IS REGIONAL ANESTHESIA APPROPRIATE FOR AMBULATORY SURGERY?

Erwin Kresnoadi, M.D, M.Med.Sc

Department Of Anesthesiology and Reanimation

University of Mataram / West Nusa Tenggara General Hospital

==================================================================

There is continuing debate about whether Regional anaesthesia (RA) or General anaesthesia

(GA) is better for ambulatory surgery. The answer is not straightforward. To implement a successful

RA ambulatory program, it is essential to have a teamwork approach between anaesthetist, surgeon

and ambulatory nurses, conducive to the practice of RA. With this teamwork approach RA can be

very appropriate for ambulatory surgery.

RA whether used alone or in combination with GA offers significant advantages to the

patient. RA provides selective analgesia to the surgical site reducing systemic analgesic requirements

and minimising opioid related side effects such as dizziness and nausea and vomiting. As a

consequence the recovery process can be facilitated, enabling earlier ambulation and discharge home.

RA alone is not appropriate for all ambulatory surgery; therefore careful patient, procedure and

surgeon selection is of key importance.

Practical Implementation of Regional Anaesthetic techniques

To streamline RA there are specific strategies an ambulatory team may pursue. The block

should be performed in a dedicated block room or recovery room with monitoring and oxygen

facilities and adequate time allowed for block onset. Intravenous sedation techniques are useful at

block insertion so that amnesia and anxiolysis can be achieved, however prolonged effects of sedative

agents can potentially delay discharge. Patients can be discharged from ambulatory surgery with

padding and protection of the insensate limb, provided both written and verbal discharge instructions

are given.

Peripheral Nerve Blockade

Upper limb surgery is most suited to peripheral nerve blockade (PNB). For short procedures

(eg carpal tunnel release) intravenous regional anaesthesia provides excellent surgical conditions with

quick recovery of neurologic function. Longer upper extremity procedures (eg rotator cuff repair)

associated with significant postoperative pain is best performed using brachial plexus anaesthesia.

The site of surgery will dictate which approach the clinician should take to the brachial plexus.

Interscalene block, acting at the roots of the brachial plexus, gives a reliable block for shoulder

surgery and provides adequate pain control for early rehabilitation. Infraclavicular block and the more

peripheral axillary approach to the brachial plexus are suitable for elbow and hand surgery

1

respectively. Compared to the traditional paraesthesia technique, nerve stimulation using insulated

needles is now used widely for PNB.

Lower extremity blocks are often under-utilised in ambulatory surgery. Femoral nerve block

provides excellent analgesia for knee surgery and varicose vein stripping, significantly improving

patient satisfaction. Blockade of the sciatic and femoral nerves more distally at the popliteal level,

predominantly used for foot and ankle surgery, has a high success rate with good postoperative pain

relief for up to 24 hours. Ankle block is a simple, safe technique for mid and forefoot surgery.

Addition of adjuvants such as clonidine to long acting local anaesthetics (LA) will prolong

postoperative analgesia produced by PNB.

Whilst its use today has been confined to a clique of adventurous anaesthesiologists,

paravertebral blocks are likely to become the technique of choice for many procedures that are

currently performed under GA. It provides excellent prolonged analgesia (24 hours) following breast

surgery, inguinal, ventral, and umbilical hernia repair. Good anatomical knowledge and appropriate

technique will result in high success rates and minimal complications.1 Neuraxial Blockade

Epidural anaesthesia is time consuming to perform, and is slower in onset than spinal anaesthesia.

However it may be appropriate when surgical procedures have an unpredictable time course with its

flexibility of additional LA dosing through a catheter (eg cruciate ligament repair or bilateral varicose

vein surgery).

Spinal anaesthesia with its high reliability and fast onset of action is a simpler option to

epidural anaesthesia. The risk of spinal headache has been minimised (1%) with the use of fine gauge,

pencil-point needles. Using short acting LA drugs with lipophilic opioid (fentanyl), the frequency of

urinary retention is acceptably low. Fentanyl appears to increase duration and quality of spinal block

without increasing discharge time.2 There is a balance between rapid offset of effect with small LA

doses and higher doses of LA which guarantee adequate block height but may result in unacceptable

block duration and side effects such a urinary retention. Lignocaine has the optimal onset and duration

for ambulatory surgery but concern over transient neurological symptoms (pain or sensory

abnormalities in the lower back, buttocks or lower extremities) in up to 20% patients, limit its use.

Low dose bupivacaine (5 –10 mg) with 10-25 mcg fentanyl provides excellent anaesthesia with

acceptable discharge times following knee arthroscopy with minimal risk of transient neurologic

syndrome. More recently there have been significant advances in the practice of selective spinal

anaesthesia where the distribution of spinal block is restricted to the operative side. Potential benefits

include fewer cardiovascular side effects, less urinary retention, good patient acceptance and earlier

patient discharge compared to bilateral distribution of spinal anaesthesia; this makes selective spinal

techniques suitable to ambulatory surgery.3

Mulroy has recently questioned the practice of voiding before discharge in spinal patients

undergoing ambulatory surgery. In a study of 201 patients Mulroy concluded that in healthy patients

of less than 70 years of age with no history of voiding problems who are not undergoing surgery in

2

the perianal or perineal region, or hernia repair, may be discharged safely 2 hours after 6 mg

intrathecal bupivacaine even if they have not voided.4 However, further large studies should be

performed before these guidelines should be adopted in common ambulatory practice.

Post-operative Analgesia.

Prior to a central neuraxial block wearing off, alternative analgesic options should be

introduced such as wound infiltration or PNB to optimise patient’s pain relief. Multimodal analgesic

regimes should be commenced at the time of surgery combining LA with non-steroidal anti-

inflammatory drugs and simple oral analgesics. A documented pain management plan will assist the

patient manage rebound pain at home when LA wears off. More recently the use of continuous

infusion catheters has enabled more painful procedures such as major orthopaedic, plastic or vascular

surgery to be performed on a day basis.5 Catheters can be placed either perineurally or into the wound.

Portable disposable non-electronic pumps preloaded with low concentration local anaesthetic (eg

ropivacaine 0.2%) and preset hourly infusion rates allows practical patient administration at home for

procedures such as major shoulder or knee surgery. Combining a basal infusion rate of LA with a

patient controlled bolus may provide best pain relief with good patient satisfaction. 6 Patients can

remove the catheters themselves however a home nursing service is desirable.

