#365: Perioperative Medicine with Anesthesiologist Dr. Angela Selzer

November 7, 2022 | By Matthew Watto, MD

Video

We’ve Come a Long Way From Ether

Subtitle: We’ve Come a Long Way From Ether

Learn how an anesthesiologist approaches perioperative medicine from how to choose the right type of anesthesia (general anesthesia vs regional anesthesia vs MAC), to preoperative risk assessment, and how to avoid anesthesia related complications. Our guest, anesthesiologist, Dr. Angela Selzer (Denver, CO) helps us explore high yield pearls regarding the practice of anesthesiology to empower the internal medicine clinician to deliver team-based, perioperative care.

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Credits

• Written and Produced by: Edison Jyang; Avital O’Glasser MD, FACP, SFHM
• Cover Art: Sarah Phoebe Roberts, MPH
• Infographic:  Avital O’Glasser MD, FACP, SFHM; Edison Jyang
• Show Notes: Avital O’Glasser MD, FACP, SFHM
• Hosts: Matthew Watto MD, FACP; Avital O’Glasser MD, FACP, SFHM
• Technical Production: Pod Paste 
• Reviewer: Sai S Achi, MD MBA
• Showrunner: Matthew Watto MD, FACP
• Technical Production: PodPaste
• Guest: Angela Selzer, MD

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CME Partner: VCU Health CE

Show Segments

• Intro, disclaimer, guest bio
• Guest one-liner
• Introduction to anesthesiology 
• Introduction to regional anesthesiology  
• Walk through what an anesthesiologist does in the operating room
• Ambulatory surgery center exclusions 
• Approach to preop assessments
• “Will it change management?” applied to anesthesiologists
• ASA Classes 
• Anesthesia complications
• Take Home Points; Outro; Bonus clip

Anesthesia for the Internist Pearls

1. Advantages to regional anesthesia over general anesthesia can include less postoperative nausea and vomiting (PONV), less post-anesthetic “hangover”, faster awakening, and fewer postoperative narcotic needs.
2. Currently there is still NO robust evidence to prove regional anesthesia lowers the risk of postop delirium or cognitive dysfunction over general anesthesia.
3. Contraindications to regional anesthesia include insufficient anticoagulation hold times, coagulopathy, infection at the injection site, or a need to monitor neuromuscular function postop.
4. Sugammadex, a reversal agent, can decrease the effectiveness of hormonal contraception—counsel on backup/alternative contraception.
5. Even if certain tests (e.g. ECHO, stress test) may not change outpatient management for non-anesthesiologists, they can inform anesthesiology intraop management, especially in patients with significant functional limitations.
6. For ECHOs, determining the type of heart failure, especially left heart versus right heart, can lead to dramatic differences in intraop management.
7. An abnormal stress test doesn’t automatically mean catheterization and stent placement. They can be useful tools for intraop management in the right patient.
8. It’s very hard to be an ASA 1 as an adult!  If a patient is pregnant, or if they drink alcohol socially, they are an ASA 2.

Anesthesiology for the Non-Anesthesiologist

“The most important thing that we do… is creating safe surgical conditions.” ~ Dr. Selzer

What is anesthesia?

“Anesthesia” refers to a broad spectrum of care provided, both in the traditional operating room setting and outside the operating room.  The primary goal of anesthesia is to provide safe surgical conditions, and this can be accomplished in many ways.  More specific goals are to maintain a balanced physiologic state while achieving a state of amnesia and analgesia .

Types of anesthesia:

• MAC (monitored anesthesia care): broad spectrum, includes anytime an anesthesiologist is present to monitor and support a patient through a case.
• General anesthesia (GA): anytime a patient is sedated to the point where they are unresponsive to painful stimuli.  Patients may be breathing on their own without an airway device and be under general anesthesia. However, any anesthetic with an endotracheal tube or laryngeal mask airway (LMA) is considered a general anesthetic.  Medications administered during GA can be volatile (inhaled) agents,  total intravenous anesthesia (TIVA) with agents like propofol or a combination of both. 
• Regional anesthesia: numbing or anesthetizing specific regions of the body, including the potential for proximal extremity blocks or neuraxial anesthesia (e.g. epidural).  Regional anesthesia techniques are standard training for all anesthesiologists but with the increasing complexity of regional anesthesia some anesthesiologists complete an extra year of training in an acute pain and regional anesthesia fellowship program. 

Criteria number one for a patient to receive regional anesthesia is the informed consent from the patient.  There are many advantages to regional anesthesia over general anesthesia, including better experience overall, less postoperative nausea and vomiting (PONV), less post-anesthetic “hangover”, faster awakening, and fewer postoperative narcotic needs.  Physiologically, the risk of postop delirium or cognitive dysfunction intuitively feels like it would be lower with regional anesthesia versus general anesthesia—but there is currently no robust evidence to support this.

