aspects of postoperative pain control

Last reviewed 01/2018

After surgery, abdominal muscle spasm can elevate the diaphragm resulting in tachycardia. Subsequently, there is microatelectasis. Additionally, there is an inability to cough, resulting in retained secretions, segmental collapse, chest infection and pyrexia. Ideal analgesia aims to minimize these complications.

Postoperative pain control takes several forms:

• psychological reassurance; presurgery anxiety directly correlates with the level of postoperative pain
• intermittent intramuscular opiate analgesia; its weakness is that between 4 hourly injections, pain is still occasionally reported
• continuous opiate infusion; effective, but may precipitate pulmonary dysfunction by respiratory depression
• patient-operated analgesic systems; small preset doses are administered on demand
• use of selective opioids; certain drugs produce less respiratory depression than morphine, and may be given orally
• extradural blockade; patients receiving epidural analgesia, e.g. bupivacaine 0.5%, intraoperatively and for 12 hours postoperatively had less pain than those receiving intermittent IM morphine
• intercostal nerve block; this does not relieve visceral pain, and there is a risk of pneumothorax
• perfusion of surgical wounds with long-acting agents such as bupivacaine may reduce narcotic requirements
• transcutaneous electrical stimulation (TENS); TENS may reduce narcotic requirements, but not respiratory complications

Ref: McLatchie, G.R.,(1992). Oxford Handbook of clinical Surgery. OUP.