Bohman, J. Kyle

In this retrospective cohort study at a quaternary referral hospital, 829 adult patients supported by extracorporeal membrane oxygenation (ECMO) between January 1, 2014, and October 31, 2024, were screened for ventilator-associated pneumonia (VAP). The incidence of VAP in ECMO-supported patients was 17.7 per 1,000 ECMO days (venoarterial [VA] ECMO, 22.1 per 1,000 ECMO days; venovenous [VV] ECMO, 13.8 per 1,000 ECMO days). Median time from ECMO cannulation to diagnosis of VAP was 4 (interquartile range [IQR], 3–8; range 1–84) days. Gram-negative bacteria comprised most respiratory pathogens. A significant increase in minimum ECMO sweep was noted from 2 days before to 1 day after VAP diagnosis (0.79 L/min increase, p = 0.004). Only 38 of 153 patients (24.8%) met National Healthcare Safety Network (NHSN) VAP definitions. After creating a modified VAP definition, which included an ECMO sweep increase of 0.5 L/min as evidence of worsening respiratory status, 78 (51.0%) met the modified definition. Those who met the modified VAP definition had worse in-hospital (60.3% vs. 28.0%, p < 0.001), 30 day (33.3% vs. 17.3%, p = 0.023), and 90 day (53.8% vs. 25.3%, p < 0.001) mortality compared with those who did not meet the modified VAP definition. The incorporation of ECMO parameters into diagnostic criteria may improve detection sensitivity, but further validation is necessary before implementation.

Emerging evidence links veno-venous extracorporeal membrane oxygenation (VV-ECMO) to right ventricular (RV) dysfunction, but the relative contribution of ECMO versus underlying disease progression remains unclear. We conducted a multicenter, retrospective, propensity-matched study including 408 intubated acute respiratory distress syndrome (ARDS) patients who were admitted between January 2020 and October 2024 in a quaternary referral hospital network within the United States and underwent at least two transthoracic echocardiograms (TTEs) after intubation. Using 1:2 propensity score matching, we adjusted for baseline comorbidities, baseline hemoglobin, lactate, and worst PaO 2 /FiO 2 ratio (P/F). Longitudinal echocardiographic changes were analyzed with a cumulative link mixed model (CLMM), evaluating RV size and function as ordinal outcomes. Within 408 patients (112 received ECMO support), propensity matching identified 55 ECMO and 110 non-ECMO patients with balanced baseline characteristics. Among 469 serial echocardiograms, RV size and function worsened more frequently in ECMO patients. In longitudinal modeling, ECMO use alone was not associated with RV dilation ( p = 0.23) or dysfunction ( p = 0.43). However, longer ECMO duration was associated with RV dilation (OR: 1.04 per day, p = 0.004) and dysfunction (odds ratio [OR]: 1.04 per day, p < 0.001). Higher ECMO circuit flow had a trend toward progressive RV dilation and dysfunction but did not reach statistical significance. These findings highlight the need for vigilant RV monitoring during ECMO support.

Background The prognostic significance of an adverse acid–base milieu despite venoarterial extracorporeal membrane oxygenation support in patients with cardiogenic shock remains poorly defined. We examined metabolic and respiratory disturbances in the ELSO (Extracorporeal Life Support Organization) Registry among patients who received venoarterial extracorporeal membrane oxygenation support for refractory cardiogenic shock. Methods Arterial blood gas acid–base values at 24 hours following venoarterial extracorporeal membrane oxygenation initiation were analyzed, with patients classified by pH, arterial partial pressure of carbon dioxide, and bicarbonate. Multivariable logistic regression and exploratory machine learning analyses were used to assess predictors of in‐hospital mortality. Results Among 15 144 adult patients, 74.6% (10 860) had neither respiratory nor metabolic acidosis, 13.1% (1909) had isolated respiratory acidosis, 11.6% (1684) had isolated metabolic acidosis, and 0.7% (100) had combined acidosis. In‐hospital mortality occurred in 7719 (51.0%) patients and increased incrementally across patients with lower pH (adjusted odds ratio [OR], 2.03 with each 0.1‐unit decrease in pH, using 7.4 as a reference point [95% CI, 1.82–2.26]), bicarbonate (adjusted OR, 1.93 per each 5‐mEq/L <24 mEq/L [95% CI, 1.76–2.12]) or base excess (adjusted OR, 1.90 per each 5‐mEq/L <0 mEq/L [95% CI, 1.75–2.07]) (all P <0.01). Mortality varied significantly, being highest for the low‐pH metabolic acidosis cluster (adjusted OR, 1.90 [95% CI, 1.70–2.12], P <0.01). Conclusions Survival decreased progressively with worse acidemia or metabolic acidosis despite 24 hours of hemodynamic support with venoarterial extracorporeal membrane oxygenation among patients with cardiogenic shock. Our findings emphasize the prognostic significance of metabolic parameters as potentially modifiable risk factors and underscore the need for early recognition and interventions to mitigate severe metabolic derangements.

