Six studies could be included with relevant data examining a total of 634 patients undergoing a variety of ambulatory surgical procedures (47–52) (Table 4). Statistically significant differences were found in the “time to opening eyes,” “time to obeying commands,” “time to transfer from Phase 1 to Phase II recovery,” “home readiness” (P < 0.00001), and “home discharge” (P = 0.05). The results of the latter are, however, based on only two studies. The WMD in all the recovery indices (early and intermediate recovery) between sevoflurane and isoflurane were small and in favor of sevoflurane (Table 6). Drowsiness was significantly more frequent with isoflurane compared with sevoflurane in the postoperative period (P = 0.03) but no other significant differences were found in the incidence of postoperative complications.
When data were combined into an inhaled group (isoflurane, desflurane, and sevoflurane) and compared with an IV group (propofol), the incidence of PON was 25.8% and 14.1% respectively (NNT, 8.6), POV was 14.1% and 5.2% respectively (NNT, 11.2), and the need for antiemetics was 16.6% and 5.1% respectively (NNT, 8.7). Similarly, the incidence of postdischarge nausea in the inhaled versus IV groups was 21.5% versus 13.5% (NNT, 12.5), and the incidence of postdischarge vomiting was 15.6% versus 5.9% (NNT, 10.3) respectively.
In this systematic analysis of the literature, we found that early recovery, characterized by opening eyes and obeying commands, was statistically significantly different, but only marginally quicker, in desflurane and sevoflurane compared with isoflurane or propofol groups. Intermediate recovery characterized by home readiness was slightly earlier in the sevoflurane group compared with isoflurane group alone. Postoperative complications, specifically PON and POV, were significantly less frequent in the propofol group compared with isoflurane, sevoflurane, and desflurane groups.
No significant difference in early recovery was found when isoflurane or propofol was used for the maintenance of anesthesia. Although we found significant differences in early recovery between sevoflurane/desflurane compared with propofol/isoflurane in favor of the former, the magnitude of these differences was small (<5 min) and therefore of doubtful clinical relevance even in a busy ambulatory unit. The small differences between these anesthetics were seen following strict protocols and not allowing stepwise reduction in anesthetic concentration towards the end of surgery, which is normal clinical practice. Despite the low blood:gas partition coefficient of desflurane and sevoflurane with the theoretical advantage of rapid recovery from anesthesia, these anesthetics have provided only marginally better early recovery characteristics compared with propofol or isoflurane. One explanation for this could be that in most studies a combination of drugs is used. Therefore, residual effects of drugs used for premedication, opiates, and muscle relaxants may interact with the anesthetics to delay the onset of early recovery. Another reason for these minor differences could be that the depth of anesthesia at the end of the operation was unknown. Most studies have used clinical assessment of anesthetic depth based on hemodynamic responses to pain during anesthesia and therefore it is easy to err on maintaining patients deeply anesthetized, which in turn affects recovery. Indeed, recent studies using bispectral index (BIS) as a guide to anesthetic depth have shown that a large number of patients can be “fast-tracked” when anesthetic depth is monitored (4). Consequently, appropriate depth of anesthesia is an important factor in quick recovery after ambulatory surgery, a factor that has not been used to advantage in most published studies.
Our analysis demonstrated that sevoflurane was associated with an earlier home readiness (5 min) compared with isoflurane, with no differences among the other comparison of inhaled anesthetics or against propofol. However, propofol was associated with earlier (10–15 min) home discharge compared with sevoflurane/isoflurane. Similarly, sevoflurane was associated with a difference of 25 min in home discharge when compared with isoflurane. However, the latter findings were based on two studies with wide CI, and borderline statistical significance.
