EDITORIAL

Inter-observer Reliability ofRadiologists’ Interpretation of MobileChest Radiographs for Nursing Home–Acquired Pneumonia

Paul J. Drinka, MD, CMD

An Infectious Disease Society guideline regarding infectionin long-term care facilities states that no studies demonstrateimproved outcomes related to chest radiographs to diagnosepneumonia. “However, because pneumonia is the only infec-tion that is an important contributor to mortality, it is im-portant to document this serious condition by chest radiog-raphy whenever possible.”1 The study of Loeb et al,2 entitled“Inter-observer reliability of radiologists’ interpretation of mo-bile chest radiographs for nursing home–acquired pneumonia(p. 646),” provides data that relate to this issue.

The authors studied portable chest x-rays from residentshaving at least 2 of the following: new or increased cough,sputum, or findings on chest examination; pleuritic chestpain; or temperature higher than 100.4°F. The authors con-clude that “inter-rater agreement among radiologists for mo-bile chest radiographs in establishing the presence or absenceof infiltrate can be judged to be fair.” Infectious infiltratesmust be differentiated from pulmonary collapse, infarction,edema (congestive heart failure), hemorrhage, neoplasm, drugreaction, or vasculitis. The investigators did not provide datadifferentiating the level of agreement on films with definiteversus possible infiltrate. A quick read of the paper could leadthe practitioner to forego portable chest x-rays because ofquestionable reliability. However, the authors’ literature re-view indicates that the reliability in this study was comparableto standard chest x-rays, a diagnostic test that few wouldforego in a resident wishing life-prolonging, therapeutic in-tervention. Finally, the authors note that the sensitivity ofstandard chest radiographs was only 70% compared to high-resolution computed tomography (CT) scans in the detectionof community-acquired pneumonia.3 (In this study there were

Wisconsin Veterans Home, King, WI; University of Wisconsin-Madison; Medi-cal College of Wisconsin, Milwaukee, WI.

Address correspondence to Paul J. Drinka, Wisconsin Veterans Home, N2665County Road QQ, MH 113, King, WI 54946-0620. E-mail: Paul.Drinka@dva.state.wi.us

Copyright ©2006 American Medical Directors Association

DOI: 10.1016/j.jamda.2006.02.010

EDITORIAL

no false-positive chest x-rays.3) An honest level of uncer-tainty regarding the existence of an infiltrate is far preferableto mistaken certainty. Perhaps we should use the term “chestinfection” rather than referring to those with negative chestx-rays as having “bronchitis” so that we maintain a suitablelevel of vigilance.

Administering antibiotics for chest infections in nursinghome residents without chest x-rays is an acceptable practice.The Society of Healthcare Epidemiology of America estab-lished minimum criteria for initiating antibiotics: If the resi-dent has a temperature of 102°F or higher, criteria include oneof the following: respiratory rate higher than 25 or productivecough. If the resident has a temperature of 100°F or higher,criteria include cough and one of the following: (1) pulsehigher than 100, (2) delirium, (3) shaking chills, or (4)respiratory rate more than 25. For afebrile residents withchronic obstructive pulmonary disease (COPD), criteria in-clude increased cough with purulent sputum. For afebrileresidents without COPD, criteria include new cough withpurulent sputum and one of the following: respiratory ratemore than 25 breaths or delirium.4

The portable technique is challenging in residents withdementia and/or delirium who are unable to cooperate. Move-ment, poor inspiration, and positioning difficulty lead to blur-ring and crowding of vascular markings that give the impres-sion of opacities, as well as rotation leading to unfamiliarsuperimposed densities. Films may be under- or over-pene-trated in obese or cachectic residents. There is no opportunityfor the technician to review film quality before submission tothe radiologist. Anterior-posterior (AP) views make the heartappear larger.

The interpretation of superimposed densities is especiallychallenging without the lateral view.3 Radiologists alwaysprefer 2 perpendicular views. We previously determined thevalue of the sitting lateral chest x-ray beyond that of the APfilm in 98 residents with acute chest disease. In 15 residents,the lateral film provided more precise localization or helpedclarify the nature of the abnormality such as pleural fluid

versus scarring, or prominent vessels, linear atelectasis versus

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infiltrate. In 5 residents, abnormalities were seen only on thelateral film including pleural effusions in 3, retrocardiac den-sity in 1, and nodule in 1. Pleural effusion is usually visible onlateral films before AP films.5 The finding of a pleural effusionwould be especially significant in a resident with persistentfever, despite appropriate antimicrobial therapy. In these res-idents, the need to drain empyema fluid should beconsidered.6

Pneumonia often presents as a nonspecific functional orintellectual decline with delayed diagnosis.7 In many facil-ities, residents with pneumonia who do not receive emer-gency room or hospital evaluation are handled over thetelephone following an on-site assessment by nursing staff.Antibiotics are prescribed empirically by on-call physicianswithout reviewing problem lists, medications, or recent laband x-ray reports. Follow-up may be haphazard by rotatingnursing staff. Within the context of such standard care, theportable chest x-ray probably stands as a beacon of reliabil-ity. We want to avoid shining a critical spotlight on asingle aspect of the process without measuring the reliabil-ity of the rest of the process. It is unfortunate that wecannot examine the reliability of portable chest x-rayswithin the context of the entire protocol devised by theseexpert clinicians (Loeb et al2) for the assessment andmanagement of pneumonia in the nursing home. Moreimportant than the decision to obtain a portable chestx-ray is the quality of initial clinical assessment, treatment,and follow-up.

