Understanding Pleural Diseases: Pleuritis, Pneumothorax, and Effusions

1. Pleural Disease pleuritis, pneumothorax & effusions

2. Pleuritis • Parietal pleura contains many pain fibers • Any inflammatory process can cause pain – “pleuritic pain” worse with deep breathing • Significance many times depends on clinical setting

3. 19 y o college student Develops cough & congestion Similar to “ what’s going around “ Now has pain with deep inspiration 25 y o in third trimester of pregnancy Slipped on ice a few weeks ago & broke leg Has been on bedrest Now with SOB & pain with breathing Pleuritis cases

4. Pneumothorax • Entry of air into the pleural space – • can be a rent in the lungs from a biopsy or due to areas of gas trapping • compromise of the chest wall – air sucked in by negative pleural pressure • Symptoms depend on extent of pneumothorax & patient’s clinical status- air leaks usually last 72 hours

5. Tension Pneumothorax • A true medical emergency ! • Air escapes in to the pleura causing buildup of positive pressure in the thoracic cavity • May occur when patient on mechanical ventilation with air buildup causing compromise of venous return & shock • Patients need immediate decompression

6. Pneumothorax Causes • Iatrogenic – central lines, mechanical ventilation, lung biopsy • Abnormal lungs with areas of blebs, bullae - COPD • Abnormal airways with air-trapping due to ball-valve effect as with asthma • ARDS

9. 21 y o center for BB team Has sudden onset of R sided chest pain & mild dyspnea Patient is uncomfortable but vital signs are WNL 20 y o severe asthmatic Intubated & on mechanical ventilation Suddenly becomes hypotensive & cyanotic Pneumothorax cases

17. Pleural Effusions Diagnostic workup

18. Radiographic signs of Pleural Effusion • Blunting of costophrenic angle on upright film • Elevation or flattening of hemi diaphragm on upright film • Diffuse haziness of hemi thorax on supine film • If large, will cause shift of mediastinum to contra-lateral side

19. Thoracentesis • Helpful diagnostically about 75% of the time • Can be therapeutic if the effusion is large & the patient is SOB at rest • Can safely remove up to 1500 cc of fluid • Especially if contralateral shift of mediastinum • Beware vague chest pain

20. Safe Tapping • Establish fluid is present & free flowing – Obtain lateral decubitus film – fluid level should be uniformly > 1 cm. or ID with U/S • Use ultrasound or CT to identify & locate loculated effusions • Experience decreases complications • Post-tap X-ray may not be necessary unless patient develops coughing, chest pain or dyspnea – PTX present < 1% with no symptoms

21. Relative Contraindications • Uncooperative patient • Bleeding diathesis, anticoagulation • Mechanical Ventilation esp. with high levels of PEEP • Too little fluid – beware of estimations based on CT appearance only

30. Diagnostic Thoracentesis - Tests • Studies to differentiate transudate from exudate : pleural fluid LDH, total protein & possibly albumin • Studies to help sort out an exudate: cell count & differential, glucose, cytology • Studies if warranted: Gram stain, AFB stain & culture, amylase, cholesterol, triglyceride level, pH, adenosine deaminase

31. Re-expansion Pulmonary Edema • Occurs when effusion present > 1 week • With drainage of > 1.5 L or no contralateral shift • Happens 1% thoracentesis with 20% mortality • Treatment is supportive – improves over 48-72 hours • Stop draining fluid if patient c/o SOB or vague chest pain

32. Therapeutic Thoracentesis • Can relieve sense of dyspnea: • Allows expansion of lung • Improves length – tension relationship of chest wall muscles & diaphragm • Creates more normal chest wall – lung working relationship • Degree of relief dependent on rapidity of accumulation & underlying condition of patient

33. What to do with the fluid ……. • Transudates: limited diagnostic possibilities & treatment options • Exudates: huge differential diagnosis & therapeutic options