Further clinical studies are required to identify the most cost-effective anaesthetic technique

for ambulatory surgery. PNB in particular offers significant advantages over central neuraxial

blockade, and should be a key area for anaesthetists’ further education. There is also great enthusiasm

for catheter techniques, but limiting factors are appropriate training, and technical difficulties

associated with catheters and pump technology.

References

1. Klein SM, Bergh A, Steele SM et al. Thoracic paravertebral block for breast surgery. Anesth Analg 2000; 90: 1402-5.2. Ben-David B, Maryanovsky M, Gurevitch A et al. a comparison of mini-dose lidocaine-fentanyl and conventional-dose lidocaine

spinal anaesthesia. Anesth Analg 2000; 91:865-8703. Fanelli G, Borghi B, Casati A, Bertini L, Montebugnoli M, Torri G. Unilateral bupivacaine spinal anesthesia for outpatient knee

arthroscopy. Can J Anesth 2000;47: 746-751. 4. Mulroy MF, Salinas FV, Larkin KL, Polissar NL. Ambulatory surgery patients may be discharged before voiding after short-

acting spinal and epidural anesthesia. Anesthesiology 2002;Aug;97(2):315-319.5. Rawal N, Axelsson K, Hylander J, etal. Postoperative patient-controlled local anaesthetic administration at home. Anesth Analg

1998;86:86-9.6. Borgeat A, Kalberer F, Jacob H et al. Patient-controlled interscalene analgesia with ropivacaine 0.2% versus bupivacaine 0.15%

after major open shoulder surgery: the effects on hand motor function. Anesth Analg 2001; 92:218-223.

3

MONITORED ANESTHESIA CARE AND REGIONAL ANESTHESIA FOR

AMBULATORY SURGERY

Erwin Kresnoadi, M.D, M.Med.Sc

Department Of Anesthesiology and Reanimation

University of Mataram / West Nusa Tenggara General Hospital

==================================================================Use of local anesthetic infiltration and peripheral nerve blocks in combination with

intravenous analgesic and sedative drugs is gaining popularity in the ambulatory setting. It has been

estimated that over 50% of all outpatient (day-surgery) procedures could be performed utilizing these

techniques. When patients are undergoing procedures under local anesthesia with sedation in the

operating room (OR), the old terminology used to describe the care of these patients was “conscious

sedation”.1 As the term implies, conscious sedation was a minimally-depressed level of consciousness

that retained the patient’s ability to maintain an airway independently and continuously, and to

respond appropriately to physical stimulation and verbal commands. The ASA avoids this term in

their Practice Guidelines of Sedation and Analgesia by Non-anesthesiologists because it is imprecise. 2

The preferred terminology is therefore monitored anesthesia care (MAC).

Monitored anesthesia care

MAC is the term used when an anesthesiologist monitors a patient receiving local anesthesia

alone or administers anesthetic drugs to patients undergoing diagnostic or therapeutic procedures with

or without local anesthesia.3 The ASA defines MAC as instances in which an anesthesiologist has

been called on to provide specific anesthesia services to a particular patient undergoing a planned

procedure, in connection with which a patient receives local anesthesia or, in some cases, no

anesthesia at all. In such a case, the anesthesiologist is providing specific services to the patient, is in

control of his or her vital signs, and is available to administer anesthetics or provide other medical

care as appropriate.4 The standard of care of patients receiving monitored anesthesia care should be

the same as for patients undergoing general or regional anesthesia and should include a complete

preoperative assessment, intraoperative monitoring, and postoperative recovery. Vigilant monitoring

is required because patients may rapidly progress from a “light” level of sedation to “deep” sedation

(or unconsciousness), and thus may be at risk for airway obstruction, oxygen desaturation, and even

aspiration.

Anesthetic drugs are commonly administered during procedures under MAC to produce

analgesia, sedation, and anxiolysis, while providing for a rapid recovery without side effects.

Systemic analgesics are used to reduce discomfort associated with injection of local anesthetics and

prolonged immobilization, as well as pain which is not amendable to local anesthetics (e.g.,

endoscopy).5 Sedative drugs are used to make procedures more tolerable for patients by reducing

4

anxiety and by providing a degree of intraoperative amnesia and allowing to rest. During longer

surgical procedures, patients may become restless, bored, or uncomfortable when forced to remain

immobile, therefore sedative-hypnotic drugs may prove beneficial because they allow patients to rest.6

Patients’ anxiety can be reduced by using benzodiazepines, as well as by good preoperative

communication, keeping the patient warm and covered, and allowing the patient to listen to music

during the procedure.7

Many different sedative-hypnotic drugs have been used during MAC (including barbiturates,

benzodiazepines, ketamine, propofol and alpha-2 agonists). In addition, a wide variety of delivery

systems such as intermittent boluses, variable-rate infusions, target-controlled infusions, as well as

patient-controlled analgesia and/or sedation have been utilized during these procedures. 8 The most

commonly used sedative drugs are midazolam (1-2 mg) and propofol (0.5-1 mg/kg followed by

infusion at 25-100 µg/kg/min). Methohexital has also been used successfully during MAC by

intermittent boluses (10–20 mg) or as a variable-rate infusion (0.1–0.2% solution). 9 Although residual

sedation appears to be greater with methohexital than with propofol, one study found no statistical

difference in the recovery times when comparing infusions of methohexital (40 µg/kg/min) and

propofol (50 µg/kg/min) during a MAC technique. However, there was a higher incidence of pain on

injection in the propofol infusion group.10-12 Therefore, methohexital may be a cost-effective

alternative to propofol for sedation during MAC. Careful titration of the IV anesthetic is essential to

achieve the desired level of sedation and to ensure prompt recovery.3

In women undergoing laparoscopic tubal sterilization with a MAC technique the anesthetic

drug costs were significantly reduced compared to general anesthesia ($21 vs $46, respectively). The

MAC technique was also associated with less time in the OR (304 vs 341 min), a higher degree

of “awakeness” on the evening of the day of surgery (4.31.4 vs 3.61.4), as well as decreased

postoperative pain (33% vs 80%) and sore throats (3% vs 70%), contributing to a significant

reduction in perioperative costs.13 Patel et al14 reported that the use of MAC sedation resulted in a 6- to

7-minute decrease in the OR exit time compared to general anesthesia with desflurane, contributing to

enhanced turnover of cases. This is an important consideration in today’s practice environment with

the heavy emphasis on “fast-tracking” processes.

