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Controversies in Adult Outpatient Anesthesia

Steven L. Shafer, M.D.

Friday, November 22, 1996

This talk will consider several controversial issues in Adult Outpatient Anesthesia. Specifically, we will consider what drugs are best for outpatient anesthesia, what is the best system for evaluating outpatients prior to surgery, and are “healthy smokers” at increased risk during outpatient anesthesia.

1. What are the best anesthetic drugs for outpatient anesthesia?

This is a question that has been abundantly investigated through the support of the pharmaceutical industry. As each new anesthetic drug is introduced into the anesthetic practice, the pharmaceutical company generally sponsors research to demonstrate the advantages of the product. However, as White and Smith observed, “anesthesia practitioners, as well as pharmacy and therapeutic committees, are demanding proof that a new, more costly drug or medical device is superior to existing products in achieving its desired effect, is associated with fewer adverse effects, enhances efficiency, and reduces health care costs.”[i] The issue on costs is particularly acute. If a new drug results in patients awakening 1 minute faster in the operating room, is there any cost savings from this? As we consider the drugs available to the practitioner, we need to consider the overall cost benefits of new drugs in clinical practice.

One of the major changes in the past 10 years has been the introduction of propofol for induction of anesthesia. Thiopental has been the mainstay of intravenous induction agents for several decades. It would appear that patients receiving propofol for induction recover more quickly than those receiving thiopental. Gupta and colleagues compared propofol with thiopental for induction in 30 healthy, unpremedicated patients undergoing outpatient arthroscopic procedures of the knee.[ii] Using the perceptive accuracy test they demonstrated that subjects receiving propofol returned to baseline 60 minutes after the conclusion of surgery, while those receiving thiopental required 120 minutes to return to baseline. This is similar to the results reported by Kortilla and colleagues in volunteers. In a double-blind, crossover, volunteer study they examined recovery characteristics following 2.5 mg/kg of propofol followed by a brief infusion with 5.0 mg/kg of thiopental followed by a brief infusion.[iii] Subjects in the propofol group could stand by 33 min, while those receiving thiopental required 62 minutes to recover to the point of standing.

There are other advantages of propofol compared to thiopental in the recovery period. Propofol is known to posses antiemetic properties, and decreased nausea and vomiting may translate into faster recovery and reduced drug costs. However, propofol is clearly more expensive than thiopental. Is it worth the extra cost? Wagner and O’Hara considered this question recently.[iv] Using patient records they compared the cost of propofol vs thiopental anesthesia in 243 patients undergoing laparoscopic surgery. They calculated the costs of medications, operating room time, recovery room time, and ancillary costs. They concluded that “Despite the higher drug cost for propofol, the total mean cost was $273.00 less per patient for patients receiving propofol induction anesthesia.”

Propofol can also be used for maintenance of anesthesia. Siler and colleagues examined whether propofol anesthetics were associated with shorter recovery room stays than anesthesia maintained with other drugs.[v] They found that the use of propofol to maintain anesthesia was associated with less drowsiness (12% vs 31% for non-propofol anesthetics), less nausea and vomiting (3% vs 25% for non-propofol anesthetics)

In a direct comparison with isoflurane, Valanne compared 25 subjects receiving either a propofol infusion or isoflurane for maintenance of anesthesia. The cases were selected to provide an expected duration of 2-4 hours of anesthesia. All subjects were induced with propofol. Patients receiving propofol became oriented faster (11 min vs 17 min for isoflurane). At 60 min following the conclusion of anesthesia, all of the propofol patients could walk easily. In those patients maintained with isoflurane, 11 of 25 patients were unsteady when walking. The incidence of nausea and vomiting was 2 of 25 in the propofol group and 14 of 25 in the isoflurane group. Time to discharge was 80 min in the propofol group and 102 min in the isoflurane group. Studies such as this suggest considerable benefit to propofol for maintenance of anesthesia with propofol for outpatients.

These results are similar to, but not identical to, those reported by Ding and colleagues in comparing propofol maintenance with enflurane maintenance.[vi] They examined 61 female outpatients undergoing laparoscopic surgery. They found that propofol maintenance resulted in a slightly faster time to eye opening than enflurane maintenance. However, the use of propofol did not reduce the any of the recovery room times, including time to sitting, walking, or being “fit for discharge.” However, the incidence of nausea and vomiting was much less in the propofol group. The reduced incidence of nausea and vomiting was the biggest benefit observed with the use of propofol for maintenance. In a study of nearly identical design Fredman compared propofol with sevoflurane.[vii] They found that propofol anesthesia and sevoflurane anesthesia produced nearly identical recovery times. The only advantage of propofol was a reduced incidence of nausea and vomiting.

