Published in the November 2007 issue of Today’s Hospitalist
When it comes to caring for patients with community-acquired pneumonia (CAP), one of the nation’s top hospitalist experts on the disease is calling on hospitalists to change some of the strategies they have used for years.
Based on recent evidence, Scott A. Flanders, MD, associate professor at the University of Michigan and director of its hospitalist program, says it’s time for hospitalists to start some new treatments. That change is due in part to the spread of methicillin-resistant Staphylococcus aureus (MRSA) and to new thinking about health-care acquired pneumonia.
But he is quick to add that hospitalists should also stop some traditional care, including long courses of antibiotics and blood cultures for all. And he urges colleagues to consider using some different approaches.
During his presentation at the Spring 2007 Hospitalist CME Series held earlier this year in Cambridge, Mass., Dr. Flanders said that despite plenty of research “more than 500 articles were published on CAP in the last year alone “management of the disease hasn’t improved substantially in the last 20years.
The rate of suffering from a comorbid disease has increased in that period from 66% to 77%, and the risk of dying of the disease in the hospital has not changed at all.
CAP remains the most frequent discharge diagnosis in the U.S., with 1 million hospitalizations per year (out of between 5 million and 6 million cases). To get an idea of CAP’s magnitude, consider the following statistic: The risk of death for pneumonia is still 50% greater than for the 10 next most common diagnoses. “A lot of work remains to be done,” Dr. Flanders explained.
The value of chest X-rays
When diagnosing CAP, the chest X-ray is the first test that physicians think of. But Dr. Flanders explained that chest films are a weak diagnostic tool at best.
“CAP may exist when the chest X-ray is negative,” he explained. Studies show that findings tend to be “equivocal” in 30% of cases. If the patient has comorbid chronic obstructive pulmonary disease (COPD), Dr. Flanders added, agreement among radiologists is “horrible.”
And while physicians probably order too many chest X-rays, they tend to ignore results when planning treatment. He pointed to an August 2004 study in Clinical Radiology that found that although radiologists said 15%of the patients they were looking at had CAP, doctors treated 80%.
New diagnostic imaging techniques
While physicians’ diagnostic arsenal may be limited, Dr. Flanders urged colleagues to start or consider using some new diagnostic methods that should help them tailor drug therapy. While sputum testing has been out of favor for years, he said hospitalists should use this strategy for a select group of patients “namely, those in the ICU or those for whom MRSA is a concern.
And because blood cultures should be done only for targeted populations, Dr. Flanders urged hospitalists to stop culturing everybody. “Less than 5% of blood cultures lead to any meaningful change in therapy,” he explained.
Instead, he said, culture only those patients with risk factors “which include liver disease, previous antibiotic exposure, or worrisome vital signs, including pulse, blood pressure, white blood cells, temperature and BUN “to detect most cases of bacteremia. This strategy of selective culturing produces 40% fewer cultures, he said.
Targeted therapies
Physicians are rarely able to identify the cause of community-acquired pneumonia, and there is yet no reliable method to predict when the illness is being caused by an atypical agent. As a result, physicians tend to rely on empiric therapy with a broad-spectrum antibiotic. But that strategy is increasing the incidence of multidrug-resistant organisms and driving the nationwide spread of community-associated MRSA-caused pneumonia.
For the most part, Dr. Flanders said, the antibiotics used to treat CAP empirically “are not effective against community-acquired MRSA. A lot of things are making us rethink the strategy of ‘just give them antibiotics and don’t worry about what’s causing the infection.’ ”
The good news is that work is underway on promising new tests, like a urinary antigen test for pneumococcus.
Studies to date have shown that although the sensitivity of the urinary antigen test is not great, if does offer good specificity. “If it is positive, that is highly suggestive that the patient has pneumococcus,” Dr. Flanders said. Physicians can then target therapy, avoiding additional diagnostic testing and unnecessary antibiotics.
Although new guidelines have endorsed the urinary antigen test, particularly in ICU patients, the data so far only support targeted therapy “which the test could help facilitate “in less severely ill patients. “But it’s very promising,” Dr. Flanders said, “and I think something that is working its way into the standard of care.”
