[Controlled hypotension for tympanoplasty: comparison between remifentanil and combination of alfentanil and sodium nitroprusside].

OBJECTIVES

We compared the efficacy of remifentanil and the combination of alfentanil and sodium nitroprusside on controlled hypotension and bleeding at surgical site.

PATIENTS AND METHODS

Thirty ASA I-II patients undergoing tympanoplasty were randomly assigned to remifentanil and alfentanil-sodium nitroprusside groups, equal in number. Anesthesia was induced with remifentanil or alfentanil combined with propofol and rocuronium, and maintained with remifentanil or alfentanil-sodium nitroprusside infusions combined with propofol. All patients were ventilated with a mixture of 33% O2 and 66% N2O. Invasive mean arterial blood pressure, heart rate, peripheral oxygen saturation, the amount of bleeding at surgical site, and blood gas values were recorded.

RESULTS

Controlled hypotension was achieved at a target mean arterial pressure of 60+/-5 mmHg in both groups. Compared to the baseline levels, heart rate values were lower in the remifentanil group (p<0.05), and similar in the sodium nitroprusside group (p>0.05). The amount of bleeding and the dryness of the surgical site were similar in two groups. PaCO2 and pH values differed significantly between the two groups at perioperative 1 and 2 hours and in the postoperative 30th minute (p<0.05), but the difference was not clinically significant.

CONCLUSION

Our results suggest that remifentanil is effective in obtaining controlled hypotension without an additional potent hypotensive agent and provides appropriate surgical conditions by reducing the amount of bleeding.