High Mechanical Power and Driving Pressures are Associated With Postoperative Respiratory Failure Independent From Patients' Respiratory System Mechanics.

OBJECTIVES: High mechanical power and driving pressure (ΔP) have been associated with postoperative respiratory failure (PRF) and may be important parameters guiding mechanical ventilation. However, it remains unclear whether high mechanical power and ΔP merely reflect patients with poor respiratory system mechanics at risk of PRF. We investigated the effect of mechanical power and ΔP on PRF in cohorts after exact matching by patients' baseline respiratory system compliance. DESIGN: Hospital registry study. SETTING: Academic hospital in New England. PATIENTS: Adult patients undergoing general anesthesia between 2008 and 2020. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The primary exposure was high (≥ 6.7 J/min, cohort median) versus low mechanical power and the key-secondary exposure was high (≥ 15.0 cm H 2 O) versus low ΔP. The primary endpoint was PRF (reintubation or unplanned noninvasive ventilation within seven days). Among 97,555 included patients, 4,030 (4.1%) developed PRF. In adjusted analyses, high intraoperative mechanical power and ΔP were associated with higher odds of PRF (adjusted odds ratio [aOR] 1.37 [95% CI, 1.25-1.50]; p < 0.001 and aOR 1.45 [95% CI, 1.31-1.60]; p < 0.001, respectively). There was large variability in applied ventilatory parameters, dependent on the anesthesia provider. This facilitated matching of 63,612 (mechanical power cohort) and 53,260 (ΔP cohort) patients, yielding identical baseline standardized respiratory system compliance (standardized difference [SDiff] = 0.00) with distinctly different mechanical power (9.4 [2.4] vs 4.9 [1.3] J/min; SDiff = -2.33) and ΔP (19.3 [4.1] vs 11.9 [2.1] cm H 2 O; SDiff = -2.27). After matching, high mechanical power and ΔP remained associated with higher risk of PRF (aOR 1.30 [95% CI, 1.17-1.45]; p < 0.001 and aOR 1.28 [95% CI, 1.12-1.46]; p < 0.001, respectively). CONCLUSIONS: High mechanical power and ΔP are associated with PRF independent of patient's baseline respiratory system compliance. Our findings support utilization of these parameters for titrating mechanical ventilation in the operating room and ICU.

Examining the Role of Race in End-of-Life Care in the Intensive Care Unit: A Single-Center Observational Study.

Background: Prior studies have shown variation in the intensity of end-of-life care in intensive care units (ICUs) among patients of different races. Objective: We sought to identify variation in the levels of care at the end of life in the ICU and to assess for any association with race and ethnicity. Design: An observational, retrospective cohort study. Settings: A tertiary care center in Boston, MA. Participants: All critically ill patients admitted to medical and surgical ICUs between June 2019 and December 2020. Exposure: Self-identified race and ethnicity. Main Outcome and Measure: The primary outcome was death. Secondary outcomes included "code status," markers of intensity of care, consultation by the Palliative care service, and consultation by the Ethics service. Results: A total of 9083 ICU patient encounters were analyzed. One thousand two hundred fifty-nine patients (14%) died in the ICU; the mean age of patients was 64 years (standard deviation 16.8), and 44% of patients were women. A large number of decedents (22.7%) did not have their race identified. These patients had a high rate of interventions at death. Code status varied by race, with more White patients designated as "Comfort Measures Only" (CMO) (74%) whereas more Black patients were designated as "Do Not Resuscitate/Do Not Intubate (DNR/DNI) and DNR/ok to intubate" (12.1% and 15.7%) at the end of life; after adjustment for age and severity of illness, there were no statistical differences by race for the use of the CMO code status. Use of dialysis at the end of life varied by self-identified race. Specifically, Black and Unknown patients were more likely to receive renal replacement therapy, even after adjustment for age and severity of illness (24% and 20%, p = 0.003). Conclusions: Our data describe a gap in identification of race and ethnicity, as well as differences at the end of life in the ICU, especially with respect to code status and certain markers of intensity.

