Impact of bloodstream infections on catheter colonization during extracorporeal membrane oxygenation

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.

Biofilm Assessment and Metagenomic Analysis of Venoarterial Extracorporeal Membrane Oxygenation Cannulas and Membrane Oxygenators

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) exposes the patient to infectious complications related to the cannulas or the site of insertion. The aim of the current study was to investigate and compare the prevalence of cannula and membrane oxygenators colonization using three different methods: microbiological culture, scanning electron microscopy, and metagenomic (rRNA 16S analysis). A monocentric prospective study was conducted between December 2017 and June 2018. Consecutive patients undergoing VA-ECMO support for refractory cardiac arrest or cardiogenic shock were included. Ten patients were included with a median age of 64 (52-62) years. Venoarterial extracorporeal membrane oxygenation was inserted for refractory cardiac arrest in five (50%), cardiogenic shock in four (40%), and self-poisoning in one (10%) cases. Microbiological culture of all (8/8, 100%) membrane oxygenators was negative, whereas all (10/10, 100%) were colonized by biofilm, and eight (8/9, 89%) presented bacterial DNA. Three (3/9, 33%) arterial and venous cannulas were positive in culture and seven (7/9, 78%) were colonized by biofilm, respectively. Seven (7/9, 78%) arterial and four (4/9, 44%) venous cannulas presented bacterial DNA. Colonization of cannulas and membranes is more frequent when assessed by electron microscopy or metagenomic analysis than with culture. Membrane oxygenators are more often colonized than cannulas.

Infection in ECMO patients: Changes in epidemiology, diagnosis and prevention

Patients with prolonged duration of extracorporeal membrane oxygenation support (ECMO) are a vulnerable population for sepsis, particularly ventilator-associated pneumonia and bloodstream infections. Rates differ between venous-arterial and venous-venous ECMO patients and according to the cannulation technique used. The presence of particular organisms depends on local epidemiology, antibiotic exposure, and the duration of the intervention; patients undergoing ECMO for more than three weeks present a high risk of persistent candidemia. Recognizing predisposing factors, and establishing the best preventive interventions and therapeutic choices are critical to optimizing the management of these complications. Infection control practices, including shortening the period of the indwelling devices, and reducing antibiotic exposure, must be followed meticulously. Innovations in oxygenator membranes require an updated approach. Hand hygiene and avoiding breaking the circuit-oxygenator sterility are cornerstones. ECMO management would benefit from clearer definitions, optimization of infection control strategies, and updated infectious clinical practice guidelines.

Effectiveness of a Game-Based Mobile App for Educating Intensive Critical Care Specialist Nurses in Extracorporeal Membrane Oxygenation Pipeline Preflushing: Quasi-Experimental Trial

Background

In the context of training specialist nurses and nursing education, a game-based mobile app was used as a simulation to teach intensive critical care specialist nurses the knowledge and skills of extracorporeal membrane oxygenation (ECMO) pipeline preflushing.

Objective

This study aimed to evaluate the impact of a game-based mobile app on improving ECMO pipeline preflushing skills in intensive critical care specialist nurses.

Methods

A total of 86 intensive critical care specialist nurses who were learning ECMO for the first time were included in this study. The nurses were divided into 2 groups: a control group (n=43) and an experimental group (n=43). Participants in the experimental group used a game-based mobile app for simulation exercises; the control group received no additional intervention. All participants took a theoretical test and a skill operation test at the beginning of the study and 1 week later. The differences in scores between the 2 groups were compared, and the learning curve of the experimental group was observed.

Results

The final theoretical test scores (88.44 and 85.02) and skill operation test scores (89.42 and 86.33) of the experimental group and control group, respectively, were significantly higher than those of the initial tests (theoretical test scores: 75.88 and 74.42; skill operation test scores: 75.44 and 75.93; all P<.001). The scores of the final theoretical test (88.44) and the final skill operation test (89.42) in the experimental group were higher than the scores of the control group (85.02; P<.001 and 86.33; P<.001, respectively). Learning curve analysis showed that the experimental group needed an average of 17 operations to master the skill.

Conclusions

This study suggests that a game-based mobile app may be more effective for intensive critical care specialist nurses in ECMO pipeline preflushing education than traditional Chinese lecture-practice education.

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.

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.

Nosocomial infections during extracorporeal membrane oxygenation

PURPOSE OF THE REVIEW

The aim of this review is to present the latest evidence regarding the prevention, diagnosis and treatment of nosocomial infections during extracorporeal membrane oxygenation (ECMO) support.

RECENT FINDINGS

New descriptive data from the Extracorporeal Life Support Organisation (ELSO) registry and single centre studies have been published. In parallel, there is an increase in the availability of evidence about the diagnostic accuracy of infection markers, yield of routine cultures, effectivity of antibiotic prophylaxis and other preventive measures.

SUMMARY

ECMO is a rescue therapy for severe hemodynamic or respiratory failure. Nosocomial infections on ECMO support are frequent (infection rate ranging between 20.5% to more than 50% of ECMO runs) and have impact in survival, with reported increases in the risk of death up to 63% in infected patients. However, diagnosis and treatment are challenging, as the unique relationship between patient and circuit may act as a confounder for infection and exacerbate the variability of antibiotic pharmacokinetics in critical illness. Clinical practice regarding antibiotic treatment and infection prevention is not yet supported by high-quality evidence.

Bloodstream and respiratory coinfections in patients with COVID-19 on ECMO

BACKGROUND

Although several studies have characterized the risk of coinfection in COVID pneumonia, the risk of the bloodstream and respiratory coinfection in patients with COVID-19 pneumonia on extracorporeal membrane oxygenation (ECMO) supports severe acute respiratory distress syndrome (ARDS) is poorly understood.

METHODS

This is a retrospective analysis of patients with COVID-19 ARDS on ECMO at a single center between January 2020 and December 2021. Patient characteristics and clinical outcomes were compared.

