A data-driven model to describe and forecast the dynamics of COVID-19 transmission

Purpose: This paper proposes a methodology and a computational tool to study the COVID-19 pandemic throughout the world and to perform a trend analysis to assess its local dynamics. Methods: Mathematical functions are employed to describe the number of cases and demises in each region and to predict their final numbers, as well as the dates of maximum daily occurrences and the local stabilization date. The model parameters are calibrated using a computational methodology for numerical optimization. Trend analyses are run, allowing to assess the effects of public policies. Easy to interpret metrics over the quality of the fitted curves are provided. Country-wise data from the European Centre for Disease Prevention and Control (ECDC) concerning the daily number of cases and demises around the world are used, as well as detailed data from Johns Hopkins University and from the Brasil.io project describing individually the occurrences in United States counties and in Brazilian states and cities, respectively. U. S. and Brazil were chosen for a more detailed analysis because they are the current focus of the pandemic. Results: Illustrative results for different countries, U. S. counties and Brazilian states and cities are presented and discussed. Conclusion: The main contributions of this work lie in (i) a straightforward model of the curves to represent the data, which allows automation of the process without requiring interventions from experts; (ii) an innovative approach for trend analysis, whose results provide important information to support authorities in their decision-making process; and (iii) the developed computational tool, which is freely available and allows the user to quickly update the COVID-19 analyses and forecasts for any country, United States county or Brazilian state or city present in the periodic reports from the authorities.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)2020/14357-

Effects of elevated artificial pneumoperitoneum pressure on invasive blood pressure and levels of blood gases

Background and objective: to evaluate the clinical, hemodynamic, gas analysis and metabolic repercussions of high transient pressures of pneumoperitoneum for a short period of time to ensure greater security for introduction of the first trocar. Methods: sixty-seven patients undergoing laparoscopic procedures were studied and randomly distributed in P12 group: n = 30 (intraperitoneal pressure [IPP] 12 mmHg) and P20 group: n = 37 (IPP of 20 mmHg). Mean arterial pressure (MAP) was evaluated by catheterization of the radial artery; and through gas analysis, pH, partial pressure of oxygen (PaO2), partial pressure of CO2 (PaCO2), bicarbonate (HCO3) and alkalinity (BE) were evaluated. These parameters were measured in both groups at time zero before pneumoperitoneum (TP0); at time 1 (TP1) when IPP reaches 12 mmHg in both groups; at time 2 (TP2) after five min with IPP = 12 mmHg in P12 and after 5 min with IPP = 20 mmHg at P20; and at time 3 (TP3) after 10 min with IPP = 12 mmHg in P12 and with return of IPP from 20 to 12 mmHg, starting 10 min after TP1 in P20. Different values from those considered normal for all parameters assessed, or the appearance of atypical organic phenomena, were considered as clinical changes. Results: there were statistically significant differences in P20 group in MAP, pH, HCO3 and BE, but within normal limits. No clinical and pathological changes were observed. Conclusions: high and transient intra-abdominal pressure causes changes in MAP, pH, HCO3 and BE, but without any clinical impact on the patient. Keywords: Artificial pneumoperitoneum, Laparoscopy, Surgical instruments, Monitoring, Intraoperativ

Efectos de la presión elevada del neumoperitoneo artificial sobre la presión arterial invasiva y los niveles de los gases sanguíneos

