Does oxygen therapy increase the resolution rate of primary spontaneous pneumothorax?

BACKGROUND: Patients with small pneumothoraces are usually treated with oxygen therapy. However, evidence that oxygen therapy increases resolution rate is based on small populations with secondary spontaneous pneumothorax. Therefore, this study aimed to confirm whether oxygen therapy increases the resolution rate of primary spontaneous pneumothorax (PSP).

METHODS: We retrospectively reviewed records of patients with PSP who had undergone outpatient observation (room air group) and those who were admitted for oxygen therapy (O2 group) between March 2005 and February 2016. The initial chest posteroanterior (PA) radiograph was compared with the last chest PA radiograph before the pneumothorax disappeared. The size of the pneumothorax was measured using the Collins' method.

RESULTS: A total of 175 episodes were identified in 160 patients. Of these, 128 episodes (73.1%) occurred in patients in the O2 group. The mean age was 19.24±4.74 years. The mean initial size of the pneumothorax was smaller in the room air group (23.32%±7.00% vs . 20.26%±6.78%, P=0.011). The resolution rate was higher in the O2 group [(4.27%±1.97%) vs . (2.06%±0.97%)/day, P<0.001]. The initial size of the pneumothorax, time interval between radiographs, and use of oxygen therapy were significantly associated with the resolution rate in multivariate analysis.

CONCLUSIONS: Oxygen therapy increases the resolution rate of PSP. However, routine use of oxygen therapy in patients with small pneumothoraces should be considered more carefully. Well-controlled prospective studies are required to confirm the indication of oxygen therapy.