Chest Radiographs May Be Overused in Severe Pneumonia

CHICAGO — Routine follow-up chest radiography may not be appropriate for patients with severe community-acquired pneumonia who clinically respond to initial antibiotic therapy, according to a multicenter study presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy.

“In addition, chest radiographs obtained prior to hospital discharge, as advised by the American Thoracic Society in their 1993 guideline, seem to be unnecessary,” according to the authors, whose study was published shortly after the conference (Clin. Infect. Dis. 2007;45:983–91).

The use of follow-up chest x-rays of patients hospitalized for severe community-acquired pneumonia (CAP) has become common clinical practice, and the absence of guidelines leaves physicians reliant on recommendations derived from grade D evidence, said lead author and presenter Dr. Anke H.W. Bruns, a research fellow in the department of internal medicine and infectious diseases at the University Medical Center Utrecht (the Netherlands).

“Furthermore, the timing of those follow-up chest x-rays is difficult, in part because we know little about time-to-resolution of findings related to infection on a film,” she said. “So, follow-up radiographs probably are ordered unnecessarily.”

To address this question, the researchers studied 288 patients enrolled between July 2000 and June 2003 from a prospective randomized trial on the cost-effectiveness of an early switch from parenteral to oral therapy for severe CAP.

The mean age of the patients was 70 years, and two-thirds were men. The mean pneumonia severity index at admission was 113, half the patients had comorbidities, and virtually all patients had been placed on a β-lactam (82%) or β-lactam-macrolide combination (14%).

Of the 140 cases with proven microbiological etiology, 44% had Streptococcus pneumoniae. Another 20% had atypical pathogens, including Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. The remaining 36% were infected with unidentified pathogens, Dr. Bruns explained.

Patients were observed for a maximum of 28 days, and those who were still hospitalized on day 7 underwent follow-up chest radiography. After hospital discharge, all patients were asked to return to the outpatient clinic for clinical evaluation, blood chemistry analysis, and a chest radiograph at day 28. Scores for clinical improvement on day 7 and for clinical cure on day 28 were calculated for each patient. The cumulative dropout rate for radiographs was 21% at day 7 and 32% at day 28.

Radiologists reviewed the radiographs for the presence of pulmonary infiltrates, pleural fluid, atelectasis, pulmonary edema, and other findings. During follow-up, clearance of pulmonary infiltrates and resolution of chest radiograph abnormalities were established.

At 1 week, 33% of patients had clearance of pulmonary infiltrates, and only 25% demonstrated resolution of chest radiograph abnormalities. At 1 month, 62% of patients had clearance of infiltrates, and 53% had resolution of radiograph abnormalities. Resolution occurred more slowly in patients with proven S. pneumoniae pneumonia, the investigators reported.

Resolution of radiograph abnormalities lagged behind clinical improvement: At 1 week, clinical improvement was observed in more than half of patients, while resolution of chest radiograph abnormalities was seen in only one-quarter of patients. At 1 month, 78% of patients had clinical cures, and 53% showed resolution on radiographs.

The patients with radiographic deterioration were compared with those without radiographic deterioration for outcomes that included clinical cure at 1 month, mortality, and intervention during follow-up. “We saw no difference in any of those three parameters, so we can state that chest radiograph deterioration during follow-up was not associated with poor outcome,” Dr. Bruns said at the conference sponsored by the American Society for Microbiology.

Clinical parameters that independently predicted delayed resolution of chest radiograph findings at 1 week included dullness to percussion, multilobar disease, high respiratory rate, and high C-reactive protein (CRP) level. CRP level greater than 200 mg/L at admission also predicted delayed resolution of chest radiograph abnormalities at day 28.

The authors noted that the number of interventions in patients with deterioration of chest radiograph findings was comparable to the number of interventions in other patients, suggesting that physicians' decisions were not made solely on the basis of chest radiograph findings.

“Performing a chest x-ray to exclude a noninfectious cause of pneumonia within 4 weeks of initial diagnosis is not indicated, because at this point half of patients have radiographic findings that are a result of normal clinical course and do not necessarily indicate pathology,” Dr. Bruns said.

“Chest radiograph deterioration during follow-up was not associated with poor outcome, so in our opinion, routine in-hospital follow-up radiographs in severe CAP have no additional value,” she said.

