Venous Line Research Articles

Analyzing the Evolution of Needle and Ultrasound Probe Manipulation Skills of Interventional Radiology Trainees With Time and Experience.

To test the hypothesis that hand motion analysis can measure the progression of needle and ultrasound probe manipulation skills of interventional radiology trainees in central venous line placement. An expert cohort of 6 interventional radiologists and 4 anesthesiologists and a trainee cohort of 6 novice trainees (<50 central lines) and 5 experienced trainees (>50 central lines) performed simulated central venous access. Four novices and 1 experienced trainee repeated the task 1 year later. An electromagnetic motion tracking system tracked the needle hand and ultrasound probe. Path length, translational, and rotational movements were calculated separately for the needle hand and probe sensor. These metrics were used to calculate motion metrics based scores on a scale of 0 to 3 for each sensor. Nonparametric statistics were used, and the data are reported as median ± interquartile range. Comparing novice and experienced trainees, there was a significant difference in probe scores (experienced vs. novice: 1 ± 2 vs. 0 ± 0, P = 0.04) but not in needle-hand scores (1 ± 1.5 vs. 0 ± 1, P = 0.26). Trainees showed a significant increase in probe scores at the 1-year follow-up (baseline vs. follow-up: 0 ± 1 vs. 2.5 ± 1.8, P = 0.003), but no significant difference was observed in the needle manipulation metrics. Experts differed significantly from experienced trainees for all metrics for both sensors (P < 0.05), with the exception of the path length of the probe. Acquisition of improved dexterity of the probe may occur before improvement in the dexterity with the needle hand for interventional radiology trainees.

Enteral nutritional strategy during therapeutic hypothermia: who? when?what?

There are no guidelines regarding enteral feeding (EF) of infants with hypoxic-ischemic encephalopathy (HIE) during and shortly after therapeutic hypothermia; consequently, clinical practice is, to date, still variable. The objective of this study is to assess whether a minimal EF strategy during therapeutic hypothermia may be associated with a shorter time to full EF of infants with HIE and to identify the clinical variables that independently affect the time to full EF. A retrospective study, covering the period from 1 January 2015 to 30 June 2022 was performed at the Neonatal Intensive Care Unit of the Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, which compared infants with HIE who received minimal EF during therapeutic hypothermia with those who did not. Seventy-eight infants received minimal EF during therapeutic hypothermia, while 75 did not. Infants who were fed reached full EF significantly faster than those who were not. Moreover, they received parenteral nutrition and maintained central venous lines for a shorter time. A multivariate analysis, taking into account the variable of clinical severity, confirmed that minimal EF is an independent beneficial factor for reaching full EF in a shorter time and mechanical ventilation and seizures are independent factors for a longer time to full EF. Minimal EF during therapeutic hypothermia is associated with a shorter time to full EF in stable infants with HIE. Further prospective studies are needed to better define the enteral nutrition strategy for infants during therapeutic hypothermia, regardless of the severity of clinical conditions.

Identifying intraoperative events in a simulated laparotomy video: a multinational study of inattentional blindness among anesthesiologists.

Medical errors may be occasionally explained by inattentional blindness (IB), i.e., failing to notice an event/object that is in plain sight. We aimed to determine whether age/experience, restfulness/fatigue, and previous exposure to simulation education may affect IB in the anesthetic/surgical setting. In this multicentre/multinational study, a convenience sample of 280 anesthesiologists watched an attention-demanding video of a simulated trauma patient undergoing laparotomy and (independently/anonymously) recorded the abnormalities they noticed. The video contained four expected/common abnormalities (hypotension, tachycardia, hypoxia, hypothermia) and two prominently displayed unexpected/rare events (patient's head movement, leaky central venous line). We analyzed the participants' ability to notice the expected/unexpected events (primary outcome) and the proportion of expected/unexpected events according to age group and prior exposure to simulation education (secondary outcomes). Anesthesiologists across all ages noticed fewer unexpected/rare events than expected/common ones. Overall, younger anesthesiologists missed fewer common events than older participants did (P = 0.02). There was no consistent association between age and perception of unexpected/rare events (P = 0.28), although the youngest cohort (< 30yr) outperformed the other age groups. Prior simulation education did not affect the proportion of misses for the unexpected/rare events but was associated with fewer misses for the expected/common events. Self-perceived restfulness did not impact perception of events. Anesthesiologists noticed fewer unexpected/rare clinical events than expected/common ones in an attention-demanding video of a simulated trauma patient, in keeping with IB. Prior simulation training was associated with an improved ability to notice anticipated/expected events, but did not reduce IB. Our findings may have implications for understanding medical mishaps, and efforts to improve situational awareness, especially in acute perioperative and critical care settings.

