20 research outputs found
Development and validation of a prediction model for severe respiratory failure in hospitalized patients with SARS-CoV-2 infection: a multicentre cohort study (PREDI-CO study)
Objectives: We aimed to develop and validate a risk score to predict severe respiratory failure (SRF) among patients hospitalized with coronavirus disease-2019 (COVID-19). Methods: We performed a multicentre cohort study among hospitalized (>24 hours) patients diagnosed with COVID-19 from 22 February to 3 April 2020, at 11 Italian hospitals. Patients were divided into derivation and validation cohorts according to random sorting of hospitals. SRF was assessed from admission to hospital discharge and was defined as: SpO2 <93% with 100% FiO2, respiratory rate >30 breaths/min or respiratory distress. Multivariable logistic regression models were built to identify predictors of SRF, \u3b2-coefficients were used to develop a risk score. Trial Registration NCT04316949. Results: We analysed 1113 patients (644 derivation, 469 validation cohort). Mean (\ub1SD) age was 65.7 (\ub115) years, 704 (63.3%) were male. SRF occurred in 189/644 (29%) and 187/469 (40%) patients in the derivation and validation cohorts, respectively. At multivariate analysis, risk factors for SRF in the derivation cohort assessed at hospitalization were age 6570 years (OR 2.74; 95% CI 1.66\u20134.50), obesity (OR 4.62; 95% CI 2.78\u20137.70), body temperature 6538\ub0C (OR 1.73; 95% CI 1.30\u20132.29), respiratory rate 6522 breaths/min (OR 3.75; 95% CI 2.01\u20137.01), lymphocytes 64900 cells/mm3 (OR 2.69; 95% CI 1.60\u20134.51), creatinine 651 mg/dL (OR 2.38; 95% CI 1.59\u20133.56), C-reactive protein 6510 mg/dL (OR 5.91; 95% CI 4.88\u20137.17) and lactate dehydrogenase 65350 IU/L (OR 2.39; 95% CI 1.11\u20135.11). Assigning points to each variable, an individual risk score (PREDI-CO score) was obtained. Area under the receiver-operator curve was 0.89 (0.86\u20130.92). At a score of >3, sensitivity, specificity, and positive and negative predictive values were 71.6% (65%\u201379%), 89.1% (86%\u201392%), 74% (67%\u201380%) and 89% (85%\u201391%), respectively. PREDI-CO score showed similar prognostic ability in the validation cohort: area under the receiver-operator curve 0.85 (0.81\u20130.88). At a score of >3, sensitivity, specificity, and positive and negative predictive values were 80% (73%\u201385%), 76% (70%\u201381%), 69% (60%\u201374%) and 85% (80%\u201389%), respectively. Conclusion: PREDI-CO score can be useful to allocate resources and prioritize treatments during the COVID-19 pandemic
Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
International audienceWe report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power
Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
International audienceWe report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power
Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
International audienceWe report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power
Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
International audienceWe report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power