Prevention of Vascular Access Device-Associated Hospital Onset Bacteremia and Fungemia: A Review of Emerging Perspectives and Synthesis of Technical Aspects.

Significant events impacting healthcare over the last several years have been associated with escalating rates of healthcare-associated infections. This has resulted in increased efforts to reinstitute well-established and evidence-based infection prevention practices, particularly for central line associated bloodstream infections. However, implementation of prevention initiatives beyond central lines has not received the same level of acknowledgement and response as being a considerable risk to patients. This article, authored by infection prevention, infectious disease, and vascular access professionals, provides emerging perspectives and technical aspects associated with the complete lifecycle of a vascular access device. The intent is to provide insight and perspective into enhancing current IP practices in the acute care hospital setting. This will also help prepare hospitals for upcoming broader surveillance and intervention activities aimed at reducing Hospital Onset Bacteremia and Fungemia (HOB) associated with all types of vascular access devices.

Outcomes of brachial artery transposition in hemodialysis patients.

OBJECTIVE: In hemodialysis patients with a difficult access extremity who are not suitable for an arteriovenous fistula or arteriovenous graft creation, the concept of cannulating a superficialized artery for arterial outflow in dialysis sessions has been adopted as a tertiary alternative. However, its long-term patency and complications have not been recognized widely. We report our 16-year experience with hemodialysis access creation using the brachial artery transposition (BAT) technique. METHODS: This single-center retrospective study included consecutive patients who underwent BAT for hemodialysis vascular access between June 1, 2006, and December 31, 2022. The patency of the whole access circuit and the transposed brachial artery itself was evaluated independently. RESULTS: In total, 193 surgical procedures were included. The success rate was 93.2%. The mean operative time was 128 minutes. The median interval from access placement to first cannulation was 21 days. The primary patency rates for BAT were 92.3%, 91.3%, 90.3%, 86.1%, and 71.9% at 1, 2, 3, 5, and 10 years, respectively. The secondary patency rates for BAT were 96.3%, 96.3%, 95.0%, 90.1%, and 74.9% at 1, 2, 3, 5, and 10 years, respectively. The primary patency rates for the whole access circuit were 61.4%, 49.2%, 45.8%, and 26.9% at 1, 2, 3, and 5 years, respectively. The secondary patency rates for the whole access circuit were 85.1%, 83.3%, 82.0%, and 68.6% at 1, 2, 3, and 5 years, respectively. The overall patient survival rates were 79.6%, 69.6%, 54.6%, 36.5%, and 13.4% at 1, 2, 3, 5 and 10 years, respectively. The abandonments of BAT were brachial artery thrombosis (n = 6), pseudoaneurysm (n = 2), aneurysmal change (n = 1), and other reasons (n = 1). The abandonments of the whole access circuit were exhaustion of venous return (n = 26), abandonment of BAT (n = 7), and other reasons (n = 2). Complications were exhaustion of venous return (n = 26), aneurysmal change (n = 12), pseudoaneurysm (n = 6), brachial artery thrombosis (n = 7), impaired wound healing (n = 19), lymphorrhea (n = 9), skin infection (n = 5), hematoma on cannulation (n = 3), and reduced peripheral blood flow (n = 2). CONCLUSIONS: The patency of BAT was excellent, and that of the whole access circuit was adequate, with a few complications. BAT is an effective alternative from a long-term perspective for patients who are unsuitable for conventional hemodialysis access creation.

Recent evaluation by nephrologists is associated with decreased incidence of tunneled dialysis catheter being used at the time of first arteriovenous access creation.

