Anti-Fouling Surfaces for Extracorporeal Membrane Oxygenation by Surface Grafting of Hydrophilic Sulfoxide Polymers.

Non-thrombogenic surfaces for extracorporeal membrane oxygenation (ECMO) devices are important to increase their duration of usage and to enable long-term life support. However, the contact of blood with the hydrophobic synthetic ECMO membrane materials such as poly(4-methyl-1-pentene) (PMP) can activate the coagulation cascade, causing thrombosis and a series of consequent complications during ECMO operation. Targeting this problem, we proposed to graft highly hydrophilic sulfoxide polymer brushes onto the PMP surfaces via gamma ray irradiation-initiated polymerization to improve the hemocompatibility of the membrane. Through this chemical modification, the surface of the PMP film is altered from hydrophobic to hydrophilic. The extent of plasma protein adsorption and platelet adhesion, the prerequisite mediators of the coagulation cascade and thrombus formation, are drastically reduced compared with those of the unmodified PMP film. Therefore, the method provides a facile approach to modify PMP materials with excellent antifouling properties and improved hemocompatibility demanded by the applications in ECMO and other blood-contacting medical devices.

Muscle Engagement Monitoring Using Self-Adhesive Elastic Nanocomposite Fabrics.

Insight into, and measurements of, muscle contraction during movement may help improve the assessment of muscle function, quantification of athletic performance, and understanding of muscle behavior, prior to and during rehabilitation following neuromusculoskeletal injury. A self-adhesive, elastic fabric, nanocomposite, skin-strain sensor was developed and validated for human movement monitoring. We hypothesized that skin-strain measurements from these wearables would reveal different degrees of muscle engagement during functional movements. To test this hypothesis, the strain sensing properties of the elastic fabric sensors, especially their linearity, stability, repeatability, and sensitivity, were first verified using load frame tests. Human subject tests conducted in parallel with optical motion capture confirmed that they can reliably measure tensile and compressive skin-strains across the calf and tibialis anterior. Then, a pilot study was conducted to assess the correlation of skin-strain measurements with surface electromyography (sEMG) signals. Subjects did biceps curls with different weights, and the responses of the elastic fabric sensors worn over the biceps brachii and flexor carpi radialis (i.e., forearm) were well-correlated with sEMG muscle engagement measures. These nanocomposite fabric sensors were validated for monitoring muscle engagement during functional activities and did not suffer from the motion artifacts typically observed when using sEMGs in free-living community settings.

Dressings and securements for the prevention of peripheral intravenous catheter failure in adults (SAVE): a pragmatic, randomised controlled, superiority trial.

BACKGROUND: Two billion peripheral intravenous catheters (PIVCs) are used globally each year, but optimal dressing and securement methods are not well established. We aimed to compare the efficacy and costs of three alternative approaches to standard non-bordered polyurethane dressings. METHODS: We did a pragmatic, randomised controlled, parallel-group superiority trial at two hospitals in Queensland, Australia. Eligible patients were aged 18 years or older and required PIVC insertion for clinical treatment, which was expected to be required for longer than 24 h. Patients were randomly assigned (1:1:1:1) via a centralised web-based randomisation service using random block sizes, stratified by hospital, to receive tissue adhesive with polyurethane dressing, bordered polyurethane dressing, a securement device with polyurethane dressing, or polyurethane dressing (control). Randomisation was concealed before allocation. Patients, clinicians, and research staff were not masked because of the nature of the intervention, but infections were adjudicated by a physician who was masked to treatment allocation. The primary outcome was all-cause PIVC failure (as a composite of complete dislodgement, occlusion, phlebitis, and infection [primary bloodstream infection or local infection]). Analysis was by modified intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12611000769987. FINDINGS: Between March 18, 2013, and Sept 9, 2014, we randomly assigned 1807 patients to receive tissue adhesive with polyurethane (n=446), bordered polyurethane (n=454), securement device with polyurethane (n=453), or polyurethane (n=454); 1697 patients comprised the modified intention-to-treat population. 163 (38%) of 427 patients in the tissue adhesive with polyurethane group (absolute risk difference -4·5% [95% CI -11·1 to 2·1%], p=0·19), 169 (40%) of 423 of patients in the bordered polyurethane group (-2·7% [-9·3 to 3·9%] p=0·44), 176 (41%) of 425 patients in the securement device with poplyurethane group (-1·2% [-7·9% to 5·4%], p=0·73), and 180 (43%) of 422 patients in the polyurethane group had PIVC failure. 17 patients in the tissue adhesive with polyurethane group, two patients in the bordered polyurethane group, eight patients in the securement device with polyurethane group, and seven patients in the polyurethane group had skin adverse events. Total costs of the trial interventions did not differ significantly between groups. INTERPRETATION: Current dressing and securement methods are commonly associated with PIVC failure and poor durability, with simultaneous use of multiple products commonly required. Cost is currently the main factor that determines product choice. Innovations to achieve effective, durable dressings and securements, and randomised controlled trials assessing their effectiveness are urgently needed. FUNDING: Australian National Health and Medical Research Council.

