Epidemiology of blood stream infection in adult extracorporeal membrane oxygenation patients: A cohort study

A systematic review of variability in the reporting of extracorporeal membrane oxygenation-associated infections and recommendations for standardization

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) utilization has surged in recent years, particularly amidst the COVID-19 pandemic, yet standardization of ECMO-associated infection (EAI) reporting remains lacking.

METHODS

This systematic review assessed 60 studies from 2018 to 2023 in PubMed, which used key words related to EAIs. Adherence to reporting data elements that may bias reporting, including the use of standardized rates of infections per 1,000 patient days, describing the use of antimicrobial prophylaxis, infection control, and culture practices, describing the definitions for infection by site, and listing pathogens by infection site were evaluated by study.

RESULTS

Our review revealed considerable heterogeneity in data elements and infection definitions. While 51 (85%) studies reported definition by site, only 17 (28%) reported infection control practices, and only 6 (10%) studies adhered to all the identified essential reporting elements. Variation in infection rates was also evident across the definitions, with studies using their own definition having the greatest variability in reported infection rates. Microbiological differences by geographic region further underscored the need for standardized reporting and challenges with generalizability in the EAI literature.

CONCLUSIONS

Our findings underscore the imperative for consensus on ECMO infection definitions and transparent reporting practices to facilitate meaningful comparisons and advance patient care protocols.

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.

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.

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.

Prophylactic antibiotic treatment for preventing nosocomial infection in extracorporeal membrane oxygenation-resuscitated circulatory arrest patients

Objective

We aimed to investigate the characteristics of nosocomial infections (NIs) and the impact of prophylactic antibiotic administration on NI outcomes in patients who underwent extracorporeal cardiopulmonary resuscitation (ECPR).

Methods

This retrospective study analyzed the rate, type, pathogens, outcomes, and risk factors of NIs that developed in adult patients who underwent ECPR at our institution between January 2002 and January 2022.

Results

Among 105 patients (median age, 58.59 [interquartile range, 46.53-67.32] years), 57 (54.29%) patients developed NIs during their extracorporeal membrane oxygenation courses. The incidence rates per 1000 extracorporeal membrane oxygenation days were 135.91 for overall infections and 40.06 for multidrug-resistant (MDR) infections. Ventilator-associated pneumonia was the most common type of NI (73.68%), followed by bloodstream infections (17.89%). Prophylactic antibiotics with Pseudomonas aeruginosa coverage were protective factors against NI (hazard ratio [HR], 0.518; 95% confidence interval [CI], 0.281-0.953; P = .034). High dynamic driving pressure of the ventilator (cmH2O) was a prognostic factor for hospital mortality (HR, 1.096; 95% CI, 1.008-1.192; P = .032). An Acute Physiology and Chronic Health Evaluation II score of ≥24 (HR, 6.443; 95% CI, 1.380-30.088; P = .018) was a risk factor for developing MDR infections.

Conclusions

In patients who undergo ECPR, prophylactic antibiotic treatment with P aeruginosa coverage is associated with a lower incidence of NIs, whereas an Aeruginosa Acute Physiology and Chronic Health Evaluation II score of ≥24 is a risk factor for MDR infections. In the modern era of antibiotic therapy, the development of NIs does not increase hospital mortality among patients undergoing ECPR.

Bloodstream infection and ventilator-associated pneumonia in patients with coronavirus disease 2019 (COVID-19) supported by extracorporeal membrane oxygenation

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) has been widely used in the care of patients with respiratory failure from coronavirus disease 2019 (COVID-19). We characterized bloodstream infections (BSIs) and ventilator-associated pneumonias (VAPs) in COVID-19 patients supported with ECMO, and we investigated their impact on patient outcomes.

DESIGN

Retrospective cohort study from March 1, 2020, to June 30, 2021.

SETTING

Academic tertiary-care referral center.

PATIENTS

Consecutive adult patients admitted for COVID-19 who received ECMO.

METHODS

We identified BSIs and VAPs and described their epidemiology and microbiology. Cumulative antimicrobial use and the specific management of BSIs were determined. Multivariate time-dependent Cox proportional hazards models were constructed to evaluate the impact of BSIs and VAPs on mortality, controlling for age, receipt of COVID-19-specific therapeutics, and new renal replacement therapy.

RESULTS

We identified 136 patients who received ECMO for COVID-19 pneumonia during the study period. BSIs and VAPs occurred in 81 patients (59.6%) and 93 patients (68.4%), respectively. The incidence of BSIs was 29.5 per 1,000 ECMO days and increased with duration of ECMO cannulation. Enterococci, Enterobacterales, and Staphylococcus aureus were the most common causes of BSIs, whereas S. aureus, Klebsiella species, and Pseudomonas aeruginosa comprised the majority of VAPs. Mean antibiotic use comprised 1,031 days of therapy per 1,000 ECMO days (SD, 496). We did not detect an association between BSIs or VAPs and mortality.

