Infections occurring in adult patients receiving mechanical circulatory support: the two-year experience of an Italian National Referral Tertiary Care Center

Incidence, risk factors and outcomes of nosocomial infection in adult patients supported by extracorporeal membrane oxygenation: a systematic review and meta-analysis

BACKGROUND

An increasing number of patients requires extracorporeal membrane oxygenation (ECMO) for life support. This supportive modality is associated with nosocomial infections (NIs). This systematic review and meta-analysis aim to assess the incidence and risk factors of NIs in adult.

METHODS

We searched PubMed, Scopus, Web of Science, and ProQuest databases up to 2022. The primary endpoint was incidence of NI. Secondary endpoints included time to infection, source of infection, ECMO duration, Intensive care and hospital length of stay (LOS), ECMO survival and overall survival. Incidence of NI was reported as pooled proportions and 95% confidence intervals (CIs), while dichotomous outcomes were presented as risk ratios (RR) as the effective index and 95% CIs using a random-effects model.

RESULTS

Among the 4,733 adult patients who received ECMO support in the 30 included studies, 1,249 ECMO-related NIs per 1000 ECMO-days was observed. The pooled incidence of NIs across 18 studies involving 3424 patients was 26% (95% CI 14-38%).Ventilator-associated pneumonia (VAP) and bloodstream infections (BSI) were the most common NI sources. Infected patients had lower ECMO survival and overall survival rates compared to non-infected patients, with risk ratio values of 0.84 (95% CI 0.74-0.96, P = 0.01) and 0.80 (95% CI 0.71-0.90, P < 0.001), respectively.

CONCLUSION

Results showed that 16% and 20% lower of ECMO survival and overall survival in patients with NI than patients without NI, respectively. However, NI increased the risk of in-hospital mortality by 37% in infected patients compared with non-infected patients. In addition, this study identified the significant positive correlation between ECMO duration and ECMO-related NI.

Epidemiology and outcomes of infections during extracorporeal membrane oxygenation in adult patients with COVID-19 ARDS- A single center study

BACKGROUND

There is a scarcity of data regarding nosocomial infections in patients with COVID-19 treated with ECMO. This observational study from India aims to describe the epidemiology and microbiology of infections in patients with COVID-19 associated ECMO.

METHODS

This is an ambi-directional observational study of COVID-19 ECMO patients admitted from April 2021 to June 2022 in a tertiary care hospital. The total number of sepsis episodes for each patient was recorded and were categorized as bloodstream infections (BSI), pneumonias, skin and soft tissue infections (SSTI), invasive candidiasis (IC), catheter associated urinary tract infection (CAUTI), intra-abdominal infections (IAI), and Clostridioides difficile infections. Details regarding each infection including the microbiological profile and outcomes were recorded.

RESULTS

29 patients who received ECMO for COVID-19 pneumonia during the study period were identified. Of the 29 patients, there were a total of 185 septic episodes. The incidence of septic episodes was 72.4 per 1000 ECMO days. Of the 185 sepsis events, 82 (44.3%) were BSI, 72 (39%) were pneumonia, 19 (10.3%) were SSTI, 7 (3.8%) were CAUTI and 5 (2.7%) were IAIs. Of these 29 patients, 16 (55.2%) patients were discharged and 13 (44.8%) died.

CONCLUSIONS

The most common infections in our patients were bloodstream infections followed by pneumonia. High rates of gram negative infections, including those caused by carbapenem resistant bacteria, reflect the Indian critical care unit epidemiology in general. Despite these high infection rates with antimicrobial resistant set of micro-organisms, we had a successful outcome in 55.2% of patients.

A nomogram to predict nosocomial infection in patients on venoarterial extracorporeal membrane oxygenation after cardiac surgery

INTRODUCTION

After cardiac surgery, patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) have a higher risk of nosocomial infection in the intensive care unit (ICU). We aimed to establish an intuitive nomogram to predict the probability of nosocomial infection in patients on VA-ECMO after cardiac surgery.

METHODS

We included patients on VA-ECMO after cardiac surgery between January 2011 and December 2020 at a single center. We developed a nomogram based on independent predictors identified using univariate and multivariate logistic regression analyses. We selected the optimal model and assessed its performance through internal validation and decision-curve analyses.

RESULTS

Overall, 503 patients were included; 363 and 140 patients were randomly divided into development and validation sets, respectively. Independent predictors derived from the development set to predict nosocomial infection included older age, white blood cell (WBC) count abnormality, ECMO environment in the ICU, and mechanical ventilation (MV) duration, which were entered into the model to create the nomogram. The model showed good discrimination, with areas under the curve (95% confidence interval) of 0.743 (0.692-0.794) in the development set and 0.732 (0.643-0.820) in the validation set. The optimal cutoff probability of the model was 0.457 in the development set (sensitivity, 0.683; specificity, 0.719). The model showed qualified calibration in both the development and validation sets (Hosmer-Lemeshow test, p > .05). The threshold probabilities ranged from 0.20 to 0.70.

CONCLUSIONS

For adult patients receiving VA-ECMO treatment after cardiac surgery, a nomogram-monitoring tool could be used in clinical practice to identify patients with high-risk nosocomial infections and provide an early warning.