Keep in mind that if the resident was hospitalized, he orshe would receive a complete history and physical, a 2-viewchest x-ray, admission laboratory determinations, and dailyphysician visits. Medical directors should develop focused,yet comprehensive, assessment and follow-up protocols forthe care of residents with chest infections managed in thenursing home. Initial assessment should include hydrationstatus and a careful review of current medications such asdiuretics (whose dose may be inappropriate in the setting ofdecreased intake) and sedatives/tranquilizers (which mayinterfere with pharyngeal coordination), as well as medi-cations that increase gastroesophageal reflux with aspira-tion potential.

Initial assessment could also include oximetry and brainnaturetic peptide. Left ventricular failure may coexist withpulmonary infection. BNP values between 100 and 500pg/mL may be seen in elderly individuals with pulmonaryhypertension and cor pulmonale from pulmonary paren-chymal disease, hypoxia, and/or pulmonary emboli, espe-cially with critical illness and renal compromise.8 Ray et al9

studied 202 elderly patients with a mean age of 80 yearswho presented to an emergency room with acute dyspnea�2 weeks duration. The best BNP threshold value fordifferentiating cardiac from pulmonary edema in patientsaged 65 years or older. A comprehensive assessment shouldalso be performed within 3 days of initiating antimicrobialswith an eye on discontinuing antibiotics in those withrapidly resolving aspiration events, or broadening antibi-otic coverage and intensifying treatment for those who are

failing.10 –12

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Failure to respond may be caused by ongoing aspiration(pharyngeal, gastroesophageal reflux disease), a necrotizingprocess, abscess, empyema, bronchial obstruction, tubercu-losis, or fungi. Empirically chosen regimes may not covermethicillin-resistant Staphylococcus aureus (MRSA) and an-tibiotic-resistant, gram-negative rods including Pseudomonas.Clinicians may not be aware of the guidelines for the treat-ment of health care–associated pneumonia developed by theAmerican Thoracic Society (ATS) and Infectious DiseaseSociety of America (IDSA) published in 2005.12 This guide-line, primarily developed for the care of hospitalized patientsby intensivists and infectious disease specialists, defines pneu-monia acquired in the nursing home as “health care–associated,” not “community-acquired.” Recommended em-piric coverage includes Pseudomonas aeruginosa and methicil-lin-resistant Staphlococcus aureus, especially in a facility whereresistant pathogens are endemic and/or in the presence ofindividual risk factors for multi-drug resistant organisms.12,13

Optimally, broad spectrum initial empiric coverage should bede-escalating based on cultures and the clinical response.

We are grateful to the authors for reminding us that anegative chest x-ray doesn’t get us, or the resident, “off thehook” regarding a serious pulmonary condition. As recom-mended by Loeb et al,2 I would encourage radiologists toinclude an assessment of film quality, as well as degree ofcertainty about the presence of infiltration (ie, “possible,”“probable,” or “definite”). Don’t let a false-negative chestx-ray turn your eyes away from positive clinical findings.

Let’s face it, the overlapping shadows of a poorly posi-tioned, under-penetrated AP radiograph probably have a sim-ilar reliability to some of the assessments we receive over thetelephone. I believe our first priority is to establish reliableassessment and follow-up protocols for chest infections man-aged in the nursing home that approach the quality of theday-to-day management that would occur in the hospital.

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2. Loeb MB, Carusone SBC, Marrie TJ, , et al. Carusone SBC, Marrie TJ,et al. Inter-observer reliability of radiologists’ interpretations of mobilechest radiographs for nursing home-acquired pneumonia. J Am Med DirAssoc 2006;7:416–419.

3. Syrjala H, Broas M, Suramo I, Ojala A, Lahde S. High-resolutioncomputed tomography for the diagnosis of community-acquired pneumo-nia. Clin Infect Dis 1998;27:358–363.

4. Loeb M, Bentley DW, Bradley S, et al. Development of minimum criteriafor the initiation of antibiotics in residents of long-term care facilities:Results of a consensus conference. Infect Control Hosp Epidemiol 2001;22:120–124.

5. Vergauwen C, Drinka PJ, Larson P, Langer E. Lateral chest roentgeno-grams in debilitated nursing home residents. J Am Geriatr Soc 1990;38:1023–1024.

6. Septimus E. Pleural effusion and empyema. In: Mandell GL, Bennett JE,Dolin R, eds. Mandell, Douglas, and Bennett’s Principles and Practice ofInfectious Diseases. 6th ed, vol. 1. Philadelphia, PA: Elsevier ChurchillLivingstone, 2005:845–853.

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8. BNP Consensus Panel 2004. A clinical approach for the diagnostic,prognostic, screening, treatment monitoring, and therapeutic roles ofnatriuretic peptides in cardiovascular diseases. CHF 2004;10(5 Suppl3):1–30.

9. Ray P, Arthaud M, Birolleau S, et al. Comparison of brain natriureticpeptide and probrain natriuretic peptide in the diagnosis of cardiogenicpulmonary edema in patients aged 65 and older. J Am Geriatr Soc2005;53:642–648.

10. Mylotte JM, Goodnough S, Naughton BJ. Pneumonia versus aspirationpneumonitis in nursing home residents: Diagnosis and management.

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11. El-Solh AA, Pietrantoni C, Bhat A, et al. Microbiology of severeaspiration pneumonia in institutionalized elderly. Am J Respir Crit CareMed 2003;167:1650–1654.

12. American Thoracic Society (ATS) and Infectious Disease Society ofAmerica (IDSA). Guidelines for the management of adults with hospi-tal-acquired, ventilator-associated, and healthcare-associated pneumo-nia. Am J Respir Crit Care Med 2005;171:388–416.

13. Kollef MH, Shorr A, Tabak YP, Gupta V, Liu LZ, Johannes RS. Epide-miology and outcomes of health-care-associated pneumonia: Resultsfrom a large US database of culture-positive pneumonia. Chest 2005;

128:3854–3862.

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