The use of monitored anesthesia care (MAC) as the technique of choice for a variety of invasive or noninvasive procedures is increasing. The purpose of this study to compare the outcomes of two different methods, spinal anesthesia and ilioinguinal-hypogastric nerve block (IHNB) with target concentrated infusion of remifentanil for inguinal herniorrhaphy.

Fifty patients were assigned to spinal anesthesia (Group S) or IHNB with MAC group (Group M). In Group M, IHNB was performed and the effect site concentration of remifentanil, starting from 2 ng/ml, was titrated according to the respiratory rate or discomfort, either by increasing or decreasing the dose by 0.3 ng/ml. The groups were compared to assess hemodynamic values, oxygen saturation, bispectral index (BIS), observer assessment alertness/sedation scale (OAA/S), visual analogue scale (VAS) for pain score and patients' and surgeon's satisfaction.

BIS and OAA/S were not significantly different between the two groups. Hemodynamic variables were stable in Group M. Thirteen patients in the same group showed decreased respiratory rate without desaturation, and recovered immediately by encouraging taking deep breaths without the use of assist ventilation. Although VAS in the ward was not significantly different between the two groups, interestingly, patients' and surgeon's satisfaction scores (P = 0.0004, P = 0.004) were higher in Group M. The number of the patients who suffered from urinary retention was higher in Group S (P = 0.0021).

IHNB under MAC with remifentanil is a useful method for inguinal herniorrhaphy reflecting hemodynamic stability, fewer side effects and higher satisfaction. This approach can be applied for outpatient surgeries and patients who are unfit for spinal anesthesia or general anesthesia.