OBJECTIVE: Late primary care provider (PCP) or nephrologist evaluation of patients with progressive kidney disease may be associated with increased morbidity and mortality. Among patients undergoing initial arteriovenous (AV) access creation, we aimed to study the relationship of recent PCP and nephrologist evaluations with perioperative morbidity and mortality. METHODS: We performed a retrospective review of patients from 2014 to 2022 who underwent initial AV access creation at an urban, safety-net hospital. Univariable and multivariable analyses identified associations of PCP and nephrologist evaluations <1 year and <3 months before surgery, respectively, with hemodialysis initiation via tunneled dialysis catheters (TDCs), 90-day readmission, and 90-day mortality. RESULTS: Among 558 patients receiving initial AV access, mean age was 59.7 ± 14 years, 59% were female gender, and 60.6% were Black race. Recent PCP and nephrology evaluations occurred in 386 (69%) and 362 (65%) patients, respectively. On multivariable analysis, unemployed and uninsured statuses were associated with decreased likelihood of PCP evaluation (unemployment: odds ratio [OR], 0.51; 95% confidence interval [CI], 0.34-0.77; uninsured status: OR, 0.05; 95% CI, 0.01-0.45) and nephrologist evaluation (unemployment: OR, 0.63; 95% CI, 0.43-0.91; uninsured status: OR, 0.22; 95% CI, 0.06-0.83) (all P < .05). Social support was associated with increased likelihood of PCP evaluation (OR, 1.81; 95% CI, 1.07-3.08) (all P < .05). Hemodialysis was initiated with TDCs in 304 patients (55%). Older age (OR, 0.98; 95% CI, 0.96-0.99), obesity (OR, 0.38; 95% CI, 0.25-0.58), and nephrologist evaluation (OR, 0.12; 95% CI, 0.08-0.19) were independently associated with decreased hemodialysis initiation with TDCs in patients receiving an initial AV access (all P < .05). Ninety-day readmission occurred in 270 cases (48%). Cirrhosis (OR, 2.5; 95% CI, 1.03-6.03; P = .04), coronary artery disease (OR, 2.31; 95% CI, 1.5-3.57), prosthetic AV access (OR, 1.84; 95% CI, 1.04-3.26), and impaired ambulation (OR, 1.75; 95% CI, 1.15-2.66) were independently associated with increased readmission (all P < .05). Older age (OR, 0.98; 95% CI, 0.97-0.99), prior TDC (OR, 0.65; 95% CI, 0.45-0.94), and unemployment (OR, 0.58; 95% CI, 0.39-0.86) were associated with decreased readmission (all P < .05). Ninety-day mortality occurred in 1.6% of patients. Neither PCP nor nephrologist evaluation was associated with readmission or mortality. CONCLUSIONS: Recent nephrology evaluation was associated with reduced hemodialysis initiation with TDCs among patients undergoing initial AV access creation. Unemployed and uninsured statuses posed barriers to accessing nephrology care.

Creating hemodialysis autogenous access in children and adolescents.

OBJECTIVE: End-stage renal disease (ESRD) in childhood and adolescence is rare, with relatively few published reports of pediatric ESRD vascular access. This study analyzes a 10-year experience creating arteriovenous fistulas (AVFs) in children and adolescents. Our goal is to review our strategy for creating functional autogenous vascular access in younger patients and report our results. METHODS: We retrospectively reviewed data and outcomes for consecutive vascular access patients aged ≤19 years during a 10-year period. Each patient had preoperative vascular ultrasound mapping by the operating surgeon in addition to physical examination. A distal forearm radiocephalic AVF was the first access choice when feasible, and a proximal radial artery inflow AVF was the next option. Demographic data, inflow artery, venous outflow target, and required transposition vs direct AVFs were variables included in the analysis. Primary and cumulative patency were calculated by Kaplan-Meier analysis. RESULTS: Thirty-seven AVFs were created in 35 patients. No grafts were used. Ages were 6 to 19 years (mean, 15 years), and 20 were male. Causes of ESRD included glomerular disease (n = 18) and urinary obstruction or reflux (n = 7), among others. Three had previous AVFs, and 10 were obese. The proximal radial artery supplied AVF inflow in 25 patients and the brachial artery in only seven. Eleven individuals required a transposition and one a vein translocation to the contralateral arm. No patients developed hand ischemia, although two later required banding procedures for high flow. Eleven patients had successful transplants. A single patient died, unrelated to the vascular access. Five AVFs failed. Of these, two had new successful AVFs created, two regained renal function, one was transplanted, and one declined other procedures. Primary and cumulative patency rates were 75% and 85% at 12 months, 70% and 85% at 24 months, and 51% and 85% at 36 months, respectively. Median follow-up was 16 months. CONCLUSIONS: Creating an AVF for hemodialysis is a successful vascular access strategy for pediatric and adolescent patients. Proximal radial artery AVFs provided safe and functional access when a distal AVF was not feasible. Cumulative AVF patency was 85% at 36 months.

