Impact of Invasive Fungal Diseases on Survival under Veno-Venous Extracorporeal Membrane Oxygenation for ARDS

Prevalence and prognostic relevance of invasive fungal disease during veno-arterial ECMO: A retrospective single-center study

PURPOSE

To assess the prevalence and relevance of invasive fungal disease (IFD) during veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective analysis from January 2013 to November 2023 of adult V-A ECMO cases at a German University Hospital. Parameters relating to IFD, demographics, length of stay (LoS), days on ECMO and mechanical ventilation, prognostic scores and survival were assessed. Multivariable logistic regression analyses with IFD and death as dependent variables were performed. Outcome was assessed after propensity score matching IFD-patients to non-IFD-controls.

RESULTS

421 patients received V-A ECMO. 392 patients with full electronic datasets were included. The prevalence of IFD, invasive candidiasis and probable invasive pulmonary aspergillosis was 4.6%, 3.8% and 1.0%. Severity of acute disease, pre-existing moderate-to-severe renal disease and continuous kidney replacement therapy were predictive of IFD. In-hospital mortality (94% (17/18) compared to 67% (252/374) in non-IFD patients (p = 0.0156)) was predicted by female sex, SOFA score at admission, SAVE score and IFD (for IFD: OR: 8.31; CI: 1.60-153.18; p: 0.044). There was no difference in outcome after matching IFD-cases to non-IFD-controls.

CONCLUSIONS

IFD are detected in about one in 20 patients on V-A ECMO, indicating mortality >90%. However, IFD do not contribute to prognosis in this population.

Infectious diseases and infection control prevention strategies in adult and pediatric population on ECMO

As survival after ECMO improves and use of ECMO support increases in both pediatric and adult population, there is a need to focus on both the morbidities and complications associated with ECMO and how to manage and prevent them. Infectious complications during ECMO often have a significant clinical impact, resulting in increased morbidity or mortality irrespective of the underlying etiology necessitating cardiorespiratory support. In this review article, we discuss the prevention, management, challenges, and differences of infectious complications in adult and pediatric patients receiving ECMO support.

Antifungals in Patients With Extracorporeal Membrane Oxygenation: Clinical Implications

Extracorporeal membrane oxygenation (ECMO) is a life-saving technique used in critical care medicine for patients with severe respiratory or cardiac failure. This review examines the treatment and prophylaxis of fungal infections in ECMO patients, proposing specific regimens based on available data for different antifungals (azoles, echinocandins, amphotericin B/liposomal amphotericin B) and invasive fungal infections. Currently, isavuconazole and posaconazole have the most supported data, while modified dosages of isavuconazole are recommended in ECMO. Echinocandins are preferred for invasive candidiasis. However, choosing echinocandins is challenging due to limited and varied data on concentration loss in the ECMO circuit. Caution is likewise advised when using liposomal amphotericin B due to uncertain concentrations and potential ECMO dysfunction based on scarce data. We further conclude with the importance of further research on the impact of ECMO on antifungal drug concentrations to optimize dosing regimens in critically ill patients.

The impact of extracorporeal membrane oxygenation on antifungal pharmacokinetics: A systematic review

BACKGROUND AND OBJECTIVE

The use of extracorporeal membrane oxygenation (ECMO) as a cardiocirculatory or respiratory support has tremendously increased in critically ill patients. In the setting of ECMO support, invasive fungal infections are a severe cause of morbidity and mortality. This vulnerable population is at risk of suboptimal antifungal exposure due to an increased volume of distribution (Vd), drug sequestration and decreased clearance. Here, we aimed to summarize ex-vivo and clinical studies on the potential impact of ECMO on the pharmacokinetics (PK) of antifungal agents and dosing requirements.

METHODS

A systematic search of the literature within electronic databases PubMed and EMBASE was conducted from database inception to 30 April 2023. Inclusion criteria were as follows: critically ill patients receiving ECMO regardless of age and reporting at least one PK parameter.

RESULTS

Thirty-six studies met inclusion criteria, including seven ex-vivo experiments and 29 clinical studies evaluating three classes of antifungals: polyenes, triazoles and echinocandins. Based on the available ex-vivo PK data, we found a significant sequestration of highly lipophilic and protein-bound antifungals within the ECMO circuit such as voriconazole, posaconazole and micafungin but the PK of several antifungals remains to be addressed such as amphotericin B, isavuconazole and anidulafungin. Most clinical studies have shown increased Vd of some antifungals like fluconazole and micafungin, particularly in the pediatric population. Conflicting data exist about caspofungin exposure.

CONCLUSIONS

The available literature on the antifungal PK changes in ECMO setting is scarce. Whenever possible, therapeutic drug monitoring is highly advised to personalize antifungal therapy.

