Risk Assessment and Mitigation of Perioperative Pulmonary Complications (Podcast)

“Surprisingly, pulmonary complications are more common than cardiac complications,” says Preethi Patel, MD, on a recent podcast episode of Respiratory Exchange. “So, I think it becomes important for us to check every patient, or at least assess them, for any sort of preexisting pulmonary condition or mitigating factors that we may have in the pre-op setting. And, just to put things in context, there are about 150,000 cardiac complications that we record every year and a million pulmonary complications.”

Given their frequency, it is especially important for clinicians to take steps to reduce risk by evaluating the patient, procedure and anesthesia plan together. This involves optimizing modifiable factors before surgery and individualizing care throughout the perioperative period.

One of the challenges when it comes to management, according to Dr. Patel, is that unlike cardiac complications, which are clear and well-defined, pulmonary complications are not.

“In the pulmonary realm, anything from post-op hypoxia where you're requiring oxygen for a longer duration than you would use versus ARDS and requiring intubation, reintubation, pneumonia, atelectasis — these are some of the very, very common complications we encounter,” she says.

But even complications that appear relatively minor can have lasting consequences. Dr. Patel notes that research associates the lowest-grade pulmonary complications with increased 30-day mortality, reinforcing the importance of identifying and mitigating risk before surgery.

Several patient and procedure factors are important to consider when doing an assessment. These include patient age, frailty, mobility level, underlying pulmonary disease and recent respiratory infection, which can elevate risk. The location, duration and type of surgery can also increase risk. For example, upper abdominal and cardiothoracic procedures carry particularly high pulmonary risk, while longer operations and general anesthesia can also add to it.

Assessing pulmonary risk

In the episode, Dr. Patel outlines some risk mitigation strategies, including STOP-BANG and ARISCTAT.

“We assess everybody for sleep apnea, especially patients with obesity or with history of poor sleep hygiene, etc.,” she explains. “We also do a STOP-BANG score with everybody; it has very good sensitivity and very good negative predictive value to determine especially severe sleep apnea in the pre-op setting. ARISCAT scoring is our tool of choice in our pre-op clinic.”

Mitigating modifiable risk

When risk factors are identified, clinicians should try to modify what can be modified. This includes optimizing COPD and asthma, delaying surgery after infection when appropriate and considering anesthesia alternatives.

For patients with nonmodifiable risk factors, the goal is to tailor the surgical and anesthesia plan through shared decision-making.

“The whole idea of the pre-op clinic is to bring everybody together and say, ‘This patient is high risk. How can we mitigate some of that risk? Can we do a shorter surgery? Can we avoid general anesthesia or neuromuscular blockade? Do they have pulmonary hypertension that we need to assess?’” Dr. Patel says. “Unfortunately, a lot of these factors are not modifiable.”

In the excerpt below, Dr. Patel explains how she approaches patients with active wheezing or uncontrolled COPD, when preoperative steroids may be appropriate and why clinical judgment matters more than a single numerical cutoff.

Listen to the full episode by clicking the podcast player above, or find more Respiratory Exchange episodes here or wherever you get your podcasts.

Excerpt

Dan Culver, DO (episode host): So, you're really looking at number one, raising awareness and everybody being above board about what's happening before surgery, modifying the modifiable and then having a direct discussion across the team about the benefits of the surgery and how to proceed. One of the things that has come up sometimes and perhaps it's a bit in the rear-view mirror now, but people still ask about giving a course of steroids in patients with COPD before surgery to cut down on mucus secretion or to help control wheezing. What do you do in your practice?

Dr. Patel: If the patient is actively wheezing, especially if it's a patient with uncontrolled COPD at baseline requiring multiple courses of rescue inhalers, we definitely do a short course of steroids, and there's very good data to say that really does not harm patient outcomes in any way. In fact, it may be beneficial. There's one thing about adrenal insufficiency, and these are patients who have really severe COPD who are on multiple courses of steroids over the years. Those are the patients we worry about, but again, if you think about it, we can fix it. But preemptively giving steroids to a patient who has well-controlled disease, that's not something that's necessary or is advisable.

Dr. Culver: Do you have any numbers that you use? You mentioned some of the tests, but do you have some specific cutoffs that you use to either decide to escalate treatment or where you would call up the surgeon or the anesthesiologist and say, "I'm not happy with what I see here?"

Dr. Patel: We don't routinely do bedside spirometry in the clinic. We look at the spirometry data, and we look to see patients who are really high risk and have high COPD or GOLD classification is extremely high, and patients have severe COPD. In those patients, we are basically looking at what their underlying baseline medical treatment is like, whether that is optimized or not. There are other things like VO2 max. There are other things like six-minute walk tests, but none of them have been validated or proven to say, "Okay, these are the numbers we're going to use where we're going to be treating." So, it's completely clinical decision-making at the time that we're seeing the patient.

Dr. Culver: I suppose oxygen requirement and the presence of hypercapnia are important.

Dr. Patel: Yeah. So those are important, and we see patients who have baseline hypercapnia to begin with. They have compensation. So, if you notice that they're going into the decompensated stage, those are the patients we don't want to send for elective surgery in any way.