Nano- and micro-materials in the treatment of internal bleeding and uncontrolled hemorrhage.

Internal bleeding is defined as the loss of blood that occurs inside of a body cavity. After a traumatic injury, hemorrhage accounts for over 35% of pre-hospital deaths and 40% of deaths within the first 24 hours. Coagulopathy, a disorder in which the blood is not able to properly form clots, typically develops after traumatic injury and results in a higher rate of mortality. The current methods to treat internal bleeding and coagulopathy are inadequate due to the requirement of extensive medical equipment that is typically not available at the site of injury. To discover a potential route for future research, several current and novel treatment methods have been reviewed and analyzed. The aim of investigating different potential treatment options is to expand available knowledge, while also call attention to the importance of research in the field of treatment for internal bleeding and hemorrhage due to trauma.

Skin Glue Reduces the Failure Rate of Emergency Department-Inserted Peripheral Intravenous Catheters: A Randomized Controlled Trial.

STUDY OBJECTIVE: Peripheral intravenous catheters are the most common invasive device in health care yet have very high failure rates. We investigate whether the failure rate could be reduced by the addition of skin glue to standard peripheral intravenous catheter care. METHODS: We conducted a single-site, 2-arm, nonblinded, randomized, controlled trial of 380 peripheral intravenous catheters inserted into 360 adult patients. The standard care group received standard securement. The skin glue group received standard securement plus cyanoacrylate skin glue applied to the skin insertion site. The primary outcome was peripheral intravenous catheter failure at 48 hours, regardless of cause. Secondary outcomes were the individual modes of peripheral intravenous catheter failure: infection, phlebitis, occlusion, or dislodgement. RESULTS: Peripheral intravenous catheter failure was 10% lower (95% confidence interval -18% to -2%; P=.02) with skin glue (17%) than standard care (27%), and dislodgement was 7% lower (95% confidence interval -13% to 0%; P=.04). Phlebitis and occlusion were less with skin glue but were not statistically significant. There were no infections. CONCLUSION: This study supports the use of skin glue in addition to standard care to reduce peripheral intravenous catheter failure rates for adult emergency department patients admitted to the hospital.

Novel technologies can provide effective dressing and securement for peripheral arterial catheters: A pilot randomised controlled trial in the operating theatre and the intensive care unit.

BACKGROUND: Peripheral arterial catheters are widely used in the care of intensive care patients for continuous blood pressure monitoring and blood sampling, yet failure - from dislodgement, accidental removal, and complications of phlebitis, pain, occlusion and infection - is common. While appropriate methods of dressing and securement are required to reduce these complications that cause failure, few studies have been conducted in this area. OBJECTIVES: To determine initial effectiveness of one dressing and two securement methods versus usual care, in minimising failure in peripheral arterial catheters. Feasibility objectives were considered successful if 90/120 patients (75%) received the study intervention and protocol correctly, and had ease and satisfaction scores for the study dressing and securement devices of ≥ 7 on Numerical Rating Scale scores 1-10. METHODS: In this single-site, four-arm, parallel, pilot randomised controlled trial, patients with arterial catheters, inserted in the operating theatre and admitted to the intensive care unit postoperatively, were randomly assigned to either one of the three treatment groups (bordered polyurethane dressing (n=30); a sutureless securement device (n=31); tissue adhesive (n=32)), or a control group (usual practice polyurethane dressing (not bordered) (n=30)). RESULTS: One hundred and twenty-three patients completed the trial. The primary outcome of catheter failure was 2/32 (6.3%) for tissue adhesive, 4/30 (13.3%) for bordered polyurethane, 5/31 (16.1%) for the sutureless securement device, and 6/30 (20%) for the control usual care polyurethane. Feasibility criteria were fulfilled. Cost analysis suggested that tissue adhesive was the most cost effective. CONCLUSIONS: The pilot trial showed that the novel technologies were at least as effective as the present method of a polyurethane dressing for dressing and securement of arterial catheters, and may be cost effective. The trial also provided evidence that a larger, multicentre trial would be feasible.