Mechanically Ventilated Patients With Coronavirus Disease 2019 Had a Higher Chance of In-Hospital Death If Treated With High-Flow Nasal Cannula Oxygen Before Intubation.

BACKGROUND: The impact of high-flow nasal cannula (HFNC) on outcomes of patients with respiratory failure from coronavirus disease 2019 (COVID-19) is unknown. We sought to assess whether exposure to HFNC before intubation was associated with successful extubation and in-hospital mortality compared to patients receiving intubation only. METHODS: This single-center retrospective study examined patients with COVID-19-related respiratory failure from March 2020 to March 2021 who required HFNC, intubation, or both. Data were abstracted from the electronic health record. Use and duration of HFNC and intubation were examined' as well as demographics and clinical characteristics. We assessed the association between HFNC before intubation (versus without) and chance of successful extubation and in-hospital death using Cox proportional hazards models adjusting for age, sex, race/ethnicity, obesity, hypertension, diabetes, prior chronic obstructive pulmonary disease or asthma, HCO 3 , CO 2 , oxygen-saturation-to-inspired-oxygen (S:F) ratio, pulse, respiratory rate, temperature, and length of stay before intervention. RESULTS: A total of n = 440 patients were identified, of whom 311 (70.7%) received HFNC before intubation, and 129 (29.3%) were intubated without prior use of HFNC. Patients who received HFNC before intubation had a higher chance of in-hospital death (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.06-4.05). No difference was found in the chance of successful extubation between the 2 groups (0.70, 0.41-1.20). CONCLUSIONS: Among patients with respiratory failure from COVID-19 requiring mechanical ventilation, patients receiving HFNC before intubation had a higher chance of in-hospital death. Decisions on initial respiratory support modality should weigh the risks of intubation with potential increased mortality associated with HFNC.

Anesthetics to Prevent Lung Injury in Cardiac Surgery: A Randomized Controlled Trial.

OBJECTIVES: To investigate if sevoflurane based anesthesia is superior to propofol in preventing lung inflammation and preventing postoperative pulmonary complications. DESIGN: Randomized controlled trial. SETTING: Single tertiary care university hospital. PARTICIPANTS: Forty adults undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized in a 1:1 ratio to anesthetic maintenance with sevoflurane or propofol. MEASUREMENTS AND MAIN RESULTS: Blood and bronchoalveolar lavage fluid was sampled before and after bypass to measure pulmonary inflammation using a biomarker panel. The change in bronchoalveolar lavage concentration of tumor necrosis factor alpha (TNFα) was the primary outcome. Secondary outcomes included lung inflammation defined as changes in other biomarkers and postoperative pulmonary complications. There were no significant differences between groups in the change in bronchoalveolar lavage TNFα concentration (median [IQR] change, 17.24 [1.11-536.77] v 101.51 [1.47-402.84] pg/mL, sevoflurane v propofol, p = 0.31). There was a significantly lower postbypass concentration of plasma interleukin 8 (median [IQR], 53.92 [34.5-55.91] v 66.92 [53.03-94.44] pg/mL, p = 0.04) and a significantly smaller postbypass increase in the plasma receptor for advanced glycosylation end products (median [IQR], 174.59 [73.59-446.06] v 548.22 [193.15-852.39] pg/mL, p = 0.03) in the sevoflurane group compared with propofol. The incidence of postoperative pulmonary complications was 100% in both groups, with high rates of pleural effusion (17/18 [94.44%] v 19/22 [86.36%], p = 0.39) and hypoxemia (16/18 [88.88%] v 22/22 [100%], p = 0.11). CONCLUSIONS: Sevoflurane anesthesia during cardiac surgery did not consistently prevent lung inflammation or prevent postoperative pulmonary complications compared to propofol. There were significantly lower levels of 2 plasma biomarkers specific for lung injury and inflammation in the sevoflurane group.

MUlticenter STudy of tissue plasminogen activator (alteplase) use in COVID-19 severe respiratory failure (MUST COVID): A retrospective cohort study.

