Rationale and study design for an Individualized PeriopeRative Open lung VEntilatory approach in Emergency Abdominal Laparotomy/scopy: study protocol for a prospective international randomized controlled trial.

BACKGROUND: Postoperative pulmonary complications (PPC) are the most frequent postoperative complications, with an estimated prevalence in elective surgery ranging from 20% in observational cohort studies to 40% in randomized clinical trials. However, the prevalence of PPCs in patients undergoing emergency abdominal surgery is not well defined. Lung-protective ventilation aims to minimize ventilator-induced lung injury and reduce PPCs. The open lung approach (OLA), which combines recruitment manoeuvres (RM) and positive end-expiratory pressure (PEEP) titration, aims to minimize areas of atelectasis and the development of PPCs; however, there is no conclusive evidence in the literature that OLA can prevent PPCs. The purpose of this study is to compare an individualized perioperative OLA with conventional standardized lung-protective ventilation in patients undergoing emergency abdominal surgery with clinical signs of intraoperative lung collapse. METHODS: Randomized international clinical trial to compare an individualized perioperative OLA (RM plus individualized PEEP and individualized postoperative respiratory support) with conventional lung-protective ventilation (standard PEEP of 5 cmH2O and conventional postoperative oxygen therapy) in patients undergoing emergency abdominal surgery with clinical signs of lung collapse. Patients will be randomised to open-label parallel groups. The primary outcome is any severe PPC during the first 7 postoperative days, including: acute respiratory failure, pneumothorax, weaning failure, acute respiratory distress syndrome, and pulmonary infection. The estimated sample size is 732 patients (366 per group). The final sample size will be readjusted during the interim analysis. DISCUSSION: The Individualized Perioperative Open-lung Ventilatory Strategy in emergency abdominal laparotomy (iPROVE-EAL) is the first multicentre, randomized, controlled trial to investigate whether an individualized perioperative approach prevents PPCs in patients undergoing emergency surgery.

Use of thoracic fluid content for prediction of fluid balance and postoperative pulmonary complications after major abdominal surgery: an observational study.

BACKGROUND AND OBJECTIVES: The harmful effects of excess fluids frequently manifest in the lungs. Thoracic fluid content (TFC) is a variable provided by the STARLINGTM bioreactance monitor, which represents the total volume of fluid in the chest. The objective is to analyse the association between the variation in TFC values (TFCd0%) at 24 h postoperatively, postoperative fluid balance, and postoperative pulmonary complications. MATERIAL AND METHODS: Prospective and analytical observational study. Patients scheduled for major abdominal surgery at a tertiary teaching hospital were included. They were monitored during the intervention and the first 24 postoperative hours with the monitor. STARLINGTM, measuring TFC and its variation in different stages of the perioperative period. Serial lung ultrasounds were performed and postoperative pulmonary complications were recorded. Logistic regression was performed to predict the occurrence of atelectasis and pulmonary congestion. The Pearson correlation coefficient was calculated to verify the association between TFC and fluid balance. RESULTS: 50 patients were analyzed. TFCd0% measured on the morning of the first postoperative day increased by a median of 27.1% [IQR: 20.3-37.5] and was correlated at r = 0.44 with the postoperative balance of 677 ml [IQR: 125.5-1,412]. Increased TFC was related to a higher risk of atelectasis (OR = 1.24) and pulmonary congestion (OR = 1.3). CONCLUSIONS: TFCd0% measured 24 h after surgery presents a moderate correlation with postoperative fluid balance. Its increase is a risk factor for the appearance of postoperative pulmonary complications.

Uso del contenido de fluido torácico para la predicción del balance hídrico y las complicaciones pulmonares postoperatorias tras cirugía abdominal mayor / Use of thoracic fluid content for prediction of fluid balance and postoperative pulmonary complications after major abdominal surgery: An observational study

Antecedentes y objetivos: Los efectos nocivos del exceso de líquidos se manifiestan frecuentemente en los pulmones. El contenido de fluido torácico (thoracic fluid content [TFC]) es una variable que proporciona el monitor por biorreactancia STARLING™, que representa el volumen total de líquido en el tórax. El objetivo es analizar la asociación entre la variación de los valores del TFC (TFCd0%) a las 24horas postoperatorias, el balance hídrico postoperatorio y las complicaciones pulmonares postoperatorias. Material y métodos: Estudio observacional prospectivo y analítico. Se incluyeron pacientes programados para cirugía abdominal mayor en un hospital universitario de tercer nivel. Fueron monitorizados durante la intervención y las 24 primeras horas postoperatorias con el monitor STARLING™, midiendo el TFC y su variación en distintas etapas del perioperatorio. Se realizaron ecografías pulmonares seriadas y se recogieron las complicaciones pulmonares postoperatorias. Se realizó una regresión logística para predecir la aparición de atelectasias y congestión pulmonar. Se calculó el coeficiente de correlación de Pearson para comprobar la asociación entre TFC y balance hídrico. Resultados: Se analizaron 50 pacientes. El TFCd0% medido en la mañana del primer día postoperatorio aumentó una mediana del 27,1% [IQR: 20,3-37,5] y se correlacionó con una r=0,44 con el balance postoperatorio de 677ml [IQR: 125,5-1.412]. El aumento del TFC se relacionó con un mayor riesgo de sufrir atelectasias (OR=1,24) y congestión pulmonar (OR=1,3). Conclusiones: El TFCd0% medido a las 24horas de la cirugía presenta una correlación moderada con el balance hídrico postoperatorio. Su incremento es un factor de riesgo para la aparición de complicaciones pulmonares postoperatorias.(AU)

Background and objectives: The harmful effects of excess fluids frequently manifest in the lungs. Thoracic fluid content (TFC) is a variable provided by the STARLINGTM bioreactance monitor, which represents the total volume of fluid in the chest. The objective is to analyze the association between the variation in TFC values (TFCd0%) at 24 hours postoperatively, postoperative fluid balance, and postoperative pulmonary complications. Material and methods: Prospective and analytical observational study. Patients scheduled for major abdominal surgery at a tertiary teaching hospital were included. They were monitored during the intervention and the first 24 postoperative hours with the monitor. STARLINGTM, measuring TFC and its variation in different stages of the perioperative period. Serial lung ultrasounds were performed and postoperative pulmonary complications were recorded. Logistic regression was performed to predict the occurrence of atelectasis and pulmonary congestion. The Pearson correlation coefficient was calculated to verify the association between TFC and water balance. Results: 50 patients were analyzed. TFCd0% measured on the morning of the first postoperative day increased by a median of 27.1% [IQR: 20.3-37.5] and was correlated at r=0.44 with the postoperative balance of 677 ml [IQR: 125.5-1,412]. Increased TFC was related to a higher risk of atelectasis (OR=1.24) and pulmonary congestion (OR=1.3). Conclusions: TFCd0% measured 24 hours after surgery presents a moderate correlation with postoperative fluid balance. Its increase is a risk factor for the appearance of postoperative pulmonary complications.(AU)