Calcium-Free Dialysate Hemodialysis: A Simplified Approach.

Intermittent hemodialysis (HD) in high-bleeding-risk patients presents a challenge as circuit anticoagulation using heparin is contraindicated in such cases. Recently, the use of calcium-free citrate-containing dialysate with calcium supplementation emerged as a viable alternative to heparin-circuit anticoagulation. This is a retrospective, monocentric study to evaluate dialysis efficacy using calcium-free citrate-containing dialysate with calcium reinjection into the venous line in hemodialysis patients at risk of bleeding. A total of 53 patients were analyzed: 52 had a temporary contraindication to systemic anticoagulation (active bleeding or surgical intervention), and 1 chronic HD patient had prolonged bleeding time due to inoperable arteriovenous fistula stenosis. Only 7 out of 79 dialysis sessions performed were prematurely terminated (vascular access dysfunction). The median dialysis time was 240 min (range: 150-300). The chronic dialysis patient had 108 sessions with no premature termination. Frequent monitoring of ionized calcium was performed throughout the dialysis sessions: levels remained stable at T0 and T + 60 min (1.08 ± 0.08 mmol/L) and slightly increased at the end of the dialysis session (1.19 ± 0.13 mmol/L), remaining within normal limits. Target postfilter ionized calcium <0.4 mmol/L was achieved in all sessions (0.31 ± 0.07 mmol/L). There were no cases of symptomatic hypo-/hypercalcemia and no need for calcium infusion rate adjustment throughout the sessions. Hemodialysis with calcium-free citrate-containing dialysate and calcium reinjection into the venous line is efficient and safe in HD patients with contraindications to systemic anticoagulation.

Probiotic use in pediatric kidney transplant recipients: What are current practices, and are they evidence-based? A pediatric nephrology research consortium study.

Probiotics are living microorganisms that may confer health benefits to their host if administered in sufficient quantities. However, data on the use of probiotics in transplant recipients are scarce. This multi-center survey of pediatric nephrologists aimed to examine variations in practice regarding the use of probiotics in pediatric kidney transplant recipients. The survey was conducted via a 10-item questionnaire (developed in Survey Monkey) administered to pediatric nephrologists participating in the Pediatric Nephrology Research Consortium meeting in April 2023. Sixty-four pediatric nephrologists completed the survey. Twenty-seven (42.2%) respondents reported having prescribed probiotics to pediatric kidney transplant recipients. The primary reason for probiotic use was the treatment of antibiotic-associated diarrhea (n = 20), with other reasons including recurrent Clostridium difficile infection (n = 15), general gut health promotion (n = 12), recurrent urinary tract infections (n = 8), and parental request (n = 1). Of those who prescribed probiotics, 48.1% held them during periods of neutropenia and 14.8% during central venous line use. Of the 64 respondents, 20 reported the lack of safety data as a concern for using probiotics in kidney transplant recipients. Pediatric nephrologists are increasingly prescribing probiotics to pediatric kidney transplant recipients; nevertheless, substantial practice variations exist. The paucity of safety data is a significant deterrent to probiotic use in this population.

Quantifying potential fluid transfused through pressure monitoring and circuit flushes in pediatric ECMO patients.

Pressure monitoring on pediatric Extracorporeal Membrane Oxygenation (ECMO) circuits is used to aid in the evaluation of patient hemodynamics and circuit health. Extracorporeal Life Support Organization (ELSO) recommends monitoring pressures on the venous line, pre-, and post-oxygenator. In order to keep pressure ports patent, crystalloid can be used as a flush. The fluid transfused to the patient through these lines can be challenging to quantify accurately due to variance in clinician practice. Currently, there is no published data or practice suggestions on this topic. In Vitro experiments using Edwards True Wave transducers and pressure bags were constructed, allowing for common negative and positive pressures to be simulated. Passive volume infused through the transducer as well as intermittent active flushing by pulling the snap tab were measured and the volumes were recorded. When the pressure transducer and associated tubing are kept patent by using a pressurized IV bag, per the instructions for use, the daily volume transfused was found to be 319.6mL or close to a typical neonate's total blood volume. Rather than using passive or active flushing, the use of automated syringe pumps can reduce the transfused volume to 24 mL per day. Further study is recommended to develop and publish best practices.

