[Perioperative management with short-acting intravenous anesthetics]

Total intravenous anaesthesia (TIVA) with short-acting drugs is a standard procedure for day case surgery and is increasingly used for neurosurgical, cardiac surgical and paediatric surgical operations. The combination of propofol with alfentanil or remifentanil is frequently applied due to its favourable pharmacological properties. Propofol is characterized by a large volume of distribution at steady state and a relatively long elimination half time (t1/2 beta). Because of a high metabolic clearance, the clinical effects of propofol decline rapidly even after prolonged intravenous drug infusion. In patients with increased age, obesity or liver or renal failure, decreased doses of propofol for induction of anaesthesia are recommended. The short-acting opioids alfentanil and remifentanil provide small volumes of distribution at steady state, a short blood-brain equilibration time and decreased t1/2 beta. Remifentanil has unique pharmacological properties due to an ester binding and its elimination via extrahepatic hydrolysis by non-specific blood and tissue esterases. The context sensitive half time of remifentanil is significantly shorter than that of other opioids. Its analgetic potency is equal to fentanyl and 20 to 30 times higher than alfentanil. The advantages of total intravenous anaesthesia include fewer haemodynamic side-effects, a decreased incidence of postoperative nausea and vomiting and less neurohumoral stress response to surgery. Adequate pain therapy is mandatory after total intravenous anaesthesia with short-acting drugs. Continuous infusion of remifentanil for postoperative analgesia or supplementation of regional anaesthesia requires careful monitoring of vital functions. The economic aspects of TIVA remain to be determined.