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.