The pharmacokinetic behaviour of opioids administered during cardiac surgery.

Cardiac surgery with hypothermic cardiopulmonary bypass (CPB) is among the most commonly performed operations in Canada today. The potential effects of hypothermia and CPB on the disposition of certain opioids are reviewed. Reasons for prolongation of the elimination half-time of the opioids used during cardiac surgery are explored. The roles that age, hypothermia, protein binding and drug sequestration may play in changing opioid pharmacokinetic behaviour are examined and suggestions for future research are made.