S44 Risk factors for recurrence of primary spontaneous pneumothorax: analysis from the RAMPP trial

Abstract

<h3>Introduction and Objectives</h3> Primary Spontaneous Pneumothorax (PSP) is a common condition with a high recurrence rate (28–33%).^{1, 2, 3} Current guidelines suggest referral for recurrence prevention surgery after the second episode. Identifying patients at greater risk of recurrence would allow a more stratified approach. A number of factors have been proposed previously, but none have been robustly proven. This study used a large prospectively collected dataset from the RAMPP (Randomised Ambulatory Management of Primary Pneumothorax) Trial¹ in the UK to assess risk factors for pneumothorax recurrence up to 12 months. <h3>Methods</h3> The RAMPP dataset included 423 patients: 236 were managed actively (either ambulatory or standard care arms) and an observational cohort of 187 patients with small, minimally symptomatic pneumothoraces managed conservatively. A Cox proportional hazards model was used to assess risk of recurrence by the following variables: patient age, sex, size of initial pneumothorax, smoking history (tobacco and marijuana), personal history of prior pneumothorax history, family history and treatments given. <h3>Results</h3> The overall recurrence rate at 12 months was 20.6% (87/423) with a significantly lower rate in the conservatively-managed observational cohort (22/187, 11.8%), than the ambulatory and standard care arms (28/117, 23.9%, and 37/119, 31.1%, respectively) (p &lt; 0.001). Personal history of previous episode of pneumothorax significantly increased the risk of pneumothorax (See figure 1) (p = 0.014). No other risk factors were significant in predicting recurrence. <h3>Conclusion</h3> Patients with small, minimally symptomatic pneumothorax have a low recurrence rate (11.8%). Previous history of pneumothorax is associated with increased risk of recurrence. Further work is required to identify other risk factors to determine who may benefit from early recurrence prevention procedures. <h3>References</h3> Hallifax RJ. <i>Lancet</i> 2020;<b>396</b>:39–49. Hallifax RJ. <i>JAMA</i> 2018;<b>320</b>(14):1471–1480. Bobbio A. <i>Thorax</i> 2015;<b>70</b>:653–58.