Shorter symptoms onset to emergency department presentation time predicts failure of needle aspiration in primary spontaneous pneumothorax

Abstract

Objective: To evaluate factors in predicting the failure of needle aspiration in primary spontaneous pneumothorax, in particular the interval between symptom onset and emergency department presentation. Methods: This is a retrospective cohort study carried out from January 2010 to October 2012 in two public hospitals in Hong Kong. All consecutive adult patients aged 18 or more who attended the emergency departments in the study period with the diagnosis of primary spontaneous pneumothorax, where needle aspiration was performed as the primary treatment were recruited. Age, smoking status, previous pneumothorax, symptom interval, size of pneumothorax and aspirated gas volume were included in the analysis. The outcome was successful or failed needle aspiration. Logistic regression was used to identify independent predictors of failed needle aspiration. Results: A total of 196 patients were included. Overall, 105 patients (53.6%) were treated successfully with no recurrence upon discharge. Among those failure patient, 30 patients (15.3%) failed as evidence by the chest X-ray taken immediately after the procedure while 61 patients (31.1%) failed upon subsequent chest X-ray. Multivariate logistic regression showed factors independently associated with failure of needle aspiration included size of pneumothorax (apex to cupola distance) (odds ratio [OR]=1.022, 95% confidence interval [CI]=1.009-1.039, p=0.001) and symptoms onset to emergency department presentation time (OR=0.987, 95% CI=0.976-0.999, p=0.028). Conclusions: Large pneumothorax and shorter symptoms onset to emergency department presentation time were associated with higher failure rate of needle aspiration for primary spontaneous pneumothorax.