Unusual organisms
When considering unusual organisms, Dr. Flanders said he uses the “4As”: aspiration, prior admission, prior antibiotics, and advanced pulmonary comorbidity illness. Studies show that if a patient has three of these, the odds ratio of having a gram negative organism is 40.
Because having COPD is the most common predictor of which patients will have a pseudomonas infection, Dr. Flanders recommended that hospitalists start adding anti-pseudomonal coverage when treating CAP in COPD patients in the ICU. One study found that 75% of ICU patients with pseudomonas were receiving “inappropriate therapy, mainly because the doctors were not giving patients with bad COPD pseudomonal treatment,” he explained.
Another clue to help target treatment is recognizing when pneumonia patients do not truly acquire their illness in the “community,” but have been in contact with nursing homes, dialysis centers, outpatient clinics for IV therapy, and home health care, or have been previously hospitalized in the last 90 days. These patients are now thought to have health-care associated pneumonia, and their infections are more likely to include S. aureus, MRSA and pseudomonas.
“They look a lot more like the hospital-acquired pneumonia and ventilator-associated pneumonia groups,” Dr. Flanders said. Hospitalists should start treating health care-associated pneumonia just like they would nosocomial pneumonia, he explained.
The admission decision
Two of the most complicated decisions hospitalists make when treating CAP are which patients to send home and how soon hospitalized patients can be discharged. Dr. Flanders pointed out that many problems with subsequent infections and other treatment side effects can be avoided with earlier discharge or alternative treatment sites.
Despite the existence of well-tested tools that physicians should use to determine whether a CAP patient needs hospitalization, Dr. Flanders said, studies still find that nearly one-half of patients in the lowest risk classes still get admitted. In a fifth of these cases, medical records show “no clear indication for admission.”
One tool he recommended is the Pneumonia Severity Index (PSI). Patients in risk classes 1-3 of the PSI are generally considered at low risk, while those in classes 4 and 5 are considered at high risk of mortality and rehospitalization. (A calculator is available online.)
An even easier tool to use to help decide which CAP patients need hospitalization is CURB-65, which stands for confusion, uremia, respiratory rate, low blood pressure, and age 65 or greater. It was recommended in the 2007 consensus guidelines from the Infectious Diseases Society of America and the American Thoracic Society on CAP management. (The new guideline is available
online.)
For hospitalized patients, the evidence indicates that physicians need to explore heart failure, pulmonary embolism and other possibilities before rushing to prescribe antibiotics.
Hospitals are still required to report that they have given antibiotics to CAP patients within four hours. But ED physicians increasingly point out that as many as 20% of pneumonia patients have unusual presentations.
According to Dr. Flanders, the Centers for Medicare and Medicaid Services is now considering a six-hour window for prescribing antibiotics to these patients instead. The fact remains, he added, that many hospitals don’t prescribe antibiotics within four hours because so many patients are hard to diagnose.
Drug resistance
When choosing antibiotic therapy, Dr. Flanders said, hospitalists need to consider resistance. Because so much CAP is caused by pneumococcus (S. pneumoniae), the first issue to deal with is the dramatic increase in the rates of penicillin-resistant pneumococcus.
As of 2003, he explained, about 30% of all isolates demonstrated some level of resistance. About one-half of those showed high-level resistance.
Patients with a resistant bug are likely to be sicker, Dr. Flanders said. But the good news is that penicillin-resistant pneumococcus, by itself, “is not associated with increased risk of a bad treatment outcome when treated with a beta-lactam, for the most part.”
He recommended that physicians stop using two drugs after they identify that the bug causing the pneumonia is S. pneumoniae.
Another class of drugs to avoid with all patients who used them as an outpatient, Dr. Flanders said, is macrolides. Macrolide resistance has reached about 35% nationwide and is a particular problem with patients who are older and coming from nursing homes. “A macrolide should probably not be one of the drugs you use in that initial empiric therapy.”
Concerning fluoroquinolones, the resistance that occurs with CAP is usually in COPD patients who have been treated with many cycles of fluoroquinolones.
