The PaCO2/FiO2 ratio as outcome predictor in SARS-COV-2 related pneumonia: a retrospective study.

BACKGROUND AND AIM: Respiratory failure in SARS-CoV-2 patients is characterized by the presence of hypoxemia and hypocapnia without relevant dyspnea. To date, the use of respiratory parameters other than PaO2/FiO2 ratio to stratify the risk of worsening of these patients has not been sufficiently studied.  Aim of this work was to evaluate whether the ratio between partial pressure levels of carbon dioxide (PaCO2) and the fraction of inspired oxygen (FiO2) measured at emergency department (ED) admission is predictive of the clinical course of patients suffering from SARS-CoV-2 pneumonia. METHODS: We retrospectively studied 236 patients with SARS-CoV-2 pneumonia evaluated at the ED of the Perugia Hospital. The end-points were: in-hospital mortality, need for invasive mechanical ventilation (IMV) and length of in-hospital stay (LOS). Clinical, blood gas and laboratory data were collected at ED admission. RESULTS: Of the 236 patients 157 were male, the mean age was 64 ± 16. Thirtythree patients (14%) needed IMV, 49 died (21%). In the univariate analysis, the PaCO2/FiO2 ratio was inversely associated with the need for IMV (p <0.001), mortality (p <0.001) and LOS (p = 0.005). At the multivariate analysis the PaCO2/FiO2 ratio was found to be predictive of the need for IMV, independently from age, gender, number of comorbidities, neutrophils, lymphocytes, glomerular filtrate, d-dimer, LDH and CRP. CONCLUSIONS: the PaCO2/FiO2 ratio is predictive of the risk of respiratory failure worsening in patients with SARS-CoV-2 pneumonia, independently from other several confounding factors.

High-flow nasal therapy versus noninvasive ventilation in COPD patients with mild-to-moderate hypercapnic acute respiratory failure: study protocol for a noninferiority randomized clinical trial.

BACKGROUND: Noninvasive ventilation (NIV) is indicated to treat respiratory acidosis due to exacerbation of chronic obstructive pulmonary disease (COPD). Recent nonrandomized studies also demonstrated some physiological effects of high-flow nasal therapy (HFNT) in COPD patients. We designed a prospective, unblinded, multicenter, randomized controlled trial to assess the noninferiority of HFNT compared to NIV with respect to the reduction of arterial partial pressure of carbon dioxide (PaCO2) in patients with hypercapnic acute respiratory failure with mild-to-moderate respiratory acidosis. METHODS: We will enroll adult patients with acute hypercapnic respiratory failure, as defined by arterial pH between 7.25 and 7.35 and PaCO2 ≥ 55 mmHg. Patients will be randomly assigned 1:1 to receive NIV or HFNT. NIV will be applied through a mask with a dedicated ventilator in pressure support mode. Positive end-expiratory pressure will be set at 3-5 cmH2O with inspiratory support to obtain a tidal volume between 6 and 8 ml/kg of ideal body weight. HFNT will be initially set at a temperature of 37 °C and a flow of 60 L/min. At 2 and 6 h we will assess arterial blood gases, vital parameters, respiratory rate, treatment intolerance and failure, need for endotracheal intubation, time spent under mechanical ventilation (both invasive and NIV), intensive care unit and hospital length of stay, and hospital mortality. Based on an α error of 5% and a ß error of 80%, with a standard deviation for PaCO2 equal to 15 mmHg and a noninferiority limit of 10 mmHg, we computed a sample size of 56 patients. Considering potential drop-outs and nonparametric analysis, the final computed sample size was 80 patients (40 per group). DISCUSSION: HFNT is more comfortable than NIV in COPD patients recovering from an episode of exacerbation. If HFNT would not be inferior to NIV, HFNT could be considered as an alternative to NIV to treat COPD patients with mild-to-moderate respiratory acidosis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03370666 . Registered on December 12, 2017.

Incidence of chronic thromboembolic pulmonary hypertension after a first episode of pulmonary embolism.