Background: Few therapies exist to treat severe COVID-19 respiratory failure once it develops. Given known diffuse pulmonary microthrombi on autopsy studies of COVID-19 patients, we hypothesized that tissue plasminogen activator (tPA) may improve pulmonary function in COVID-19 respiratory failure. Methods: A multicenter, retrospective, observational study of patients with confirmed COVID-19 and severe respiratory failure who received systemic tPA (alteplase) was performed. Seventy-nine adults from seven medical centers were included in the final analysis after institutional review boards' approval; 23 were excluded from analysis because tPA was administered for pulmonary macroembolism or deep venous thrombosis. The primary outcome was improvement in the PaO2/FiO2 ratio from baseline to 48 h after tPA. Linear mixed modeling was used for analysis. Results: tPA was associated with significant PaO2/FiO2 improvement at 48 h (estimated paired difference = 23.1 ± 6.7), which was sustained at 72 h (interaction term p < 0.00). tPA administration was also associated with improved National Early Warning Score 2 scores at 24, 48, and 72 h after receiving tPA (interaction term p = 0.00). D-dimer was significantly elevated immediately after tPA, consistent with lysis of formed clot. Patients with declining respiratory status preceding tPA administration had more marked improvement in PaO2/FiO2 ratios than those who had poor but stable (not declining) respiratory status. There was one intracranial hemorrhage, which occurred within 24 h following tPA administration. Conclusions: These data suggest tPA is associated with significant improvement in pulmonary function in severe COVID-19 respiratory failure, especially in patients whose pulmonary function is in decline, and has an acceptable safety profile in this patient population.

Study of Alteplase for Respiratory Failure in SARS-CoV-2 COVID-19: A Vanguard Multicenter, Rapidly Adaptive, Pragmatic, Randomized Controlled Trial.

BACKGROUND: Pulmonary vascular microthrombi are a proposed mechanism of COVID-19 respiratory failure. We hypothesized that early administration of tissue plasminogen activator (tPA) followed by therapeutic heparin would improve pulmonary function in these patients. RESEARCH QUESTION: Does tPA improve pulmonary function in severe COVID-19 respiratory failure, and is it safe? STUDY DESIGN AND METHODS: Adults with COVID-19-induced respiratory failure were randomized from May14, 2020 through March 3, 2021, in two phases. Phase 1 (n = 36) comprised a control group (standard-of-care treatment) vs a tPA bolus (50-mg tPA IV bolus followed by 7 days of heparin; goal activated partial thromboplastin time [aPTT], 60-80 s) group. Phase 2 (n = 14) comprised a control group vs a tPA drip (50-mg tPA IV bolus, followed by tPA drip 2 mg/h plus heparin 500 units/h over 24 h, then heparin to maintain aPTT of 60-80 s for 7 days) group. Patients were excluded from enrollment if they had not undergone a neurologic examination or cross-sectional brain imaging within the previous 4.5 h to rule out stroke and potential for hemorrhagic conversion. The primary outcome was Pao2 to Fio2 ratio improvement from baseline at 48 h after randomization. Secondary outcomes included Pao2 to Fio2 ratio improvement of > 50% or Pao2 to Fio2 ratio of ≥ 200 at 48 h (composite outcome), ventilator-free days (VFD), and mortality. RESULTS: Fifty patients were randomized: 17 in the control group and 19 in the tPA bolus group in phase 1 and eight in the control group and six in the tPA drip group in phase 2. No severe bleeding events occurred. In the tPA bolus group, the Pao2 to Fio2 ratio values were significantly (P < .017) higher than baseline at 6 through 168 h after randomization; the control group showed no significant improvements. Among patients receiving a tPA bolus, the percent change of Pao2 to Fio2 ratio at 48 h (16.9% control [interquartile range (IQR), -8.3% to 36.8%] vs 29.8% tPA bolus [IQR, 4.5%-88.7%]; P = .11), the composite outcome (11.8% vs 47.4%; P = .03), VFD (0.0 [IQR, 0.0-9.0] vs 12.0 [IQR, 0.0-19.0]; P = .11), and in-hospital mortality (41.2% vs 21.1%; P = .19) did not reach statistically significant differences when compared with those of control participants. The patients who received a tPA drip did not experience benefit. INTERPRETATION: The combination of tPA bolus plus heparin is safe in severe COVID-19 respiratory failure. A phase 3 study is warranted given the improvements in oxygenation and promising observations in VFD and mortality. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT04357730; URL: www. CLINICALTRIALS: gov.

