The evaluation of the expansion or descend of the diaphragm on full inspiration.
Reduced diaphragmatic expansion may have local or distal aetiologies. Local aetiologies include muscle spasm of the diaphragm (sub-phrenic absence, gastric irritation, cardiac and pericardial associations, perforating ulcers, hernias and other causes. Distal causes include lesions of the phrenic nerve which originates from C3-C5.
If the patient is acute then taking a deep breath may be painful or will not attempt it. Also the patient may be having tachypnoea but again shallow breaths.
Those with poor lung expansion or phrenic lesions the excursion of the diaphragm will be reduced even with full inspiration. Measurement of diaphragmatic descend is reasonably easy to assess using percussion.
1. As a patient to fully inhale and then fully exhale and whilst they hold their breath percuss the posterior thoracic wall. Start from around rib 7 and percuss inferiorly until the resonant lung sounds are replaced by the dull sounds of the diaphragm and the abdominal contents below that. Mark the point of sound change. Then repeat this procedure this time the patients hold their breath in in full inhalation. Then mark the new position between resonant and dull sounds. The normal degree of excursion is about 3-5 cm. When percussing you need to be fast considering the patient is holding their breath.
(Full details and demonstration of procedures are provided with the DVD/videos and associated study material)