Management of Bronchopleural Fistula 氣管肋膜廔管

1. Management of Bronchopleural Fistula氣管肋膜廔管 Dr Grace SM Lam ICU Friday Lecture 16th January, 2009

2. Bronchopleural Fistula • Communication between the bronchial tree & pleural space • Mortality varies between 18-67% • Aetiology • Postoperative 2/3 • Non-postoperative 1/3

3. Post-operative BPF • Most commonly follows pneumonectomy (0-9% v 0.5% in lobectomy) • Predisposing factors: • Rt pneumonectomy (shorter Rt main bronchus & single Rt bronchial artery) • Uncontrolled preoperative pleural /pulmonary infection • Preoperative irradiation • Trauma • Postoperative positive pressure ventilation • Faulty closure of bronchial stump

4. Post-pneumonectomy CXRs Day 2 Day 14 Day 1 Day 30 Radiographics 2006;26:1449-1468

5. Acute Post-pneumonectomy BPF Day 22 Tension pneumothorax & Pulmonary flooding Reappearance of air OR a drop in air-fluid level >1.5cm Mediastinal shift Subcutaneous or mediastinal emphysema Contralateral lung consolidation from transbronchial spill Radiographics 2006;26:1449-1468

6. Non-postoperative BPF • Causes: • Necrotizing pneumonia, TB, lung abscess & empyema • ARDS • Persistent spontaneous pneumothorax • Thoracic trauma • Iatrogenic (line placement, pleural biopsy, FOB) • Irradiation & chemotherapy

7. Clinical Presentation • Persistent air leak >24 hours after the development of pneumothorax • Exclude other causes of persistent air leak • An external air leak • Extra-thoracic location of side holes • Disconnections

8. Clinical Presentation • Acute • Sudden SOB, hypotension, coughing up of fluid & blood • Subacute • Insidious onset with fever, wasting, minimally productive cough • Chronic • Fibrosis of pleural space prevents mediastinal shift

9. Diagnosis • Clinical • Instillation of methylene blue through stump followed by its detection in chest tube • Inhalation of different concentrations of oxygen and N2O followed by changes in gas concentration in post-pneumonectomy space • CT scan to delineate the aetiology • Bronchoscopy is both diagnostic & therapeutic

10. General Management • Drainage of pneumothorax & infected pleural space with appropriate size chest tube(s) • Pulmonary flooding: Airway control & position affected lung down • Treat underlying cause, especially infection • Maintain nutritional status Flow through a tube varies exponentially with the radius of the tube

11. Mechanical Ventilation • BPF offers a pathway of least resistance (or high compliance) • Potential problems • Significant loss of tidal volume (VT) • ↓ CO2 excretion • ↓Utilization of inspired O2 • Failure to maintain PEEP • Air flow through fistula delays healing • Inappropriate cycling of ventilator

12. Conventional Ventilation • Goal is to maintain adequate ventilation & oxygenation while↓fistula flow • Minimize the pressure gradient between airway & pleural space • Minimize mean airway pressure • Lowest effective tidal volume • Shorten inspiratory time • Least number of mechanical breaths • Limit PEEP • Discontinue /minimize suction on chest tubes

13. Chest 1986; 90: 321-323 Persistent Bronchopleural Air Leak During Mechanical Ventilation. A Review of 39 Cases. • A retrospective review • Jan 1977 – Dec 1980 • County hospital and regional trauma & burn center in Seattle • Consecutive patients who received mechanical ventilation & developed persistent air leak >24hrs • Patients after cardiac surgery or pulmonary resection were excluded

14. Chest 1986; 90: 321-323

15. Chest 1986; 90: 321-323 • Overall mortality 67% • Increased mortality in: • Late air leak (94% v 45%; P=0.002) • Diagnoses other than chest trauma (P<0.005) • Maximum air leak >500ml/breath (100% v 57%; P<0.05) • Pleural space infection (87% v 54%; P<0.05)

16. Chest 1986; 90: 321-323 • Mode of MV • Assist-control ventilation 33 • Intermittent mandatory ventilation 6 • Only 2 patients had persistent acidemia PH<7.30 despite adjustment of ventilatory settings BPF can usually be managed by conventional ventilation. The need for special ventilation techniques is uncommon.

17. Failure of Conventional Ventilation… • Options: • Chest tube manipulation • Intermittent inspiratory chest tube occlusion • Application of intrapleural pressure at expiration • Independent lung ventilation • High frequency ventilation • Extracorporeal oxygenation

18. Intermittent Inspiratory Chest Tube Occlusion • Synchronizing chest tube occlusion at inspiration • Limit loss of tidal volume on inspiration • Restores pulmonary gas exchange & promotes healing of BPF During Inhalation During Exhalation Chest 1990; 97: 1426-1430

19. Independent Lung Ventilation Crit Care. 2005; 9(6): 594–600

20. Methods of Lung Separation Endobronchial Blockers Double Lumen ETT

21. Methods of Lung Separation Endobronchial Blockers • Can be passed • Along the side, or • Into the lumen Of the single lumen ETT • Final placement requires bronchoscopic guidance • Does not allow ventilation of the obstructed lung (for anatomical lung separation)