Outcomes of prosthetic upper arm arteriovenous graft vs brachiobasilic fistula for hemodialysis access.

OBJECTIVE: Primary arteriovenous access such as radiocephalic and brachiocephalic fistulas are initial choices for creating vascular access in dialysis patients. When neither of these choices is an option, upper arm arteriovenous graft or brachiobasilic transposition is recommended. Although primary fistula is better than prosthetic graft for suitable patients, there is little data to guide the best treatment strategy in the absence of suitable vein for primary access creation. This study identifies factors that influence patency rates and compares outcomes of patients treated with brachiobasilic fistula vs upper arm graft in patients who have failed forearm access or are not candidates for primary access. METHODS: A prospectively maintained database of patients with dialysis-dependent renal failure from 2010 to 2022 was analyzed. Primary, primary assisted, and secondary patency rates were calculated. Incidence rates of complications and reinterventions were compared. RESULTS: There were 148 patients with brachiobasilic fistulas and 157 patients with upper arm grafts. The graft group was older (70.1 ± 14.7 vs 62.5 ± 14.6 years; P = .003) and had a higher incidence of pacemakers (11.9% vs 4.1%; P = .005). Brachiobasilic fistulas had higher 6-month (77.0% vs 64.3%; P = .02) and 1-year (68.2% vs 55.4%; P = .03) primary-assisted patency. Secondary patency rates were better for upper arm grafts at 1-year (82.2% vs 72.3%; P = .05). Access complications of non-maturation and aneurysm were higher in basilic vein transposition (21.6% vs 1.3%; P < .0001; 15.5% vs 6.4%; P = .017). Grafts had higher rates of occlusion (58.0% vs 25.7%; P < .0001). In terms of interventions, upper arm grafts had higher rates of thrombectomy (50.3% vs 18.9%; P < .0001), but there was no difference seen in angioplasty, stent, surgical revision, or steal procedures. Basilic vein transpositions had longer time to cannulation (104.6 ± 81.1 vs 32.5 ± 22.4 days; P < .0001), longer total catheter days (251.1 ± 181.7 vs 72.9 ± 56.3 days; P < .0001), and higher number of procedures to aid maturity (0.7 ± 0.7 vs 0.1 ± 0.3; P < .0001). CONCLUSIONS: In this retrospective analysis, when forearm access or primary arteriovenous access is not an option, basilic vein transposition and upper arm grafts have fairly equivalent primary patency. Primary assisted patency is slightly better in basilic vein fistulas, but secondary patency is better in upper arm grafts at 1 year. Basilic fistulas also had longer time to cannulation, longer total catheter days, and more procedures to aid maturity.

Intraoperative transit time flow measurement predicts maturation of radiocephalic arteriovenous fistulas.

OBJECTIVE: The arteriovenous fistula (AVF) is the first choice for gaining vascular access for hemodialysis. However, 20% to 50% of AVFs fail within 4 months after creation. Although demographic risk factors have been described, there is little evidence on the intraoperative predictors of AVF maturation failure. The aim of this study was to assess the predictive value of intraoperative transit time flow measurements (TTFMs) on AVF maturation failure. METHODS: In this retrospective cohort study, intraoperative blood flow, measured using TTFM, was compared with AVF maturation after 6 weeks in 55 patients. Owing to its significantly higher prevalence and risk of nonmaturation, the radiocephalic AVF (RCAVF) was the main focus of this study. A recommended cutoff point for high vs low intraoperative blood flow was determined for RCAVFs, using a receiver operating characteristic curve. RESULTS: The average intraoperative blood flow in RCAVFs was 156 mL/min. Patients with an intraoperative blood flow equal or lower than the determined cutoff point of 160 mL/min, showed a 3.03 times increased risk of AVF maturation failure after 6 weeks, compared with patients with a higher intraoperative blood flow (P < .001). CONCLUSIONS: The intraoperative blood flow in RCAVFs measured by TTFM provides an adequate means of predicting AVF nonmaturation 6 weeks after surgery. For RCAVFs, a cutoff point for intraoperative blood flow of 160 mL/min is recommended for maximum sensitivity and specificity to predict AVF maturation failure after 6 weeks.