CHICAGO — Routine follow-up chest radiography may not be appropriate for patients with severe community-acquired pneumonia who clinically respond to initial antibiotic therapy, according to a multicenter study presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy.

“In addition, chest radiographs obtained prior to hospital discharge, as advised by the American Thoracic Society in their 1993 guideline, seem to be unnecessary,” according to the authors, whose study was published shortly after the conference (Clin. Infect. Dis. 2007;45:983–91).

The use of follow-up chest x-rays of patients hospitalized for severe community-acquired pneumonia (CAP) has become common clinical practice, and the absence of guidelines leaves physicians reliant on recommendations derived from grade D evidence, said lead author and presenter Dr. Anke H.W. Bruns, a research fellow in the department of internal medicine and infectious diseases at the University Medical Center Utrecht (the Netherlands).

“Furthermore, the timing of those follow-up chest x-rays is difficult, in part because we know little about time-to-resolution of findings related to infection on a film,” she said. “So, follow-up radiographs probably are ordered unnecessarily.”

To address this question, the researchers studied 288 patients enrolled between July 2000 and June 2003 from a prospective randomized trial on the cost-effectiveness of an early switch from parenteral to oral therapy for severe CAP.

The mean age of the patients was 70 years, and two-thirds were men. The mean pneumonia severity index at admission was 113, half the patients had comorbidities, and virtually all patients had been placed on a β-lactam (82%) or β-lactam-macrolide combination (14%).

Of the 140 cases with proven microbiological etiology, 44% had Streptococcus pneumoniae. Another 20% had atypical pathogens, including Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. The remaining 36% were infected with unidentified pathogens, Dr. Bruns explained.

Patients were observed for a maximum of 28 days, and those who were still hospitalized on day 7 underwent follow-up chest radiography. After hospital discharge, all patients were asked to return to the outpatient clinic for clinical evaluation, blood chemistry analysis, and a chest radiograph at day 28. Scores for clinical improvement on day 7 and for clinical cure on day 28 were calculated for each patient. The cumulative dropout rate for radiographs was 21% at day 7 and 32% at day 28.

Radiologists reviewed the radiographs for the presence of pulmonary infiltrates, pleural fluid, atelectasis, pulmonary edema, and other findings. During follow-up, clearance of pulmonary infiltrates and resolution of chest radiograph abnormalities were established.

At 1 week, 33% of patients had clearance of pulmonary infiltrates, and only 25% demonstrated resolution of chest radiograph abnormalities. At 1 month, 62% of patients had clearance of infiltrates, and 53% had resolution of radiograph abnormalities. Resolution occurred more slowly in patients with proven S. pneumoniae pneumonia, the investigators reported.

Resolution of radiograph abnormalities lagged behind clinical improvement: At 1 week, clinical improvement was observed in more than half of patients, while resolution of chest radiograph abnormalities was seen in only one-quarter of patients. At 1 month, 78% of patients had clinical cures, and 53% showed resolution on radiographs.

The patients with radiographic deterioration were compared with those without radiographic deterioration for outcomes that included clinical cure at 1 month, mortality, and intervention during follow-up. “We saw no difference in any of those three parameters, so we can state that chest radiograph deterioration during follow-up was not associated with poor outcome,” Dr. Bruns said at the conference sponsored by the American Society for Microbiology.

Clinical parameters that independently predicted delayed resolution of chest radiograph findings at 1 week included dullness to percussion, multilobar disease, high respiratory rate, and high C-reactive protein (CRP) level. CRP level greater than 200 mg/L at admission also predicted delayed resolution of chest radiograph abnormalities at day 28.

The authors noted that the number of interventions in patients with deterioration of chest radiograph findings was comparable to the number of interventions in other patients, suggesting that physicians' decisions were not made solely on the basis of chest radiograph findings.

“Performing a chest x-ray to exclude a noninfectious cause of pneumonia within 4 weeks of initial diagnosis is not indicated, because at this point half of patients have radiographic findings that are a result of normal clinical course and do not necessarily indicate pathology,” Dr. Bruns said.

“Chest radiograph deterioration during follow-up was not associated with poor outcome, so in our opinion, routine in-hospital follow-up radiographs in severe CAP have no additional value,” she said.