STUDY OBJECTIVE: To assess the incidence of chronic thromboembolic pulmonary hypertension (CTPH) after the first episode of objectively confirmed pulmonary embolism (PE). DESIGN: Prospective cohort study in 12 Italian medical centers. PATIENTS: Consecutive patients treated with oral anticoagulants for the first episode of PE, either idiopathic or associated with temporary risk factors, were followed up for at least 3 years. Patients were excluded from the study if they had a known persistent risk factor for venous thromboembolism (VTE). INTERVENTIONS: At the follow-up visits, patients were evaluated for persistent dyspnea, either at rest or on exertion. All patients who were referred with dyspnea were assessed by transthoracic echocardiography, with evaluation of the systolic and mean pulmonary artery pressures. Patients with evidence of pulmonary hypertension on echocardiography underwent perfusion lung scans and pulmonary angiography to confirm the diagnosis of CTPH. RESULTS: Overall, 259 patients were included in the study. PE was idiopathic in 135 patients, while it was associated with at least a temporary risk factor for VTE in 124 patients. After an average follow-up period of 46 months, 37 patients were found to have persistent dyspnea that was unexplained in 5 patients. Among these patients, a diagnosis of CTPH was confirmed in two patients with idiopathic PE (0.8% of the overall study population [95% confidence interval (CI), 0.0 to 1.9]; 1.5% of patients with idiopathic PE [95% CI, 0.0 to 3.6]). The diagnosis was made 14 and 22 months, respectively, after the acute PE. CONCLUSIONS: The incidence of CTPH observed in this study was about 1%. CTPH was observed in two patients with idiopathic PE.

Interactions between thrombophilic genetic mutations and clinical bleeding in patients on chronic oral anticoagulant treatment.

We studied the prevalence of genetic thrombophilic mutations in patients on chronic oral anticoagulant treatment (OAT) who had bleeding complications. In a case-control study we found ten (12.8%) carriers of factor V Leiden and two (2.5%) carriers of the PT20210A mutation among 78 patients with a history of moderate-severe bleeding while on OAT, and seven (4.4%) and four (2.5%), respectively, among 156 matched patients with no bleeding while on OAT (odds ratio 3.1+/-1.6, p=0.026). In patients on chronic OAT, FV Leiden is a risk factor for moderate-severe bleeding.

Thrombophilic abnormalities and recurrence of venous thromboembolism in patients treated with standardized anticoagulant treatment.

INTRODUCTION: Whether patients with hereditary or acquired thrombophilia have an increased risk for recurrence of venous thromboembolism (deep vein thrombosis and/or pulmonary embolism) is still controversial. The aim of this study was to evaluate the incidence of recurrence of venous thromboembolism in patients with and without thrombophilic abnormalities treated with standardized anticoagulant treatment. MATERIAL AND METHODS: Database was from a prospective multicenter randomized study aimed at evaluating the long-term clinical benefit of extending to 1 year the 3-month oral anticoagulant treatment after a first episode of idiopathic proximal deep vein thrombosis. The screening for thrombophilia included antithrombin, protein C, protein S deficiencies, resistance to activated protein C and/or factor V R506Q mutation, the mutation 20210GA of the prothrombin gene, hyperhomocysteinemia and antiphospholipid antibodies. The diagnosis of venous thromboembolism recurrence was done by objective tests and adjudicated by a panel unaware of the results of the thrombophilia screening. RESULTS: A screening for thrombophilic abnormalities was performed in 195 patients. Twenty of 57 (35.1%) thrombophilic patients experienced a recurrence of venous thromboembolism as compared with 29 of 138 (21.0%) patients without thrombophilia (HR=1.78, 95% CI 1.002-3.140, p=0.046). The difference in VTE recurrence between patients with and without thrombophilia was accounted for by those who received 3 months of oral anticoagulation (HR=3.21, 95% CI 1.349-7.616, p=0.008). No difference between thrombophilic and non-thrombophilic patients was observed in the time interval from the index episode to recurrent venous thromboembolism (29.1+/-23.9 and 30.6+/-19.8 months, respectively). CONCLUSIONS: Thrombophilic abnormalities are associated with an increased risk of venous thromboembolism recurrence. The role of thrombophilia in the long-term management of venous thromboembolism should be addressed in prospective management studies.

