Assessment of clinical and laboratory factors predictive of difficulty of weaning in adult patients admitted to an Intensive Care Unit

• Grant number: 16/12286-4
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2016
• End date: March 31, 2018
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Lucieni de Oliveira Conterno
• Grantee: Lucieni de Oliveira Conterno
• Host Institution: Faculdade de Medicina de Marília (FAMEMA). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). Marília , SP, Brazil
• Associated researchers: Maria Aparecida Vitagliano Martins ; Silene El-Fakhouri

Abstract

The removal of patients from mechanical ventilation (MV) continues to challenge medical professional, however, there is no definitive and safe predictor of the outcome of weaning. The daily awakening, followed by spontaneous breathing test (TER), reduces the duration of MV and its complications. During the TRE, with the withdrawal of sedation and ventilation under positive pressure, occur cardiorespiratory stimulus, increased respiratory rate, changes in intrathoracic pressures, increased venous return, increased transmural pressure of the left ventricle and increased afterload. Such stimuli induce the secretion of atrial natriuretic peptide within minutes in response to volume overload and pressure, heart. Thus, the dosage levels of natriuretic peptides can be useful to identify the point at which the patient is ready for weaning. Other factors such as age and adverse events such as pneumonias associated with mechanical ventilation can also contribute to the difficulty of weaning. General Objective: To determine the predictive factors of weaning in adult patients admitted to a general intensive unit, medical and surgical treatment. Specific Objectives: To determine the prevalence of successful weaning in patients on mechanical ventilation for more than 24 hours; determine the impact of age in the evolution of weaning; determine which clinical and epidemiological and laboratory variables are associated with weaning; specifically assess whether the natriuretic peptide levels are associated with difficult weaning; compare the outcomes of patients with major and minor age 60 who have had success and failure in ventilatory weaning in relation respiratory adverse events, ventilation time, hospital time and evolution presented. Design: prospective cohort study including adult patients on MV for more than 24 hours, admitted to the Intensive Care Unit B (UTI_B) of Marilia University Hospital.Participants: Adult patients, over 18 years, admitted to the UTI- B in the period between April 2016 and March 2017 with VM, or evolve, after hospitalization, requiring intubation and mechanical ventilation for more than 24 hours . Data collection will be conducted through standardized form. Patients will be evaluated initially by APACHE II, SAPS II and SOFA and monitored for adverse events (barotraum, tracheobronchitis and pneumonia associated with ventilator, other infections, venous thromboembolism, gastrointestinal bleeding), and subjected to doses atrial natriuretic peptide immediately before the start of the TRE, and immediately before extubation. Patients will be followed up until discharge from the ICU or death. Patients who are readmitted to the ICU after seven days of discharge, requiring new endotracheal intubation and VM will be considered new, and those cases, readmitted within 48 hours after discharge, will be considered as failure. Statistical analysis will be performed in descriptive analysis (mean, median and proportions). Continuous variables were compared by Student's t-test and categorical variables were compared by chi-square test or Fisher's exact test. The value of p <0.05 is considered statistically significant. To define the ability of plasma BNP in differentiating patients who have had success in weaning from mechanical ventilation, those who failed will be calculated the sensitivity, specificity, positive predictive value and negative predictive value. The patients with success in the weaning will be compared with those who failed, in relation to clinical and laboratory variables. If the number of cases allow, logistic regression analysis will be performed to verify the independent variables associated with the success / failure of weaning. (AU)