Cardiac Substrate Utilization and Relationship to Invasive Exercise Hemodynamic Parameters in HFpEF.

The authors conducted transcardiac blood sampling in healthy subjects and subjects with heart failure with preserved ejection fraction (HFpEF) to compare cardiac metabolite and lipid substrate use. We demonstrate that fatty acids are less used by HFpEF hearts and that lipid extraction is influenced by hemodynamic factors including pulmonary pressures and cardiac index. The release of many products of protein catabolism is apparent in HFpEF compared to healthy myocardium. In subgroup analyses, differences in energy substrate use between female and male hearts were identified.

Tropoelastin Improves Post-Infarct Cardiac Function.

BACKGROUND: Myocardial infarction (MI) is among the leading causes of death worldwide. Following MI, necrotic cardiomyocytes are replaced by a stiff collagen-rich scar. Compared to collagen, the extracellular matrix protein elastin has high elasticity and may have more favorable properties within the cardiac scar. We sought to improve post-MI healing by introducing tropoelastin, the soluble subunit of elastin, to alter scar mechanics early after MI. METHODS AND RESULTS: We developed an ultrasound-guided direct intramyocardial injection method to administer tropoelastin directly into the left ventricular anterior wall of rats subjected to induced MI. Experimental groups included shams and infarcted rats injected with either PBS vehicle control or tropoelastin. Compared to vehicle treated controls, echocardiography assessments showed tropoelastin significantly improved left ventricular ejection fraction (64.7±4.4% versus 46.0±3.1% control) and reduced left ventricular dyssynchrony (11.4±3.5 ms versus 31.1±5.8 ms control) 28 days post-MI. Additionally, tropoelastin reduced post-MI scar size (8.9±1.5% versus 20.9±2.7% control) and increased scar elastin (22±5.8% versus 6.2±1.5% control) as determined by histological assessments. RNA sequencing (RNAseq) analyses of rat infarcts showed that tropoelastin injection increased genes associated with elastic fiber formation 7 days post-MI and reduced genes associated with immune response 11 days post-MI. To show translational relevance, we performed immunohistochemical analyses on human ischemic heart disease cardiac samples and showed an increase in tropoelastin within fibrotic areas. Using RNA-seq we also demonstrated the tropoelastin gene ELN is upregulated in human ischemic heart disease and during human cardiac fibroblast-myofibroblast differentiation. Furthermore, we showed by immunocytochemistry that human cardiac fibroblast synthesize increased elastin in direct response to tropoelastin treatment. CONCLUSIONS: We demonstrate for the first time that purified human tropoelastin can significantly repair the infarcted heart in a rodent model of MI and that human cardiac fibroblast synthesize elastin. Since human cardiac fibroblasts are primarily responsible for post-MI scar synthesis, our findings suggest exciting future clinical translation options designed to therapeutically manipulate this synthesis.

Patient blood management in critically ill children undergoing cardiac surgery: A cohort study.