Effect of Early High-Dose Vitamin D3 Repletion on Cognitive Outcomes in Critically Ill Adults.

BACKGROUND: Long-term cognitive impairment frequently occurs after critical illness; no treatments are known to improve long-term cognition. RESEARCH QUESTION: Does a single high-dose (540,000 International Units) enteral treatment of vitamin D3 given shortly after hospital admission in critically ill patients who are vitamin D deficient improve long-term global cognition or executive function? STUDY DESIGN AND METHODS: This study evaluated long-term cognitive outcomes among patients enrolled in a multicenter, blinded, randomized clinical trial comparing vitamin D3 treatment vs placebo in critically ill adults with vitamin D deficiency. Global cognition was measured by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Executive function was measured with a composite score derived from three Delis-Kaplan Executive Function System subscales. Outcomes were assessed at a median of 443 days (interquartile range, 390-482 days) after randomization and were compared using multivariate proportional odds regression. Adjusted ORs of > 1.0 would indicate better outcomes in the vitamin D3 group compared with the placebo group. RESULTS: Ninety-five patients were enrolled, including 47 patients randomized to vitamin D3 treatment and 48 patients randomized to placebo. The adjusted median RBANS score at follow-up was 79.6 (95% CI, 73.0-84.0) in the vitamin D3 group and 82.1 (95% CI, 74.7-84.6) in the placebo group (adjusted OR, 0.83; 95% CI, 0.50-1.38). The adjusted median executive function composite scores were 8.1 (95% CI, 6.8-9.0) and 8.7 (95% CI, 7.4-9.3), respectively (adjusted OR, 0.72; 95% CI, 0.36-1.42). INTERPRETATION: In vitamin D-deficient, critically-ill adults, a large dose of enteral vitamin D3 did not improve long-term global cognition or executive function. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03733418; URL: www.clinicaltrials.gov.

Recall of clinical trial participation and attrition rates in survivors of acute respiratory distress syndrome.

PURPOSE: To measure the rate of recall of study participation and study attrition in survivors of acute respiratory distress syndrome(ARDS). MATERIALS/METHODS: In this ancillary study of the Re-evaluation of Systemic Early neuromuscular blockade(ROSE) trial, we measured the rate of study participation recall 3 months following discharge and subsequent study attrition at 6 months. We compared patient and hospital characteristics, and long-term outcomes by recall. As surrogate decision-makers provided initial consent, we measured the rate of patient reconsent and its association with study recall. RESULTS: Of 487 patients evaluated, recall status was determined in 386(82.7%). Among these, 287(74.4%) patients recalled participation in the ROSE trial, while 99(25.6%) did not. There was no significant difference in 6-month attrition among patients who recalled study participation (9.1%) and those who did not (12.1%) (p = 0.38). Patient characteristics were similar between groups, except SOFA scores, ventilator-free days, and length of stay. 330(68%) were reconsented. Compared to those not reconsented, significantly more patients who were reconsented recalled study participation(78% vs. 66%;p = 0.01). CONCLUSIONS: One in 4 ARDS survivors do not recall their participation in a clinical trial during hospitalization 3 months following hospital discharge, which did not influence 6-month attrition. However, more patients recall study participation if reconsent is obtained.

Predicting mortality in adults with suspected infection in a Rwandan hospital: an evaluation of the adapted MEWS, qSOFA and UVA scores.

