Background: Conventional medical wisdom long held that patients with pneumothorax (PTX) who require positive pressure ventilation (PPV) should undergo tube thoracostomy to prevent enlarging or tension pneumothorax, even if otherwise they would be managed expectantly.¹

• Small retrospective and observational studies have demonstrated safety to an observational approach for both occult (only detectable on CT) and larger PTXs even in patients requiring noninvasive or invasive mechanical ventilation, whether traumatic/iatrogenic or spontaneous.^2-6
• The Western Trauma Association recently released a guideline for the management of traumatic PTX, which includes observation with 6-hour follow up CXR for patients with small (<20% aka <2cm from chest wall on CXR or <35 mm on CT scan) hemodynamically stable pneumothoraces, even if mechanical ventilation is required.⁷
  • They note a 10% subsequent failure rate (i.e. chest tube requirement) with no difference between patients who do or do not undergo PPV. 
• The OPTICC trial, found however, that while the rate of respiratory distress development was not different between those randomized to observation vs initial chest tube management, there was an increase from a 25% chest tube requirement in the obs group to a 40% failure rate in patients requiring >4 days of mechanical ventilation.⁸ 

Bottom Line: The cardiopulmonar-ily stable patient with small PTX doesn’t need empiric tube thoracostomy simply because they’re receiving positive pressure ventilation. If you are unlucky enough to still have them in your ED at day 5 in these COVID times, provide closer monitoring as the observation failure rate may increase dramatically around this time.

References

1. Enderson BL, Abdalla R, Frame SB et al. Tube thoracostomy for occult pneumothorax: a prospective randomized study of its use. J Trauma. 1993;35(5):726-730.
2. Brasel KJ, Stafford RE, Weigelt JA, Tenquist JE, Borgstrom DC. Treatment of occult pneumothoraces from blunt trauma. J Trauma. 1999;46(6):987-991. doi:10.1097/00005373-199906000-00001
3. Wu SH, Horng MH, Lin KH, Hsu WH. Spontaneous Recovery of Ventilator-Associated Pneumothorax. Respiration. 2013;85:367-374. doi: 10.1159/000342890
4. Smith JA, Secombe P, Aromataris E. Conservative management of occult pneumothorax in mechanically ventilated patients: A systematic review and meta-analysis. J Trauma Acute Care Surg. 2021 Dec 1;91(6):1025-1040. doi: 10.1097/TA.0000000000003322. 
5. Walker SP, Barratt SL, Thompson J, Maskell NA. Conservative Management in Traumatic Pneumothoraces: An Observational Study. Chest. 2018 Apr;153(4):946-953. doi: 10.1016/j.chest.2017.10.015.
6. Llaquet Bayo H, Montmany Vioque S, Rebasa P, Navarro Soto S. Resultados del tratamiento conservador en pacientes con neumotórax oculto [Results of conservative treatment in patients with occult pneumothorax]. Cir Esp. 2016;94(4):232-6. Spanish. doi: 10.1016/j.ciresp.2015.01.010.
7. de Moya M, Brasel KJ, Brown CVR, et al. Evaluation and management of traumatic pneumothorax: A Western Trauma Association critical decisions algorithm. J Trauma Acute Care Surg. 2022;92(1):103-107. doi:10.1097/TA.0000000000003411
8. Clements TW, Sirois M, Parry N, et al. OPTICC: A multicentre trial of Occult Pneumothoraces subjected to mechanical ventilation: The final report. Am J Surg. 2021;221(6):1252-1258. doi: 10.1016/j.amjsurg.2021.02.012. Epub 2021 Feb 20.