OBJECTIVE: The objective of this study was to audit current patient blood management practice in children throughout cardiac surgery and paediatric intensive care unit (PICU) admission. DESIGN: This was a prospective observational cohort study. SETTING: This was a single-centre study in the cardiac operating room (OR) and PICU in a major tertiary children's hospital in Australia. PATIENTS: Children undergoing corrective cardiac surgery and requiring admission to PICU for postoperative recovery were included in the study. MEASUREMENTS AND MAIN RESULTS: Fifty-six patients and 1779 blood sampling episodes were audited over a 7-month period. The median age was 9 months (interquartile range [IQR] = 1-102), with the majority (n = 30 [54%]) younger than 12 months. The median number of blood sampling episodes per patient per day was 6.6 (IQR = 5.8-8.0) in total, with a median of 5.0 (IQR = 4.0-7.5) episodes in the OR and 5.0 (IQR = 3.4-6.2) episodes per day throughout PICU admission. The most common reason for blood tests across both OR and PICU settings was arterial blood gas analysis (total median = 86%, IQR = 79-96). The overall median blood sampling volume per kg of bodyweight, patient, and day was 0.63 mL (IQR = 0.20-1.14) in total. Median blood loss for each patient was 3.5 mL/kg per patient per day (IQR = 1.7-5.6) with negligible amounts in the OR and a median of 3.6 mL/kg (IQR = 1.7-5.7) in the PICU. The median Cell Saver® transfusion volume was 9.9 mL/kg per patient per day (IQR = 4.0-19.1) in the OR. The overall median volume of other infusion products (albumin 4%, albumin 20%, packed red blood cells) received by each patient was 20.1 mL/kg (IQR = 10.7-36.4) per day. Sampling events and blood loss were positively associated with PICU stay. CONCLUSIONS: Patient blood management practices observed in this study largely conform to National Blood Authority guidelines. Further implementation projects and research are needed to accelerate implementation of known effective blood conservation strategies within paediatric critical care environments.

Review article: Peripheral intravenous catheter insertion in adult patients with difficult intravenous access: A systematic review of assessment instruments, clinical practice guidelines and escalation pathways.

The optimal approach for peripheral intravenous catheter (PIVC) insertion in adult hospitalised patients with difficult intravenous access (DIVA) is unknown. The present study aimed to critically appraise the quality of (i) assessment instruments and (ii) clinical practice guidelines (CPGs) or escalation pathways for identifying and managing patients with DIVA. Cochrane Central Register of Controlled Trials, EBSCO MEDLINE, EMBASE (OVID) and EBSCO CINAHL databases were searched on 22 March 2021. Studies describing a DIVA assessment measure, CPG or escalation pathway for PIVC insertion in adults (≥18 years of age) were included. Data were extracted using a standardised data extraction form including study design, type of resource and reported clinical outcomes. Quality of DIVA assessment instruments were reviewed using the COnsensus-based Standards for the selection of health Measurement Instruments checklist. Methodological quality of CPGs and escalation pathways was assessed using the Appraisal of Guidelines for Research and Evaluation-II (AGREE-II) instrument. Overall, 24 DIVA resources comprising 16 DIVA assessment instruments and nine CPGs or escalation pathways (including one combined assessment instrument and escalation pathway) were identified. Instruments commonly focused on vein visibility and palpability as indicators of DIVA. CPGs and escalation pathways unanimously recommended use of vessel visualisation technology for patients with or suspected of DIVA. Methodological quality of the resources was mixed. Consensus and standardisation of resources to identify DIVA and recommendations for managing patients with DIVA is limited. Adopting consistent, evidence-based CPGs, escalation pathways or DIVA assessment instruments may significantly improve clinical outcomes.

Peripheral intravenous catheter insertion and use of ultrasound in patients with difficult intravenous access: Australian patient and practitioner perspectives to inform future implementation strategies.

OBJECTIVE: To understand healthcare worker and patient experience with peripheral intravenous catheter (PIVC) insertion in patients with difficult intravenous access (DIVA) including the use of ultrasound (US). METHODS: Descriptive study using 1-on-1 semi-structured interviews conducted between August 2020 and January 2021. Purposeful sampling was used to recruit healthcare practitioners (HCPs) and patients with DIVA who had PIVC experience. Data were analysed using inductive thematic analysis. Interview data were than mapped to the implementation theory Behaviour Change Wheel to inform implementation strategies. RESULTS: In total 78 interviews (13 patients; 65 HCPs) were completed with respondents from metropolitan (60%), regional (25%) and rural/remote (15%) settings across Australia. Thematic analysis revealed 4 major themes: i) Harmful patient experiences persist, with patient insights not leveraged to effect change; ii) 'Escalation' is just a word on the front lines; iii) Heightened risk of insertion failure without resources and training; and iv) Paving the way forward-'measures need to be in place to prevent failed insertion attempts. Themes were mapped to the behaviour change wheel and implementation strategies developed, these included: staff education, e-health record for DIVA identification, DIVA standard of care and DIVA guidelines to support escalation and ultrasound use. CONCLUSION(S): DIVA patients continue to have poor healthcare experiences with PIVC insertion. There is poor standardisation of DIVA assessment, escalation, US use and clinician education across hospitals. Quality, safety, and education improvement opportunities exist to improve the patient with DIVA experience and prevent traumatic insertions. We identified a number of implementation strategies to support future ultrasound and DIVA pathway implementation.