CONCLUSIONS

BSIs and VAPs are common in COVID-19 ECMO-supported patients. Efforts to optimize their diagnosis, prevention, and management should be prioritized.

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.

Analysis of the use of empiric antimicrobial prophylaxis for temporary cardiac devices at a large academic medical center

INTRODUCTION

Varying rates of access site infections with temporary percutaneous cardiac devices have been reported in the literature. The purpose of this study is to determine the impact of a change in institutional practice in utilizing antimicrobial prophylaxis to prevent access site infections in patients with these devices.

METHODS

This observational, pre-post implementation analysis evaluated the benefit of prophylactic antimicrobial therapy in adult patients with temporary percutaneous cardiac devices admitted to cardiac intensive care units. Patients in the pre-cohort received prophylactic antibiotics for the duration of device insertion. Patients in the post-cohort received a single dose of intravenous antibiotics for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) or Impella® 5.5 device placement, and no antimicrobial prophylaxis for all other devices placed. The primary endpoint was the incidence of definitive access site infection. Secondary endpoints included the incidence of Clostridium difficile infection and initiation of broad-spectrum antibiotics.

RESULTS

Fifty patients in the pre-cohort and 45 patients in the post-cohort were evaluated. Devices included intra-aortic balloon pumps, VA-ECMO, Impella® CP and Impella® 5.5. The median duration of device insertion was four days. No significant difference in the primary outcome was seen between the two groups. A significant reduction in prophylactic antimicrobial utilization and total days of antimicrobial exposure was observed in the post-implementation cohort.

CONCLUSION

Based on the results of our study, the implemented guideline reduces the utilization of antimicrobial prophylaxis in patients with temporary percutaneous cardiac devices and does not result in an increased rate of infections.

Complications Associated With Venovenous Extracorporeal Membrane Oxygenation-What Can Go Wrong?

OBJECTIVES

Despite increasing use and promising outcomes, venovenous extracorporeal membrane oxygenation (V-V ECMO) introduces the risk of a number of complications across the spectrum of ECMO care. This narrative review describes the variety of short- and long-term complications that can occur during treatment with ECMO and how patient selection and management decisions may influence the risk of these complications.

DATA SOURCES

English language articles were identified in PubMed using phrases related to V-V ECMO, acute respiratory distress syndrome, severe respiratory failure, and complications.

STUDY SELECTION

Original research, review articles, commentaries, and published guidelines from the Extracorporeal Life support Organization were considered.

DATA EXTRACTION

Data from relevant literature were identified, reviewed, and integrated into a concise narrative review.

DATA SYNTHESIS

Selecting patients for V-V ECMO exposes the patient to a number of complications. Adequate knowledge of these risks is needed to weigh them against the anticipated benefit of treatment. Timing of ECMO initiation and transfer to centers capable of providing ECMO affect patient outcomes. Choosing a configuration that insufficiently addresses the patient's physiologic deficit leads to consequences of inadequate physiologic support. Suboptimal mechanical ventilator management during ECMO may lead to worsening lung injury, delayed lung recovery, or ventilator-associated pneumonia. Premature decannulation from ECMO as lungs recover can lead to clinical worsening, and delayed decannulation can prolong exposure to complications unnecessarily. Short-term complications include bleeding, thrombosis, and hemolysis, renal and neurologic injury, concomitant infections, and technical and mechanical problems. Long-term complications reflect the physical, functional, and neurologic sequelae of critical illness. ECMO can introduce ethical and emotional challenges, particularly when bridging strategies fail.

CONCLUSIONS

V-V ECMO is associated with a number of complications. ECMO selection, timing of initiation, and management decisions impact the presence and severity of these potential harms.

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.

Platelet Transfusion and In-Hospital Mortality in Veno-Arterial Extracorporeal Membrane Oxygenation Patients

Thrombocytopenia is common during extracorporeal membrane oxygenation (ECMO), and platelets are sometimes transfused to meet arbitrary goals. We performed a retrospective cohort study of veno-arterial (VA) ECMO patients from a single academic medical center and explored the relationship between platelet transfusion and in-hospital mortality using multivariable logistic regression. One hundred eighty-eight VA ECMO patients were included in the study. Ninety-one patients (48.4%) were transfused platelets during ECMO. Patients who received platelet transfusion had more coronary artery disease, lower platelet counts at cannulation, higher predicted mortality, lower nadir platelet counts, more ECMO days, and more red blood cell (RBC) and plasma transfusion. Mortality was 19.6% for patients who received no platelets, 40.8% for patients who received 1-3 platelets, and 78.6% for patients who received 4 or more platelets ( P &lt; 0.001). After controlling for confounding variables including baseline severity of illness, central cannulation, postcardiotomy status, RBC and plasma transfusion, major bleeding, and total ECMO days, transfusion of 4 or more platelets remained associated with in-hospital mortality; OR = 4.68 (95% CI = 1.18-27.28), P = 0.03. Our findings highlight the need for randomized controlled trials that compare different platelet transfusion triggers, so that providers can better understand when platelet transfusion is indicated in VA ECMO patients.