RESULTS

Of 44 patients placed on ECMO support for COVID-19 ARDS, 30 (68.2%) patients developed a coinfection, and 14 (31.8%) patients did not. Most patients underwent venovenous ECMO (98%; 43/44) cannulation in the right internal jugular vein (98%; 43/44). Patients with coinfection had a longer duration of ECMO (34 [interquartile range, IQR: 19.5, 65] vs. 15.5 [IQR 11, 27.3] days; p = .02), intensive care unit (ICU; 44 [IQR: 27,75.5] vs 31 [IQR 20-39.5] days; p = .03), and hospital (56.5 [IQR 27,75.5] vs 37.5 [IQR: 20.5-43.3]; p = .02) length of stay. When stratified by the presence of a coinfection, there was no difference in hospital mortality (37% vs. 29%; p = .46) or Kaplan-Meier survival (logrank p = .82). Time from ECMO to first positive blood and respiratory culture were 12 [IQR: 3, 28] and 10 [IQR: 1, 15] days, respectively. Freedom from any coinfection was 50 (95% confidence interval: 37.2-67.2)% at 15 days from ECMO initiation.

CONCLUSIONS

There is a high rate of co-infections in patients placed on ECMO for COVID-19 ARDS. Although patients with coinfections had a longer duration of extracorporeal life support, and longer length of stays in the ICU and hospital, survival was not inferior.

Clinical and microbiological characteristics of and risk factors for bloodstream infections among patients with extracorporeal membrane oxygenation: a single-center retrospective cohort study

Extracorporeal membrane oxygenation (ECMO) provides hemodynamic and oxygenation support to critically ill patients. Due to multiple catheter cannulations, patients on ECMO are vulnerable to bloodstream infections (BSIs). We aimed to investigate the incidence, clinical characteristics, risk factors, and microorganisms associated with BSIs during ECMO. This single-center retrospective cohort study was conducted between January 2015 and May 2021. Patients aged 18 years or older with an ECMO duration of > 48 h for cardiogenic or respiratory support were included in the study. Patients who developed bacteremia or candidemia from 12 h after ECMO cannulation to 7 days after de-cannulation were included. The clinical factors between non-BSI and BSI were compared, along with an analysis of the risk factors associated with BSI during ECMO. A total of 480 patients underwent ECMO for cardiogenic shock (n = 267, 55.6%) or respiratory failure (n = 213, 44.4%) during the study period. The incidence was 20.0 episodes per 1000 ECMO-days. Approximately 20.2% (97/480) and 5.4% (26/480) of the patients developed bacteremia and candidemia, respectively. The median numbers of days of BSI development were 8.00 days for bacteremia and 11.0 days for candidemia. The most common pathogens were methicillin-resistant coagulase-negative staphylococci (n = 24), followed by vancomycin-resistant Enterococcus (n = 21). Multivariable logistic analysis demonstrated that hemodialysis (odds ratio [OR] 2.647, p < 0.001), veno-arterial-venous mode (OR 1.911, p = 0.030), and total ECMO duration (OR 1.030, p = 0.007) were significant risk factors for bacteremia. The total ECMO duration was the only risk factor associated with candidemia (OR 1.035, p = 0.010). The mortality rate was significantly higher in the bacteremia (57.7%) and candidemia (69.2%) groups than that in the non-BSI group (43.6%). BSI is a common complication of patients receiving ECMO support and is associated with poor clinical outcomes. Determining the type of frequently isolated organisms and the median onset time of BSI would help in the selection of appropriate prophylactic antibiotics or antifungal agents.

Nosocomial Infections in Nonsurgical Patients Undergoing Extracorporeal Membrane Oxygenation: A Retrospective Analysis in a Chinese Hospital

Background

The effect of nosocomial infections (NIs) in adult patients undergoing ECMO has been rarely reported in China. Moreover, the effect of NIs on ECMO patients’ mortality is still unclear and inconclusive according to literature data. In this study, we examined the prevalence, risk factors, causative organisms, and effects on outcomes of NIs in ECMO patients.

Methods

A total of 79 nonsurgical patients (mean age 53.3±15.2 year (yr); 66% male) who underwent ECMO between January 2011 and September 2020 were enrolled in this retrospective study. Patients’ demographic and clinical data and ECMO parameters were collected from all patients.

Results

Among 79 patients who underwent ECMO for a total of 1253 ECMO days (mean time 15.9±14.1 d), 42 developed NIs. We observed 30 ventilator-associated pneumonia (VAP), 19 bloodstream infections (BSIs), and 4 urinary tract infections, corresponding to 23.9/1000 ECMO days, 15.2/1000 ECMO days, and 3.2/1000 ECMO days, respectively. ECMO duration (22.0±16.5 VS 8.9±5.3 d, P < 0.001), invasive mechanical ventilation (IMV) duration (27.4±20.5 VS 11.4±10.1 d, P < 0001), and ICU length of stay (35.9±22.9 VS 15.7±9.2 d, P < 0.001) were longer in patients with NIs. The independent risk factors for NIs were ECMO duration (Odds Ratio [OR], 1.414; 95% Confidence Interval [CI], (1.051–1.238); P = 0.002) and viral pneumonia (OR, 5.788; 95% CI, (1.551–21.596); P = 0.009). Gram-negative bacteria were the most common causative organisms of NIs; Acinetobacter baumannii (A. baumannii), Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) were the most common bacteria. BSI (OR, 8.106; 95% CI, (1.384–47.474); P = 0.02) was an independent predictor for mortality.

Conclusion

NIs are common complications in patients during ECMO treatment, especially VAP, followed by BSI. Also, BSI can negatively affect the survival rate.

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.