Forearmed is forewarned: A prospective intervention observational time-series study of patient empowerment for ultrasound-guided peripheral intravenous access.

OBJECTIVE: Ultrasound (US) is a valuable adjunct to improve the success rates of difficult peripheral intravenous cannula (PIVC) insertions but is usually clinician initiated. The present study assessed for any change in clinician practice resulting from interventions aimed at empowering patients to advocate for early use of US if they self-identified as having difficult PIVC access. METHODS: This was a prospective observational time-series study using a rapid quality improvement (RQI) framework. Three ED waiting room intervention strategies (printed media, video and wristband) were tested over three 2-week periods at a large teaching hospital. The impact of each intervention was assessed at eight time points during each intervention and compared to a pre-intervention baseline period using trend and time-series analysis. RESULTS: A total of 1611 PIVC insertions were surveyed over 42 time points. The proportion of US-guided PIVC insertions was highest during Intervention 3 (wristbands; 5.5%) but all proportions remained below baseline (6.5%). Trend analysis identified an increasing frequency of US use during Intervention 1 (printed media, P = 0.01). However, no statistically significant trends were observed within the periods. CONCLUSIONS: This is the first prospective study to assess the effect of various interventions to empower patients to self-identify as having difficult PIVC access and advocate for the use of US-guidance. The present study was indeterminate: no intervention tested in the present study noticeably influenced clinical practice, potentially attributable to the study design and confounding factors. This innovative study serves as a pilot for future research into patient empowerment, which is currently lacking in the literature.

Evaluating the Impact of Central Venous Catheter Materials and Design on Thrombosis: A Systematic Review and Meta-Analysis.

BACKGROUND: Thrombosis is a common complication associated with central venous catheter (CVC) insertion. Several antithrombogenic materials and alterations to catheter design have been developed to lower thrombosis rates. AIM: To systematically evaluate the effectiveness and safety of antithrombogenic materials and alterations to CVC design on thrombosis rates. METHODS: A systematic search was completed of main databases (CINAHL, EMBASE, MEDLINE, and PubMed) as well as trial registries and gray literature. Randomized controlled trials conducted in any age group, published in English language since 2008 reporting impact of different CVC designs or materials on thrombosis were included, to capture studies that reflect contemporary products and practice. Cochrane systematic review methodology was followed, including independent study selection and data extraction. Quality appraisal was conducted using the Cochrane risk of bias tool. A narrative synthesis and meta-analysis in RevMan were conducted. RESULTS: From a possible 232 studies, nine studies met the inclusion criteria. Four studies (n = 1,320) assessed different catheter materials; four studies (n = 591) compared different CVC designs, and one study (n = 150) evaluated impact of combined design and material on outcomes. Meta-analysis demonstrated that neither catheter material nor design alone or in combination had a significant impact on thrombosis (RR: 0.98 [95% CI 0.87, 1.11]). Different catheter materials and design also had no significant impact on occlusion or CRBSI. Studies were of mixed quality overall. LINKING EVIDENCE TO ACTION: Different CVC materials and designs were not associated with a reduction in the risk of either catheter-related thrombosis or infection. Overall reporting and small sample sizes make it difficult to draw firm conclusions. Larger, quality randomized trials are required to provide evidence about the possible merits of innovative catheter design and materials on patient outcomes.