They are not precise and are very uncomfortable. Light percussion is just as informative. Any pain elicited in the obese patient is significant. The panniculus acts as a damper to pressure. Note pulse rate and rhythm, blood pressure, temperature, respiratory rate, and the characteristics of the respiratory cycle.
Hypotension can result from gastrointestinal bleeding, dehydration, vagal stimulation, etc.
Note any abdominal asymmetry, distension, bulges, scars, or splinting of the chest or abdomen during respiration. Short, grunting respirations can indicate basilar pneumonias or upper-abdominal inflammatory conditions. Use either the bell or diaphragm and minimal pressure. Hyperperistalsis with rushes, cramps, and diarrhea suggests gastroenteritis. Hypoperistalsis or a silent abdomen favors serious surgical conditions.