Prehospital central venous catheters.

The use of whole blood in the prehospital setting is increasing. Currently available intraosseous and peripheral venous catheters limit the flow of blood products and fluid during resuscitation. Central venous catheters can be effectively placed in the prehospital environment. Rapid, high-volume infusion of blood products can be lifesaving.

ProGlide-AngioSeal versus ProGlide-FemoSeal for vascular access hemostasis posttranscatheter aortic valve implantation.

BACKGROUND: The hybrid strategy combining plug-based and suture-based vascular closure devices (VCD) was introduced as a promising technique for vascular access hemostasis after transcatheter aortic valve implantation (TAVI) with satisfactory outcomes. However, data comparing two plug-based VCDs each in the combination with a suture-based VCD, namely ProGlide/AngioSeal (P/AS) with ProGlide/FemoSeal (P/FS) VCDs, is still lacking. AIMS: To compare the 30-day outcome of the hybrid strategy using P/AS versus P/FS for vascular access site closure after TAVI. METHODS: A retrospective single-center observational study included 608 patients recruited from a prospective TAVI registry between 2016 and 2022. The composite endpoint was defined as any VCD-related major vascular complications and/or bleeding more than type 1 according to Valve Academic Research Consortium criteria. RESULTS: The current study reported a significantly higher rate of composite endpoint in P/AS group, which was driven by a higher rate of major bleeding (5.4% vs. 1.4%, p = 0.036). We also found a higher rate of VCD-related minor bleeding in P/AS group (16.3% vs. 8.1%, p = 0.013). Successful access site hemostasis was achieved in 71.7% of P/AS group versus 83.1% in P/FS group (p = 0.006). The presence of anterior wall calcification at the access site was significantly associated with the composite endpoint (adj odds ratio 2.49; 95% confidence interval (1.08-5.75), p = 0.032). CONCLUSION: The hybrid strategy for large bore vascular access closure using P/FS showed a potentially better 30-day outcomes compared with P/AS. The presence of anterior calcification at the access site carries a significant risk of VCD-related complications.

Current alternatives to traditional radial approach for coronary interventions: A randomized prospective study of the ulnar and distal radial approaches.

BACKGROUND: The radial artery is the standard access for coronary intervention; however, it is essential to have alternative accesses as it may be used as a conduit during coronary artery bypass grafting or for dialysis fistula. Ulnar and distal radial artery accesses have emerged as alternative accesses for traditional radial artery. AIM: To compare distal radial artery access and ulnar artery access as alternatives to traditional radial artery access regarding safety, efficacy, and success rate. METHODS: Two-hundred patients were included (100 traditional radial [TRA], 50 distal radial [DRA] and 50 ulnar). Access artery follow up ultrasound was performed up to 28 days. RESULTS: Procedural success rate was 97%, 74%, and 92% in the TRA, DRA and ulnar groups, respectively (p < 0.001). Crossover occurred in 3 patients (3%) in TRA, 13 patients (26%) in DRA and 4 cases (8%) in ulnar group (p < 0.001). The most common cause of crossover was failure of artery cannulation. Regarding cannulation time, the mean access time in seconds was 80.19 ± 25.98, 148.4 ± 29.60, 90.5 ± 21.84 in TRA, DRA and ulnar groups, respectively (p < 0.001). CONCLUSIONS: Our study concluded that these new approaches proved to be potential alternatives to traditional radial approach; however, ulnar artery access proved to be superior to distal radial artery access as regards success rate and cannulation time.

The PIGTAIL paradigm for a fast and safe transfemoral transcatheter aortic valve replacement.

Transfemoral transcatheter aortic valve replacement is the preferred primary access route whenever possible. Despite advancements in expertise and delivery system profiles, complications associated with the primary femoral access still significantly affect procedural morbidity and outcomes. The current standard for accurate main access planning involves proper preprocedural evaluation guided by computed tomography. Several baseline clinical and anatomical features serve as predictors for the risk of vascular injury occurring during or after transcatheter aortic valve replacement. In this paper, we aimed at reviewing the most up-to-date knowledge of the topic for a safe transfemoral access approach according to a paradigm we have called "PIGTAIL."

