Objective: To compare two anesthetic techniques, total intravenous anaesthesia performed with midazolam-alfentanil and classic inhalation anaesthesia.
Design: Prospective comparison of two anaesthetic techniques in patients (ASA I and II), of the same age range, randomly divided in two groups, undergoing operations of the same type by the same surgical team.
Setting: Department of Surgery and Anaesthesia of a teaching hospital in Athens-Greece.
Patients: Group A (20) received 1 ml droperidol as premedication, thiopental 5 mg/kg body weight, fentanyl 2 mg/kg and atracurium 0.5 mg/kg for induction to anaesthesia; anaesthesia was maintained with fentanyl 5 mg/kg, 0.5-1% halothane and a mixture of nitrous oxide and oxygen, and muscle relaxation with atracurium 6-7 mg/kg. Group B (20) was given midazolam 0.06 mg/kg as premedication. For induction of anaesthesia this group was given midazolam 0.25 mg/kg and alfentanyl 30 mg/kg; atracurium 0.5 mg/kg was also given for muscle relaxation. Anaesthesia was maintained by midazolam 4 mg/kg/min, alfentanil 1.5 mg/kg/min and oxygen enriched air and muscle relaxation with atracurium 6-7 mg/kg/min. The depth of anaesthesia was assessed by the standard clinical signs (arterial pressure, heart rate) and by several biochemical tests (blood glucose and cortisol levels).
Analysis: Student's "t" test and chi 2 test.
Results: No statistical difference was noted between the two groups pre-operatively regarding arterial pressure, heart rate, blood glucose and cortisol levels. During operation the heart rate and mean arterial pressure were within normal range. Group B patients had a slightly lower (p < 0.05) minimal arterial pressure. A considerable increase in blood glucose was noted during the operation period in both groups; no difference was observed between the two groups of patients. Cortisol levels increased from the early stages of the operation in both groups and to some extent in the postoperation period. This last increase was significantly higher in Group A.
Conclusion: Total intravenous anaesthesia (TIVA) seems simple, safe and feasible in hospitals of this country.