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Auscultating to Diagnose Pneumonia

Three Part Question

In [adult patients presenting to the Emergency Department with suspected community acquired pneumonia] is [auscultation] reliable in [confirming the diagnosis]?

Clinical Scenario

A 50 year-old lady presents with a fever and cough. Physical examination of her chest reveals crackles in the left base. You wonder whether this means that you can be confident of a diagnosis of pneumonia before the results of further investigations are obtained.

Search Strategy

Medline 1966 to 2007 February Week 1 using OVID interface
Embase 1980 - 2007 Week 7 using OVID interface
[exp Pneumonia, Bacterial/ OR exp Pneumonia/ OR] AND [exp Auscultation OR auscultat$.mp.] limit to humans and English language

Search Outcome

110 papers were identified in Medline and 192 in Embase. Five were relevant to the three-part question.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Wipf, J. E. et al
54 patients with respiratory symptoms (cough and change in sputum) who presented to the Emergency Department.Prospective, blinded diagnostic study Chest exam performed by 2 (of 3) physicians (blinded to patient vital signs and history). Chest radiograph read by radiologist used as gold standard.Sensitivity of overall clinical diagnosisRange 47% to 69%1. Small patient group. 2. Group characteristics: Entirely male, all late-middle aged, many with underlying respiratory/cardiac pathology. 3. Long study period affecting standardisation between patients. 4. Chest radiograph used as gold standard which can be insensitive and nonspecific.
Specificity of overall clinical diagnosis58% to 75%
Multivariate analysis of rales (crackles) in presence of pneumoniaOdds Ratio 3.73
Interrobserver reliability for clinical diagnosis of pneumoniaPaired kappa ranged from 0.18 to 0.32, indicating only fair agreement
Leuppi, J.D. et al
243 consecutive patients attending the Emergency Department with chest symptoms.Prospective, double blinded study Diagnosis proposed before and after auscultation by a physician (with initial access to referring letter and patient history) and compared with the (seperate) diagnosis made on discharge letter.Contribution of lung auscultationUnchanged diagnosis after auscultation in 96.4% of cases1.Chest symptoms were not described for initial recruitment. 2.Auscultatory findings were not described. 3.Influence of patient's history to the diagnosis proposed would contribute to findings despite attempts to control this. The study was not specific for pneumonia and so a cardiac history (eg chest pain with orthopnea) with crackles will give a very different impression to sputum with crackles.
Predictive value of normal lung auscultation for absence of lung or heart diseaseOdds Ratio 0.12 (95%CI 0.053-0.29)
Hopstaken et al

246 adult patients presenting to 25 GP's with symptoms and signs consistent with lower respiratory tract infection (LRTI). Signs and symptoms recorded by GP on standard form; PA and lateral chest radiographs blindly interpreted by radiologist on day 3 formed the gold standard.Prospective diagnostic cohort studyAuscultation abnormality for diagnosis of pneumoniaPresent in 84% of patients; Odds ratio 2.0 (95% CI 0.6 - 6.9). PPV 14.2%; NPV 92.3%Interobserver reliability not assessed. No sample size calculation. Wide confidence intervals suggest the study may be underpowered.
Accuracy of crackles for diagnosis of pneumoniaPresent in 20.6% of patients; Odds ratio 1.5 (0.7-3.7); PPV 18.0%; NPV 87.6%
Osmer and Cole
United States
200 'random' cases of young men admitted to hospital with radiographic evidence of acute pneumonia between September 1963 and August 1964. Auscultatory findings recorded by "internists skilled in chest diseases" compared to chest radiograph results, as reported by three radiologists.Retrospective diagnostic cohortAbsence of auscultatory findingsOccurred in 50 (25%) of cases.Retrospective analysis. No sample size calculation. "Random" method for identification of cases not described. No mention of blinding. Only cases of pneumonia included (not an undifferentiated group).
Absence of ralesOccurred in 98 (49%) of cases.
Auscultatory abnormality in same location as chest radiograph abnormalityOccurred in 52 (26%) of cases.
Metlay et al
United States
Published studies of patients suspected of having pneumonia, which evaluated clinical signs for diagnostic accuracy (identified in Medline). Gold standard was chest radiography. All studies were reviewed for quality.Systematic reviewInterobserver reliability of chest signsKappa scores: Crackles 0.41; Wheezes 0.51; Bronchial breath sounds 0.32. (Indicates only fair-moderate agreement for each).Only Medline was searched. No attempts to retrieve unpublished data. No attempt to meta-analyse the data. Confidence intervals not always stated. Exact P values not stated.
Any chest finding for diagnosis of pneumoniaLR+ 1.3, LR- 0.57 (95% CI 0.39-0.83). (P<0.05). This is insufficient to safely confirm or exclude pneumonia in practice.
Crackles for diagnosis of pneumoniaLR+ ranged from 1.6-2.7; LR- 0.78-0.87. (P<0.05)
Bronchial breath sounds for diagnosis of pneumoniaLR+ 3.5; LR- 0.90. (P<0.05)
Rhonchi for diagnosis of pneumoniaLR+ ranged from 'not significant' - 1.5; LR- 'not significant' - 0.76


The stethoscope remains a hallmark of the physician's diagnostic armoury. However, the studies identified report it's limited diagnstic efficacy for acute pneumonia. Further, the studies reported high rates of interobserver variability. Other conditions, including the kind of stethoscope used, the conditions it is used in (noisy resuscitation room vs quiet cubicle) and the experience of the examiner, are likely to influence sensitivity and specificity. The studies identified suggest that auscultation has a limited role in the diagnosis of actue pneumonia in Emergency Department. Of course, this does not mean that the stethoscope should be thrown away. A careful physical examination may guide the Emergency physician in the formulation of differential diagnoses and selection of appropriate investigations.

Editor Comment

Abbreviations: PPV: Positive predictive value; NPV: Negative predictive value; LR+: Positive likelihood ratio; LR-: Negative likelihood ratio; CI: Confidence intervals.

Clinical Bottom Line

In the Emergency Department, pneumonia cannot reliably be confirmed or excluded by auscultation, or indeed physical examination, alone.


  1. Wipf, J.E; Lipsky, B.A; Hirschmann, J.V; Boyko, E.D; Takasugi, J; Peugeot, R.L; Davis, C.L. Diagnosing Pneumonia by Physical Examination. Relevant or Relic? Archives of Internal Medicine 1999;159:1082-1087
  2. Leuppi, J.D; Dieterle, T; Koch, G; Martina, B; Tamm, M; Perruchoud, A.P; Wildeisen, I; Leimenstoll, B.M. Diagnostic value of lung auscultation in the emergency room setting Swiss Medical Weekly 2005;135:520-524
  3. Hopstaken RM; Muris JWM; Knottnerus JA; Kester ADM; Rinkens PELM; Dinant GJ Contributions of symptoms, signs, erythrocyte sedimentation rate, and C-reactive protein to a diagnosis of pneumonia in acute lower respiratory tract infection British Journal of General Practice 2003; 53: 358-364
  4. Osmer JC; Cole BK. The stethoscope and roentgenogram in acute pneumonia Southern Medical Journal 1966; 1: 75-77
  5. Metlay JP; Kapoor WN; Fine MJ. The rational clinical examination: Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination JAMA 1997; 278(17): 1440-1445