Bohman, J. Kyle

Background: Patients with fungal pneumonias sometimes progress to acute respiratory distress syndrome (ARDS). Mortality has been reported as high as 60% to 90% in this group. Venovenous extracorporeal membrane oxygenation (VV-ECMO) can be used to support such patients, however, outcomes are not well understood. Patients and Methods: This was a retrospective study across the four adult ECMO centers in Minnesota for one decade (2012–2022). The outcomes of interest were duration of ECMO, survival rate, and complications. Data were extracted from the electronic medical record and analyzed using descriptive statistics. Results: Fungal pneumonia was the etiology of ARDS in 22 of 422 (5%) adults supported with VV-ECMO during the 10-year study period. Median patient age was 43 years (interquartile range [IQR], 35–56) and 68% were male. By type of fungal infection, 16 (72%) had blastomycosis, five (22%) had pneumocystis, and one (5%) had cryptococcus. Of the 16 patients with blastomycosis two were immunosuppressed whereas all five of the pneumocystis patients were immunosuppressed. The overall survival rate was 73%; most patients with blastomycosis (67%) and pneumocystis (80%) survived to hospital discharge. The duration of ECMO support was greater for the pneumocystis group (median, 30 days; IQR, 21–43) compared with blastomycosis (median, 10 days; IQR, 8–18). Conclusions: Our findings support the use of VV-ECMO for ARDS caused by fungal pneumonias in select immunocompetent and immunocompromised patients. Although survival was high, patients with pneumocystis required longer ECMO runs.

Background: Exposure to hyperoxia, a high arterial partial pressure of oxygen (PaO2), may be associated with worse outcomes in patients receiving extracorporeal membrane oxygenator (ECMO) support. We examined hyperoxia in the Extracorporeal Life Support Organization Registry among patients receiving venoarterial ECMO for cardiogenic shock. Methods: We included Extracorporeal Life Support Organization Registry patients from 2010 to 2020 who received venoarterial ECMO for cardiogenic shock, excluding extracorporeal CPR. Patients were grouped based on PaO2 after 24 hours of ECMO: normoxia (PaO2 60–150 mmHg), mild hyperoxia (PaO2 151–300 mmHg), and severe hyperoxia (PaO2 >300 mmHg). In-hospital mortality was evaluated using multivariable logistic regression. Results: Among 9959 patients, 3005 (30.2%) patients had mild hyperoxia and 1972 (19.8%) had severe hyperoxia. In-hospital mortality increased across groups: normoxia, 47.8%; mild hyperoxia, 55.6% (adjusted odds ratio, 1.37 [95% CI, 1.23–1.53]; P <0.001); severe hyperoxia, 65.4% (adjusted odds ratio, 2.20 [95% CI, 1.92–2.52]; P <0.001). A higher PaO2 was incrementally associated with increased in-hospital mortality (adjusted odds ratio, 1.14 per 50 mmHg higher [95% CI, 1.12–1.16]; P <0.001). Patients with a higher PaO2 had increased in-hospital mortality in each subgroup and when stratified by ventilator settings, airway pressures, acid-base status, and other clinical variables. In the random forest model, PaO2 was the second strongest predictor of in-hospital mortality, after older age. Conclusions: Exposure to hyperoxia during venoarterial ECMO support for cardiogenic shock is strongly associated with increased in-hospital mortality, independent from hemodynamic and ventilatory status. Until clinical trial data are available, we suggest targeting a normal PaO2 and avoiding hyperoxia in CS patients receiving venoarterial ECMO.

Abstract Aims Shock severity predicts mortality in patients with cardiogenic shock (CS). We evaluated the association between pre-cannulation Society for Cardiovascular Angiography and Intervention (SCAI) shock classification and mortality among patients receiving venoarterial (VA) extracorporeal membrane oxygenation (ECMO) support for CS. Methods and results We included Extracorporeal Life Support Organization (ELSO) Registry patients from 2010 to 2020 who received VA ECMO for CS. SCAI shock stage was assigned based on hemodynamic support requirements prior to ECMO initiation. In-hospital mortality was analyzed using multivariable logistic regression. We included 12 106 unique VA ECMO patient runs with a median age of 57.9 (interquartile range: 46.8, 66.1) years and 31.8% were females; 3472 (28.7%) were post-cardiotomy. The distribution of SCAI shock stages at ECMO initiation was: B, 821 (6.8%); C, 7518 (62.1%); D, 2973 (24.6%); and E, 794 (6.6%). During the index hospitalization, 6681 (55.2%) patients died. In-hospital mortality increased incrementally with SCAI shock stage (adjusted OR: 1.24 per SCAI shock stage, 95% CI: 1.17–1.32, P &lt; 0.001): B, 47.5%; C, 52.8%; D, 60.8%; E, 65.1%. A higher SCAI shock stage was associated with increased in-hospital mortality in key subgroups, although the SCAI shock classification was only predictive of mortality in non-surgical (medical) CS and not in post-cardiotomy CS. Conclusion The severity of shock prior to cannulation is a strong predictor of in-hospital mortality in patients receiving VA ECMO for CS. Using the pre-cannulation SCAI shock classification as a risk stratification tool can help clinicians refine prognostication for ECMO recipients and guide future investigations to improve outcomes.

