Thoracic empyema that develops from thoracic injury, such as traumatic pneumothorax, can lead to life-threatening conditions, posing an important clinical issue [2]. However, published case reports in the PubMed database do not mention traumatic pneumothorax complicated by thoracic empyema. Therefore, this case highlights an important clinical issue. In our case, traumatic pneumothorax with rib fractures was treated with tube thoracostomy without antibiotic prophylaxis, but the case was complicated by thoracic empyema. The empyema was intractable, and the patient underwent radical surgery with decortication of the lung and chest wall repair with rib and clavicle fracture fixation.

In the present case, the possible main causes of the thoracic empyema included ineffective chest tube drainage for persistent pneumothorax. Other possible causes included progressive chest wall instability, and restricted ventilation failure due to obesity [8]. Although there was no instability at the time of presentation, rib and clavicular fractures morphology, and obesity could have caused the delayed chest instability. It was speculated that placement of the chest tube may have exacerbated the original rib fracture, leading to chest wall destruction. Some studies have reported complications after tube thoracotomy [9,10,11]. One study identified ineffective chest tube drainage, pulmonary contusion, and length of chest tube management as predictors of thoracic empyema after tube thoracotomy [11]. Based on the present findings, when persistent pneumothorax, multiple rib fractures including clavicle fractures, obesity, and long chest tube management are expected, management should be performed assuming empyema, including antibiotic prophylaxis administration.

The empyema was intractable, and the patient underwent radical surgery, while decortication of the lung was performed via posterolateral thoracostomy. The inflammatory state was more severe than expected for acute empyema, possibly due to pulmonary contusion and/or hemopneumothorax [8]. Thus, pulmonary contusions and hemopneumothorax complicated by infection may be intractable at an early stage. Plate fixation has become the mainstay of fixation for rib fractures, but the outcome of plate fixation in infected case remains controversial [12]. Therefore, chest wall repair with rib fixation was performed using suturing alone without plate fixation in our patient. Chest wall repair with suturing alone was sufficient for postoperative stabilization of the chest wall during short-term observation. In general, early surgery is recommended for cases of chest injury with chest wall instability and persistent pneumothorax [7, 13, 14]. In the present case, chest wall instability was not evident at the time of presentation, air leak was not persistent, and the patient was obese; therefore, the patient was treated conservatively, considering the risk of surgery. If there had been no chest wall instability or persistent pneumothorax, video-assisted thoracic surgery would have been considered. However, the chest wall instability worsened and was complicated by thoracic empyema; therefore, radical surgery was performed. In cases with risk factors, such as obesity, and signs of worsening, it may be better to consider antibiotic administration and surgery at an early stage due to the possibility of occult infection [3, 6, 13, 14].

The present case highlights the fact that traumatic pneumothorax can be complicated by empyema, which is a potentially intractable and life-threatening situation. As published papers indicate, antibiotic administration in tube thoracotomy can be recommended in select cases, such as persistent pneumothorax, pulmonary contusion, multiple rib fractures including clavicle fractures, obesity, and long chest tube management [3, 6], and early surgical intervention in thoracic injury can be effective if surgery is indicated [7, 13, 14]. When managing thoracic injury with pneumothorax and rib fractures, the identification of risk factors may help improve the patient’s prognosis. To ensure that the best strategy and tactics are adopted for such cases, further reporting of cases with similar physiological and anatomical findings is warranted.