This study of the safety of patients undergoing mechanical ventilation was undertaken to ensure correct ventilation and to find quality-control elements for patients and nursing staff. Differences in mode programming and ventilation parameters and their registry at the change of nursing shifts, and correct programming of the sensitivity and minimum minute volume alarms and maximum airway pressure alarms were examined. In a two-month period, 8 cross-sectional studies were made of G1 prevalence in each of three nursing shifts. The status of the alarms and sensitivity were recorded when incorrect, as well as whether the ventilation mode and parameters coincided with the change of nursing shift. An analysis was made of: FiO2, PEEP, respiratory rate, minute volume, tidal volume, support pressure level, and control pressure level depending on the ventilation mode. Corrective measures were applied for a month. The effectiveness of these measures was evaluated by making 8 new G2 cross-sectional studies of the same type. Two hundred forty-eight G1 and 250 G2 recordings were made. The G2 studies revealed a generalized reduction in errors for all parameters. We concluded that the corrective measures were effective so these indicators were included in the monitoring of risk areas in the unit quality control program.