Final answer:
PCA can lead to nausea, vomiting, respiratory depression, hypotension, urinary retention, and additional effects such as weakness, fatigue, and muscular problems, with severe cases possibly leading to adrenal crisis and circulatory collapse.
Step-by-step explanation:
Some adverse reactions and complications associated with Patient-Controlled Analgesia (PCA) include nausea and vomiting, which may persist for 24-48 hours and lead to possible dehydration and changes in blood pressure and heart rate. Another significant concern is respiratory depression, an especially dangerous complication because it can lead to insufficient oxygenation of the body. Patients may also experience hypotension (low blood pressure), which could result in dizziness and increase the risk of falls and other injuries. Urinary retention is another potential complication where the patient is unable to empty the bladder fully, leading to discomfort and potential infection. Additional responses include weakness, fatigue, agitation, anxiety, sleep problems, abnormal heart rhythms, and muscular problems. In severe cases, complications like adrenal crisis can occur, which is characterized by severe pain in the abdomen, lower back, and legs; circulatory system collapse; and kidney failure.