED) than other hospital departments. This study looked to further examine the known association4 between haemolysis and taking blood from intravenous catheters (IVC). Method: Via a minor change to the existing ED blood form, ED staff indicated whether the blood sample was drawn from an intravenous catheter or not. This data was collected along with haemolysis index (>35 mg/dL was taken as haemolysed). The significance of intergroup differences was tested using non-parametric methods. Further information regarding patient presenting complaint, diagnosis and initial observations was obtained retrospectively from clinical notes to examine for confounding factors. Results: Information on 2929 ED blood forms and associated haemolysis index was collected. Of these, blood collection method was indicated in 2081 (71%). 18.8% of samples drawn from IVC were haemolysed compared with 6.6% of venepuncture samples. Chi-square analysis with Yates correction yielded a χ2 of 59.273 equating to a p value of <0.01 Discussion: This study provides further evidence that blood drawn from cannulas is associated with increased rates of haemolysis and will test the hypothesis that patient illness severity is a confounding factor.

Evaluation of the BD vacutainer rapid serum tube on haemolysis markers in the emergency department

Aims Haemolysis is an important source of assay interference, especially in the Emergency Department (ED). A rapid-clotting serum tube, Becton-Dickinson (BD) Vacutainer Rapid Serum Tube (RST), was reported to reduce haemolysis rates compared to standard serum tubes. We evaluated the effect of RST on haemolysis markers compared with our current STAT testing tube, BD Vacutainer Plasma Separator Tube (PST). Methods Patients presenting to the ED over a 8-day period had an additional RST and BD Vacutainer non-gel heparin plasma tube collected. Blood was collected from 347 patients by trained nursing staff from an intravenous cannula using an adaptor device (Vacutainer Luer-Lok access device). All samples were then analysed for six haemolysis markers: haemolysis index, phosphate, magnesium, potassium, lactate dehydrogenase (LD), and aspartate aminotras-ferase (AST). Results We found 9% of samples were haemolysed (>0.5g/L free haemoglobin). Significant differences (p p 0.05) higher for phosphate and potassium and lower for LD. Discussion/conclusion RST tubes did not improve markers of haemolysis compared to plasma tubes.

Should DEHP be eliminated in blood bags?

