Hong Kong Respiratory Medicine

Drs Samuel Lee and Johnny WM Chan, Department of Medicine, Queen Elizabeth Hospital

The management of pneumothorax can broadly include the removal of air from the pleural cavity and the prevention of recurrence in indicated patients.

Factors to consider on the management options to relieve a pneumothorax
These include the type and size of pneumothorax as well as the clinical condition and symptoms of the patient.

1. Type of pneumothorax
Primary spontaneous pneumothorax (PSP), in the absence of underlying lung diseases, can be managed by more conservative measures such as observation or simple aspiration. For secondary spontaneous pneumothorax (SSP), hospital admission with close observation and oxygen supplement should usually be required, with a view to immediate drainage relief if necessary. A more conservative approach is usually adopted for asymptomatic iatrogenic pneumothorax.

2. Size of pneumothorax
Larger pneumothoraces would normally be an indication for intercostal tube drainage. In BTS guidelines, a rim between the lung margin and chest wall of 2cm was used as a cut-off point1 while in the ACCP guidelines, the apex-to-cupola distance of 3cm was employed instead.2

3. Clinical conditions and symptoms
Intercostal tube drainage should in general be considered for symptomatic or clinically unstable patients. In ACCP guideline,2 the presence of the following signs signifies clinical instability: respiratory rate >24 per minute, heart rate <60 or >120 per minute, abnormal blood pressure, SaO2 at room air <90% and the inability to complete a full sentence. Moreover, signs of tension pneumothorax have to be looked out, namely the deviation of trachea and mediastinum to the contralateral side and rapid development of respiratory failure.


Management Options to relieve pneumothorax

1. Simple observation
Simple observation can be considered in patients with small primary pneumothoraces with minimal symptoms. It has been estimated that 1.25% of the volume of the hemithorax could be absorbed each 24 hours.3 In contrast to stable asymptomatic patients with PSP, observation must be adopted with caution in SSP patients, and hospital admission should be advised. High flow oxygen should be given, though with caution in patients with COPD, to hasten the re-expansion process.

2. Simple aspiration
Simple aspiration was proposed as the first-line intervention of all symptomatic (and/or > 2cm size) PSP and even for selected cases of SSP in the BTS guidelines, though it is not recommended in the ACCP guidelines. Owing to the relatively high failure rates, only asymptomatic SSP patients with age under 50 and a rim small than 2 cm would be considered for aspiration in BTS guidelines. Randomized controlled studies revealed similar efficacies, less pain and shorter hospital stays when compared to intercostal tube drainage.4-8 In Hong Kong, local unpublished preliminary data revealed that, except in Emergency Departments,9-10 simple aspiration has not been commonly performed. Nevertheless, it can be considered in iatrogenic pneumothoraces. The use of new pneumothorax kits like CASP catheter system using Seldinger technique, with or without the use of 1-way valve like Helmlich valve, might improve the popularity of the technique in the future.

3. Chest tubes
Chest tubes still appear to be the commonest method to treat the symptomatic pneumothoraces. In both BTS and ACCP guidelines, the use of small bore catheters (<20F) is advocated in most stable cases, which is easier to insert and cause less pain and complications, especially in patients of smaller build. However, in patients on mechanical ventilation or those with suspected big broncho-pleural fistulas such as post-operative stump dehiscence, bigger drains should be considered to cater for the larger leaks.14 The following Drainage systems are usually being used:

a. One- bottle system
Drainage depends on gravity, with the drain connected to a tube submerged in around 2 cm of water that provides under-water seal. This is good enough in simple cases where suction is not required.

b. Two-bottle system
When there is concomitant drainage of fluid, the water-seal level will be elevated, creating greater resistance. Adding a container bottle before the water-seal bottle might solve the problem. Another form of 2-bottle system involves a water-seal bottle connected to a second suction-regulating bottle to gauge the pressure created via external (e.g. wall) suction.

c. Three-bottle water seal system
A suction regulating bottle is added to the two-bottle system to accommodate the simultaneous drainage of air and fluid. The water column in the bottle will reflect the suction generated via an external source. Handy units serving the same function and design are commercially available.

d. One-way valve systems
This is a relatively costly option in facilitating transfer or discharge for stable cases, preferably for use in those without significant leakages of the pneumothorax as the presence of leakage can not be monitored easily.



Application of Suction

1. Indications
- persistent lung collapse and/or persistent air leakage
- removal of co-existing fluid, like blood or pus

2. Timing and amount of suction to be applied
- immediate suction after drainage is usually not necessary and might produce complications like reperfusion pulmonary oedema
- can be applied after 48 hours if re-expansion is suboptimal. Drainage with 10-20 cmH2O is recommended in ordinary situations.1



3. Common methods in applying and monitoring of suction

(a) Via a suction monitoring bottle in a 2- or 3-bottle system
The suction force is measured by the height of water column in the bottle. Though technically simple and economical, this is bulky and much vigilance is necessary for monitoring. Moreover, the amount of suction measured and hence applied is limited by the size of the bottles, with an upper limit of about 10cmH2O only for the relatively small bottles in our institution. Commercially available integrated units operating on the same concept can provide equivalent but more expensive alternatives.