Body mass index is not associated with time on veno-venous extracorporeal membrane oxygenation or in-hospital mortality

Morbid obesity, as characterized by BMI, is often utilized as an exclusion criterion for VV-ECMO because of presumed poor prognosis and technically complex cannulation. However, the "obesity paradox" suggests obesity may be protective during critical illness, and BMI does not capture variations in body type, adiposity, or fluid balance. This study examines relationships between BMI and patient outcomes. Adult VV-ECMO patients with BMI ≥ 35 kg/m2 admitted January 2012 to June 2021 were identified from an institutional registry. BMI and outcomes were analyzed with Mann-Whitney U tests and Pearson correlations with Bayesian post-hoc analyses. 116 of 960 ECMO patients met inclusion criteria. Median (Q1, Q3) BMI was 42.3 (37.3, 50.8) and min, max of 35.0, 87.8 with 9.0 (5.0, 15.5) ECMO days. BMI was not significantly correlated with ECMO days (r = -0.102; p = .279). Bayesian analyses showed moderate evidence against BMI correlating with ECMO days. In-hospital mortality (27%) was significantly associated with ECMO days (p = .014) but not BMI (p = .485). In this cohort of high-BMI patients, BMI was not associated with survival or time on ECMO. BMI itself should not be used as an exclusion criterion for VV-ECMO.

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.

Impact of Nosocomial Infection on in-Hospital Mortality Rate in Adult Patients Under Venoarterial Extracorporeal Membrane Oxygenation After Cardiac Surgery

Objective

There was no consensus on the impact of nosocomial infection on In-hospital mortality rate in patients receiving ECMO. This study aimed to investigate the impact of nosocomial infection (NI) on In-hospital mortality rate in adult patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) after cardiac surgery.

Materials and Methods

This retrospective study included 503 adult patients who underwent VA-ECMO after cardiac surgery. The impact of time-dependent NIs on In-hospital mortality rate within 28 days of ECMO initiation was investigated using a Cox regression model. The cumulative incidence function for death was compared between patients with NIs and those without NIs using a competing risk model.

Results

Within 28 days after ECMO initiation, 206 (41.0%) patients developed NIs, and 220 (43.7%) patients died. The prevalence rates of NIs were 27.8% and 20.3% during and after ECMO therapy, respectively. The incidence rates of NIs during and after ECMO therapy were 49‰ and 25‰, respectively. Time-dependent NI was an independent risk factor for predicting death (hazard ratio = 1.05, 95% confidence interval = 1.00-1.11). The cumulative incidence of death in patients with NI was significantly higher than that in patients without NI at each time point within 28 days of ECMO initiation. (Z = 5.816, P = 0.0159).

Conclusion

NI was a common complication in adult patients who received VA-ECMO after cardiac surgery, and time-dependent NI was an independent risk factor for predicting mortality in these patients. Using a competing risk model, we confirmed that NIs increased the risk of In-hospital mortality rate in these patients.

Sepsis in postcardiotomy cardiogenic shock patients supported with veno- arterial extracorporeal membrane oxygenation

BACKGROUND

Sepsis could affect the outcomes of patients with postcardiotomy cardiogenic shock supported with extracorporeal membrane oxygenation (ECMO). Our objectives were to characterize sepsis patients with ECMO support for postcardiotomy cardiogenic shock and assess its predictors and effect on patients' outcomes.

METHODS

This retrospective study included 103 patients with ECMO for postcardiotomy cardiogenic shock from 2009 to 2020. Patients were divided according to the occurrence and timing of sepsis into three groups. Group 1 included patients with no sepsis (n = 67), Group 2 included patients with ECMO-related sepsis (n = 10), and Group 3 included patients with non-ECMO-related sepsis (n = 26).

RESULTS

Lactate level before ECMO was highest in the ECMO-associated sepsis group (Group 1 and 2 p = 0.003 and Group 2 and 3 p = 0.003). Dialysis and gastrointestinal bleeding were highest in ECMO-associated sepsis (p = 0.03 and 0.04, respectively). Blood transfusion was higher in ECMO-associated sepsis than in patients with no sepsis (p = 0.01). Mortality was nonsignificantly higher in patients with ECMO-associated sepsis. High BMI (OR: 1.11; p = 0.004), preoperative dialysis (OR: 7.35; p = 0.02), preoperative IABP (OR: 9.9.61; p = 0.01) and CABG (OR: 6.29; p = 0.01) were significantly associated with sepsis. Older age (OR: 1.08; p = 0.004), lower BSA (OR: 0.004; p = 0.003), peripheral cannulation (OR: 29.82; p = 0.03), and high pre ECMO lactate level (OR: 1.24; p = 0.001) were associated with increased mortality. Sepsis did not predict mortality (OR: 1.83; p = 0.21).

CONCLUSIONS

Sepsis is a dreaded complication in patients with postcardiotomy cardiogenic shock, especially ECMO-associated sepsis. Preoperative risk factors could predict postoperative sepsis in ECMO patients.

Variable Sequestration of Antifungals in an Extracorporeal Membrane Oxygenation Circuit

Fungal infections are common and frequently associated with clinical failure in patients receiving extracorporeal membrane oxygenation (ECMO). Antifungal drugs have physicochemical characteristics associated with a higher likelihood of sequestration onto ECMO circuitry potentially leading to a subtherapeutic drug concentration. The percentage of sequestration of the antifungal drugs-caspofungin, posaconazole, and voriconazole-was determined using an ex vivo ECMO model. The circuits were primed with whole human blood, sodium chloride 0.9%, and human albumin solution. Serial 2 ml samples were taken at baseline, 0.5, 1, 2, 6, 12, and 24 hours after drug addition, paired with non-ECMO controls stored in a water bath at 37°C. Mean loss from the blood-primed ECMO circuits and controls at 24 hours relative to baseline were 80% and 61% for caspofungin ( p = ns), 64% and 11% for posaconazole ( p < 0.005), and 27% and 19% for voriconazole ( p < 0.05). Calculated AUC 0-24 showed a 44% for caspofungin ( p = ns), 30.6% posaconazole ( p < 0.005), and 9% loss for voriconazole ( p = 0.003) compared with the controls, suggesting therapeutic concentrations of these antifungal agents cannot be guaranteed with standard dosing in patients on ECMO. Posaconazole exhibited the greatest loss to the ECMO circuit correlating with both high lipophilicity and protein binding of the drug.