Population pharmacokinetics of fluconazole in critically ill patients receiving extracorporeal membrane oxygenation and continuous renal replacement therapy: an ASAP ECMO study

This multicenter study describes the population pharmacokinetics (PK) of fluconazole in critically ill patients receiving concomitant extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) and includes an evaluation of different fluconazole dosing regimens for achievement of target exposure associated with maximal efficacy. Serial blood samples were obtained from critically ill patients on ECMO and CRRT receiving fluconazole. Total fluconazole concentrations were measured in plasma using a validated chromatographic assay. A population PK model was developed and Monte Carlo dosing simulations were performed using Pmetrics in R. The probability of target attainment (PTA) of various dosing regimens to achieve fluconazole area under the curve to minimal inhibitory concentration ratio (AUC0-24/MIC) >100 was estimated. Eight critically ill patients receiving concomitant ECMO and CRRT were included. A two-compartment model including total body weight as a covariate on clearance adequately described the data. The mean (±standard deviation, SD) clearance and volume of distribution were 2.87 ± 0.63 L/h and 15.90 ± 13.29 L, respectively. Dosing simulations showed that current guidelines (initial loading dose of 12 mg/kg then 6 mg/kg q24h) achieved >90% of PTA for a MIC up to 1 mg/L. None of the tested dosing regimens achieved 90% of PTA for MIC above 2 mg/L. Current fluconazole dosing regimen guidelines achieved >90% PTA only for Candida species with MIC <1 mg/L and thus should be only used for Candida-documented infections in critically ill patients receiving concomitant ECMO and CRRT. Total body weight should be considered for fluconazole dose.

COVID-19 Is an Independent Risk Factor for Detrimental Invasive Fungal Disease in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: A Retrospective Study

Invasive fungal disease (IFD) is associated with the mortality of patients on extracorporeal membrane oxygenation (ECMO). Several risk factors for IFD have been identified in patients with or without ECMO. Here, we assessed the relevance of coronavirus disease (COVID-19) for the occurrence of IFD in patients on veno-venous (V-V) ECMO for respiratory failure. In a retrospective analysis of all ECMO cases between January 2013 and December 2022 (2020-2022 for COVID-19 patients), active COVID-19 and the type, timing and duration of IFD were investigated. Demographics, hospital, ICU length of stay (LoS), duration of ECMO, days on invasive mechanical ventilation, prognostic scores (Respiratory ECMO Survival Prediction (RESP) score, Charlson Comorbidity Index (CCI), Therapeutic Intervention Scoring System (TISS)-10, Sequential Organ Failure Assessment (SOFA) score and Simplified Acute Physiology Score (SAPS)-II) and length of survival were assessed. The association of COVID-19 with IFD was investigated using propensity score matching and uni- and multivariable logistic regression analyses. We identified 814 patients supported with ECMO, and 452 patients were included in further analyses. The incidence of IFD was 4.8% and 11.0% in patients without and with COVID-19, respectively. COVID-19 status represented an independent risk factor for IFD (OR 4.30; CI 1.72-10.85; p: 0.002; multivariable regression analysis). In patients with COVID-19, 84.6% of IFD was candidemia and 15.4% represented invasive aspergillosis (IA). All of these patients died. In patients on V-V ECMO, we report that COVID-19 is an independent risk factor for IFD, which is associated with a detrimental prognosis. Further studies are needed to investigate strategies of antifungal therapy or prophylaxis in these patients.

Antifungal Dosing in Critically Ill Patients on Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is an established advanced life support system, providing temporary cardiac and/or respiratory support in critically ill patients. Fungal infections are associated with increased mortality in patients on ECMO. Antifungal drug dosing for critically ill patients is highly challenging because of altered pharmacokinetics (PK). PK changes during critical illness; in particular, the drug volume of distribution (Vd) and clearance can be exacerbated by ECMO. This article discusses the available literature to inform adequate dosing of antifungals in this patient population. The number of antifungal PK studies in critically ill patients on ECMO is growing; currently available literature consists of case reports and studies with small sample sizes providing inconsistent findings, with scant or no data for some antifungals. Current data are insufficient to provide definitive empirical drug dosing guidance and use of dosing strategies derived from critically patients not on ECMO is reasonable. However, due to high PK variability, therapeutic drug monitoring should be considered where available in critically ill patients receiving ECMO to prevent subtherapeutic or toxic antifungal exposures.

Treatment and outcome of gram-positive bacteremia in patients receiving extracorporeal membrane oxygenation

BACKGROUND

While guidance exists for management of blood stream infections with various invasive devices, there are currently limited data to guide antibiotic selection and duration for bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO).

OBJECTIVE

To evaluate the treatment and outcomes of thirty-six patients with Staphylococcus aureus and Enterococcus bacteremia on ECMO support.

