Cardiorespiratory Phase Synchronization Analysis in Patients undergoing Mechanical Ventilation during the Extubation Process*

Mechanical ventilation remains the main medical treatment for acute respiratory failure and is one of the defining interventions of intensive care medicine as a specialty. Some patients continue to fail in the extubation process against all odds. This study investigates the contribution of cardiorespiratory phase synchronization (CRPS) analysis as a function of a threshold value and window length, to classify patients in the mechanical ventilation weaning process. Patients were classified according to the outcome of the trial, successful (S), failed (F), and reintubated (R). Parameters related to synchronization periods between heartbeats and respiratory cycles, based on thresholds and window length, were analyzed. The most pronounced differences were obtained with a threshold of 0.2. Group F showed the maximum value for most CRPS parameters, whereas group S showed the minimum value. The average values of all the maximum synchronization functions above the threshold were significantly higher in group R compared to group S. These results could help us to understand why there are patients who need to be reintubated when the clinical process considers extubation to be possible.