Acute Hemodynamic Responses to Ventilator Hyperinflation Technique in Critical Traumatic Patients With Pulmonary Complications

The World Health Organization reported that Thailand ranked third for number of road fatalities at 38.1 per 100,000 inhabitants in 2010. Most of these cases were admitted to the intensive care unit (ICU) for respiratory interventions such as intubation and mechanical ventilation that can lead to a common problem of pulmonary complications such as pneumonia and atelectasis.

Evidence supports the effectiveness of chest physical therapy technique (CPT) to improve alveolar collapse and remove pulmonary secretion. A previous study has shown that the positive airway pressure technique reduced work of breathing (WOB) and re-inflated lung atelectasis. The use of positive pressure devices has been part of physiotherapy intervention since intermittent positive pressure breathing was introduced in clinical practice. In intensive care settings, the use of positive pressure by physiotherapists includes manual hyperinflation (bagging or bag squeezing), which has been shown to increase oxygenation and mobilize excessive bronchial secretions, and to re-inflate collapsed areas.

Manual hyperinflation technique (MHI) is provided for use in patients with lung atelectasis. Several studies demonstrated the short-term effects of increased oxygenation and pulmonary compliance, improved lung collapse, and removed pulmonary secretions. To apply MHI technique, patients were disconnected from the ventilator which lead to the adverse effect of losing positive end expiratory pressure (PEEP) corresponding to loss of functional residual capacity, decreased oxygenation, and shear stress of distal lung units.

An alternative method of performing pulmonary hyperinflation uses the mechanical ventilator. Although there is evidence that positive pressure interventions such as continuous positive airway pressure (CPAP) and intermittent positive pressure breathing IPPB) can improve lung expansion and mobilize secretions in the airway, there are few studies examining ventilator-induced hyperinflation as a physiotherapy intervention in intensive care.

A previous study showed that the ventilator hyperinflation technique (VHI) was as effective as MHI to improve pulmonary complications such as secretion retention and lung atelectasis. Especially, VHI technique using applied by the mechanical ventilator, patient was not disconnected from the ventilator and therefore did not result in loss of PEEP and its adverse effect.