Effects of Ventilator Hyperinflation Versus Vibrocompression on Lung Compliance in Mechanically Ventilated Patients

Lower respiratory infections remained the world's most deadly communicable disease, ranked as the 4th leading cause of death.

The aim of mechanical ventilation is to reduce the ventilatory work and maintain gas exchange, but it also has deleterious effects on mucociliary transport and coughing ability. These effects provoke the stasis of secretions in the airways and bronchial obstruction, with hypoventilation, atelectasis, and consequent hypoxemia. This set of factors also favors microorganism multiplication and, thus, an increased incidence of ventilator-associated pneumonia (VAP), impaired gas exchange, pulmonary infection and fibrosis, and progressive reduction of lung compliance. To reverse or reduce these deleterious effects, bronchial hygiene techniques are used by physical therapists in several ICUs around the world. Among these techniques, tracheal aspiration, vibrocompression (VB), and hyperinflation with mechanical ventilation are commonly employed.

Lung compliance is inversely proportional to elastance. This elastic resistance is due to the elastic property of lung tissue or parenchyma and the surface elastic force. Any changes occurring to these forces could lead to changes in compliance. Compliance determines 65% of the work of breathing. If the lung has low compliance, it requires more work from breathing muscles to inflate the lungs. In specific pathologies, continuous monitoring of the lung compliance curve is useful to understand the condition's progression and to decide on therapeutic settings needed for ventilator management So, the current study will help to determine the effects of ventilator hyperinflation and vibrocompression on lung compliance and sputum production in mechanically ventilated patients.