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

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Structural RFV: Recovery Form and Defaultable Debt Analysis

Receiving the same fractional recovery of par at default for bonds of the same issuer and seniority, regardless of remaining maturity, has been labelled in the academic literature as a Recovery of Face Value at Default (RFV). Such a recovery form results from language found in typical bond indentures and is supported by empirical evidence from defaulted bond values. We incorporate RFV into an exogenous boundary structural credit risk model and compare its effect to more typical recovery forms found in such models. We find that the chosen recovery form can significantly affect valuation and the sensitivities produced by these models, thus having important implications for empirical studies attempting to validate structural credit risk models. We show that some features of existing structural models are a result of the recovery form assumed in the model and do not necessarily hold under an RFV recovery form. Some of our results complement those found in the literature which examines the endogeneity of the default boundary. We find that some features that may have been solely attributed to modelling the boundary as an optimal decision by the fir

Coordinator Rotation Via Domatic Partition In Self-Organizing Sensor Networks

We investigate the problem of energy conservation in ClusterHead rotation in wireless sensor networks. Nodes are battery powered without being replenished, thus maximizing lifetime of network by minimizing energy consumption poses challenge in design of protocols. We argue, though clustering addresses lifetime and scalability goals, it results to an expensive load-balancing scheme based on ClusterHead rotation(i.e. reclustering).The load balancing technique of existing clustering schemes uses global rotation of ClusterHead roles in order to prevent any single node from complete energy exhaustion. Theoretically, the problem of rotating the responsibility of being a ClusterHead has been abstracted as domatic partitioning problem for maximum cluster-lifetime problem. Instead, this work presents an analysis of its design and implementation aspects. We propose a domatic partitioning based scheme for ClusterHead rotation in clustering protocol. Our self-organizing protocol achieves energy-conservation in achieving local load balancing of nodes. The simulation results demonstrate that our approach outperforms re-clustering in terms of energy consumption, and lifetime parameters. © 2007 IEEE

Voiding pressures in boys: Pdetmax versus pdetQmax – Does it make a difference?

Introduction: Invasive urodynamics (UDS) is a standard investigation in children. Studies measuring voiding pressures in children use varied nomenclatures and quote a wide range of voiding pressures. Thus, voiding pressures in children are not considered reliable and they do not find any place in the pediatric diagnostic armamentarium. On the contrary, adult studies have well-defined nomograms and standard values which make voiding studies indispensable in the diagnosis of voiding dysfunctions in adults. The difference primarily lies in the uniformity of parameters assessed in adults and the contrasting heterogeneity in the pediatric literature. Objective: The objective of this study was to study the voiding parameters observed during UDS in boys. Study Design: We retrospectively reviewed the pressure flow data obtained during conventional invasive UDS in 106 neurologically normal boys (6 months–16 years) who had different indications for urodynamics. The values of Pdetmax and PdetQmax were analyzed and compared with the existing data of pressure flow studies in children. Results: Pdetmax decreased with age whereas PdetQmax was independent of age. The difference between the values of Pdetmax and PdetQmax was more in the younger kids. The wide range of voiding detrusor pressure (Pdet) in the existing pediatric literature is similar to the values of Pdetmax observed in our study, whereas the value of PdetQmax is much lower. Discussion: The values of Pdetmax observed in this study are similar to the values of “maximum Pdet during voiding” documented in previous studies and are determined by detrusor contractility and functional/dynamic contraction of outflow during voiding. PdetQmax has been documented in very few pediatric studies and is significantly less than Pdetmax. Further prospective studies are needed to corroborate UDS findings with radiologic/cystoscopic findings to create nomograms of voiding parameters in children. Conclusion: Existing literature on pediatric voiding studies mentions voiding pressures during variable phases of void (usually Pdetmax) and the values have been very heterogeneous, making voiding pressure-flow studies unreliable in children. PdetQmax values are much lower than values quoted as “standard” pressures and are age independent. The use of PdetQmax instead of PdetMax may make voiding pressures in children more reproducible and informative