Comparative analysis of novel esophageal pressure monitoring catheters versus commercially available alternatives in a biomechanical model of the thoracic cavity.

Transpulmonary pressure can be estimated using esophageal balloon (EB) catheters, which come in a variety of manufacturing configurations. We assessed the performance of novel polyurethane EB designs, Aspisafe NG and NG+, against existing alternatives. We created a biomechanical model of the chest cavity using a plastic chamber and an ex-vivo porcine esophagus. The chamber was pressurized (- 20 and + 20 cmH2O) to simulate pleural pressures. We conducted tests with various EB inflation volumes and measured transesophageal pressure (TEP). TEP measurement was defined as accurate when the difference between pressure within the EB and chamber was 0 ± 1 cmH2O. We computed the minimal (Vaccuracy-min) and maximal (Vaccuracy-max) EB inflation volumes of accuracy. Inflation volumes were further validated using a surrogate method derived by the clinically validated positive pressure occlusion test (PPOT). When the esophageal balloons were filled with inflation volumes within the range provided by the manufacturers, the accuracy of TEP measurements was marginal. Our tests found median Vaccuracy-min across EB of 0.00-0.50 mL (p = 0.130), whereas Vaccuracy-max ranged 0.50-2.25 mL (p = 0.002). Post PPOT validation, median TEP was - 0.4 cmH2O (- 1.5 to 0.3) (p < 0.001 among catheters). The Aspisafe NG and NG+ were accurate in 81.7% and 77.8% of the measurements, respectively. We characterized two new EBs, which demonstrated good benchtop accuracy in TEP measurements. However, accuracy was notably influenced by the precise selection of EB inflation volumes.

Consistency and applicability of return to function guidelines in tactical-athletes with exertional heat illness. A systematic review.

OBJECTIVE: To assess the consistency of return to sport and occupation recommendations following EHI provided in published clinical practice guidelines, consensus statements, position statements, and practice alerts. The agreement between medical policies governing the return to duty following EHI between the branches of the United States Armed Forces and published recommendations was assessed. METHODS: Ovid MEDLINE, Web of Science, and CINAHL databases were searched for clinical practice guidelines and position statements published at any time that guided return to activity in individuals with EHI. Methodological quality was assessed, and the specific recommendations for clinical management were extracted. Consistency of recommendations was evaluated. Agreement between published guidelines and the policies governing return to activity in military tactical athletes with heat injury were also evaluated. RESULTS: Guidelines developed by two civilian sports medicine societies in the United States detailing recommendations for return to function following EHI were identified. There was consistency between guidelines regarding recommendations that addressed abstinence from activity; medical follow-up; graded resumption of activity; and return to function. Pertaining military policy, contemporary regulations published in recent years reflected the recommendations provided in the professional guidelines. The greatest incongruence was noted in older military policies. CONCLUSIONS: This systematic review highlights the need for consistent recommendations across all branches of the military and medical specialties pertaining to returning servicemembers to duty after EHI .

Diamond-like carbon films prepared by a low temperature periodic process for application in ventricular assist devices.