Indwelling Central Venous Catheters Drive Bloodstream Infection During Veno-venous Extracorporeal Membrane Oxygenation Support

Blood stream infection (BSI) is a potentially lethal complication in patients receiving extracorporeal membrane oxygenation (ECMO). It may be particularly common in patients with veno-venous ECMO due to their long hospitalization in the intensive care unit. Given that these patients have concurrent indwelling central venous catheters (CVC), it is unclear whether the ECMO circuit, CVC, or both, contribute to BSI. This study evaluated the risk factors associated with BSI in patients receiving veno-venous ECMO in a single institution study of 61 patients from 2016 through 2019. All ECMO catheters and the circuit oxygenator fluid were aseptically collected and analyzed for microorganisms at the time of decannulation. New BSI was diagnosed in 15 (24.6%) patients and increased mortality by threefold. None of the ECMO catheters or oxygenator fluid were culture positive. BSI increased with CVC use of over 8 days and was significantly lowered when CVC were exchanged by day 8 compared with patients with exchanges at later points (15.0% vs. 42.8%, p = 0.02). Median length of CVC use in the BSI-negative and BSI-positive group were 6.3 ± 5.0 and 9.4 ± 5.1, respectively (p = 0.04). In summary, BSI is a potentially lethal complication in patients receiving ECMO. Indwelling CVC, not the ECMO circuitry, is the likely contributor for BSI, and exchanging CVC by day 8 can reduce the incidence of BSI.

Peri-Operative Prophylaxis in Patients of Neonatal and Pediatric Age Subjected to Cardiac and Thoracic Surgery: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs) represent a potential complication of surgical procedures, with a significant impact on mortality, morbidity, and healthcare costs. Patients undergoing cardiac surgery and thoracic surgery are often considered patients at high risk of developing SSIs. This consensus document aims to provide information on the management of peri-operative antibiotic prophylaxis for the pediatric and neonatal population undergoing cardiac and non-cardiac thoracic surgery. The following scenarios were considered: (1) cardiac surgery for the correction of congenital heart disease and/or valve surgery; (2) cardiac catheterization without the placement of prosthetic material; (3) cardiac catheterization with the placement of prosthetic material; (4) implantable cardiac defibrillator or epicardial pacemaker placement; (5) patients undergoing ExtraCorporal Membrane Oxygenation; (6) cardiac tumors and heart transplantation; (7) non-cardiac thoracic surgery with thoracotomy; (8) non-cardiac thoracic surgery using video-assisted thoracoscopy; (9) elective chest drain placement in the pediatric patient; (10) elective chest drain placement in the newborn; (11) thoracic drain placement in the trauma setting. This consensus provides clear and shared indications, representing the most complete and up-to-date collection of practice recommendations in pediatric cardiac and thoracic surgery, in order to guide physicians in the management of the patient, standardizing approaches and avoiding the abuse and misuse of antibiotics.

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

OBJECTIVE

To assess the incidence and significance of invasive fungal diseases (IFD) during veno-venous (VV) ECMO support for acute respiratory distress syndrome (ARDS).

METHODS

Retrospective analysis from January 2013 to April 2021 of all ECMO cases for ARDS at a German University Hospital. In patients with IFD (IFD patients), type of IFD, time of IFD, choice of antifungal agent, duration, and success of therapy were investigated. For comparison, patients without IFD (non-IFD patients) were selected by propensity score matching using treatment-independent variables (age, gender, height, weight, and the Sequential Organ Failure Assessment (SOFA) score at ICU admission). Demographics, hospital and ICU length of stay, duration of ECMO therapy, days on mechanical ventilation, prognostic scores (Charlson Comorbidity Index (CCI), Therapeutic Intervention Scoring System (TISS), and length of survival were assessed.

RESULTS

A total of 646 patients received ECMO, 368 patients received VV ECMO. The incidence of IFD on VV ECMO was 5.98%, with 5.43% for Candida bloodstream infections (CBSI) and 0.54% for invasive aspergillosis (IA). In IFD patients, in-hospital mortality was 81.8% versus 40.9% in non-IFD patients. The hazard ratio for death was 2.5 (CI 1.1-5.4; p: 0.023) with IFD.

CONCLUSIONS

In patients on VV ECMO for ARDS, about one in 17 contracts an IFD, with a detrimental impact on prognosis. Further studies are needed to address challenges in the diagnosis and treatment of IFD in this population.

Biofilm microbiome in extracorporeal membrane oxygenator catheters

Despite the formation of biofilms on catheters for extracorporeal membrane oxygenation (ECMO), some patients do not show bacteremia. To elucidate the specific linkage between biofilms and bacteremia in patients with ECMO, an improved understanding of the microbial community within catheter biofilms is necessary. Hence, we aimed to evaluate the biofilm microbiome of ECMO catheters from adults with (n = 6) and without (n = 15) bacteremia. The microbiomes of the catheter biofilms were evaluated by profiling the V3 and V4 regions of bacterial 16s rRNA genes using the Illumina MiSeq sequencing platform. In total, 2,548,172 reads, with an average of 121,341 reads per sample, were generated. Although alpha diversity was slightly higher in the non-bacteremic group, the difference was not statistically significant. In addition, there was no difference in beta diversity between the two groups. We found 367 different genera, of which 8 were present in all samples regardless of group; Limnohabitans, Flavobacterium, Delftia, Massilia, Bacillus, Candidatus, Xiphinematobacter, and CL0-1 showed an abundance of more than 1% in the sample. In particular, Arthrobacter, SMB53, Neisseria, Ortrobactrum, Candidatus Rhabdochlamydia, Deefgae, Dyella, Paracoccus, and Pedobacter were highly abundant in the bacteremic group. Network analysis indicated that the microbiome of the bacteremic group was more complex than that of the non-bacteremic group. Flavobacterium and CL0.1, which were abundant in the bacteremic group, were considered important genera because they connected different subnetworks. Biofilm characteristics in ECMO catheters varied according to the presence or absence of bacteremia. There were no significant differences in diversity between the two groups, but there were significant differences in the community composition of the biofilms. The biofilm-associated community was dynamic, with the bacteremic group showing very complex network connections within the microbiome.

