[Balanced anesthesia with continuous ketamine reduces adverse effects of remifentanil].
BACKGROUND
We evaluated the use of continuous infusion of ketamine to reduce intraoperative remifentanil side effects, such as bradycardia and hypotension, and to improve postoperative analgesia from balanced anesthesia with remifentanil.


METHODS
Forty patients undergoing spine surgery under remifentanil-based anesthesia were randomly assigned to intraoperative ketamine group and saline (control) group. Balanced anesthesia was maintained with infusion of propofol (2-4 mg x kg(-1) x hr(-1)), remifentanil (6-8 microg x kg(-1) hr(-1)) and vecuronium (60-80 microg x kg(-1) x hr(-1)) with nitrous oxide (60%) and with or without ketamine (300-400 microg x kg(-1) x hr(-)). All patients were given scheduled NSAIDs by their own doctor at the end of surgery. Intraoperative bradycardia (HR <50) and hypotension (SBP <80), and postoperative additional NSAIDs request were recorded.


RESULTS
Adverse events, such as bradycardia and hypotension, were less frequent in the ketamine group (P < 0.05). Less additional NSAIDs was required in the ketamine than in the control group (P < 0.05). Emergence time from anesthesia was within 5 min in both groups.


CONCLUSIONS
Remifentanil-based anesthesia with continuous ketamine decreases intraoperative side effects and postoperative NSAIDs request. Thus, intraoperative continuous ketamine may be a useful adjuvant to remifentanil.
Onaka
Masahiko
M
Department of Anesthesia, Shunjukai Shiroyama Hospital, Habikino 583-0872.
Yamamoto
Hiromitsu
H
D000759:Adjuvants, Anesthesia; D000328:Adult; D000768:Anesthesia, General; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001919:Bradycardia / Q000139:chemically induced* / Q000517:prevention & control*; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000517:prevention & control*; D007262:Infusions, Intravenous; D007431:Intraoperative Complications / Q000139:chemically induced / Q000517:prevention & control; D007649:Ketamine / Q000008:administration & dosage* / Q000494:pharmacology*; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control; D010880:Piperidines / Q000009:adverse effects* / Q000037:antagonists & inhibitors*; D000077208:Remifentanil; D013131:Spine / Q000601:surgery
D000759:Adjuvants, Anesthesia; D000894:Anti-Inflammatory Agents, Non-Steroidal; D010880:Piperidines; D007649:Ketamine; D000077208:Remifentanil