#1250 Measurement of ionized calcium with a point-of-care ionometer during treatment with etelcalcetide

Abstract Background and Aims Etelcalcetide is an intravenous calcimimetic indicated for the treatment of mineral and bone disorders in hemodialysis patients by lowering parathyroid hormone (PTH), calcium and phosphorus. The assessment of ionized calcium versus total calcium has not yet been studied during treatment with etelcalcetide, and there are no real data on the occurrence of hypocalcemia as measured by ionized calcium in the pre- and post-hemodialysis period during treatment with etelcalcetide. The aim of this study was to describe the time course of ionized and total serum calcium levels during chronic treatment with etelcalcetide and to assess the occurrence of hypocalcemia in patients treated with etelcalcetide by measuring ionized calcium levels. Method This was an observational, non-interventional, prospective, single-arm phase IV study. A total of 20 chronic hemodialysis patients (15 men and 5 women) aged 55.9 ± 18.2 years undergoing dialysis for 5.5 ± 4.3 years in two hemodialysis centers of the University Medical Centre Ljubljana were enrolled in the study between January 2020 and March 2021. All patients received etelcalcetide as a bolus injection into the venous line of the dialysis circuit three times a week, immediately after each hemodialysis session. Ionized calcium levels were determined using a point-of-care ionometer (GEM Premier 3000) before starting treatment with etelcalcetide prior to dialysis, then during treatment in the first week before and after dialysis, then once a week until the maintenance phase was reached and at least once a month thereafter. Hypocalcemia was defined by a pre-dialysis ionized calcium concentration below 0.90 mmol/L. The corrected total calcium values was measured prior to dialysis at least once a month according to routine clinical practice. The data of all these patients were included in the analysis, except for one, who underwent a kidney transplantation after receiving only 4 doses of etelcalcetide. Results We demonstrated that both corrected total calcium and ionized calcium before dialysis decreased over time during treatment with etelcalcetide. Of 240 measurements of ionized calcium with a point-of-care ionometer at the bedside, the concentration of ionized calcium was below 0.90 mmol/L three times in two patients (0.81, 0.84, 0.85). In one patient, we increased a calcium level in the dialysate from 1.50 to 1.75 mmol/L and in the other from 1.25 to 1.50 mmol/L. In addition, we observed 2 further measurements of ionized calcium of 0.90 mmol/L and 18 measurements between 0.91 and 0.96 mmol/L. However, this corresponds to 1.25% of hypocalcemias with ionized calcium below 0.90 mmol/L and 8.3% of those with calcium between 0.90 and 0.96 mmol/L. As calcium concentration in the bath increased, the pre-dialysis calcium concentrations also appeared to increase. At the beginning of the study, the calcium concentration in the dialysate was 1.5 mmol/L in 16 of 20 patients. 2 patients were treated with a calcium concentration in the dialysate of 1.75 mmol/L and 2 others with 1.25 mmol/L. The proportion of patients using higher dialysate calcium concentration was higher at the end of the study, as two patients switched to 1.75 mmol/L, and one from 1.25 to 1.50 mmol/L. This probably indicates a co-intervention triggered by a reduction in serum calcium levels prior to dialysis during treatment with etelcalcetide. Visual comparisons of the time course of ionized and corrected calcium concentrations before dialysis during chronic treatment with etelcalcetide in 19 patients showed a good correlation between point-of-care ionized calcium and routinely measured total calcium. Conclusion A point-of-care ionometer for the determination of ionized calcium at the bedside has the potential to guide etelcalcetide therapy by optimizing serum calcium levels and also to prevent potentially threatening hypocalcemia.

#1647 Clinical insights into incremental hemodialysis: a retrospective analysis of patient persistence and outcomes

