[Postoperative patient controlled analgesia]

Patient controlled analgesia (PCA) helps patients to achieve a better comfort both at rest and when dynamic pain is concerned. This aim can be reached by closing the feedback loop in a shorter time. The purpose is to keep drug concentration in the narrow therapeutic range of MEAC (minimal effective analgesic concentration). Two methods of administration can be used: demand bolus; continuous infusion rate plus demand bolus. Continuous infusion method together with opioids administration increases lethal complications 0.28 to 1.08% (p<0.05), unless patient controlled epidural analgesia (PCEA) is performed. Therefore, this method can be used only in ICU environment. An effective and safe dose delivering and a correct infusion timing is now possible due to recent improvement in technology. The success in PCA depends more by parameters chosen, patient and healthcare personnel compliance, monitoring of S(p)O(2), respiratory rate, pain VAS and Sedation Score than by the drug administered. There is recent evidence that PCA improves patient's comfort, but does not reduce the amount of personnel work, postoperative morbidity, analgesic consumption and costs.