Lung hyperinflation by mechanical ventilation versus isolated tracheal aspiration in the bronchial hygiene of patients undergoing mechanical ventilation

Abstract

ObjectiveTo determine the efficacy of lung hyperinflation maneuvers via a mechanical ventilator compared to isolated tracheal aspiration for removing secretions, normalizing hemodynamics and improving lung mechanics in patients on mechanical ventilation.MethodsThis was a randomized crossover clinical trial including patients admitted to the intensive care unit and on mechanical ventilation for more than 48 hours. Patients were randomized to receive either isolated tracheal aspiration (Control Group) or lung hyperinflation by mechanical ventilator (MVH Group). Hemodynamic and mechanical respiratory parameters were measured along with the amount of aspirated secretions.ResultsA total of 50 patients were included. The mean age of the patients was 44.7 ± 21.6 years, and 31 were male. Compared to the Control Group, the MVH Group showed greater aspirated secretion amount (3.9g versus 6.4g, p = 0.0001), variation in mean dynamic compliance (-1.3 ± 2.3 versus -2.9 ± 2.3; p = 0.008), and expired tidal volume (-0.7 ± 0.0 versus -54.1 ± 38.8, p = 0.0001) as well as a significant decrease in peak inspiratory pressure (0.2 ± 0.1 versus 2.5 ± 0.1; p = 0.001).ConclusionIn the studied sample, the MVH technique led to a greater amount of aspirated secretions, significant increases in dynamic compliance and expired tidal volume and a significant reduction in peak inspiratory pressure.

Airway Clearance Techniques for Mechanically Ventilated Patients: Insights for Optimization

“…Since then, many studies on ventilator hyperinflation have been carried out with general samples of critical care patients. [30][31][32][33][34] These studies confirmed the similarity between ventilator hyperinflation and manual hyperinflation in clearing secretions, improving respiratory mechanics, and gas exchange. 30,32,33 Nevertheless, there is a lack of studies addressing the effects of ventilator hyperinflation or manual hyperinflation on long-term clinically relevant outcomes, such as length of stay, duration of mechanical ventilation, weaning, and incidence of ventilator-associated pneumonia.…”

“…Moreover, different from manual hyperinflation, ventilator hyperinflation makes it possible to monitor and set the parameters of interest for the technique's application. 32,33,35 Studies on ventilator hyperinflation have used different criteria to determine the inspiratory volume: 50% above the current tidal volume, 34 130% of the set tidal volume, 32 15 mL/kg, 33 and volume corresponding to a peak inspiratory pressure of 40 cm H 2 O. 30,31,35 Regardless of the criteria chosen, the peak inspiratory pressure was limited to 40 cm H 2 O.…”

“…30,31,35 Regardless of the criteria chosen, the peak inspiratory pressure was limited to 40 cm H 2 O. The main modes used for ventilator hyperinflation were volume control CMV 30,34 and pressure support ventilation. 31 Regarding the inspiratory time or flow settings during ventilator hyperinflation, the following were used: inspiratory time of 3-5 s, 33 inspiratory flow of 20 L/min plus an inspiratory pause of 2 s, 30 or no modification at all.…”

Comparison of bronchial hygiene techniques in mechanically ventilated patients: a randomized clinical trial

“…Previous studies have shown that lung hyperinflation techniques can improve pulmonary oxygenation and compliance and reverse lung collapse and atelectasis. ( 2,7-10,15 ) This is due to the ability of hyperinflation to increase TV, leading to the expansion of both ventilated and collapsed alveoli; this phenomenon is explained by the pulmonary interdependence mechanism, which facilitates the transport of secretions from the peripheral airways to the central airways. ( 15,16 )…”

Recursos fisioterapêuticos utilizados em unidades de terapia intensiva para avaliação e tratamento das disfunções respiratórias de pacientes com covid-19

“…Além da influência da pressão positiva aplicada às vias aéreas, a ventilação dos alvéolos será dependente da ação da gravidade, fazendo com que regiões do pulmão não dependentes (i.e., sem contato com a cama) gerem pressões pleurais mais negativas, convergindo para expansão passiva. Nesse contexto, regiões pulmonares colapsadas devem ser posicionadas de forma não dependente da gravidade, pois serão passivamente expandidas 33,34 . A postura assumida pelos pacientes é fundamental nesse contexto.…”