Abstract Background and Aims Incremental haemodialysis has been proposed as an alternative to standard thrice-weekly haemodialysis for incident patients with significant residual kidney function. Definition is not unique, but it is mostly intended as twice weekly dialysis. Its diffusion is not known since there are no public registers in Europe, but it is adopted in some dialysis facilities, while in others is not, with geographical differences. In our centre incremental haemodialysis in adopted for some patients, based on the clinical judgement, without a strict protocol. We retrospectively analysed clinical outcomes of the incident patients of the last 36 months, to understand which patients may benefit more from this approach, how long it is viable and the clinical outcomes. Method Retrospective observational analysis of incident patients of the last 36 months, without serious rapidly evolving disease. Focus was on persistence in twice-weekly dialysis, nutritional parameters, residual kidney function, hospital admissions and economic considerations. 36 patients started haemodialysis with a 2-times per week schedule while 13 with full dose dialysis. At baseline, there were no significant differences on age, sex, serum albumin or vascular access. 5 patients in full dose group were anuric for bilateral nephrectomy or rapidly progressive kidney disease, while all patients in incremental group had significant residual kidney function (average creatinine clearance: 7.1 ml/min). Results During the follow up period, 19/36 patients’ weekly dialysis sessions were incremented to three after a median time of 280 days, and 17/36 were still on 2-dialysis with a median follow-up time of 228 days. The reason for transition to three dialysis per week was residual kidney function loss except for a case of pericarditis. Persistence in incremental dialysis was &amp;gt;80% at 6 months and 44% at 1 year (Fig. 1a). We observed a significantly reduced persistence in patients with low ultrafiltration at 2nd month of dialysis (&amp;lt;1.7% of weight per session – 1 kg for a 60 kg patient-) and a reduced persistence with pre-dialysis systolic blood pressure &amp;lt;150 mmHg at 2nd month (Fig. 1b-c). Persistence was not different in more frail patients (elderly, dialyzed with a central venous line or with lower baseline albumin). Serum albumin increase was higher in patients in incremental haemodialysis at 6 months, with a borderline statistically significant difference, and similar at 1 year (Fig. 2a-b). The average weight was stable in both groups (Fig. 2). Hospital admissions were lower in the incremental group, and number of days of hospitalization per 1000 patients’ days were lower (24 vs 41 days). Thanks to the incremental approach, about 1600 dialysis sessions were avoided for the patients included in the analysis, with significant reduction of economic impact for the public healthcare and the possibility to treat more patients. Data was insufficient to make conclusions on kidney function preservation. Conclusion Incremental approach is valid in our experience. These data give useful information on how long we can expect patients to persist in 2-weekly dialysis and on which patients might benefit more and longer of this approach. The patients with better volume control, which reflect in adequate blood pressure control and low ultrafiltration rate, show a significantly longer persistence in incremental dialysis. The approach is valid also for frail patients. We also found better albumin and lower hospital admission rates that could be related with a reduced health-care exposition and better overall patients’ well-being, with adequate uremic symptoms control. The reduction on the hospital admissions has been already observed, while the albumin better rise is a new finding and should be confirmed in a randomized or at least larger study. Waiting for the results of the on-going randomized clinical trials, incremental haemodialysis might be the new standard-of-care for a subset incident haemodialysis patients.

#1351 Assessment of safety and efficacy of expanded hemodialysis in comparison to HDF

Abstract Background and Aims In end-stage kidney disease, solutes with a wide spectrum of molecular weight, called uremic toxins, are retained due to impaired kidney cleansing capacity. Particularly, the retention of toxins in the middle molecular weight range 15–45 kDa might negatively affects multiple organ systems and metabolic pathways. The removal of such large uraemic toxins is still a challenge. HDF has produced some results although large convective volume, optimal vascular access to increase the blood flow rate and strict water quality management are required. Medium Cut-Off, high Retention Onset membrane have been recently developed introducing the concept therapy called “expanded haemodialysis” (HDx). Furthermore, vitamin E-coated membrane has potential beneficial effects on inflammation and oxidative stress. Method A prospective longitudinal single-center study was conducted for 3 months among 18 chronic haemodialysis patients. Patients were randomly assigned into either HDF with high flux membrane or HDx with Theranova or ViE-X membrane. The primary goal was to assess albumin loss among the three types of dialyzers. Secondary goals included assessment of depurative efficacy for uraemic toxins and clinical outcomes. Throughout the treatment, a proportional part of the dialysis fluid was collected to quantify albumin loss. Blood samples were taken before and after dialysis session in order to calculate the Removal Ratio and at two different intradialytic timepoints from arterial and venous line of the circuit in order to calculate instantaneous clearance. Results Mean albumin loss was significantly higher in patients undergoing HDx with Theranova membrane (ANOVA, p&amp;lt;0.001) without any difference in serum albumin concentration among the three groups. Instantaneous clearance of small and middle molecules was significantly higher in patients undergoing HDF, but we didn't find differences in removal ratio. Reduction of Erythropoietin resistance index was observed in patients treated with ViE-X membrane but it was related to their lower dialysis vintage. Conclusion HDx with Theranova membrane was associated with higher albumin loss without any effect on pre-dialysis serum albumin. Moreover, patients treated Theranova membrane, in the presence lower Qb, lower convective dose and lower instantaneous clearance reached same dialysis efficacy compared to HDF.

#1967 Towards the design optimisation of catheters for paediatric dialysis using a bioengineering approach