Rapp and colleagues compared propofol maintenance with desflurane maintenance.[viii] They examined 91 patients undergoing peripheral orthopedic surgery. They found that emergence times and recovery profiles were nearly identical between propofol and desflurane. The only clear difference was that patients induced and maintained with propofol had reduced nausea and vomiting in the recovery room when compared with desflurane.

Some studies have suggested that recovery from sevoflurane may be faster than recovery from propofol anesthesia. Wandel and colleagues compared two groups of 25 patients randomized to receive either propofol or sevoflurane for maintenance of anesthesia.[ix] They found that patients who received sevoflurane were extubated earlier than those receiving propofol (8 min vs 14 min). Recovery, as measured using Aldrete scores, was also faster in the group receiving sevoflurane.

Eriksson and colleagues compared sevoflurane with isoflurane in 50 women undergoing laparoscopic surgery.[x] Subjects in the sevoflurane group were able to follow orders faster than those in the isoflurane group (2.6 min vs 4.3 min). However, there was no change in the recovery room profile between the groups, in terms of time to walking, voiding, or discharge.

Nathanson and colleagues compared sevoflurane with desflurane for maintenance of anesthesia in 42 women outpatients.[xi] Intraoperatively sevoflurane was associated with lower heart rates than desflurane. Desflurane was associated with a more rapid awakening (4.8 vs 7.8 min after turning off the anesthetic) and a shorter time to extubation (5.1 vs 8.2 min). However, the all recovery parameters in the PACU, including time to discharge, were identical between the two groups.

Pain management in outpatients is also an important consideration. Intraoperative opioids are often administered to provide a stable anesthetic and to reduce postoperative pain. However, opioids are also associated with nausea and vomiting in the postoperative period. Several studies have examined alternatives to opioids for pain management. Ding and White compared ketorolac 60 mg, dezocine 6 mg, and fentanyl 100 (g in women undergoing outpatient laparoscopy.[xii] In the PACU they found that 61% of the patients in the fentanyl group had persistent pain, compared with 34% in the ketorolac group and 25% in the dezocine group. The dezocine group was associated with significantly more nausea and prolonged sedation than either the ketorolac or fentanyl groups. They concluded that ketorolac and fentanyl were both acceptable analgesics, but that dezocine was associated with increased complications.

Interestingly, another study from the same laboratory compared ketorolac and fentanyl in 109 patients. Patients were randomized to receive either fentanyl 50-100 (g, ketorolac 30-60 mg, or a combination of the two.[xiii] In this study, 75% of the subjects receiving ketorolac required intraoperative fentanyl, compared with 19% in the groups receiving fentanyl. While recovery times were similar for all three groups, the group receiving ketorolac had significantly more pain in the early postoperative period.

Higgins and colleagues compared ketorolac to ibuprofen and placebo in 50 women undergoing laparoscopic tubal ligation.[xiv] All patients received 2 (g/kg of fentanyl with the induction of anesthesia. In the recovery room 80% of the control patients required parenteral morphine in the control (placebo) group, compared with 73% in the ketorolac and ibuprofen groups, a difference that was not significant. There was no difference in the doses of morphine that were required. There was no difference in pain scores, recovery times, or the incidence of nausea and vomiting. These authors concluded that ketorolac and ibuprofen added little as postoperative analgesics.

The only clearly positive study I could find supporting the use of ketorolac in the outpatient area is that by Lysak and colleagues.[xv] Interestingly, even though this is an “anesthesia” study, it is published in the obstetrics and gynecology literature. These authors compared ketorolac 60 mg intramuscular injection, piroxicam 40 mg oral, and fentanyl 100 (g iv on induction of anesthesia. Subjects receiving ketorolac were discharged faster than those receiving fentanyl (96 vs 121 min) or piroxicam (96 vs 124 min). There was no difference in side effects between the groups.

