Glucose response during craniotomy: propofol-remifentanil versus isoflurane-remifentanil

BACKGROUND

Major surgery is associated with a stress response. The aim of this study was to compare the effects of isoflurane or propofol, both supplemented with remifentanil, on the glucose, cortisol and insulin-based stress responses prospectively.

METHODS

Forty patients undergoing craniotomy randomly received either 1% isoflurane (Group I, N.=20) or propofol 6 mg kg h(-1) (Group P, N.=20) during remifentanil-based (0.125 μg kg min(-1)) anesthesia. Blood glucose was recorded preoperatively, after induction, intubation and pin placement, before and after skin incision, craniotomy, dura incision, 15th, 30th, 60th, 90th, 120th, 150th, 180th min post-dura incision, following dura and skin closure, extubation and at the 1st and 24th postoperative hours. Insulin and cortisol were measured preoperatively, after intubation, dura incision, at the 60th min, extubation and at the 1st and 24th hour postoperatively. The glucose/insulin ratio and glycemic stress index were calculated after all the measurements were obtained.

RESULTS

Patient characteristics were comparable in both groups. Blood glucose significantly decreased after induction in comparison to the baseline value in both groups. Blood glucose was significantly higher in Group I than Group P before skin incision, after craniotomy and dura incision and at all measurement time points after the 60th minute following dura incision. There was a significant alteration with time in insulin values in both groups and the insulin values at the 60th min were significantly lower in Group I than in Group P. There was not any difference in the inter-group analysis of cortisol; however, there was a significant change over time in the insulin values in both groups. There was no difference in the intra-group glucose/insulin ratio, however, there was a significant difference between groups at the 60th min and at extubation. The Glycemic Stress Index was comparable between groups (Group I vs. Group P: 2.48±1.15 vs. 2.15±0.86, P=0.465).

CONCLUSION

Isoflurane and propofol, both combined with remifentanil, provided clinically comparable cortisol and insulin responses to surgery in craniotomy operations, whereas propofol attenuated the increase in plasma blood glucose.

Comparison of midazolam sedation with or without fentanyl in cataract surgery

We compared the effect of midazolam sedation with or without fentanyl on the hemodynamic parameters, sedation, and pain and satisfaction profile in cataract surgery. Two hundred and ten patients were randomly allocated to receive either midazolam 1 mg i.v. (Group M, n = 101) alone or with fentanyl 25 microg (Group MF, n = 100) before retrobulbar injection. Hemodynamic parameters, observer's assessment of alertness/sedation (OAA/S) scores, pain during block and surgery, satisfaction of patient and surgeons were assessed. Heart rate and diastolic arterial pressure decreased after retrobulbar injection in comparison to baseline whereas systolic arterial pressure values increased in both groups. The majority of patients in both groups experienced mild pain during retrobulbar injection but no pain during surgery. There was a significant decrease in OAA/S scores in both groups (p = 0.001) and this decline was more significant in Group MF (p = 0.038). We suggest that midazolam alone may produce optimal block conditions for the patient and it is satisfactory during the procedure while the addition of fentanyl has not improved the effect on the examined parameters.