22. Methods of Lung Separation Double Lumen ETT • For independent lung ventilation

23. Size of double lumen ETT • Appropriately sized to allow: • Adequate functional separation of the lungs • Access for suctioning and bronchoscopy • Prevent migration of the tube

24. Double Lumen ETT Placement • Confirming position by ascultation following sequential clamping is inaccurate in 38% • Bronchoscopic confirmation is recommended • For a left-sided double lumen ETT, bronchoscopy via: • Tracheal port ~ Carina visualized, without herniation of bronchial cuff • Bronchial port ~ LUL orifice visualized

25. Independent Lung Ventilation • For unilateral BPF • Unaffected lung: • Conventional ventilation • Affected lung: • Conventional ventilation with lower mean airway pressure • CPAP at pressure just below the critical opening pressure of BPF • High frequency ventilation

26. High Frequency Ventilation

27. High Frequency Ventilation Conventional Ventilation High Frequency Ventilation Delivery of small tidal volumes (VT≦VDS) at supra-physiologic frequencies • Gas transport occurs by bulk flow /convection & molecular diffusion • VA = f (VT – VDS) Governs lung volume & oxygenation Frequency Tidal volume & CO2 elimination

28. Gas Transport in HFV • Longitudinal gas transport : • Coaxial flow • Molecular diffusion • Mixing of fresh & exhaled gas : • Lateral diffusion • Turbulent flow at airway bends & bifurcations • Intra-alveolar pendelluft • Most proximal alveoli by bulk flow

29. HFV in BPF • Flow through an air leak is proportional to: • Cross-sectional area of the leak • Time held at high airway pressure ∴High frequency ventilation may reduce fistula leak

30. HFV in BPF • Superior to conventional ventilation in controlling PCO2 & PO2 in proximal BPF & normal lung parenchyma • Controversial in peripheral BPF with parenchymal disease (e.g. ARDS) • Initial settings: • Begin with MAP similar to or slightly lower than that of conventional ventilation • Use higher frequency (13-15Hz) • Amplitude to achieve minimal chest movement

31. Potential Complications of HFV • Suboptimal humidification • Inspissation of airway secretions • Necrotizing tracheobronchitis • Gas trapping

32. Treatment of BPF Operative Non-operative Conservative Chemical pleurodesis via chest drain Bronchoscopic methods • Drainage of infected pleural space, closure of BPF, and obliteration of dead space: • Omental flap • Transsternal transpericardial bronchial closure • Eloesser muscle flap • Thoracoplasty 60cm Patient Underwater seal ANZ J Surg. 2006 Aug;76(8):754-6

33. Bronchoscopy in BPF • Diagnostic: • Direct visualization of proximal fistula • Distal fistula localized by systematically occluding bronchial segments by balloons • Therapeutic: • Distal small fistulas (~1mm) can be sealed by various agents: Glue, blood patch, coils, gel foams, lead shots • No evidence to support the use of one over another

34. Bronchoscopy in BPF Amplatzer device Endobronchial valve (Emphasys) Designed primarily for endoscopic lung volume reduction in emphysema. One-way valve that prevents entry of air but allows drainage of secretions. Thorax 2007; 62: 830-3 Commonly used for closure of atrial septal defects. For closure of larger BPF. Large range of device sizes & can be matched to size of fistula. Chest 2008; 133(6): 1481-4

35. Bronchoscopy in BPF • Endobronchial Watanabe Spigot (EWS) (Novatech, Grasse, France) • A silicone-made bronchial filler for bronchial occlusion • Flexible bronchoscope under LA J Bronchol 2003; 10: 264-7

36. Bronchial Occlusion With Endobronchial Watanabe Spigot J Bronchol 2003; 10: 264-7 • 63 cases in Japan between April 2000 and March 2002 • 40 intractable pneumothorax • 12 pyothorax with bronchial fistula • 7 pulmonary fistula, 1 bronchial fistula • 1 bronchobiliary, 1 bronchoesophageal fistula, and 1 bronchogastric fistula

37. Bronchial Occlusion With Endobronchial Watanabe Spigot • Technically successful bronchial occlusion • In 58/60 (96.7%) • Average 4 EWS/case used J Bronchol 2003; 10: 264-7

38. Take Home Messages • BPF is an abnormal communication between bronchial tree & pleural space associated with significant mortality • No established guidelines in the management of BPF • Early recognition, drainage, & management of infection are critical • Recognizes the potential problems with positive pressure ventilation, although conventional ventilation usually suffices • List of available options represent personal experience not subjected to vigorous testing

39. References • Radiographics 2006;26:1449-1468 • Crit Care 2005; 9(6): 594–600 • Chest 1986; 90: 321-323 • Chest 1990; 97: 1426-1430 • Crit Care 2005; 9(6): 594–600 • Chest 2005; 128(6): 3955-65 • Chest 2008; 133(6): 1481-4 • Thorax 2007; 62: 830-3 • J Bronchol 2003; 10: 264-7

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