In interpreting differences in home readiness and discharge, it is critical to understand the factors influencing the interpretation of each outcome. “Home readiness” is the time when patients are ready to be discharged home as assessed by standardized methods such as the modified postanesthesia discharge scoring system, whereas “home discharge” is the actual time when the patient could leave the hospital. The latter is affected by many non-medical factors such as absence of an adult to accompany the patient home or waiting to meet the doctor before going home. Unfortunately, many authors have not made a distinction between these variables and it sometimes remains unclear which variable is actually being measured. Other factors such as duration and type of surgery and local hospital practices and routines may affect home discharge and may sometimes be more important than the choice of the anesthetic used. For instance, some hospitals use local anesthetics routinely into surgical wounds, which may reduce postoperative narcotic requirements, which in turn may affect discharge. Other hospitals require patients to empty their bladders before being considered home ready, which may also affect discharge times. Rapid early recovery may also be associated with a greater appreciation of pain in the early postoperative period, which increases postoperative analgesic requirement and thus delays recovery, a finding seen by Robinson et al. (56) in their meta-analysis of sevoflurane versus propofol. Recovery profiles can also be influenced by concomitant analgesics used preoperatively and the depth of anesthesia attained towards the end of the operation. For example, differences in recovery and home discharge have been found when using alfentanil or fentanyl as analgesics (57). Some authors have suggested that using BIS for depth of anesthesia monitoring may enhance recovery (4). However, using a standardized anesthetic regimen and strict discharge criteria, Ahmad et al. (58) showed that BIS monitoring does not have a significant effect on the ability to fast track outpatients. In addition, although more patients may be fast track eligible using desflurane or sevoflurane compared with propofol for maintenance of anesthesia (2), the number of patients who actually bypass the PACU is much smaller because of anesthetic-related factors such as residual sedation (34). All these confounding factors need to be considered when making a case for the use of a specific anesthetic for the maintenance of anesthesia in ambulatory surgical patients.
Postoperative nausea and vomiting (PONV) were significantly more common with inhaled anesthetics compared with propofol, and the use of antiemetics was also more common with inhaled anesthetics. The incidence of PDNV was also less frequent with propofol compared with isoflurane but not desflurane or sevoflurane. Tramer et al. (59) in a meta-analysis found that maintenance of anesthesia with propofol is an advantage compared with other anesthetics when the incidence of complications is in the range of 20%–60%, with NNT of <5. The incidence of PON was 25%–38% in our present analysis, which would support the use of propofol infusion. However, the efficacy of propofol for reducing PONV was small compared with the inhaled anesthetics, which may question the use of propofol alone without antiemetic prophylaxis in patients at risk. Other than headache, which occurred with more frequency with isoflurane compared with propofol, and drowsiness, which occurred with a significantly more frequency with isoflurane compared with sevoflurane, no other significant differences were found in the incidence of postoperative complications.
There are a number of limitations in our meta-analysis. Although we conducted a thorough review of work published in the English language, there may be additional references not identified in our search strategies. Many authors did not state whether the patients studied were inpatients or outpatients. Whenever in doubt, we came to a consensus as to the study group. When authors had not specifically stated whether the data pertained to PON or POV, we decided to exclude these data from the analysis. This limits the number of patients studied, but we chose to report PDNV as distinct end-points. We included patients who were administered nitrous oxide was administered for maintenance in the IV anesthesia group because we believe that this is a common practice used in many studies. Excluding these studies would reduce the scope of this systematic review as well as limiting our findings to a very small and distinct population. Patients induced with inhaled anesthetic (e.g., desflurane and sevoflurane) were also excluded from our review, as this could affect the primary end-points. Finally, we only analyzed studies published in the English language, which can also be considered as a bias. Many authors publish “negative” findings in local (non-English language) journals (60), which would suggest that the differences found by us may be larger than the true differences among these anesthetics, which is further support that the overall differences between the inhaled anesthetics are probably very small.
In conclusion, the choice of anesthetic for maintenance of anesthesia should be guided by the training and experience of the individual physician, as well as the routines and equipment available in the hospital, because the specific anesthetic appears to play a minor role in outcome after ambulatory surgery.
We would like to thank the staff at the Welch Medical Library, Johns Hopkins Medical Institutions for the support in retrieving articles for the study. We would also like to thank the Olof Norlander Memorial Fund for financial support of this project.
1. Apfelbaum JL, Walawander CA, Grasela TH, et al. Eliminating intensive postoperative care in same-day surgery patients using short-acting anesthetics. Anesthesiology 2002; 97: 66–74.
