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June 1998
Fast-Track Eligibility
After Ambulatory Anesthesia: A Comparison of Desflurane, Sevoflurane, and
Propofol.
Song D, Joshi GJ, White
PF.
Anesth Analg. 1998;86:267-73.
[ see abstract below ]
Most studies comparing newer anesthetic agents with older ones in outpatient settings have attributed improved earlier awakening times, but not reductions in postanesthesia care unit (PACU) or facility discharge times, to the newer agents. We have come to understand that in order to truly reap the benefits of the newer agents, we need to change how we care for patients during the recovery process. Fast-tracking represents one such change, and one step toward the goal of improved ambulatory anesthesia.
Fast-tracking is the term for transferring patients from the operating room directly to the Phase II recovery area, bypassing the traditional first-stage PACU. This study compared three of the newer agents for anesthesia maintenance - desflurane, sevoflurane and propofol - with regard to their relative abilities to facilitate fast-track eligibility.
The authors studied 120 women undergoing laparoscopic tubal ligation. Each received IV midazolam (2 mg), propofol (2 mg/kg), intubation after succinylcholine and fentanyl (2 µg/kg). Patients were randomly assigned to maintenance anesthesia with desflurane (initially 3%), sevoflurane (initially 1.25%), or propofol (initially 100 µg/kg/min), in combination with 60% nitrous oxide. The maintenance anesthetic dose was titrated to maintain hemodynamic variables within 15% of preinduction baseline values. Boluses of mivicurium (0.04 �g/kg) could also be given. Patients also received ketorolac (30 mg) and droperidol (0.625 mg) approximately 15 minutes before the end of surgery, and bupivacaine (0.25%) was injected at the instrument portals. Maintenance anesthetic agents were discontinued when the laparoscope was removed, and nitrous oxide was discontinued after the last suture. The three anesthetic study groups were comparable with respect to demographic characteristics, physical status, duration of anesthesia (~ 70 minutes) and duration of surgery (~ 45 minutes). At the end of surgery, the agent concentrations were 1.03 � 0.6 MAC desflurane, 1.04 � 0.5 MAC sevoflurane and 81 � 23 µg/kg/min propofol.
The recovery times for awakening, extubation and orientation were significantly shorter in the desflurane and sevoflurane groups compared with the propofol group. Readiness for discharge from the PACU I was determined by the Aldrete score. Patients who were awake, fully oriented and comfortable, with stable cardiovascular and respiratory variables (recovery score of 10) were considered to be fast-track eligible. On arrival in the PACU, a significantly higher percentage of the patients receiving inhaled agents were judged to be fast-track eligible: 90% and 75% for desflurane and sevoflurane, respectively, vs. 26% for propofol. Aldrete scores of 10 were achieved significantly sooner in the desflurane and sevoflurane groups (10.0 and 11.7 minutes, respectively), compared with the propofol group (15.7 minutes). There were no significant differences between the inhaled agents for any parameter studied. The actual duration for PACU stay was similar in all groups, 33-39 minutes. There were no differences between the three groups in intermediate recovery times: oral intake (~ 1 hr), duration for Phase II Unit stay (~ 2 hr.), and home readiness. There were also no significant differences between the three groups with regard to use of analgesics, antiemetics or postoperative nausea and vomiting (PONV) treatment resources in the three treatment groups.
Further examination of the Aldrete scores provides additional information about the timing of fast-track eligibility. At 3 minutes after anesthesia, there was a higher recovery score in the desflurane group compared to the other two groups (6 vs. 4), but by 5 and 10 minutes after anesthesia, desflurane and sevoflurane were associated with significantly higher scores than was propofol. The incidence of PONV was highest in the desflurane group and lowest in the propofol group, although the differences were not statistically significant.
The authors highlight the point that this study assesses fast-tracking eligibility. In their institution, a mandatory PACU stay of 30 minutes is required, and this is the reason for the difference between the times to achieving Aldrete = 10 and actual PACU discharge. It is also important to note, when comparing studies about fast-tracking, that different institutions have different capabilities for PACU II. In some facilities, the patient needs to be stable on a stretcher for transfer to an area with lower nursing acuity; in other institutions, the patient needs to be able to leave the operating room in a wheelchair. All of the above advances are worthwhile savings, from both the patient's and the institution's points of view. For the institutions, the ability to care for patients in an area with a lower personnel-patient ratio can provide significant cost savings. For the patients, every improvement in their well being after anesthesia, and the speed at which those improvements occur, is certainly appreciated.
Return to the Current Literature Review Front Page, or read the abstract:
ABSTRACT
This study was designed to test the hypothesis that using the less soluble volatile anesthetics, desflurane and sevoflurane, as alternatives to propofol for maintenance of anesthesia facilitates the ability of outpatients to achieve postanesthesia care unit (PACU) discharge criteria (i.e., fast-track eligibility) on arrival in the PACU after laparoscopic surgery.
One hundred-twenty consenting women undergoing laparoscopic tubal ligation procedures were randomly assigned to one of three treatment groups. After a standardized induction of anesthesia and tracheal intubation sequence, anesthesia was maintained with either desflurane 2%-6%, sevoflurane 0.6%-1.75%, or propofol 50-150 microg x kg(-1) x min(-1) in combination with nitrous oxide 60% in oxygen. Recovery times, postanesthesia recovery scores, and the number and type of therapeutic interventions in the PACU were recorded.
Compared with the propofol group, the times to awakening and to achieve a recovery score of 10 were significantly shorter, and the percentage of patients judged fast-track eligible on arrival in the PACU was significantly higher, in the desflurane and sevoflurane groups (90% and 75% vs 26%).
In conclusion, compared with propofol, the use of desflurane and sevoflurane for the maintenance of general anesthesia resulted in a higher percentage of patients being judged fast-track eligible after outpatient laparoscopic tubal ligation procedures.
Implications: Bypassing the recovery room by transferring outpatients directly to the step-down unit after ambulatory surgery ("fast-tracking") could result in significant cost-savings. We examined the effects of three different maintenance anesthetics--desflurane, sevoflurane, and propofol--on the fast-track eligibility of outpatients after laparoscopic tubal ligation surgery. Compared with propofol, desflurane and sevoflurane resulted in a higher percentage of outpatients being judged eligible for fast-tracking.
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