Extracorporeal membrane oxygenation combined with continuous renal replacement therapy for the treatment of severe burns: current status and challenges

Severe burns often cause various systemic complications and multiple organ dysfunction syndrome, which is the main cause of death. The lungs and kidneys are vulnerable organs in patients with multiple organ dysfunction syndrome after burns. Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) have been gradually applied in clinical practice and are beneficial for severe burn patients with refractory respiratory failure or renal dysfunction. However, the literature on ECMO combined with CRRT for the treatment of severe burns is limited. Here, we focus on the current status of ECMO combined with CRRT for the treatment of severe burns and the associated challenges, including the timing of treatment, nutrition support, heparinization and wound management, catheter-related infection and drug dosing in CRRT. With the advancement of medical technology, ECMO combined with CRRT will be further optimized to improve the outcomes of patients with severe burns.

Prognosis After Weaning from Respiratory Extracorporeal Membrane Oxygenation

Successful weaning from extracorporeal membrane oxygenation (ECMO) does not necessarily imply patient survival. We retrospectively analyzed 441 patients with acute respiratory failure from 16 hospitals in South Korea who underwent ECMO from January 2012 to December 2015. We evaluated the clinical factors associated with mortality after successful weaning from ECMO. Of all 441 patients, 245 (55.6%) were successfully weaned from ECMO. The majority of patients were initially supported with veno-venous ECMO (86.9%). Among those, 182 patients (41.3%) were discharged from hospital. Only 165 (37.4%) were alive after 6 months. Most cases of death occurred within the first month after weaning from ECMO (65%), and the most frequent reason for death was sepsis (76.2%). In the multivariate Cox regression analysis, patient age (per 10 years) (hazard ratio [HR] = 1.34, 95% CI = 1.12-1.61; p = 0.001), sequential organ failure assessment score (HR = 1.07, 95% CI = 1.02-1.13; p = 0.010), steroid (HR = 2.38, 95% CI = 1.27-4.45; p = 0.007), interstitial lung disease (HR = 1.20, 95% CI = 1.05-1.36; p = 0.006), and ECMO duration (per day) (HR = 1.02, 95% CI = 1.01-1.04; p < 0.001) were associated with the in-hospital mortality after weaning from ECMO. Furthermore, age (per 10 years) (HR = 1.45, 95% CI = 1.24-1.71; p < 0.001), steroid (HR = 2.19, 95% CI = 1.27-3.78; p = 0.005), and interstitial lung disease (HR = 1.16, 95% CI = 1.02-1.31; p = 0.021) were significantly associated with 6 month mortality. The prognosis after weaning from respiratory ECMO might be related to baseline conditions affecting the reversibility of the primary lung disease and to acquired infections.

Microbial Colonization of Oxygenator and Clinical Outcomes in Extracorporeal Membrane Oxygenation

The importance of microbial colonization during extracorporeal membrane oxygenation (ECMO) is unclear. We prospectively cultured ECMO oxygenators and retrospectively reviewed the culture results, clinical outcomes, and associated factors in 112 ECMO patients (122 oxygenators, 1,196 ECMO days). Of the oxygenators, 11.6% (n = 13) had positive cultures. The most common pathogen was Klebsiella pneumoniae, followed by Acinetobacter baumannii and Staphylococcus epidermidis. Nine (69%) cases showed catheter colonization, and five (38%) bloodstream infection (BSI) with the same microorganism. Most of the microorganisms were multidrug resistant. BSI tended to be associated with oxygenator colonization (r = 0.172, p = 0.070). The patients were divided into oxygenator colonization (n = 13) and no colonization groups (n = 99). Successful weaning from ECMO and survival to discharge were significantly lower in the oxygenator colonization group (weaning 30.8% vs. 90.9%, p < 0.001, survival 23.1% vs. 76.8%; p < 0.001). In multivariate analyses, age (per decade) (odds ratio [OR] = 1.95, 95% CI = 1.28-2.95; p = 0.002), oxygenator colonization (OR = 15.49, 95% CI = 3.31-72.46; p < 0.001), and renal replacement therapy (OR = 4.61, 95% CI = 1.69-12.58; p = 0.003) were significantly associated with mortality. Oxygenator colonization was associated with poor outcomes in ECMO patients. These results support the early exchange and culture of oxygenators in patients with persisting bacteremia.

Epidemiology and Clinical Characteristics of Bloodstream Infection in Patients Under Extracorporeal Membranous Oxygenation

BACKGROUND

Bloodstream infection (BSI) is an important complication of extracorporeal membranous oxygenation (ECMO) and a major cause of mortality. This study evaluated the epidemiological and clinical characteristics of BSI that occur during ECMO application according to microbial etiology.

METHODS

Adult patients who underwent ECMO from January 2009 to December 2016 were retrospectively analyzed for BSI episodes at a 2,700-bed, tertiary center. Epidemiological and clinical characteristics and outcomes of BSI were evaluated and were compared for etiologic groups (gram-positive cocci, gram-negative rods, and fungi groups). Risk factors for 14-day mortality were analyzed.

RESULTS

A total of 1,100 patients underwent ECMO during the study period, and 65 BSI episodes occurred in 61 patients. The BSI incidence was 8.3 episodes/1,000 ECMO days, which significantly decreased over time (P = 0.03), primarily in gram-positive cocci BSI. Gram-positive cocci, gram-negative rods, and fungi accounted for 38%, 40%, and 22% of the 73 blood isolates, respectively. Baseline characteristics were comparable between groups. Catheter-related infection (CRI) and pneumonia were the most common sources of BSI; 52% of gram-positive cocci BSIs and 79% of fungi BSIs were caused by CRI, and 75% of gram-negative BSIs by pneumonia. Patients with gram-negative rods BSI died more frequently and earlier than those with other BSIs. Independent risk factors for 14-day mortality were older age and gram-negative rods BSI.

CONCLUSIONS

The decreased BSI incidence during ECMO was mainly because of the decrease of gram-positive cocci BSI. The high early mortality of gram-negative rods BSI makes prevention and adequate treatment necessary.

A Retrospective Study of Infection in Patients Requiring Extracorporeal Membrane Oxygenation Support

BACKGROUND

Healthcare-associated infections (HAIs) in critically ill patients are a serious public health problem. Extracorporeal membrane oxygenation (ECMO) has been used increasingly for patients with severe cardiac or respiratory failure, but it may increase HAI risk. The goal of our study was to characterize HAIs in ECMO patients at an ECMO referral center.