2. Song D, Joshi GP, White PF. Fast-track eligibility after ambulatory anesthesia: a comparison of desflurane, sevoflurane, and propofol. Anesth Analg 1998; 86: 267–73.
3. Nathan N, Peyclit A, Lahrimi A, Feiss P. Comparison of sevoflurane and propofol for ambulatory anaesthesia in gynaecological surgery. Can J Anaesth 1998; 45: 1148–50.
4. Song D, van Vlymen J, White PF. Is the bispectral index useful in predicting fast-track eligibility after ambulatory anesthesia with propofol and desflurane? Anesth Analg 1998; 87: 1245–8.
5. Van Hemelrijck J, Smith I, White PF. Use of desflurane for outpatient anesthesia: a comparison with propofol and nitrous oxide. Anesthesiology 1991; 75: 197–203.
6. Dexter F, Tinker JH. Comparisons between desflurane and isoflurane or propofol on time to following commands and time to discharge: a metaanalysis. Anesthesiology 1995; 83: 77–82.
7. Wilhelm W, Grundmann U, Van Aken H, et al. A multicenter comparison of isoflurane and propofol as adjuncts to remifentanil-based anesthesia. J Clin Anesth 2000; 12: 129–35.
8. Ashworth J, Smith I. Comparison of desflurane with isoflurane or propofol in spontaneously breathing ambulatory patients. Anesth Analg 1998; 87: 312–8.
9. Gupta A, Kullander M, Ekberg K, Lennmarken C. Assessment of recovery following day-case arthroscopy: a comparison between propofol and isoflurane-based anaesthesia. Anaesthesia 1995; 50: 937–42.
10. Valanne J. Recovery and discharge of patients after long propofol infusion versus isoflurane anaesthesia for ambulatory surgery. Acta Anaesthesiol Scand 1992; 36: 530–3.
11. Nightingale JJ, Lewis IH. Recovery from day-case anaesthesia: comparison of total IV anaesthesia using propofol with an inhalation technique. Br J Anaesth 1992; 68: 356–9.
12. Sung YF, Reiss N, Tillette T. The differential cost of anesthesia and recovery with propofol-nitrous oxide anesthesia versus thiopental sodium-isoflurane-nitrous oxide anesthesia. J Clin Anesth 1991; 3: 391–4.
13. Werner ME, Bach DE, Newhouse RF. A comparison of propofol with methohexital and isoflurane in two general anesthetic techniques. J Oral Maxillofac Surg 1993; 51: 1076–9.
14. Korttila K, Ostman P, Faure E, et al. Randomized comparison of recovery after propofol-nitrous oxide versus thiopentone-isoflurane-nitrous oxide anaesthesia in patients undergoing ambulatory surgery. Acta Anaesthesiol Scand 1990; 34: 400–3.
15. Pollard BJ, Bryan A, Bennett D, et al. Recovery after oral surgery with halothane, enflurane, isoflurane or propofol anaesthesia. Br J Anaesth 1994; 72: 559–66.
16. Moffat A, Cullen PM. Comparison of two standard techniques of general anaesthesia for day-case cataract surgery. Br J Anaesth 1995; 74: 145–8.
17. Larsen LE, Gupta A, Ledin T, et al. Psychomotor recovery following propofol or isoflurane anaesthesia for day-care surgery. Acta Anaesthesiol Scand 1992; 36: 276–82.
18. Marshall CA, Jones RM, Bajorek PK, Cashman JN. Recovery characteristics using isoflurane or propofol for maintenance of anaesthesia: a double-blind controlled trial. Anaesthesia 1992; 47: 461–6.
19. Visser K, Hassink EA, Bonsel GJ, et al. Randomized controlled trial of total intravenous anesthesia with propofol versus inhalation anesthesia with isoflurane-nitrous oxide: postoperative nausea with vomiting and economic analysis. Anesthesiology 2001; 95: 616–26.
20. Milligan KR, O’Toole DP, Howe JP, et al. Recovery from outpatient anaesthesia: a comparison of incremental propofol and propofol-isoflurane. Br J Anaesth 1987; 59: 1111–4.
21. Collins SJ, Robinson AL, Holland HF. A comparison between total intravenous anaesthesia using a propofol/alfentanil mixture and an inhalational technique for laparoscopic gynaecological sterilization. Eur J Anaesthesiol 1996; 13: 33–7.