Whole blood for transfusion was initially collected in glass bottles, but these are fragile, heavy to transport and prone to bacterial contamination. After the Second World War, Carl Walter experimented with plastics for collection and storage of blood, and found that di-ethylhexyl phthalate (DEHP) as plasticizer for polyvinyl chloride (PVC) had the most favourable properties [1, 2]. The breakage rate of frozen plasma in DEHP PVC is low, and the better storage properties of red cell concentrates in DEHP PVC are explained by leaching of plasticizer into the lipid bilayer of these cells, thereby improving membrane stability resulting in lower haemolysis rates [3]. However, ever since the 1970s, scientific and public concern has been raised on the toxicity of DEHP for transfused patients [4, 5]. DEHP and its metabolite mono ethylhexyl phthalate (MEHP) are associated with impairment of reproduction in animal models, resulting in testicular dysgenesis syndrome in (male) rodents, as reviewed in depth elsewhere [6], and particularly, neonates are susceptible to the risks of high exposure to DEHP. Due to the omnipresence of phthalates (not only DEHP), and some important differences in DEHP metabolism between animal models and humans [6], it is difficult to estimate the effect of DEHP toxicity in humans. A study of 234 young men showed no effect of MEHP in urine on their reproductive function [7], but others showed that DNA damage in sperm was associated with the MEHP concentration (after adjustment for other DEHP oxidative metabolites) [8]. In vitro human testis explants incubated with DEHP or MEHP showed that both significantly inhibited testosterone production [9], and a study of 881 men showed a 9% lower free androgen index between the lowest and the highest quartile of the proportion DEHP excreted as MEHP (P = 0.02) [10]. Also, an association was found between urinary MEHP concentrations and lower free T4 and lower total T3 thyroid hormones in adult men [11]. In addition to these effects on hormonal level in adult males, DEHP and its metabolites can have an effect on fetal development, with a shorter anogenital distance associated with higher metabolite concentrations in urine samples collected during pregnancy [12]. Others found no difference in T4 and testosterone levels, as well as no effect on phallic length in 13 male adolescents 14– 16 years of age that had underwent ECMO treatment in their neonatal period, as compared to ageand sexmatched controls [13]. Also, DEHP/MEHP exposure (as detected in cord blood) was significantly associated with a shorter pregnancy duration [14]. Despite these associations, they should be interpreted with care. DEHP is not the only phthalate that may cause these effects; studies that showed no association may not have been published; DEHP administered through the intestinal tract is converted to MEHP in a higher degree as by intravenously [15]; and because phthalates are everywhere in our environment, comparisons are less versus more, rather than absent versus present. DEHP-plasticized PVC has long been used as standard material for a wide range of applications, like packing foil (including food), building material, toys and plastic devices. DEHP is considered to be a ubiquitous environmental contaminant and is present in air, dust, water, soil and food. The latter is considered to be the main source of DEHP intake for the general population. The current daily intake is estimated to be between 2 and 5 lg/kg for adults and between 4 to 8 lg/kg for children [16, 17]. Various measures to reduce the use of DEHP-plasticized PVC have indeed resulted in a 2-times lower exposure to DEHP in the general population over the last two decades [18]. DEHP is applied in many medical devices, and depending on the procedure, patients can be exposed to high (peak) concentrations of DEHP, in the order of 1 mg per kg of bodyweight. One of the sources of DEHP exposure is the leaching from the blood bags into the content of the container, particularly into lipophilic solutions such as plasma [19], but also red cells. Therefore some patient groups, including pregnant or nursing women and children, are considered to be most at risk of possible harmful effects attributable to DEHP exposure by medical treatments. DEHP is broken down into various metabolites. First, it is hydrolysed to MEHP and then further oxidized to mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP),

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells

Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis. Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n=12), 13 and 22°C (test groups, n=12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy. Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24h (total 120h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42days of storage independent of temperature profiles. Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

Educational poster.

In an attempt to reduce haemolysation rates in an Australian ED, Corkill ( 2012 ) placed educational posters in staff toilet cubicles. This novel approach produced a statistically significant reduction in median haemolysis rates, from 4.92 per cent to 3.95 per cent (P=0.001), over a 12-month period.

Influence of fourth generation poly(propyleneimine) dendrimers on blood cells

Dendrimers provide many exciting opportunities for potential biomedical applications. However, owing to their positively charged surfaces, poly(propyleneimine) (PPI) dendrimers show toxic and haemolytic activities. One of the methods for masking the peripheral cationic groups is to modify them using carbohydrate residues. In this study, three types of the fourth generation PPI dendrimers-uncoated (PPI-g4), approximately 35% maltotriose (Mal-III)-coated (PPI-g4-OS), and approximately 90% Mal-III-coated (PPI-g4-DS) were investigated by assessing their effects on red blood cell (RBC) haemolysis in samples of pure RBCs, RBCs in the presence of human serum albumin (HSA) or human plasma, and RBCs in whole blood. Lymphocyte proliferation and platelet (PLT) aggregation were also studied in the presence of various concentrations of dendrimers. Although all dendrimers examined affected all the blood cells studied, the unmodified PPI-g4 had the most damaging effect. It caused high RBC haemolysis rates and PLT aggregation and greatly inhibited lymphocyte proliferation. These effects were caused by the cationic surface of this polymer. The modification of PPI-g4 with Mal-III reduced the effect of the dendrimer on all blood cells. The presence of HSA or plasma in the buffer containing the RBCs or RBC in whole blood significantly decreased the extent of dendrimer-driven haemolysis.

