Bloodstream infections in prolonged use of axillary-placed, intra-aortic balloon-pump support: A single-center study

Infections from prolonged use of axillary intra-aortic balloon pumps (IABPs) have not been well studied. Bloodstream infection (BSI) occurred in 13% of our patients; however, no difference in outcome was noted between those with BSI and those without. Further studies regarding protocol developments that minimize BSI risk are needed.

Vancomycin dosing in high-intensity continuous renal replacement therapy: A retrospective cohort study

INTRODUCTION

An inverse relationship exists between vancomycin serum concentrations and the intensity of continuous renal replacement therapy (CRRT), reflected through the dialysate flow rate (DFR). There remains a lack of evidence to guide initial vancomycin dosing in the setting of high-intensity CRRT (i.e., DFR >30 mL/kg/h). Additionally, recommendations for pharmacokinetic monitoring of vancomycin have transitioned from a trough-based to area under the curve (AUC)-based dosing strategy to optimize efficacy and safety. Therefore, an improved understanding of the impact of CRRT intensity on AUC/MIC (minimum inhibitory concentration) has the potential to enhance vancomycin dosing in this patient population.

OBJECTIVES

The goal of this study is to evaluate current vancomycin dosing strategies and achievement of pharmacokinetic targets in patients on high-intensity CRRT.

METHODS

This was a single-center, retrospective cohort study of adult critically ill patients admitted to Houston Methodist Hospital between May 2019 and October 2021 and received vancomycin therapy while on high-intensity CRRT. High-intensity CRRT was defined by a DFR that was both ≥3 L/h and >30 mL/kg/h. Depending on the initial vancomycin dosing strategy, patients were stratified into either the traditional (15 mg/kg/day) or enhanced (≥15 mg/kg/day) dosing group. The primary outcome was the percent of patients who attained steady-state AUC24 /MIC ≥400 mg*h/L at the first obtained vancomycin level in the enhanced group compared with the traditional group.

RESULTS

A total of 125 patients were included in the final analysis, 56 in the traditional and 69 in the enhanced dosing group. The primary end point occurred in 74% and 54% of patients in the enhanced and traditional dosing groups, respectively (p = 0.029). Therapeutic vancomycin trough levels (10-20 μg/mL) were more commonly achieved in the enhanced dosing group compared with the traditional dosing group (66.7% vs. 45%, p = 0.013). As DFR rose, increasingly higher doses of vancomycin, up to 27 mg/kg/day, were required to achieve the therapeutic targets.

CONCLUSION

This is the first study to evaluate the influence of variable CRRT intensities on vancomycin AUC/MIC. Our findings suggest that vancomycin doses of ≥15 mg/kg/day are needed to achieve early therapeutic targets in patients on high-intensity CRRT.

2013. Bloodstream Infections in Advanced Heart Failure Patients Requiring Prolonged Use of Axillary Intra-Aortic Balloon Pumps - A Single Center Study

Background

Bloodstream infections (BSI) impact outcomes in critically ill patients. Institutions and quality and performance improvement efforts to minimize catheter associated infections are valued to optimize outcomes. While intra-aortic balloon pumps (IABP) implanted through the axillary route have been recently used in cardiogenic shock patients for prolonged support, the incidence and associated significance of BSI remains unknown in this cohort. The aim of this study was to assess the incidence of BSI in patients with axillary-placed IABP and evaluate its impact on patient outcomes.

Methods

We retrospectively reviewed 141 patients that underwent axillary IABP placement from May 2016 through August 2020. The primary endpoint was the incidence of BSI during axillary IABP, reported as the proportion of patients who developed a BSI and BSI per 1000-device days.

Results

BSI occurred in 13% of patients and accounted for 4.3 infections per 1000-device days. Prior femoral device use and longer duration of axillary IABP support occurred more frequently in the BSI cohort. Presence of traditional BSI risk factors including central line days, use of parenteral nutrition, and prior positive cultures did not differ between those who developed BSI and those who did not. The rate of end-outcome attainment (transplant, LVAD, recovery) was not statistically different in those that developed BSI vs not (72% vs 88% p=0.08). A total of 41% of BSI were caused by Staphylococcus epidermidis. Use of peri-procedural antimicrobials was associated with lower risk of BSI development (24% vs 8%; p=0.01)

Conclusion

Patients in cardiogenic shock requiring use of life-saving temporary mechanical support pose a challenge to maintain free of BSI during prolonged support with an indwelling catheter that allows for ambulation and movement. Mitigation of modifiable BSI risk factors, such as the use of peri-procedural antimicrobial prophylaxis, accompanied by a low threshold for screening and treatment are reasonable strategies to improve patient outcomes. Future research is needed to further evaluate BSI risk in this patient population and its subsequent impact on patient outcomes.

Disclosures

All Authors: No reported disclosures.

Perioperative cangrelor in patients with recent percutaneous coronary intervention undergoing liver transplantation: A case series

BACKGROUND

Management of dual antiplatelet therapy (DAPT) in the perioperative setting is challenging, particularly in complex patient populations, such as those with underlying coagulopathy and/or recent percutaneous coronary interventions.