22. Lim BL, Low TC. Total intravenous anaesthesia versus inhalational anaesthesia for dental day surgery. Anaesth Intensive Care 1992; 20: 475–8.
23. Alhashemi JA, Miller DR, O’Brien HV, Hull KA. Cost-effectiveness of inhalational, balanced and total intravenous anaesthesia for ambulatory knee surgery. Can J Anaesth 1997; 44: 118–25.
24. Zuurmond WW, van Leeuwen L, Helmers JH. Recovery from propofol infusion as the main agent for outpatient arthroscopy: a comparison with isoflurane. Anaesthesia 1987; 42: 356–9.
25. Tang J, White PF, Wender RH, et al. Fast-track office-based anesthesia: a comparison of propofol versus desflurane with antiemetic prophylaxis in spontaneously breathing patients. Anesth Analg 2001; 92: 95–9.
26. Rapp SE, Conahan TJ, Pavlin DJ, et al. Comparison of desflurane with propofol in outpatients undergoing peripheral orthopedic surgery. Anesth Analg 1992; 75: 572–9.
27. Lebenbom-Mansour MH, Pandit SK, Kothary SP, et al. Desflurane versus propofol anesthesia: a comparative analysis in outpatients. Anesth Analg 1993; 76: 936–41.
28. Eriksson H, Korttila K. Recovery profile after desflurane with or without ondansetron compared with propofol in patients undergoing outpatient gynecological laparoscopy. Anesth Analg 1996; 82: 533–8.
29. Raeder JC, Mjaland O, Aasbo V, et al. Desflurane versus propofol maintenance for outpatient laparoscopic cholecystectomy. Acta Anaesthesiol Scand 1998; 42: 106–10.
30. Wrigley SR, Fairfield JE, Jones RM, Black AE. Induction and recovery characteristics of desflurane in day case patients: a comparison with propofol. Anaesthesia 1991; 46: 615–22.
31. Song D, Chung F, Wong J, Yogendran S. The assessment of postural stability after ambulatory anesthesia: a comparison of desflurane with propofol. Anesth Analg 2002; 94: 60–4.
32. Graham SG, Aitkenhead AR. A comparison between propofol and desflurane anaesthesia for minor gynaecological laparoscopic surgery. Anaesthesia 1993; 48: 471–5.
33. Larsen B, Seitz A, Larsen R. Recovery of cognitive function after remifentanil-propofol anesthesia: a comparison with desflurane and sevoflurane anesthesia. Anesth Analg 2000; 90: 168–74.
34. Coloma M, Zhou T, White PF, et al. Fast-tracking after outpatient laparoscopy: reasons for failure after propofol, sevoflurane, and desflurane anesthesia. Anesth Analg 2001; 93: 112–5.
35. Tang J, Chen L, White PF, et al. Recovery profile, costs, and patient satisfaction with propofol and sevoflurane for fast-track office-based anesthesia. Anesthesiology 1999; 91: 253–61.
36. Smith I, Thwaites AJ. Target-controlled propofol versus sevoflurane: a double-blind, randomised comparison in day-case anaesthesia. Anaesthesia 1999; 54: 745–52.
37. Fredman B, Nathanson MH, Smith I, et al. Sevoflurane for outpatient anesthesia: a comparison with propofol. Anesth Analg 1995; 81: 823–8.
38. Peduto VA, Peli S, Amicucci G, et al. Maintenance of and recovery from anaesthesia in elderly patients. A clinical comparison between sevoflurane and isoflurane. Minerva Anestesiol 1998; 64 (Suppl3): 18–25.
39. Raeder J, Gupta A, Pedersen FM. Recovery characteristics of sevoflurane- or propofol-based anaesthesia for day-care surgery. Acta Anaesthesiol Scand 1997; 41: 988–94.
40. Smith I, Terhoeve PA, Hennart D, et al. A multicentre comparison of the costs of anaesthesia with sevoflurane or propofol. Br J Anaesth 1999; 83: 564–70.
