Understanding the Pleurevac.

The infant nonmetered Pleurevac was studied under laboratory conditions. Evacuation of a spirometer was measured at various negative pressures through the infant thoracostomy tubes routinely used in the clinical setting. In addition, a tension pneumothorax model was designed, and factors affecting its evacuation rate were studied. In accordance with Poiseuille's law, the evacuation rate was proportional to the negative pressure applied to the thoracostomy tube, and the radius of the tube. The airflow rate (bubble rate) through the Pleurevac was found to be of minor importance in affecting evacuation.