Analgesia ladder:

The WHO analgesic ladder is a useful tool when deciding what pain medications are necessary

Step 1: when pain first occurs a non-opioid should be provided e.g. paracetamol, NSAIDs, Cox2 inhibitors.

Step 2 If pain persists or increases, a weak opioid as well as a non-opioid should be used e.g. codeine, tramadol.

Step 3 If pain is still present or increasing a strong opioid should be used with or without a non-opioid e.g. morphine, oxycodone, fentanyl.

Patient controlled analgesia: A specific type of IV delivery system using an infusion pump. Opioid is delivered when a patient decides it is needed and pushes a button connected to the pump.