Risk factors for bloodstream infection (BSI) in patients with severe acute respiratory distress syndrome (ARDS) supported by veno-venous extracorporeal membrane oxygenation (VV-ECMO)

Background

There were relatively few studies about the incidence and risk factors for bloodstream infection (BSI) in patients with severe acute respiratory distress syndrome (ARDS) supported by veno–venous extracorporeal membrane oxygenation (VV–ECMO).

Methods

Patients who were diagnosed with severe ARDS and received VV–ECMO treatment in the medical intensive care unit of China–Japan Friendship Hospital from August 2013 to March 2019 were retrospectively studied. The pathogens isolated from blood culture (BC) were identified and analyzed for drug sensitivity. The risk factors for BSI were analyzed by logistic regression.

Results

A total of 105 patients were included in this single–center retrospective cohort study. Among them, 23 patients (22%) had BSIs. 19 cases were identified as primary BSI; while the other 4 cases were as secondary BSI. A total of 23 pathogenic strains were isolated from BCs, including gram–negative (G^–) bacilli in 21 (91%) cases, gram–positive (G⁺) cocci in 1 case, fungus in 1 case, and multidrug–resistant (MDR) organisms in 8 cases. Compared with patients without BSI, patients with BSI had a higher Murray score (odds ratio = 6.29, P = 0.01) and more blood transfusion (odds ratio = 1.27, P = 0.03) during ECMO.

Conclusions

The incidence of BSI in patients with severe ARDS supported by VV–ECMO was 22%. G^– bacilli was the main pathogen, and most of them were MDR–G^– bacilli (MDR–GNB). Higher Murray score and more blood transfusion may be the independent risk factors for BSI.

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.

Extremity fasciotomy for patients on extracorporeal membrane oxygenation is independently associated with inpatient mortality

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) maintains end-organ perfusion in critically ill patients with cardiac or respiratory failure; however, ECMO cannulation in the extremities has been associated with significant limb ischemia and risk of compartment syndrome. Current literature on ECMO and fasciotomies is limited to small single-center retrospective studies. This study aimed to (1) compare the incidence of postoperative outcomes and mortality in patients undergoing fasciotomy while on ECMO to those of non-fasciotomy ECMO patients, and (2) assess the difference in adjusted mortality risk between the two groups.

HYPOTHESIS

We hypothesized that patients undergoing fasciotomy while on ECMO would have significantly higher odds of in-hospital mortality than non-fasciotomy ECMO patients after adjustment for perioperative variables.

METHODS

We conducted a retrospective review of NIS from January 1st, 2012-September 30, 2015 for all hospitalizations involving ECMO and stratified them into two cohorts based on whether they underwent fasciotomy after ECMO. Patient baseline characteristics, in-hospital procedures, and postoperative outcomes were compared between the two cohorts. Logistic regression was used to assess in-hospital mortality risk between the two cohorts adjusting for age, sex, Elixhauser score, and perioperative procedures and non-fasciotomy perioperative morbidity.

RESULTS

There were 7,085 estimated eligible discharges between 2012 and 2015 identified, 149 (2.1%) of which underwent fasciotomy following ECMO. One hundred and thirteen of the 149 hospitalizations (77%) in the fasciotomy cohort resulted in in-hospital mortality, compared to 3,805 of the 6,936 (55%) in the non-fasciotomy cohort. There were no differences in rates of transfusion (p=0.290), length of stay (p=0.282), or discharge disposition (p=0.126) between the two cohorts. In the logistic regression model, the fasciotomy cohort had a higher odds of in-hospital mortality than non-fasciotomy cohort (OR, 2.5; 95% CI, 1.1-5.6).

DISCUSSION

Operative treatment of acute compartment syndrome for patients on ECMO therapy is associated with significantly increased mortality and morbidity. Whether fasciotomy is a marker of sickness or represents a cause-and-effect relationship is unknown and future should investigate the role of non-operative treatment of compartment syndrome on mortality in this population.

LEVEL OF EVIDENCE

III; Prognostic.

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.