METHODS

This institutional review board-approved study identified all consecutive adult ECMO patients admitted to the cardiac surgery intensive care unit (CSICU) between January 1, 2015, and December 31, 2017. Demographic data, diagnosis, ECMO cannulation technique, and survival were collected. Urinary tract infection, pneumonia, and bacteremia incidence during ECMO and within 3 months of decannulation were collected. Outcomes of patients with HAIs were compared with noninfected patients, the CSICU infection incidence, and overall Extracorporeal Life Support Organization survival data.

RESULTS

There were 288 ECMO patients and 3396 CSICU admissions during this period. Survival was 72.3% for venoarterial ECMO, 85.3% for venovenous ECMO, and 57.1% for multimodality or veno-arteriovenous ECMO, with discharge survival of 60.2%, 72.0%, and 28.6%, respectively. Bacteremia incidence while cannulated was 6.8% for venoarterial ECMO and 9.3% for venovenous ECMO. Bacteremia occurred in 22 of 288 (7.6%) ECMO patients, compared with 48 of 3109 (1.5%) in non-ECMO CSICU patients, which was statistically significant (P < .002). Bacteremia and pneumonia were associated with decreased VA-ECMO survival, with prolonged overall requirements for ECMO support.

CONCLUSIONS

Nosocomial ECMO infections are significantly higher than in other CSICU patients. Infection risk remains significant even after decannulation. Infection is associated with increased mortality and longer duration of ECMO support. Further efforts are needed to determine HAI reduction strategies in this high-risk patient population.

Duration of Venoarterial Extracorporeal Membrane Oxygenation and Mortality in Postcardiotomy Cardiogenic Shock

OBJECTIVE

The optimal duration of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients affected by postcardiotomy cardiogenic shock (PCS) remains controversial. The present study was conducted to investigate the effect of VA-ECMO duration on hospital outcomes.

DESIGN

Retrospective analysis of an international registry.

SETTING

Multicenter study including 19 tertiary university hospitals.

PARTICIPANTS

Between January 2010 and March 2018, data on PCS patients receiving VA-ECMO were retrieved from the multicenter PC-ECMO registry.

INTERVENTIONS

Patients were stratified according to the following different durations of VA-ECMO therapy: ≤three days, four-to-seven days, eight-to-ten days, and >ten days.

MEASUREMENTS AND MAIN RESULTS

A total of 725 patients, with a mean age of 62.9 ± 12.9 years, were included. The mean duration of VA-ECMO was 7.1 ± 6.3 days (range 0-39 d), and 39.4% of patients were supported for ≤three days, 29.1% for four-seven days, 15.3% for eight-ten days, and finally 20.7% for >ten days. A total of 391 (53.9%) patients were weaned from VA-ECMO successfully; however, 134 (34.3%) of those patients died before discharge. Multivariate logistic regression showed that prolonged duration of VA-ECMO therapy (four-seven days: adjusted rate 53.6%, odds ratio [OR] 0.28, 95% confidence interval [CI] 0.18-0.44; eight-ten days: adjusted rate 61.3%, OR 0.51, 95% CI 0.29-0.87; and >ten days: adjusted rate 59.3%, OR 0.49, 95% CI 0.31-0.81) was associated with lower risk of mortality compared with VA-ECMO lasting ≤three days (adjusted rate 78.3%). Patients requiring VA-ECMO therapy for eight-ten days (OR 1.96, 95% CI 1.15-3.33) and >10 days (OR 1.85, 95% CI 1.14-3.02) had significantly greater mortality compared with those on VA-ECMO for 4 to 7 days.

CONCLUSIONS

PCS patients weaned from VA-ECMO after four-seven days of support had significantly less mortality compared with those with shorter or longer mechanical support.

Chlorhexidine bathing of the exposed circuits in extracorporeal membrane oxygenation: an uncontrolled before-and-after study

BACKGROUND

Although the prevention of extracorporeal membrane oxygenation (ECMO) catheter-related infection is crucial, scientific evidence regarding best practices are still lacking.

METHODS

We conducted an uncontrolled before-and-after study to test whether the introduction of disinfection with 2% chlorhexidine gluconate (CHG) and 70% isopropyl alcohol (IPA) of the exposed circuits and hub in patients treated with ECMO would affect the rate of blood stream infection (BSI) and microbial colonization of the ECMO catheter. We compared the microbiological and clinical data before and after the intervention.

RESULTS

A total of 1740 ECMO catheter days in 192 patients were studied. These were divided into 855 ECMO catheter days in 96 patients before and 885 ECMO catheter days in 96 patients during the intervention. The rates of BSI were significantly decreased during the intervention period at 11.7/1000 ECMO catheter days before vs. 2.3/1000 ECMO catheter days during (difference 9.4, 95% confidence interval (CI) 1.5-17.3, p = 0.019). Furthermore, the colonization of the ECMO catheter was similarly significantly reduced during the intervention period at 10.5/1000 ECMO catheter days before vs. 2.3/1000 ECMO catheter days during intervention (difference 8.3, 95% CI 0.7-15.8, p = 0.032). Hospital mortality (41.7% vs. 24%, p = 0.009) and sepsis-related death (17.7% vs. 6.3%, p = 0.014) were also significantly decreased during intervention.

CONCLUSION

Extensive disinfection of exposed ECMO circuits and hub with 2% CHG/IPA was associated with a reduction in both BSI and microbial colonization of ECMO catheters. A further randomized controlled study is required to verify these results.

TRIAL REGISTRATION

KCT 0004431.