Clearance of blood stream infections in patients receiving extracorporeal membrane oxygenation: a retrospective single-center cohort study

BACKGROUND

There are limited data on the treatment of blood stream infections (BSIs) in patients receiving extracorporeal membrane oxygenation (ECMO). Current guidance recommends documenting clearance only in fungal and Gram-positive BSIs. This study investigates the incidence and clinical significance of blood stream infections with positive repeat cultures (BSIPRC) in ECMO as well as clinical factors that may predict positive repeat cultures.

METHODS

All BSIs in patients receiving ECMO at Brooke Army Medical Center between September 2012 and October 2021 were included in this study. BSIPRC was defined as re-isolation of the same organism on repeat blood cultures following an initial positive blood culture.

RESULTS

A total of 60 patients developed 87 BSI (38.5 BSI per 1000 ECMO days). Of the 80 (92%) BSIs who had repeat blood cultures drawn, patients had BSIPRC in 35 (44%) of cases. Fever, leukocytosis, and vasopressor requirement on day of repeat culture were not associated with persistent positivity. There was no difference in survival to discharge for patients with BSIPRC as compared to single day BSI (58% vs. 63%, p = 0.78). 19% of patients with Gram-negative bacteremia had BSIPRC, and gram-negative bacteremia in general was associated with an 83% morality.

CONCLUSIONS

There were no clinical findings that differentiated patients with BSIPRC from those who had a single day of positivity. BSI was associated with high mortality in patients with Gram-negative bacteremia. Given high incidence of positive repeat cultures being seen in Gram-negative BSIs, repeat blood cultures have utility for all BSIs in patients receiving ECMO.

Infections complicating extracorporeal membrane oxygenation in patients with traumatic injuries

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) has increasing utility in adult patients with traumatic injuries. There is currently limited data on the pathogens complicating a trauma patient's ECMO course, making empiric antibiotic decisions difficult. This study aims to characterize the types of infection among patients with traumatic injuries on ECMO.

METHODS

A chart review was performed on all trauma patients at Brooke Army Medical Center receiving ECMO between February 2013 and July 2021. Charts were reviewed to identify pathogens by culture site as well as time to infection following cannulation.

RESULTS

Twenty-one trauma patients underwent ECMO during the study period. The majority of patients were men (90%) with a median age of 30 [IQR 27-38], and a median ECMO course of 9.8 days [IQR 3.9-14.1]. Motor vehicle crashes (81%) accounted for the majority of mechanisms of injury. Of the 24 infections, the majority were respiratory (n = 13, 58/1000 ECMO days) followed by skin and soft tissue (n = 6, 26/1000 ECMO days), blood stream (n = 4, 18/1000 ECMO days), and urinary tract (n = 1, 5/1000 ECMO days). Gram-negative bacteria were the most commonly isolated organism from all sites and at all time periods following cannulation. Multi-drug resistant organisms accounted for 35% (n = 9) of infections and were independent of time from cannulation.

DISCUSSION/CONCLUSION

This is the first study to describe infections in trauma patients requiring ECMO support. We observed majority Gram-negative infections regardless of culture site or time after cannulation. Thus, with infection in this population, empiric antibiotics should have broad spectrum coverage of Gram-negative organisms.

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.

Sepsis Associated with Extracorporeal Membrane Oxygenation

Sepsis in patients on extracorporeal membrane oxygenation (ECMO) remains a serious complication. Its presence is a poor prognostic marker and increases overall mortality. Adult patients with prolonged duration on ECMO are at high risk of developing sepsis. Ventilator-associated pneumonia and bloodstream infections are the main sources of infection these patients. A strong early suspicion, drawing adequate volume for blood cultures, and early and timely administration of empirical antibiotics can help control the infection and decrease the morbidity and mortality. The diagnostic and the treatment are both challenging. Cardiac patients have increased risk of nosocomial infection while on ECMO, which may be in part due to longer cannulation times, as well as increased likelihood of undergoing major procedures or having an open chest.

Outcome and Clinical Characteristics of Nosocomial Infection in Adult Patients Undergoing Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

Objective

This study conducts a meta-analysis of clinical outcomes of nosocomial infection in adult patients receiving extracorporeal membrane oxygenation (ECMO) and systematically evaluates clinical epidemiological characteristics.

Methods

Document retrieval strategies were determined, and all adult patients treated by ECMO were included. The prevalence, incidence, mortality, ECMO use time, intensive care unit (ICU) stay time, hospital stay time, and risk factors of nosocomial infection were systematically evaluated. Subsequently, a meta-analysis of the impact of nosocomial infection on risk of in-hospital mortality was conducted.

Results

A total of 25 retrospective studies were included, and 19 studies were included in the meta-analysis. The prevalence of nosocomial infection was 8.8–64.0%, incidence was 1.7–85.4‰ (per 1,000 ECMO days), and in-hospital mortality was 31.5–75.4%. The duration of ECMO usage and length of ICU stay were longer for infected patients. Compared with non-infected patients, the meta-analysis revealed that nosocomial infection increased the relative risk of death of adult patients receiving ECMO by 32%. The risk factors included the duration of ECMO usage and disease severity score.

Conclusions

Adult patients treated by ECMO have high prevalence of nosocomial infection. In addition, their ECMO use time and ICU stays are longer. Nosocomial infection significantly increases the relative risk of in-hospital mortality.

