Chapter 34 Outpatient Anesthesia
History of outpatient surgery and keys to success
1. Who created the first outpatient surgery center? When, where, and why?
2. What are the four most important areas to focus on to ensure success in outpatient anesthesia and surgery?
3. What are the primary determinants of predictability of duration and quality of surgical procedures in the ambulatory surgery center?
4. In comparison to hospital practice, is patient safety training usually less of a concern in an outpatient surgery setting, since patients are healthier and procedures are less invasive?
5. Is there value in monitoring of outcomes and the use of that data to support standard care practice (algorithms) and have these techniques been useful in creating higher quality care and improved patient safety?
Techniques of anesthesia for outpatient surgery
8. Monitored anesthesia care (MAC) may provide just as much risk as general anesthesia. What risk may be greater for MAC than general?
9. Use of regional anesthesia can result in what process improvements in the outpatient surgery suite?
10. Does neuraxial anesthesia delay discharge of outpatients, particularly elderly males?
11. Should neuraxial anesthesia be avoided because it has a high incidence of postoperative urinary retention?
12. The use of general anesthesia, when compared to regional anesthesia or MAC, increases the likelihood of which four negative outcomes in outpatient anesthesia and surgery?
13. Avoidance of what three anesthetic techniques will increase patient satisfaction, and decrease the likelihood of postoperative nausea and vomiting and postoperative cognitive dysfunction?
Topics of importance in outpatient anesthesia
14. What preoperative Hb A1c level indicates that it is “safe” for outpatient surgery to proceed?
15. What is the “rule of 1800” for dosing insulin and how is it useful on the day of surgery?
16. Is the use of dexamethasone appropriate to decrease the risk of postoperative nausea and vomiting in the patient with diabetes?
17. Is it true that treated hypertension is not a predictor of perioperative morbidity?
18. What are the considerations for deciding to provide anesthesia for a patient with a known or suspected personal history of malignant hyperthermia in a freestanding ambulatory surgical center?
19. Which risks are associated with obstructive sleep apnea (OSA)?
20. Of what value is preoperative evaluation and treatment of OSA?
21. What factors would lead to a patient with OSA being cared for in a hospital setting rather than a freestanding ambulatory surgery center?
22. What is the most common cause of perioperative injury associated with remote-site (e.g., office-based) surgery?
23. What factors increase the risk of perioperative trouble in the office setting?
24. What are the advantages of using multimodal analgesia in the outpatient surgery setting?
25. What postoperative plan should cause the team to reconsider the outpatient venue for a case?
26. How soon does tonsillectomy relieve moderate or severe obstructive sleep apnea in pediatric patients and what implication does that have for when and where this procedure should be performed in this patient population?
27. What postoperative complication do outpatient surgery patients rank the prevention of as high as they do the prevention and treatment of pain?
28. Use of the Apfel score to predict postoperative nausea and vomiting has proven valid only for which time period after surgery?
29. What regimen of prophylaxis can virtually eliminate both early and late postoperative and postdischarge nausea and vomiting (PONV/PDNV) in even the highest risk patients?
30. If PONV occurs after the use of ondansetron in the operating room, what should be used to treat it?
31. When should the presence of an upper respiratory infection lead to cancellation of an elective surgical procedure?
32. How should the availability of 23-hour stay facilities affect patient selection for outpatient surgery?
33. Should all patients remain at least 2 hours on site in a free-standing surgery center once in the recovery room (postanesthesia care unit [PACU])?