Avramov et al15 described the combined use of alfentanil (0.3–0.4 µg/kg/min) and propofol

(25, 50, or 75 µg/kg/min) infusions for MAC. Concomitant use of propofol significantly reduced the

opioid dose requirement (30–50%) and the incidence of postoperative nausea and vomiting (0–17%

vs 33%) when compared with alfentanil infusion alone. An infusion of remifentanil, 0.05 to 0.15

µg/kg/min, can provide adequate sedation and analgesia during minor surgical procedures performed

with the patient under local anesthesia when administered in combination with midazolam, 2 to 4 mg.

Sá Rêgo et al16 compared the use of intermittent remifentanil boluses (25 µg) vs a continuous

variable-rate infusion (0.025–0.15 µg/kg/min) when administered to patients undergoing ESWL under

a MAC technique involving midazolam (2 mg) and propofol (25–50 µg/kg/min). Patients comfort was

5

higher during the procedure when remifentanil was administered by a variable-rate infusion.

However, these patients also experienced a higher incidence of desaturation (30% vs 0%) compared

with those receiving small intermittent boluses of remifentanil. In a direct comparison of remifentanil

and propofol administered by continuous infusion after premedication with midazolam, there was a

decreased level of sedation and a greater degree of respiratory depression with remifentanil (versus

propofol) administration. Therefore, remifentanil infusions must be carefully titrated to avoid

excessive respiratory depression.17 The use of remifentanil in combination with local anesthetics

obviates the disadvantages of the minimal residual analgesia when remifentanil is used during painful

procedures.

Given the increased risk of ventilatory depression when opioid analgesics are combined with

sedative-hypnotics, a variety of non-opioid analgesics have been evaluated during MAC. Ketorolac, a

potent, parenterally-active NSAID has been used both as a sole supplement and as an adjunct to

propofol sedation during local anesthesia. Use of ketorolac is associated with a lower incidence of

pruritus, nausea, and vomiting than fentanyl. However, when used with propofol sedation, ketorolac-

treated patients required higher intraoperative doses of propofol and more supplemental opioid

analgesia compared with the use of fentanyl. Low-dose ketamine (0.25–0.75 mg/kg) combined with

either midazolam or propofol has also been administered before injection of local anesthetics in

outpatients undergoing cosmetic surgical procedures.18 Ketamine has the advantage over opioid

analgesics of producing less ventilatory depression and PONV while providing better intraoperative

analgesia than the NSAIDs. Both midazolam and propofol can attenuate.

Subanesthetic concentrations of inhaled anesthetics (e.g., N2O, 30–50% in oxygen or

sevoflurane 0.3-0.6%) can also be used to supplement local anesthesia.19 The primary concerns relate

to the ease which the patient can drift into an unconscious state, as well as operating room pollution.

The α2-agonists reduce central sympathetic outflow and have been shown to produce

anxiolysis and sedation.20 Kumar et al21 demonstrated that oral clonidine (300 µg) provided effective

anxiolysis for elderly patients undergoing ophthalmic surgery under local anesthesia and also

decreased the incidence of intraoperative hypertension and tachycardia. Dexmedetomidine, a more

selective and potent α2-agonist, significantly decreased anxiety levels and reduced the requirements

for supplemental analgesic medications when given before IV regional anesthesia for hand surgery.22

When comparing dexmedetomidine with midazolam for sedation, Aho et al23 described a faster

recovery from sedation when dexmedetomidine was followed by reversal with the specific α2-

antagonist atipamezole. However, the administration of dexmedetomidine has been associated with

bradycardia, which may limit its usefulness during MAC.22,24

Regional anesthesia

Regional anesthesia can offer many advantages for the ambulatory patient population. In

addition to limiting the anesthetized area to the surgical site, common side effects of general

6

anesthesia (e.g., nausea, vomiting, dizziness, lethargy) can be avoided.25 Furthermore, the need for

postanesthesia nursing care is decreased if effective analgesia is provided in the early postoperative

period.26,27 It has been suggested that regional anesthesia is cost- in the outpatient setting because of

the lower incidence of side effects and improved recovery compared with general anesthesia.28 Proper

patient selection along with the skill and enthusiasm of the surgical and anesthesia teams will allow an

even wider variety of procedures to be performed using regional anesthetic techniques in the future.

For short superficial surgical procedures (<60 min) limited to a single extremity, the

intravenous regional (Bier) block with lidocaine, 0.5% , is a simple and reliable technique. This

procedure, which can be used for either upper or lower extremity surgery, uses a double tourniquet to

decrease tourniquet pain. Intravenous regional anesthesia has been reported to be the most cost-

effective technique for outpatient hand surgery.29

If more profound and prolonged anesthesia of the upper extremity and shoulder is required, a

regional block of the brachial plexus can be used (e.g., axillary, supraclavicular or interscalene

block).30 Peripheral nerve blocks are also useful for surgery on the leg. The “three-in-one block”

(femoral, obturator, and lateral femoral cutaneous nerves) using a perivascular technique is useful for

outpatient knee arthroscopy and anterior cruciate ligament repairs, providing excellent postoperative

analgesia with a high degree of patient acceptance. Ankle blocks are also simple and effective

techniques for surgery on the foot. Popliteal sciatic nerve blocks have been shown to provide

excellent postoperative analgesia after foot and ankle surgery.31

In pediatric patients, peripheral nerve blocks can be performed immediately after induction of

general anesthesia to reduce the anesthetic requirement and provide postoperative analgesia.32

Historically, caudal anesthesia has been the most popular technique to reduce postoperative pain in

children undergoing lower abdominal, perineal, and lower extremity procedures. Other popular

regional anesthetic techniques include blockade of the ilioinguinal and iliohypogastric nerves to

minimize post-herniorrhaphy pain and the use of dorsal penial nerve block and subcutaneous ring

block postcircumcision pain.33 Interestingly, simple wound infiltration (or instillation) with local

anesthetics may be as effective as a caudal or ilioinguinal nerve block in reducing pain after inguinal

hernia repair.34 Studies also suggest that systemic ketorolac (1 mg/kg) is as efficacious as caudal

blockade, with a lower incidence of side effects.35 Similarly, topical lidocaine ointment is an effective

alternative to both a nerve block and opioid analgesics for postcircumcision pain.

