Have there been changes in the application of mechanical ventilation in relation to scientific evidence? A multicenter observational study in Mexico.

Abstract Objective The main study objectives were to describe the practice of mechanical ventilation over an 18-year period in Mexico, and estimate changes in mortality among critical patients subjected to invasive mechanical ventilation (IMV). Design A retrospective subanalysis of a prospective observational study conducted in 1998, 2004, 2010 and 2016 was carried out. Setting Intensive Care Units (ICUs) in Mexico. Participants Adult patients consecutively enrolled in the ICU during one month and who underwent IMV for more than 12 h or noninvasive mechanical ventilation for more than one hour. Follow-up was performed up to a maximum of 28 days after inclusion. Interventions None. Principal variables of interest Age, sex, severity upon admission as estimated by SAPS II, parameters of daily arterial blood gases, treatment and complication variables, date and status at discharge from the ICU and from hospital. Results A total of 959 patients were included in 81 ICUs. Tidal volume (vt) decreased significantly both in patients with acute respiratory distress syndrome (ARDS) criteria (estimated 8.5 mL/kg b.w. in 1998 to 6 mL/kg in 2016; P  Conclusions The clinical practice of IMV in Mexican ICUs has been modified over a period of 18 years. The most significant change is the ventilatory strategy based on low vt. These changes have not been associated with significant changes in mortality.