Background and objective:to evaluate the clinical, hemodynamic, gas analysis and metabolic repercussions of high transient pressures of pneumoperitoneum for a short period of time to ensure greater security for introduction of the first trocar.Methods:sixty-seven patients undergoing laparoscopic procedures were studied and randomly distributed in P12 group: n = 30 (intraperitoneal pressure [IPP] 12 mmHg) and P20 group: n = 37 (IPP of 20 mmHg). Mean arterial pressure (MAP) was evaluated by catheterization of the radial artery; and through gas analysis, pH, partial pressure of oxygen (PaO2), partial pressure of CO2 (PaCO2), bicarbonate (HCO3) and alkalinity (BE) were evaluated. These parameters were measured in both groups at time zero before pneumoperitoneum (TP0); at time 1 (TP1) when IPP reaches 12mmHg in both groups; at time 2 (TP2) after five min with IPP = 12mmHg in P12 and after 5 min with IPP = 20mmHg at P20; and at time 3 (TP3) after 10 min with IPP = 12mmHg in P12 and with return of IPP from 20 to 12mmHg, starting 10min after TP1 in P20. Different values from those considered normal for all parameters assessed, or the appearance of atypical organic phenomena, were considered as clinical changes.Results:there were statistically significant differences in P20 group in MAP, pH, HCO3 and BE, but within normal limits. No clinical and pathological changes were observed.Conclusions:high and transient intra-abdominal pressure causes changes in MAP, pH, HCO3 and BE, but without any clinical impact on the patient.Justificación y objetivo:evaluar las repercusiones clínicas, hemodinámicas, gasométricas y metabólicas de las altas presiones transitorias del neumoperitoneo durante un corto período de tiempo para garantizar una mayor seguridad en la introducción del primer trocar.Métodos:fueron estudiados 67 pacientes sometidos a procedimientos videolaparoscópicos y distribuidos aleatoriamente en grupo P12: n = 30 (presión intraperitoneal [PIP] de 12 mmHg), y grupo P20: n = 37 (PIP de 20 mmHg). Se evaluó la presión arterial media por cateterismo de la arteria radial; y mediante gasometría, el pH, la presión parcial de oxígeno arterial, la presión parcial de CO2 arterial, el bicarbonato y la reserva alcalina. Esos parámetros fueron evaluados en ambos grupos en el tiempo cero, antes del neumoperitoneo (TP0); en el tiempo uno (TP1), cuando la PIP alcanza 12 mmHg en ambos grupos; en el tiempo 2 (TP2), después de 5 min con PIP de 12 mmHg en P12 y después de 5 min con PIP de 20 mmHg en P20; y en el tiempo 3 (TP3), después de 10 min con PIP de 12 mmHg en P12 y con PIP de retorno desde 20 mmHg a 12 mmHg, contados 10 min después de TP1 en P20. Los valores diferentes de los considerados normales para los parámetros medidos o el surgimiento de fenómenos orgánicos atípicos fueron considerados alteraciones clínicas.Resultados:hubo diferencias estadísticas significativas en el grupo P20 en la presión arterial media, en el pH, en el bicarbonato y en la reserva alcalina, pero dentro de los límites de la normalidad. No se evidenciaron alteraciones clínicas ni patológicas.Conclusiones:la presión intraabdominal alta y transitoria causa alteraciones de la presión arterial media, del pH, del bicarbonato y de la reserva alcalina sin repercusiones clínicas para el paciente.Justificativa e objetivo:avaliar as repercussões clínicas, hemodinâmicas, gasométricas e metabólicas das altas pressões transitórias do pneumoperitônio por curto período de tempo que garantem maior segurança para a introdução do primeiro trocarte.Métodos:foram estudados 67 pacientes submetidos a procedimentos videolaparoscópicos e aleatoriamente distribuídos em grupo P12: n = 30 (pressão intraperitoneal [PIP] de 12 mmHg) e grupo P20: n = 37 (PIP de 20 mmHg). Foram avaliados a pressão arterial média (PAM), por cateterismo da artéria radial; e, mediante gasometria, o pH, a pressão parcial de oxigênio arterial (PaO2), a pressão parcial de CO2 arterial (PaCO2), o bicarbonato (HCO3) e a reserva alcalina (BE). Esses parâmetros foram avaliados em ambos os grupos no tempo zero, antes do pneumoperitônio (TP0); no tempo um (TP1), quando a PIP atinge 12 mmHg em ambos os grupos; no tempo dois (TP2), após cinco minutos com PIP de 12 mmHg em P12 e após cinco minutos com PIP de 20 mmHg em P20; e no tempo três (TP3), após 10 minutos com PIP de 12 mmHg em P12 e com PIP retornada de 20 mmHg para 12 mmHg, contados 10 minutos após TP1 em P20. Os valores diferentes dos considerados normais para os parâmetros aquilatados ou o surgimento de fenômenos orgânicos atípicos foram considerados alteracões clínicas.Resultados:ocorreram diferenças estatísticas significantes no grupo P20 na PAM, no pH, no HCO3 e na BE, mas dentro dos limites da normalidade. Não foram evidenciadas alterações clínicas e patológicas.Conclusões:pressão intra-abdominal alta e transitória causa alterações da PAM, do pH, do HCO3 e da BE sem que haja repercussão clínica no paciente.Universidade Federal de São Paulo (UNIFESP)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaHospital Municipal José de Carvalho FlorenceUNIFESP, EPMSciEL