RATIONALE: Mortality prediction scores are increasingly being evaluated in low and middle income countries (LMICs) for research comparisons, quality improvement and clinical decision-making. The modified early warning score (MEWS), quick Sequential (Sepsis-Related) Organ Failure Assessment (qSOFA), and Universal Vital Assessment (UVA) score use variables that are feasible to obtain, and have demonstrated potential to predict mortality in LMIC cohorts. OBJECTIVE: To determine the predictive capacity of adapted MEWS, qSOFA and UVA in a Rwandan hospital. DESIGN, SETTING, PARTICIPANTS AND OUTCOME MEASURES: We prospectively collected data on all adult patients admitted to a tertiary hospital in Rwanda with suspected infection over 7 months. We calculated an adapted MEWS, qSOFA and UVA score for each participant. The predictive capacity of each score was assessed including sensitivity, specificity, positive and negative predictive value, OR, area under the receiver operating curve (AUROC) and performance by underlying risk quartile. RESULTS: We screened 19 178 patient days, and enrolled 647 unique patients. Median age was 35 years, and in-hospital mortality was 18.1%. The proportion of data missing for each variable ranged from 0% to 11.7%. The sensitivities and specificities of the scores were: adapted MEWS >4, 50.4% and 74.9%, respectively; qSOFA >2, 24.8% and 90.4%, respectively; and UVA >4, 28.2% and 91.1%, respectively. The scores as continuous variables demonstrated the following AUROCs: adapted MEWS 0.69 (95% CI 0.64 to 0.74), qSOFA 0.65 (95% CI 0.60 to 0.70), and UVA 0.71 (95% CI 0.66 to 0.76); there was no statistically significant difference between the discriminative capacities of the scores. CONCLUSION: Three scores demonstrated a modest ability to predict mortality in a prospective study of inpatients with suspected infection at a Rwandan tertiary hospital. Careful consideration must be given to their adequacy before using them in research comparisons, quality improvement or clinical decision-making.

Reverse Trigger Phenotypes in Acute Respiratory Distress Syndrome.

Rationale: Reverse triggering is an underexplored form of dyssynchrony with important clinical implications in patients with acute respiratory distress syndrome.Objectives: This retrospective study identified reverse trigger phenotypes and characterized their impacts on Vt and transpulmonary pressure.Methods: Fifty-five patients with acute respiratory distress syndrome on pressure-regulated ventilator modes were included. Four phenotypes of reverse triggering with and without breath stacking and their impact on lung inflation and deflation were investigated.Measurements and Main Results: Inflation volumes, respiratory muscle pressure generation, and transpulmonary pressures were determined and phenotypes differentiated using Campbell diagrams of respiratory activity. Reverse triggering was detected in 25 patients, 15 with associated breath stacking, and 13 with stable reverse triggering consistent with respiratory entrainment. Phenotypes were associated with variable levels of inspiratory effort (mean 4-10 cm H2O per phenotype). Early reverse triggering with early expiratory relaxation increased Vts (88 [64-113] ml) and inspiratory transpulmonary pressures (3 [2-3] cm H2O) compared with passive breaths. Early reverse triggering with delayed expiratory relaxation increased Vts (128 [86-170] ml) and increased inspiratory and mean-expiratory transpulmonary pressure (7 [5-9] cm H2O and 5 [4-6] cm H2O). Mid-cycle reverse triggering (initiation during inflation and maximal effort during deflation) increased Vt (51 [38-64] ml), increased inspiratory and mean-expiratory transpulmonary pressure (3 [2-4] cm H2O and 3 [2-3] cm H2O), and caused incomplete exhalation. Late reverse triggering (occurring exclusively during exhalation) increased mean expiratory transpulmonary pressure (2 [1-2] cm H2O) and caused incomplete exhalation. Breath stacking resulted in large delivered volumes (176 [155-197] ml).Conclusions: Reverse triggering causes variable physiological effects, depending on the phenotype. Differentiation of phenotype effects may be important to understand the clinical impacts of these events.

Intraoperative Oxygen Concentration and Neurocognition after Cardiac Surgery.

