Hemodynamic failure and graft dysfunction after lung transplant: A possible clinical continuum with immediate and long-term consequences.

INTRODUCTION: The postoperative hemodynamic management after lung transplant (LUTX) is guided by limited evidence. We aimed to describe and evaluate risk factors and outcomes of postoperative vasoactive support of LUTX recipients. METHODS: In a single-center retrospective analysis of consecutive adult LUTX, two cohorts were identified: (1) patients needing prolonged vasoactive support (>12 h from ICU admission) (VASO+); (2) or not (VASO-). Postoperative hemodynamic characteristics were thoroughly analyzed. Risk factors and outcomes of VASO+ versus VASO- cohorts were assessed by multivariate logistic regression and propensity score matching. RESULTS: One hundred and thirty-eight patients were included (86 (62%) VASO+ versus 52 (38%) VASO-). Vasopressors (epinephrine, norepinephrine, dopamine) were used in the first postoperative days (vasoactive inotropic score at 12 h: 6 [4-12]), while inodilators (dobutamine, levosimendan) later. Length of vasoactive support was 3 [2-4] days. Independent predictors of vasoactive use were: LUTX indication different from cystic fibrosis (p = .003), higher Oto score (p = .020), longer cold ischemia time (p = .031), but not preoperative cardiac catheterization. VASO+ patients showed concomitant hemodynamic and graft impairment, with longer mechanical ventilation (p = .010), higher primary graft dysfunction (PGD) grade at 72 h (PGD grade > 0 65% vs. 31%, p = .004, OR 4.2 [1.54-11.2]), longer ICU (p < .001) and hospital stay (p = .013). Levosimendan as a second-line inodilator appeared safe. CONCLUSIONS: Vasoactive support is frequently necessary after LUTX, especially in recipients of grafts of lesser quality. Postoperative hemodynamic dysfunction requiring vasopressor support and graft dysfunction may represent a clinical continuum with immediate and long-term consequences. Further studies may elucidate if this represents a possible treatable condition.

High Doses of Inhaled Nitric Oxide as an Innovative Antimicrobial Strategy for Lung Infections.

Since the designation of nitric oxide as "Molecule of the Year" in 1992, the scientific and clinical discoveries concerning this biomolecule have been greatly expanding. Currently, therapies enhancing the release of endogenous nitric oxide or the direct delivery of the exogenous compound are recognized as valuable pharmacological treatments in several disorders. In particular, the administration of inhaled nitric oxide is routinely used to treat patients with pulmonary hypertension or refractory hypoxemia. More recently, inhaled nitric oxide has been studied as a promising antimicrobial treatment strategy against a range of pathogens, including resistant bacterial and fungal infections of the respiratory system. Pre-clinical and clinical findings have demonstrated that, at doses greater than 160 ppm, nitric oxide has antimicrobial properties and can be used to kill a broad range of infectious microorganisms. This review focused on the mechanism of action and current evidence from in vitro studies, animal models and human clinical trials of inhaled high-dose nitric oxide as an innovative antimicrobial therapy for lung infections.

Tocilizumab in patients hospitalised with COVID-19 pneumonia: Efficacy, safety, viral clearance, and antibody response from a randomised controlled trial (COVACTA).

Background: In COVACTA, a randomised, placebo-controlled trial in patients hospitalised with coronavirus disease-19 (COVID-19), tocilizumab did not improve 28-day mortality, but shortened hospital and intensive care unit stay. Longer-term effects of tocilizumab in patients with COVID-19 are unknown. Therefore, the efficacy and safety of tocilizumab in COVID-19 beyond day 28 and its impact on Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) clearance and antibody response in COVACTA were investigated. Methods: Adults in Europe and North America hospitalised with COVID-19 (N = 452) between April 3, 2020 and May 28, 2020 were randomly assigned (2:1) to double-blind intravenous tocilizumab or placebo and assessed for efficacy and safety through day 60. Assessments included mortality, time to hospital discharge, SARS-CoV-2 viral load in nasopharyngeal swab and serum samples, and neutralising anti-SARS-CoV-2 antibodies in serum. ClinicalTrials.gov registration: NCT04320615. Findings: By day 60, 24·5% (72/294) of patients in the tocilizumab arm and 25·0% (36/144) in the placebo arm died (weighted difference -0·5% [95% CI -9·1 to 8·0]), and 67·0% (197/294) in the tocilizumab arm and 63·9% (92/144) in the placebo arm were discharged from the hospital. Serious infections occurred in 24·1% (71/295) of patients in the tocilizumab arm and 29·4% (42/143) in the placebo arm. Median time to negative reverse transcriptase-quantitative polymerase chain reaction result in nasopharyngeal/oropharyngeal samples was 15·0 days (95% CI 14·0 to 21·0) in the tocilizumab arm and 21·0 days (95% CI 14·0 to 28·0) in the placebo arm. All tested patients had positive test results for neutralising anti-SARS-CoV-2 antibodies at day 60. Interpretation: There was no mortality benefit with tocilizumab through day 60. Tocilizumab did not impair viral clearance or host immune response, and no new safety signals were observed. Future investigations may explore potential biomarkers to optimize patient selection for tocilizumab treatment and combination therapy with other treatments. Funding: F. Hoffmann-La Roche Ltd and the US Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under OT number HHSO100201800036C.

Ventilation parameters and early graft function in double lung transplantation.

BACKGROUND: Currently, the primary graft dysfunction (PGD) score is used to measure allograft function in the early post-lung transplant period. Although PGD grades at later time points (T48 hours and T72 hours) are useful to predict mid- and long-term outcomes, their predictive value is less relevant within the first 24 hours after transplantation. This study aimed to evaluate the capability of PGD grades to predict prolonged mechanical ventilation (MV) and compare it with a model derived from ventilation parameters measured on arrival at the intensive care unit (ICU). METHODS: A retrospective single-center analysis of 422 double lung transplantations (LTxs) was performed. PGD was assessed 2 hours after arrival at ICU, and grades were associated with length of MV (LMV). In addition, peak inspiratory pressure (PIP), ratio of the arterial partial pressure of oxygen to fraction of inspired oxygen (P/F ratio), and dynamic compliance (cDyn) were collected, and a logistic regression model was created. The predictive capability for prolonged MV was calculated for both (the PGD score and the model). In a second step, the created model was externally validated using a prospective, international multicenter cohort including 102 patients from the lung transplant centers of Vienna, Toronto, and Budapest. RESULTS: In the retrospective cohort, a high percentage of extubated patients was reported at 24 hours (35.1%), 48 hours (68.0%), and 72 hours (80.3%) after transplantation. At T0 (time point defined as 2 hours after arrival at the ICU), patients with PGD grade 0 had a shorter LMV with a median of 26 hours (interquartile range [IQR]: 16-47 hours) than those with PGD grade 1 (median: 42 hours, IQR: 27-50 hours), PGD grade 2 (median: 37.5 hours, IQR: 15.5-78.5 hours), and PGD grade 3 (median: 46 hours, IQR: 27-86 hours). However, IQRs largely overlapped for all grades, and the value of PGD to predict prolonged MV was poor. A total of 3 ventilation parameters (PIP, cDyn, and P/F ratio), determined at T0, were chosen on the basis of clinical reasoning. A logistic regression model including these parameters predicted prolonged MV (>72 hours) with an optimism-corrected area under the curve (AUC) of 0.727. In the prospective validation cohort, the model proved to be stable and achieved an AUC of 0.679. CONCLUSIONS: The prediction model reported in this study combines 3 easily obtainable variables. It can be employed immediately after LTx to quantify the risk of prolonged MV, an important early outcome parameter.