Introduction: Cardiopulmonary bypass time (CPBT) and aortic cross-clamp time (AXCT) are independently associated with postoperative morbidity and mortality. However, no universally accepted “optimal” duration exists, as these times are influenced by the complexity of cardiac surgery. ECMO is being increasingly used for cardiogenic shock in patients undergoing cardiotomy, but the impact of CPBT and AXCT on outcomes in this specific population remains unexplored. This study investigates how CPBT and AXCT influence outcomes in cardiotomy patients on ECMO support. Research Question: Do CPBT and AXCT influence mortality and complication rates in cardiotomy patients receiving ECMO support? Methods: We conducted a retrospective chart review (Jan 2020–Dec 2024) across a multidisciplinary North American practice, identifying 623 patients who required ECMO. Of these, 236 (37.8%) received ECMO in the preoperative, intraoperative, or postoperative period of cardiotomy. Patients were grouped by prolonged CPBT (>150 min) vs standard (≤150 min) and prolonged AXCT (>90 min) vs standard (≤90 min). We analyzed outcomes including 30-day mortality, ECMO characteristics, and postoperative complications. Results: Among the 236 patients, the average age was 60.8 years, BMI 37.43 kg/m 2 ; 63% were male, 85% White. Prolonged CPBT and AXCT were associated with higher BMI (p=0.02, 0.03), prior cardiac surgery (p<0.001, 0.006), and combined CABG+AVR procedures (p=0.01, 0.001). Patients with prolonged durations were more likely to require postoperative ECMO (p=0.001, 0.03). Complications such as mediastinal bleeding, AKI requiring CRRT, mediastinitis, bacteremia, and pneumonia, showed significant association with increased CPBT whereas prolonged AXCT was only linked with mediastinal bleeding. CPBT and AXCT durations did not significantly affect 30-day mortality, ICU/hospital stay, ECMO duration, or ventilation duration. Independent predictors of 30-day mortality included pre-/intraoperative IABP use (OR 2.19, 95% CI 1.11–4.30, p=0.023), Impella use (OR 0.20, 95% CI 0.03–0.75, p=0.040), post-op intracranial bleeding (OR 5.46, 95% CI 1.43–23.9, p=0.016), and CRRT-requiring AKI (OR 3.24, 95% CI 1.63–6.57, p<0.001). Conclusion: Prolonged CPBT and AXCT were significantly linked to higher rates of postoperative complications such as mediastinal bleeding, CRRT requiring AKI, mediastinitis, and pneumonia along with increased need for postoperative ECMO support, without significantly affecting mortality.

Objectives To determine whether a nurse practitioner and physician assistant (NP/PA)-led rapid staffing. Model in the cardiac surgical intensive care unit (ICU) can optimize resource utilization without compromising safety or increasing hospital length of stay (LoS). Design Retrospective observational cohort study comparing before-and-after implementation of an NP/PA-led rapid recovery pathway. Setting A large tertiary referral academic cardiac surgery ICU. Participants There were 116 patients in the prerapid recovery cohort and 153 in the postimplementation rapid recovery phase. Interventions Low-risk cardiac surgery patients were selected for postoperative care by an NP/PA-led ICU staffing model. Measurements and Main Results Mean hospital LoS in the prerapid recovery cohort was 5.7 days compared to 5.2 days in the rapid recovery pathway cohort ( P = .02). Thirty-day hospital readmission in the prerapid recovery pathway cohort was 7.8% compared with 2.0% in the rapid recovery cohort ( P = .04). The ICU readmission rate for prerapid recovery cohort was 4.3%, while the rapid recovery percentage was 2.0% ( P = .30). Conclusions Overall, implementation of an NP/PA-led postcardiac surgical ICU team ( rapid recovery pathway) was associated with similar ICU LoS, hospital LoS, ICU readmission rates, 30-day readmission rates, and no significant signal of increased adverse events or safety concerns.

