Technique for minimizing and treating driveline infections

Short-term Retention of Patient and Caregiver Ventricular Assist Device Self-care Skills after Simulation-based Mastery Learning

Background

We developed a simulation-based mastery learning (SBML) curriculum that boosted self-care skills for patients with a ventricular assist device (VAD). In this study, we evaluated short-term skills retention.

Methods

We assessed skill retention among patients and caregivers who participated in VAD self-care SBML at a tertiary care center. We compared discharge skills tests (immediately after completing SBML) to 1- and 3-month follow-up tests to assess skill retention.

Results

Fifteen patients and 15 caregivers completed discharge and follow-up testing. Skills were largely retained at 1- and 3-months.

Conclusions

SBML results in short-term retention of VAD self-care skills.

Epidemiology of Left Ventricular Assist Device Infections: Findings From a Large Nonregistry Cohort

BACKGROUND

Infection is a major complication during circulatory support with a left ventricular assist device (VAD). Changes in device characteristics and treatment practices in the last decade can affect the epidemiology of infection. The International Society for Heart and Lung Transplantation (ISHLT) has published recommendations on the prevention and management of VAD infections, but data to support these recommendations remain sparse.

METHODS

We performed a retrospective review of 455 patients who underwent VAD placement from 2009 to 2015. Infection episodes were defined using ISHLT criteria and were also grouped as endovascular or local. Analysis included descriptive statistics.

RESULTS

There were 174 patients (38.6%) with a VAD infection. Infection incidence was 36.9 cases per 100 person-years of VAD support. The driveline was the most common infection site (67.2%). Systemic inflammatory response syndrome (SIRS) criteria were not satisfied in 29.2% of patients with endovascular infections, and computed tomography (CT) examinations were normal in 37.7% of cases. Gram-positive bacteria caused 65.6% of infections in patients with an available culture. Antimicrobial suppression was used in 72.3% of patients who survived treatment. Median survival after infection was 35 months for patients with VAD-related infections versus 14 months for patients with VAD-specific infections.

CONCLUSIONS

VAD infections continue to be a major complication after implantation. Clinical criteria alone were not predictive of serious infections, and many patients with confirmed infection had normal CTs. Patients with VAD-specific infections had lower median survival than patients with VAD-related infections.

Ventricular Assist Device-Specific Infections

Ventricular assist device (VAD)-specific infections, in particular, driveline infections, are a concerning complication of VAD implantation that often results in significant morbidity and even mortality. The presence of a percutaneous driveline at the skin exit-site and in the subcutaneous tunnel allows biofilm formation and migration by many bacterial and fungal pathogens. Biofilm formation is an important microbial strategy, providing a shield against antimicrobial treatment and human immune responses; biofilm migration facilitates the extension of infection to deeper tissues such as the pump pocket and the bloodstream. Despite the introduction of multiple preventative strategies, driveline infections still occur with a high prevalence of ~10-20% per year and their treatment outcomes are frequently unsatisfactory. Clinical diagnosis, prevention and management of driveline infections are being targeted to specific microbial pathogens grown as biofilms at the driveline exit-site or in the driveline tunnel. The purpose of this review is to improve the understanding of VAD-specific infections, from basic "bench" knowledge to clinical "bedside" experience, with a specific focus on the role of biofilms in driveline infections.

Simulation-Based Mastery Learning Improves Patient and Caregiver Ventricular Assist Device Self-Care Skills: A Randomized Pilot Trial

BACKGROUND

No recognized standards exist for teaching patients and their caregivers ventricular assist device (VAD) self-care skills. We compared the effectiveness of a VAD simulation-based mastery learning (SBML) self-care training curriculum with usual VAD self-care training.

