Bhatnagar, R. & Maskel, N. The modern diagnosis and management of pleural effusions (2015) BMJ 351
Question 1
A 34 year old male as admitted to the respiratory inpatient unit with progressive shortness of breath. A chest X-ray reveals a large right sided unilateral pleural effusion. An ultrasound guided pleural aspirate is undertaken, the results are shown below:
Pleural fluid pH 7.16
Pleural protein 45 g/dl
Serum protein 50 g/dL
Pleural LDH 342 IU/L
Serum LDH ULN 280 IU/L
Gram stain/ microscopy – no organisms or polymorphs seen
Cytology – atypical cells
What is the most correct response with regards to the pleural fluid analysis
(A) Transudate as the pleural protein is less than the serum protein
(B) Transudate as the serum LDH is less than the pleural LDH
(C) Exudate as the pleural pH < 7.2
(D) Exudate as the pleural protein is > two-thirds the serum protein
(E) Exudate as the pleural LDH : serum LDH is >0.6
E: This is clearly an exudate as it fulfils lights criterion (1: pleural protein: serum protein >0.5, 2: pleural LDH: serum LDH >0.6 or 3: pleural fluid LDH >2/3 ULN of serum LDH). Pleural pH is not a part of lights criterion. A pH <7.2 is strongly indicative of an effusion. Rheumatoid arthritis can also cause this pattern.
Question 2:
A 78 year old patient with metastatic gastric adenocarcinoma is admitted with progressive dyspnoea with super-imposed type 2 respiratory failure. On examination he has stony dullness to both bases, greatest on the right side with bronchial breathing above this area. CT of his chest confirms a large pleural effusion bilaterally. He has both sides drained. The initial analysis shows an exudative effusion and cytology shows atypical cells without any malignant cells seen.
What is the most CORRECT answer
(A) Malignancy is the most common cause of an exudative pleural effusion
(B) Transudative causes are more common than exudative causes of pleural effusion
(C) Talc pleurodesis would be preferred over insertion of an indwelling catheter for the management of his effusion
(D) Pleural fluid cytology has at best a sensitivity of 60%, therefore one cannot rule out malignancy as a cause
(E) Type 2 respiratory failure is not associated with large pleural effusions
D: The sensitivity of cytology is at best 60%. However it is highly specific. Talc pleurodesis obliterates the pleural space in 80% of cases. In the TIME-2 trial, patients with malignant pleural effusions were randomised to receive either standard talc pleurodesis or an indwelling pleural catheter, and the study found no difference between the two arms in the primary end point of patient reported dyspnoea at six weeks. Indwelling catheters can be left in for many months and even years without change, and there is a low risk of infection. Furthermore, if they do get infected then they do not necessarily need to be removed. Talc has been shown to be the best at producing a chemical pleurodesis. Exudates account for 57% of all pleural effusions according to the BMJ review, and ofthese infections are more common than malignancy. Type 2 respiratory failure may occur due to a failure of ventilation, given decreased tdal volume not overcome by increased respiratory rate.
Question 3
A 52 year old female who suffers from chronic alcoholism is seen in emergency after failure to cope. She is hypotensive and tachycardic. Her chest X-ray shows a large left sided pleural effusion that causes midline shift. Initial diagnostic thoracocentecis shows an exudative effusion with gram stain showing gram positive rods. Her pleural pH is 7.16. She is taken to theartre and underwent a thoracotomy and drainage. Unfortunately her inflammatory markers continued to rise and she had persistent low grade temperatures. A repeat Chest X-ray showed re-accumulation of the fluid. A chest drain is re-inserted. In addition to the chest drain, what additional step would you take?