Due to the poor tribological properties of titanium (Ti) and its alloy Ti6Al4V (commonly used for ventricular assist devices manufacturing), diamond-like carbon (DLC) films with excellent anti-wear properties are pursued to improve the wear resistance of Ti and its alloys. Considering the effect of temperature on magnets inside pump impellers and workpiece deformation, DLC films are preferred to be prepared under low temperature. In this study, DLC films were prepared on Ti6Al4V alloys by periodic and continuous processes, and the corresponding maximum deposition temperature was 85 and 154°C, respectively. The periodic DLC films exhibited the feature of columnar structure, and the surface hillocks were less uniform than that of continuous DLC films. The periodic DLC films possessed more sp3 -bonded structures, and the accessorial sp3 -bonding mainly existed in the form of CH. Compared to continuous DLC films, the periodic DLC films had lower residual stress and better adhesion with Ti6Al4V substrates. Both DLC films could effectively reduce the friction coefficient and wear rate of Ti6Al4V alloys both in air and fetal bovine serum (FBS), and the periodic DLC films exhibited superior anti-wear properties to that of continuous DLC films in FBS. Haemocompatibility evaluation revealed that both DLC films presented similar levels of more human platelet adhesion and activation as compared with that of bare Ti6Al4V. However, both DLC films significantly prolonged plasma clotting time in comparison to bare Ti6Al4V. This study demonstrates the potential of low-temperature DLC films as wear-resistant surface modification for VADs.

Investigation of heparin-loaded poly(ethylene glycol)-based hydrogels as anti-thrombogenic surface coatings for extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO), a critical life-sustaining tool, faces significant challenges for the maintenance of normal haemostasis due to the large volume of circulating blood continuously in contact with artificial surfaces, hyperoxia and excessive shear stresses of the extracorporeal circuit. From a biomaterials perspective, it has been hypothesised that drug eluting coatings composed of haemocompatible hydrogels loaded with an anticoagulant drug could potentially enhance the haemocompatibility of the circuit. Poly(ethylene glycol) (PEG) has been well established as a biocompatible and anti-fouling material with wide biomedical application. Unfractionated heparin is the most commonly used anticoagulant for ECMO. In the present study, the feasibility of using heparin-loaded PEG-based hydrogels as anti-thrombogenic surface coatings for ECMO was investigated. The hydrogels were synthesised by photopolymerisation using poly(ethylene glycol) diacrylate (PEGDA) as the crosslinking monomer and poly(ethylene glycol) methacrylate (PEGMA) as the hydrophilic monomer, with heparin loaded into the pre-gel solution. Factors which could affect the release of heparin were investigated, including the ratio of PEGDA/PEGMA, water content, loading level of heparin and the flow of fluid past the hydrogel. Our results showed that increased crosslinker content and decreased water content led to slower heparin release. The hydrogels with water contents of 60 wt% and 70 wt% could achieve a sustained heparin release by adjusting the ratio of PEGDA/PEGMA. The anticoagulation efficacy of the released heparin was evaluated by measuring the activated clotting time of whole blood. The hydrogels with desirable heparin release profiles were prepared onto poly(4-methyl-1-pentene) (PMP) films with the same chemical composition as the PMP ECMO membranes. The coatings showed sustained heparin release with a cumulative release of 70-80% after 7 days. Haemocompatibility tests demonstrated that PEG hydrogel coatings significantly reduced platelet adhesion and prolonged plasma recalcification time. These results suggest that heparin-loaded PEG hydrogels are potential anti-thrombogenic coatings for ECMO.

In vivo evaluation of skin integration with ventricular assist device drivelines.

BACKGROUND: Ventricular assist device (VAD) driveline exit site infection is a common complication. 3D scaffolds manufactured with highly homogeneous pores via melt electro-writing (MEW) may generate an improved skin-driveline interface which permits cellular in-growth and creates a barrier to prevent bacterial migration along the driveline tissue tunnel. This study investigated skin integration on segments of Heartmate 3 driveline: smooth polyurethane, velour, and on a custom MEW scaffold in a small animal model. METHODS: Drivelines with surfaces consisting of smooth polyurethane, velour bonded to smooth polyurethane, and smooth polyurethane with a MEW scaffold sleeve were implanted percutaneously in the dorsum of 42 rats. Each rat was implanted with 2 pieces of driveline of 2 cm in length. Skin integration was assessed after 7 and 14 days. RESULTS: Macroscopically, velour and MEW scaffold surfaces were anchored at the driveline-skin interface while smooth polyurethane samples were not attached. The histology analyses showed epidermal migration throughout the thickness of the velour and MEW scaffold groups. Evident tissue growth around single MEW scaffold fibers resulted in full coverage of the pores, while areas of compacted fibers were apparent in the velour group. Tissue ingrowth was significantly higher in the MEW group compared to the velour group after 7 (p < 0.0001) and 14 days (p < 0.0001). Marsupialization was observed in the smooth polyurethane samples. Mechanical pull-out forces were similar between velour and MEW scaffold groups at 7 and 14 days (p > 0.05). CONCLUSIONS: Velour and MEW scaffolds promoted epidermal integration while smooth polyurethane drivelines did not. Fine control of MEW scaffold structure production resulted in full cellular coverage and may reduce driveline infection.

