The interplay of inflammation and coagulation in COVID-19 Patients receiving extracorporeal membrane oxygenation support.

OBJECTIVE: Bleeding and thrombosis are common complications during Extracorporeal Membrane Oxygenation (ECMO) support for COVID-19 patients. We sought to examine the relationship between inflammatory status, coagulation effects, and observed bleeding and thrombosis in patients receiving venovenous (VV) ECMO for COVID-19 respiratory failure. STUDY DESIGN: Cross-sectional cohort study. SETTINGS: Quaternary care institution. PATIENTS: The study period from April 1, 2020, to January 1, 2021, we included all patients with confirmed COVID-19 who received VV ECMO support. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Thirty-two patients were supported with VV ECMO during the study period, and 17 patients (53%) survived to hospital discharge. The ECMO nonsurvivors mean lactate dehydrogenase (LDH) levels were markedly elevated in comparison to survivors (1046 u/L [IQR = 509, 1305] vs 489 u/L [385 658], p = 0.003). Platelet/fibrinogen dysfunction, as reflected by the low Maximum Amplitude (MA) on viscoelastic testing, was worse in nonsurvivors (65.25 mm [60.68, 67.67] vs 74.80 mm [73.10, 78.40], p = 0.01). Time-group interaction for the first seven days of ECMO support, showed significantly lower platelet count in the nonsurvivors (140 k/ul [103, 170] vs 189.5 k/ul [ 146, 315], p < 0.001) and higher D-dimer in (21 µg/mL [13, 21] vs 14 µg/mL [3, 21], p < 0.001) in comparison to the survivors. Finally, we found profound statistically significant correlations between the clinical markers of inflammation and markers of coagulation in the nonsurvivors group. The ECMO nonsurvivors experienced higher rate of bleeding (73.3% vs 35.3%, p = 0.03), digital ischemia (46.7% vs 11.8%, p = 0.02), acute renal failure (60% vs 11.8%, p = 0.01) and bloodstream infection (60% vs 23.5%, p = 0.03). CONCLUSION: The correlation between inflammation and coagulation in the nonsurvivors supported with VV ECMO could indicate dysregulated inflammatory response and worse clinical outcomes.

Extracorporeal membrane oxygenation for COVID-19 induced hypoxia: Single-center study.

INTRODUCTION: The pandemic of the coronavirus disease 2019 (COVID-19) and associated pneumonia represent a clinical and scientific challenge. The role of Extracorporeal Membrane Oxygenation (ECMO) in such a crisis remains unclear. METHODS: We examined COVID-19 patients who were supported for acute respiratory failure by both conventional mechanical ventilation (MV) and ECMO at a tertiary care institution in Washington DC. The study period extended from March 23 to April 29. We identified 59 patients who required invasive mechanical ventilation. Of those, 13 patients required ECMO. RESULTS: Nine out of 13 ECMO (69.2%) patients were decannulated from ECMO. All-cause ICU mortality was comparable between both ECMO and MV groups (6 patients [46.15%] vs. 22 patients [47.82 %], p = 0.92). ECMO non-survivors vs survivors had elevated D-dimer (9.740 mcg/ml [4.84-20.00] vs. 3.800 mcg/ml [2.19-9.11], p = 0.05), LDH (1158 ± 344.5 units/L vs. 575.9 ± 124.0 units/L, p = 0.001), and troponin (0.4315 ± 0.465 ng/ml vs. 0.034 ± 0.043 ng/ml, p = 0.04). Time on MV as expected was significantly longer in ECMO groups (563.3 hours [422.1-613.9] vs. 247.9 hours [101.8-479] in MV group, p = 0.0009) as well as ICU length of stay 576.2 hours [457.5-652.8] in ECMO group vs. 322.2 hours [120.6-569.3] in MV group, p = 0.012). CONCLUSION: ECMO is a supportive intervention for COVID-19 associated pneumonia that could be considered if the optimum mechanical ventilation is deemed ineffective. Biomarkers such as D-dimer, LDH, and troponin could help with discerning the clinical prognosis in patients with COVID-19 pneumonia.

Impact of a Mechanical Ventilation Curriculum on Respiratory Therapist Recognition of Patient-Ventilator Asynchrony.