A Systematic Review of Preexisting Sepsis and Extracorporeal Membrane Oxygenation

We retrospectively reviewed all pertinent extracorporeal membrane oxygenation (ECMO) studies (January 1995 to September 2017) of adults with sepsis as a primary indication for intervention and its association with morbidity and mortality. Collected data included study type, ECMO configuration, outcomes, effect size, and other features. Advanced age was a risk factor for death. Compared with nonsurvivors, survivors had a lower median Sepsis-Related Organ Failure Assessment score on day 3 (15 vs. 18, p = 0.01). Biomarkers in survivors and nonsurvivors, respectively, were peak lactate (from two studies: 4.5 vs. 15.1 mmol/L, p = 0.03; 3.6 ± 3.7 vs. 3.3 ± 2.4 mmol/L, p = 0.850) and procalcitonin levels (41 vs. 164 ng/ml, p = 0.008). Bacteremia was associated with catheter colonization, and 90.5% of a group without bloodstream infections survived to discharge; ECMO weaning was possible for less than half the bloodstream infection group. Myocarditis portended favorable outcomes for patients with sepsis who received ECMO. Extracorporeal membrane oxygenation was used in immunosuppressed patients with refractory cardiopulmonary insufficiency from severe sepsis with successful weaning from ECMO for most patients. Overall survival varied substantially among studies (15.38-71.43%). Existing studies do not present well-defined patterns supporting use of ECMO in sepsis because of sample sizes and disparate study designs.

Incidence of healthcare-associated infections in patients with fever during the first 48 hours after decannulation from veno-venous extracorporeal membrane oxygenation

INTRODUCTION

Fevers following decannulation from veno-venous extracorporeal membrane oxygenation often trigger an infectious workup; however, the yield of this workup is unknown. We investigated the incidence of post-veno-venous extracorporeal membrane oxygenation decannulation fever as well as the incidence and nature of healthcare-associated infections in this population within 48 hours of decannulation.

METHODS

All patients treated with veno-venous extracorporeal membrane oxygenation for acute respiratory failure who survived to decannulation between August 2014 and November 2018 were retrospectively reviewed. Trauma patients and bridge to lung transplant patients were excluded. The highest temperature and maximum white blood cell count in the 24 hours preceding and the 48 hours following decannulation were obtained. All culture data obtained in the 48 hours following decannulation were reviewed. Healthcare-associated infections included blood stream infections, ventilator-associated pneumonia, and urinary tract infections.

RESULTS

A total of 143 patients survived to decannulation from veno-venous extracorporeal membrane oxygenation and were included in the study. In total, 73 patients (51%) were febrile in the 48 hours following decannulation. Among this cohort, seven healthcare-associated infections were found, including five urinary tract infections, one blood stream infection, and one ventilator-associated pneumonia. In the afebrile cohort (70 patients), four healthcare-associated infections were found, including one catheter-associated urinary tract infection, two blood stream infections, and one ventilator-associated pneumonia. In all decannulated patients, the majority of healthcare-associated infections were urinary tract infections (55%). No central line-associated blood stream infections were identified in either cohort. When comparing febrile to non-febrile cohorts, there was a significant difference between pre- and post-decannulation highest temperature (p < 0.001) but not maximum white blood cell count (p = 0.66 and p = 0.714) between the two groups. Among all positive culture data, the most commonly isolated organism was Klebsiella pneumoniae (41.7%) followed by Escherichia coli (33%). Median hospital length of stay and time on extracorporeal membrane oxygenation were shorter in the afebrile group compared to the febrile group; however, this did not reach a statistical difference.

CONCLUSION

Fever is common in the 48 hours following decannulation from veno-venous extracorporeal membrane oxygenation. Differentiating infection from non-infectious fever in the post-decannulation veno-venous extracorporeal membrane oxygenation population remains challenging. In our febrile post-decannulation cohort, the incidence of healthcare-associated infections was low. The majority were diagnosed with a urinary tract infection. We believe obtaining cultures in febrile patients in the immediate decannulation period from veno-venous extracorporeal membrane oxygenation has utility, and even in the absence of other clinical suspicion, should be considered. However, based on our data, a urinalysis and urine culture may be sufficient as an initial work up to identify the source of infection.

Risk factors for complete recovery of adults after weaning from veno-venous extracorporeal membrane oxygenation for severe acute respiratory failure: an analysis from adult patients in the Extracorporeal Life Support Organization registry

BACKGROUND

As extracorporeal membrane oxygenation (ECMO) has been widely used, the patient quality of life following ECMO termination has become an important issue as same as the patient's survival. To date, the factors affecting complete recovery of adult survivors from ECMO have not been investigated.

METHODS

Data from adult patients in the Extracorporeal Life Support Organization registry who received veno-venous ECMO between 2012 and 2017 were analyzed. Multivariate logistic regression analyses were conducted.

RESULTS

In total, 6536 patients with 242,183 days of veno-venous ECMO were reviewed. The overall survival to discharge rate after weaning from ECMO was 89.7% (n = 5861), and 10.3% (n = 675) of the patients died during hospitalization. The discharge location varied as follows: 33.7% (n = 1976) returned home, 23.4% (n = 1369) were transferred to a referral hospital, 41.8% (n = 2447) required hospital services, and 0.6% (n = 36) were discharged to other places. The patients were divided into two groups according to the discharge location: a complete recovery group (n = 1976) and a partial recovery group (n = 3885). In the multivariate analyses, age (≥ 65 years) (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.59-0.87, p = 0.001), cardiac arrest before ECMO (OR 0.76, 95% CI 0.60-0.96, p = 0.021), vasopressor use (OR 0.73, 95% CI 0.64-0.83, p < 0.001), renal replacement therapy (OR 0.40, 95% CI 0.28-0.57, p < 0.001), ECMO-related complications (OR 0.76, 95% CI 0.67-0.85, p < 0.001), and long-term ECMO support (≥ 2 weeks) (OR 0.42, 95% CI 0.37-0.48, p < 0.001) were significantly associated with complete recovery.

CONCLUSION

Complete recovery after veno-venous ECMO support is associated with the patient's baseline condition, ECMO duration, and ECMO-related complications. Respiratory ECMO should aim to increase both the survival and the quality of life after weaning from ECMO.

Catheter-related bloodstream infections in a nephrology unit: Analysis of patient- and catheter-associated risk factors

BACKGROUND

Central venous catheter use is rising in chronic and acute hemodialysis. Catheter-related bloodstream infections are a major complication of central venous catheter use. This article examines clinical factors associated with catheter-related bloodstream infections incidence.

