경희의료원 마취통증의학과 R3 전주연 British journal of anaesthesia. 2005;94:778-83

1. Comparison of propofol/remifentanil and sevoflurane/remifentanil for maintenance of anaesthesia for elective intracranial surgery 경희의료원 마취통증의학과 R3 전주연 British journal of anaesthesia. 2005;94:778-83

2. Background • IV and inhalation agents are in general use for maintenance of anesthesia during neurosurgery • Comparisons btw iv and inhalation have been inconclusive • Remifentanyl – rapid onset, promptly elimination, low instance of pain • No published reports, compare sevo/remi and propofol/remi in neurosurgery

3. Methods • Fifty pts. Undergoing elective craniotomy • Double-blind design- rejected (easy detection of sevoflurane by smell) • Arterial pressure- direct measurement from the radial a. and stored at 1-min intervals • Hypertension and hypotension by inspection of the stored electronic record

4. Method-Anaesthesia • Remifentanyl • Bolus- 1μg/kg • Infusion- 0.5 μg/kg – 0.25 μg/kg after craniotomy • Group P (propofol anesthesia) • TCI (Target controlled infusion) of propofol • Initial plasma conc. – (1 μg/ml) was increased progressively until satisfactory anesthesia • Maintained by the TCI with a minimum target conc. Of 2 μg/ml

5. Method-Anaesthesia • Group S (sevoflurane anesthesia) • Bolus injection propofol- 0.5mg/kg c supplementary doses of 10mg every 10s until loss of consciousness • Maintain • Initial ET conc. 2% minimum conc. 1% • Tracheal intubation • Atracurium as bolus and followed by an infusion until dural closure • Normocapnia • Fresh gas flow – 0.5L/min O2, 1.0L/min Air

6. Method-Anaesthesia • Remifentanyl infusion stopped after skin closure • Sevoflurane and propofol were continued until head bandaging was completed • Mannitol • 1g/kg – given bt induction of anesth. And craniotomy • Surgeon – state of brain(tight, adequate, soft) • Dose of mannitol was recorded

7. Method-Anaesthesia • Hypertensive episode • MAP > 100mmHg for more than 1min • Treated c remi 1 μg/kg and infusion rate increased by 0.125 μg/kg/min • Labetolol or hydralazine was given • Hypotensive episode • MAP < 60mmHg for more than 1min • Reducing the propofol target or sevoflurane conc. • Vasopressor was administered if necessary

8. Method-Anaesthesia • Time to adequate respiration, extubation, eye opening and obey commands • Analgesia was provided by bolus injections of morphine 2mg • Nausea and vomiting and the discharge time were recorded.

9. Method-Statisticalanalysis • Statview and excel v. 7 • Continuous variables • Mann-Whitney U-test • Categorical valuables • chi-squared test • P < 0.05 – statistically significant • Drug acquisition costs • post-hoc

10. Results • Group P (24pt.) • Propofol infusion rate • 5.45 mg/kg/h • Group S (26pt.) • 1.06mg/kg propofol for induction • ET conc. Of sevo. • 1.13 % • Remifentanil infusion rate • Similar in the two group • Aaesthesia time • Longer in group P – difference was not significant

11. Results • Arterial pressure before, during, and after surgery was similar. • Hypertensive episodes • 7 and 8 pt. in group P and S • No significant difference (P=0.374, chi square) • Labetolol 14 and 19pt in group P and S • Hydralazine 2 and 5 pt in group P and S • Hypotensive episodes • 15 and 23 pt in group P and S • No significant difference • Ephedrine 63 and 88% pt in group P and S • Total dose of ephedrine 4.8 and 9.8 mg in group P and S

12. Results • Time to spontaneous respiration • Shorter in group P and S(P=0.02) • Time to eye opening, extubation, obeying commands • were not statistically significant • Relationship btw. Recovery time and hypotensice episodes • Were not significantly correlated • Requirement for morphine, dosage of morphine, incidences of N/V and recovery room stay were similar

13. Results • Total hypnotic , analgesic drug and vasoactive drug acquisition costs • Group P > Group S (19.31 > 15.52/h) • Significantly high ( P= 0.016)

14. Discussion • Sevoflurane and propofol in combination with remifentanil • Satisfactory agents for maintenance of anaesthesia in neurosurgical patients. • Increased number of hypotensive episodes in group S • Group S simply more deeply anaesthetized • CP50 of propofol – 5.45μg/ml • IC50 of sevo – 1.14% • Average target propofol conc. – 3.67 μg/ml • Average ET sevo conc. – 1.13%

15. Discussion • Small and clinically unimportant differences in recovery bt Group P and Group S • Many reports to compare recovery characteristics • Sevoflurane gave faster, similar, or slower recovery than propofol anesthesia • Ex) Yli-Hankala – no difference of recovery • Evaluation whether hypotensive episodes were associated with delayed recovery – No correlation

16. Discussion • PONV • Many studies – sevoflurane caused PONV more frequently than propofol anesthesia. • PONV – 30% of patients receiving sevoflurane • PONV occurred in only 15% of patients with no difference between propofol and sevoflurane • Small difference in drug acquisition costs • Difference are very small in relation to the total cost of a neurosurgical procedure

17. Discussion • Realistic doses of propofol and sevoflurane • Recognize the strong synergism bt. these agents and remifentanil. • Common clinical doses of remifentanil • Substantial sparing of sevoflurane and propofol • Previous study – propofol infusion rate 100μg/kg/min – too high • We have carefully evaluated sevo, and propofol as maintenance agents with remifentanil for elective intracranial surgery. • Both agents were satisfactory