The potential prognostic utility of salivary galectin-3 concentrations in heart failure.

BACKGROUND: Patients with HF are at a higher risk of rehospitalisation and, as such, significant costs to our healthcare system. A non-invasive method to collect body fluids and measure Gal-3 could improve the current management of HF. In this study, we investigated the potential prognostic utility of salivary Galectin-3 (Gal-3) in patients with heart failure (HF). METHODS: We collected saliva samples from patients with HF (n = 105) either at hospital discharge or during routine clinical visits. Gal-3 concentrations in saliva samples were measured by ELISA. The Kaplan-Meier survival curve analysis and Cox proportional regression model were used to determine the potential prognostic utility of salivary Gal-3 concentrations. RESULTS: The primary end point was either cardiovascular death or hospitalisation. Salivary Gal-3 concentrations were significantly higher (p < 0.05) in patients with HF who subsequently experienced the primary endpoint compared to those who did not. HF patients with salivary Gal-3 concentrations > 172.58 ng/mL had a significantly (p < 0.05) higher cumulative risk of the primary endpoint compared to those with lower salivary Gal-3 concentrations. In patients with HF, salivary Gal-3 concentration was a predictor of the primary endpoint even after adjusting for other covariates. CONCLUSIONS: In our pilot study, HF patients with salivary Gal-3 concentrations of > 172.58 ng/mL demonstrated a higher cumulative risk of the primary outcome compared to those with lower Gal-3 levels, even after adjusting for other variables. Confirming our findings in a larger multi-centre clinical trial in the future would enable salivary Gal-3 measurements to form part of routine management for patients with HF.

Improving skin integration around long-term percutaneous devices using fibrous scaffolds in a reconstructed human skin equivalent model.

The interface between synthetic percutaneous devices and skin is a common area for bacterial infection, which may ultimately result in failure of the device. Better integration of percutaneous devices with skin may help reduce infection rates due to the creation of a dermal seal. However, the mismatch in material and chemical properties of devices and skin presents a challenge for closing the dermal gap at the skin-device interface. Here, we have used a tissue engineering approach to tissue integration by creating a highly fibrous poly(ε-caprolactone) scaffold using melt electrowriting and seeding this with dermal fibroblasts, followed by maturation and insertion into a full-thickness defect made in an ex vivo skin model. The integration of seeded scaffolds was compared with controls including a non-seeded scaffold and a polymer tube with a smooth surface. Dermal fibroblast inclusion in the scaffold and epidermal upgrowth versus downgrowth/marsupialization around the device were used as measures of integration. Based on these measures, almost all pre-seeded scaffolds performed better than both the non-seeded scaffolds and smooth tubes. The hypothesis is that the fibroblasts act as a barrier to epithelial downward migration, and provide healthy tissue for nascent epidermal development.

Securement methods for peripheral venous catheters to prevent failure: a randomised controlled pilot trial.

