Pleural Effusion: Assessment
Pleural effusion is an abnormal collection of fluid in the pleural space. The diagram above, depicts pleural fluid
displacing lung tissue and compressing alveoli. Several mechanisms can result in abnormal fluid build up in the lungs: elevated hydrostatic pressure, increased capillary permeablility and decreased drainage.
- Increased hydrostatic pressure can result from
- Heart failure that increases venous pressure, which in turn elevates hydrostatic pressure in pulmonary capillaries. This can force fluid out of the capillaries into the surrounding lung tissue, eventually collecting in the pleural space (Krishna, 2024).
- Liver failure leading to portal hypertension also increases venous hydrostatic pressure, causing effusion in a similar way.
- Kidney failure and the resulting fluid retention that increases blood volume and hydrostatic pressure (Canadian Cancer Society, 2022).
- Pulmonary embolism and cancer in the lungs can cause localized increased capillary pressure due to vascular shunting (Canadian Cancer Society, 2022).
- Increased capillary permeability
- Inflammation, e.g. pneumonia and any cause of pulmonary vascular endothelial disruption that increases permeability leading to liquid and protein leakage into the lung parenchyma and gravity-dependant collection into the pleural space.
- Decrease albumin and other plasma proteins that occurs in liver failure decreases oncotic pressure of the blood allowing fluid to escape from the capillaries into cavities like the abdominal ascites, pleural effusion and peripheral edema.
- Decreased lymphatic drainage that can occur when cancer obstructs flow can lead to fluid accumulation (Canadian Cancer Society, 2022).
Assessment findings can include: |
Inspection |
- increased respiratory rate
- dyspnea
|
Palpation |
- tactile fremitus decreased or absent.
- chest expansion decreased on the affected side.
- tracheal shift away from affected side
|
Percussion |
|
Auscultation |
- breath sounds and voice sounds decreased or absent.
- bronchial breath sounds and bronchophony, egophony, and whispered pectoriloquy may be heard over the area of the lung that is compressed near the effusion.
|
References
Canadian Cancer Society / Société canadienne du cancer. (reviewed 2022). Fluid buildup on the lungs (pleural effusion). Canadian Cancer Society. https://cancer.ca/en/treatments/side-effects/fluid-buildup-on-the-lung-pleural-effusion
Krishna R, Antoine MH, Rudrappa M. Pleural Effusion. [Updated 2024 Mar 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448189/