Answers*
History of outpatient surgery and keys to success
1. In 1917, after 100 years of hospital-based surgery made that venue the norm, Dr. Ralph Waters opened the first modern ambulatory surgery center in downtown Sioux City, Iowa. The name of his center (and the article he published describing it) emphasized the value of its practice to both patients and surgeons: “The Downtown Anesthesia Clinic.” His motivation was convenience and cost savings for patients, their families, and surgeons. (589)
2. The four most important areas to focus on to ensure success in outpatient anesthesia and surgery are:
3. The careful selection of patients and procedures, as well as the team that works in an operating suite is a primary determinant of the predictability of procedures in the outpatient surgery setting. (589)
4. Since there are fewer redundant systems in an outpatient center than in a hospital, it is more important that practitioners in the outpatient center are more highly trained and practiced in a wider variety of skill sets than would be true in the hospital. (589-590)
5. Evidence exists that the decrease in variation in care based on outcome measurement has provided improved quality of health care. (590)
Preoperative considerations
6. Laboratory and other testing should be used only if there is an aspect of a particular patient’s medical history that indicates such a need. For instance, the only patients who should have an ECG performed prior to outpatient surgery are those who are older than 65 years or who have a history of congestive heart failure, previous myocardial infarction, angina, high cholesterol, significant valvular disease, or a family history of sudden death. (591)
7. A myocardial infarction sustained within the past 3 months may not preclude a patient from having elective surgery in a freestanding surgery center, unless:
Techniques of anesthesia for outpatient surgery
8. MAC frequently involves the use of “blow by” oxygen and the close proximity of electrocautery or laser used by the surgeon, which increases the likelihood for fire. If a patient requires obtundation such that augmented inspiratory oxygen is required, and if electrocautery or laser will be in proximity to the airway, then the use of general anesthesia with a closed airway device (laryngeal mask airway or endotracheal tube) may well be safer than MAC. (592)
9. Regional anesthesia can decrease overall anesthesia time and do so without increasing turnover time duration. PACU time can also be decreased. (592)
10. Neuraxial anesthesia, particularly with the use of a low-dose or short-acting agent (such as 2-chloroprocaine), does not delay discharge when compared to general anesthesia. (592)
11. Postoperative urinary retention (POUR) is associated less with anesthesia technique since both neuraxial and general anesthesia impact the autonomic system. Assuming reasonable choices of drugs and doses are made with each, POUR is associated more with the nature of the patient (age, preexisting benign prostatic hyperplasia, neurologic disease) and procedure (duration, rectal, urinary, or inguinal procedures). An algorithm for the management of POUR should be created and include the use of ultrasound evaluation of the bladder volume. (612)
12. The use of general anesthesia for outpatient surgery increases the risk of PONV/PDNV, postoperative cognitive dysfunction, and delayed discharge when compared to MAC or regional anesthesia. (592)
13. PONV and postoperative cognitive dysfunction can be diminished by avoiding (1) preoperative and intraoperative opioid in lieu of multimodal analgesia, (2) general anesthesia instead of or in addition to regional anesthesia, and (3) inhaled anesthetics in lieu of total intravenous anesthesia. (593)
Topics of importance in outpatient anesthesia
14. There is no evidence that a specific Hb A1c level indicates any guarantee of safety, but a level of 7 or lower is an indication that a patient with diabetes has it in good control. A higher level, combined with other indications of comorbidity, should be a concern to the anesthesiologist consultant that risk is higher. The highest value of the lab test is to provide guidance to the patient’s primary physician to adjust medication doses to improve control, far enough in advance to potentially improve the level of risk incurred by the patient in the perioperative period. (593)
15. The rule of 1800 is a good approach to dosing insulin on the day of surgery. In this paradigm, the number 1800 is divided by the patient’s normal daily insulin dose (i.e., the total daily dose of all forms of insulin, including basal and boluses, or long and shorter acting, taken in a typical 24-hour period). The result determines the probable change in glucose level (mg/dL) that would be anticipated by the use of a single unit of regular insulin. (593)
