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Three Part Question

In [patients with traumatic pneumothorax] does [insertion of an intercostal drain] reduce [morbidity, mortality or complications]?

Clinical Scenario

A 23 year old woman attends your department having been kicked in the chest by her horse. On arrival, she is complaining of right sided chest pain. Her vital signs are normal and she has no respiratory distress. Your examination reveals an isolated chest injury. You arrange a portable chest x-ray which shows a small, right sided, apical pneumothorax. You wonder whether you can avoid inserting a chest drain, and manage this patient conservatively.

Search Strategy

The Pubmed and EMBASE databases were searched via the Healthcare Databases Advanced Search interface. Search terms were as follows:

(("pneumothorax").ti,ab AND ("trauma").ti,ab) AND (("tube thoracostomy").ti,ab OR ("thoracostomy").ti,ab OR ("chest tube*").ti,ab OR ("chest drain").ti,ab)

A search of the BestBET database was also conducted.

Search Outcome

A total of 1148 papers were found. After review of the abstracts and full texts, including cross-referencing the bibliographies of potentially relevant papers, 17 were deemed relevant and of suitable quality for inclusion. Of these, there were 11 retrospective observational studies, 5 prospective observational studies and 1 randomised trial. 2 previous BestBETs from 2006 and 2008 were found.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hegarty, M. 1976 South Africa	131 patients with traumatic chest injury. 58 patients with pneumothorax <1.5cm.	Prospective, observational study.	Requirement for delayed chest tube thoracostomy.	8/58 required tube thoracostomy after initial conservative management. No in-hospital deaths.	Pneumothoraces and haemothoraces not separated.
Knottenbelt & van der Spuy 1990 South Africa	803 patients with traumatic pneumothorax. 333 patients managed with observation (pneumothorax size less than 1.5cm).	Prospective, observational study.	Requirement for delayed chest tube thoracostomy.	33/333 required tube drainage.	No definition of failure of conservative management. Long-term outcomes not evaluated.
Garramone, R. et al. 1991 USA	26 patients with 31 occult pneumothoraces. 14/31 pneumothoraces treated with tube thoracostomy.	Retrospective chart review.	Requirement for delayed chest tube thoracostomy.	No patients required tube thoracostomy after initial conservative management.	Single centre study. Small study numbers. Individual clinician discretion for treatment received. No clear reasoning behind the cut off size of pneumothorax to be treated conservatively.
Bridges, K. et al. 1993 USA	35 patients with occult pneumothorax.	Retrospective chart review.	Requirement for delayed chest tube thoracostomy.	10/35 patients received immediate tube thoracostomy. 5/25 remaining patients required delayed chest drain for clinical deterioration.	Retrospective. No definition of clinical deterioration. No follow up or complications described.
Enderson, B. et al. 1993 USA	40 patients with occult pneumothorax on abdominal CT. 21 managed with observation.	Prospective, observational study.	ICU length of stay.	3.2 days (observation) v 2.8 days (tube thoracostomy)	Single centre study so results not generalisable.
			Hospital length of stay.	17.6 days (observation) v 12.9 days (tube thoracostomy)
			Complications.	Observation: tension pneumothorax n=3, progression of pneumothorax n=5, pneumonia n=1, empyema n=1 atelectasis n=3 Tube thoracostomy: pneumonia n=1, atelectasis n=8.
Johnson, G. 1996 UK	53 patients with 54 pneumothoraces, 29/54 managed with observation.	Retrospective chart review.	Requirement for delayed chest tube thoracostomy.	2/29 underwent tube thoracostomy drainage for increasing pneumothorax size.	Small study numbers, no specification of pneumothorax classification.
Wolfman, N. et al. 1998 USA	44 occult pneumothoraces. 27 managed with observation.	Prospective non-randomised study.	Requirement for delayed chest tube thoracostomy.	3/27 pneumothoraces required tube thoracostomy	Single centre, non-randomised
Brasel, K. et al. 1999 USA	39 patients with occult pneumothoraces. 21/40 randomised to observation.	Prospective, randomised control trial.	Hospital length of stay (median).	5 days (observation) v 8 days (chest tube)	Single centre study, small numbers, poor recruitment.
			ICU length of stay (median).	1 day in both groups
			Complications.	Observation: retained haemothorax n=1, respiratory distress n=3, pneumothorax progression n=3 (2 ventilated patients underwent tube thoracostomy) Tube thoracostomy: pneumonia n=2, respiratory distress n=1 pneumothorax progression n=4
Barrios, C. et al. 2008 USA	59 occult pneumothoraces managed conservatively.	Retrospective trauma registry review.	Requirement for delayed chest tube thoracostomy.	51/59 did not require tube thoracostomy. 16/20 receiving positive pressure ventilation required no chest drain.	No defined protocol for conservative management.
Wilson, H. et al. 2009 Canada	68 occult pneumothoraces as a result of blunt trauma. 35/68 treated with tube thoracostomy.	Retrospective trauma registry review.	Hospital length of stay.	10 days (tube thoracostomy) v 7 days (conservative), p=0.01	Little use on CT in the early years of the study may under-represent the number of cases. Retrospective review.
			Mortality.	11.4% (tube thoracostomy) v 9.1% (conservative), p=0.75
			Pneumothorax progression/tension pneumothorax in conservative group.	0/33 patients.
Moore, F. et al. 2011 USA	569 blunt trauma patients with 588 occult pneumothoraces. 448/569 were initially observed.	Prospective, observational, multicentre study.	Requirement for delayed chest tube thoracostomy.	27/448 patients failed observation	The paper focusses on reasons for failing observation, with no comparison between the treatment group and observation group.