Summary

MAC is the anesthetic technique of choice for providing cost-effective anesthetic care in the

ambulatory setting. Peripheral nerve blocks as part of a MAC sedation technique can further enhance

the efficacy of this technique. The most important factors in achieving the desired clinical outcome

are effective local analgesia and the careful titration of systemic sedative and analgesic medications.

7

References

1. Smith I, White PF: Monitored anesthesia care: How much sedation, how much analgesia? J Clin Anesth 8:76S, 1996.

2. Cruise CJ, Chung F, Yogendran S et al: Music increases satisfaction in elderly outpatients undergoing cataract surgery. Can J Anaesth 44:43, 1997.

3. Newson C, Joshi GP, Victory R et al: Comparison of propofol administration techniques for sedation during monitored anesthesia care. Anesth Analg 81:486, 1995.

4. American Society of Anesthesiologists: Position on Monitored Anesthesia Care. Directory of Members. Park Ridge, Illinois, American Society of Anesthesiologists, 1997, p 413.

5. Ghouri AF, Taylor E, White PF: Patient-controlled drug administration during local anesthesia: a comparison of midazolam, propofol and alfentanil. J Clin Anesth 4: 476-9, 1992.

6. White PF, Negus JB: Sedative infusions during local and regional anesthesia: A comparison of midazolam and propofol. J Clin Anesth 3:32, 1991.

7. Pratila MG, Fischer ME, Alagesan R et al: Propofol vs midazolam for monitored sedation: A comparison of intraoperative and recovery parameters. J Clin Anesth 5:268, 1993.

8. Taylor E, Ghouri AF, White PF: Midazolam in combination with propofol for sedation during local anesthesia. J Clin Anesth 4:213, 1992.

9. Sá Rêgo MM, Inagaki Y, White PF: The cost-effectiveness of methohexital versus propofol for sedation during monitored anesthesia care. Anesth Analg 88: 723-8, 1999.

10. Cohen MM, Duncan PG, DeBoer DP et al: The postoperative interview: Assessing risk factors for nausea and vomiting. Anesth Analg 78:7, 1994.

11. Honkavaara P, Lehtinen AM, Hovorka J et al: Nausea and vomiting after gynaecological laparoscopy depends upon the phase of the menstrual cycle. Can J Anaesth 38:876, 1991.

12. Beattie WS, Lindblad T, Buckley DN et al: The incidence of postoperative nausea and vomiting in women undergoing laparoscopy is influenced by the day of menstrual cycle. Can J Anaesth 38:298, 1991.

13. Bordahl PE, Raeder JC, Nordentoft J et al: Laparoscopic sterilization under local or general anesthesia? A randomized study. Obstet Gynecol 81:137, 1993.

14. Smith CE, Pinchak AC et al: Desflurane is not associated with faster operating room exit times in outpatients. J Clin Anesth 8:130, 1996.

15. Avramov MN, White PF. Use of alfentanil and propofol for outpatient monitored anesthesia care: determining the optimal dosing regimen. Anesth Analg 85:566, 1997.

16. Sa Rego MM, Watcha MF, White PF: The changing role of monitored anesthesia care in the ambulatory setting. Anesth Analg 85:1020, 1997.

17. Waters RM: The downtown anesthesia clinic. Am J Surg 33:71, 1919.

18. Korttila K, Ostman P, Faure E et al: Randomized comparison of recovery after propofol-nitrous oxide vs thiopentone-isoflurane-nitrous oxide anaesthesia in patients undergoing ambulatory surgery. Acta Anaesthesiol Scand 34:400, 1990.

19. Gold BS, Kitz DS, Lecky JH et al: Unanticipated admission to the hospital following ambulatory surgery. JAMA 262:3008, 1989.

20. Issioui T, Klein KW, White PF, et al. Cost-efficacy of rofecoxib vs acetaminophen for preventing pain after ambulatory surgery. Anesthesiology 97: 931, 2002.

21. Kumar A, Bose S, Bhattacharya A et al: Oral clonidine premedication for elderly patients undergoing intraocular surgery. Acta Anaesthesiol Scand 36:159, 1992.

22. McKenzie R, Uy NT, Riley TJ et al: Droperidol/ondansetron combination controls nausea and vomiting after tubal banding. Anesth Analg 83:1218, 1996.

23. Doze VA, Shafer A, White PF: Nausea and vomiting after outpatient anesthesia: Effectiveness of droperidol alone and in combination with metoclopramide. Anesth Analg 66:S41, 1987.

24. Tang J, Watcha MF, White PF: A comparison of costs and efficacy of ondansetron and droperidol as prophylactic antiemetic therapy for elective outpatient gynecologic procedures. Anesth Analg 83:304, 1996.

25. Philip BK: Regional anaesthesia for ambulatory surgery. Can J Anaesth 39:R3, 1992.

26. Mingus ML: Recovery advantages of regional anesthesia compared with general anesthesia: Adult patients. J Clin Anesth 7:628, 1995.

27. Bridenbaugh LD: Regional anaesthesia for outpatient surgery: A summary of 12 years’ experience. Can Anaesth Soc J 30:548, 1983.

28. Greenberg CP: Practical, cost-effective regional anesthesia for ambulatory surgery. J Clin Anesth 7:614, 1995.

29. Chan VW, Peng PW, Kaszas Z, et al. A comparative study of general anesthesia, intravenous regional anesthesia and axillary block for outpatient hand surgery: Clinical outcome and cost analysis. Anesth Analg 93:1181, 2001.

30. D’Alessio JG, Rosenblum M, Shea KP et al: A retrospective comparison of interscalene block and general anesthesia for ambulatory surgery shoulder arthroscopy. Reg Anesth 20:62, 1995.

31. Singelyn FJ, Aye F, Gouverneur JM: Continuous popliteal sciatic nerve block: An original technique to provide postoperative analgesia after foot surgery. Anesth Analg 84:383, 1997.

32. Pflug AE, Aasheim GM, Foster C: Sequence of return of neurological function and criteria for safe ambulation following subarachnoid block (spinal anaesthetic). Can Anaesth Soc J 25:133, 1978.

33. Vater M, Wandless J: Caudal or dorsal nerve block? A comparison of two local anaesthetic techniques for postoperative analgesia following day case circumcision. Acta Anaesthesiol Scand 29:175, 1985.

