Patient Selection for Adult Ambulatory Surgery

A Narrative Review

Niraja Rajan, MD; Eric B. Rosero, MD, MSc; Girish P. Joshi, MBBS, MD, FFARCSI

Anesth Analg. 2021;133(6):1415-1430.

System Factors and Patient Selection

Recommendations and mandates from local, state, and national regulatory organizations influence decision-making regarding patient selection. For example, CMS limits ASCs to providing surgical services that do not require hospitalization and duration of such services would not exceed 24 hours.^[12] Also, certain states have restrictions on types and length of procedures or upper and lower age limits for patients who may undergo a procedure in the ambulatory setting. For example, in Pennsylvania, children <6 months of age may not undergo surgery in an ASC.^[13] Although these regulatory restrictions may not be based on current evidence, they must be followed.

The type of surgical facility also influences patient selection.^[14] Unlike an ambulatory surgical facility that is physically connected to a hospital, a freestanding ASC may not be able to perform procedures on and care for patients of higher acuity because of lack of consultation and ancillary services, as well as lack of laboratory or blood bank services. Certain low-risk procedures such as cataract surgery or cystoscopy may be safely performed at freestanding ASCs on higher risk patients who would not qualify for a more invasive procedure at the same facility. Patient selection should be customized to each ASC based on its location and availability of consult and ancillary services.

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Abstract and Introduction
Perioperative Outcomes and Patient Selection
System Factors and Patient Selection
Surgical Procedure and Patient Selection
Social Factors and Patient Selection
Patient Comorbid Conditions and Patient Selection
Summary
References

Table 1. ASA-PS Classification
ASA-PS classification	Definition	Adult examples, including, but not limited to
I	A normal healthy patient	Healthy, nonsmoking, no or minimal alcohol use
II	A patient with mild systemic disease	Mild diseases only without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30 kg/m² < body mass index <40 kg/m²), well-controlled diabetes mellitus or hypertension, mild lung disease
III	A patient with severe systemic disease	Substantive functional limitations; 1 or more moderate to severe diseases. Examples include (but not limited to): poorly controlled diabetes mellitus or hypertension, chronic obstructive pulmonary disease, morbid obesity (body mass index ≥40 kg/m²), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, end-stage renal disease undergoing regularly scheduled dialysis, history (>3 mo) of myocardial infarction, cerebrovascular accident, transient ischemic attack, or coronary artery disease/stents
IV	A patient with severe systemic disease that is a constant threat to life	Examples include (but not limited to): recent (<3 mo) myocardial infarction, cerebrovascular accident, transient ischemic attack, or coronary artery disease/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, disseminated intravascular coagulation, adult respiratory distress, or end-stage renal disease not undergoing regularly scheduled dialysis
V	A moribund patient who is not expected to survive without the operation	Examples include (but not limited to): ruptured abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in the face of significant cardiac pathology or multiple organ/system dysfunction
VI	A declared brain-dead patient whose organs are being removed for donor purposes

Abbreviation: ASA-PS, American Society of Anesthesiologists physical status.
The addition of "E" denotes emergency surgery: an emergency is defined as existing when delay in treatment of the patient would lead to a significant increase in the threat to life or body part.

Table 2. Summary of Recommendations
Comorbidity	Summary of recommendations
ASA physical status	• ASA physical status III patients should have optimized stable comorbidities
ASA physical status	• ASA physical status IV patients with stable comorbid conditions may undergo low-risk procedures such as cataract surgery performed under topical/local/regional anesthesia
Age/frailty	• Age alone should not be an exclusion factor. Consider comorbid conditions, frailty, cognitive status, surgical, anesthetic, and social factors such as lack of home care support or unwillingness of patient to comply
Obesity	• BMI <40 kg/m²: suitable for ambulatory surgery
	• BMI 40–50 kg/m²: optimize comorbidities and screen for obstructive sleep apnea
	• BMI >50 kg/m²: schedule as outpatient for low-risk procedures in the absence of severe cardiopulmonary comorbidities
Obstructive sleep apnea	• Screen for obstructive sleep apnea and optimize comorbidities
	• Preoperative sleep study is not required
	• Encourage positive airway pressure use in compliant patients
	• Pain control with multimodal nonopioid analgesia
Cardiac disease	• Asymptomatic cardiac patients do not require cardiac testing
	• Do not postpone surgery based solely on a blood pressure values. Delay only for patients with malignant hypertension (diastolic blood pressure >110 mm Hg) with acute end-organ damage
	• Exclude for at least 30 d after acute myocardial infarction
	• Exclude only for patients with decompensated, new onset, or untreated heart failure as well as symptomatic patients with low (<35%) left ventricular ejection fraction
	• Exclude symptomatic (fatigue, dizziness, syncope, palpitations, chest pain, and shortness of breath) patients with new onset atrial fibrillation
	• Exclude symptomatic (chest pain, dyspnea, syncope, and poor exercise tolerance) patients severe valvular heart disease
	• Patients with coronary stents are suitable if comorbidity burden is low, sufficient time has elapsed since stent implantation (30 d for BMS, 6 mo for newer DES, 12 mo for older DES) allowing for interruption of dual antiplatelet therapy, patient has transitioned to a state of stable ischemic coronary disease, or if procedure is noninvasive, allowing continuation of dual antiplatelet therapy with low risk of bleeding.
	• Patients with cardiac electronic implantable devices are suitable if the potential for electromagnetic interference is low, and with ability to manage the device if use of magnet or reprogramming is necessary
Chronic obstructive pulmonary disease	• Exclude severe disease. Encourage smoking cessation, optimize bronchodilator therapy, treat respiratory infection
Diabetes mellitus	• Continue antidiabetic drugs, as appropriate
	• Resume oral intake and hypoglycemic regimen as soon as possible postoperatively
	• Exclude unstable metabolic conditions such as diabetic ketoacidosis, and nonketotic hyperosmolar states
End-stage renal disease	• Exclude if not on dialysis, optimize comorbidities, accept chronic anemia and asymptomatic hyperkalemia (K ≤ 6.0)
Previous stroke/transient ischemic attack	• Delay elective surgery for at least 9 mo
Previous stroke/transient ischemic attack	• Manage antiplatelet therapy
Malignant hyperthermia susceptible	• Proceed as outpatient using nontriggering anesthetics
Malignant hyperthermia susceptible	• Malignant hyperthermia cart and dantrolene available in facility
Chronic pain/opioid use disorder	• Procedures with expected mild/moderate pain manageable with nonopioid analgesia including local/regional analgesia may be scheduled as outpatient
Chronic pain/opioid use disorder	• Procedures with expected severe pain or requiring tapering of maintenance regimens should be scheduled as inpatient