Abstract Background and Aims Central venous lines (CVLs) used for haemodialysis (HD) in children are associated with a high complication rate, leading to inadequate dialysis and need for a line replacement in nearly 45% of children on HD. This high complication rate may be due to poor CVL configurations, designed without considering specific anatomical differences between children and adults. Using a bioengineering approach, we aim to provide a fluid dynamics characterization of different CVL models commonly used in children to establish an association between CVL design and clinical complications, and to improve CVL performance by optimising their design. Method Computational fluid dynamics (CFD) using modelling and simulations is a powerful engineering tool that use computers to study complex systems, applying mathematics, physics and computer science. Four models of CVLs of varying designs and sizes (6.5Fr, 8Fr, 10Fr and 14Fr) were scanned by microCT to reconstruct computational models. CFD analyses were set up to simulate blood flow within the CVLs under both ideal and realistic models of superior vena cava. A variety of flow rates, routinely used in clinical practice, were applied to study the whole range of working conditions. Haemodynamic features that cannot be measured in vivo such as high shear stresses and large areas of stagnation, were analysed. CFD findings were compared to clinical outcomes (n = 26 patients with 57 lines) and to the blood clots distribution of CVLs removed from patients (n = 8). Fluid dynamics characteristics of the CVLs studied were used to set up a preliminary design optimisation process of a 6.5F CVL model. Using sampling methods, a variety of CVL designs were created starting from the original model and results were compared. Results In all the simulated CVLs, the arterial lumens showed the highest stagnation and recirculation areas. The role of arterial tip configuration was negligible for the blood flows and the proximal side holes played a major role for blood aspiration being also subject to the highest levels of shear stress, regardless of the design. In all the anatomical models, blood velocity increased after catheter insertion (Fig. 1a) together with wall shear stresses. CFD results were in accordance with the clinical data which showed a higher recurrence rate of thrombosis for the 8Fr and 10Fr CVLs. Also, microCT of the CVLs removed due to complications confirmed presence of thrombosis at the catheter tips. Results suggest that shear stress is the parameter most strongly related to clinical complications. The preliminary design optimisation study was used to find the parameters which have the highest influence on the CVL performance. Preliminarily optimised designs of the 6.5F model showed a better haemodynamic performance, reducing stagnation areas (Fig. 1b). Conclusion Characterisation of the fluid dynamics of commercially available CVLs explains some of the clinical outcomes experienced by patients. Identification of potential design-related complications in CVLs has allowed to set up the optimisation process which will lead to new CVL designs with improved blood flow distribution and minimal damage to blood cells. Funding Kidney Research UK, PhD fellowship and MedTech grants.

#2548 In vitro evaluation of proenkephalin kinetics in hemofiltration and hemodialysis

Abstract Background and Aims Proenkephalin A 119-159 (penKid) is a stable surrogate marker for enkephalins (endogenous opioids regulating kidney function). PenKid plasma concentration correlates to GFR and increases in AKI, for this reason it can be used for prediction and diagnosis of AKI (even subclinical forms) and need of RRT. Furthermore, it seems to be also a reliable biomarker to predict the successful liberation from RRT and may therefore aid in the successful weaning of patients from RRT. PenKid has the perk of maintaining stable its concentration during RRT, suggesting that is barely filtered, in contrast to other biomarkers. However, with its small size of 4.5 kDa, penKid can be assumed to be freely filtered through the glomerulus and dialysis membranes. To address the issue about stable penKid plasma concentrations in RRT (no extracorporeal removal or increased production in response to impaired kidney function), we planned ex vivo experiments simulating different conditions of RRT. The aim of this study is to determine the sieving coefficient and the diffusive clearance of the penKid molecule in conditions of in vitro continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodialysis (CVVHD), respectively. Method The lyophilized peptide was solved in 20 mM Dipotassium phosphate, 6 mM Disodium EDTA [pH 8], avoiding concentrations higher than 1 mg/mL. The compound was diluted in 50 mL of plasma to ensure homogeneous distribution. For each experimental modality, a batch of blood of 1000 mL with adjusted hematocrit at 30% and albumin concentration of 3 g% was utilized. Blood was spiked with lyophilized synthetic penKid to achieve two target concentrations of 150 and 500 pmol/L in CVVH and CVVHD modalities, respectively. Blood was adjusted for a volume of 1000 mL, maintained at 37° and continuously stirred during the experiments. CVVH was performed with blood flow (QB) = 150 mL/min and ultrafiltration rate (QUF) = 20 mL/min to reproduce a filtration fraction of 20%. The ultrafiltrate was reinfused in the venous line to maintain initial volume. This allowed to define convective clearance and solute sieving coefficient in pure convective mode. CVVHD was performed with QB = 150 mL/min and dialysate flow (QD) = 35 mL/min (Net QUF = 0 mL/min). This allowed the calculation of diffusive clearance. A polysulfone dialyzer (AV1000 FMC, Bad Homburg, Germany) was utilized. Samples were taken at 10, 30, 60 minutes from the initiation of the circulation, in both modalities. Results Initial penKid concentrations in blood corresponded to the desired targets in all the experiments. Sieving coefficients displayed values between 0.69 and 1.5 and they appear to remain stable over time (Fig. 1). Diffusive clearance displayed values between 35 and 15.7 mL/min. Values appear to present a slight decrease over time (Fig. 2). The observed variability can be attributed to several factors: difference in plasma protein interference in various moments of the experiments, difference in concentration of penKid in plasma water versus plasma or blood, variability in the sample measurements. Conclusion Significant removal of penKid can be obtained by extracorporeal therapies both in convection (CVVH) and diffusion (CVVHD). Further investigation is needed to assess if these findings are confirmed during in vivo treatments in which penKid kinetics is affected by generation, elimination and changes in distribution volume.