METHODS

In this retrospective, single-center study, 413 patients undergoing extracorporeal treatments between 1 February 2014 and 31 January 2017 with 560 central venous catheters were recruited. Clinical parameters, such as gender, age, kidney disease status, diabetes, immunosuppression, and vintage dialysis, were collected at study entry. An incidence rate ratio (95% confidence interval) was calculated to assess the association between catheter-related bloodstream infections incidence rate and each clinical variable/central venous catheter type. Significant associations at the univariate analyses were investigated with multivariate Cox models.

RESULTS

During a cumulative time of 66,686 catheter-days, 54 catheter-related bloodstream infections (incidence rate: 0.81) events occurred. Gram negative bacteria were more frequent in patients with age < 80 years (16 (36%) vs. 0, p = 0.02). At the univariate analyses, male sex (incidence rate ratio: 1.9 (1.1-3.5), p = 0.03), age < 80 years (incidence rate ratio: 2.4 (1.1-5.5), p = 0.016) and acute kidney injury (incidence rate ratio: 5.6 (3.1-10), p < 0.0001) were associated with higher catheter-related bloodstream infections incidence rate. Compared with tunneled jugular central venous catheter, higher catheter-related bloodstream infections incidence rate was associated with non-tunneled jugular (incidence rate ratio: 6.45 (2.99-13.56), p < 0.0001) and non-tunneled femoral (incidence rate ratio: 12.90 (5.87-27.61), p < 0.0001) central venous catheter use; tunneled femoral central venous catheter was associated with higher non-significant incidence rate (incidence rate ratio: 2.45 (0.93-5.85), p = 0.07). The multivariate analyses showed that acute kidney injury (hazard ratio: 3.03 (1.38-6.67), p = 0.006), non-tunneled (hazard ratio: 3.11 (1.30-7.41), p = 0.01) and femoral (hazard ratio: 2.63 (1.36-5.07), p = 0.004) central venous catheter were associated with higher catheter-related bloodstream infections incidence rate.

CONCLUSION

Central venous catheter characteristics and acute kidney injury are independently associated with higher catheter-related bloodstream infections rate.

Clinical outcomes according to cannula configurations in patients with acute respiratory distress syndrome under veno-venous extracorporeal membrane oxygenation: a Korean multicenter study

BACKGROUND

Recirculation during veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a known drawback that limits sufficient oxygenation. This study aimed to compare the short-term oxygenation and long-term mortality based on cannula configuration in patients with acute respiratory distress syndrome (ARDS) who receive VV-ECMO, especially in the absence of newly developed dual-lumen, single cannula.

METHODS

Data of patients with severe ARDS who received VV-ECMO from 2012 to 2015 at six hospitals were retrospectively analyzed. Primary outcomes were the partial pressure of oxygen (PaO₂) at 1, 4, and 12 h after ECMO initiation and 180-day mortality.

RESULTS

Patients (n = 335) were divided into two groups based on the return cannula site: femoral vein (n = 178) or internal jugular vein (n = 157). The propensity score matching analysis generated 90 pairs, and baseline characteristics at admission, including PaO₂, were similar between the groups. PaO₂ at 1, 4 and 12 h after ECMO initiation were not different according to cannula configuration. Moreover, the increment in oxygenation from the baseline values was not different between the femoral and jugular group. PaCO₂ level at 1, 4 and 12 h were significantly lower in the jugular group. The two groups did not differ in terms of mortality at 180 days after ECMO, however more cannula-related complications occurred in the jugular group.

CONCLUSION

Regardless of the cannula configuration, patients with ARDS managed with VV-ECMO showed comparable clinical outcomes in terms of short-term oxygenation and long-term mortality. Nevertheless, further well-designed randomized control trials are warranted.

Pharmacokinetic Assessment of Pre- and Post-Oxygenator Vancomycin Concentrations in Extracorporeal Membrane Oxygenation: A Prospective Observational Study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary life support frequently utilized in catastrophic lung and or cardiac failure. Patients on ECMO often receive vancomycin therapy for treatment or prophylaxis against Gram-positive organisms. It is unclear if ECMO affects vancomycin pharmacokinetics, thus we modeled the pharmacokinetic behavior of vancomycin according to ECMO-specific variables.

METHODS

Adult patients receiving vancomycin and Veno-Arterial-ECMO between 12/1/2016 and 10/1/2017 were prospectively enrolled. Extracorporeal membrane oxygenation settings and four sets of pre- and post-oxygenator vancomycin concentrations were collected for each patient. Compartmental models were built and assessed ECMO flow rates on vancomycin clearance and potential circuit sequestration. Bayesian posterior concentrations of the pre- and post-oxygenator concentrations were obtained for each patient, and summary pharmacokinetic parameters were calculated. Simulations were performed from the final model for efficacy and toxicity predictions.

RESULTS

Eight patients contributed 64 serum concentrations. Patients were a median (interquartile range) age of 58.5 years (50.8-62.3) with a calculated creatinine clearance of 39 mL/min (29.5-62.5) and ECMO flow rates of 3980 mL/min (interquartile range = 3493.75-4132.5). A three-compartment model best fit the data (Bayesian: plasma pre-oxygenation R² = 0.99, post-oxygenation R² = 0.99). Vancomycin clearance was not impacted by ECMO flow rate (p = 0.7). Simulations demonstrated that vancomycin 1 g twice daily was rarely sufficient for minimum inhibitory concentrations > 0.5 mg/L. Doses ≥ 1.5 g twice daily often exceeded toxicity thresholds for exposure.

CONCLUSIONS

Extracorporeal membrane oxygenation flow rates did not influence vancomycin clearance between flow rates of 3500 and 5000 mL/min and vancomycin was not sequestered in ECMO. Common vancomycin regimens resulted in suboptimal efficacy and/or excessive toxicity. Individual therapeutic drug monitoring is recommended for patients on 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.