PURPOSE: To assess the effectiveness of four securement methods to prevent peripheral intravenous catheter (PIVC) failure. METHODS: A single-centre, four-arm, randomised, controlled, non-blinded, superiority pilot trial was conducted in a tertiary referral hospital in Queensland (Australia), between November 2012 and January 2013. Adult patients, with a PIVC expected to remain in situ for ≥24 hours and admitted to general medical or surgical wards, were randomly allocated to standard polyurethane dressing (control, SPU), tissue adhesive (TA) with an SPU, bordered polyurethane dressing (BPU) or sutureless securement device (SSD) with an SPU, experimental groups. The primary endpoint was PIVC failure, defined as premature device removal before the end of therapy because of pain, blockage, leaking, accidental removal and local or catheter-related bloodstream infection. RESULTS: PIVCs were used for an average of 2.6 days across all study groups (n = 85). Catheter failure was lowest in the TA group (3/21, 14%) and highest in the control group (8/21, 38%), with BPU and SSD failure at 5/20 (25%) and 5/23 (22%), respectively. The adjusted hazard ratio of catheter failure was lowest in the TA group (0.50, 95% CI: 0.13-1.98), and then the BPU (0.52, 95% CI: 0.15-1.78) and SSD (0.61, 95% CI: 0.20-1.91) groups. No patient was suspected of a local or catheter-related bloodstream infection. CONCLUSIONS: Current SPU dressings alone do not prevent many cases of PIVC failure. TA appears promising as an innovative solution, but may not be suitable for all patients. A larger Australian National Health and Medical Research Council (NHMRC)-funded trial has commenced.

Securing All intraVenous devices Effectively in hospitalised patients--the SAVE trial: study protocol for a multicentre randomised controlled trial.

INTRODUCTION: Over 70% of all hospital admissions have a peripheral intravenous device (PIV) inserted; however, the failure rate of PIVs is unacceptably high, with up to 69% of these devices failing before treatment is complete. Failure can be due to dislodgement, phlebitis, occlusion/infiltration and/or infection. This results in interrupted medical therapy; painful phlebitis and reinsertions; increased hospital length of stay, morbidity and mortality from infections; and wasted medical/nursing time. Appropriate PIV dressing and securement may prevent many cases of PIV failure, but little comparative data exist regarding the efficacy of various PIV dressing and securement methods. This trial will investigate the clinical and cost-effectiveness of 4 methods of PIV dressing and securement in preventing PIV failure. METHODS AND ANALYSIS: A multicentre, parallel group, superiority randomised controlled trial with 4 arms, 3 experimental groups (tissue adhesive, bordered polyurethane dressing, sutureless securement device) and 1 control (standard polyurethane dressing) is planned. There will be a 3-year recruitment of 1708 adult patients, with allocation concealment until randomisation by a centralised web-based service. The primary outcome is PIV failure which includes any of: dislodgement, occlusion/infiltration, phlebitis and infection. Secondary outcomes include: types of PIV failure, PIV dwell time, costs, device colonisation, skin colonisation, patient and staff satisfaction. Relative incidence rates of device failure per 100 devices and per 1000 device days with 95% CIs will summarise the impact of each dressing, and test differences between groups. Kaplan-Meier survival curves (with log-rank Mantel-Cox test) will compare device failure over time. p Values of <0.05 will be considered significant. Secondary end points will be compared between groups using parametric or non-parametric techniques appropriate to level of measurement. ETHICS AND DISSEMINATION: Ethical approval has been received from Queensland Health (HREC/11/QRCH/152) and Griffith University (NRS/46/11/HREC). Results will be published according to the CONSORT statement and presented at relevant conferences. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trial Registry (ACTRN); 12611000769987.

Trephination for acute pain management.

Surgical trephination can and does provide immediate relief of pain, surgical drainage of the infection and related fluids, and in most cases does not require supplementary administration of antibiotics and only minimal amounts of analgesics. This paper outlines the diagnosis and technique of surgical trephination.

Autologous stem cells (adipose) and fibrin glue used to treat widespread traumatic calvarial defects: case report.

This is a report of a 7-year-old girl suffering from widespread calvarial defects after severe head injury with multifragment calvarial fractures, decompressive craniectomy for refractory intracranial hypertension and replantation of cryopreserved skull fragments. Chronic infection resulted in an unstable skull with marked bony defects. Two years after the initial injury the calvarial defects were repaired. Due to the limited amount of autologous cancellous bone available from the iliac crest, autologous adipose derived stem cells were processed simultaneously and applied to the calvarial defects in a single operative procedure. The stem cells were kept in place using autologous fibrin glue. Mechanical fixation was achieved by two large, resorbable macroporous sheets acting as a soft tissue barrier at the same time. The postoperative course was uneventful and CT-scans showed new bone formation and near complete calvarial continuity three months after the reconstruction.

Cytotoxicity of topical antimicrobial agents used in burn wounds in Australasia.

