Ventilator Hyperinflation and Manual Rib Cage Compression

Comparison Between Ventilator Hyperinflation and Manual Rib Cage Compression: Randomized Crossover Trial

This is a randomized crossover trial to evaluate the effects of thoracic compression applied alone or in association with hyperinflation maneuver with the ventilator. In addition, the mobilized volume and peak expiratory flow resulting from both maneuvers will be evaluated.

Ventilator hyperinflation is widely used in hypersecretive patients. It consists of increasing alveolar ventilation by facilitating the coughing mechanism so that the secretions of the peripheral airways are mobilized into the central airways so that they can be removed by tracheal aspiration or cough. Thoracic compression consists of manually compressing the rib cage during expiration, in order to increase expiratory flow, mobilize and remove pulmonary secretions. A randomized crossover clinical trial was performed with 30 patients submitted to isolated compression or associated with ventilator hyperinflation, with a 6 hour interval. Patients were evaluated through compliance and resistance of the respiratory system.

Expiratory rib cage compression was performed in 6 sets of 6 cycles, with 1 cycle interval. Ventilatory mode and parameters were maintained.

Expiratory rib cage compression was performed in 6 sets of 6 cycles, with 1 cycle interval. Ventilator hyperinflation was performed by increasing the inspiratory pressure to every 5 cmH2O until the total pressure reached 40 cmH2O, remaining the same.

Compression was performed in 6 sets of 6 cycles, with 1 cycle interval. Ventilatory mode and parameters were maintained.

Mechanical ventilator hyperinflation was performed by increasing the inspiratory pressure to every 5 cmH2O until the total pressure reached 40 cmH2O, remaining the same. In Expiratory Rib Cage Compression associated with ventilator hyperinflation, thoracic compression maneuver was performed at the end of inspiration, at the exact moment of cycling.

Compliance was assessed through the occlusion maneuver at the end of inspiration, considering tidal volume, plateau pressure and PEEP. Three measurements were taken at each moment, the mean being used.

Baseline (before), immediately after ventilator hyperinflation or rib cage compression and five minutes after aspiration

The total resistance of the respiratory system was evaluated through the occlusion maneuver at the end of the inspiration, considering the resistive pressure, measured by the difference between the maximum plateau pressure. Three measurements were taken at each moment, the mean being used.

Baseline (before), immediately after ventilator hyperinflation or rib cage compression and five minutes after aspiration

The airway resistance was assessed by means of the occlusion maneuver at the end of the inspiration, considering the rapid fall of the pressure immediately after the occlusion, measured by the difference between the maximum pressure and P1. Three measurements were taken at each moment, the mean being used.

Baseline (before), immediately after ventilator hyperinflation or rib cage compression and five minutes after aspiration

The peak expiratory flow was evaluated through passive expiration, being considered the greatest value of the flow in the expiratory phase.

Baseline (before), immediately after ventilator hyperinflation or rib cage compression and five minutes after aspiration

Inclusion Criteria: patients under mechanical ventilation diagnosis of pulmonary infection hypersecretive Exclusion Criteria: haemodynamic instability (heart rate > 130 bpm and mean arterial pressure < 60 mmHg) acute bronchospasm acute respiratory distress syndrome untreated pneumothorax