Learning curve for multidisciplinary team setup in veno-venous extracorporeal membrane oxygenation for acute respiratory failure

BACKGROUND

Quality control is essential for a successful extracorporeal membrane oxygenation program. We investigated the learning curve for outcome improvement and focused on factors associated with failure of extracorporeal membrane oxygenation treatment.

METHODS

Between August 2011 and May 2017, 150 patients were supported with veno-venous extracorporeal membrane oxygenation for acute respiratory failure. The learning curve was examined using cumulative sum analysis. We defined successful extracorporeal membrane oxygenation treatment as intensive care unit discharge, acceptable failure rate as 40%, and unacceptable failure rate as 60%. We chronologically divided patients into three periods with 50 consecutive patients each and retrospectively compared the clinical outcomes by period.

RESULTS

Overall, weaning and survival to discharge rates were 72.7% and 56%, respectively. Cumulative sum analysis indicated that the extracorporeal membrane oxygenation team achieved nearly acceptable performance after 56 cases and consistently acceptable performance after 104 cases. Clinical outcomes were improved by period: weaning rate (58% vs. 80% vs. 80%, p = 0.017); intensive care unit discharge rate (42% vs. 60% vs. 78%, p = 0.001); survival to discharge rate (40% vs. 58% vs. 70%, p = 0.010); and 1 year survival rate (40% vs. 56% vs. 70%, p = 0.010). In multivariate analysis, infection (odds ratio: 4.54, 95% confidence interval: 1.83-11.27, p = 0.001), immune compromise (odds ratio: 5.78, 95% confidence interval: 1.66-20.14, p = 0.006), extracorporeal membrane oxygenation team period (odds ratio: 2.12, 95% confidence interval: 1.14-3.92, p = 0.017), and age (odds ratio: 1.09, 95% confidence interval: 1.05-1.14, p < 0.001) were associated with extracorporeal membrane oxygenation failure.

CONCLUSION

More than 100 cases of extracorporeal membrane oxygenation experience were necessary for acceptable performance and stabilization of outcomes.

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.

Bacterial Biofilms on Extracorporeal Membrane Oxygenation Catheters

Despite the advantages of extracorporeal membrane oxygenation (ECMO), secondary catheter infection remains a major concern during ECMO support. In this study, to clarify the mechanism of ECMO catheter-related infection, we evaluated the impact of infection on biofilm formation on the surfaces of ECMO catheters, and we investigated clinical factors associated with biofilm formation. Catheters used for ECMO were prospectively collected aseptically from the femoral vein, internal jugular vein, and femoral artery of 81 patients with acute cardiorespiratory failure between January 2015 and October 2016. Prepared catheter sections were investigated by fluorescence microscopy, confocal scanning laser microscopy, transmission electron microscopy, and using semiquantitative culture methods. Of the 81 patients, 51 were assigned to the infection group and 30 to a control group. Biofilms were identified in 43.1% patients in the infection group, and in 20% controls (p = 0.034). Extracorporeal membrane oxygenation flow, systemic infection, and carbapenem-resistant Acinetobacter baumannii (CRAB) infection were associated with biofilm formation in a univariate analysis (odds ratio [OR]: 1.00, 95% confidence interval [CI]: 1.00-1.00, p = 0.007; OR: 3.03, 95% CI: 1.06-8.69, p = 0.039; OR: 9.60, 95% CI: 2.94-31.30, p < 0.001, respectively). However, of these factors, only CRAB infection was found to independently predict the presence of a biofilm by a multivariate logistic regression analysis (OR: 9.60, 95% CI: 2.94-31.30; p < 0.001). Biofilms were more prevalent in patients with an infection than in uninfected controls. Carbapenem-resistant A. baumannii infection was identified as an independent risk factor for biofilm formation on ECMO catheters.

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.

Blood Stream Infection in Patients on Venovenous Extracorporeal Membrane Oxygenation for Respiratory Failure

Bloodstream infection (BSI) occurred in 21 of 121 patients (17%) receiving venovenous extracorporeal membrane oxygenation within the median time of 6 days after initiation (interquartile range, 4-19 days). Longer duration of arterial catheterization and more blood transfusions were independently associated with BSI, which is associated with poor clinical outcomes.Infect Control Hosp Epidemiol 2018;1-4.

Fungal infections in adult patients on extracorporeal life support

BACKGROUND

Patients on extracorporeal membrane oxygenation (ECMO) are often among the most severely ill in the intensive care unit. They are often receiving broad-spectrum antibiotics; they have multiple entry points for pathogens; and their immune system is impaired by blood circuit interaction. These factors are thought to predispose them to fungal infections. We thus aimed to evaluate the prevalence, risk factors, and prognosis of fungal infections in adults on ECMO.

METHODS

We conducted a retrospective cohort study using the Extracorporeal Life Support Organization registry, which compiles data on ECMO use from hundreds of international centers. We included all adult patients from 2006 to 2016 on any mode of ECMO with either a diagnosis of fungal infection or a positive fungal culture.

RESULTS

Our study comprised 2129 adult patients (10.8%) with fungal colonization or infection. Aspergillus involvement (colonization or infection) was present in 272 patients (1.4%), of whom 35.7% survived to hospital discharge. There were 245 patients (1.2%) with Candida invasive bloodstream infection, with 35.9% survival. Risk factors for Aspergillus involvement included solid organ transplant (OR 1.83; p = 0.008), respiratory support (OR 2.75; p < 0.001), and influenza infection (OR 2.48; p < 0.001). Risk factors for candidemia included sepsis (OR 1.60; p = 0.005) and renal replacement therapy (OR 1.55; p = 0.007). In multivariable analysis, Aspergillus involvement (OR 0.40; p < 0.001) and candidemia (OR 0.47; p < 0.001) were both independently associated with decreased survival.

CONCLUSIONS

The prevalence of Aspergillus involvement and Candida invasive bloodstream infection were not higher in patients on ECMO than what has been reported in the general intensive care population. Both were independently associated with a reduced survival. Aspergillus involvement was strongly associated with ECMO for respiratory support and influenza.