[Severe Candida sepsis in a 28-year-old female patient with initial diagnosis of diabetes mellitus and marked hyperosmolar coma]

We report on a 28-year-old female patient who had no history of diseases and who was brought to our intensive care unit in a comatose state by the ambulance service. The clinical picture corresponded to sepsis with a massively increased blood sugar concentration (> 2000 mg/dl) as well as a pronounced skin mycosis in the groin region of the very obese patient (body mass index [BMI]: 33.7 kg/m²) in the physical examination. The treatment of sepsis was initially supplemented by a calculated antifungal treatment. The blood culture diagnosis confirmed the presence of Candida albicans and Candida glabrata. Despite adequate anti-infective treatment, the patient developed a septic shock in the further course, so that the additional escalation of treatment was initiated by renal replacement therapy on the second day and venovenous extracorporeal membrane oxygenation because of an ARDS. Despite all of these measures and maximum intensive care treatment, the patient developed a progressive multiple organ failure. When the pupils became rigid to light, a cerebral computed tomography was carried out. This showed evidence of a severe cerebral edema without signs of cerebral bleeding. Multiple examinations of somatosensory evoked potentials and electroencephalograms showed signs of irreversible brain damage. In view of this poor prognosis the therapeutic measures were limited. The patient died on day 24 after admission to the intensive care unit. The case study shows that antifungal treatment should definitely be considered in the context of sepsis treatment if there is a clinically justified suspicion.The role of the severely altered metabolic situation with massive hyperglycemia and ketoacidosis cannot be finally assessed.

Rates of nosocomial infection associated with interhospital transfer of patients receiving extracorporeal membrane oxygenation

OBJECTIVES

Critically ill patients requiring extracorporeal membrane oxygenation (ECMO) frequently require interhospital transfer to a center that has ECMO capabilities. Patients receiving ECMO were evaluated to determine whether interhospital transfer was a risk factor for subsequent development of a nosocomial infection.

DESIGN

Retrospective cohort study.

SETTING

A 425-bed academic tertiary-care hospital.

PATIENTS

All adult patients who received ECMO for >48 hours between May 2012 and May 2020.

METHODS

The rate of nosocomial infections for patients receiving ECMO was compared between patients who were cannulated at the ECMO center and patients who were cannulated at a hospital without ECMO capabilities and transported to the ECMO center for further care. Additionally, time to infection, organisms responsible for infection, and site of infection were compared.

RESULTS

In total, 123 patients were included in analysis. For the primary outcome of nosocomial infection, there was no difference in number of infections per 1,000 ECMO days (25.4 vs 29.4; P = .03) by univariate analysis. By Cox proportional hazard analysis, transport was not significantly associated with increased infections (hazard ratio, 1.7; 95% confidence interval, 0.8-4.2; P = .20).

CONCLUSION

In this study, we did not identify an increased risk of nosocomial infection during subsequent hospitalization. Further studies are needed to identify sources of nosocomial infection in this high-risk population.

Risk factors and prognosis of nosocomial pneumonia in patients undergoing extracorporeal membrane oxygenation: a retrospective study

Objective

We aimed to examine the risk factors and prognosis of nosocomial pneumonia (NP) during extracorporeal membrane oxygenation (ECMO).

Methods

We retrospectively analyzed data of patients who received ECMO at the Affiliated Hangzhou Hospital of Nanjing Medical University between January 2013 and August 2019. The primary outcome was the survival-to-discharge rate.

Results

Sixty-nine patients who received ECMO were enrolled, median age 42 years and 26 (37.7%) women; 14 (20.3%) patients developed NP. The NP incidence was 24.7/1000 ECMO days. Patients with NP had a higher proportion receiving veno-venous (VV) ECMO (50% vs. 7.3%); longer ECMO support duration (276 vs. 140 hours), longer ventilator support duration before ECMO weaning (14.5 vs. 6 days), lower ECMO weaning success rate (50.0% vs. 81.8%), and lower survival-to-discharge rate (28.6% vs. 72.7%) than patients without NP. Multivariable analysis showed independent risk factors that predicted NP during ECMO were ventilator support duration before ECMO weaning (odds ratio [OR] = 1.288; 95% confidence interval [CI]: 1.111–1.494) and VV ECMO mode (OR = 10.970; 95% CI: 1.758–68.467).

Conclusion

NP during ECMO was associated with ventilator support duration before ECMO weaning and VV ECMO mode. Clinicians should shorten the respiratory support duration for patients undergoing ECMO to prevent NP.

Different characteristics of bloodstream infection during venoarterial and venovenous extracorporeal membrane oxygenation in adult patients

Currently, there is scarcity of data on whether differences exist in clinical characteristics and outcomes of bloodstream infection (BSI) between venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) and whether they differ between Candida BSI and bacteremia in adult ECMO patients. We retrospectively reviewed data of patients who required ECMO for > 48 h and had BSIs while receiving ECMO between January 2015 and June 2020. Cases with a positive blood culture result within 24 h of ECMO implantation were excluded. We identified 94 (from 64 of 194 patients) and 38 (from 17 of 56 patients) BSI episodes under VA and VV ECMO, respectively. Fifty nine BSIs of VA ECMO (59/94, 62.8%) occurred in the first 2 weeks after ECMO implantation, whereas 24 BSIs of VV ECMO (24/38, 63.2%) occurred after 3 weeks of ECMO implantation. Gram-negative bacteremia (39/59, 66.1%) and gram-positive bacteremia (10/24, 41.7%) were the most commonly identified BSI types in the first 2 weeks after VA ECMO implantation and after 3 weeks of VV implantation, respectively. Timing of Candida BSI was early (6/11, 54.5% during the first 2 weeks) in VA ECMO and late (6/9, 66.7% after 3 weeks of initiation) in VV ECMO. Compared with bacteremia, Candida BSI showed no differences in clinical characteristics and outcomes during VA and VV ECMO, except the significant association with prior exposure to carbapenem in VA ECMO (vs. gram-negative bacteremia [P = 0.006], vs. gram-positive bacteremia [P = 0.03]). Our results suggest that ECMO modes may affect BSI clinical features and timing. In particular, Candida BSI occurrence during the early course of VA ECMO is not uncommon, especially in patients with prior carbapenem exposure; however, it usually occurs during the prolonged course of VV ECMO. Consequently, routine blood culture surveillance and empiric antifungal therapy might be warranted in targeted populations of adult ECMO patients, regardless of levels of inflammatory markers and severity scores.