BACKGROUND: Despite evidence suggesting detrimental effects of perioperative hyperoxia, hyperoxygenation remains commonplace in cardiac surgery. Hyperoxygenation may increase oxidative damage and neuronal injury leading to potential differences in postoperative neurocognition. Therefore, this study tested the primary hypothesis that intraoperative normoxia, as compared to hyperoxia, reduces postoperative cognitive dysfunction in older patients having cardiac surgery. METHODS: A randomized double-blind trial was conducted in patients aged 65 yr or older having coronary artery bypass graft surgery with cardiopulmonary bypass. A total of 100 patients were randomized to one of two intraoperative oxygen delivery strategies. Normoxic patients (n = 50) received a minimum fraction of inspired oxygen of 0.35 to maintain a Pao2 above 70 mmHg before and after cardiopulmonary bypass and between 100 and 150 mmHg during cardiopulmonary bypass. Hyperoxic patients (n = 50) received a fraction of inspired oxygen of 1.0 throughout surgery, irrespective of Pao2 levels. The primary outcome was neurocognitive function measured on postoperative day 2 using the Telephonic Montreal Cognitive Assessment. Secondary outcomes included neurocognitive function at 1, 3, and 6 months, as well as postoperative delirium, mortality, and durations of mechanical ventilation, intensive care unit stay, and hospital stay. RESULTS: The median age was 71 yr (interquartile range, 68 to 75), and the median baseline neurocognitive score was 17 (16 to 19). The median intraoperative Pao2 was 309 (285 to 352) mmHg in the hyperoxia group and 153 (133 to 168) mmHg in the normoxia group (P < 0.001). The median Telephonic Montreal Cognitive Assessment score on postoperative day 2 was 18 (16 to 20) in the hyperoxia group and 18 (14 to 20) in the normoxia group (P = 0.42). Neurocognitive function at 1, 3, and 6 months, as well as secondary outcomes, were not statistically different between groups. CONCLUSIONS: In this randomized controlled trial, intraoperative normoxia did not reduce postoperative cognitive dysfunction when compared to intraoperative hyperoxia in older patients having cardiac surgery. Although the optimal intraoperative oxygenation strategy remains uncertain, the results indicate that intraoperative hyperoxia does not worsen postoperative cognition after cardiac surgery.

Study of alteplase for respiratory failure in severe acute respiratory syndrome coronavirus 2/COVID-19: Study design of the phase IIa STARS trial.

Background: The coronavirus disease 2019 (COVID-19) pandemic has caused a large surge of acute respiratory distress syndrome (ARDS). Prior phase I trials (non-COVID-19) demonstrated improvement in pulmonary function in patients ARDS using fibrinolytic therapy. A follow-up trial using the widely available tissue-type plasminogen activator (t-PA) alteplase is now needed to assess optimal dosing and safety in this critically ill patient population. Objective: To describe the design and rationale of a phase IIa trial to evaluate the safety and efficacy of alteplase treatment for moderate/severe COVID-19-induced ARDS. Patients/Methods: A rapidly adaptive, pragmatic, open-label, randomized, controlled, phase IIa clinical trial will be conducted with 3 groups: intravenous alteplase 50 mg, intravenous alteplase 100 mg, and control (standard-of-care). Inclusion criteria are known/suspected COVID-19 infection with PaO2/FiO2 ratio <150 mm Hg for > 4 hours despite maximal mechanical ventilation management. Alteplase will be delivered through an initial bolus of 50 mg or 100 mg followed by heparin infusion for systemic anticoagulation, with alteplase redosing if there is a >20% PaO2/FiO2 improvement not sustained by 24 hours. Results: The primary outcome is improvement in PaO2/FiO2 at 48 hours after randomization. Other outcomes include ventilator- and intensive care unit-free days, successful extubation (no reintubation ≤3 days after initial extubation), and mortality. Fifty eligible patients will be enrolled in a rapidly adaptive, modified stepped-wedge design with 4 looks at the data. Conclusion: Findings will provide timely information on the safety, efficacy, and optimal dosing of t-PA to treat moderate/severe COVID-19-induced ARDS, which can be rapidly adapted to a phase III trial (NCT04357730; FDA IND 149634).

Fibrinolytic therapy for refractory COVID-19 acute respiratory distress syndrome: Scientific rationale and review.