A prospective study on cardiovascular events after acute pulmonary embolism.

AIMS: To evaluate the incidence of cardiovascular events in the long-term clinical course of patients with a first episode of symptomatic, objectively confirmed pulmonary embolism. METHODS AND RESULTS: Three hundred and sixty patients with a first episode of pulmonary embolism were included in a prospective study: 209 with idiopathic pulmonary embolism and 151 with pulmonary embolism associated with transient risk factors. The study outcomes were cardiovascular events (recurrent venous thrombo-embolism, acute myocardial infarction, stroke, sudden otherwise unexplained death), cardiovascular death, and death due to any cause. The median follow-up was 38 months. Sixty-four patients had at least one cardiovascular event (5.5% patient-year). Recurrent venous thrombo-embolism occurred in 45 patients (3.9% patient-year), acute myocardial infarction in 12 patients (1.0% patient-year), stroke in six patients (0.5% patient-year), and sudden otherwise unexplained death in four patients (0.3% patient-year). A cardiovascular event occurred in 47 patients with idiopathic pulmonary embolism (7.5% patient-year) and in 17 patients with pulmonary embolism associated with transient risk factors (3.1% patient-year) (RR 2.0; 95% CI 1.20-3.34; P=0.006). Twenty patients with idiopathic pulmonary embolism (3.2% patient-year) and two patients with pulmonary embolism associated with transient risk factors (0.4% patient-year) presented an arterial cardiovascular event (RR 7.2; 95% CI 1.71-30.45; P=0.001). Thirty-three patients died (9.2%). Cardiovascular mortality and cancer mortality accounted for 42.4 and 21.2% of overall mortality, respectively. Idiopathic pulmonary embolism was an independent predictor of cardiovascular events after adjusting for age. CONCLUSIONS: Cardiovascular events are more common in patients with idiopathic pulmonary embolism than in patients with pulmonary embolism associated with transient risk factors. Cardiovascular events are the major cause of death in patients with idiopathic pulmonary embolism.

Extended oral anticoagulant therapy after a first episode of pulmonary embolism.

BACKGROUND: The optimal duration of oral anticoagulant treatment after a first episode of pulmonary embolism remains uncertain. OBJECTIVE: To evaluate the long-term clinical benefit of extending a 3-month course of oral anticoagulant therapy to 6 months (pulmonary embolism associated with temporary risk factors) or to 1 year (idiopathic pulmonary embolism) in patients with a first episode of pulmonary embolism. DESIGN: Multicenter randomized study with independent, blinded assessment of the outcome events. SETTING: 19 Italian hospitals. PATIENTS: 326 patients who had had 3 months of oral anticoagulant therapy without experiencing recurrence or bleeding. MEASUREMENTS: The primary study outcome was recurrence of symptomatic, objectively confirmed venous thromboembolism. RESULTS: Among 165 patients assigned to extended anticoagulant therapy, 15 patients (9.1%) had a recurrence of venous thromboembolism (3.1% per patient-year; average follow-up, 34.9 months), as compared with 18 of 161 patients (11.2%) assigned to discontinue treatment (4.1% per patient-year; average follow-up, 32.7 months); the rate ratio was 0.81 (95% CI, 0.42 to 1.56). All but one of the recurrences occurred after anticoagulant treatment was discontinued. Nineteen recurrences (57.6%) were episodes of pulmonary embolism, two of which were fatal. Three major bleeding episodes were observed during extended anticoagulation (1.8%). Among patients with idiopathic venous thromboembolism, 11 of 90 patients assigned to extended anticoagulation and 11 of 91 patients assigned to discontinue treatment experienced a recurrence (relative risk, 0.99 [CI, 0.45 to 2.16]). CONCLUSION: Patients with pulmonary embolism have a substantial risk for recurrence after discontinuation of oral anticoagulation, regardless of treatment duration. Physicians should try to identify patients who are at high risk for recurrent venous thromboembolism and are therefore potential candidates for indefinite oral anticoagulant therapy.