Infectious complications associated with short-term mechanical circulatory support in urgent heart transplant candidates

INTRODUCTION AND OBJECTIVES

Short-term mechanical circulatory support is frequently used as a bridge to heart transplant in Spain. The epidemiology and prognostic impact of infectious complications in these patients are unknown.

METHODS

Systematic description of the epidemiology of infectious complications and analysis of their prognostic impact in a multicenter, retrospective registry of patients treated with short-term mechanical devices as a bridge to urgent heart transplant from 2010 to 2015 in 16 Spanish hospitals.

RESULTS

We studied 249 patients, of which 87 (34.9%) had a total of 102 infections. The most frequent site was the respiratory tract (n=47; 46.1%). Microbiological confirmation was obtained in 78 (76.5%) episodes, with a total of 100 causative agents, showing a predominance of gram-negative bacteria (n=58, 58%). Compared with patients without infection, those with infectious complications showed higher mortality during the support period (25.3% vs 12.3%, P=.009) and a lower probability of receiving a transplant (73.6% vs 85.2%, P=.025). In-hospital posttransplant mortality was similar in the 2 groups (with infection: 28.3%; without infection: 23.4%; P=.471).

CONCLUSIONS

Patients supported with temporary devices as a bridge to heart transplant are exposed to a high risk of infectious complications, which are associated with higher mortality during the organ waiting period.

Bloodstream infections in patients undergoing extracorporeal membrane oxygenation

Objective:

We aimed to evaluate the incidence, risk factors, and prognosis of bloodstream infections (BSIs) during extracorporeal membrane oxygenation (ECMO) treatment in a Chinese population.

Methods:

Patients receiving ECMO treatment from January 2013 to August 2019 were retrospectively studied. The incidence of BSIs was calculated. The clinical characteristics between patients with a BSI (BSI group) and without a BSI (non-BSI group)

Results:

Among 69 included patients, 19 (27.5%) developed at least one BSI. Gram-negative bacteria (73.7%) were mainly responsible for the BSIs, with Klebsiella pneumoniae (6/19, 31.5%) ranking as the top related pathogen. The BSI group had a greater proportion of methicillin-resistant Staphylococcus aureus (MRSA) prophylactic regimens (52.6% vs. 26.0%, P = 0.036), a higher pre-ECMO Sequential Organ Failure Assessment (SOFA) score (11 vs. 8, P = 0.008), more applications of continuous renal replacement therapy (CRRT) during ECMO (63.1% vs. 36.1%, P = 0.042). Longer ECMO support duration, period of ventilator use before ECMO weaning and hospital stay were observed in the BSI group. The SOFA score (OR: 1.174; 95% CI: 1.039–1.326; P = 0.010) was an independent risk factor for BSIs.

Conclusion:

BSIs during ECMO therapy frequently involve Gram-negative bacteria. Stringent care and monitoring should be provided for patients with high SOFA scores.

Risk factor analysis of nosocomial lower respiratory tract infection in influenza-related acute respiratory distress syndrome

Background:

Patients with severe influenza-related acute respiratory distress syndrome (ARDS) have high morbidity and mortality. Moreover, nosocomial lower respiratory tract infection (NLRTI) complicates their clinical management and possibly worsens their outcomes. This study aimed to explore the clinical features and impact of NLRTI in patients with severe influenza-related ARDS.

Methods:

This was an institutional review board approved, retrospective, observational study conducted in eight medical centers in Taiwan. From January 1 to March 31 in 2016, subjects were enrolled from intensive care units (ICUs) with virology-proven influenza pneumonia, while all of those patients with ARDS requiring invasive mechanical ventilation and without bacterial community-acquired pneumonia (CAP) were analyzed. Baseline characteristics, critical-illness data and clinical outcomes were recorded.

Results:

Among the 316 screened patients with severe influenza pneumonia, 250 with acute respiratory failure requiring intubation met the criteria of ARDS, without having bacterial CAP. Among them, 72 patients developed NLRTI. The independent risk factors for NLRTI included immunosuppressant use before influenza infection [odds ratio (OR), 5.669; 95% confidence interval (CI), 1.770–18.154], extracorporeal membrane oxygenation (ECMO) use after ARDS (OR, 2.440; 95% CI, 1.214–4.904) and larger corticosteroid dosage after ARDS (OR, 1.209; 95% CI, 1.038–1.407). Patients with NLRTI had higher in-hospital mortality and longer ICU stay, hospitalization and duration on mechanical ventilation.

Conclusion:

We found that immunosuppressant use before influenza infection, ECMO use, and larger steroid dosage after ARDS independently predict NLRTI in influenza-related ARDS. Moreover, NLRTI results in poorer outcomes in patients with severe influenza.

The reviews of this paper are available via the supplemental material section.

Sepsis and ECMO

Sepsis is being recognized as an important complication of extracorporeal membrane oxygenation (ECMO) and its presence is a poor prognostic marker and increases the overall mortality. The survival rate differs in the various types of cannulation techniques. Adult patients with prolonged duration of ECMO constitute the major risk population. Ventilator-associated pneumonia and bloodstream infections form the main sources of sepsis in these patients. It is important to know the most common etiological agents for sepsis in ECMO, which varies partly with the local epidemiology of the hospitals. A high index of suspicion, drawing adequate volumes for blood culture and early and timely administration of appropriate empirical antimicrobials can substantially decrease the morbidity and mortality in this high-risk population. The dosing of antimicrobials is influenced by the pharmacological variations on ECMO machine and is an important consideration. Infection control practices are of paramount importance and need to be followed meticulously to prevent sepsis in ECMO.

