Incidence and risk factors of iatrogenic pneumothorax after thoracentesis in emergency department settings

Abstract

Background: There is a lack of data regarding the incidence and associated factors of pneumothorax following thoracentesis conducted in emergency department (ED) settings. The present study aims to determine the incidence of pneumothorax following thoracentesis in ED settings and evaluate the association of specific demographics, clinical, and procedure factors with thoracentesis- related pneumothorax.Methods: We retrospectively reviewed the medical records of 3,067 thoracentesis cases in the ED of a tertiary care, university-affiliated hospital between January 2009 and December 2014. To evaluate the factors associated with the occurrence of pneumothorax following thoracentesis, matched controls were used with a case to control ratio of 1:5.Results: Of the 3,067 cases that received thoracentesis, 19 cases of pneumothorax were observed (0.62%). Patients with pneumothorax had significantly lower weight and body mass index (BMI) than those without pneumothorax (51.0 vs. 61.2 kg, 20.0 vs. 22.6; P<0.001, respectively). In the multivariate logistic regression analysis, being underweight, defined as a BMI of <18.5 [OR, 5.2 (95% CI, 1.3-21.2); P=0.021] was significantly associated with the occurrence of pneumothorax.Conclusions: The incidence of pneumothorax following thoracentesis was very low in the present study. However, clinicians should be aware of the risk of pneumothorax in underweight patients during thoracentesis. Further prospective studies are required to clarify the results of the present study.