What percentage sensitivity can be achieved by having the patient sit upright for 10 minutes in cases of perforated viscus?

Having the patient sit upright for 10 minutes can significantly enhance the sensitivity of detecting free air in cases of perforated viscus. The rationale for this practice involves the dynamics of air movement within the abdominal cavity. When a perforation occurs, air can escape from the gastrointestinal tract into the peritoneal cavity. By positioning the patient upright, the free air rises to the highest point in the peritoneal cavity, typically underneath the diaphragm, making it more visible on imaging studies like X-rays or CT scans.

The sensitivity range of 30-80% indicates that while the technique improves detection, it is not foolproof. Factors such as the amount of free air present, the patient's body position before assessing, and the quality of imaging can all influence the final outcome. This percentage reflects that when patients are upright, there's a notable but not complete enhancement in the ability to identify free air associated with perforated organs.