METHODS

Blood culture data was retrospectively analyzed from patients with Staphylococcus aureus bacteremia (SAB) or Enterococcus bacteremia who underwent ECMO support between March 2012 and September 2021 at Brooke Army Medical Center.

RESULTS

Of the 282 patients who received ECMO during this study period, there 25 (9%) patients developed Enterococcus bacteremia and 16 (6%) developed SAB. SAB occurred earlier in ECMO as compared to Enterococcus (median day 2 IQR (1-5) vs. 22 (12-51), p = 0.01). The most common duration of antibiotics was 28 days after clearance for SAB and 14 days after clearance for Enterococcus. 2 (5%) patients underwent cannula exchange with primary bacteremia, and 7 (17%) underwent circuit exchange. 1/3 (33%) patients with SAB and 3/10 (30%) patients with Enterococcus bacteremia who remained cannulated after completion of antibiotics had a second episode of SAB or Enterococcus bacteremia.

CONCLUSION

This single center case series is the first to describe the specific treatment and outcomes of patients receiving ECMO complicated by SAB and Enterococcus bacteremia. For patients who remain on ECMO after completion of antibiotics, there is a risk of a second episode of Enterococcus bacteremia or SAB.

High Incidence of Candidemia in Critically Ill COVID-19 Patients Supported by Veno-Venous Extracorporeal Membrane Oxygenation: A Retrospective Study

BACKGROUND

The incidence of candidemia in severe COVID-19 patients (0.8-14%) is two- to ten-fold higher than in non-COVID-19 patients.

METHODS

This retrospective analysis aimed to analyse the incidence of bloodstream infections (BSI) due to Candida in a cohort of COVID-19 patients supported with ECMO.

RESULTS

Among 138 intubated and ventilated patients hospitalized for ≥10 days in the intensive care unit of a teaching hospital, 45 (32.6%) patients received ECMO support, while 93 patients (67.4%) did not meet ECMO criteria and were considered the control group. In the ECMO group, 16 episodes of candidaemia were observed, while only 13 in patients of the control group (36.0% vs. 14.0%, p-value 0.004). It was confirmed at the survival analysis (SHR: 2.86, 95% CI: 1.39-5.88) and at the multivariable analyses (aSHR: 3.91, 95% CI: 1.73-8.86). A higher candida score seemed to increase the hazard for candidemia occurrence (aSHR: 3.04, 95% CI: 2.09-4.42), while vasopressor therapy was negatively associated with the outcome (aSHR: 0.15, 95% CI: 0.05-0.43).

CONCLUSIONS

This study confirms that the incidence of candidemia was significantly higher in critically ill COVID-19 patients supported with VV-ECMO than in critically ill COVID patients who did not meet criteria for VV-ECMO.

Impact of extracorporeal membrane oxygenation on voriconazole plasma concentrations: A retrospective study

Aims: We aimed to assess the impact of extracorporeal membrane oxygenation (ECMO) on voriconazole exposure.

Methods: Adult critically ill patients with or without ECMO support receiving intravenous voriconazole therapy were included in this retrospective study conducted in a tertiary referral intensive care unit. The first therapeutic drug monitoring (TDM) results of voriconazole in ECMO patients and non-ECMO patients were collected, and the prevalence of subtherapeutic concentrations was analyzed. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure.

Results: A total of 132 patients (including 66 patients with ECMO support) were enrolled and their respective first voriconazole trough concentrations (C_min) were recorded. The median C_min of the ECMO group and the non-ECMO group was 1.9 (1.4–4.4) and 4.4 (3.2–6.9) mg/L, respectively (p = 0.000), and the proportion of the two groups in subtherapeutic concentrations range (<2 mg/L) was 51.5% and 7.6%, respectively (p = 0.000). Multiple linear regression analysis of voriconazole C_min identified that the use of ECMO and coadministration of glucocorticoids were associated with significantly reduced concentrations, while increasing SOFA score and increasing daily dose were associated with significantly increased concentrations. The model accounted for 32.2% of the variability of voriconazole C_min. Furthermore, binary logistic regression demonstrated that the use of ECMO was an independent risk factor (OR = 7.78, p = 0.012) for insufficient voriconazole exposure.

Conclusion: Our findings showed that, in addition to the known drug interactions, ECMO is a significant covariable affecting voriconazole exposure. In addition, SOFA score was identified as a factor associated with increased voriconazole concentration.

Outcomes of Fungemia in Patients Receiving Extracorporeal Membrane Oxygenation

There are limited data on the treatment of fungal infections complicating extracorporeal membrane oxygenation (ECMO). In 14 patients who developed fungal bloodstream infections on ECMO, eight (57%) survived to discharge. Of the 5 patients completing treatment prior to decannulation, two (40%) developed recurrent fungal infections.