Gravity Assisted Drainage (GAD)
Gravity assisted drainage positions (also known as GAD or postural drainage) can be used to assist the clearance of excess bronchial secretions from the lungs (Eaton et al 2007).
Fig. 1 Anatomical angles of the lung segments
The technique involves placing the patient in a position which allows gravity to assist in draining mucus from the periphery of the lungs to the central upper airway as shown in Fig 1&2 and Table 1.
Figure 2. Gravity Assisted Drainage positions
Depending on the anatomical angle of the lobes or segments of the lungs to be drained (Fig. 1), the patient may be placed in sitting, prone, supine, side lying or in a head down tilt of between 15 and 30 degrees.
The resulting positive effect on airway clearance and secretion expectoration is due to both gravity assisting drainage and improved ventilation (Lannefors & Wollmer 1992, Zack et al 1974).
Table 1. Gravity Assisted Drainage positions