Can a low prime volume arterial filter be used as an alternative for a venous bubble trap in minimal extracorporeal circulation? An in vitro investigation.

During cardiac surgery the use of a minimal extracorporeal circulation (MiECC) system may reduce the adverse effects for the patient. This is probably caused by reduced inflammation and hemodilution. For the use of a MiECC circuit, a venous bubble trap (VBT) is warranted for safety reasons. The aim of this study was to assess if an arterial filter with a small prime volume has the same (or better) air removal capacities as a VBT in a MiECC circuit and subsequentially may be used as an alternative. In an in vitro study, air removal properties were compared between the arterial filter and three VBT's on the market, VBT160 (Getinge), VBT 8 (LivaNova and VARD (Medtronic). In a MiECC circuit, the filter devices were placed in a venous position and challenged with massive and micro air. Gaseous microemboli (GME) were measured with a bubble counter proximal and distal of the VBT device. More than 99.9 % of the air was removed after a bolus air challenge by all VBT's. Both the VARD and the AF100 showed better GME removal properties (not significant for the AF100) compared to the other devices. All filters showed GME generation after a challenge with massive air. Compared to the other filters, only the VARD showed no passing of larger bubbles when a volume of 50mL of air was present in the filter. The AF100 seems to be a safe and low prime alternative for use in a MiECC system as a venous air trap. A word of caution, placement of the AF100 arterial filter in the venous line is off label use.

Can regional anticoagulation with calcium-free dialysate be extended to maintenance hemodialysis?

Regional anticoagulation in hemodialysis avoids the use of heparin, which is responsible for both hemorrhagic and non-hemorrhagic complications. Typically, blood is decalcified by injecting citrate into the arterial line of the extracorporeal circuit. Calcium-free dialysate improves anticoagulation efficacy but requires injection of a calcium-containing solution into the venous line and strict monitoring of blood calcium levels. Recent improvements have made regional anticoagulation with calcium-free dialysate safer and easier. (1) Adjusting the calcium injection rate to ionic dialysance avoids the risk of dyscalcemia, thus making unnecessary the monitoring of blood calcium levels. This adjustment could be carried out automatically by the hemodialysis monitor. (2) As calcium-free dialysate reduces the amount of citrate required, this can be supplied by dialysate obtained from currently available concentrates containing citric acid. This avoids the need for citrate injection and the risk of citrate overload. (3) Calcium-free dialysate no longer needs the dialysate acidification required for avoiding calcium carbonate precipitation in bicarbonate-containing dialysate. Regional anticoagulation with calcium-free dialysate enables an acid- and heparin-free procedure that is more biocompatible and environmentally friendly than conventional bicarbonate hemodialysis. The availability of specific acid-free concentrates and adapted hemodialysis monitors is required to extend this procedure to maintenance hemodialysis.

Direct Species Identification in Positive Blood Culture Bottles From Patients With Hematologic Malignancies.

Background In patients with hematologic malignancies, faster species identification is particularly important in the management of bloodstream infection because of their immunocompromised and neutropenic status. In the present study, we analyzed direct species identification in patients with hematologic malignancies, and the factors that might influence the results of species identification. Methods We performed direct species identification using a Sepsityper® kit (Bruker Corporation, Billerica, Massachusetts, United States) and compared the results with a conventional method in patients with hematologic malignancies. Forty-five positive blood culture bottles containing single microorganisms from 37 patients were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). And patients' clinical data were compared between the groups with spectral scores at acceptable and unacceptable levels. Results Direct species identification correctly identified 42 of 45 isolates and three were misidentified.While 35 of 45 isolates showed a spectral score ≥1.7 (acceptable identification), 10 isolates had a spectral score <1.7 (unacceptable identification) including three misidentified isolates. The group with a spectral score ≥1.7 had significantly lower white blood cell (p<0.01), neutrophil (p<0.01), and platelet (p<0.01) counts in addition to more frequent central venous (CV) line insertion (p=0.01). Multivariate analysis revealed that pathogen type (gram-positive or negative) and CV line insertion were associated with spectral scores. Conclusion Direct species identification using the Sepsityper kit is an upcoming approach for blood culture bottles, which were flagged as positive even in patients with hematologic malignancies when the spectral score was ≥ 1.7. Our study also indicates that direct identification is more accurate in patients with CV lines, and may be less accurate when gram-positive bacteria are detected.

