Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Identification of light particles by means of pulse shape analysis with silicon detector at low energy

Particle separation of 1,2,3H at energy of 3 MeV has been achieved by digital pule shapeanalysis (DPSA) for particles fully stopped in a View the MathML sourcesilicondetector. Light charged particles were produced in a nuclear reaction induced by a 34 MeV beam of 7Li impinging on a 12C target. Proton-deuterium identification has also been observed at 2 MeV using mono-energetic beams. A 20 keV resolution neutron transmutation doped (NTD) silicondetector was employed in a low-field injection setup. The method uses the parameters obtained both from the charge and current pulses generated by a high bandwidth charge sensitive preamplifier. The simplicity of the electronic chain plus the experimental conditions allowed the team to work with very low noise achieving signal-to-noise ratio (SNR) at values greater than 10

Dependency on the silicon detector working bias for proton-deuteron particle identification at low energies

Proton-deuteron identification at energies between 2.5 MeV and 6 MeV has been studied as a function of the detector working bias. Digital pulse shape analysis (DPSA) has been used to perform the separation from the two mono-energetic beams. The technique makes use of the current signal delivered by a View the MathML source500μm neutron transmutation doped (NTD) silicon detector, which was setup for low-field injection. It is shown that identification of the H isotopes is better when the detector working bias is close to the depletion voltage rather than over-depletion. The presence of high frequency noise diminished the possibility of identification, however, the use of a simple triangular smoothing algorithm counteracted this

Breakup and neutron-transfer effects on 6He+206Pb elastic scattering below the Coulomb barrier

The elastic scattering and inclusive alpha-particle yield for the He-6 + Pb-206 system at an incident energy of 18 MeV, just below the nominal Coulomb barrier, have been measured. The alpha-particle yield at forward angles is also reported. The data are analyzed by means of continuum-discretized coupled-channels, distorted wave Born approximation, and coupled reaction channels calculations. Couplings to the one-neutron- and two-neutron-transfer reactions are found to be able to account for most of the absorption in the entrance channel

Interstrip effects influence on the particle identification of highly segmented silicon strip detector in a nuclear reaction scenario

Identification of the interstrip effects using digital pulse shape analysis is for the first time reported. This study is performed on a highly segmented double-sided silicon detector used in a nuclear reaction in which a large range of particles at different energies are produced. The output current pulse of the preamplifier is employed as observable. The interstrip effects diminish the capability of particle identification at energies below 5 MeV, especially on the injection side of the detector

Elastic scattering measurements for the system 7Be + 28Si at 17.2 MeV

Elastic scattering of 7Be+28Si was studied at several near barrier energies for probing the energy dependence of the optical potential. Our analysis at 17.2 MeV will be presented in this article and discussed, in terms of Continuum Coupled Channel Calculations (CDCC). This research is part of a long term plan concerning the energy dependence of the optical potential for weakly bound projectiles, at near barrier energies and for probing the potential threshold anomaly. The experiment took place at the EXOTIC facility - Laboratori Nationali di Legnaro (LNL), and refers to an angular distribution measurement, using the detector array EXPADES (Exotic Particle Detection System). Results at 9 MeV (Rutherford region) were also analyzed and were used for estimating the solid angle. Our analysis for other energies is under process

Important influence of single neutron stripping coupling on near-barrier ⁸Li + ⁹⁰Zr quasi-elastic scattering

Quasi-elastic scattering data were obtained for the radioactive nucleus 8Li on a 90Zr target at the near-barrier energy of 18.5MeV over the angular range $\theta_{lab}=15^{\circ}$ to 80\ub0. They were analyzed within the coupled channels and coupled reaction channels frameworks pointing to a strong coupling effect for single neutron stripping, in contrast to 6, 7Li + 90Zr elastic scattering at similar energies, a non-trivial result linked to detailed differences in the structure of these Li isotopes

Direct and compound-nucleus reaction mechanisms in the Be 7 + Ni 58 system at near-barrier energies

The energy and angular distributions of He3 and He4 ions produced in the Be7+Ni58 reaction at a bombarding energy of 22 MeV have been measured for the first time. The yield of the heavier helium isotope was four to five times more abundant than that of its lighter counterpart, ruling out the possibility that in this energy range the Be7 reaction dynamics is dominated by the exclusive breakup process Be7\u21923He+He4 (S\u3b1=1.586 MeV). Extensive kinematic and theoretical calculations suggest that the He3 ions mostly originate from the He4-stripping process and the He4 production is mainly triggered by the fusion-evaporation channel. The role played by the breakup, He3-stripping, 1n-stripping, and 1n-pickup processes is also discussed

Mapping the amplitude and position response of double sided silicon strip detectors with monochromatic single protons

International audienceWe are currently developing a novel detection system featuring high angular and energy resolution and able to reconstruct the particles momentum at high precision for different physical cases in multi-fragmentation nuclear physics experiments, based on Double Sided Silicon Strip Detectors as ΔE stages aimed at performing also pulse shape analysis for fragments stopping therein. We carried out a detailed qualification of the performance of the strip detectors. In order to provide the detector response matrix we used a pulsed monoenergetic proton beam. The paper reviews the pulsed proton beam facility of the LaBeC of INFN - Sezione di Firenze and present the results of the characterization of the DSSSD prototypes with the pulsed proton beam. In particular we will discuss the amplitude and time response mapping and we will present the analysis of the dependence of the signal shape as a function of the position of interaction

Near barrier scattering of 8He on 208Pb

The exotic nucleus He-8 is investigated by means of the measurement of the angular distributions of the elastic channel and the He-6 and He-4 fragment yields produced in the collision with a Pb-208 target at two energies around the Coulomb barrier, 16 and 22 MeV. The experiment was performed at the GANIL-SPIRAL facility, with the aim of extracting information about the structure of He-8 and the relevant reaction mechanisms. In this contribution, details of the experimental setup and preliminary data on elastic cross sections are reported