Nosocomial Infections During Extracorporeal Membrane Oxygenation in Neonatal, Pediatric, and Adult Patients: A Comprehensive Narrative Review

OBJECTIVES

Extracorporeal membrane oxygenation is increasingly used in critically ill patients with refractory cardiopulmonary failure. Nosocomial infection acquired during extracorporeal membrane oxygenation represents one of the most frequent complications but the available evidence on the risk of infection and its association with outcomes has not been comprehensively analyzed. We performed a narrative review examining the epidemiology of nosocomial infection during extracorporeal membrane oxygenation, association with clinical outcomes, and preventive strategies.

DATA SOURCES

We searched PubMed, Web of Science, EMBASE, and the Cochrane Library between 1972 and June 2018.

STUDY SELECTION

We included any article which detailed nosocomial infection during extracorporeal membrane oxygenation. Articles were excluded if they were not written in English, detailed extracorporeal membrane oxygenation use for infections acquired prior to extracorporeal membrane oxygenation, or used other forms of extracorporeal support such as ventricular assist devices.

DATA EXTRACTION

Two reviewers independently assessed eligibility and extracted data. We screened 984 abstracts and included 59 articles in the final review.

DATA SYNTHESIS

The reported risk of nosocomial infection among patients receiving extracorporeal membrane oxygenation ranged from 3.5% to 64% per extracorporeal membrane oxygenation run, while the incidence of infection ranged from 10.1 to 116.2/1,000 extracorporeal membrane oxygenation days. Nosocomial infections during extracorporeal membrane oxygenation were consistently associated with longer duration of extracorporeal membrane oxygenation and, in several large multicenter studies, with increased mortality. Risk factors for nosocomial infection included duration of extracorporeal membrane oxygenation, mechanical and hemorrhagic complications on extracorporeal membrane oxygenation, and use of venoarterial and central extracorporeal membrane oxygenation. Biomarkers had low specificity for infection in this population. Few studies examined strategies on how to prevent nosocomial infection on extracorporeal membrane oxygenation.

CONCLUSIONS

Nosocomial infections in extracorporeal membrane oxygenation patients are common and associated with worse outcomes. There is substantial variation in the rates of reported infection, and thus, it is possible that some may be preventable. The evidence for current diagnostic, preventive, and therapeutic strategies for infection during extracorporeal membrane oxygenation is limited and requires further investigation.

ECLS-associated infections in adults: what we know and what we don't yet know

Extracorporeal life support (ECLS) is increasingly used in the management of patients with severe cardiopulmonary disease. Infections are frequently the etiologies underlying the respiratory, and occasionally cardiac, failure that necessitates ECLS. Just as importantly, infections are among the most commonly reported adverse events during ECLS. Infections in this setting may be the sequelae of prolonged critical illness or of underlying immune dysregulation; they may be hospital-acquired infections, and they may or may not be attributable to the presence of ECLS itself, the latter being an aspect that can be difficult to determine. Current registry data and evidence from the literature offer some insights, but also leave open many questions regarding the nature and significance of infections reported both before and during ECLS, including the question of any causal link between ECLS and the development of infections. An ongoing lack of consistency in the identification, diagnosis, management, and prevention of infections during ECLS is limiting our ability to interpret literature data and thus highlighting the need for more rigorous investigation and standardization of definitions. This review aims to characterize the current understanding of infections associated with the use of ECLS, taking into account data from the updated Extracorporeal Life Support Organization Registry, which provides important context for understanding the epidemiology and outcomes of these patients.

Infections in patients with burn injuries receiving extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) has only recently been described in patients with burn injuries. We report the incidence and type of infections in critically ill burn and non-burn patients receiving ECMO.

METHODS

A retrospective chart review was performed on all patients at Brooke Army Medical Center who received ECMO between September 2012 and May 2018.

RESULTS

78 patients underwent ECMO. Approximately half were men with a median age of 34 years with a median time on ECMO of 237 h (IQR 121-391). Compared to patients without burns (n = 58), patients with burns (n = 20) had no difference in time on ECMO, but had more overall infections (86 vs. 31 per 1000 days, p = 0.0002), respiratory infections (40 vs. 15 per 1000 days, p = 0.01), skin and soft tissue infections (21 vs. 5 per 1000 days, p = 0.02) and fungal infections (35% vs 10%, p = 0.02). Twenty percent of bacterial burn infections were due to drug resistant organisms.

CONCLUSION

This is the first study to describe the incidence of infection in burn injury patients who are undergoing ECMO. We observed an increase in infections in burn patients on ECMO compared to non-burn patients. ECMO remains a viable option for critically ill patients with burn injuries.

Invasive fungal infection in crtically ill patients: hurdles and next challenges

A narrative review from a multidisciplinary task force of experts in critical care medicine and clinical mycology was carried out. The multi drug-resistant species Candida auris has emerged simultaneously on several continents, causing hospital outbreaks, especially in critically ill patients. Although there are not enough data to support the routine use of continuous antibiotic prophylaxis in patients subjected to extracorporeal membrane oxygenator, a clear increase of invasive fungal infection (IFI) has been described with the use of this device. Possible IFI treatment failures could be related with suboptimal antifungal concentrations despite dose adjustment. Invasive aspergillosis has become an important life-threating infection in intensive care unit related with new risk factors described. IFI remain important problem in critical patients due to the appearance of new risk factors, new species, and resistance increase. Multidisciplinary packages of measures designed to reduce IFI incidence and improve diagnostics tools may reduce the high mortality associated.

Epidemiology and risk factors for nosocomial infection in the respiratory intensive care unit of a teaching hospital in China: A prospective surveillance during 2013 and 2015

BACKGROUND

To determine the epidemiology and risk factors for nosocomial infection (NI) in the Respiratory Intensive Care Unit (RICU) of a teaching hospital in Northwest China.

METHODS

An observational, prospective surveillance was conducted in the RICU from 2013 to 2015. The overall infection rate, distribution of infection sites, device-associated infections and pathogen in the RICU were investigated. Then, the logistic regression analysis was used to test the risk factors for RICU infection.