34. Reid MF, Harris R, Phillips PD et al: Day-case herniotomy in children: A comparison of ilio-inguinal nerve block and wound infiltration for postoperative analgesia. Anaesthesia 42:658, 1987.

35. Splinter WM, Reid CW, Roberts DJ, et al: Reducing pain after inguinal hernia repair in children: caudal anesthesia versus ketorolac tromethamine. Anesthesiology 87: 542, 1997.

8

AMBULATORY ANESTHESIA & SURGERY

Erwin Kresnoadi, M.D, M.Med.ScDepartment Of Anesthesiology and Reanimation

University of Mataram / West Nusa Tenggara General Hospital==================================================================Introduction

Ambulatory surgery accounts for over 60% of all elective operative procedures performed in

the United States. With the recent growth in major laparoscopic and office-based surgery, this

percentage may increase to 70% in the future. When surgery is performed outside the conventional

hospital environment, it can offer a number of advantages for patients, healthcare providers, third-

party payers, and even hospitals.1 Patients benefit from day surgery because it minimizes costs,

decreases separation from their home and family environment, reduces surgery waiting times,

decreases their likelihood of contracting hospital-acquired infections, and appears to reduce

postoperative complications. Compared to traditional hospital admissions, there is less pre- and

postoperative lab testing and also a reduced demand for postoperative pain medication following

ambulatory surgery. Unlike inpatient surgery, ambulatory surgery does not depend upon the

availability of a hospital bed and may permit the patient greater flexibility in selecting the time of

their elective operation. Furthermore, there is greater efficiency in the utilization of the operating and

recovery rooms in the ambulatory setting, contributing to a decrease in the overall patient charges

compared to similar hospital based care.

Comparison of general, spinal and local anesthesia

The optimal anesthetic technique in the ambulatory setting would provide for excellent

operating conditions, a rapid recovery, no postoperative side effects, and a high degree of patient

satisfaction. In addition to increasing the quality and decreasing the costs of the anesthetic services,

the ideal anesthetic technique would also improve operating room (OR) efficiency and provide for an

early discharge home without side effects. Local anesthesia with intravenous (IV) sedation (so-called

monitored anesthesia care [MAC]), spinal anesthesia, and general anesthesia are all commonly used

anesthetic techniques for ambulatory surgery. However, opinions differ as to the “best” anesthetic

technique for these surgical procedures.2-15 Rather than simply generalizing as to the best anesthetic

technique for ambulatory surgery, it is necessary to individually analyze each surgical procedure. For

example, in an Editorial in Anesthesia & Analgesia16, Kehlet and White discussed the optimal anesthetic

technique for inguinal hernia repair.

In the current cost-conscious environment, it is important to also examine the impact of

anesthetic techniques on OR turnover times, as well as the recovery process after ambulatory surgery

9

because prolonged recovery times and reduced efficiency and productivity contribute to increased cost of

surgical care.10 In addition, patient satisfaction with their perioperative experience and quality of recovery

is improved when the anesthetic technique chosen for the procedure is associated with a low incidence of

postoperative side effects [e.g., pain, dizziness, headaches, postoperative nausea and vomiting

(PONV)].10,11 For example, routine use of prophylactic antiemetic drugs during general anesthesia has

been found to increase patient satisfaction in “at risk” surgical populations.17 Furthermore, the use of local

anesthetic infiltration and peripheral nerve blocks decreases postoperative pain after ambulatory surgery

procedures irrespective of the anesthetic technique.4,18,19

The time required to achieve a state of home-readiness (“fitness” for discharge home) is

influenced by a wide variety of surgical and anesthetic factors.20,21 However the major contributors to

delays in discharge after ambulatory surgery are nausea, vomiting, dizziness, pain and prolonged

sympathetic and/or motor blockade. Although the incidence of PONV can be decreased by the use of

prophylactic antiemetic drugs,17 it remains a common side effect after general anesthesia and prolongs

discharge after ambulatory surgery.10,11 The primary factors delaying discharge after spinal anesthesia

are recovery from the residual motor blockade and sympatholytic effects of the subarachnoid block,

contributing to delayed ambulation and inability to void. These side effects can be minimized by the

use of so-called mini-dose lidocaine fentanyl spinal anesthetic techniques.13,15 Other common concerns

with spinal anesthesia include back pain, post-dural puncture headache and transient radicular

irritation with lidocaine.22,23 Although MAC is associated with the lowest incidence of postoperative

side effects,10,11 the possibility of transient nerve palsy is a concern when peripheral nerve block

techniques are used.25,26

The cost savings with the use of newer general anesthetic techniques are lost if institutional

practices mandate minimum lengths of stay in the Phase 1 unit [Postanesthesia care unit (PACU)] and

do not permit fast-tracking of patients who emerge rapidly from anesthetic directly to the Phase 2

[Day-surgery (“step-down”)] unit. Claims of reduced total costs with earlier discharge are commonly

based on the assumption that there is a linear relationship between the costs of a service and the time

spent providing it. However, since personnel costs are semi-fixed rather than variable, an additional

15-30 minute stay in the PACU may not be associated with increased costs to the institution unless

the facility is working at or near its capacity.27 In that situation, a longer stay is potentially associated

with a “bottleneck” in the flow of patients through the OR suites and recovery areas, requiring

overtime payments to the nurses and/or the hiring of additional perioperative personnel. There appears

to be a much closer relationship between lower costs and bypassing of the PACU (“fast-tracking”), as

the major factor in recovery care costs relates to the peak number of patients admitted to the PACU

unit at any time.27 Fast-tracking can lead to the use of fewer nurses and a mix of less highly trained,

lower wage nursing aides and fully-qualified recovery room nurses, and reduces “overtime” personnel

costs for busy ambulatory surgery units. Shorter anesthesia times, the ability to bypass the PACU

10

(Phase 1), and a decreased length of stay in the day-surgery (Phase 2) unit will reduce total

institutional costs.28 Studies have demonstrated that “fast-tracking” ambulatory surgery patients

decrease the times to actual discharge.29,30

The combination of low costs and high patient satisfaction suggests that the highest quality