34. Defining an Exudative Effusion • Ratio of pleural-fluid protein to serum protein > 0.5, pf cholesterol <45 • Ratio of pleural-fluid LDH > 0.6 • Pleural fluid LDH level > 60% upper limits of normal for serum or >200 • Any one of these characteristics means the fluid is an exudate • If exudate only by LDH likely parapneumonic or malignant

35. Transudates = ultra filtrate of serum • CHF – due to increased pulmonary venous pressures, usually bilateral, usually resolves in 48 hours after diuresis • Nephrosis – low oncotic pressures • Atelectasis – increased negative pleural pressure • Ascites – can preferentially form in pleural space, hepatic-hydrothorax

36. Pleural Effusion case #1 • 55 yo S/P large MI a few weeks ago • Presents now with DOE & orthopnea Chest X-ray shows enlarged heart with bilateral effusions R > than L. • Pleural fluid protein is 1.6, Serum protein is 5.8. Fluid LDH is 160, serum LDH is 420. • Echo shows LV ejection fraction of 20%

37. Albumin Gradient • Light’s criteria tend to overcall exudates • Especially in transudaive effusions after diuresis • If difference between albumin in serum minus pleural fluid is > 1.2 than more likely a true transudate • May misidentify 13%

38. Exudates: Diagnostic Dilemma • Mechanisms: • Increase permeability of pleural microcirculation due to inflammation • Impaired lymphatic drainage • Try to narrow down possibilities by using fluid characteristics

39. Large Exudative Effusions • Malignancy • Trauma - hemothorax • Empyema – bacterial infections • Chylothorax – disruption of thoracic duct • Rarely, TB

41. Exudative Effusions by Appearance • Bloody – cancer, pulmonary infarction, penetrating & nonpenetrating trauma, central line malplacement, chondrosarcoma, S/P CABG • Turbid – milky suggest chylothorax or gross pus equals empyema

42. Hemothorax • Defined as pleural fluid hematocrit of 50% of blood hematocrit • Will coagulate & may lead to loculation with complications of fibrothorax & possible empyema • If small, may defibrinate & remain free flowing

43. Exudative Effusions & Cell Count • > 50% lymphocytes – cancer, TB • > 10% eosinophils – blood or air in pleural space, drug reactions, asbestos exposure, paragonimiasis, early CABG, -does not rule out cancer • > 10% basophils – leukemic infiltration • > 50% neutrophils – acute process • > 5% mesothelial cells – TB less likely

44. Para pneumonic Effusion case • 46 y o with long Hx of ETOH abuse • Presents with low grade fever, weight loss & malaise • Physical exam is remarkable for poor dentition & decreased breath sounds on the right • Chest X-ray confirms moderately large pleural effusion

45. Case 2 cont. • Tap reveals a turbid odorous fluid with neutrophilic predominance • Just because, most of the specimens are lost • However the pH comes back at 6.9 • What to do next ??

46. Exudates & Bacterial Infections • Simple parapneumonic effusions are reactive to a pneumonia & resolve with antibiotics. Course is usually very benign • Empyemaor complicated parapneumonic effusions imply active bacterial infection in the pleural space. Failure to recognize & drain can lead to unresolved sepsis & fibro thorax

47. When to worry….. • Empyema means gross pus is present • Complicated parapneumonic effusion is defined by pH < 7.1 or glucose < 40 positive Gram stain or cultures • Borderline complicated is fluid with pH > 7.1 & < 7.2 or glucose > 40 or LDH > 1000 & Gram stain & cultures negative – needs RETAP

49. What to do ….. • Tube thoracostomy & antibiotics • Thrombolytics if loculated or stops draining despite fluid present on X-ray • Decortication if unable to achieve drainage & lung is trapped in fibrinous peel • Untreated may evolve to empyema necessitans or bronchopleural fistula causing overwhelming sepsis

50. Thrombolytics for drainage ? • May be helpful if coupled with DNAse • TPA alone – variable rate of success • Worth a shot if someone poor surgical risk • Instill and clamp tube for 2-4 hours • Dosing usually around 10 -20 mg x 3 days