RESULTS

In this study, 102 out of 1347 patients experienced NI. Among them, 87 were device-associated infection. The overall prevalence of NI was 7.57% with varied rates from 7.19 to 7.73% over the 3 years. The lower respiratory tract (43.1%), urinary tract (26.5%) and bloodstream (20.6%) infections accounted for the majority of infections. The device-associated infection rates of urinary catheter, central catheter and ventilator were 9.8, 7.4 and 7.4 per 1000 days, respectively.The most frequently isolated pathogens were Staphylococcus aureus (20.9%), Klebsiella pneumoniae (16.4%) and Pseudomonas aeruginosa (10.7%). Multivariate analysis showed that the categories D or E of Average Severity of Illness Score (ASIS), length of stay (10-30, 30-60, ≥60 days), immunosuppressive therapy and ventilator use are the independent risk factors for RICU infection with an adjusted odds ratio (OR) of 1.65 (95% CI: 1.15~2.37), 5.22 (95% CI: 2.63~10.38)), 2.32 (95% CI: 1.19~4.65), 8.93 (95% CI: 3.17~21.23), 31.25 (95% CI: 11.80~63.65)) and 2.70 (95% CI: 1.33~5.35), respectively.

CONCLUSION

A relatively low and stable rate of NI was observed in our RICU through year 2013-2015. The ASIS-D、E, stay ≥10 days, immunosuppressive therapy and ventilator use are the independent risk factors for RICU infection.

Bloodstream infections during post-cardiotomy extracorporeal membrane oxygenation: Incidence, risk factors, and outcomes

Introduction:

Veno-arterial extracorporeal membrane oxygenation after heart surgery is a relatively common procedure. It is easily applicable but associated with a number of complications, including bloodstream infections. The aim of this study is to determine the current rate and the risk factors related to bloodstream infections acquired during post-cardiotomy veno-arterial extracorporeal membrane oxygenation.

Methods:

Single-center retrospective study. From the overall population receiving any kind of extracorporeal membrane oxygenation from March 2013 through December 2017, the post-cardiotomy patient population was extracted, with a final sample of 92 veno-arterial extracorporeal membrane oxygenations. The risk of developing bloodstream infections as a function of extracorporeal membrane oxygenation exposure was analyzed with appropriate statistical analyses, including a Kaplan–Meier analysis.

Results:

Overall, 14 (15.2%) patients developed a bloodstream infection during extracorporeal membrane oxygenation or within the first 48 h after extracorporeal membrane oxygenation removal. The total extracorporeal membrane oxygenation duration in the population was 567 days, and the incidence of bloodstream infections was 24.7 bloodstream infections/1000 extracorporeal membrane oxygenation days. There was a progressive increase in the cumulative hazard ratio during the first 7 days, reaching a value of 20% on day 7; from day 7 and day 15, the hazard ratio remained stable, with a second increase after day 15. The independent risk factors associated with bloodstream infections were adult age, pre-implantation serum total bilirubin level, and the amount of chest drain blood loss.

Discussion:

Infections acquired during veno-arterial extracorporeal membrane oxygenation are common. Identify the risk factors that may improve strategies for treatment and prevention.

Ventilator-associated pneumonia in extracorporeal membrane oxygenation-assisted patients

Extracorporeal membrane oxygenation (ECMO) provides a circulatory and/or respiratory assistance in case of refractory cardiogenic shock or acute respiratory distress syndrome (ARDS). Due to their extreme critical illness, these patients usually require prolonged mechanical ventilation, which is an inherent risk of ventilator-associated pneumonia (VAP). Although microorganisms responsible of VAP on ECMO are similar to those found in non-ECMO patients, classical suspicion criteria of VAP are no longer relevant on ECMO. Frequent severe chest X-Ray impairments, and poor specificity of the classical biomarkers on ECMO make VAP diagnosis challenging. In addition, significant drug pharmacokinetic modifications by the device may lead to low plasmatic antibiotic concentration and potential treatment failure. Consequently, rate of treatment failure and relapse appear high in that population (up to 30%), with significant impact on mortality and on the ECMO duration.

Incidence of nosocomial infections in adult patients undergoing extracorporeal membrane oxygenation

INTRODUCTION

Critically ill patients requiring extracorporeal membrane oxygenation (ECMO) are at increased risk for developing nosocomial infections owing to their underlying disease process along with numerous invasive monitoring devices.

METHODS

We retrospectively analyzed the rate, type, pathogens, outcomes, and risk factors of nosocomial infections that developed during adult patients on ECMO at our institution from 2012-2015.

RESULTS

Compared to current ELSO reported adult nosocomial infections rate of 20.5%, we report our rate of 26% (CI 17.2%-34.7%). No significant differences were observed in mortality (42.3% vs. 36.5%; p=0.598), and presence of either antibiotics prior to ECMO (57.7% vs. 56.7%; p=0.934) or culture-proven infection prior to ECMO (19.2% vs. 32.4%; p=0.201). Patients who developed nosocomial infections had longer duration of ECMO (13 vs. 5 days; p<0.001), longer length of stay (36.5 vs. 18.5 days; p=0.004), and more days on ventilator (29 vs. 12.5; p=0.002). Duration of ECMO (OR=1.20, 95% CI 1.02-1.39; p=0.020) and duration of ECMO greater than 10 days (OR=14.65, 95% CI 1.81-118.78; p=0.012) were independent risk factors for developing nosocomial infections. However, there was no difference in mortality when duration of ECMO >10 days was compared with ≤10 days (28.5% vs. 43.1%; p=0.154).

CONCLUSION

Nosocomial infections have no effect on survival in adult ECMO patients. Presence of either antibiotics or infection prior to ECMO has no effect on developing nosocomial infections while on ECMO. Duration of ECMO longer than 10 days is a major risk factor for developing nosocomial infection.