Ultrasound-guided deployment of ProGlide™ device in transfemoral transcatheter aortic valve implantation and risk reduction of vascular complications: A propensity-matched cohort study.

BACKGROUND: ProGlide is a percutaneous suture-mediated closure device used in arterial and venous closure following percutaneous intervention. Risk of vascular complications from use, particularly related to failure in hemostasis, or acute vessel closure, remains significant and often related to improper suture deployment. We describe a technique of ultrasound-guided ProGlide deployment in transfemoral transcatheter aortic valve implantation (TF-TAVI). AIMS: The aim of this study is to assess vascular outcomes for ultrasound-guided deployment of ProGlide vascular closure devices in patients undergoing TF-TAVI. METHODS: We collected relevant clinical data of patients undergoing TAVI in a large volume centre. PRIMARY OUTCOME: main access Valve Academic Research Consortium 3 (VARC-3) major vascular complication. SECONDARY OUTCOME: any major/minor VARC-3 vascular complication, its type (bleed or ischemia), and treatment required (medical, percutaneous, or surgical). We performed inverse weighting propensity score analysis to compare the population undergoing ultrasound-guided versus conventional ProGlide deployment for main TAVI access. Ultrasound technique for ProGlide insertion was performed as described below. RESULTS: Five hundred and seventeen patients undergoing TF-TAVI were included. PRIMARY OUTCOME: In 126 (ultrasound-guided) and 391 (conventional ProGlide insertion), 0% versus 1.8% (p < 0.001) had a major VARC-3 vascular complication, respectively. SECONDARY OUTCOME: 0.8% (one minor VARC-3 bleed) vs 4.1% (13 bleeds and three occlusions) had any VARC-3 vascular complication (major and minor) (p < 0.001). Surgical treatment of vascular complication was required in 0.8% versus 1.3% (p = NS). CONCLUSIONS: Ultrasound-guided deployment of ProGlide for vascular closure reduced the risk of major vascular complications in a large population undergoing TAVI.

Clinical impact of the Kidney Failure Risk Equation for vascular access planning.

BACKGROUND: Risk-based thresholds for arteriovenous (AV) access creation has been proposed to aid vascular access planning. We aimed to assess the clinical impact of implementing the kidney failure risk equation (KFRE) for vascular access referral. METHODS: 16,102 nephrology-referred chronic kidney disease (CKD) patients from the Swedish Renal Registry 2008-2018 were included. The KFRE was calculated repeatedly, and the timing was identified for when the KFRE risk exceeded several pre-defined thresholds and/or the estimated glomerular filtration rate <15 ml/min/1.73m2 (eGFR15). To assess the utility of the KFRE/eGFR thresholds, cumulative incidence curves of kidney replacement therapy (KRT) or death, and decision-curve analyses were computed at 6, 12 months, and 2 years. The potential impact of using the different thresholds was illustrated by an example from the Swedish access registry. RESULTS: The 12-month specificity for KRT initiation was highest for KFRE>50% 94.5 (95% Confidence interval [CI] 94.3-94.7), followed by KFRE>40% 90.0 (95% CI 89.7-90.3), while sensitivity was highest for KFRE>30% 79.3 (95% CI 78.2-80.3) and eGFR<15 ml/min/1.73m2 81.2 (95% CI 80.2-82.2). The 2-year positive predictive value was 71.5 (95% CI 70.2-72.8), 61.7 (95% CI 60.4-63.0) and 47.2 (95% CI 46.1-48.3) for KFRE>50%, KFRE>40%, and eGFR<15 respectively. Decision curve analyses suggested the largest net benefit for KFRE>40% over two years and KFRE>50% over 12 months when it is important to avoid the harm of possibly unnecessary surgery. In Sweden, 54% of nephrology-referred patients started hemodialysis in a central venous catheter (CVC) of which only 5% had AV access surgery >6 months before initiation. 60% of the CVC patients exceeded KFRE>40% a median of 0.8 years (interquartile range 0.4-1.5) before KRT initiation. CONCLUSIONS: The utility of using KFRE>40% and KFRE>50% is higher compared to the more traditionally used eGFR threshold <15 ml/min/1.73m2 for vascular access planning.