16. One must alert the patient to the likelihood of blood sugar elevations after any surgical procedure, with or without the use of dexamethasone. It is unusual that antiemetic doses of dexamethasone would elevate the blood glucose to a degree notable apart from the elevation induced by the surgical procedure itself. (594)
17. Hypertension, treated or untreated, is an independent variable that correlates positively with perioperative morbidity. (594)
18. Prior to deciding that a freestanding facility is the appropriate venue to provide anesthesia for a patient with a known or suspected personal history of malignant hyperthermia, the requirement should be that the center can replicate exactly the standard of care for treatment of a malignant hyperthermia episode. This would include more than 36 vials of dantrolene (more than 36 are needed in view of the increased incidence of obesity), blood gas capability, and ready availability of intensivists, respiratory therapists, and ventilators such that early stabilization and transfer to the hospital will be of equivalent safety to the care that would be provided in the hospital (595)
19. Patients with OSA are at increased risk for cerebrovascular events, myocardial infarction, bleeding, and perioperative respiratory events (e.g., difficult intubation). (595)
20. The value of preoperative evaluation and delineation of OSA severity is that patients with OSA can be treated with continuous positive airway pressure (CPAP) for a few weeks and thereby decrease their risk. CPAP therapy can induce decreases in blood pressure readings, tongue and hypopharyngeal muscle size, and result in less bleeding in the postoperative period. (595)
21. Recognition of moderate or severe OSA combined with a need for general anesthesia and a likely need for moderate doses of opioid should lead to a decision to provide overnight or hospital care in view of the high risk for respiratory impairment due to the unobserved use of opioids. (596)
22. Inadequate monitoring is the most frequent cause of injury associated with anesthesia provided at off-site locations. (596)
23. Factors associated with increased risk of perioperative mishap in the office setting include the use of unqualified providers for either surgery or anesthesia and a lack of appropriate equipment and training for resuscitation and other emergencies, as well as inadequate access (delayed transfer) to hospitals. (596)
24. The various therapies used for multimodal analgesia provide high patient satisfaction and opportunities for fast-tracking. They decrease acute and chronic postoperative pain and therefore the need for postoperative opioids. They also decrease PONV, time to discharge, and reduce immune suppression and tumor metastasis. (596)
25. Anticipation of a requirement for significant opioid doses for postoperative analgesia is a good reason to redirect the case to the inpatient setting. (596)
26. Pediatric tonsillectomy performed for moderate or severe obstructive airway disease actually results in increased obstruction, not relief, in the first 24 hours after surgery. This is the reason that both ENT and anesthesiology professional society guidelines recommend against performance of tonsillectomy in children 36 months or younger as outpatients (597)
27. PONV is a postoperative complication that patients rank as high as they rank postoperative pain. (597)
28. The Apfel score is predictive for the incidence of onsite PONV but not for PDNV. (597)
29. A regimen of both IV dexamethasone 8 mg and ondansetron 4 mg intraoperatively, followed by oral tablets of 8 mg ondansetron at discharge and on postoperative days 1 and 2, can virtually eliminate early and late PONV/PDNV in even the highest risk patients. (597)
30. If nausea or vomiting occurs in the PACU despite use of IV ondansetron intraoperatively, it is more effective to use small doses (6.25 mg) of intravenous promethazine rather than repeat the use of ondansetron. (597)
31. The presence of an upper respiratory infection should lead to cancellation of an elective outpatient surgical case if the planned surgical procedure requires endotracheal intubation, the patient has underlying cardiac or pulmonary comorbidities, or the procedure will directly impact the airway. Irrespective of comorbidities or the type of procedure to be done, the presence of systemic symptoms (fever, malaise), wheezing, or dyspnea should also lead to postponement. (598)
32. The presence of 23-hour overnight stay facilities onsite should potentially increase the variety of surgical procedures that can be done, but not affect the patient health criteria for admission to an outpatient surgery center. Whereas such facilities can provide the option to manage surgical-related issues (e.g., drains, IV PCAs) they do not change the safety equation regarding patients with unstable cardiovascular conditions or obstructive sleep apnea, for example. (606)
33. Use of the postanesthetic discharge scoring system (PADSS) allows patients to be discharged safely without a minimum time requirement in the recovery room. (612)