METHODS

In this case series, we describe the perioperative use of cangrelor bridge therapy in two patients undergoing liver transplantation after recent coronary drug-eluting stent placement.

OUTCOMES

In both patient cases, cangrelor use as a P2Y12 bridge at a dose of 0.75 μg/kg/min was safe and effective. Both patients were successfully switched back to their oral DAPT regimen post-operatively without additive bleeding or thrombotic complications.

CONCLUSION

The use of cangrelor as bridge therapy in high-risk perioperative liver transplant patients appears to be a viable option when DAPT is warranted.

Evaluation of Inhaled Alprostadil in Hospitalized Adult Patients

BACKGROUND

Intermittent inhaled alprostadil (iPGE₁) may be a viable alternative to inhaled nitric oxide or epoprostenol for management of right ventricular failure, pulmonary hypertension (pHTN) or acute respiratory distress syndrome (ARDS). However, limited evidence exists regarding iPGE₁ use in adults, ideal dosing strategies, or optimal use cases.

OBJECTIVE

To describe the clinical characteristics of patients receiving iPGE₁ and identify specific sub-populations warranting further research.

METHODS

This was a single-center, retrospective, descriptive analysis of inpatients who received at least one dose of iPGE₁. The primary outcome was to describe patient characteristics and alprostadil dosing strategies. Secondary outcomes included changes in respiratory support requirements, hemodynamics, and inotropic/vasoactive use. Outcomes were stratified and compared based on primary therapeutic indication (cardiac or pulmonary).

RESULTS

Fifty-four patients received iPGE₁ 40 (75%) for pulmonary (pHTN or ARDS) and 14 (25%) for cardiac indications. There was no difference between indications in the number of patients de-escalated from level of respiratory (53% vs 57%, P = 0.76), inotropic (70% vs 57%, P = 0.39), or vasopressor support (78% vs 57%, P = 0.17). Furthermore, there was no significant improvement in cardiopulmonary parameters at multiple time intervals after iPGE₁ initiation.

CONCLUSION AND RELEVANCE

This is the largest study to date on the use of intermittent iPGE₁ in adults. Alprostadil was safely utilized in novel populations; however, efficacy as evaluated by clinical or surrogate endpoints could not be demonstrated and further investigation is needed to determine its potential and optimal place in therapy.

Direct Oral to Parenteral Anticoagulants: Strategies for Inpatient Transition

The primary objective of this study was to describe the impact on bleeding rates of 2 different strategies for transitioning from a direct oral anticoagulant (DOAC) to a parenteral anticoagulant: a delayed, clinically driven strategy versus the standard per-package-insert strategy. This was a single-center descriptive cohort study conducted at a large academic medical center. Included patients were 18 years or older, admitted as an inpatient, and had received at least 1 dose of a DOAC prior to initiation of therapeutic parenteral anticoagulation. The primary end point was the incidence of major bleeds on the transition from a DOAC to a parenteral anticoagulant via a standard versus an intentionally delayed strategy. The secondary outcomes evaluated renal function, reason for delay, DOAC anti-factor Xa concentration, international normalized ratio values, blood product administration, and thrombotic complications. A total of 300 patients were included. The primary end point of bleeding was higher in the delayed group than the standard group, 25% and 12%, respectively (odds ratio, 0.39; P < .05). In both groups, patients who bled had a higher severity of illness, a greater incidence of acute kidney injury, and, when available, higher median DOAC anti-factor Xa concentrations. Despite a more conservative approach, patients in the delayed group experienced more bleeding, most likely attributable to a higher severity of illness, which highlights emerging challenges of inpatient anticoagulation management. Further prospective studies analyzing DOAC pharmacodynamics and pharmacokinetics in acutely ill patients are warranted.

Management of Anticoagulation with Impella® Percutaneous Ventricular Assist Devices and Review of New Literature

Cardiogenic shock is a life-threatening condition that may occur secondary to a variety of cardiac conditions, and may require temporary support with percutaneous ventricular devices like the Impella®. Anticoagulation in patients with Impella® devices can often be complicated due to unpredictable purge flow rates, pre-existing coagulopathy, or heparin allergies. The purpose of this article is to discuss the various options for anticoagulation in the setting of Impella®. The article will also describe recent updates (2014-current) in literature surrounding anticoagulation therapy for Impella® devices. At total of 228 articles were initially obtained through the PubMed search, with inclusion of 6 articles. A total of 51 patients had data in the six studies that were included in the review. Heparin for anticoagulation in the purge solution, at two different dextrose concentrations (5% and 20%), was associated with similar therapeutic activated partial thromboplastin time rates, thrombotic and bleeding events. One case series described the use of argatroban in the purge solution for anticoagulation in two patients with suspected heparin-induced thrombocytopenia, without bleeding or thrombotic complications. Pump thrombosis was not reported in any of the six studies. Anticoagulation in the setting of mechanical circulatory support devices is a challenging aspect of critical care. Institutions should have set protocols that clearly define the options for anticoagulation. Future studies that look at longer durations of support and possible operation of the Impella® device with a heparin-free purge solution are needed.