The coronavirus disease 2019 (COVID-19) pandemic has caused respiratory failure and associated mortality in numbers that have overwhelmed global health systems. Thrombotic coagulopathy is present in nearly three quarters of patients with COVID-19 admitted to the intensive care unit, and both the clinical picture and pathologic findings are consistent with microvascular occlusive phenomena being a major contributor to their unique form of respiratory failure. Numerous studies are ongoing focusing on anticytokine therapies, antibiotics, and antiviral agents, but none to date have focused on treating the underlying thrombotic coagulopathy in an effort to improve respiratory failure in COVID-19. There are animal data and a previous human trial demonstrating a survival advantage with fibrinolytic therapy to treat acute respiratory distress syndrome. Here, we review the extant and emerging literature on the relationship between thrombotic coagulopathy and pulmonary failure in the context of COVID-19 and present the scientific rationale for consideration of targeting the coagulation and fibrinolytic systems to improve pulmonary function in these patients.

Rescue therapy for severe COVID-19-associated acute respiratory distress syndrome with tissue plasminogen activator: A case series.

The coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented stresses on modern medical systems, overwhelming the resource infrastructure in numerous countries while presenting a unique series of pathophysiologic clinical findings. Thrombotic coagulopathy is common in critically ill patients suffering from COVID-19, with associated high rates of respiratory failure requiring prolonged periods of mechanical ventilation. Here, we report a case series of five patients suffering from profound, medically refractory COVID-19-associated respiratory failure who were treated with fibrinolytic therapy using tissue plasminogen activator (tPA; alteplase). All five patients appeared to have an improved respiratory status following tPA administration: one patient had an initial marked improvement that partially regressed after several hours, one patient had transient improvements that were not sustained, and three patients had sustained clinical improvements following tPA administration. LEVEL OF EVIDENCE: Therapeutic, Level V.

Salvage use of tissue plasminogen activator (tPA) in the setting of acute respiratory distress syndrome (ARDS) due to COVID-19 in the USA: a Markov decision analysis.

BACKGROUND: COVID-19 threatens to quickly overwhelm our existing critical care infrastructure in the USA. Systemic tissue plasminogen activator (tPA) has been previously demonstrated to improve PaO2/FiO2 (mmHg) when given to critically ill patients with acute respiratory distress syndrome (ARDS). It is unclear to what extent tPA may impact population-based survival during the current US COVID-19 pandemic. METHODS: A decision analytic Markov state transition model was created to simulate the life critically ill COVID-19 patients as they transitioned to either recovery or death. Two patient groups were simulated (50,000 patients in each group); (1) Patients received tPA immediately upon diagnosis of ARDS and (2) patients received standard therapy for ARDS. Base case critically ill COVID-19 patients were defined as having a refractory PaO2/FiO2 of < 60 mmHg (salvage use criteria). Transition from severe to moderate to mild ARDS, recovery, and death were estimated. Markov model parameters were extracted from existing ARDS/COVID-19 literature. RESULTS: The use of tPA was associated with reduced mortality (47.6% [tTPA] vs. 71.0% [no tPA]) for base case patients. When extrapolated to the projected COVID-19 eligible for salvage use tPA in the USA, peak mortality (deaths/100,000 patients) was reduced for both optimal social distancing (70.5 [tPA] vs. 75.0 [no tPA]) and no social distancing (158.7 [tPA] vs. 168.8 [no tPA]) scenarios. CONCLUSIONS: Salvage use of tPA may improve recovery of ARDS patients, thereby reducing COVID-19-related mortality and ensuring sufficient resources to manage this pandemic.

The Association between Prehospital Vulnerability, ARDS Development, and Mortality among At-Risk Adults. Results from the LIPS-A Clinical Trial.