In addition to new anesthetics and analgesics, there has been considerable progress over the last decade in developing new muscle relaxants. Two new relaxants, mivacurium and rocuronium, may offer advantages in the outpatient setting. Polar and colleagues compared mivacurium to succinylcholine in 60 healthy patients undergoing laparoscopy.[xvi] They found that micacurium 0.15 mg/kg provided good to excellent conditions for intubation in 2 to 3 minutes, and provided a duration of action of 20 to 25 minutes. However, they did not see any advantage of mivacurium over succinylcholine. In a subsequent study the research team compared succinylcholine 1 mg/kg, rocuronium 5-10 mg, and mivacurium 2-4 mg in 100 women undergoing laparoscopic surgery.[xvii] They found that after 90 seconds tracheal intubating conditions were significantly better in the succinylcholine and rocuronium groups than in the mivacurium group. Recovery was significantly faster in the succinylcholine and mivacurium groups than in the rocuronium patients. 16% of subjects receiving succinylcholine reported myalgia, compared with none in patients receiving rocuronium or mivacurium. The authors concluded that rocuronium may be useful in the outpatient setting, but that reversal will probably be needed. Mivacurium is an acceptable alternative, and may not require reversal, but should not be used if rapid intubation is indicated.

2. How should outpatients be evaluated prior to anesthesia?

There are a variety of mechanisms to evaluation patients prior to outpatient anesthesia. These are nicely reviewed by Apfelbaum in his recent ASA Refresher Course.[xviii] He summarizes the options as follows:

1. Facility (hospital or laboratory) Visit: In this approach, the patient comes to the hospital for a variety of laboratory tests and evaluations, which includes a visit with an anesthesiologist. However, the anesthesiologist must fit the visit in with the rest of the patient’s activities during the visit. While this approach is convenient for the patient, it reduces the anesthesiologist being one of several technicians the patient must interface with prior to surgery. As a result, the anesthesiologist is not provided with an opportunity to practice the type of perioperative medicine that is becoming an important part of our specialty.

2. Clinic Visit: In this approach, the Anesthesiology service runs a clinic to perform preoperative evaluations. The patient schedules an appointment with the clinic. The visit to the clinic provides an opportunity for the anesthesiologist to evaluate the medical condition of the patient, arrange necessary consulting evaluations if necessary, and schedule any necessary additional laboratory tests. This provides an excellent service to both the patient and the surgeon. It also fosters the ability of our specialty to provide expertise in perioperative medicine. This is the approach that we have implemented at both Stanford Hospital and at the Palo Alto VA Hospital with excellent results. This approach significantly reduces cancellations on the day of surgery because the patient’s medical condition has been thoroughly evaluated by an anesthesiologist prior to the day of surgery.

3. Telephone Interview: In this approach, the anesthesiologist takes a history during a phone call. The physical examination is deferred until the day of surgery. In this approach, the role of the anesthesiologist is again relegated to a technical support role, and the opportunity for a thorough evaluation of the patient is lost.

4. Morning of operation visit: In this setting, the patient is evaluated the morning of surgery. With healthy patients, this can be an efficient method of screening. However, it depends on the surgeons properly selecting appropriate patients to be seen the morning of surgery. Health problems may be identified immediately prior to surgery that require further evaluation before the patient can be safely anesthetized. Additionally, it does not afford the anesthesiologist the opportunity to discuss measures the patient might take prior to surgery to increase safety. For example, avoiding cigarettes for several days before surgery, careful attention to “NPO” instructions, and trimming or shaving of full beards are all instructions that patients might benefit from hearing a few days prior to surgery. When the preanesthetic visit occurs on the day of surgery, it must be understood by everyone that surgery will only proceed if the patient is medically ready for anesthesia and surgery.

3. Does smoking influence recovery from anesthesia?

The data for this comes from a complete analysis provided by Handlin and Baker[xix] who reviewed several prior studies. They found that the biggest predictor of the time in the recovery room was, as expected, the duration of anesthesia. The only other variable associated with recovery room time was a history of smoking. Specifically, only 23% of smokers were able to leave the recovery room in 1 hour, far less than the 38% of nonsmokers who were discharged within 1 hours. Of interest is that attempts to stratify the smokers into different degrees of cigarette exposure did not show any differences. The authors concluded: “any degree of smoking must now be viewed as having serious consequences in the immediate postoperative period and must be discouraged.” Thus, even patients who consider themselves “healthy smokers” are at risk of increased recovery time following anesthesia.

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[i] White PF; Smith I. Impact of newer drugs and techniques on the quality of ambulatory anesthesia. Journal of Clinical Anesthesia, 1993 Nov-Dec, 5(6 Suppl 1):3S-13S.