Kong V. et al. 2015 South Africa	125 patients sustaining stab wounds to the chest, with a CXR confirmed small traumatic pneumothorax (<2cm at apex). All patients were managed with close observation. Those with worsening pneumothorax on 12 hour x-ray, or clinical deterioration, had chest drain insertion.	Retrospective, chart review.	To determine whether small traumatic pneumothoraces <2cm be managed conservatively.	Of 125 patients, 4 (3%) required chest drain insertion: 1 – 1.5cm PTX = 1 1.5 – 2cm PTX = 3. No subsequent readmissions, morbidity or mortality. Mean length of hospital stay 1.2 days.	Retrospective case note review so not all required data may be available. Single centre study so results may not be generalisable. Small number of patients analysed with no statistical analysis.
Zhang, M. et al. 2016 Singapore	83 patients with occult pneumothorax. 48/83 were initially observed.	Retrospective trauma registry review.	Hospital length of stay.	5.5 days (observation) v 13 days (tube thoracostomy), p=0.008	Retrospective. Single centre study.
			Mortality.	2.1% (observation) v 5.7% (tube thoracostomy) p=0.57
			Complications.	8.3% (observation) v 20% (tube thoracostomy)
Eddine, S. et al. 2018 USA	336 adult patients presenting to a Level 1 Trauma Centre with chest wall injury, undergoing CT chest at time of admission.	Retrospective chart review.	Patients were categorised as largest air pocket of pneumothorax measuring more than 35mm or 35mm or less from the pleura to the mediastinum. Management was either immediate tube thoracostomy or observation Failure of observation defined as a need for delayed tube thoracostomy or secondary intervention.	47 patients underwent immediate tube thoracostomy. 272 patients had PTX 35mm or less: 91% successfully observed with 9% requiring a chest drain. 17 patients had PTX more than 35mm: 41% failed observation and required chest drain insertion secondary to radiological progression (37.5%), physiological deterioration or development of pleural effusion/haemothorax/ tension pneumothorax. PPV of predicting successful observation 35mm or less = 90.8%; OR for predicting successful observation 0.142 (95%CI 0.047 – 0.428, p<0.001).	Patients requiring mechanical ventilation excluded- these may represent a high-risk group more likely to fail observation. 94.3% of injuries caused by blunt trauma. The clinical course of penetrating chest injury may vary. The decision to place an intercostal drain was left to individual clinician discretion. Retrospective, single centre study.
Walker, S. et al. 2018 UK	602 patients with traumatic pneumothoraces at one UK Major Trauma Centre. 277/602 were treated conservatively.	Retrospective, observational study.	% of patients initially managed conservatively requiring subsequent thoracic intervention.	10% (n=25). 23 patients had chest drain insertion, 2 underwent surgery. Mean duration to intervention was 2.96 days.	Low rate of penetrating chest wall injury. Variation in initial imaging modality. High risk, unwell patients were likely under-represented in the conservative treatment arm. Inclusion criteria required a 3 day hospital stay or admittance to the high dependency unit; this likely provides bias against conservatively managed patients who are more likely to be discharged early. Hence the overall rate of effective conservative treatment is likely greater than observed. Patients receiving immediate intervention likely to have different baseline characteristics to the conservative arm.
			Median hospital length of stay.	10 days for both groups p=0.35
			Median ICU length of stay.	2 days (non-conservative management) v 0 days (observation) p= <0.001.
			Mortality.	11.1% (non-conservative management) v 7.2% (observation) p=0.1.
			Complications of chest tube insertion	10%. (Drain re-sited 4.4%; subsequent drain after removal of first 2.4%; drain dislodged 1.2%; intraparenchymal drains 1.5%; empyema 0.6%; guidewire in pleural cavity 0.3%).
Saricam, M. et al. 2010 Turkey	78 patients with CT confirmed traumatic pneumothorax secondary to isolated blunt thoracic trauma.	Single centre, retrospective, observational study.	To compare treatment approaches (conservative v chest tube) in patients of varying traumatic pneumothorax size. Patients were split into 4 groups based on the size of pneumothorax on CT as a percentage of the pleural cavity: Group A 0-10% Group B 10-20% Group C 20-50% Group D more than 50%.	Group A (n =12) – 17% required chest drain due to increasing size of pneumothorax. One patient developed recurrent pneumothorax at 10 days. Group B (n =18) – 44% required chest drain Group C (n= 22) – 55% required chest drain. Two patients developed recurrent pneumothorax at 10 days. Group D (n= 26) – 100% required chest drain. 12% of all patients with chest drains required a second tube thoracostomy for surgical emphysema, malposition of the initial tube, failure of lung re-expansion.	Single centre study so results may not be generalisable. Retrospective observational study so some data may be missing. Small patient numbers. No statistical analysis. No formal comparison – chest drains in each group were inserted based on clinician discretion.
Mahmood, I. et al. 2020 Qatar	150 blunt trauma patients with occult pneumothorax. 133/150 initially managed conservatively.	Retrospective trauma database review.	Requirement for delayed tube thoracostomy.	5/133 patient failed conservative management.	Retrospective study. Statistical analysis is not on an intention to treat basis- patients who failed initial observation were included in the tube thoracostomy group.
			Mortality.	4% (observation) v 0% (tube thoracostomy) p=0.65
			Hospital length of stay.	7 days (observation) v 8.5 days (tube thoracostomy) p=0.05