Rationale: No previous studies have examined the role of prehospital vulnerability in acute respiratory distress syndrome (ARDS) development and mortality in an acutely ill adult population.Objectives: To describe the association between prehospital vulnerability and 1) the development of ARDS, 2) 28-day mortality, and 3) 1-year mortality.Methods: This was a longitudinal prospective cohort study nested within the multicenter LIPS-A (Lung Injury Prevention Study-Aspirin) trial. We analyzed 301 participants who completed Vulnerable Elders Survey (VES) at baseline. Multivariable logistic regression and Cox regression analyses were used to describe the association between vulnerability and short-term outcomes (ARDS and 28-day mortality) and long-term outcomes (1-year mortality), respectively.Results: The VES score ranged from 0 to 10 (median [interquartile range], 2.0 [0-6]); 143 (47.5%) fit criteria for prehospital vulnerability (VES ≥ 3). Vulnerability was not significantly associated with ARDS development (10 [7.0%] vulnerable patients developed ARDS as per LIPS-A study criteria vs. 20 [12.7%] without vulnerability; P = 0.10; adjusted odds ratio [95% confidence interval (CI)], 0.54 [0.24-1.24]; P = 0.15). Nor was vulnerability associated with 28-day mortality (15 [10.5%] vulnerable patients were dead by Day 28 vs. 11 [7.0%] nonvulnerable patients; P = 0.28; adjusted odds ratio [95% CI], 0.95 [0.39-2.26]; P = 0.90). Vulnerability was significantly associated with 1-year mortality in hospital survivors (35 [26.9%] vs. 13 [9.3%]; adjusted hazard ratio [95% CI], 2.20 [1.10-4.37]; P = 0.02).Conclusions: In a population of adults recruited for their high risk of ARDS, prehospital vulnerability, measured by VES, was highly prevalent and strongly associated with 1-year mortality.

The "Just Right" Amount of Oxygen. Improving Oxygen Use in a Rwandan Emergency Department.

Rationale: Despite oxygen's classification as an essential medication by the World Health Organization, it is inconsistently available in many resource-constrained settings. Hypoxemia is associated with increased mortality, and mounting evidence suggests that hyperoxia may also be associated with adverse outcomes.Objectives: To determine if overuse of oxygen for some patients in a Rwandan tertiary care hospital emergency department might coexist with oxygen shortages and underuse of oxygen for other patients, and whether an educational intervention coupled with provision of pulse oximeters could improve the distribution of limited oxygen resources.Methods: We screened all patients in the adult emergency department (ED) of the University Teaching Hospital of Kigali for hypoxemia and receipt of oxygen therapy for 5 weeks. After completing baseline data collection, we provided pulse oximeters and conducted a didactic training with pre- and posttests on oxygen titration, with a chosen target oxygen saturation (SpO2) of 90% to 95%. Four and 12 weeks after the intervention, we evaluated all patients in the ED again for SpO2 and receipt of oxygen therapy for 4 weeks each period. We also recorded ED oxygen use and availability of reserve oxygen for the hospital during the three study periods.Results: During all data collection periods, 214 of 1,765 (12.1%) unique patients screened were hypoxemic. The proportion of patient-days with appropriately titrated oxygen therapy (SpO2, 90-95%) increased from 18.7% at baseline to 38.5% and 42.0% at 4 and 12 weeks postintervention (P < 0.001). On a multiple-choice examination testing knowledge of appropriate oxygen titration, clinicians' scores improved from average 60% (interquartile range [IQR], 40-80%) correct to 80% (IQR, 60-80%) correct immediately after the educational intervention (P < 0.001). Oxygen use in the ED decreased from a median of 32.0 (IQR, 28.0-35.0) tanks per day to 25.5 (IQR, 24.0-29.0) and 16.0 (IQR, 12.5-21.0) tanks per day at Weeks 4 and 12, respectively (P < 0.001), and the median daily number of tanks in reserve for the hospital appeared to increase, although this did not reach statistical significance (30.0 [IQR, 9.0-46.0], 86.5 [IQR, 74.0-92.0], and 75.5 [IQR, 8.5-88.5], respectively; P = 0.07).Conclusions: Among patients in a Rwandan adult ED, 12.1% of patients were hypoxemic and 81.3% of patient-days were either under- or overtreated with oxygen during baseline data collection on the basis of our defined target of SpO2 90% to 95%. Follow-up results at 4 and 12 weeks postintervention demonstrated sustained improvement in oxygen titration and likely increased availability of oxygen resources.