Testing the effects of educational toilet posters: A novel way of reducing haemolysis of blood samples within ED

Haemolysed blood samples are an unnecessary burden on Emergency Departments (ED) as they increase workloads and drive down efficiencies. Little empirical data exists that demonstrates the effectiveness of educational posters displayed in staff toilet cubicles. This study explored the impact educational toilet posters have on reducing haemolysis rates within the ED. A time series study of the clinical effect of educational toilet posters on reducing haemolysis rates throughout a 12 month period at the Gold Coast Hospital ED was undertaken. The GCH ED is a tertiary emergency service that has approximately 66,000 patient presentations per year. Data was collected prospectively. Analysis was undertaken to investigate the effects on total number of haemolysed samples and those clinically significant samples with a haemolytic index >3. Further investigation explored the specific effects on medical and nursing staff. Analysis undertaken using an independent t-test found that the pre-intervention data demonstrates a medium haemolysis rate of 4.92% (SD=1.04). This is a statistically significantly different (t=3.56, df=50, p=0.001) from the median post intervention data of 3.95% (SD=0.84). The difference of 0.97% (95%CI=0.42, 1.52) represents a 19.72% reduction in clinically significant haemolysed samples over the study period. This study reveals that the use of educational toilet posters had a positive impact on reducing the rates of haemolysed samples collected within the ED. This simple and cost effective educational initiative changed the behaviour of clinical staff. Further investigation is warranted to examine the impact of educational toilet posters on additional clinical scenarios.

Processing cord blood from premature infants into autologous red‐blood‐cell products for transfusion

The use of umbilical cord blood (UCB) for transfusion purposes has gained interest the past years. UCB transfusion could serve premature infants, who often need transfusions early in life. We investigated the suitability of different storage media. UCB was collected after 25 0/7--35 6/7 gestational weeks and centrifuged to concentrate red cells subsequently stored in saline-adenine-glucose-mannitol (SAGM), or in additive solution-3 (AS-3), or stored as whole blood in citrate-phosphate-dextrose-adenine-1. Quality parameters were measured at 7 day intervals during 35 days and compared to the standard RBC product. White-blood-cell- and platelet counts were higher in the UCB products. In the fractionated units, haemolysis remained below 1·0% in 64% after 14 days, and in 30% after 21 days. Storage in SAGM or AS-3 showed similar quality. Whole blood UCB showed better pH and haemolysis rates after 21 days. UCB can be processed into autologous products for premature infants. Shelf-life is limited to 14-21 days and compares unfavourably to stored whole blood. Considering the early transfusion needs in these infants, a short shelf-life would not be a practical objection.

Phlebotomy site haemolysis rates vary inversely with workload

Phlebotomy site haemolysis rates vary inversely with workload

Interaction of double-chained cationic surfactants, dimethyldialkylammoniums, with erythrocyte membranes: stabilization of the cationic vesicles by phosphatidylcholines with unsaturated fatty acyl chains.

We studied the interaction of double-chained cationic surfactants, dimethyldialkylammoniums, (CH3)2N+(CnH2n+1)2, with the lipid bilayer of guinea-pig erythrocytes by observing the haemolysis, aggregation and shape change in the erythrocytes. In the presence of sonicated dispersions of the five dimethyldialkylammoniums tested (n = 10, 12, 14, 16 and 18), haemolysis was induced dose dependently, and at 0.1 mM or higher concentrations, haemolysis was induced more rapidly by dimethyldialkylammoniums with shorter alkyl chains. The cationic surfactants with longer alkyl chains, such as dimethyldipalmitylammonium, induced aggregation of the erythrocytes before haemolysis fully progressed. The vesicles of these long-chain dimethyldialkylammoniums in the presence of phosphatidylcholines with unsaturated fatty acyl chains markedly reduced the haemolysis rates. Furthermore, in the presence of phosphatidylcholines with unsaturated acyl chains the formation of tightly aggregated structures of several erythrocytes was observed. These findings, and analysis by spin label 5-doxylstearic acid, indicate that phosphatidylcholines enriched with unsaturated acyl chains stabilize the cationic vesicles of long-chain dimethyldialkylammoniums and the interaction with the lipid bilayer of erythrocyte membranes as cationic vesicles became prominent.