Podcast

Chuck Vega, MD, on Determining Site and Duration of Treatment for CABP

08/11/2021

In this podcast, Chuck Vega, MD, speaks about how clinicians determine site and duration of treatment for community-acquired bacterial pneumonia (CABP) based on patients' factors and prior treatment, including the difference in score systems used to predict the severity of CABP and the considerations for inpatient vs outpatient care. This podcast is part 2 of a 3-part series on managing CABP. 

Additional Resources:


For more information on community-acquired bacterial pneumonia, visit our CABP Resource Center. 

Chuck Vega, MD, is a clinical professor of family medicine, the assistant dean for Culture and Community Education, and the director of the Program in Medical Education for the Latino Community at the University of California, Irvine in Irvine, California.

TRANSCRIPTION:

Jessica Bard: Hello, everyone, and welcome to another installment of "Podcast360," your go‑to resource for medical news and clinical updates. I'm your moderator, Jessica Bard, with Consultant360 Specialty Network.

Pneumonia is among the leading causes of morbidity and mortality worldwide. Diagnostic and therapeutic choices are heavily dependent upon the setting in which pneumonia is acquired.

Dr Chuck Vega is here to speak with us today about community‑acquired bacterial pneumonia, CABP, and how clinicians determine site and duration of treatment based on patient's factors and prior treatment.

Dr Vega is a clinical professor of family medicine, the Assistant Dean for culture and community education, and the director of the program and medical education to the Latino community, at the University of California Irvine, in Irvine, California.

Thank you for joining us today, Dr Vega. Can you please talk to us about the difference in score systems used to predict the severity of CABP, Pneumonia Severity Index, versus CURB‑65 versus expanded CURB‑65?

Dr Chuck Vega: The inpatient versus outpatient management of CABP is one of those critical decision points, and we do get a lot of patients with pneumonia in the hospital.

In fact, there's a study that's published in 2018 that showed that per capita, the hospitalization rate for pneumonia for 100,000 persons [inaudible 1:22] in the United States was double that of myocardial infarction. It was more than three times higher than stroke. Twice plus as high as osteoporotic fracture, and associated with more costs in total as well.

It was just more common. Also associated with a higher death rate among hospitalized patients. There's a goal to reduce the overall rate of hospitalization among patients with CABP because we know that when they're hospitalized, the cost is about 25 times greater and that about 80 percent of patients actually prefer outpatient treatment.

They can return to activity faster, and therefore there's definitely some reasons to promote outpatient‑based treatment. For safety reasons, there's also good reasons to admit many patients with pneumonia.

These decision tools and these aids that have come to the fore have really helped with that difficult decision and given us some more evidence‑based guidelines so that we can manage patients and triage them appropriately to the inpatient versus outpatient treatment setting. You probably want to know about what the guidelines are. Correct?

Jessica: That's correct. That was my next question. Go for it.

Dr Vega: All right. There's really two main indexes that I've used that I'm familiar with. One is the Pneumonia Severity Index, and the other is that CURB‑65. I'll talk about ‑‑ if you're not familiar with that ‑‑ why it's called CURB in a minute. The Pneumonia Severity Index is a more straightforward title. It's easy to understand.

In the American Thoracic Society, Infectious Disease Society of America guidelines regarding the management of community‑acquired pneumonia, they recommend that Pneumonia Severity Index over CURB‑65.

I'll start with the PSI, Pneumonia Severity Index. It's something where I need to use a risk calculator, and there are risk calculators available online or through an app that are very easy to use. It does not take long. It factors in age, coexisting illnesses, findings on physical examination, and lab and X‑ray findings as well.

It is something where folks who get a score under 70 should be considered for outpatient therapy. Age itself ‑‑ I'll just point out, because I can't go into all the details of the PSI ‑‑ but age in itself for men counts as points. If you're 50 years old, that's 50 points.

For women, it's age minus 10 because men have a higher risk of complications associated with pneumonia, but say for a 70‑year‑old individual, you're already moving towards inpatient because there's going to be...and many have comorbid illnesses. Those add on 10 per illness.

I was surprised that this actually keeps a lot of patients out of the hospital. It seems like a lot of my older patients have a PSI score which puts them as inpatient status. What I think it's really good at doing is keeping our 38‑year‑olds ‑‑ maybe with one comorbid illness ‑‑ and keeps them out of the hospital because those patients many times do not need to be admitted.

That's the benefit of the PSI and it has been shown to discriminate in terms of who is at a higher risk. It has been shown, as well, to help keep patients managed as outpatients, which is better for the patient in terms of their recovery and better for our health system in terms of saving costs.

I mentioned CURB‑65 too. This is a pretty straightforward tool and what it has to do with is the CURB stands for confusion of new‑onset in patients, a blood urea nitrogen score above 19 milligrams per deciliter, respiratory rate of 30 breaths per minute or more, a blood pressure that's low ‑‑ less than 90 over 60, systolic over diastolic ‑‑ and age is 65 years or more.

If they have zero or one of those positive, you can treat as an outpatient. Two are positive, it's considered to be a short stay in the hospital or watch very closely as an outpatient. A score of three to five would indicate that they require hospitalization. It's faster to use, but it may not be quite as discriminating.

Jessica: What would constitute a complex case of CABP, and how would you manage that patient?

Dr Vega: Complex case has a lot of different potential definitions. A complex case could be somebody who's presenting with more subtle symptoms and signs where you suspect pneumonia, but you're not sure.

It can also mean somebody with more severe pneumonia or maybe somebody who took some amoxicillin they had from an infection three years ago, and they weren't doing better at day three so now they're seeing you.