Contraindications to neuraxial anesthesia may include: patient refusal, insufficient anticoagulation hold times (ASRA anticoagulation guidelines 2018), underlying coagulopathy, infection at the local injection site,  or certain pathologic conditions.  The 2021 REGAIN trial did not show that spinal anesthesia was superior to GA for survival and recovery of ambulation after hip fracture surgery.  Dr. Selzer’s interpretation of this data is that hip fracture patients are often complex and medically fragile and may have many confounders in studying their periop outcomes (BONUS–this was also reviewed for NEJM Journal Watch by Curbsider Dr. Rahul Ganatra!)

Institutional memory might be a large driving factor for what type of anesthesia is preferred for a given case.  ALWAYS make it a conversation—between the anesthesiologist, surgeon, AND patient.

What do anesthesiologists do in the operating room?

“This is like preparing for Thanksgiving dinner.  You know your guests are coming at a certain time, you got to get the turkey ready, you want the sides ready–there’s a lot of things going on.” ~ Dr. Selzer

Anesthesia is not delivered with an “on/off” switch (no matter what Dr. Glaucomflecken says…).  Even in a straightforward case with a healthy patient, “smooth sailing” consists of frequent adjustments in the OR—and certainly more are possible for a high-risk, unstable patient. What medications and interventions might a patient (potentially) receive for a standard surgery with general anesthesia?

1. Midazolam for anxiolysis.
2. Preoxygenation before intubation and induction of anesthesia.
3. Induction with agents such as fentanyl, lidocaine, propofol, rocuronium (muscle relaxant).
4. Transition to volatile anesthetics (sevoflurane usually), or TIVA (usually propofol, dexmedetomidine, or remifentanil) for anesthesia maintenance.
5. Narcotics and multimodal analgesics for periop pain.
6. Antiemetics for PONV prophylaxis.
7. Titrating anesthesia off to transition to emergence period
8. Reversal of neuromuscular blockade
   1. PEARL: sugammadex, a reversal agent, can decrease the effectiveness of hormonal contraception—patients need appropriate counseling to use a backup contraceptive.
9. Extubation when breathing adequately without support, pain well controlled and following commands. 

An anesthesiologist’s approach to preoperative assessments

Anesthesiologists take care of patients during a really critical period, and the surgeries they have can be very intense and stressful, and as much information as you can give us on that patient’s functional status, on their medical history, on whether or not those medical problems are optimized is really helpful for us take better care of the patient.  Just letting us know that the patient is “cleared” is not helpful.” ~ Dr. Selzer

It’s NOT about “clearance”, and it’s not only about the stress test (or lack thereof).  Functional tolerance is a key element of preoperative assessments and histories, as can be primary records from past testing. Dr. O’Glasser’s periop mantra: knowledge is empowering!

“If it will change management…”

Whether or not a preop test (like an ECHO) will change management might be answered differently by an outpatient PCP, inpatient hospitalist, and anesthesiologist.  Our job as non-anesthesiologists may require us to think like an anesthesiologist as much as possible, and consider how a test will inform and empower intraoperative management decisions.

Depending on the patient, especially those with significant functional limitations, certain tests can be very helpful for an anesthesiologist’s management in the operating room. For example:

• ECHO: determining how well the heart functions, the presence of right or left heart failure,  or the presence of valvular disease can lead to dramatic differences in physiologic responses to anesthesia and greatly impact intraoperative management decisions. 
• Stress test: an abnormal stress test doesn’t automatically lead to catheterization and stent placement.  A stress test, especially for a symptomatic patient, even before time-sensitive surgery (i.e. one that can’t be delayed for a period of uninterrupted dual antiplatelet therapy) may STILL change and inform intraop management—including monitoring and management decisions—as well as inform risk counseling discussions.

Give me a number between one and six…

“The words “pulmonary” and “hypertension” are fairly benign on their own, but when you remove the “and” and say “pulmonary hypertension”, it becomes a really big problem for anesthesiologists.” ~ Dr. Selzer

The ASA classification system was developed several decades ago to standardize periop outcomes research based on patient complexity.  ASA classes 1–6 exist, plus there is an “e” (emergency) modifier.