763 Is Central Venous Catheter the Main Culprit for Clinically Significant Venous Thromboembolism in Burn Patients

Abstract Introduction Venous thromboembolism (VTE) is a significant clinical problem for burn patients. The incidence of VTE has been reported as 0.25% to 47.1%. Known risk factors include large burn size, increasing age, male gender, active smoker or alcohol use, blood transfusion and surgeries. Central venous line (CVL) use is also a known risk factor for VTE. With all the known factors, we retrospectively analyzed our patients with VTE. Methods Retrospective chart review was performed on a single institution burn center in the calendar year of 2022. Pediatric patients were excluded. Following data were collected: age, burn size, mechanism, length of hospital stays, VTE diagnosis, VTE chemoprophylaxis, and central venous line days. VTE diagnosis was made using CT venogram or ultrasound. This project was a quality improvement initiative. Results There were 420 patients in the study period. Of all the admitted patients, there were 6 patients diagnosed with 7 VTE. One patient had 2 separate diagnoses of VTE at 2 distinct period and anatomical site. The incidence of VTE is 1.7%. Upon further chart review, all the VTE were at the site of central venous catheters. All the patients were on VTE chemoprophylaxis. The correlation between burn size, age, length of hospital stay and VTE was not significant. Conclusions Risk of VTE is high in burn patients due to the correlation with the Virchow’s Triad. All the patients admitted to the burn unit are placed on chemoprophylaxis unless contraindicated. The 7 patients diagnosed with VTE were on chemoprophylaxis. All the VTE were at the site of central venous catheter insertion sites, which is a known complication of catheters. The incident of 1.7% is on par with VTE incidents of burn patients, but much less than VTE caused by central venous catheters in non-burn patients. Large multicenter data collection is needed to validate this finding. Applicability of Research to Practice Directly appliable

Venous-Only Transcatheter Closure: A Safe and Effective Strategy for Patent Ductus Arteriosus

Objectives: This study aimed to assess the feasibility and effectiveness of transcatheter device closure of patent ductus arteriosus (PDA) exclusively through an isolated venous route. Methodology: A retrospective descriptive study was conducted at the Rawalpindi Institute of Cardiology. Patient data from 2019 to 2023 undergoing PDA closure using transcatheter devices were analyzed. PDA diagnosis was established via echocardiography, and the procedure was performed solely through a venous line under fluoroscopy, omitting the traditional method of using both arterial and venous lines. Results: A total of 212 patients underwent transcatheter PDA closure through a venous-only route, with ages ranging from 6 months to 14 years. The mean weight was 10.07 kg (range: 5 kg to 27 kg, SD 4.43). The average procedure time was 30 ± 10.3 minutes (range: 15.0 to 65 minutes), and fluoroscopy time was 5.4 ± 3.18 minutes (range: 2.1 to 19 minutes). Immediate closure was achieved in all patients, with no residual leaks or device embolization observed. Additionally, there were no reported complications such as arrhythmia, vascular access issues, or significant blood loss. No cases of aortic or pulmonary stenosis were identified, and no deaths occurred. All patients were discharged within 48 hours post-procedure. Conclusion: Transcatheter closure of PDA exclusively through the venous route, without the use of an arterial line, demonstrates itself as an effective and safe method for PDA closure.

Assessment of the CLOT (children's likelihood of thrombosis) real-time risk prediction model of hospital-associated venous thromboembolism in children with congenital heart disease

BackgroundChildren with congenital heart disease (CHD) are at high risk for hospital-associated venous thromboembolism (HA-VTE). The children's likelihood of thrombosis (CLOT) trial validated a real-time predictive model for HA-VTE using data extracted from the EHR for pediatric inpatients. We tested the hypothesis that addition of CHD specific data would improve model prediction in the CHD population. MethodsModel performance in CHD patients from 2010 to 2022, was assessed using 3 iterations of the CLOT model: 1) the original CLOT model, 2) the original model refit using only data from the CHD cohort, and 3) the model updated with the addition of cardiopulmonary bypass time, STAT Mortality Category, height, and weight as covariates. The discrimination of the three models was quantified and compared using AUROC. ResultsOur CHD cohort included 1457 patient encounters (median 2.0 IQR [0.5-5.2] years-old). HA-VTE was present in 5% of our CHD cohort versus 1% in the general pediatric population. Several features from the original model were associated with thrombosis in the CHD cohort including younger age, thrombosis history, infectious disease consultation, and EHR coding of a central venous line. Lower height and weight were associated with thrombosis. HA-VTE rate was 12% (18/149) amongst those with STAT Category 4-5 operation versus 4% (49/1256) with STAT Category 1-3 operation (P < .001). Longer cardiopulmonary bypass time (124 [92-205] vs. 94 [65–136] minutes, P < .001) was associated with thrombosis. The AUROC for the original (0.80 95% CI [0.75-0.85]), refit (0.85 [0.81-0.89]), and updated (0.86 [0.81-0.90]) models demonstrated excellent discriminatory ability within the CHD cohort. ConclusionThe automated approach with EHR data extraction makes the applicability of such models appealing for ease of clinical use. The addition of cardiac specific features improved model discrimination; however, this benefit was marginal compared to refitting the original model to the CHD cohort. This suggests strong predictive generalized models, such as CLOT, can be optimized for cohort subsets without additional data extraction, thus reducing cost of model development and deployment.

