FFS: Pleural Effusion • LITFL • FFS

Pleural effusion is the accumulation of fluid in the pleural space. Diagnosis is usually clinical and confirmed on CXR, though ultrasound or CT may be required. Pleural aspiration may be needed for diagnosis or to relieve dyspnoea.

Pathology

Pleural effusions are classified as transudates or exudates, though the distinction is not always clear-cut.

Transudates

CCF
Hypoalbuminaemia
Hypothyroidism
Meigs syndrome

Exudates

Infection (including TB)
Malignancy
Connective tissue disease
Subdiaphragmatic (e.g. subphrenic abscess, pancreatitis)
Irradiation
Trauma

Clinical Assessment

History

Degree of dyspnoea
Cough, haemoptysis
Orthopnoea, exertional dyspnoea (CCF)
Risk factors: malignancy, asbestos, TB
History of trauma
Medications, especially anticoagulants

Examination

Vital signs and pulse oximetry
On affected side:
- ↓ Breath sounds
- ↓ Vocal resonance
- Dull percussion note

Investigations

Bloods

FBC
CRP
U&Es, glucose
Coagulation profile
ABGs

Imaging

CXR: primary investigation for effusion
Ultrasound: confirms effusion, guides aspiration
CT chest: useful if malignancy, consolidation, or loculation suspected

Pleural Aspiration

Send fluid for:

M&C (incl. AFB stain)
Cell counts (RBCs, neutrophils, lymphocytes)
Cytology
Biochemistry:
- Protein & LDH to classify transudate vs exudate
- pH: <7.2 suggests infection
- Glucose: ↓ in infection, RA
- Rheumatoid factor
- Triglycerides (chylothorax)

Transudate vs Exudate

Test	Exudate	Transudate
Protein	>30 g/L	<30 g/L
LDH	>200 IU/L	<200 IU/L
Pleural:serum protein ratio	>0.5	<0.5
Pleural:serum LDH ratio	>0.6	<0.6

Management

Pleural tap
- Indicated for dyspnoea or diagnosis
- Large effusions may require drainage
- Refer to radiology for ultrasound-guided tap if small or loculated
Treat underlying cause
Pleurodesis
- For recurrent symptomatic effusions
- Particularly useful in malignancy

Appendix 1

pleural effusion right side CXR — Typical appearance of a moderate right sided pleural effusion. This effusion was in a 37 year old man. There is an upper meniscus level, confirming that fluid is present in the pleural space. A perfectly horizontal level suggests the co-existence of the pneumothorax. The opacity is dense and homogenous suggesting a pleural effusion. The presence of air bronchograms is more suggestive of consolidation.

References

FOAMed

Nickson C. Pleural Effusion. CCC
Rippey J. Lung ultrasound: Pleural effusion. LITFL
Rippey J. Pleural Effusion Case 001. LITFL
Rippey J. Pleural Effusion Case 002. LITFL
Rippey J. Ultrasound Case 025. LITFL
Brims F. CXR Case 096. LITFL

Resources

Rea H, McAuley S, Jayaram L, Garrett J, Hockey H, Storey L, O’Donnell G, Haru L, Payton M, O’Donnell K. The clinical utility of long-term humidification therapy in chronic airway disease. Respir Med. 2010 Apr;104(4):525-33.
Helviz Y, Einav S. A Systematic Review of the High-flow Nasal Cannula for Adult Patients. Crit Care 2018; 22: 71
Parke RL, Bloch A, McGuinness SP. Effect of Very-High-Flow Nasal Therapy on Airway Pressure and End-Expiratory Lung Impedance in Healthy Volunteers. Respir Care. 2015 Oct;60(10):1397-403
Li J, Albuainain FA, Tan W, Scott JB, Roca O, Mauri T. The effects of flow settings during high-flow nasal cannula support for adult subjects: a systematic review. Crit Care. 2023 Feb 28;27(1):78.

Fellowship Notes

…more FFS

Caitlin Rigler

BA, BM BCh University of Oxford, PgCert (Medical Education)University of Dundee. Aspiring medical physician with a particular interest in respiratory medicine, public health and medical education

James Hayes

Educator, magister, munus exemplar, dicata in agro subitis medicina et discrimine cura | FFS |