Candidates for Ambulatory and Office Based Anesthesia

CANDIDATES FOR AMBULATORY AND OFFICE BASED ANESTHESIA

With an aging and increasingly obese population, patients with significant comorbidities present for ambulatory surgery. Although age per se is not a fac-tor in determining candidacy for ambulatory proce-dures, each patient must be considered in the context of his or her comorbidities, the type of surgery to be performed, and the expected response to anesthesia.

In general, ambulatory surgeries should be of a complexity and duration such that one couldreasonably assume that the patient will make an expeditious recovery. ASA physical status and a thorough history and physical exam are crucial in the screening of patients selected for ambulatory or office-based surgery. ASA 4 and 5 patients normally would not be candidates for ambulatory surgery, whereas ASA 1 and 2 patients would be prime can-didates for such surgery. ASA 3 patients with diabe-tes, hypertension, and stable coronary artery disease would not be precluded from an ambulatory proce-dure provided that their diseases are well controlled. Ultimately, the surgeon and anesthesia provider must identify patients for whom an ambulatory or office-based setting is likely to provide benefits (eg, convenience, reduced costs and charges) that outweigh risks (eg, the lack of immediate availability of all hospital services, such as a cardiac catheteriza-tion laboratory, emergency cardiovascular stents, assistance with airway rescue, rapid consultation).

Factors considered in selecting patients for ambulatory procedures include: systemic illnesses and their current management, airway man-agement problems, sleep apnea, morbid obesity, previous adverse anesthesia outcomes (eg, malignant hyperthermia), allergies, and the patient’s social net-work (eg, availability of someone to be responsive to the patient for 24 h).

Patients with known or likely difficult airways should probably not be candidates for office-based procedures; however, they may be appropriately cared for in a well equipped and fully staffed ambu-latory surgery center. Important considerations for such patients include the availability of difficult airway equipment, such as an intubating LMA or videolaryngoscope, the availability of additional experienced anesthesia providers, and surgeons/ anesthesiologists capable of performing emergency tracheostomy/cricothyroidotomy. If there are con-cerns regarding the ability to manage the airway in an ambulatory surgery setting, or if a surgical air-way is thought to be a possibility, the patient may be better served in a hospital setting where immediate consultation and assistance is available.

Similarly, patients with unstable comorbid con-ditions, such as decompensated congestive heart failure or uncontrolled hypertension, may benefit more from having their procedure performed in a hospital than a free-standing facility. Indeed, many patients undergo ambulatory procedures in a hos-pital, as opposed to a free-standing surgery center or office. Such patients have the benefit of both the availability of a hospital’s resources and the conve-nience of being an ambulatory patient. Should their condition warrant additional care, hospital admit-tance is possible; however, such flexibility comes with the costs associated with hospital care.

The anesthesiologist must know which preexist-ing medical conditions predict a specific intraopera-tive and/or postoperative adverse event (AE) for the patient in question. Likewise, procedures suitable for ambulatory surgery should have a minimal risk of perioperative hemorrhage, airway compromise, and no particular requirement for specialized postopera-tive care. Based on risk identification, the anesthe-siologist should be able to mitigate unforeseen AEs and provide optimal care for patients in this type of setting. Although current evidence-based medicine can provide recommendations for some high-risk ambulatory issues, evidence is lacking for most such situations.