(cost/outcome) anesthetic may be achievable with a MAC technique assuming that the surgical

procedure is amendable to this anesthetic approach (e.g., superficial surgical and endoscopic

procedures. Unfortunately, many pharmacoeconomic studies have limited cost considerations to only

the acquisition costs of the drugs and supplies rather than the total (direct + indirect) expenses

associated with a given anesthetic technique. The total cost should include both the acquisition costs

of drugs and the labor required for managing side effects (e.g., PONV, pain, drowsiness, bladder

dysfunction). Since personnel costs constitute a major proportion of expenses in the OR and recovery

areas, anesthetic techniques which require more time in the various phases of the perioperative

process will not surprisingly be more expensive.10,11

The availability of improved sedation and analgesia techniques to complement local

anesthetic infiltration has increased the popularity of performing surgery utilizing MAC techniques.31

The high patient satisfaction with local anesthesia/sedation is also related to effective control of

postoperative pain and the absence of side effects associated with the other commonly used general

and spinal anesthetic techniques. The success of MAC techniques is dependent not only on the

anesthesiologist, but also upon the skills of the surgeon in providing effective infiltration analgesia

and gentle handling of the tissues during the intraoperative period. Local anesthesia without any

monitoring or intravenous adjuvants (so-called “unmonitored” local anesthesia), has been successfully

used in situations where local anesthesia is able to provide excellent analgesia and patients do not

object to being awake and aware of events in the operating room.32 The importance of good surgical

skills is critically important because inadequate intraoperative control of pain can lead to prolonged

surgery times and patient dissatisfaction with their surgical experience. In a prospective, randomized

comparison of local infiltration with spinal and general anesthesia (33), surgeons in Sweden suggested

the technical difficulties and patient pain were “more intense” during surgery under local anesthesia.

This finding is consistent with an earlier report by Fairclough et al .34 However, with these surgical

provisions, it is widely accepted that superficial surgical procedures can be performed as safely and

effectively under local anesthesia as under any other form of anesthesia. In fact, the researchers in

Sweden concluded that “for most patients, local anesthesia can be recommended as the standard

procedure for outpatient knee arthroscopy”.33

While most studies have suggested that local anesthesia (e.g., local infiltration and/or

peripheral nerve blocks) are not only well-accepted by patients and surgeons for superficial outpatient

procedures (e.g., breast surgery, knee arthroscopy, anorectal surgery, and inguinal herniorrhaphy) but

is also more cost-effective than either spinal or general anesthesia,10,11,35 some studies have suggested

that spinal anesthesia is more cost- effective than general anesthesia.5,7 These and other studies have

11

suggested that the use of smaller dosages of lidocaine (15-30 mg) or bupivacaine (3-6 mg) combined

with a potent opioid (e.g., fentanyl, 12.5-25 g, or sufentanil, 5-10 µg) contributes to a faster recovery

of both motor and bladder function than conventional doses of the local anesthetic alone. Earlier

discharge after spinal anesthesia using the so-called mini-dose techniques will clearly improve its

cost-effectiveness in the ambulatory setting. Unfortunately, side effects such as pruritis and nausea are

increased even when small doses of fentanyl (or sufentanil) are administered into the subarachnoid

space.15

Even though central neuroaxial blocks can be made more cost-effective by using smaller

doses of short-acting local anesthetics combined with potent opioid analgesics, use of MAC

techniques for superficial (non-cavitary) ambulatory surgery procedures will result in the shortest

times to home readiness, lowest pain scores at discharge, and smallest incremental costs when

compared to both spinal and general anesthesia.10,11 Therefore, in situations where fast-tracking is

permitted, the use of MAC techniques would appear to offer significant advantages over both central

neuroaxis blocks (i.e., spinal/epidural) and general anesthetic techniques.

The availability of more rapid and shorter-acting intravenous and inhaled anesthetics,

analgesics and adjunctive drugs, as well as improved cerebral monitoring capabilities, has facilitated

the recovery process after general anesthesia. For example, studies involving the use of “light”

general anesthetic techniques with a laryngeal mask airway device and local analgesia have

demonstrated that outpatients undergoing superficial surgical procedures (e.g., hernia repair, breast

surgery) are able to ambulate within 30 min and can be discharged home in less than 60 min after

completion of their operation (36-38). When tracheal intubation is required [e.g., laparoscopic

procedures, risk factors for aspiration (e.g., diabetics, morbidly obese, esophageal dysfunction)], use

of minimal, effective doses of newer short-acting opioid analgesics (e.g., remifentanil) and

sympatholytic (e.g., esmolol) drugs can facilitate the early recovery process and allow patients to

achieve earlier discharge times after ambulatory surgery.39-42 The use of the more costly drugs can be

economically justified if improvements in recovery and work patterns can be demonstrated.43

However, anesthetic practices have advanced to the point where cost savings from variations in drug

use are only apparent when system-wide improvements are made in the efficacy of resource

utilization (including personnel, space, time, consumables and capital investments).44

Fast-tracking concepts

Ambulatory anesthesia is administered with the dual goals of rapidly and safely establishing

satisfactory conditions for the performance of therapeutic or diagnostic procedures while ensuring a

rapid, predictable recovery with minimal postoperative sequelae. If the careful titration of short-acting

drugs permits a safe transfer of patients directly from the operating room suite to the less labor-

intensive recovery area where the patient can be discharged home within one hour after surgery,

significant cost savings to the institution can be achieved.44 Bypassing the Phase I recovery (i.e.,

12

PACU) has been termed “fast-tracking” after ambulatory surgery.45 In addition, fast-tracking can also

be accomplished directly from the PACU by creating a specialized area where recovery procedures

are organized along the lines of a step-down unit.46 The criteria used to determine fast-track eligibility

has been made even more stringent than the standard PACU discharge criteria in order to reduce the

need for interventions in areas with less nursing personnel. The use of anesthetic techniques

associated with a more rapid recovery will result in fewer patients remaining deeply sedated in the

early postoperative period30,48, decrease the risk for airway obstruction and cardiorespiratory

instability, and reduce the number of nursing interventions.49 By reducing the need for “intensive”

nursing care in the early postoperative period using anesthetic techniques associated with a faster

emergence from anesthesia, a well-organized fast tracking program can permit an institution to use

fewer nurses in the recovery areas and leads to significant cost savings.50 The fast-track concept is

gaining wider acceptance throughout the world.51 Even elderly outpatients can be fast-tracked after

general anesthesia if short-acting drugs are utilized.49

Improved titration of anesthetic drugs using EEG-based cerebral monitors (e.g., bispectral