Placement of tunneled hemodialysis catheters - interventional standard.

While the native arterio-venous fistula (AVF) remains the first choice in vascular access for most hemodialysis patients, tunneled hemodialysis catheters (tHDC) continue to be an option in selected patients. Since timely access to vascular surgery-due to delayed referral or resource limitations-is not always possible, nephrologists have to become more actively involved in planning, creation and monitoring of vascular access. Moreover, this approach could also strengthen patient-centered care in nephrology. This manuscript reviews the current standard in tHDC creation, patient selection and strategies to mitigate the risk of infectious complications and catheter thrombosis. Presentation of novel developments in catheter placement with ultrasound-guided or ECG-guided positioning, their benefits and possible disadvantages emphasizes the complexity of vascular access planning. We offer an approach for choice of insertion method, depending on selected side and existing resources and set focus on the necessity and required resources of 'interventional nephrology' training programs.

ESR Essentials: arterial vascular access and closure devices-practice recommendations by the Cardiovascular and Interventional Radiological Society of Europe.

Vascular access is the initial, very important, step of endovascular procedures. Various access sites include the common femoral artery, brachial artery, radial artery, popliteal artery, and distal tibial vessels (pedal arteries). Successful arterial access requires advanced knowledge of anatomy, as well as proper training and experience. Today, vascular access should be obtained using real-time, ultrasound guidance to reduce access time, patient discomfort, and puncture-related complications including dissection, arteriovenous communication, and bleeding. Nevertheless, high-level evidence to support this recommendation in peripheral procedures is limited and level A data are mainly derived from randomized cardiac trials investigating only radial and femoral access. Vascular closure devices (VCDs) for femoral access can be broadly categorized as active closure devices, compression assist devices, and external/topical hemostasis devices. There is high-level evidence demonstrating that their use is related to less time for ambulation and increased patient satisfaction. However, available data failed to clearly demonstrate a benefit in complications compared to standard manual compression in peripheral endovascular arterial procedures, and thrombotic and infectious complications reported following VCD use remain an issue. Heterogeneity noted in the literature, caused by the vast variety of devices, access sites, sheath sizes, clinical scenarios, and procedures, poses difficulties in data analysis and future study design. As a result, an individualized VCD use is currently suggested for ≥ 5 Fr femoral artery access not only to reduce time to hemostasis and ambulation and to improve patient comfort, but also to reduce bleeding complications in cases of femoral access with increased bleeding risk, deranged coagulation, and large-bore access, though a high level of evidence to support this later recommendation is limited. KEY POINTS: US guidance is strongly recommended for femoral access and is mandatory to obtain more challenging access. The use of VCDs for femoral hemostasis is generally safe, effective, and currently supported by level I evidence. Proper training and correct VCD choice, based on the patient's individual characteristics, are imperative to optimize outcomes.

Comparing ethanol lock therapy versus vancomycin lock in a salvation strategy for totally implantable vascular access device infections due to coagulase-negative staphylococci (the ETHALOCK study): a prospective double-blind randomized clinical trial.

OBJECTIVES: Little is known about efficacy and safety of ethanol lock therapy (ELT) to treat totally implantable venous access device (TIVAD) infections. The objective of this trial was to evaluate the effectiveness and safety profile of a local treatment with ELT without removal for TIVAD infection due to coagulase-negative staphylococci. METHODS: We performed a prospective, multicenter, double-blind, randomized clinical trial comparing the efficacy of 40% ELT versus vancomycin lock therapy (VLT) in TIVAD infections due to coagulase-negative staphylococci, complicated or not by bloodstream infection. RESULTS: Thirty-one patients were assigned to the ELT group and 30 to the VLT arm. Concomitant bacteremia was present in 41 patients (67.2%). Treatment success was 58.1 % (18 of 31) for the ELT arm and 46.7% (14 of 30) for the VLT arm (p = 0.37). The overall treatment success was 52.5% (32). The risk of treatment failure due to uncontrolled infections, superinfections, and mechanical complications did not differ significantly between participants receiving ELT (13 out of 31 [42%]) and those receiving VLT (16 out of 30 [53%]) with a hazard ratio of 0.70 (p = 0.343; 95% CI [0.34-1.46], Cox model). Catheter malfunctions were significantly more frequent in the ELT arm (11 patients versus 2 in the VLT group, p = 0.01). CONCLUSIONS: We found an overall high rate of treatment failure that did not differ between the ELT arm and the VLT arm. TIVAD removal must be prioritized to prevent complications (uncontrolled infections, superinfections, and catheter malfunctions) except in exceptional situations.

