Patient controlled analgesia

Abstract

An overview of its use in pain management Analgesia is the patient’s ability not to detect pain while conscious. Inadequate pain control is a common complaint among inpatients and such pain increases morbidity and mortality. In particular, pain can inhibit patients’ ability to breathe deeply, cough, and move. This increases the risk of chest infection, deep vein thrombosis, and pulmonary embolism. Pain control, therefore, is of paramount importance. Successful analgesia should treat pain effectively and minimise side effects without the risk of overdose. Patient controlled analgesia can be used in many clinical situations, including after operations, oncology, sickle cell crises,1 and burns management. It is essentially maintenance once the patient’s pain is initially controlled. It allows patients to administer the appropriate doses of analgesia when required, which has been shown to reduce associated anxiety.2 Analgesia should be administered in an escalating fashion appropriate to the patient’s intensity of pain. Using this stepwise approach the administration of unnecessary analgesia can be avoided, and the patients’ pain can be controlled before considering patient controlled analgesia (fig 1⇓). Fig 1 Analgesic ladder, a stepwise approach to initial pain control Simple analgesics, such as paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs), are often initially prescribed and can be of benefit in many conditions. Paracetamol is a commonly used first line drug for treating pain and also pyrexia. It may also have a weak anti-inflammatory action.3 This is thought to occur by inhibition of the cyclo-oxygenase-3 enzyme. NSAIDs, such as ibuprofen and diclofenac, work by inhibiting cyclo-oxygenase enzymes in inflammatory cells. This causes a reduction in the metabolism of arachadonic acid and a resultant decrease in prostaglandin synthesis. This leads to antipyretic, anti-inflammatory, and analgesic effects. Should paracetamol and NSAIDs prove inadequate, a weak opioid, such as codeine, can be added …