DISCUSSION

Studies in the literature recommend that there is no need to routinely perform a chest X-ray after the removal of a chest drain following cardiac or thoracic surgery. Diverse patient populations undergoing different cardiac and thoracic surgeries have demonstrated the incidence of pneumothorax that requires intervention after removal of chest drain is low and it is highly correlated with the development of clinical symptoms. Approximately 1-2% of patients would require re-intervention after the chest drain removal, with the exception of the adult thoracic surgical population, which may be up to 10% of the patients. The high incidence could possibly be contributed by the preexisting pulmonary pathology and complex physiological changes within the pleural space associated with the thoracic surgical procedures.1
It was previously thought the paediatric population might develop a higher rate of pneumothorax occurrence since young children are unlikely to be able to follow breathing commands during the chest drain removal.20However, it is not the case when a large study with more than 11,000 paediatric patients in cardiac surgery demonstrated the incidence of pneumothorax as less than 1%.7Nevertheless, a good removal technique is essential to reduce the rate of complications.20
Current literature agrees that performing a chest X-ray is only necessary if a patient develops respiratory or cardiovascular symptoms after the removal of the chest drain given that most clinically significant pneumothorax will eventually develop clinical symptoms. Omitting a chest X-ray will significantly reduce the healthcare cost1,12,14,18,19, as well as radiation exposure in paediatric patients.12Moreover, routine chest X-rays lead to additional subsequent chest X-rays without the further need for intervention.2,14,18
On the other hand, a clinically significant pneumothorax might develop after the removal of the chest drain despite the lack of symptoms. Especially in very young patients, who are not able to communicate, it could be concerning that a moderate or large pneumothorax may not exhibit clinical symptoms in the context of a lack of good respiratory or cardiovascular physiological reserve, despite very few of them requiring subsequent intervention.7Assessment of clinical symptoms solely might not be sufficient, and subgroups of patients with risk factors should be identified to acquire chest X-rays following the removal of the chest drain.5,7Nonetheless, a greater majority of studies reinforce the fact that routine use of chest X-rays can be eliminated without compromising patient safety.
An alternative to obtaining a chest X-ray after the removal of a drain is bedside ultrasound. Despite overall low sensitivity and specificity compared to X-rays, the bedside ultrasound is highly accurate in identifying a clinically significant pneumothorax.21It is safe, has no ionising radiation, has lower cost compared to X-rays, and has rapid instant interpretation compared to ordering, obtaining and interpreting a chest X-ray. It is reproducible and requires minimum experience to detect pneumothorax, with the benefit of detecting further diagnoses such as pleural effusion and pericardial effusion.15Yet, the use of ultrasound could be limited by subjective interpretation of findings depending on the experience of the operator, postoperative surgical dressings, and anatomical and physiological changes, especially after thoracic surgery. In spite of the limitations, an overall low incidence of pneumothorax after chest drain removal would further favour the use of bedside ultrasound instead of chest X-rays.