It’s very hard to be an ASA 1 as an adult!  Even social alcohol consumption earns a patient an ASA 2 status, and pregnancy = ASA 2 class.  BMI > 40 is at least an ASA 3 patient.  There is a lot of interpersonal variability between ASA 2 and 3, and between ASA 3 and 4 (Haynes 1995, Ranta 1997, Mak 2002)—and making those distinctions can be really challenging (though adding narrative examples as a reference improves scoring)!  An ASA 3 patient has substantive functional limitations; an ASA 4 patient has a condition that is a constant threat to life.  Dr. Selzer’s teaching PEARL to determine ASA 3 versus 4: would you be surprised if a patient with the same pathology died suddenly while grocery shopping? If not, and you could easily determine a likely etiology, they are very likely an ASA 4 patient. 

Why does OR location matter?

Ambulatory surgery can be a higher risk setting for certain patients. This is another reason why an appropriately thorough preop assessment of patient comorbid conditions is important to triage location of surgery (remember, “knowledge is empowering”!) (Mathis 2013, Whippey 2013).

Anesthesia care has also expanded to the non-operating room setting (NORA).  Very commonly this is GA for MRIs, but this can also be provided for any non-OR based procedure (including interventional cardiology, electrophysiology, gastroenterology, and interventional radiology).

While many NORA cases are performed without anesthesia, this may be unsafe in certain patient populations, including children, patients with neuropsychiatric conditions and patients with complex medical comorbidities. These patients may benefit from an anesthesia team dedicated to achieving a safe level of anesthesia, monitoring vital signs and assisting with ventilation during their procedure. 

What is a complication of anesthesia (or not)?

A patient may report a history of a complication of anesthesia when they actually had an expected periop course. Again, “knowledge is empowering”—try to get more details about what happened.

Delayed emergence due to a pseudocholinesterase deficiency is rare.  “Trouble waking up” in the PACU may not be true delayed emergence—it may be on the expected continuum of post-anesthesia grogginess or a sign of something like underlying OSA. Someone with true delayed emergence might need to remain intubated and “wake up” in the ICU well after surgery is completed.

Intraoperative awareness due to rapid metabolism of agents (and waking up paralyzed and aware of surgery going on) is also exceedingly rare.  If a patient says they woke up during a case, get the records to tease out if this was done with a lighter level of sedation (e.g. with or without regional anesthesia).  TIDBIT: natural redheads need more anesthesia drug doses to stay asleep! 

Malignant hyperthermia is also extremely rare but can be life threatening!  Knowing a patient has malignant hyperthermia or even family members who had malignant hyperthermia (or an intraop death) WILL change periop management as all volatile anesthetics need to be removed from the room, machines cleaned differently, and triggering agents avoided.

Take Home Points

1. Anesthesia is delivered on a spectrum from light sedation to general anesthesia. 
2. Knowledge is empowering—our anesthesiologist colleagues need information about comorbid conditions and functional capacity to inform the safest intraop care and management.
3. Consider how a test might inform or change an anesthesiologist’s management, as periop and chronic health guidelines may differ in terms of testing recommendations. 
4. Make friends with an anesthesiologist and have someone to ask questions to.

Plugs

1. The Bear (TV Series)
2. The Society for Perioperative Assessment and Quality Improvement (SPAQI)
3. Dr. Glaucomflecken’s videos about anesthesiologists

Other Stuff

Glossary:

MAC: monitored anesthesia care

LMA: laryngeal mask airway 

GA: general anesthesia 

TIVA: total intravenous anesthesia

PONV: postoperative nausea and vomiting

NORA: non-operating room anesthesia

Links*

1. Dr. Selzer’s “she shed”
2. American Society of Regional Anesthesia
3. ASRA anticoagulation guidelines (2018)
4. American Society of Anesthesiologists (ASA) 
5. “Anesthesia 101” from the ASA
6. Anesthesia Patient Safety Foundation 
7. The Society for Perioperative Assessment and Quality Improvement (SPAQI)

*The Curbsiders participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising commissions by linking to Amazon. Simply put, if you click on our Amazon.com links and buy something we earn a (very) small commission, yet you don’t pay any extra.

Goal

Listeners will develop an understanding of the types of care that anesthesiologists provide and how internal medicine clinicians can work with anesthesiologists and other members of the surgical team to provide the safest surgical space possible.

Learning objectives

After listening to this episode listeners will…  

1. Explore the different ways that anesthesia can be delivered and what the types of anesthesia are.

1. Discuss the intraop environment and areas that may be shrouded in mystery for the internist.
2. Discuss how anesthesiologists and internists might have different interpretations of the periop guidelines.

Disclosures

Dr. Selzer reports no relevant financial disclosures.  The Curbsiders report no relevant financial disclosures. 

Citation

Jyang E, Selzer A, O’Glasser AY, Watto MF. “#Perioperative Medicine with Anesthesiologist Dr. Angela Selzer”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list. November 11, 2022.