CHICAGO — Routine follow-up chest radiography may not be appropriate for patients with severe community-acquired pneumonia who clinically respond to initial antibiotic therapy, according to a multicenter study presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy.

“In addition, chest radiographs obtained prior to hospital discharge, as advised by the American Thoracic Society in their 1993 guideline, seem to be unnecessary,” according to the authors, whose study was published shortly after the conference (Clin. Infect. Dis. 2007;45:983–91).

The use of follow-up chest x-rays of patients hospitalized for severe community-acquired pneumonia (CAP) has become common clinical practice, and the absence of guidelines leaves physicians reliant on recommendations derived from grade D evidence, said lead author and presenter Dr. Anke H.W. Bruns, a research fellow in the department of internal medicine and infectious diseases at the University Medical Center Utrecht (the Netherlands).

“Furthermore, the timing of those follow-up chest x-rays is difficult, in part because we know little about time-to-resolution of findings related to infection on a film,” she said. “So, follow-up radiographs probably are ordered unnecessarily.”

To address this question, the researchers studied 288 patients enrolled between July 2000 and June 2003 from a prospective randomized trial on the cost-effectiveness of an early switch from parenteral to oral therapy for severe CAP.

The mean age of the patients was 70 years, and two-thirds were men. The mean pneumonia severity index at admission was 113, half the patients had comorbidities, and virtually all patients had been placed on a β-lactam (82%) or β-lactam-macrolide combination (14%).

Of the 140 cases with proven microbiological etiology, 44% had Streptococcus pneumoniae. Another 20% had atypical pathogens, including Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. The remaining 36% were infected with unidentified pathogens, Dr. Bruns explained.

Patients were observed for a maximum of 28 days, and those who were still hospitalized on day 7 underwent follow-up chest radiography. After hospital discharge, all patients were asked to return to the outpatient clinic for clinical evaluation, blood chemistry analysis, and a chest radiograph at day 28. Scores for clinical improvement on day 7 and for clinical cure on day 28 were calculated for each patient. The cumulative dropout rate for radiographs was 21% at day 7 and 32% at day 28.

Radiologists reviewed the radiographs for the presence of pulmonary infiltrates, pleural fluid, atelectasis, pulmonary edema, and other findings. During follow-up, clearance of pulmonary infiltrates and resolution of chest radiograph abnormalities were established.

At 1 week, 33% of patients had clearance of pulmonary infiltrates, and only 25% demonstrated resolution of chest radiograph abnormalities. At 1 month, 62% of patients had clearance of infiltrates, and 53% had resolution of radiograph abnormalities. Resolution occurred more slowly in patients with proven S. pneumoniae pneumonia, the investigators reported.

Resolution of radiograph abnormalities lagged behind clinical improvement: At 1 week, clinical improvement was observed in more than half of patients, while resolution of chest radiograph abnormalities was seen in only one-quarter of patients. At 1 month, 78% of patients had clinical cures, and 53% showed resolution on radiographs.

The patients with radiographic deterioration were compared with those without radiographic deterioration for outcomes that included clinical cure at 1 month, mortality, and intervention during follow-up. “We saw no difference in any of those three parameters, so we can state that chest radiograph deterioration during follow-up was not associated with poor outcome,” Dr. Bruns said at the conference sponsored by the American Society for Microbiology.

Clinical parameters that independently predicted delayed resolution of chest radiograph findings at 1 week included dullness to percussion, multilobar disease, high respiratory rate, and high C-reactive protein (CRP) level. CRP level greater than 200 mg/L at admission also predicted delayed resolution of chest radiograph abnormalities at day 28.

The authors noted that the number of interventions in patients with deterioration of chest radiograph findings was comparable to the number of interventions in other patients, suggesting that physicians' decisions were not made solely on the basis of chest radiograph findings.

“Performing a chest x-ray to exclude a noninfectious cause of pneumonia within 4 weeks of initial diagnosis is not indicated, because at this point half of patients have radiographic findings that are a result of normal clinical course and do not necessarily indicate pathology,” Dr. Bruns said.

“Chest radiograph deterioration during follow-up was not associated with poor outcome, so in our opinion, routine in-hospital follow-up radiographs in severe CAP have no additional value,” she said.