Carbon Dioxide Targets in Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome.

Target values for arterial carbon dioxide tension (PaCO2) in extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) are unknown. We hypothesized that lower PaCO2 values on ECMO would be associated with lighter sedation. We used data from two independent patient cohorts with ARDS spending 1,177 days (discovery cohort, 69 patients) and 516 days (validation cohort, 70 patients) on ECMO and evaluated the associations between daily PaCO2, pH, and bicarbonate (HCO3) with sedation. Median PaCO2 was 41 (interquartile range [IQR] = 37-46) mm Hg and 41 (IQR = 37-45) mm Hg in the discovery and the validation cohort, respectively. Lower PaCO2 and higher pH but not bicarbonate (HCO3) served as significant predictors for reaching a Richmond Agitation Sedation Scale (RASS) target range of -2 to +1 (lightly sedated to restless). After multivariable adjustment for mortality, tracheostomy, prone positioning, vasoactive inotropic score, Simplified Acute Physiology Score (SAPS) II or Sequential Organ Failure Assessment (SOFA) Score and day on ECMO, only PaCO2 remained significantly associated with the RASS target range (adjusted odds ratio 1.1 [95% confidence interval (CI) = 1.01-1.21], p = 0.032 and 1.29 [95% CI = 1.1-1.51], p = 0.001 per mm Hg decrease in PaCO2 for the discovery and the validation cohort, respectively). A PaCO2 ≤40 mm Hg, as determined by the concordance probability method, was associated with a significantly increased probability of a sedation level within the RASS target range in both patient cohorts (adjusted odds ratio = 2.92 [95% CI = 1.17-7.24], p = 0.021 and 6.82 [95% CI = 1.50-31.0], p = 0.013 for the discovery and the validation cohort, respectively).

External Validation of the PREdiction of Survival on Extracorporeal Membrane Oxygenation Therapy (PRESET) Score: A Single Center Cohort Experience.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition affecting >10% of intensive care unit (ICU) patients worldwide with a mortality of up to 59% depending on severity. Extracorporeal membrane oxygenation (ECMO) is a potentially life-saving procedure in severe ARDS but is technically and financially challenging. In recent years, various scoring systems have been proposed to select patients most likely to benefit from ECMO, with the PREdiction of Survival on ECMO Therapy (PRESET) score being one of the most used. We collected data from 283 patients with ARDS of various etiology who underwent veno-venous (V-V) ECMO therapy at a German tertiary care ICU from January 2012 to December 2022. Median age in the cohort was 56 years, and 64.31% were males. The in-hospital mortality rate was 50.88% (n = 144). The median (25%; 75% quartile) severity scores were 38 (31; 49) for Simplified Acute Physiology Score (SAPS) II, 12 (10; 13) for Sequential Organ Failure Assessment (SOFA) and 7 (5; 8) for PRESET. Simplified Acute Physiology Score-II displayed the best prognostic value (area under the receiver operating characteristic [AUROC]: 0.665 [confidence interval (CI): 0.574-0.756; p = 0.046]). Prediction performance was weak in all analyzed scores despite good calibration. Simplified Acute Physiology Score-II had the best discrimination after adjustment of our original cohort. The use of scores explored in this study for patient selection for eligibility for V-V ECMO is not recommendable.

Transfer of Veno-venous Extracorporeal Membrane Oxygenation Patients With COVID-19 Associated Acute Respiratory Distress Syndrome.