index [BIS], physical state index [PSI], auditory-evoked potential [AEP], and entropy) can lead to a

faster emergence from anesthesia and can be useful in predicting fast-track eligibility .54 Although the

early studies involving propofol and the newer volatile anesthetics sevoflurane and desflurane 53,

suggested that the anesthetic-sparing effect could facilitate a faster emergence from anesthesia, these

studies failed to demonstrate a decrease in the times to discharge home because standard recovery

practices were used. However, if outpatients are allowed to recover via a fast-track pathway, use of

cerebral monitoring can actually reduce discharge times.55

While the availability of more rapid and shorter-acting anesthetic drugs (e.g., propofol,

sevoflurane, desflurane, remifentanil) has clearly facilitated the early recovery process after general

anesthesia, the preemptive use of non-opioid analgesics (e.g., local anesthetics, ketamine,

nonsteroidal antiinflammatory drugs, COX-2 inhibitors, acetaminophen)56 and antiemetics (e.g.,

droperidol, metoclopramide, 5-HT3 antagonists, dexamethasone)57, will reduce postoperative side

effects and accelerate both the immediate and late recovery phases after ambulatory surgery.

Multimodal approaches to preventing postoperative complications

As more complex procedures are performed utilizing minimally-invasive surgical approaches

(e.g., laparoscopic adrenalectomy, arthroscopic knee and shoulder reconstructions), the ability to

effectively control postoperative side effects may make the difference between performing a given

procedure on an inpatient or ambulatory basis. For routine antiemetic prophylaxis, the most cost-

effective combination consists of low-dose droperidol (0.5-1 mg) and dexamethasone (4-8 mg).58

Interestingly, dexamethasone appears to facilitate an earlier discharge independent of its effects on

PONV.59,60 Outpatients at high risk of PONV will benefit from the addition of a 5-HT3 antagonist

(e.g., ondansetron, dolasetron, granisetron)61,62 or an acustimulation device (e.g., SeaBand,

13

ReliefBand).63,64 Droperidol remains the most cost-efffective antiemetic assuming side effects can be

avoided.65,66 Although controversy exists regarding its potential for cardiac arrhythmias, droperidol

has remained a safe and effective antiemetic for over 30 years.67 An aggressive multimodal approach

to minimize PONV can improve the recovery process and enhance patient satisfaction.68 In addition to

utilizing combination antiemetic therapy, simply insuring adequate hydration will minimize nausea

and other side effects (e.g., dizziness, drowsiness, thirst) during the postoperative period.69

A multimodal (or “balanced”) approach to providing postoperative analgesia is also essential

in the ambulatory setting.70-72 Not surprisingly, pain has been found to be a major factor complicating

recovery and delaying discharge after ambulatory surgery.73 The addition of low-dose ketamine (75-

150 g/kg) to a multimodal analgesic regimen improved postoperative analgesia and functional

outcome after painful orthopedic surgery procedures.74,75 Following outpatient surgery, pain must be

controllable with oral analgesics (e.g., acetaminophen, ibuprofen, acetaminophen with codeine) before

patients are discharged from the facility. Although the potent rapid-acting opioid analgesics (e.g.,

fentanyl, sufentanil) are commonly used to treat moderate-to-severe pain in the early recovery period,

these compounds increase the incidence of PONV and may contribute to a delayed discharge after

ambulatory surgery.56,73 As a result of the concerns regarding opioid-related side effects, there has

been an increased interest in the use of potent non-steroidal anti-inflammatory agents (e.g., diclofenac,

ketorolac), which can effectively reduce the requirements for opioid-containing oral analgesics after

ambulatory surgery, and can lead to an earlier discharge home.76 Other less expensive oral non-

steroidal analgesics (e.g., ibuprofen, naproxen)77,78 may be acceptable alternatives to fentanyl and the

parenteral non-selective NSAIDs if administered in a pre-emptive fashion. Recently, premedication

with the COX-2 inhibitors (e.g., celecoxib, rofecoxib, valdecoxib, parecoxib) has become more

popular because they are devoid of potential adverse effects on platelet function.79 For routine clinical

use, oral premedication with rofecoxib (50 mg), celecoxib (400 mg) or valdecoxib (40 mg) is a simple

and cost-effective approach to improving pain control and decreased discharge times after ambulatory

surgery.80-84 The injectable COX-2 inhibitor, parecoxib, may prove useful in the future.85,86 Finally,

acetaminophen is a very cost-effective alternative to the COX-2 inhibitors if it can be given in a high

enough dose (40-60 mg/kg po or pr) prior to the end of surgery.87,88

One of the keys to facilitating the recovery process is the routine use of local anesthetics as

part of a multimodal regimen.56 Use of local anesthetic techniques for intraoperative analgesia during

MAC, as well as adjuncts to general (and spinal) anesthesia, can provide excellent analgesia during

the early postoperative recovery and postdischarge periods.4,18,19 Even simple wound infiltration and

instillation techniques have been shown to improve postoperative analgesia following a variety of

lower abdominal, peripheral extremity and even laparoscopic procedures. A wide variety of peripheral

extremity blocks have also been utilized to minimize postoperative pain.89,90 More recently, use of

continuous local anesthetic delivery systems (e.g., I-Flow) have been found to improve pain control

after major ambulatory orthopedic surgery by extending periopheral nerve blocks.91-93 Patient-

14

controlled local anesthetic delivery has also been described for improving pain relief after discharge

home.94 Following laparoscopic procedures, abdominal pain can also be minimized by the use of a

local anesthesia at the portals and topically applied at the surgical site.95,96 Shoulder pain is also

common following laparoscopic surgery, and this has been reported to be reduced with

subdiaphragmatic instillation of local anesthetic solutions.95 Following arthroscopic knee surgery,

instillation of 30 ml of bupivacaine 0.5% into the joint space reduces postoperative opiate

requirements and permits earlier ambulation and discharge.96 The addition of morphine (1-2 mg),

ketorolac (15-30 mg), clonidine (0.1-0.2 mg) and/or triamcinolone (10-20 mg) to the intraarticular

local anesthetic solution can further reduce pain after arthroscopic surgery.97-99 Electroanalgesia can

also be used as part of a multimodal treatment regimen.100 Future growth in the complexity of surgical

procedures being performed on an ambulatory basis will require further improvements in our ability

to provide effective postoperative pain relief outside the surgical facility (e.g., subcutaneous opioid

PCA, patient-controlled local anesthesia with a disposable infusion system, transcutaneous analgesic

delivery systems).