Educational Program on Nurses Knowledge about Blood Exchange Transfusion in Neonatal Care Units

Background: Exchange transfusion entails the sequential drawing and injecting of blood aliquots via peripheral or central venous and arterial lines. Notably, arterial lines—either peripheral or umbilical—should not be used for donor blood injections; rather, they should only be used for baby blood withdrawal. To ascertain the Nurses' Knowledge of Blood Exchange Transfusion in Neonatal Intensive Care Units Educational Program. Methods: Designing a quasi-experimental using (non-probability) To ascertain the impact of a training program on nurses' performance with regard to blood exchange transfusion, purposeful sampling was used. The "Statistical Package for Social Science (SPSS) software for Windows (Version 26)" is used to analyze data. Results: This result showed that 33.3%(10) of the study's nurses and 33.3%(10) of the control group's nurses were between the ages of 31 and 35.The study's findings regarding the gender of the nursing staff showed that 53.3% of the participants (19) were female. and of the fifteen participants, 63.3% were men. 50% of the participants are nurses.had a Nursing Institute (15) In terms of general years of experience, 33.3% (10) of the sample had six to ten years of experience, and 3.0% worked in the pediatric department. Conclusion: The study concluded that the nurses’ knowledge about the blood transfusion process before giving the educational program to the patients was poor, and through the intervention and giving the nursing program, their knowledge became good. The reason is due to the effectiveness of the effective programs.

A New Formula for Estimating Insertion Length of Umbilical Catheters in Neonates: An Observational Study

Objective: Current formulae used by clinicians to estimate the insertion length of umbilical catheters are inaccurate. We aimed to derive a new model that could improve accuracy in estimating the insertion length of umbilical catheters. Study design: This was a multi-centre prospective observational study of neonates admitted to neonatal units and needing umbilical line(s) inserted for clinical reasons. Demographic data, catheter-related measurements and a new external length measurement—sternal notch to the umbilicus, were collected at three tertiary-level neonatal units in South Wales, UK. Generalised linear models were used to estimate the fit of the external length, birthweight, gestation and head circumference with catheter length and to derive a formula. The best fit was estimated by comparing r 2 values for each equation. Results: Data from 113 infants for each venous and arterial line were analysed for the new mathematical formulae. For both umbilical arterial catheterisation [[Formula: see text] and umbilical venous catheter (UVC) [[Formula: see text]], a quadratic model based on birthweight was found to have the best fit for predicting the insertion length of the catheters. However, the overall fit for UVCs was poorer for all explanatory variables ( y = estimated insertion length of the umbilical catheter in cm, x = birthweight in kg). Conclusion: Our prospective multi-centre observational study identified a quadratic model based on birthweight as the best fit for estimating the insertion length of umbilical lines in neonates. This is a new finding and further development on earlier birthweight-based linear models.

Prophylactic Treatment of Children with Hemophilia in Sweden.

Hemophilia A/B are caused by deficiency or lack of coagulation factors VIII (FVIII) or factor IX (FIX), respectively, in plasma. A person with hemophilia develops bleeding in the joints and muscles at an early age, which, if left untreated, leads to early arthropathy. Preventive treatment can be achieved by regular (prophylactic) administration of FVIII/FIX. In 1958, this was implemented on a small scale in Sweden with FVIII in patients with severe hemophilia A, and in those with hemophilia B in 1972 when FIX became available. However, there were problems with human immunodeficiency virus and hepatitis infection from contaminated blood products. In the 1990s, recombinant FVIII and FIX concentrates were introduced. The major remaining problems then were the development of inhibitors, and the need for a venous route for the injections in very young children. High-titer inhibitors were treated by immune tolerance induction according to a modified model of the original Bonn high-dose protocol. A central venous line, i.e., Port-A-Cath, has enabled early prophylaxis in many children with poor venous access and has enabled the early start of home treatment with adequate injection frequency. Scoring systems for X-rays, magnetic resonance imaging, and function of joints were developed early in Sweden and have been widely disseminated worldwide, partly with modifications. Extended half-life products with half-life increased three to five times have been developed, which can provide superior bleed protection when dosed once-weekly and can maintain therapeutic trough levels when administered less frequently. The ultimate prophylaxis therapy in the future may be gene therapy.