Screening prior to outpatient surgery is important. Over 70% of elective surgeries in the United States are ambulatory or outpatient surgeries, in which the patient goes home the same day as the procedure. There are increasing numbers of surgical patients who are elderly, obese, have sleep apnea, or who have multiple medical problems. How do we decide which 70% of surgical candidates are appropriate for outpatient surgery, and which are not?
For the past 16 years I’ve been the Medical Director at a busy Ambulatory Surgery Center (ASC) in Palo Alto, California. ASC Medical Directors are perioperative physicians, responsible for the preoperative, intraoperative, and postoperative management of ambulatory surgery patients. Our surgery center is freestanding, distanced one mile from Stanford University Hospital. The hospital-based technologies of laboratory testing, a blood bank, an ICU, arterial blood gas measurement, and full radiology diagnostics are not available on site. It’s important that patient selection for a freestanding surgery center is precise and safe.
The topic of Ambulatory Anesthesia is well reviewed in the textbook Miller’s Anesthesia, 7th Edition, 2009, Chapter 78, Ambulatory (Outpatient) Anesthesia. With the information in this chapter as a foundation, the following 7 points are guidelines I recommend in the preoperative consultation and selection of appropriate outpatient surgery patients:
- The most important factor in deciding if a surgical case is appropriate is not how many medical problems the patient has, but rather the magnitude of the surgical procedure. A patient may have morbid obesity, sleep apnea, and a past history of congestive heart failure, but still safely undergo a non-invasive procedure such as cataract surgery. Conversely, if the patient is healthy, but the scheduled surgery is an invasive procedure such as resection of a mass in the liver, that surgery needs to be done in a hospital.
- Because of #1, an ASC will schedule noninvasive procedures such as arthroscopies, head and neck procedures, eye surgeries, minor gynecology and general surgery procedures, gastroenterology endoscopies, plastic surgeries, and dental surgeries. What all these scheduled procedures have in common is that the surgeries (a) will not disrupt the postoperative physiology in a major way, and (b) will not cause excessive pain requires inpatient intravenous narcotics.
- One must screen patients preoperatively to identify individuals who have serious medical problems. Our facility uses a comprehensive preoperative telephone interview performed by a medical assistant, two days prior to surgery. The interview documents age, height, weight, Body Mass Index, complete review of systems, list of allergies, and prescription drug history. All information is entered in the patient’s medical record at that time.
- Each surgeon’s office assists in the preoperative screening. For all patients who have (a) age over 65, (b) obstructive sleep apnea, (c) cardiac disease or arrhythmia history, (d) significant lung disease, (e) shortness of breath or chest pain, (f) renal failure or hepatic failure, (g) insulin dependent diabetes, or (h) significant neurological abnormality, the surgery office is required to obtain medical clearance from the patient’s Primary Care Provider (PCP). This PCP clearance note concludes with two questions: 1) Does the patient require any further diagnostic testing prior to the scheduled surgery? And 2) Does the patient require any further therapeutic measures prior to the scheduled surgery?
- For each patient identified with significant medical problems, the Medical Director must review the chart and the Primary Care Provider note, and confirm that the patient is an appropriate candidate for the outpatient surgery. The Medical Director may telephone the patient for a more detailed history if indicated. On rare occasions, the Medical Director may arrange to meet and examine the patient prior to the surgical date.
- Medical judgment is required, as some ASA III patients with significant comorbidities are candidates for trivial outpatient procedures such as gastroenterology endoscopy or removal of a neuroma from a finger, but are inappropriate candidates for a shoulder arthroscopy or any procedure that requires general endotracheal anesthesia.
- What about laboratory testing? Per Miller’s Anesthesia, 7th Edition, 2009, Chapter 78, few preoperative lab tests are indicated prior to most ambulatory surgery. We require a recent ECG for patients with a history of hypertension, cardiac disease, or for any patient over 65 years in age. If this ECG is not included with the Primary Care Provider consultation note, we perform the ECG on site in the preoperative area of our ASC, at no charge to the patient. All diabetic patients have a fasting glucose test done prior to surgery. No electrolytes, hematocrit, renal function tests, or hepatic tests are required on any patient unless that patient’s history indicates a specific reason to mandate those tests.
Utilizing this system, cancellations on the day of surgery are infrequent—well below 1% of the scheduled procedures. The expense of and inconvenience of an Anesthesia Preoperative Clinic are eliminated.
What sort of cases are not approved? Here are examples from my practice regarding patients/procedures who are/are not appropriate for surgery at a freestanding ambulatory surgery center:
- A 45-year-old patient with moderately severe obstructive sleep apnea (OSA) is scheduled for a UPPP (uvulopalatalpharyngoplasty). DECISION: NOT APPROPRIATE. Reference: American Society of Anesthesiologist Practice Guidelines of the Perioperative Management of Patients with OSA (https://www.asahq.org/coveo.aspx?q=osa). For airway and palate surgery on an OSA patient, the patient is best observed in a medical facility post-surgery. For any surgery this painful in an OSA patient, the patient will require significant narcotics, which place him at risk for apnea and airway obstruction post-surgery.
- A morbidly obese male (Body Mass Index = 40) is scheduled for a shoulder arthroscopy and rotator cuff repair. DECISION: NOT APPROPRIATE. Obesity is not an automatic exclusion criterion for outpatient surgery. Whether to cancel the case or not depends on the nature of the surgery. A shoulder repair often requires significant postoperative narcotics. The intersection of morbid obesity and a painful surgery means it’s best to do the case in a hospital. One could argue that this patient could be done with an interscalene block for postoperative analgesia and then discharged home, but I don’t support this decision. If the block is difficult or ineffective, the anesthesiologist has a morbidly obese patient requiring significant doses of narcotics, and who is scheduled to be discharged home. If this surgery had been a knee arthroscopy and medial meniscectomy it could be an appropriate outpatient surgery, because meniscectomy patients have minimal pain postoperatively.
- An 18-year-old male with a positive family history of Malignant Hyperthermia is scheduled for a tympanoplasty. DECISION: APPROPRIATE. A trigger-free general total-intravenous anesthetic with propofol and remifenantil can be given just as safely in an ASC as in a hospital.
- A 50-year-old 70-kilogram male with a known difficult airway (ankylosing spondylitis) is scheduled for endoscopic sinus surgery. DECISION: APPROPRIATE. In our ASC, for safety reasons, we have advanced airway equipment including a video laryngoscope and a fiberoptic laryngoscope. If a patient needs an awake intubation, we are prepared to do this safely. This case would be scheduled with a second anesthesiologist available to assist the primary anesthesia attending in securing the airway.
- An 80-year-old woman with shortness of breath on exertion is scheduled for a bunionectomy. DECISION: NOT APPROPRIATE. Although foot surgery is not a major invasive procedure, any patient with shortness of breath is inappropriate for ASC surgery. The nature of the dyspnea needs to be determined and remedied prior to surgery or anesthesia of any sort.
- A 6-year-old female born without an ear is scheduled for a 9-hour ear graft and reconstruction. DECISION: APPROPRIATE. With modern general anesthetic techniques utilizing sevoflurane and propofol, patients awake promptly. Even after long anesthetics, if the surgery is not painful, patients are usually discharged in stable condition within 60-90 minutes.
There are infinite combinations of patient comorbidities and types of surgeries. The decision regarding which scheduled procedures are appropriate and which are not is both an art and a science. The role of an anesthesiologist/Medical Director as the perioperative physician making these decisions is invaluable.
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Published in September 2017: The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.
In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.
Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.
Nuanced characterization and crafty details help this debut soar.
Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:
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