Background: While criteria for the diagnosis of nosocomial pneumonias exist, objective definitions are a challenge and there is no gold standard for diagnosis. We analyzed the impact of the implementation of a logical, consensus-based diagnostic and treatment protocol for managing nosocomial pneumonias in the cardiovascular surgery intensive care unit (CVS-ICU). Methods: We conducted a quasi-experimental, interrupted time series analysis to evaluate the impact of a diagnostic and treatment protocol for nosocomial pneumonias in the CVS-ICU. Impacts were measured relative to patient outcomes, diagnostic processes, and antimicrobial stewardship improvement. Descriptive statistics were used to analyze results. Results: Overall, 35 pre-protocol and 39 post-protocol patients were included. Primary clinical variables suggesting pneumonia in pre- and post-protocol patients were new lung consolidation (50% vs. 71%), new leukocytosis (59% vs. 64%), and positive culture (32% vs. 55%). Appropriate diagnostic testing improved (23% vs. 54%, p = 0.008) after protocol implementation. The proportion of patients meeting the criteria for nosocomial pneumonia (77% vs. 87%) was not statistically significant, though more patients in the post-protocol group met probable diagnostic criteria (51% vs. 77%). Duration of therapy was not significantly different (6 days [IQR = 5.0, 10.0] vs. 7 days [IQR = 6.0, 9.0]). Conclusions: The implementation of a diagnostic and treatment protocol for management of nosocomial pneumonias in the CVS-ICU resulted in improved diagnostic accuracy, advanced antimicrobial and diagnostic stewardship efforts, and laboratory cost savings without an adverse impact on patient-centered outcomes.

Extracorporeal membrane oxygenation (ECMO) is often used in acute respiratory distress syndrome (ARDS) with refractory hypoxemia. There is limited literature highlighting the development of right ventricular (RV) failure while on ECMO. We conducted a retrospective multicenter observational study including 70 patients who were placed on veno-venous (VV)-ECMO for respiratory failure at Mayo Clinic, Jacksonville, and Mayo Clinic, Rochester, between January 2018 and June 2022 and had at least two post-ECMO transthoracic echoes. The primary outcomes were the incidence and progression of RV dysfunction and dilatation. The secondary outcome was in-patient mortality. Among 70 patients in our cohort, 60.6% had a normal RV function at the time of ECMO placement, whereas only 42% had a normal RV function at the second post-ECMO echo. On multinomial regression, a moderate decrease in RV function was associated with ECMO flow (odds ratio [OR] = 2.32, p = 0.001) and ECMO duration (OR = 1.01, p = 0.01). A moderately dilated RV size was also associated with ECMO flow (OR = 2.62, p < 0.001) and ECMO duration (OR = 1.02, p = 0.02). An increasing degree of RV dysfunction was associated with worse outcomes. Our study showed that the increasing duration and flow of VV-ECMO correlated with progressive RV dilatation and dysfunction, which were associated with poor survival.

As the availability of extracorporeal membrane oxygenation (ECMO) expands, so has the need for interfacility transfer to ECMO centers. However, the impact of these transfers is unknown. We hypothesized that interfacility transfers would be associated with increased complications and mortality. This retrospective cohort study includes adult patients treated with venovenous (VV) ECMO at all four adult ECMO centers comprising our statewide registry. Complications, mortality, ECMO duration, length of stay, and disposition were compared based on cannulation at an ECMO center versus outside hospital and transferred by air versus ground after adjusting for baseline covariates/parameters. The study included 420 adult patients, 36% of whom were cannulated at an outside institution before transfer. Of these, 63% were transported by ground and the remainder by air. Risk adjusted logistic regression revealed similar odds of mortality between those cannulated at ECMO centers versus referring hospital and then transported (odds ratio [OR] = 0.77, confidence interval [CI] = 0.49–1.22). This study supports the practice of interfacility ECMO transfer.