Interhospital transport of acute respiratory distress syndrome (ARDS) patients bears transport-associated risks. It is unknown how interhospital extracorporeal membrane oxygenation (ECMO) transfer of COVID-19 patients by mobile ECMO units affects ARDS mortality. We compared the outcome of 94 COVID-19 patients cannulated in primary care hospitals and retrieved by mobile ECMO-teams to that of 84 patients cannulated at five German ECMO centers. Patients were recruited from March 2020 to November 2021. Twenty-six transports were airborne, 68 were land-based. Age, sex, body-mass-index, Simplified Acute Physiology Score (SAPS) II, days invasively ventilated, and P/F-Ratio before ECMO initiation were similar in both groups. Counting only regional transports (≤250 km), mean transport distance was 139.5 km ± 17.7 km for helicopter (duration 52.5 ± 10.6 minutes) and 69.8 km ± 44.1 km for ambulance or mobile intensive care unit (duration 57.6 ± 29.4 minutes). Overall time of vvECMO support (20.4 ± 15.2 ECMO days for transported patients vs. 21.0 ± 20.5 for control, p = 0.83) and days invasively ventilated (27.9 ± 18.1 days vs. 32.6 ± 25.1 days, p = 0.16) were similar. Overall mortality did not differ between transported patients and controls (57/94 [61%] vs. 51/83 [61%], p = 0.43). COVID-19 patients cannulated and retrieved by mobile ECMO-teams have no excess risk compared with patients receiving vvECMO at experienced ECMO centers. Patients with COVID-19-associated ARDS, limited comorbidities, and no contraindication for ECMO should be referred early to local ECMO centers.

Daratumumab for a Patient With Refractory Antineutrophil Cytoplasmatic Antibody-Associated Vasculitis.

This case reports on a patient with antineutrophil cytoplasmatic antibody­associated vasculitis and severe pulmonary and cutaneous involvement who received conventional therapy that failed and who was rescued by daratumumab therapy.

Respiratory Physiology of COVID-19 and Influenza Associated Acute Respiratory Distress Syndrome.

Background: There is ongoing debate whether lung physiology of COVID-19-associated acute respiratory distress syndrome (ARDS) differs from ARDS of other origin. Objective: The aim of this study was to analyze and compare how critically ill patients with COVID-19 and Influenza A or B were ventilated in our tertiary care center with or without extracorporeal membrane oxygenation (ECMO). We ask if acute lung failure due to COVID-19 requires different intensive care management compared to conventional ARDS. Methods: 25 patients with COVID-19-associated ARDS were matched to a cohort of 25 Influenza patients treated in our center from 2011 to 2021. Subgroup analysis addressed whether patients on ECMO received different mechanical ventilation than patients without extracorporeal support. Results: Compared to Influenza-associated ARDS, COVID-19 patients had higher ventilatory system compliance (40.7 mL/mbar [31.8-46.7 mL/mbar] vs. 31.4 mL/mbar [13.7-42.8 mL/mbar], p = 0.198), higher ventilatory ratio (1.57 [1.31-1.84] vs. 0.91 [0.44-1.38], p = 0.006) and higher minute ventilation at the time of intubation (mean minute ventilation 10.7 L/min [7.2-12.2 L/min] for COVID-19 vs. 6.0 L/min [2.5-10.1 L/min] for Influenza, p = 0.013). There were no measurable differences in P/F ratio, positive end-expiratory pressure (PEEP) and driving pressures (ΔP). Respiratory system compliance deteriorated considerably in COVID-19 patients on ECMO during 2 weeks of mechanical ventilation (Crs, mean decrease over 2 weeks -23.87 mL/mbar ± 32.94 mL/mbar, p = 0.037) but not in ventilated Influenza patients on ECMO and less so in ventilated COVID-19 patients without ECMO. For COVID-19 patients, low driving pressures on ECMO were strongly correlated to a decline in compliance after 2 weeks (Pearson's R 0.80, p = 0.058). Overall mortality was insignificantly lower for COVID-19 patients compared to Influenza patients (40% vs. 48%, p = 0.31). Outcome was insignificantly worse for patients requiring veno-venous ECMO in both groups (50% mortality for COVID-19 on ECMO vs. 27% without ECMO, p = 0.30/56% vs. 34% mortality for Influenza A/B with and without ECMO, p = 0.31). Conclusion: The pathophysiology of early COVID-19-associated ARDS differs from Influenza-associated acute lung failure by sustained respiratory mechanics during the early phase of ventilation. We question whether intubated COVID-19 patients on ECMO benefit from extremely low driving pressures, as this appears to accelerate derecruitment and consecutive loss of ventilatory system compliance.