Postoperative pain and its management.

In recent years tremendous progress has been made in our understanding of peripheral, spinal cord and brain mechanisms involved in acute pain and in the neurophysiologic description of nociceptive pathways, receptors and mediators. Great strides have been made in our knowledge of pharmacokinetics and pharmacodynamics of drugs used to treat pain. However, in spite of unprecedented interest in pain and its management, most patients undergoing surgery still receive treatments that have changed little in the past decades. Untreated severe postoperative pain has many deleterious effects on respiration, circulation, autonomic activity, renal function and gastrointestinal activity. The technique of pain control does have a significant influence on postoperative complications particularly in high risk patients undergoing major surgery. Today we have a variety of effective modalities to control postoperative pain. These include different opioid administration techniques such as spinal opioids (epidural, intrathecal), patient controlled analgesia (i.v., subcutaneous, epidural), i.v. infusions, sublingual, oral transmucosal ("lollipop"), rectal, nasal, intra articular. Non-opioid analgesics such as non-steroidal anti-inflammatory drugs and alpha-adrenergic agents (systemic, epidural, intrathecal) are available. Various combinations of the above are also possible. However, it is increasingly recognised that the solution to the problem of inadequate pain relief on surgical wards lies not so much in the development of new drugs and new techniques but in the development of a formal organisation for better use of existing drugs and techniques. A simple, low-cost organisation model for acute pain services (APS) is described.