Pain research update from a genetic point of view.

Molecular biology investigates the genetic causes of many diseases. Currently, molecular biology in pain research lags behind the investigations of the molecular basis of mental disorders. A significant challenge in pain genetic research is the fact that pain involves emotional factors.

The association of monoamine oxidase B functional polymorphism with postoperative pain intensity.

Objectives: The monoamine oxidase B (MAO-B) is an enzyme involved in metabolism of dopamine, benzylamine, phenylethylamine, tyramine and tryptamine. The A/G polymorphism in intron 13 of the MAO-B gene has been previously found to be associated with variability of the MAO-B enzyme activity. The aim of the present association study has been to examine the relationship between the A/G polymorphism in intron 13 and postoperative pain intensity.

A high initial VAS score and sedation after iv morphine titration are associated with the need for rescue analgesia.

Purpose: Administration of sc morphine has been recommended two hours after the end of iv morphine titration in the postanesthesia care unit (PACU), but in some cases patients complain of pain earlier than this. We assessed pain after the end of iv morphine titration and studied the characteristics of patients who needed rescue sc morphine.

Methods: Postoperative pain was assessed using the visual analogue scale (VAS; 0 to 100) and the threshold required to administer morphine in the PACU was a score of 30.