METHODS AND RESULTS

VAD patients and their caregivers were randomized to SBML or usual training during their implant hospitalization. The SBML group completed a pretest on 3 VAD self-care skills (controller, power source, and dressing change), then viewed videos and participated in deliberate practice on a simulator. SBML participants took a posttest and were required to meet or exceed a minimum passing standard for each of the skills. The usual training group completed the existing institutional VAD self-care teaching protocol. Before hospital discharge, the SBML and usual training groups took the same 3 VAD self-care skills tests. We compared demographic and clinical information, self-confidence, total participant training time, and skills performance between groups. Forty participants completed the study in each group. There were no differences in demographic and clinical information, self-confidence, or training time between groups. More participants in the SBML group met the minimum passing standard compared with the usual training group for controller (37/40 [93%] versus 25/40 [63%]; P=0.001), power source (36/40 [90%] versus 9/40 [23%]; P<0.001), and dressing change skills (19/20 [95%] versus 0/20; P<0.001).

CONCLUSIONS

SBML provided superior VAD self-care skills learning outcomes compared with usual training. This study has important implications for patients due to the morbidity and mortality associated with improper VAD self-care.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT03073005.

Role of imaging in diagnosis and management of left ventricular assist device complications

Heart failure is a clinical condition that is associated with significant morbidity and mortality. With the advent of left ventricular assist device (LVAD), an increasing number of patients have received an artificial heart both as a bridge-to-therapy and as a destination therapy. Clinical trials have shown clear survival benefits of LVAD implantation. However, the increased survival benefits and improved quality of life come at the expense of an increased complication rate. Common complications include perioperative bleeding, infection, device thrombosis, gastrointestinal bleeding, right heart failure, and aortic hemodynamic changes. The LVAD-associated complications have unique pathophysiology. Multiple imaging modalities can be employed to investigate the complications, including computed tomography (CT), positron emission tomography-computed tomography (PET-CT), catheter angiography and echocardiography. Imaging studies not only help ascertain diagnosis and evaluate the severity of disease, but also help direct relevant clinical management and predict prognosis. In this article, we aim to review the common LVAD complications, present the associated imaging features and discuss the role of imaging in their management.

The Effect of Judge Selection on Standard Setting Using the Mastery Angoff Method during Development of a Ventricular Assist Device Self-Care Curriculum

Background

Patients and caregivers need to perform ventricular assist device (VAD) self-care safely to help prevent complications (e.g., infection). We developed a VAD self-care simulation-based mastery learning (SBML) curriculum. We determined optimal minimum passing scores (MPSs) and evaluated effects of judge selection.

Methods

A multidisciplinary team created a VAD self-care SBML curriculum including simulated skills and knowledge examinations. Patients, caregivers, VAD coordinators, and physicians were expert judges who determined MPSs using the Mastery Angoff method.

Results

MPSs for the skills and knowledge examinations were high (range = 94-99% and 97% correct), respectively. Judges closely agreed on MPSs.

Conclusions

Stakeholders set stringent MPSs for high-stakes VAD self-care.

The momentum of HeartMate 3: a novel active magnetically levitated centrifugal left ventricular assist device (LVAD)

Left ventricular assist devices (LVADs) are emerging as the treatment of choice for advanced heart failure due to the dearth of healthy donor hearts for cardiac transplantation. The HeartMate 3 LVAD is a novel centrifugal pump which was developed to provide hemodynamic support in heart failure patients, either as a bridge to transplant (BTT), myocardial recovery, or as destination therapy (DT). Technological and clinical advancements have led to optimized hemocompatibility and development of less invasive surgical procedures for the implantation of this pump. The worldwide first implantation of the HeartMate 3 was performed by Prof. Schmitto and his team at Hannover Medical School, Germany in 2014, paving the way for subsequent surgical developments. This article summarizes the advanced technological and clinical aspects of the HeartMate 3 and outlines future technical developments for safe and effective treatment of advanced heart failure.

Wound care of the driveline exit site in patients with a ventricular assist device: A systematic review

BACKGROUND

This study aims to systematically define and analyze the studies on driveline exit site care methods for patients with a ventricular assist device.

