Abstract
Objective To compare the effect of different dosage of ketarnine on bispectral index (BIS) in patients sedated with dexmedetomidine (DEX). Methods Eighty ASA class Ⅰ or Ⅱ patients scheduled for gynecologic operation under epidural anesthesia were evenly randomized to ketaraine groups Kl, K2, K3 and normal saline group (group N). When the expected anesthetic plane was obtained. Dex was then given to patients in all four groups with a loading dose of 0. 5 μg · kg-1 , and then continuing medication with Dex at the rate of 0. 5- 1. 0 μg /(kg · h). When BIS declined to 60 and stabilized for 10 min, intravenous ketamine 0. 2, 0. 4 and 0. 6 mg/kg was offered to patients in groups Kl, K2 and K3, respectively. To those in group N, isovolume of normal saline was given. Heart rate (HR), mean arterial blood pressure ( MABP), BIS and OAA/S were recorded before and 0 min, 3 min, 6 min, 9 min, 12 min and 15 min after the infusion of ketamine. Results The differences of HR, MAP, and BIS between before administration of ketamine and in group Kl were not significant (P>0. 05) , but OAA/S was lower in group Kl (F=3.66,q=4. 472 -5.367,P<0.05). In group K2, the HR and MAP did not change obviously after ketamine was given (p> 0. 05), BIS increased after three minutes of ketamine infusion (F=2. 60,q=4. 642,P<0.05), and returned to its before ketamine-medication level at six minutes, and OAA/S decreased significantly (F=18. 65,9=11. 424,P<0, 05). In group K3, MAP did not show much changes before and after giving ketamine (P>0. 05), .and HR increased at different time points (F=7. 46,q=5. 530 - 7. 604 "P<0. 05) . BIS increased significantly at 3~ 9 minutes after ketamine infusion, OAA/S lowered significantly (F= 71. 36. Q=22. 350,P<0. 05). Compared with group N, the differences of OAA/S, HR, MAP and BIS in group Kl were not significant (P>0.05); the BIS in group K2 elevated dramatically at three minutes after injection of ketamine (F= 7. 72 ,q-4. 788 ,P<0.05). OAA/S lowered significantly at 0-15 minutes after injection of ketamine (F=18.64-44.90,q=6, 828-12. 213,P<0.05), but the differences of HR and MAP were not significant (P>0. 05) j BIS increased significantly in group K3 at 3 - 9 minutes after ketamine injection (F=3. 34-7. 72,p=3. 787-5. 267, P<0. 05). OAA/S lowered significantly at 0-15 minutes (9 = 9. 454-12. 932.P<0. 05) , but HR and MAP did not change obviously (P>0. 05). Conclusion A single small dose of ketamine used during the stage of sedation with dexmedetomidine. BIS does not reflect the patient's real depth of sedation, but will notably deepen the patient'5 depth of anesthesia.关键词
氯胺酮/右美托咪啶/麻醉,硬膜外/双频谱指数Key words
ketamines dexmedetomidine / anesthesia/ epidural/ bispectral index分类
临床医学
