Empyema differential diagnosis
Empyema Microchapters |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Differential diagnosis
Empyema must be diffrentiated from pneumonia, lung abscess, lung cancer and parapneumonic effusions as shown below:
Variable | Empyema Thoracis | Lung abscess | Pleural effusion | Pneumonia | Lung cancer |
---|---|---|---|---|---|
Presentation | Variable presentation but may follow long standing pneumonia | Usually has history of aspiration pneumonia, alcoholics, drug abusers, seizure disorder, have undergone recent general anesthesia, or have a nasogastric or endotracheal tube. | Usually follows pneumonia as a complication | presents with fever, pleuritc chest pain, cough | mostly asymptomatic but may have cough productive with hemoptysis and chronic history of smoking |
Causes | In general any bacteria can cause an empyema, however different bacteria are associated with different rates of empyema formation.[1] Common causes include bacteroides, fusobacterium, haemophilus influenzae, pneumococcal infections, staphylococcus aureus, streptococcus, TB | Lung abscess is commonly caused by bacterial infections and these include bacteroides, peptostreptococcus and prevotella mostly after aspiration | Common causes of transudative pleural effusion include;[1][2][3][4][5] left ventricular failure, Nephrotic syndrome, and cirrhosis, while common causes of exudative pleural effusions[6] are bacterial pneumonia and malignancy | Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, parasites, and chemical injury to the lungs | Direct cause of lung cancers is DNA mutations that often result in either activation of proto-oncogenes (e.g. K-RAS) or the inactivation of tumors suppressor genes (e.g. TP53) or both. The risk of these genetic mutations may be increased following exposure to environmental components example smoking |
Laboratory findings | Laboratory findings are non specific example leukocytosis, sputum samples for gram staining and culture. Other tests include urine antigen test, PCR, C-reactive protein and procalcitonin | The laboratory findings are non specific including: neutropenia, hyponatremia, hypokalemia, hypercalcemia, respiratory acidosis, hypercarbia, hypoxia, and tumor cells in sputum and pleural effusion cytology. | |||
Physical examination | Physical examination increased respiratory rate, low oxygen saturation, difficulty breathing, bronchial breathe sounds, crackling sounds, or increased whispered pectoriloquy. | ||||
CXR | A homogenous opacification is noted at the affected side. The costophrenic angle is obliterated with a meniscus. | CXR shows areas of diffused opacities. | |||
Chest ultrasound | Ultrasound in empyema is positive for suspended microbubble sign, air fluid level, curtains sign and loss of gliding sign.[1] | Ultrasound in lung abscess is negative for suspended microbubble sign, curtains sign and loss of gliding sign but air fluid level may be seen,.[2] | Ultrasonography is not needed in making diagnosis of pleural effusion however, chest or upper abdominal ultrasound may show subpulmonic effusion.[3][4][5] | Not reqiured unless complicated with empyema | |
CT scan | Seen as a lung mass whose cavity is regular with smooth and regular lumen, well-defined defined boundary and shape changes with change in patient's position.[6] Mass may resolve on antibiotics
The split pleura sign is present (most reliable sign to differentiate empyema from lung abscess) |
Lung mass whose cavity is rregular with undulated lumen, irregular-poorly defined boundary and shape does not change with change in patient's position.[7] Mass may resolve on antibiotics |
|
Seen as a lung spiculated irregular solid mass that does not resolve on antibiotics |
References
- ↑ Lin FC, Chou CW, Chang SC (2004). "Differentiating pyopneumothorax and peripheral lung abscess: chest ultrasonography". Am J Med Sci. 327 (6): 330–5. PMID 15201646.
- ↑ Lin FC, Chou CW, Chang SC (2004). "Differentiating pyopneumothorax and peripheral lung abscess: chest ultrasonography". Am J Med Sci. 327 (6): 330–5. PMID 15201646.
- ↑ Almeida FA, Eiger G (2008). "Subpulmonic effusion". Intern Med J. 38 (3): 216–7. doi:10.1111/j.1445-5994.2007.01619.x. PMID 18290818.
- ↑ Connell DG, Crothers G, Cooperberg PL (1982). "The subpulmonic pleural effusion: sonographic aspects". J Can Assoc Radiol. 33 (2): 101–3. PMID 7107669.
- ↑ Halvorsen RA, Thompson WM (1986). "Ascites or pleural effusion? CT and ultrasound differentiation". Crit Rev Diagn Imaging. 26 (3): 201–40. PMID 3536306.
- ↑ Baber CE, Hedlund LW, Oddson TA, Putman CE (1980). "Differentiating empyemas and peripheral pulmonary abscesses: the value of computed tomography". Radiology. 135 (3): 755–8. doi:10.1148/radiology.135.3.7384467. PMID 7384467.
- ↑ Baber CE, Hedlund LW, Oddson TA, Putman CE (1980). "Differentiating empyemas and peripheral pulmonary abscesses: the value of computed tomography". Radiology. 135 (3): 755–8. doi:10.1148/radiology.135.3.7384467. PMID 7384467.