Challenges of Predicting Arteriovenous Access Survival Prior to Conversion from Catheter.

OBJECTIVE: The decision to convert from catheter to arteriovenous access is difficult yet very important. The ability to accurately predict fistula survival prior to surgery would significantly improve the decision making process. Many previously investigated demographic and clinical features have been associated with fistula failure. However, it is not conclusively understood how reliable predictions based on these parameters are at an individual level. The aim of this study was to investigate the probability of arteriovenous fistula maturation and survival after conversion using machine learning workflows. METHODS: A retrospective cohort study on multicentre data from a large North American dialysis organisation was conducted. The study population comprised 73 031 chronic in centre haemodialysis patients. The dataset included 49 variables including demographic and clinical features. Two distinct feature selection and prediction pipelines were used: LASSO regression and Boruta followed by a random forest classifier. Predictions were facilitated for re-conversion to catheter within one year. Additionally, all cause mortality predictions were conducted to serve as a comparator. RESULTS: In total, 38 151 patients (52.2%) had complete data and made up the main cohort. Sensitivity analyses were conducted in 67 421 patients (92.3%) after eliminating variables with a high proportion of missing data points. Selected features diverged between datasets and workflows. A previously failed arteriovenous access appeared to be the most stable predictor for subsequent failure. Prediction of re-conversion based on the demographic and clinical information resulted in an area under the receiver operating characteristic curve (ROCAUC) between 0.541 and 0.571, whereas models predicting all cause mortality performed considerably better (ROCAUC 0.662 - 0.683). CONCLUSION: While group level depiction of major adverse outcomes after catheter to arteriovenous fistula or graft conversion is possible using the included variables, patient level predictions are associated with limited performance. Factors during and after fistula creation as well as biomolecular and genetic biomarkers might be more relevant predictors of fistula survival than baseline clinical conditions.

A Cost-Effective Approach to Resistant AV Fistula Stenosis: Successful Treatment Using Coronary OPN NC® Balloon in a Low-Income Setting.

Stenosis in the anastomotic site or venous limb of an arteriovenous fistula (AVF) is the most frequent cause of AVF failure. Percutaneous angioplasty with a standard or high-pressure balloon is the first-line treatment for AVF stenosis due to its higher technical success rate (90%) and lower complication rate (4%). Almost 20% of stenosis cases are resistant or undilatable by regular-pressure balloon angioplasty due to fibrosis, leading to technical failure or restenosis. Alternative therapies, such as atherectomy devices or cutting balloons, are expensive and difficult to obtain in low-income developing countries. We successfully treated resistant AVF stenosis with a coronary OPN-NC® ultra-high-pressure balloon and produced a good angiographic result with technical success. Coronary hardware is easily available and relatively cheaper compared to dedicated peripheral balloons or devices in our country due to reuse, which can be a boon in such type of cases. According to the standard hospital protocol, Cathlab hardware was reused.

A Prospective Comparison of Standard Technique, Doppler Ultrasonography, and Pressure Waveform Analysis for Confirming Intraosseous Catheter Placement.