(A) TpA (alteplase) + DNAse alpha into drain
(B) TpA alone
(C) DNAse alpha alone
(D) Urokinase alone
(E) Streptokinase and Urokinase
A: Combination of TpA and DNAse alpha is better than either alone according to the MIST-2 trial published in the new england journal of medicine. It improved fluid drainage in patients with pleural infection and reduced the frequency of surgical referral and the duration of the hospital stay compared to single agent therapy N Engl J Med 2011; 365:518-526
Question 1
A 34 year old male as admitted to the respiratory inpatient unit with progressive shortness of breath. A chest X-ray reveals a large right sided unilateral pleural effusion. An ultrasound guided pleural aspirate is undertaken, the results are shown below:
Pleural fluid pH 7.16
Pleural protein 45 g/dl
Serum protein 50 g/dL
Pleural LDH 342 IU/L
Serum LDH ULN 280 IU/L
Gram stain/ microscopy – no organisms or polymorphs seen
Cytology – atypical cells
What is the most correct response with regards to the pleural fluid analysis
(A) Transudate as the pleural protein is less than the serum protein
(B) Transudate as the serum LDH is less than the pleural LDH
(C) Exudate as the pleural pH < 7.2
(D) Exudate as the pleural protein is > two-thirds the serum protein
(E) Exudate as the pleural LDH : serum LDH is >0.6
E: This is clearly an exudate as it fulfils lights criterion (1: pleural protein: serum protein >0.5, 2: pleural LDH: serum LDH >0.6 or 3: pleural fluid LDH >2/3 ULN of serum LDH). Pleural pH is not a part of lights criterion. A pH <7.2 is strongly indicative of an effusion. Rheumatoid arthritis can also cause this pattern.
Question 2:
A 78 year old patient with metastatic gastric adenocarcinoma is admitted with progressive dyspnoea with super-imposed type 2 respiratory failure. On examination he has stony dullness to both bases, greatest on the right side with bronchial breathing above this area. CT of his chest confirms a large pleural effusion bilaterally. He has both sides drained. The initial analysis shows an exudative effusion and cytology shows atypical cells without any malignant cells seen.
What is the most CORRECT answer
(A) Malignancy is the most common cause of an exudative pleural effusion
(B) Transudative causes are more common than exudative causes of pleural effusion
(C) Talc pleurodesis would be preferred over insertion of an indwelling catheter for the management of his effusion
(D) Pleural fluid cytology has at best a sensitivity of 60%, therefore one cannot rule out malignancy as a cause
(E) Type 2 respiratory failure is not associated with large pleural effusions
D: The sensitivity of cytology is at best 60%. However it is highly specific. Talc pleurodesis obliterates the pleural space in 80% of cases. In the TIME-2 trial, patients with malignant pleural effusions were randomised to receive either standard talc pleurodesis or an indwelling pleural catheter, and the study found no difference between the two arms in the primary end point of patient reported dyspnoea at six weeks. Indwelling catheters can be left in for many months and even years without change, and there is a low risk of infection. Furthermore, if they do get infected then they do not necessarily need to be removed. Talc has been shown to be the best at producing a chemical pleurodesis. Exudates account for 57% of all pleural effusions according to the BMJ review, and ofthese infections are more common than malignancy. Type 2 respiratory failure may occur due to a failure of ventilation, given decreased tdal volume not overcome by increased respiratory rate.
Question 3
A 52 year old female who suffers from chronic alcoholism is seen in emergency after failure to cope. She is hypotensive and tachycardic. Her chest X-ray shows a large left sided pleural effusion that causes midline shift. Initial diagnostic thoracocentecis shows an exudative effusion with gram stain showing gram positive rods. Her pleural pH is 7.16. She is taken to theartre and underwent a thoracotomy and drainage. Unfortunately her inflammatory markers continued to rise and she had persistent low grade temperatures. A repeat Chest X-ray showed re-accumulation of the fluid. A chest drain is re-inserted. In addition to the chest drain, what additional step would you take?
(A) TpA (alteplase) + DNAse alpha into drain
(B) TpA alone
(C) DNAse alpha alone
(D) Urokinase alone
(E) Streptokinase and Urokinase
A: Combination of TpA and DNAse alpha is better than either alone according to the MIST-2 trial published in the new england journal of medicine. It improved fluid drainage in patients with pleural infection and reduced the frequency of surgical referral and the duration of the hospital stay compared to single agent therapy N Engl J Med 2011; 365:518-526