[Weaning from mechanical ventilation in patients with exacerbations of chronic respiratory insufficiency--personal...

Nineteen patients with exacerbation of chronic respiratory insufficiency treated with mechanical ventilation were included in the study. The mean weaning time from the respirator was 15.9 days (+/- 12.1), ranging from 2 to 49 days. Success was met in 9 patients using inspiratory pressure support (IPS), in 2 synchronized intermittent mandatory ventilation (SIMV), in 8 the simplest model (stepwise prolongation of spontaneous ventilation during continuous mechanical ventilation--CMV/SV). All options were used in the same patients throughout the weaning procedure. The use of IPS led to a successful weaning in those patients in whom other options (CMV/SV, SIMV) were not fortunate. The application of IPS was begun at 40 cm H2O, gradually decreasing the support pressure. The duration of spontaneous breathing in all weaning options was not only depended on gasometric values, continuous SaO2 monitoring, but mainly on the patients' subjective sense of fatigue. The impression of exhaustion preceded the changes of gasometric parameters and fall of SaO2. The basis of effective weaning is proper selection of respirator parameters, providing almost identical gasometric values if individual patient's to those prior exacerbation of chronic respiratory insufficiency. The duration of weaning negatively correlated (0.25) with FEV1 values.