<p> Aim and intended learning outcomes </p> <p>The aim of this continuing education article is to develop the reader’s understanding of the basic principles of patient-controlled analgesia (PCA), its clinical uses and the factors that influence its effectiveness. At the end of the article, you should be able to: ■<p>Explain briefly how a PCA system works</p>■<p>Describe the advantages and disadvantages of PCA</p>■<p>Understand the importance of monitoring a patient using PCA</p>■<p>Explain the importance of patient control.</p></p>