Summary

Ambulatory anesthesia has become recognized as an anesthetic subspecialty, with the

institution of formal postgraduate training programs. Expansion of the specialty of ambulatory

anesthesia and surgery is likely to continue with the growth in minimally-invasive (so-called keyhole)

surgical procedures. The rate of expansion of ambulatory anesthesia will probably vary depending

upon local needs, the level of ancillary home healthcare services, and economic considerations (101).

Many recently developed drugs have pharmacological profiles which are ideally suited for use in the

ambulatory setting. Use of newer anesthetic and analgesic drugs (e.g., desflurane, sevoflurane,

remifentanil, parecoxib) and brain monitoring systems (e.g., BIS, PSA, and AEP devices) should

facilitate fast-tracking in the ambulatory setting, leading to an early discharge after most surgery

procedures without compromising patient safety. To maintain the high level of patient safety,

mandatory accreditation and credentialing procedures are needed for both hospital-based and free-

standing ambulatory surgery facilities.102

Given the changing pattern of health care reimbursement, it is incumbent upon all practitioners to

carefully examine the impact of new drugs and devices on the quality of ambulatory anesthesia care

they are providing to the patient. Future studies on new drugs and techniques for ambulatory

anesthesia need to focus not only on subjective improvements for the patient during the immediate

perioperative period, but also on the overall cost-effectiveness of the care being provided.28 These

studies must compare the increased cost of newer treatments with the potential financial savings

resulting from earlier discharge home, reduced consumption of supplemental drugs, improvements in

15

patient satisfaction, and perhaps most importantly, resumption of normal activity. The future

challenge that all practitioners must face is to provide high-quality ambulatory anesthesia care for

more complex surgical procedures performed in a wide variety of venues. Finally, the need to

administer the most cost-effective anesthetic technique for a given ambulatory surgery procedure will

likely assume increased importance in the future.

References

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62. Zarate E, Watcha MF, White PF, et al. A comparison of the costs and efficacy of ondansetron versus dolasetron for antiemetic prophylaxis. Anesth Analg 2000 90: 1352-8.

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82. Recart A, Issioui T, White PF, et al: The efficacy of celecoxib premedication on postoperative pain and recovery times after ambulatory surgery: a dose-ranging study. Anesth Analg 2003; 96: 1631-5.

83. Watcha MF, Issioui T, Klein KW, White PF: Costs and effectiveness of rofecoxib, celecoxib and acetaminophen for preventing pain after ambulatory otolaryngologic surgery. Anesth Analg 2003: 96: 987-94.

84. Ma H, Tang J, White PF, et al. Perioperative rofecoxib improves early recovery after outpatient herniorrhaphy. Anesth Analg 2004; 98: 970-5.

85. Tang J, Li S, White PF, et al. Effect of parecoxib, a novel intravenous cyclooxygenase-2 inhibitor, on the postoperative opioid requirement and quality of pain control. Anesthesiology 2002; 96: 1305-9.

86. Desjardins PJ, Grossman EH, Kuss ME, et al. The injectable cyclooxygenase-2-specific inhibitor parecoxib sodium has analgesic efficacy when administered preoperatively. Anesth Analg 2001; 93: 721-7.

87. Rusy LM, Houck CS, Sullivan LJ, et al: A double-blind evaluation of ketorolac versus acetaminophen in pediatric tonsillectomy: analgesia and bleeding. Anesth Analg 1995; 80: 226-9.

88. Korpela R, Konvenoja P, Meretoja OA: Morphine-sparing effect of acetaminophen in pediatric day-care surgery. Anesthesiology 1999; 91: 442-7.

89. Ritchie ED, Tong D, Chung F, et al. Suprascapular nerve block for postoperative pain relief in arthroscopic shoulder surgery: A new modality? Anesth Analg 1997; 84: 1306-12.

90. Mulroy MF, Larkin KL, Batra MS, et al. Femoral nerve block with 0.25% or 0.5% bupivacaine improves postoperative analgesia following outpatient arthroscopic anterior cruciate ligament repair. Reg Anesth Pain Med 2001; 26: 24-9

91. Grant SA, Nielsen KC, Greengrass RA, et al. Continuous periopheral nerve block for ambulatory surgery. Reg Anesth Pain Med 2001; 26: 209-14.

92. Illfeld BM, Morey TE, Wang RD, Enneking FK. Continuous popliteal sciatic nerve for postoperative pain control at home. Anesthesiology 2002; 97: 959-65.

93. White PF, Issioui T, Skrivanek GD, et al. Use of a continuous popliteal sciatic nerve block for the management of pain after major podiatric surgery: does it improve quality of recovery? Anesth Analg 2003; 97: 1303-9.

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94. Rawal N, Axelsson K, Hylander J, et al: Postoperative patient-controlled local anesthetic administration at home. Anesth Analg 1998; 86: 86-9.

95. Pasqualucci A, de Angelis V, Contardo R, et al. Preemptive analgesia: Intraperitoneal local anesthetic in laparoscopic cholecystectomy. A randomized, double-blind, placebo-controlled study. Anesthesiology 1996; 85: 11-20.

96. Smith I, Shively RA, White PF. Effects of ketorolac and bupivacaine on recovery after outpatient arthroscopy. Anesth Analg 1992; 75: 208-12.

97. Stein C, Comisel K, Haimerl E, et al. Analgesic effect of intraarticular morphine after arthroscopic knee surgery. N Engl J Med 1991; 325: 1123-6.

98. Reuben S, Connelly NR. Postoperative analgesia for outpatient arthroscopic knee surgery with intraarticular clonidine. Anesth Analg 1999; 88: 729-33.

99. Wang JJ, Ho ST, Lee SC, et al. Intraarticular triamcinolone acetonide for pain control after arthroscopic knee surgery. Anesth Analg 1998; 87: 1113-6

100. White PF, Li S, Chiu JW: Electroanalgesia: its role in acute and chronic pain management. Anesth Analg 2001; 92: 505-13.

101. White PF: Ambulatory anesthesia advances into the new millennium. Anesth Analg 2000; 90: 1234-5.

102. Rohrich RJ, White PF. Safety of outpatient surgery: Is mandatory accreditation of outpatient surgery centers enough? Plastic Reconstr Surg 2001; 107:189-92.

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