(b) Via continuous vacuum regulators
Negative pressure being directly applied from the wall suction and only the underwater seal bottle is necessary. These can provide a more precise control even at the “low suction” range (0-5kPa), which otherwise would be only a rough estimate from the usual adjustment available in the wards. Its small size and wide range of suction that can be applied are the major advantages. However, it is more expensive.

(c) Via Gomco system
Combining the pump and the water bottles into a single system. It is convenient and does not need additional source of wall suction. The maximum suction provided is up to 25 cm H2O. However, it is bulky and the suction provided is only intermittent, which might occasionally not be desirable in management of pneumothroax. Moreover, the price per unit is even higher than the vacuum regulator at the time of writing.

Clamping of the chest drain

Although being a controversial issue with no evidence to demonstrate its usefulness,11 clamping of chest drains is not absolutely contraindicated in both BTS and ACCP guidelines. However, chest drains should only be clamped with much caution and is contraindicated with persistent air leakage. Presence of experienced nursing staff, together with close monitoring of oxygen saturation and clinical condition would be necessary.1 With clinical deterioration such as increasing dyspnoea or oxygen desaturation, the clamp should be opened immediately.



Prevention of Recurrence: medical pleurodesis

According to international guidelines1, medical pleurodesis is reserved for those who are too frail or unwilling to undergo surgical pleurodesis, which provides a more definitive prevention of recurrence. Tetracycline group such as doxycline and minocycline is the commonest agents employed with an overall efficacy about 70% and is recommended by BTS guidelines as the first-line agents of choice1. Talc is also widely used with its higher reported efficacy (about 90%) and lower cost. Both agents are associated with pain and fever, but more severe complications such as respiratory failure and ARDS had been associated with the use of talc.12-13 The use of mixed talc with smaller particles had been suggested to the cause of these severe systemic reactions.12

Referral to surgeons

Apart from presence of persistent air-leak or failure of re-expansion of more than 5-7 days, when there is the occurrence of a second ipsilateral or a first contralateral pneumothorax, surgical evaluation might be necessary.1 A first occurrence of SSP has also been indicated for pleurodesis, in contrast to PSP.2 The profession (such as divers or pilots) and choice of patients should also be taken into consideration.1-2

References:
1. British Thoracic Society Standards of Care Committee. BTS guidelines for the management of spontaneous pneumothorax. Thorax 2003;58(Suppl II):ii39-ii52
2. ACCP Pneumothorax Consensus Group. Management of Spontaneous Pneumothorax. ACCP Delphi Consensus Statement. Chest 2001;119:590-602
3. Kirchen LT Jr, Swartzel RL. Spontaneous pneumothorax and its treatment. JAMA 1954;155:24-29
3. Archer GJ, Hamilton AAD, Upadhyag R, et al. Results of simple aspiration of pneumothoraces. Br J Dis Chest 1985;79:177-182
4. Noppen M, Alexander P, Driesen P, et al. Manual aspiration versus chest tube drainage in first episodes of primary spontaneous pneumothorax. A multicenter, prospective, randomized pilot study. Am J Respir Crit Care Med 2002; 165: 1240-1244.
5. Spencer-Jones J. A place for aspiration in the treatment of spontaneous pneumothorax. Thorax1985;40:66-67
6. Andrivert P, Djedaim K, Teboul J-L et al. Spontaneous pneumothorax: comparison of thoracic drainage vs immediate or delayed needle aspiration. Chest 1995; 108:335-340
7. Harvey J, Prescott RJ. Simple aspiration versus intercostals tube drainage for spontaneous pneumothorax in patients with normal lungs. BMJ 1994;309:1338-1339
8. Chan SS, Lam PK. Simple aspiration as initial treatment for primary spontaneous pneumothorax; results of 91 consecutive cases. Journal of Emergency Med.2004;28:133-138
9. Siu AY, Chung CH. A case series of using aspiration catheter for the management of spontaneous pneumothorax. Hong Kong J Emerg Med 2003;10:233-237
10. So SY, Yu DY. Catheter drainage of spontaneous pneumothorax suction or no suction, early or late removal? Thorax 1982;37:46-48
11. Rinadlo JE, Owens GR, Roger RM. Adult Respiratory Distress syndrome following instillation of talc. J Thorac Cardiovasc Surg 1983:;85:523-526
12. Kenndy L, Rush VW, Strange C et al. Pleurodesis using talc slurry. Chest1994;106:342-346
13. Baumann MH. What size chest tube? What drainage system is ideal? And other chest tube management questions. Curr Opin Pulm Med 2003; 9: 276-281