[ii] Gupta A; Larsen LE; Sjoberg F; Lindh ML; Lennmarken C. Thiopentone or propofol for induction of isoflurane-based anaesthesia for ambulatory surgery? Acta Anaesthesiologica Scandinavica, 1992 Oct, 36(7):670-4.

[iii] Korttila K; Nuotto EJ; Lichtor JL; Ostman PL; Apfelbaum J; Rupani G. Clinical recovery and psychomotor function after brief anesthesia with propofol or thiopental. Anesthesiology, 1992 May, 76(5):676-81.

[iv] Wagner BK; O'Hara DA. Cost analysis of propofol versus thiopental induction anesthesia in outpatient laparoscopic gynecologic surgery. Clinical Therapeutics, 1995 Jul-Aug, 17(4):770-6.

[v] Siler JN; Horrow JC; Rosenberg H. Propofol reduces prolonged outpatient PACU stay. An analysis according to surgical procedure. Anesthesiol Rev, 1994 Jul-Aug, 21(4):129-32.

[vi] Ding Y; Fredman B; White PF. Recovery following outpatient anesthesia: use of enflurane versus propofol. Journal of Clinical Anesthesia, 1993 Nov-Dec, 5(6):447-50.

[vii] Fredman B; Nathanson MH; Smith I; Wang J; Klein K; White PF. Sevoflurane for outpatient anesthesia: a comparison with propofol. Anesthesia and Analgesia, 1995 Oct, 81(4):823-8.

[viii] Rapp SE; Conahan TJ; Pavlin DJ; Levy WJ; Hautman B; Lecky J; Luke J; Nessly ML. Comparison of desflurane with propofol in outpatients undergoing peripheral orthopedic surgery. Anesthesia and Analgesia, 1992 Oct, 75(4):572-9.

[ix] Wandel C; Neff S; Bohrer H; Browne A; Motsch J; Martin E. Recovery characteristics following anaesthesia with sevoflurane or propofol in adults undergoing out-patient surgery. European Journal of Clinical Pharmacology, 1995, 48(3-4):185-8.

[x] Eriksson H; Haasio J; Korttila K. Recovery from sevoflurane and isoflurane anaesthesia after outpatient gynaecological laparoscopy. Acta Anaesthesiologica Scandinavica, 1995 Apr, 39(3):377-80.

[xi] Nathanson MH; Fredman B; Smith I; White PF. Sevoflurane versus desflurane for outpatient anesthesia: a comparison of maintenance and recovery profiles. Anesthesia and Analgesia, 1995 Dec, 81(6):1186-90.

[xii] Ding Y; White PF. Comparative effects of ketorolac, dezocine, and fentanyl as adjuvants during outpatient anesthesia [see comments]. Anesthesia and Analgesia, 1992 Oct, 75(4):566-71.

[xiii] Ding Y; Fredman B; White PF. Use of ketorolac and fentanyl during outpatient gynecologic surgery. Anesthesia and Analgesia, 1993 Aug, 77(2):205-10.

[xiv] Higgins MS; Givogre JL; Marco AP; Blumenthal PD; Furman WR. Recovery from outpatient laparoscopic tubal ligation is not improved by preoperative administration of ketorolac or ibuprofen. Anesthesia and Analgesia, 1994 Aug, 79(2):274-80.

[xv] Lysak SZ; Anderson PT; Carithers RA; DeVane GG; Smith ML; Bates GW. Postoperative effects of fentanyl, ketorolac, and piroxicam as analgesics for outpatient laparoscopic procedures. Obstetrics and Gynecology, 1994 Feb, 83(2):270-5.

[xvi] Poler SM; Watcha MF; White PF. Mivacurium as an alternative to succinylcholine during outpatient laparoscopy. Journal of Clinical Anesthesia, 1992 Mar-Apr, 4(2):127-33.

[xvii] Tang J; Joshi GP; White PF. Comparison of rocuronium and mivacurium to succinylcholine during outpatient laparoscopic surgery. Anesthesia and Analgesia, 1996 May, 82(5):994-8.

[xviii] Apfelbaum, JL. Current Controversies in Adult Outpatient Anesthesia. 1995 Annual Refresher Course Lectures. ASA, 1995.

[xix] Handlin DS; Baker T. The effects of smoking on postoperative recovery. American Journal of Medicine, 1992 Jul 15, 93(1A):32S-37S.

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