BACKGROUND: Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical antimicrobial agents has helped improve the survival of these patients. Silvazine (Sigma Pharmaceuticals, Melbourne, Australia) (1% silver sulphadiazine and 0.2% chlorhexidine digluconate) is used exclusively in Australasia, and there is no published study on its cytotoxicity. This study compared the relative cytotoxicity of Silvazine with 1% silver sulphadiazine (Flamazine (Smith & Nephew Healthcare, Hull, UK)) and a silver-based dressing (Acticoat (Smith & Nephew Healthcare, Hull, UK)). METHODS: Dressings were applied to the centre of culture plates that were then seeded with keratinocytes at an estimated 25% confluence. The plates were incubated for 72 h and culture medium and dressings then removed. Toluidine blue was added to stain the remaining keratinocytes. Following removal of the dye, the plates were photographed under standard conditions and these digital images were analysed using image analysis software. Data was analysed using Student's t-test. RESULTS: In the present study, Silvazine is the most cytotoxic agent. Seventy-two hour exposure to Silvazine in the present study results in almost no keratinocyte survival at all and a highly statistically significant reduction in cell survival relative to control, Acticoat and Flamazine (P<0.001, P<0.01, P<0.01, respectively). Flamazine is associated with a statistically significant reduction in cell numbers relative to control (P<0.05), but is much less cytotoxic than Silvazine (P<0.005). CONCLUSION: In this in-vitro study comparing Acticoat, Silvazine and Flamazine, Silvazine shows an increased cytotoxic effect, relative to control, Flamazine and Acticoat. An in-vivo study is required to determine whether this effect is carried into the clinical setting.

A pilot trial of bordered polyurethane dressings, tissue adhesive and sutureless devices compared with standard polyurethane dressings for securing short-term arterial catheters.

OBJECTIVES: To improve arterial catheter (AC) securement and reduce AC failure; to assess feasibility of a large randomised controlled trial. DESIGN, SETTING AND PARTICIPANTS: A four-arm, parallel, randomised, controlled, non-blinded pilot trial with 195 intensive care patients taking part, in a tertiary referral hospital in Brisbane, Australia from May to November 2012. INTERVENTIONS: Standard polyurethane (SPU) dressing (controls); bordered polyurethane (BPU) + SPU dressing; tissue adhesive (TA) + SPU dressing; and sutureless securement device (SSD) + SPU dressing (no sutures used). MAIN OUTCOME MEASURES: AC failure, ie, complete dislodgement, occlusion (monitor failure, inability to infuse or fluid leaking), pain or infection (local or blood). RESULTS: Median AC dwell time was 26.2 hours and was comparable between groups. AC failure occurred in 26/195 patients (13%). AC failure was significantly worse with SPU dressings (10/47 [21%]) than with BPU + SPU dressings (2/ 43 [5%]; P = 0.03), but not significantly different to TA + SPU (6/56 [11%]; P = 0.18) or SSD + SPU (8/49 [16%]; P = 0.61). The dressing applied at AC insertion lasted until AC removal in 68% of controls; 56% of BPU + SPU dressings; 73% of TA + SPU dressings; and 80% of SSD + SPU dressings (all P > 0.05). There were no infections or serious adverse events. Patient and staff satisfaction with all products was high. Median costs (labour and materials) for securement per patient were significantly higher in all groups compared with the control group (SPU, $3.48 [IQR, $3.48-$9.79]; BPU + SPU, $5.07 [IQR, $5.07-$12.99]; SSD + SPU, $10.90 [IQR, $10.90-$10.90]; TA + SPU, $17.70 [IQR, $17.70-$38.36]; all P < 0.01). CONCLUSION: AC failure occurred significantly less often with BPU + SPU dressings than with SPU dressings. TA + SPU and SSD + SPU dressings should be further investigated and compared with BPU + SPU dressings as controls. The novel approach of TA + SPU dressings appeared safe and feasible.

Interposition arthoplasty of the first carpal-metacarpal joint using suture anchor and polydioxanone ribbon.

Osteoarthritis of the first carpal-metacarpal joint is common, and there are a number of procedures described to deal with it. We describe a technique used in our practice and evaluate the outcomes.