Median effective infusion dose (ED50) of alfentanil for monitored anesthesia care of percutaneous vertebroplasty of osteoporotic fractures

Monitored anesthesia care in and outside the operating room

Monitored anesthesia care (MAC) is an anesthesia technique combining local anesthesia with parenteral drugs for sedation and analgesia. The use of MAC is increasing for a variety of diagnostic and therapeutic procedures in and outside of the operating room due to the rapid postoperative recovery with the use of relatively small amounts of sedatives and analgesics compared to general anesthesia. The purposes of MAC are providing patients with safe sedation, comfort, pain control and satisfaction. Preoperative evaluation for patients with MAC is similar to those of general or regional anesthesia in that patients should be comprehensively assessed. Additionally, patient cooperation with comprehension of the procedure is an essential component during MAC. In addition to local anesthesia by operators or anesthesiologists, systemic sedatives and analgesics are administered to provide patients with comfort during procedures performed with MAC. The discretion and judgment of an experienced anesthesiologist are required for the safety and efficacy profiles because the airway of the patients is not secured. The infusion of sedatives and analgesics should be individualized during MAC. Many procedures in and outside of the operating room, including eye surgery, otolaryngologic surgery, cardiovascular procedures, pain procedures, and endoscopy are performed with MAC to increase patient and operator satisfaction.

Percutaneous vertebroplasty and procedural pain

BACKGROUND AND PURPOSE

No consensus exists regarding pain management during PV. In this study, we evaluated the effectiveness of local infiltration anesthesia as the only pain medication.

MATERIALS AND METHODS

From September 2008 to March 2009, 44 consecutive patients (35 women and 9 men; mean age, 74 years) with symptomatic OVCFs were included in the study. Lidocaine was infiltrated to the skin and the periosteum of the pedicle. After PV, patients indicated pain sensation on a VAS. In addition, patients indicated the most painful moment during the procedure: lidocaine infiltration, placing the needles, or cement injection. Finally, patients were asked whether pain medication during the procedure was sufficient. After the procedure the surgeon was asked to judge the expected VAS score of the patient.

RESULTS

Mean VAS score was 5.7 (median, 6; range, 1-10). Seventeen of 44 patients (39%) indicated that lidocaine infiltration was insufficient for procedural pain reduction. The mean VAS score of these patients was 7.3 (range, 5-10). Placing the needles was specified as most painful moment in 29 patients (66%), lidocaine infiltration in 11 (25%), and cement injection in 4 (9%). Surgeons' expectations of patients' VAS scores were a mean of 3.3 (median, 3; range, 1-6).

CONCLUSIONS

For a substantial proportion of patients, local infiltration anesthesia was not sufficient for pain reduction during PV. The severity of pain experienced by the patient is usually not appreciated correctly by the surgeon.