There's a ton of different definitions I can think of or scenarios that would suggest a more complicated case. These are things we see all the time. In terms of severe pneumonia, there are formal criteria for that. A major criteria would include septic shock or respiratory failure. These are patients who are already in the inpatient setting.

You can have severe pneumonia without having one of those major criteria, but again this is the minor criteria. You have to have at least three of them. They would involve things like hypothermia, hypotension, tachyphemia, as well as confusion and some laboratory findings.

These are patients who are, of course, should be admitted if they're not admitted yet. Many times if they have those criteria for severe pneumonia, they need to be cared for in the ICU.

Jessica: What comorbidities are common in patients with CABP?

Dr Vega: The more comorbidities you have, the higher your risk for CABP. Those include things like diabetes, like a history of immune suppression. That could be immune‑suppressive illness. Many times it's because they're being treated, say, with a biologic agent or chronic prednisone for rheumatologic condition or for chemotherapy for cancer. Those are some of the conditions.

Then any chronic lung condition, whether it's interstitial lung disease, or COPD, asthma, heart failure, the list goes on and on.

One is, it's a call to try to treat those chronic illnesses appropriately because when the patient has exacerbation, they're more likely to get pneumonia. Two, these are folks who needed to be at high priority for prevention through vaccination in particular.

Jessica: Which medications have been used previously to treat CABP, and are new medications needed?

Dr Vega: Usually, when patients are presenting as outpatients, it's OK to use either amoxicillin or doxycycline using macrolides with caution because of the risk of pneumococcal resistance. New medications are particularly necessary more in the inpatient setting, and where we can see polymicrobial infections and with resistant organisms.

Seeing that innovation there is important because we have run into cases where it seems like no antibiotic might be effective. Instead, we have to consult infectious disease and try to work with a cocktail of different antibiotics to gain the upper hand in the fight against pneumonia.

Jessica: You mentioned polymicrobial infection. How would you manage a patient with a polymicrobial infection?

Dr Vega: In patients who don't have MRSA, Methicillin‑Resistant Staphylococcus Aureus or Pseudomonas infection, beta‑lactam plus a macrolide or respiratory fluoroquinolone can be sufficient.

When they either have known colonization or prior infection with pseudomonas, it makes more sense to use an antipseudomonal beta‑lactam, like cefepime or piperacillin‑tazobactam plus an antipseudomonal fluoroquinolones, Cipro. I prefer levofloxacin among those patients as well.

The other high‑risk group that we can see is folks with a known colonization, or prior infection with MRSA, or when we have strong suspicion of MRSA. There it's worth adding an agent with anti‑MRSA activity, that's vancomycin or linezolid. That might be a little bit preferred because it inhibits bacterial toxin production.

It's starting to reach that level of polypharmacy where you are talking about maybe three antibiotics for the same patient, rarely even four antibiotics on the same patient who's high risk with a polymicrobial infection.

Jessica: How does the treatment regimen impact the patient's journey?

Dr Vega: When we add more antibiotics, we open things up to higher risk of adverse events, whether it's a drug allergy, a drug interaction, perhaps a higher risk of selecting out for more resistant organisms. That's why it's important to try to focus in on the specific organism when you have your culture and sensitivities established to initiate therapy that is effective, but also focused on the organism at hand.

Jessica: How do clinicians determine how to de‑escalate therapy transition from broad to narrow‑spectrum therapy or choose targeted therapy?

Dr Vega: That's a great question, and that's what I was alluding to. While we start patients off on a more broad‑based regimen, as inpatients, usually by day two or three, hopefully, we have an organism that we can identify. We can now drop the more broad‑spectrum regimen and use something that's more focused on what the organism is sensitive to.

It also should be noted that for the majority of patients who are hospitalized with community‑acquired pneumonia, a causative pathogen is not identified. Therefore, that may mean that you need to continue empiric therapy for the duration, as long as the patient is getting better.

Jessica: What would you say are the risk factors for rehospitalization?

Dr Vega: Rehospitalization is certainly a big problem among patients with pneumonia, and it's a problem for hospitals. According to Medicare data, the 30‑day readmission rate for community‑acquired pneumonia is between 17 and 25 percent, depending on the study you're looking at.

Known risk factors include male sex, older age, lower educational attainment, and then there's a lot of comorbid conditions, particularly a heart failure immune deficiency that put patients at risk for rehospitalization. It's worth stepping back and thinking about the fact that a lot of cases of community‑acquired bacterial pneumonia don't resolve completely.

They may be treated with antibiotics as inpatients, but they're still coughing, they're still fatigued. About up to one in six cases fail antibiotic therapy. Therefore they're going to do worse, the symptoms shall return and stronger this time, and they end up getting readmitted to the hospital.

It's nice to focus on things we can control. Modifiable risk factors include just getting the right care, getting an appropriate regimen for pneumonia, good discharge planning.

Particularly with regards to following up and making sure that they have outpatient follow‑up and trying to remove those barriers to either getting their medications as outpatients, to making sure they have prompt follow‑up so that any issues can be identified, hopefully with their primary care clinician.

Those are things we can do to drive down readmission rates for these patients with CABP.

Jessica: Is there anything else you'd like to add today about how clinicians determine site and duration of treatment?

Dr Vega: No, I think that we tend to overuse antibiotics. For some patients, a five‑day course is perfectly reasonable. For most of my patients, I'm giving seven days.

As I mentioned, for patients with more severe pneumonia or have more comorbidities, 10‑day course of therapy what's usually what's required. You can follow these patients as outpatients to make sure that they are doing better. As long as they are improving, I feel comfortable stopping antibiotics at those specified times.

Jessica: Thank you so much for joining us today, Dr Vega. We appreciate your time.

Dr Vega: I appreciate being here. Thanks. Thanks to you.