Triage of V-V ECMO referrals for COVID-19 respiratory failure.

BACKGROUND: As the pandemic progressed, the use of extracorporeal membrane oxygenation (ECMO) for COVID-19-related acute respiratory distress syndrome increased, and patient triage and transfer to ECMO centers became important to optimize patient outcomes. Our objectives are to identify predictors of patient transfer for veno-venous extracorporeal membrane oxygenation (V-V ECMO) evaluation as well as to describe the outcomes of accepted patients. METHODS: This is a single-center, retrospective analysis of V-V ECMO transfer requests for adult patients with known or suspected COVID-19 and respiratory failure from March 2020 until March 2021. Data were collected prospectively during the triage process for transfer requests as part of clinical patient care at our institution. RESULTS: Of 341 referred patients, 112 (33%) were accepted for transfer to our facility, whereas 229 (67%) patients were declined for transfer. The Classification and Regression Tree analysis showed that patients' high pressure during airway pressure release ventilation (APRV) and age were the variables most significantly associated with the decision to accept or decline patients for transfer. CONCLUSIONS: Our triage process enabled one-third of referred patients to be transferred for evaluation, with nearly 70% of those patients ultimately receiving ECMO support. High ventilator settings on APRV and young age were associated with acceptance for transfer. Accepted patients also had a higher incidence of adjunctive therapies (proning and paralysis) prior to transfer request, less cardiac or renal dysfunction, and a shorter duration of mechanical ventilation. Further research is warranted to investigate the outcomes of nontransferred patients.

Nutrition and outcomes in venovenous extracorporeal membrane oxygenation: An observational cohort study.

BACKGROUND: Overfeeding and underfeeding are associated with negative outcomes during critical illness. The purpose of this retrospective study was to assess the association between nutrition intake and outcomes for patients receiving venovenous (VV) extracorporeal membrane oxygenation (ECMO). METHODS: Adults who received VV ECMO August 2017 to June 2020 were screened. Patients with <3 ECMO nutrition support days were excluded. Age, sex, height, weight, ideal body weight (IBW), body mass index, sequential organ failure assessment score, respiratory ECMO survival prediction score, energy, and protein goals were collected. All nutrition intake was collected for the first 14 days of ECMO or until death, decannulation, or oral diet initiation. Outcomes analyzed included mortality and VV ECMO duration. The relationship between nutrition delivery and outcomes was tested with multivariate analysis. Univariate analyses were conducted on obese and nonobese subgroups. RESULTS: A total of 2044 nutrition days in 178 patients were analyzed. The median estimated needs were 24 (interquartile range: 22.3-28.3) kcal/kg/day and 2.25 (interquartile range: 2.25-2.77) g/kg/day of protein using IBW in patients with obesity and actual weight in patients without obesity. Patients received 83% of energy and 63.3% of protein targets. Patients with obesity who received ≥2 g/kg IBW of protein had a significantly shorter ECMO duration (P = 0.037). Increased protein intake was independently associated with a reduced risk of death (odds ratio: 0.06; 95% confidence interval: 0.01-0.43). CONCLUSION: Higher protein intake was associated with reduced mortality. Optimal energy targets for patients receiving ECMO are currently unknown and warrant further study.

Cannula associated deep vein thromboses in COVID-19 patients supported with VV ECMO.

BACKGROUND: VV ECMO is increasingly used as a rescue strategy for hypercarbic and hypoxic respiratory failure refractory to conventional management, and more than 14,000 patients with COVID-19 related respiratory failure have been supported with VV ECMO to date. One of the known complications of VV ECMO support is the development of cannula-associated deep vein thromboses (CaDVT). The purpose of this study was to identify the incidence of CaDVT in COVID-19 patients supported with VV ECMO as compared to non-COVID-19 patients. We hypothesized that due to the hypercoagulable state and longer duration of VV ECMO support required for patients with COVID-19, a higher incidence of CaDVT would be observed in these patients. METHODS: This is a single center, retrospective observational study. About 291 non-trauma adult patients who were cannulated for VV ECMO and managed at our institution from January 1, 2014 to January 10, 2022 were included. The primary outcome was the presence of CaDVT 24 h after decannulation in COVID-19 versus non-COVID-19 patients. Our secondary outcome was continued presence of DVT on follow up imaging. CaDVT were defined as venous thrombi detected at prior cannulation sites. RESULTS: Both groups had a high incidence of CaDVT. There was no significant difference in the incidence of CaDVT in COVID-19 patients compared to non-COVID-19 patients (95% vs 88%, p = 0.13). Patients with COVID-19 had an increased incidence of persistent CaDVT on repeat imaging (78% vs 56%, p = 0.03). CONCLUSION: Given the high number of post-decannulation CaDVT in both groups, routine screening should be a part of post ECMO care in both populations. Repeat venous duplex ultrasound should be performed to assess for the need for ongoing treatment given the high incidence of CaDVT that persisted on repeat duplex scans.

High protein intake and nitrogen balance in patients receiving venovenous extracorporeal membrane oxygenation: A descriptive cohort study.

BACKGROUND: This retrospective cohort study sought to describe the ability of high protein regimens to achieve nitrogen equilibrium in patients receiving venovenous extracorporeal membrane oxygenation (VV ECMO). METHODS: Patients aged ≥18 years with a documented nitrogen balance study (NB) on VV ECMO between February 2018 and December 2021 were included. Studies with incomplete 24-h urine collections or changes in blood urea nitrogen ≥10 mg/dl were excluded. Data were summarized, correlation between first NB and potentially contributing variables was assessed with Kendall tau. Subanalysis described findings after stratifying for weight class (obese vs nonobese) and duration of VV ECMO at the time of NB. RESULTS: A total of 68 NBs in 30 patients were included; 47% of the cohort had obesity. The number of NBs per patient was 2.2 ± 1.1, which were completed on a median of 31.5 (interquartile range: 16, 53.8) days receiving ECMO. Nitrogen equilibrium or positive balance was achieved in 72% of studies despite elevated nitrogen excretion. Patients received 87.9 ± 16.8% of prescribed protein on NB days for average intakes of 2.4 ± 0.4 g/kg of actual weight per day and 2.4 ± 0.5 g/kg of ideal weight per day in patients without and with obesity. Median NB in patients without obesity was -1.46 (-8.96, 2.98) g/day and -0.21 (-10.58, 4.04) g/day in patients with obesity. A difference in median NB after stratification for timing was observed (P = 0.029). CONCLUSION: Nitrogen equilibrium can be achieved with high protein intake in adults receiving VV ECMO. NB monitoring is one tool to individualize protein prescriptions throughout the course of VV ECMO.