Respiratory for PLAB 1

A 68 year old man with known heart failure has increasing breathlessness. He has bilateral pitting oedema, a raised jugular venous pressure and stony dullness at both lung bases with reduced breath sounds. A chest radiograph confirms bilateral effusions. An aspirate shows a pleural fluid protein to serum protein ratio of 0.3 and a pleural LDH well below the exudate threshold. What is the SINGLE most likely diagnosis?

1. Exudative effusion A thicker, protein-rich fluid from infection, cancer, a blood clot in the lung, or inflammation. Here, bilateral protein-poor effusions with signs of heart failure points elsewhere.
2. Haemothorax Blood in the space around the lung after an injury. That does not match bilateral protein-poor effusions with signs of heart failure.
3. Pneumonia with parapneumonic effusion An effusion that comes along with pneumonia, which can turn into a more serious, complicated one. It does not fit bilateral protein-poor effusions with signs of heart failure.
4. Pulmonary embolism A small, protein-rich effusion with sharp chest pain on breathing and low oxygen. But bilateral protein-poor effusions with signs of heart failure does not point to it.
5. Transudative effusion correct Correct. Fluid on both sides with a low protein and a low LDH, in a patient with heart failure. Light's criteria class this as a thin, low-protein fluid.

The point: A pleural effusion is fluid building up around the lung. It causes breathlessness, a dull, solid-sounding note when the chest is tapped, quieter breath sounds, and a quieter voice sound heard through the stethoscope over the fluid. A sample is taken (aspirated) and checked against Light's criteria to tell a thin, watery fluid (transudate) from a thicker, protein-rich fluid (exudate). It counts as an exudate if the fluid's protein is more than half of the blood's protein level, if the fluid's LDH (an enzyme) is more than 0.6 times the blood's LDH level, or if the fluid's LDH is more than two-thirds of the normal upper blood LDH level. Transudates come from heart failure, liver scarring (cirrhosis), or a kidney condition called nephrotic syndrome, and they are treated by treating the cause. Exudates come from infection, cancer, a blood clot in the lung (pulmonary embolism), or inflammation, and they need further tests. The fluid is sent to check protein, LDH, acidity (pH), sugar (glucose), cells under the microscope (cytology), and for germs. A pH below 7.2 in an infected effusion means pus has collected (an empyema) or a complicated infection, and it needs a tube put in to drain it (a chest drain). Blood-stained fluid suggests cancer, and pus means an empyema.

Source: BTS Pleural Disease Guideline British Thoracic Society · tier 2, specialty society or college

A 68 year old man with known heart failure has increasing breathlessness. He has bilateral pitting oedema, a raised jugular venous pressure and stony dullness at both lung bases with reduced breath sounds. A chest radiograph confirms bilateral effusions. An aspirate shows a pleural fluid protein to serum protein ratio of 0.3 and a pleural LDH well below the exudate threshold. What is the SINGLE most appropriate initial investigation?

1. Pleural fluid protein, LDH, pH, glucose, cytology and culture The full set of tests that finds infection, cancer, and pus collections (empyema). Here, bilateral protein-poor effusions with signs of heart failure points elsewhere.
2. Assess for heart failure, liver and renal disease Checking for the causes of a thin, low-protein effusion, done by examining the patient and with a heart scan (echocardiogram) and blood tests. That does not match bilateral protein-poor effusions with signs of heart failure.
3. Pleural aspiration and Light's criteria correct Correct. These tests tell a thin fluid from a thick one, and here they confirm a thin fluid, which means treating the cause rather than the fluid itself.
4. Chest radiograph Shows the effusion as a blunted angle at the bottom corner of the lung and a curved fluid line, and it estimates how much fluid there is. It does not fit bilateral protein-poor effusions with signs of heart failure.
5. Pleural fluid pH A pH below 7.2 in an infected effusion means a chest drain is needed. But bilateral protein-poor effusions with signs of heart failure does not point to it.