Comment(s)

Current Advanced Trauma Life Support (ATLS) guidance for the management of traumatic pneumothorax recommends treatment with chest drain insertion. Small, asymptomatic pneumothoraces may be managed with observation and aspiration at the clinician’s discretion, but no further guidance is given in this regard. Two BestBETs in 2006 and 2008 concluded that simple, small and/or occult traumatic pneumothoraces can be safely managed with careful observation. Since these reviews, further evidence has been published, as presented in this BET. Despite the heterogeneity of study design, in general conservatively managed patients were observed for signs of clinical or radiological deterioration during admission to hospital for at least 24 hours. Clinical parameters of deterioration include: respiratory distress, haemodynamic instability and reduced level of consciousness. Radiological deterioration includes: increasing size of pneumothorax, tension pneumothorax, haemothorax and pleural effusion. Rates of failed observation, leading to subsequent chest drain insertion, range from 0%-20%. Several patients underwent repeat chest x-ray during admission. If there were no signs of clinical or radiological deterioration patients were discharged with follow up. Saricam et al. report 3/78 patients who had recurrent pneumothorax on repeat CXR at 10 days, with no clinical signs of pneumothorax. No other studies reported further morbidity, mortality or complications in conservatively managed patients. Length of hospital stay was at worst no longer in the conservatively managed patients than those undergoing tube thoracostomy, with multiple studies demonstrating a reduced length of stay. Patients with a large pneumothorax were consistently at an increased risk of failing conservative treatment. Four papers provided data whereby a specific size of pneumothorax could be deemed safe to observe. Kong et al. demonstrated that only 1/105 patients with traumatic pneumothorax less than 1.5cm on chest x-ray (CXR) required tube thoracostomy. Saricam et al. found 17% of patients with pneumothorax <10% of the thoracic volume required a chest drain following initial conservative management. In Eddine et al.’s study, only 9% of patients with pneumothorax greater than or equal to 35mm, as measured on thoracic CT, failed conservative treatment, compared to 41% in the greater than 35mm group. Garramone et al. recommended conservative treatment should the pneumothorax measure less than 5mm x 80mm on CT. The reported rate for complications related to tube thoracostomy (classified as insertional, positional, removal, post-removal and equipment-related) ranged from 20-40%, therefore safe conservative treatment is an attractive option. Patients with large pneumothoraces or those with clinical signs of respiratory or haemodynamic compromise require immediate tube thoracostomy. This review demonstrates that patients with small traumatic pneumothoraces and no respiratory distress can be safely managed with observation alone, with failure of conservative management occurring in up to 20% of patients.

