Use of Sevoflurane Inhalation Sedation for Outpatient Third Molar Surgery: RESULTS

In: Anesthesia

6 Mar 2010

Twenty-four patients were initially enrolled in the study. One patient, a 25-year-old, 80-kg woman, developed nausea after 2 minutes of sevoflurane administration at a final vaporizer setting of 0.5%. After 3 to 4 minutes, her feeling of nausea subsided. The patient was withdrawn from the study. A conscious sedation was then planned and 10 mg of diazepam was slowly titrated. Shortly thereafter, the patient reported that she felt more relaxed but she again became nauseated and vomited. After emesis of a small volume of gastric liquid, 25 mg of promethazine was titrated. Nausea was relieved and the patient felt she could proceed with her planned surgery, which was carried out uneventfully.

The remaining 23 patients successfully completed the entire experimental protocol. The 2 treatment groups were remarkably similar in character. Table 1 outlines the treatment groups. Between-group parameters of age and weight were not statistically significant between groups; nor were surgery times. silagra 100

Table 1. Characteristics of the 2 Treatment Groups




P Value

Age in years, mean ± standard deviation SexWeight in kilograms, mean ± standard deviation Surgery time in minutes, mean ± standard deviation 22.9 ± 3.42 F = 7, M = 464.3            ± 10.9

30.4            ± 12.5

22.5 ± 3.63 F = 9, M = 3 66.5 ± 12.7 25.4 ± 13.8 .7841 .6670 .6578 .3804

The time to transfer to the recovery room was not significantly different between the 2 groups: 12.3 ± 2.83 minutes for the sevoflurane group versus 13.6 ± 4.76 minutes for the propofol group from the time the surgery was stopped and the appropriate anesthetic discontinued. It should be noted that in this outpatient facility, patients are required to walk approximately 4.5 meters to a recovery room bed with only guided assistance.

All patients were equally amnestic for their surgical procedures with either sedative technique as measured by both memory cards and questionnaire. No patient recalled the cards shown to them during these stages of the protocol. Additionally, the questionnaire filled out by the patient the day following the procedure revealed that no patient remembered the local anesthetic injections and one person in each group did recall some aspects of the surgery, but none noted pain (see questions 2 and 3).

Table 2. Weighted Trieger Test Scores for the 2 Experimental Groups


Trieger Test

Sevoflurane     Propofol P Value


0.0 ± 1.0      0.0 ± 0.0



None completed


None completed


0.0 ± 2.0      2.5 ± 2.0



0.0 ± 1.0      0.0 ± 1.5



0.0 ± 1.0     0.0 ± 0.5



0.0 ± 0.0     0.0 ± 0.0


Trieger test scores are shown in Table 2. A baseline Trieger test after the IV was started but before sedative administration revealed no significant differences between groups. Trieger tests were again administered after deep sedation was achieved but just prior to local anesthetic injection and at the conclusion of surgery. No patient was able to complete the Trieger test at these intervals. The test was attempted once again after pa­tients could open their eyes with effort. Some patients were able to grasp the pen but none were able to hold the pen or focus on the Trieger test form. Psychomotor recovery was assessed with the Trieger test at 10, 20, 30, and 40 minutes following discontinuation of the appropriate sedative drug. No statistically significant differences were found at any of these times. Three patients, 1 in the sevoflurane group and 2 in the propofol group, were unable to complete the Trieger test at the 10-minute postoperative interval. canadian discount drugs

Subjective recovery was assessed by the questionnaire’s questions 4 and 5, which asked if sedative effects lingered the day of surgery or if they persisted to the following day. Four of 9 patients in each sedative group experienced lingering effects of the sedative after leaving the oral surgery clinic. However, although one patient who received sevoflurane answered that the sedative effects lingered the day of surgery, the effect he indicated was that his “lip was numb.” All but one patient responded that the sedative effects had worn off the next day; the single person who responded otherwise was in the sevoflurane group, and this person did not elaborate on what sedative effects persisted. In any case, there were no statistically significant differences between groups.

Physiological parameters of systolic blood pressure, diastolic blood pressure, and heart rate all measured as a positive and negative percentage change from baseline were calculated and analyzed. Additionally, lowest oxygen saturation as measured by pulse oximetry was recorded. No statistically different percentage changes in blood pressure or heart rate were seen between groups. Additionally, the lowest recorded oxygen saturation was 98%, with no difference noted between groups (Table 3).

Table 3. Physiological Parameters of the 2 Experimental Groups

Variable* Sevoflurane Propofol

P Value

+Af Systolic blood pressure, mm Hgtt 5.89 ± 6.25


-f- 11.7


-Д Systolic blood pressure, mm Hgtt 14.4 ± 8.20


± 9.43


+Д Diastolic mm Hgtt 7.22 ± 11.5


± 24.8


-Д Diastolic blood pressure, mm Hgtt 25.0 ±9.11




+Д Heart rate, bpmt 6.89 ± 6.66




—Д Heart rate, bpmt 19.2 ± 8.03




Lowest oxygen saturation SP02 99.8 ± 0.441




The quality of the sedation was rated independently by the blinded patient, the blinded surgeon, and the un-blinded dentist anesthesiologist by use of a 100-mm visual analog scale (Table 4). No individual was able to see another individual’s VAS score. With a median VAS of 82 for the sevoflurane group versus 95.5 for the propofol group, no statistically significant difference was noted in the surgeon’s evaluation of the sedative procedure. The dentist anesthesiologist’s rating of the 2 sedatives with the propofol sedative (median VAS = 92) being preferred over the sevoflurane sedative (median VAS = 79) approached significance with P < 0.06.

Table 4. Patients’ Visual Analog Scale as Measured By Clinical Personnel and Self-Reporting

Visual Analog
Scale Sevoflurane


P Value

Anesthesiologist 79.0 ± 21.0

92.0 ± 9.5


Surgeon 82.0 ± 30.0

95.5 ± 8.5


Patient 100 ± 10.0

96.0 ± 9.0


Patient 92.0 ± 13.0

96.0 ± 10.0



Patient VAS scores for overall satisfaction of the sedative were taken just before patients were discharged and also were included in the postoperative questionnaire completed the day after surgery. Median values indicated high acceptance of both sedative procedures at discharge and the following day (Table 4). The lowest median VAS score for any patient group was 95. Patient satisfaction with the sedative techniques was further corroborated by the results of the questionnaire’s question 6, which asked whether patients would desire the same sedative for a similar procedure. Twenty-two of the 23 participants responded affirmatively. The lone dissenter was the one patient in the sevoflurane group who completed the study and who experienced postsedation nausea.


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