Management of pain

World Health Organisation Analgesic Ladder

• Initially peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are given.
• If pain control is not achieved, the second part of the ladder is to introduce weak opioid drugs such as codeine or dextropropoxyphene together with appropriate agents to control and minimise side effects.
• The final rung of the ladder is to introduce strong opioid drugs such as morphine. Analgesia from peripherally acting drugs may be additive to that from centrally-acting opioids and thus, the two are given together.

The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder

• For management of acute pain
• Initially, the pain can be expected to be severe and may need controlling with strong analgesics in combination with local anaesthetic blocks and peripherally acting drugs.
• The second rung on the postoperative pain ladder is the restoration of the use of the oral route to deliver analgesia. Strong opioids may no longer be required and adequate analgesia can be obtained by using combinations of peripherally acting agents and weak opioids.
• The final step is when the pain can be controlled by peripherally acting agents alone.

Local anaesthetics

• Infiltration of a wound with a long-acting local anaesthetic such as Bupivacaine
• Analgesia for several hours
• Further pain relief can be obtained with repeat injections or by infusions via a thin catheter
• Blockade of plexuses or peripheral nerves will provide selective analgesia in those parts of the body supplied by the plexus or nerves
• Can either be used to provide anaesthesia for the surgery or specifically for postoperative pain relief
• Especially useful where a sympathetic block is needed to improve postoperative blood supply or where central blockade such as spinal or epidural blockade is contraindicated.

Spinal anaesthesia

Provides excellent analgesia for surgery in the lower half of the body and pain relief can last many hours after completion of the operation if long-acting drugs containing vasoconstrictors are used.

Side effects of spinal anaesthesia include: hypotension, sensory and motor block, nausea and urinary retention.