Editor Comment

J of Trauma

Clinical Bottom Line

Patients attending with normal vital signs and a traumatic pneumothorax less than 1.5cm on CXR or less than 10% thoracic volume on CT can be managed with conservative treatment without affecting morbidity, mortality or complications. All patients should be observed for at least 24 hours post-injury for signs of clinical or radiological deterioration. Should these occur, chest drain insertion should be considered. Patients discharged without intervention should undergo outpatient follow up.

References

1. Hegarty, M. A conservative approach to penetrating injuries of the chest. Experience with 131 successive cases. Injury 1976; pp. 53-59.
2. Knottenbelt, J. & van der Spuy, J. Traumatic pneumothorax: a scheme for rapid patient turnover. Injury 1990; pp.77-80.
3. Garramone, R., Jacobs, L. & Sadhev,P. An objective method to measure and manage occult pneumothorax. Surgery, Gynecology & Obstetrics 1991; pp. 257-261.
4. Bridges, K. et al. CT detection of occult pneumothorax in multiple trauma patients. Journal of Emergency Medicine 1993; pp. 179-186.
5. Enderson, B. et al. Tube Thoracostomy for Occult Pneumothorax: A Prospective Randomized Study of its use. The Journal of Trauma, Injury, Infection and Critical Care 1993; pp. 726-730
6. Johnson, G. Traumatic pneumothorax: is a chest drain always necessary? Emergency Medicine Journal. 1996; pp. 173-174.
7. Wolfman, N. et al. Validity of CT classification on management of occult pneumothorax. American Journal of Roentgenology 1998; pp.1317-1320.
8. Brasel, K. et al. Treatment of Occult Pneumothoraces from Blunt Trauma. The Journal of Trauma, Injury, Infection and Critical Care 1999; pp. 987-990.
9. . Barrios, C. et al. Successful management of occult pneumothorax without tube thoracostomy despite positive pressure ventilation. American Journal of Surgery 2008; pp. 958-961.
10. Wilson, H. et al. Occult pneumothorax in the blunt trauma patient: tube thoracostomy or observation? Injury 2009; pp. 928-931.
11. Moore, F. et al. Blunt traumatic occult pneumothorax: is observation safe? The Journal of Trauma. 2011; p. 1019-1025.
12. Kong, V. et al. The selective conservative management of small traumatic pneumothoraces following stab injuries is safe: experience from a high-volume trauma in South Africa. European Journal of Emergency Surgery 2015; pp. 75-79.
13. Zhang, M. et al. Occult pneumothorax in blunt trauma: is there a need for tube thoracostomy? European Journal of Trauma and Emergency Surgery 2016; pp. 785-790.
14. Eddine, S. et al. Observing pneumothoraces: The 35-millimeter rule is safe for both blunt and penetrating chest trauma. Journal of Trauma and Acute Care Surgery 2019; pp. 557-564.
15. Walker, S. et al. Conservative Management in Traumatic Pneumothoraces: An Observational Study. Chest 2018; pp. 946-953.
16. Saricam, M. et al. Management of traumatic pneumothorax in isolated blunt chest trauma. The European Research Journal 2019; pp. 306-310.
17. Mahmood, I. et al. Occult Pneumothorax in Patients Presenting with Blunt Chest Trauma: An Observational Analysis. Qatar Medical Journal 2020; pp. 1-10