Chapter 7: Moving and positioning
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Positioning a patient to maximize the drainage of secretions
Anatomy and physiology
The trachea branches into two bronchi, one to each lung (Figure 7.17). Each main bronchus then divides into lobar and then segmental bronchi (upper, middle and lower on the right; upper and lower on the left), each one branching into two or more segmental bronchi with smaller and smaller diameters, until they reach the bronchioles and finally the alveoli (Tortora and Derrickson [122]).
Figure 7.17 The bronchial tree. Source: Reproduced from Peate et al. ([100]) with permission of John Wiley & Sons, Ltd.
The walls of the airways are lined with epithelium, which contains cilia. The cilia constantly beat in a co‐ordinated movement, propelling the mucus layer towards the pharynx. The mucus layer traps any dust particles or foreign objects, which can then be transported along the ‘mucociliary escalator’, which is an important part of the lungs’ defence mechanism (Figure 7.18). An increased volume of mucus is produced in response to airway irritation and in some disease states (Tortora and Derrickson [122]).
Figure 7.18 The mucociliary escalator. Source: Reproduced from DeTurk and Cahalin ([30]) with permission of The McGraw Companies.
A reduced ability to effectively remove this mucus can lead to an increased bacterial load and therefore may compromise respiratory functioning by causing airway obstruction. This can lead to segmental atelectasis or lobar collapse, and long term it can lead to chronic inflammation and airway destruction (Lumb and Nunn [63]).
Pre‐procedural considerations
Pharmacological support
Administering nebulizers
Non‐pharmacological support
Humidification
Drainage of secretions will be optimized if the patient and therefore the mucus layer and cilia are well hydrated. This can be ensured via adequate humidification.
