What is new in monitored anesthesia care?

A Comparison of Retrobulbar Block, Sub-Tenon Block, and Topical Anesthesia during Cataract Surgery

Purpose

This randomized, double-blinded, prospective study was performed to compare the intraoperative hemodynamic variables and the patient-reported outcomes, such as intra- and postoperative analgesia and patient satisfaction, of retrobulbar block, sub-Tenon block, and topical anesthesia during cataract surgery under monitored anesthesia care.

Methods

Eighty-one patients, ASA physical status I–III, undergoing elective cataract surgery under monitored anesthesia care, aged between 43 and 78 years, were randomly assigned to three groups: retrobulbar block (group R), sub-Tenon block (group S), or topical anesthesia (group T). Three minutes after the start of monitored anesthesia care with lidocaine-propofol-remifentanil mixture, an ophthalmologist performed regional anesthesia. Intraoperative hemodynamics, pain score, and patients' satisfaction with the anesthetic experiences were recorded by a study-blinded anesthesiologist.

Results

Mean arterial pressure and heart rate in group R were significantly higher than those in groups S and T during and just after the regional block (p<0.05). Group R required smaller dosage of patient controlled sedation and fewer supplemental bolus doses than groups S and T (p<0.05). On the other hand, group S showed the highest satisfaction scores among the three groups (p<0.05).

Conclusions

Sub-Tenon block seems to be better than retrobulbar block and topical anesthesia in patient satisfaction though adequate analgesia was achieved after retrobulbar block during cataract surgery under monitored anesthesia care.

Monitored Anesthesia Care with Target-Controlled Infusion in Vibroplasty

Objectives:

Correct positioning of a floating mass transducer during middle ear implant surgery is often problematic. With the use of monitored anesthesia care (MAC), however, deep sedation is maintained during surgery, followed by conscious sedation in which the patient can respond to test questions that investigate correct device position and function. The main aim of this study was to determine whether intraoperative audiometric assessment was feasible with MAC with target-controlled infusion in vibroplasty. An additional aim was to determine whether MAC was sufficiently comfortable for patients during the procedure.

Methods:

The study group comprised 8 patients who underwent vibroplasty under sedation. Before suturing, audiometric assessment was done by stimulating the external auditory processor with pure tones at 0.5, 1, 2, and 4 kHz. Blood pressure, arterial oxygen saturation level, heart rate, and end tidal carbon dioxide level were monitored during the procedure and at awakening.

Results:

Audiometric assessment was successfully completed in all 8 patients. The selected parameters indicated that no patient experienced pain or discomfort during surgery; the absence of discomfort was confirmed 1 to 2 hours after the operation by simple questioning.

Conclusions:

We found MAC to be an efficient and relatively safe technique for verifying the correct coupling of the floating mass transducer with the middle ear during vibroplasty. The patients were able to respond appropriately to questions and commands; moreover, none reported having experienced pain or discomfort during the operation.

Remifentanil-propofol versus fentanyl-propofol for monitored anesthesia care during hysteroscopy

STUDY OBJECTIVE

To compare the efficacy of remifentanil-propofol with that of fentanyl-propofol for monitored anesthesia care during hysteroscopy.

DESIGN

Prospective, randomized study.

SETTING

Operating room and postanesthesia care unit of a university hospital.

PATIENTS

30 ASA physical status I and II adult patients undergoing hysteroscopic procedures.

INTERVENTIONS

After propofol infusion, patients received a bolus of remifentanil (group R, 0.5 microg/kg) or fentanyl (group F, 1 microg/kg) 4 minutes before starting the procedure and then received a continuous infusion of remifentanil (group R, 0.05 microg/kg per min) or bolus doses of fentanyl (group F, 0.5 microg/kg).

MEASUREMENTS AND MAIN RESULTS

Patients in group R had lower pain scores than patients in group F (0-0 vs 0-7, P < 0.05) and more stable blood pressures (74 +/- 15 vs 85 +/- 9 mmHg, P < 0.05) one minute after the start of the procedure. However, no differences were observed in other variables (recovery profiles and satisfaction scores).

CONCLUSION

Remifentanil seems to be a safe and effective analgesic adjunct for monitored anesthesia care of hysteroscopic surgery.

A comparison of midazolam and midazolam with remifentanil for patient-controlled sedation during operations on third molars

Our aim was to compare patients' satisfaction and cooperation, and clinical efficacy, of midazolam alone, and midazolam and remifentanil for patient-controlled sedation during removal of third molars. Forty patients, American Society of Anesthesiologists grades I and II, admitted for extraction of impacted mandibular third molars were included in this randomised, prospective study. They were given an intravenous bolus of midazolam 0.03 mg/kg and then allowed to use patient-controlled sedation. In the midazolam group, 2 ml of 0.5 mg/ml midazolam was given automatically. In the midazolam-remifentanil group, 2 ml of 0.5 mg/ml midazolam and 12.5 microg/ml remifentanil were given in the same manner. The lockout period was 5 min. Vital signs and oxygen saturation were recorded. Patients' and surgeons' satisfaction, and the patients' degree of amnesia about the local anaesthetic, drilling, removal of the tooth, and pain during extraction were also assessed. There were no significant differences between systolic and diastolic blood pressures during sedation, but heart rate after 30 min in the combined group was significantly lower than in the midazolam group (p<0.05). Surgeons described the midazolam group as excellent in 9 and good in 11. In the combined group, satisfaction was excellent in 11, good in 7, and satisfactory or unacceptable in 1 of each. Immediately postoperatively, 19 patients in each group ranked their satisfaction as excellent and 1 as good. Twenty-four hours later it was unchanged in the midazolam group, while 15 patients in the other group thought it was excellent, 3 good, and 2 poor. Patient-controlled analgesia with midazolam or midazolam and remifentanil is safe and reliable during extraction of third molars.