OBJECTIVES: To provide a comparative analysis of conventional heparin-versus bivalirudin-based systemic anticoagulation in adult and pediatric patients supported on extracorporeal membrane oxygenation. DESIGN: Retrospective chart review study of adult and pediatric patients receiving extracorporeal membrane oxygenation from January 1, 2014, to October 1, 2019. SETTING: A large, high-volume tertiary referral adult and pediatric extracorporeal membrane oxygenation center. PATIENTS: Four hundred twenty-four individuals requiring extracorporeal membrane oxygenation support and systemically anticoagulated with either unfractionated heparin (223 adult and 65 pediatric patients) or bivalirudin (110 adult and 24 pediatric patients) were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Digital data abstraction was used to retrospectively collect patient details. The majority of both groups were cannulated centrally (67%), and the extracorporeal membrane oxygenation type was predominantly venoarterial (84%). The adult bivalirudin group had a greater occurrence of heparin-induced thrombocytopenia (12% vs 1%; p < 0.01) and was more likely to require postcardiotomy extracorporeal membrane oxygenation (36% vs 55%; p < 0.01). There were no statistical differences between the groups in regards to age, sex, and extracorporeal membrane oxygenation initiation location. The main finding was a reduced mortality in the adult bivalirudin group (odds ratio, 0.39; p < 0.01), whereas no difference was noted in the pediatric group. A significant reduction in the composite transfusion requirement in the first 24 hours was noted in the pediatric bivaluridin group with an odds ratio of 0.28 (p = 0.02). Groups did not differ in regard to laboratories per day, anticoagulant dose adjustments, or ischemic complications. CONCLUSIONS: When compared with heparin-based systemic anticoagulation, bivalirudin demonstrated feasibility and safety as established by the absence of increases in identifiable adverse outcomes while manifesting substantial improvements in hospital mortality in adult patients. Further studies are necessary to corroborate these findings and further elucidate the role of bivalirudin during extracorporeal membrane oxygenation support.

BACKGROUND: Current mechanical ventilation practice and the use of treatment adjuncts in patients requiring extracorporeal membrane oxygenation (ECMO) for refractory hypoxemia (RH) vary widely and their impact on outcomes remains unclear. In 2015, we implemented a standardized approach to protocolized ventilator settings and guide the escalation of adjunct therapies in patients with RH. This study aimed to investigate ICU mortality, its associated risk factors, and mechanical ventilation practice before and after the implementation of a standardized RH guideline in patients requiring venovenous ECMO (VV-ECMO). METHODS: This was a single-center, retrospective cohort study of patients undergoing VV-ECMO due to RH respiratory failure between January 2008 and March 2015 (before RH protocol implementation) and between April 2015 and October 2019 (after RH protocol implementation). RESULTS: A total of 103 subjects receiving VV-ECMO for RH were analyzed. After implementation of the RH protocol, more subjects received prone positioning (6.7% vs 23.3%, P = .02), and fewer received high-frequency oscillatory ventilation than before launching the RH protocol (0% vs 13.3%, P = .01). Plateau pressure was also lower before initiation of ECMO ( P = .04) and at day 1 during ECMO ( P = .045). Driving pressure was consistently lower at days 1, 2, and 3 after ECMO initiation: median 13.0 (interquartile range [IQR] 10.6–18.0) vs 16.0 (IQR 14.0–20.0) cm H 2 O at day 1 ( P = .003); 13.0 (IQR 11.0–15.9) vs 15.5 (IQR 12.0–20.0) cm H 2 O at day 2 ( P = .03); and 12.0 (IQR 10.0–14.5) vs 15.0 (IQR 12.0–19.0) cm H 2 O at day 3 ( P = .005). CONCLUSIONS: The implementation of a standardized RH guideline improved compliance with a lung-protective ventilation strategy and utilization of the prone position and was associated with lower driving pressure during the first 3 days after ECMO initiation in subjects with refractory hypoxemia.

Abstract 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.

Severe acute respiratory distress syndrome (ARDS) unresponsive to conventional intensive care unit (ICU) management is an accepted indication for venovenous extracorporeal membrane oxygenation (V-V ECMO) support. The frequency with which patients with coronavirus disease 2019 (COVID-19) pneumonia are selected for V-V ECMO has not been described. This was a cohort study including all patients placed on either V-V ECMO or venoarteriovenous ECMO at the four adult ECMO Centers of Excellence. Primary outcomes evaluated were survival to decannulation from the ECMO circuit, survival to discharge, and 60-day survival. Secondary outcomes were hospital length of stay (LOS), ICU LOS, length of ECMO cannulation, and length of intubation. During the study period, which corresponded to the first surge in COVID-19 hospitalizations in Minnesota, 35 patients with ARDS were selected for V-V ECMO support out of 1,849 adult ICU patients with COVID-19 infection in the state (1.9% incidence; 95% CI, 1.3–2.6%). This represents 46 (95% CI, 34–61) expected V-V ECMO patients per 100,000 confirmed positive cases of COVID-19. Twenty-six of the 35 patients (74.3%) supported with V-V ECMO survived to 60-day post-ECMO decannulation. Recent studies have demonstrated ongoing success rescuing patients with severe ARDS in COVID-19 infection. Our data add to the support of ECMO and the consideration for encouraging cooperation among regional ECMO centers to ensure access to this highest level of care. Finally, by evaluating all the patients of a single region, we estimate overall need for this resource intensive intervention based on the overall number of COVID-19 cases and ICU admissions.