The point: A pleural effusion is fluid building up around the lung. It causes breathlessness, a dull, solid-sounding note when the chest is tapped, quieter breath sounds, and a quieter voice sound heard through the stethoscope over the fluid. A sample is taken (aspirated) and checked against Light's criteria to tell a thin, watery fluid (transudate) from a thicker, protein-rich fluid (exudate). It counts as an exudate if the fluid's protein is more than half of the blood's protein level, if the fluid's LDH (an enzyme) is more than 0.6 times the blood's LDH level, or if the fluid's LDH is more than two-thirds of the normal upper blood LDH level. Transudates come from heart failure, liver scarring (cirrhosis), or a kidney condition called nephrotic syndrome, and they are treated by treating the cause. Exudates come from infection, cancer, a blood clot in the lung (pulmonary embolism), or inflammation, and they need further tests. The fluid is sent to check protein, LDH, acidity (pH), sugar (glucose), cells under the microscope (cytology), and for germs. A pH below 7.2 in an infected effusion means pus has collected (an empyema) or a complicated infection, and it needs a tube put in to drain it (a chest drain). Blood-stained fluid suggests cancer, and pus means an empyema.

Source: BTS Pleural Disease Guideline British Thoracic Society · tier 2, specialty society or college

A 68 year old man with known heart failure has increasing breathlessness. He has bilateral pitting oedema, a raised jugular venous pressure and stony dullness at both lung bases with reduced breath sounds. A chest radiograph confirms bilateral effusions. An aspirate shows a pleural fluid protein to serum protein ratio of 0.3 and a pleural LDH well below the exudate threshold. What is the SINGLE most appropriate immediate management?

1. Therapeutic aspiration or drainage for symptom relief Draining a large effusion that is causing symptoms, taking off no more than 1 to 1.5 litres at a time so the lung does not swell back too fast and cause fluid on the lung. But bilateral protein-poor effusions with signs of heart failure does not point to it.
2. Antibiotics for a parapneumonic effusion Given alongside draining the fluid when the effusion has become complicated. That does not match bilateral protein-poor effusions with signs of heart failure.
3. Pleurodesis or an indwelling pleural catheter for a recurrent malignant effusion A treatment that sticks the lung lining together, or a catheter left in place, to stop the fluid coming back and to relieve symptoms. It does not fit bilateral protein-poor effusions with signs of heart failure.
4. Treat the underlying cause of a transudate correct Correct. Water tablets and getting the heart failure under control will clear the fluid, because it built up from raised pressure in the veins.
5. Intrapleural fibrinolytics for a loculated empyema Clot-dissolving drugs put into the chest, used when a drain alone cannot clear a pocketed collection of pus. Here, bilateral protein-poor effusions with signs of heart failure points elsewhere.

The point: A pleural effusion is fluid building up around the lung. It causes breathlessness, a dull, solid-sounding note when the chest is tapped, quieter breath sounds, and a quieter voice sound heard through the stethoscope over the fluid. A sample is taken (aspirated) and checked against Light's criteria to tell a thin, watery fluid (transudate) from a thicker, protein-rich fluid (exudate). It counts as an exudate if the fluid's protein is more than half of the blood's protein level, if the fluid's LDH (an enzyme) is more than 0.6 times the blood's LDH level, or if the fluid's LDH is more than two-thirds of the normal upper blood LDH level. Transudates come from heart failure, liver scarring (cirrhosis), or a kidney condition called nephrotic syndrome, and they are treated by treating the cause. Exudates come from infection, cancer, a blood clot in the lung (pulmonary embolism), or inflammation, and they need further tests. The fluid is sent to check protein, LDH, acidity (pH), sugar (glucose), cells under the microscope (cytology), and for germs. A pH below 7.2 in an infected effusion means pus has collected (an empyema) or a complicated infection, and it needs a tube put in to drain it (a chest drain). Blood-stained fluid suggests cancer, and pus means an empyema.

Source: BTS Pleural Disease Guideline British Thoracic Society · tier 2, specialty society or college