41. Jellish WS, Lien CA, Fontenot HJ, Hall R. The comparative effects of sevoflurane versus propofol in the induction and maintenance of anesthesia in adult patients. Anesth Analg 1996; 82: 479–85.
42. Wandel C, Neff S, Bohrer H, et al. Recovery characteristics following anaesthesia with sevoflurane or propofol in adults undergoing outpatient surgery. Eur J Clin Pharmacol 1995; 48: 185–8.
43. Nathan N, Peyclit A, Lahrimi A, Feiss P. Comparison of sevoflurane and propofol for ambulatory anaesthesia in gynaecological surgery. Can J Anaesth 1998; 45: 1148–50.
44. Gupta A, Kullander M, Ekberg K, Lennmarken C. Anaesthesia for day-care arthroscopy: a comparison between desflurane and isoflurane. Anaesthesia 1996; 51: 56–62.
45. Ghouri AF, Bodner M, White PF. Recovery profile after desflurane-nitrous oxide versus isoflurane-nitrous oxide in outpatients. Anesthesiology 1991; 74: 419–24.
46. Rieker LB, Rieker MP. A comparison of the recovery times of desflurane and isoflurane in outpatient anesthesia. AANA J 1998; 66: 183–6.
47. Smith CE, Lever JS, Sawkar S, et al. Sevoflurane-N2
O versus propofol/isoflurane-N2
O during elective surgery using the laryngeal mask airway in adults. J Clin Anesth 2000; 12: 392–6.
48. Sloan MH, Conard PF, Karsunky PK, Gross JB. Sevoflurane versus isoflurane: induction and recovery characteristics with single-breath inhaled inductions of anesthesia. Anesth Analg 1996; 82: 528–32.
49. O’Hara DA, DeAngelis V, Lee H, Zedie N, et al. The effects of sevoflurane and isoflurane on recovery from outpatient surgery. Pharmacotherapy 1996; 16: 446–52.
50. Eriksson H, Haasio J, Korttila K. Recovery from sevoflurane and isoflurane anaesthesia after outpatient gynaecological laparoscopy. Acta Anaesthesiol Scand 1995; 39: 377–80.
51. Philip BK, Kallar SK, Bogetz MS, et al. A multicenter comparison of maintenance and recovery with sevoflurane or isoflurane for adult ambulatory anesthesia. Anesth Analg 1996; 83: 314–9.
52. Elcock DH, Sweeney BP. Sevoflurane versus isoflurane: a clinical comparison in day surgery. Anaesthesia 2002; 57: 52–6.
53. Nathanson MH, Fredman B, Smith I, White PF. Sevoflurane versus desflurane for outpatient anesthesia: a comparison of maintenance and recovery profiles. Anesth Analg 1995; 81: 1186–90.
54. Naidu-Sjosvard K, Sjoberg F, Gupta A. Anaesthesia for videoarthroscopy of the knee: a comparison between desflurane and sevoflurane. Acta Anaesthesiol Scand 1998; 42: 464–71.
55. Tarazi EM, Philip BK. A comparison of recovery after sevoflurane or desflurane in ambulatory anesthesia. J Clin Anesth 1998; 10: 272–7.
56. Robinson BJ, Uhrich TD, Ebert TJ. A review of recovery from sevoflurane anaesthesia: comparisons with isoflurane and propofol including meta-analysis. Acta Anaesthesiol Scand 1999; 43: 185–90.
57. Gupta A, Vegfors M, Odensten M, Lennmarken C. Alfentanil or fentanyl during isoflurane-based anaesthesia for day-care knee arthroscopy? Acta Anaesthesiol Scand 1994; 38: 156–60.
58. Ahmad S, Yilmaz M, Marcus RJ, et al. Impact of bispectral index monitoring on fast tracking of gynecologic patients undergoing laparoscopic surgery. Anesthesiology 2003; 98: 849–52.
59. Tramer M, Moore A, McQuay H. Propofol anaesthesia and postoperative nausea and vomiting: quantitative systematic review of randomized controlled studies. Br J Anaesth 1997; 78: 247–55.
60. Egger M, Zellweger-Zahner T, Schneider M, et al. Language bias in randomised controlled trials published in English and German. Lancet 1997; 350: 326–9.