Combination therapy
Critically ill CAP patients, especially those with recent influenza or who live in communities with a lot of MRSA, should receive vancomycin, Dr. Flanders said.
“There are not big randomized controlled trials that tell us exactly what to treat patients with,” he noted. Data have shown, however, that combination therapy “a beta-lactam plus a macrolide “is associated with less mortality than monotherapy.
The problem with combination therapy, however, is that although two drugs may be better than one for very sick bacterimic patients, they probably don’t need to be given for the duration of the treatment. Instead, physicians should tailor drug regimens as they learn more about etiology.
In terms of adjuvant therapy, some experts think that giving steroids along with antibiotics to “patients with severe pneumonia” can help. A recent study showed that the strategy holds promise, but questions remain, Dr. Flanders said.
Nonetheless, he added, it may be worth considering giving steroids to CAP patients who are sick enough to be in the ICU, based on the results of an ACTH stimulation test of cortisol levels.
Deborah Gesensway is a freelance writer reporting on U.S. health care from Toronto, Canada.
Procalcitonin: a new diagnostic gold standard?
In terms of diagnosing community-acquired pneumonia (CAP), a chest X-ray has traditionally been considered the gold standard. But one-third of patients with CAP will actually look normal on a chest X-ray, and getting good information is even chancier if the patient also suffers from COPD.
As a result, pneumonia experts want a better way to determine whether sick patients have “an antibiotic-responsive illness that is causing their respiratory infections,” explained Scott A. Flanders, MD, associate professor at the University of Michigan and director of its hospitalist program.
The method that now seems most promising “although one “not ready for prime time,” he said “is measuring procalcitonin (PCT) as a marker of systemic inflammatory response to infections. Bacteria, much more than viruses or other organisms, seem to affect blood serum procalcitonin levels.
A 2006 study in Intensive Care Medicine showed that procalcitonin levels tracked with ICU prognosis. Other studies have shown that more severely ill pneumonia patients have higher procalcitonin levels than those in lower severity index classes.
Questions remain, however, about what high, low and mid-range PCT levels mean in terms of predicting the likelihood of bacterial infection, and about how levels change over the course of a hospitalization.
Researchers in Switzerland, Dr. Flanders said, have begun to look at what happens when you manage inpatients based on their PCT levels. They found that if patients with low PCT levels weren’t given antibiotics at all “or had their antibiotics stopped when PCT levels dropped throughout their hospital stay “there was no difference in terms of outcome.
“The suggestion is that you could reduce antibiotic use and get people out of the hospital faster” if procalcitonin levels were used to help make antibiotic treatment decisions, Dr. Flanders said. More trials are clearly needed of more heterogeneous inpatient populations, he said, but his take on this research is that procalcitonin is “very promising.”
Changing how you treat CAP
Hospitalist Scott A. Flanders, MD, is one of the nation’s top experts on community-acquired pneumonia. He recommends that hospitalists change some of the strategies they have used for years to treat the disease.
Here is his list of therapies to start, stop and consider.
-
Start
- adding vancomycin for critically ill CAP patients;
- sending sputums for ICU patients for whom MRSA is a concern;
- treating health care-acquired pneumonia just like nosocomial pneumonia; and
- adding anti-pseudomonal coverage to CAP patients with COPD in the ICU.
Stop
- ordering blood cultures in all CAP patients;
- using macrolides in patients who used them as outpatients;
- giving antibiotics in less than four hours to everyone who walks past the ER;
- using two drugs after S. pneumoniae is identified;
- observing patients after a switch to oral therapy;
- treating CAP for more than one week; and
- giving unnecessary proton pump inhibitors, which increase the risk of pneumonia.
Consider
- that CAP may still be present even with a negative chest X-ray;
- alternative sites for caring for non-critically ill patients;
- urinary antigen testing (and beta-lactam monotherapy), especially in young non-critically ill patients;
- steroids for CAP in the ICU if low cortisol is < 15 g/dL or ACTH stimulation test is < 9 g/dL; and
- stopping antibiotics in patients who have improved and are afebrile and tolerating orals.