Invasive pulmonary aspergillosis is associated with adverse clinical outcomes in critically ill patients receiving veno-venous extracorporeal membrane oxygenation

To identify the incidence, risk factors and impact on long-term survival of invasive pulmonary aspergillosis (IPA) and Aspergillus colonisation in patients receiving vv-extracorporeal membrane oxygenation (ECMO). A retrospective evaluation was performed of patients receiving vv-ECMO at a tertiary hospital in Manchester (UK) between January 2012 and December 2016. Data collected included epidemiological data, microbiological cultures, radiographic findings and outcomes. Cases were classified as proven IPA, putative IPA or Aspergillus colonisation according to a validated clinical algorithm. One hundred thirty-four patients were supported with vv-ECMO, median age of 45.5 years (range 16.4-73.4). Ten (7%) patients had putative IPA and nine (7%) had Aspergillus colonisation. Half of the patients with putative IPA lacked classical host risk factors for IPA. The median number of days on ECMO prior to Aspergillus isolation was 5 days. Immunosuppression and influenza A infection were significantly associated with developing IPA in a logistic regression model. Cox regression model demonstrates a three times greater hazard of death associated with IPA. Overall 6-month mortality rate was 38%. Patients with putative IPA and colonised patients had a 6-month mortality rate of 80 and 11%, respectively. Immunosuppression and influenza A infection are independent risk factors for IPA. IPA, but not Aspergillus colonisation, is associated with high long-term mortality in patients supported with vv-ECMO.

Extracorporeal membrane oxygenation line-associated complications: in vitro testing of cyanoacrylate tissue adhesive and securement devices to prevent infection and dislodgement

Background

Extracorporeal membrane oxygenation (ECMO) delivers cardiac and/or respiratory support to critically ill patients who have failed conventional medical therapies. If the large-bore cannulas used to deliver ECMO become infected or dislodged, the patient consequences can be catastrophic. ECMO cannula-related infection has been reported to be double the rate of other vascular devices (7.1 vs 3.4 episodes/1000 ECMO days respectively). The aim of this study was to assess the ability of cyanoacrylate tissue adhesive (TA) to inhibit bacterial growth at the ECMO cannulation site, and the effectiveness of TA and securement devices in securing ECMO cannulas and tubing.

Methods

This in vitro study tested the (1) antimicrobial qualities of TA against standard transparent dressing with ECMO cannula; (2) chemical compatibility between cannula, TA and removal agent; (3) pull-out strength of transparent dressing and TA at the cannula insertion site; and (4) pull-out strength of adhesive bandage and commercial sutureless securement devices (SSDs) on circuit tubing. Fisher’s exact test was used to evaluate differences in bacterial growth observed between the transparent dressing and TA groups. Data from mechanical testing were analysed using one-way ANOVA, followed by Tukey’s multiple comparison test or t test as appropriate. Statistical significance was defined as p < 0.05.

Results

No bacterial growth occurred under TA-covered cannulas compared with transparent dressing-covered cannulas (p = 0.002). Compared to plates lacking TA or transparent dressing, growth was observed at the insertion point and under the dressing in the transparent dressing group; however, no growth was observed in the TA group (p = 0.019). TA did not weaken the cannulas; however, the TA removal agent did after 60 min of exposure, compared with control (p < 0.01). Compared with transparent dressing, TA increased the pull-out force required for cannula dislodgement from the insertion point (p < 0.0001). SSDs significantly increased the force required to remove the tubing from the fixation points compared with adhesive bandage (p < 0.01).

Conclusions

Our findings suggest that the combined use of TA at the cannula insertion site with a commercial device for tubing securement could provide an effective bedside strategy to prevent or minimise infection and line dislodgement.

Infectious complications in paediatric patients treated with extracorporeal membrane oxygenation

INTRODUCTION

The aim of this study was to analyse the incidence, treatment and evolution of infections in children treated with ECMO.

METHODS

A retrospective study based on a prospective database was performed. Children under the age of 18 years treated with ECMO from September 2006 to November 2015 were included. The patients' clinical characteristics were collected, together with ECMO technique, cultures and treatment of infection.

RESULTS

One hundred patients with a median age of 11 months were analysed. Heart disease was diagnosed in 94 patients. An infection was suspected and antibiotic treatment was initiated in 51 patients, although only 22 of them were microbiologically confirmed. The most common infection was sepsis (49%), followed by pneumonia (35.3%) and urinary tract infection (9.8%). There were no differences in haematological parameters and acute phase reactants between children with infection and those without. Children who died had a higher incidence of infection during ECMO (60.4%) than the survivors (40.3%), but the difference did not reach statistical significance (P=.07). The duration of admission in the PICU was 57 days in patients with infection vs 37 days in patients without infection but the difference was not statistically significant (P=.067).

CONCLUSIONS

Infection in children with ECMO is common. There are no specific infection parameters and less than half of the clinical infections are confirmed microbiologically. There was no statistically significant correlation between infection and mortality or duration of PICU stay.

Mechanical circulatory support in lung transplantation: Cardiopulmonary bypass, extracorporeal life support, and ex-vivo lung perfusion

Lung transplant is the standard of care for patients with end-stage lung disease refractory to medical management. There is currently a critical organ shortage for lung transplantation with only 17% of offered organs being transplanted. Of those patients receiving a lung transplant, up to 25% will develop primary graft dysfunction, which is associated with an 8-fold increase in 30-d mortality. There are numerous mechanical lung assistance modalities that may be employed to help combat these challenges. We will discuss the use of mechanical lung assistance during lung transplantation, as a bridge to transplant, as a treatment for primary graft dysfunction, and finally as a means to remodel and evaluate organs deemed unsuitable for transplant, thus increasing the donor pool, improving survival to transplant, and improving overall patient survival.