Purpose: Intraosseous (IO) catheters allow healthcare workers to rapidly administer fluids and medications to critically ill patients when intravenous access is inadequate or unable to be obtained. An improperly placed IO catheter can lead to delays in care, as well as serious complications such as limb necrosis. Methods: In this single-center, prospective, observational study, we compared 2 established methods of confirming proper IO catheter placement to a novel pressure waveform analysis technique in which the IO catheter is attached to a standard pressure transducer. Attaching a pressure transducer to a properly placed IO catheter produces a pulsatile waveform. Misplacement of the IO catheter produces a flatline waveform. Results: Of 42 IO catheters, 8 (19%) were incorrectly placed per the waveform analysis technique. Compared to the pressure waveform analysis technique, the standard method and the power Doppler method incorrectly classified 4/8 (50%) and 5/8 (62.5%) of the misplaced catheters, respectively. The standard method had a higher positive predictive value for detecting incorrectly placed IO catheters than the power Doppler method (100% vs 63%, respectively). Blinded reviewers demonstrated better agreement using the pressure waveform analysis technique than using power Doppler (k = 0.77 vs k = 0.58, respectively). Conclusion: The standard and power Doppler ultrasonography techniques identify incorrectly placed IO catheters sub-optimally. The pressure waveform analysis technique is more accurate than the standard of care and has superior interrater agreement compared to the ultrasound method of confirmation. With more than 500 000 IO catheters placed in the United States each year, this novel technique may improve overall IO safety. Trial Registration Number: NCT03908879.

Accuracy of Noninvasive Blood Pressure Monitoring in Critically Ill Adults.

Background: Blood pressure (BP) is routinely invasively monitored by an arterial catheter in the intensive care unit (ICU). However, the available data comparing the accuracy of noninvasive methods to arterial catheters for measuring BP in the ICU are limited by small numbers and diverse methodologies. Purpose: To determine agreement between invasive arterial blood pressure monitoring (IABP) and noninvasive blood pressure (NIBP) in critically ill patients. Methods: This was a single center, observational study of critical ill adults in a tertiary care facility evaluating agreement (≤10% difference) between simultaneously measured IABP and NIBP. We measured clinical features at time of BP measurement inclusive of patient demographics, laboratory data, severity of illness, specific interventions (mechanical ventilation and dialysis), and vasopressor dose to identify particular clinical scenarios in which measurement agreement is more or less likely. Results: Of the 1852 critically ill adults with simultaneous IABP and NIBP readings, there was a median difference of 6 mm Hg in mean arterial pressure (MAP), interquartile range (1-12), P < .01. A logistic regression analysis identified 5 independent predictors of measurement discrepancy: increasing doses of norepinephrine (adjusted odds ratio [aOR] 1.10 [95% confidence interval, CI 1.08-1.12] P = .03 for every change in 5 µg/min), lower MAP value (aOR 0.98 [0.98-0.99] P < .01 for every change in 1 mm Hg), higher body mass index (aOR 1.04 [1.01-1.09] P = .01 for an increase in 1), increased patient age (aOR 1.31 [1.30-1.37] P < .01 for every 10 years), and radial arterial line location (aOR 1.74 [1.16-2.47] P = .04). Conclusions: There was broad agreement between IABP and NIBP in critically ill patients over a range of BPs and severity of illness. Several variables are associated with measurement discrepancy; however, their predictive capacity is modest. This may guide future study into which patients may specifically benefit from an arterial catheter.

POCUS in the PICU: A Narrative Review of Evidence-Based Bedside Ultrasound Techniques Ready for Prime-Time in Pediatric Critical Care.

Point-of-care ultrasound (POCUS) is an accessible technology that can identify and treat life-threatening pathology in real time without exposing children to ionizing radiation. We aim to review current evidence supporting the use of POCUS by pediatric intensivists with novice-level experience with bedside ultrasound. Current evidence supports the universal adoption of POCUS-guided internal jugular venous catheter placement and arterial line placement by pediatric critical care physicians. Focused cardiac ultrasound performed by PICU physicians who have completed appropriate training with quality assurance measures in place can identify life-threatening cardiac pathology in most children and important physiological changes in children with septic shock. POCUS of the lungs, pleural space, and diaphragm have great potential to provide valuable information at the bedside after validation of these techniques for use in the PICU with additional research. Based on currently available evidence, a generalizable and attainable POCUS educational platform for pediatric intensivists should include training in vascular access techniques and focused cardiac examination. A POCUS educational program should strive to establish credentialing and quality assurance programs that can be expanded when additional research validates the adoption of additional POCUS techniques by pediatric intensive care physicians.