METHODS

The studies related to driveline exit site care of the patients with a ventricular assist device published in English and Turkish between 2008 and 2017 were reviewed from the international Science Direct, PubMed, Web of Science, Scopus, and the national databases. Of a total of 83 articles, a total of seven research articles which met the inclusion criteria were included in the study.

RESULTS

Findings related to the agents used in the cleaning of the driveline exit site, dressing closures, dressing change frequency, and use of driveline anchoring devices were obtained from studies included in the research. It was found that chlorhexidine solution for skin cleaning and sterile gauze sheets and transparent covering for dressing closure were the most preferred methods for the driveline exit site care. Dressing change frequency varied considerably from center to center and anchoring devices were used in all studies.

CONCLUSION

There is no gold standard method for the driveline exit site care of patients with a ventricular assist device and researches on the driveline exit site care seem to be limited. It is recommended that large-scale, randomized-controlled studies should be conducted which would provide a stronger proof of the driveline exit site care.

The Role of Computed Tomography in Predicting Left Ventricular Assist Device Infectious Complications

Objective:

The purpose of this study is to identify early computed tomography findings around the driveline which would predict mediastinal or left ventricular assist device (LVAD) pocket abscess formation.

Materials and Methods:

A retrospective analysis was performed on 128 LVAD recipients between January 2007 and December 2011. Infectious complications were subdivided into those affecting the driveline and those resulting in abscess formation either around the LVAD pump or mediastinum. The size and location of infiltrative changes surrounding the driveline were used to predict infection propagation resulting in abscess.

Results:

Of the 128 patients, 49 (38.3%) patients developed driveline infections and 24 (18.8%) patients developed abscess. 87.5% patients who developed abscess had a preceding driveline infection. The mean time from driveline infection to the development of pump pocket abscess was approximately 7 months. In addition, patients with abscess in the pump pocket or mediastinum had preceding infiltrative changes surrounding the driveline ≥14 mm (P = 0.0001). A preperitoneal location and size of infiltrative changes ≥14 mm were correlated with a higher likelihood of abscess formation (P = 0.0002).

Conclusion:

Our study demonstrates the predictive value of infection/infiltrative changes around the driveline, which increases the risk for abscess formation in the LVAD pump pocket and/or in the mediastinum.

Correlation between driveline features and driveline infection in left ventricular assist device selection

Although the survival rate for left ventricular assist device (LVAD) therapy has improved, device-related complications are an unpredictable threat to the patient's quality of life. We focused on driveline infection, and aimed to determine whether specific features of drivelines affect the frequency of infection. We enrolled patients who underwent LVAD implantation and were followed-up at our institute between 2007 and 2015. We counted the occurrences of driveline infection requiring any antibiotic therapy over a 2-year study period. Furthermore, we experimentally measured and compared the outer diameters and stiffness of three devices. Of all, 72 patients received an LVAD during the enrollment period. LVADs were HeartMate II (n = 32), EVAHEART (n = 22), and DuraHeart (n = 18). The outer diameters and stiffness were measured in five of each device. HeartMate II group had the highest driveline infection-free rate among all three devices during the study period (p = 0.042). The driveline of the HeartMate II LVAD had a significantly smaller outer diameter and lower stiffness than that of the other two devices (p < 0.05 for both). In conclusion, device-specific driveline features may affect the development of driveline infection during LVAD therapy.

Mechanical Circulatory Support and the Role of LVADs in Heart Failure Therapy

Heart failure is epidemic in the United States with a prevalence of over 5 million. The diagnosis carries a mortality risk of 50% at 5 years rivaling many diagnoses of cancer. Heart transplantation, long the “gold standard” treatment for end stage heart failure unresponsive to maximal medical therapy falls way short of meeting the need with only about 2,000 transplants performed annually in the United States due to donor limitation. Left ventricular devices have emerged as a viable option for patients as both a “bridge to transplantation” and as a final “destination therapy”.