Characteristics of venous-venous extracorporeal membrane oxygenation related bloodstream infections

BACKGROUND

Infectious complications have been shown to increase the morbidity of venous-venous extracorporeal membrane oxygenation (VV-ECMO) population, including the use of right ventricular assist devices.

AIM

We aimed to evaluate our VV-ECMO population for ECMO related bloodstream infections (E-BSI) and characteristics that affect risk and overall outcomes.

METHODS

A retrospective chart review of adult patients (>18 years of age)supported with VV ECMO was conducted. Demographic data as well as antimicrobial use and presecence of bacteremia was collected.

RESULTS

We report a low infection rate of 2.7%.

CONCLUSIONS

We postulate our low BSI rate may be due to our use of perioperative antimicrobials as well as a majority of our cannulations occurring in the operating room. We do not routinely utilize prophylactic antimicrobials on ECMO. Further investigation into trends, risks, and outcomes related to E-BSI is needed.

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.

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.

Reducing Broad-Spectrum Antimicrobial Use in Extracorporeal Membrane Oxygenation: Reduce AMMO Study

Background

The use of extracorporeal membrane oxygenation (ECMO) in critically ill adults is increasing. There are currently no guidelines for antimicrobial prophylaxis. We analyzed 7 years of prophylactic antimicrobial use across 3 time series for patients on ECMO at our institution in the development, improvement, and streamlining of our ECMO antimicrobial prophylaxis protocol.

Methods

In this quasi-experimental interrupted time series analysis, we evaluated the impact of an initial ECMO antimicrobial prophylaxis protocol, implemented in 2014, on antimicrobial use and National Healthcare Safety Network–reportable infection rates. Then, following a revision and streamlining of the protocol in November 2018, we reevaluated the same metrics.

Results

Our study population included 338 intensive care unit patients who received ECMO between July 2011 and November 2019. After implementation of the first version of the protocol, we did not observe significant changes in antimicrobial use or infection rates in these patients; however, following revision and streamlining of the protocol, we demonstrated a significant reduction in broad-spectrum antimicrobial use for prophylaxis in patients on ECMO without any evidence of a compensatory increase in infection rates.

Conclusions

Our final protocol significantly reduces broad-spectrum antimicrobial use for prophylaxis in patients on ECMO. We propose a standard antimicrobial prophylaxis regimen for patients on ECMO based on current evidence and our experience.

Summary: There are no guidelines for antimicrobial prophylaxis in patients on extracorporeal membrane oxygenation (ECMO). A rational approach employing concepts of antimicrobial stewardship can drive logical antimicrobial selection for prophylaxis in patients on ECMO without adversely impacting outcomes.

Acute Brain Injury in Postcardiotomy Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVE

Acute brain injury (ABI) is common in venoarterial extracorporeal membrane oxygenation (VA-ECMO). One of the most common indications for use of VA-ECMO is postcardiotomy shock (PCS). The authors aimed to characterize the prevalence of ABI and its association with outcomes in this population.

DESIGN

prospective observational.

SETTING

Single-center tertiary care university hospital.

PARTICIPANTS

Fifty-two consecutive patients treated for PCS with VA-ECMO from November 2017 to March 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The median age of patients was 64 (interquartile range 44-84), 62% were male. Of 52 PCS patients treated with extracorporeal membrane oxygenation, 38% (n = 20) experienced acute brain injury. Ischemic stroke was the most common (n = 13, 25%). Patients with central versus peripheral cannulation experienced more ischemic and hemorrhagic strokes (8% v 38%, p = 0.04). Patients with intracardiac thrombus experienced more brain injury (n = 4, 8% p = 0.02). The in-hospital mortality in patients with brain injury was 90% (n = 18/20) compared to 78% (n = 25/32) in patients without brain injury.

CONCLUSIONS

ABI is common in postcardiotomy VA-ECMO and associated with worse outcome. Patients with central recanalization experienced the majority of acute strokes. Intracardiac thrombus was significantly associated with acute brain injury.

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.

The Year in Cardiothoracic Critical Care: Selected Highlights from 2019

In 2019, cardiothoracic and vascular critical care remained an important focus and subspecialty. This article continues the annual series to review relevant contributions in postoperative critical care that may affect the cardiac anesthesiologist. Herein, the pertinent literature published in 2019 is explored and organized by organ system.

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.

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.

Controversies in Perioperative Antimicrobial Prophylaxis

Although clinical guidelines for antibiotic prophylaxis across a wide array of surgical procedures have been proposed by multidisciplinary groups of physicians and pharmacists, clinicians often deviate from recommendations. This is particularly true when recommendations are based on weak data or expert opinion. The goal of this review is to highlight certain common but controversial topics in perioperative prophylaxis and to focus on the data that does exist for the recommendations being made.