From the Guidelines
Left-sided pleural effusion after Coronary Artery Bypass Grafting (CABG) is most commonly caused by inflammation and irritation of the pleura due to the surgical procedure, and it typically persists for a variable duration, with some studies suggesting that large or symptomatic effusions may require intervention, as reported by 1. The main causes of left-sided pleural effusion after CABG include:
- Surgical trauma to the chest wall and pleura
- Atelectasis (lung collapse)
- Lymphatic disruption
- Pericardial inflammation Management of left-sided pleural effusion after CABG typically involves:
- Monitoring: Regular chest X-rays to track effusion size, with decisions to intervene based on a combination of clinical and radiological features, as suggested by 1
- Conservative treatment: Most cases resolve spontaneously, but some may require intervention, such as thoracocentesis, if the effusion is large or symptomatic, with an estimated volume >480 mL, as reported by 1
- Thoracentesis: Ultrasound-guided thoracocentesis has replaced surgical tube thoracostomy as the initial intervention of choice, and is well tolerated by patients, as noted by 1
- Pain management: NSAIDs or acetaminophen to reduce inflammation and discomfort Patients should be advised to:
- Perform deep breathing exercises
- Maintain good posture
- Stay hydrated
- Report any worsening shortness of breath or chest pain The effusion occurs due to increased capillary permeability and lymphatic disruption from surgical manipulation, and as healing progresses, the body reabsorbs the fluid, leading to gradual resolution of the effusion, with some studies suggesting that dedicated follow-up and intervention on pleural effusions can enhance recovery rates by up to 15%, as reported by 1.
From the Research
Cause of Left-Sided Pleural Effusion after CABG
- The exact cause of left-sided pleural effusion after Coronary Artery Bypass Grafting (CABG) is unclear 2, 3, 4.
- Possible factors contributing to the development of pleural effusions include diaphragm dysfunction, internal mammary artery harvesting, postcardiac injury syndrome, and trapped lung 5, 6.
- The majority of pleural effusions are left-sided, suggesting that the surgical procedure itself may play a role in their development 2, 4.
Persistence of Left-Sided Pleural Effusion after CABG
- Most pleural effusions resolve spontaneously within a few weeks to months after CABG 2, 5.
- However, some pleural effusions can persist for several months, requiring specific therapeutic interventions such as video-assisted thoracic surgery (VATS) or intrapleural injection of sclerosing agents 2, 3.
- The duration of pleural effusion can vary, with some studies reporting a median time to resolution of 80 days 2 and others reporting persistence for up to 2 years or more 3.
Characteristics of Left-Sided Pleural Effusion after CABG
- Pleural effusions after CABG can be characterized as exudative or transudative, with lymphocytosis being a common feature 2, 3.
- The pleural fluid can be bloody or non-bloody, with bloody effusions tend to occur earlier and be more easily managed with therapeutic thoracenteses 4.
- Histologic examination of pleural biopsies can show follicular lymphoid hyperplasia, non-necrotizing granulomatous reaction, and mild inflammatory infiltrate 2, as well as pleural thickening and fibrosis 3.