BACKGROUND: Respiratory therapists (RTs) play a crucial role in managing mechanically ventilated patients, such as addressing patient-ventilator asynchronies that may contribute to patient harm. Waveform analysis is integral to the evaluation of patient-ventilator asynchronies; despite this, no published studies have assessed the ability of practicing RTs to interpret ventilator waveform abnormalities. METHODS: The study took place between June 2017-February 2019. Eighty-six RTs from 2 academic medical centers enrolled in a one-day mechanical ventilation course. The scores of 79 first-time attendees were included in the analysis. Prior to and following the course, RTs were asked to identify abnormalities on a 5-question, multiple-choice ventilator waveform exam. They were also asked to provide a self-assessment of their ventilator management skills on a 1 (complete novice) to 5 (expert) scale. RESULTS: Initial scores were low but improved after one day of ventilator instruction (19.4 ± 17.1 vs 29.6 ± 19.0, P < .001). No significant difference was noted in mean confidence levels between the pre- and post-course assessments (3.8 ± 0.9 vs 3.8 ± 1.0, P = .56). RTs with fewer years of clinical experience (0-10 y) had a statistically significant improvement in their post-course test scores relative to their pre-course scores (0-5 y: 12.5 ± 10.1 to 46.0 ± 10.8, P < .001; 6-10 y: 18.7 ± 15.8 to 32.1 ± 16.7, P = .02), whereas those with > 11 y of clinical experience did not (11-20 y: 22.4 ± 15.5 to 27.4 ± 19.0, P = .44; 21+ y: 19.6 ± 22.1 to 15.3 ± 13.8, P = .50). CONCLUSIONS: RTs may benefit from additional training in ventilator waveform interpretation, especially early in their clinical training. More work is needed to determine the optimal length and content of a mechanical ventilation curriculum for RTs.

Impact of Novel Multiinstitutional Curriculum on Critical Care Fellow Ventilator Knowledge.

Background: Management of mechanical ventilation (MV) is a curricular milestone for trainees in pulmonary critical care medicine (PCCM) and critical care medicine (CCM) fellowships. Though recognition of ventilator waveform abnormalities that could result in patient complications is an important part of management, it is unclear how well fellows recognize these abnormalities.Objective: To study proficiency of ventilator waveform analysis among first-year fellows enrolled in a MV course compared with that of traditionally trained fellows.Methods: The study took place from July 2016 to January 2019, with 93 fellows from 10 fellowship programs completing the waveform examination. Seventy-three fellows participated in a course during their first year of fellowship, with part I occurring at the beginning of fellowship in July and part II occurring after 6 months of clinical work. These fellows were given a five-question ventilator waveform examination at multiple time points throughout the two-part course. Twenty fellows from three other fellowship programs who were in their first, second, or third year of fellowship and who did not participate in this course served as the control group. These fellows took the waveform examination a single time, at a median of 23 months into their training.Results: Before the course, scores were low but improved after 3 days of education at the beginning of the fellowship (18.0 ± 1.6 vs. 45.6 ± 3.0; P < 0.0001). Scores decreased after 6 months of clinical rotations but increased to their highest levels after part II of the course (33.7 ± 3.1 for part II pretest vs. 77.4 ± 2.4 for part II posttest; P < 0.0001). After completing part I at the beginning of fellowship, fellows participating in the course outperformed control fellows, who received a median of 23 months of traditional fellowship training at the time of testing (45.6 ± 3.0 vs. 25.3 ± 2.7; P < 0.0001). There was no difference in scores between PCCM and CCM fellows. In anonymous surveys, the fellows also rated the mechanical ventilator lectures highly.Conclusion: PCCM and CCM fellows do not recognize common waveform abnormalities at the beginning of fellowship but can be trained to do so. Traditional fellowship training may be insufficient to master ventilator waveform analysis, and a more intentional, structured course for MV may help fellowship programs meet the curricular milestones for MV.

The endotracheal tube cuff-leak test as a predictor for postextubation stridor.

BACKGROUND: The endotracheal tube (ETT) cuff-leak test (CLT) has been proposed as a relatively simple, noninvasive method for detecting the presence of laryngeal edema prior to tracheal extubation. OBJECTIVE: To determine the value of the CLT for predicting postextubation stridor (PES) among medical and surgical patients, and to assess the impact of certain variables on the incidence of PES. METHODS: We conducted a prospective, observational study in the intensive care unit at Washington Hospital Center, a 907-bed acute care hospital in Washington DC, with patients who were intubated for > 24 h. As part of respiratory therapy quality assurance, patients intubated for > 24 h are evaluated daily for extubation readiness, and CLT is conducted prior to extubation. The CLT results and the postextubation outcomes were prospectively recorded for 6 months. RESULTS: Of the 462 patients studied, 20 (4.3%) developed PES that required treatment; 7 of those 20 (1.5%) required reintubation. With patients who failed the CLT, defined by an absolute leak volume < or = 110 mL, the positive predictive value for PES was 0.12, the negative predictive value was 0.97, the sensitivity was 0.50, and the specificity was 0.84. Using different definitions for CLT failure did not improve the accuracy of CLT for predicting PES. Patients who had PES were more likely to be female (6.5% vs 2.4%, p = 0.04), to have a longer duration of translaryngeal intubation (6.5 + 4 d vs 4.5 + 4 d, p = 0.02), and to have a larger ratio of ETT size to laryngeal size (49.5 + 6% vs 45.5 + 6%, p = 0.01). CONCLUSIONS: Failing the CLT was not an accurate predictor of PES and should not be used as an indication for either delaying extubation or initiating other specific therapy. Female patients, those whose ratio of ETT size to laryngeal diameter was > 45%, and patients intubated for > 6 d were more likely to develop PES.