Discussion
We have presented the results of cohort studies that compare early
versus late chest tube removal following open-heart surgery. We judged
three studies to be high quality15,22,23, and two
studies to be of moderate quality.11,24 Articles with
a relatively lower quality level emphasized on late chest tube removal.
There is no sufficient evidence on the timing of chest tube removal
after open-heart surgery. Hence, some authors suggest removing them
after 24 hours postoperative and some authors recommended to remove the
chest tube after 48 hours postoperative.11,15,22-24
Three studies from the studies reviewed showed that early chest tube
removal does not increase risk of pleural
effusion.15,22,23. But two studies have stated that
there is a link between early chest tube removal and pleural
effusion.11,24
This variation in results is probably since that in the first three
studies that recommended early chest tube removal, the timeframe for
early in these studies were 24 hours and for late 48 hours while, this
is different in the Andersen et al. (2015) study and the time to early
chest tube removal in this study is up to 14 hours, which is shorter and
earlier than the first three studies and maybe the reason for more
occurrence pleural effusion. On the other hand, the timeframe for group
late Chest tube removal of Andersen et al. (2015) study that
approximately 24 hours, is consistent with timeframe of the early chest
tube removal group in the three studies agree with the early chest tube
removal in this systematic review. In this group of Andersen et al.
(2015) study less pleural effusion has been observed which is in line
with the results of the group early chest tube removal in three studies
agrees with the early chest tube removal.
A recent systematic review of a similar issue in our study has shown
that other properties, such as the chemical composition of pleural
fluid, can be a predictor for the timing of chest tube removal. Also,
the removal of chest tubes can occur only when the fluid is completely
serosanguineous and lacks blood and chylous.14
According to our query, no intervention study was found on this issue
and if available, it appears to be very low or not in English. Due to
the growing perspective of evidence-based treatment, interventional
studies are referred to as the gold standard for evaluating the
effectiveness of an intervention or treatment.25Therefore, it is necessary to conduct interventional studies with high
validity and controlled conditions on this topic to suggest the precise
time to remove the chest tube in patients undergoing open-heart surgery.
It is also recommended that writing a guideline can help improve the
treatment process for these patients.
Another issue to consider is the diagnosis of pleural effusion after
chest tube removal. In the studies investigated in our review, there was
a disagreement that some study used Chest X-ray as a diagnostic test and
some used CT scans. Even in the Abramov study, which used both
diagnostic tests to detect pleural effusion, there were variations in
results.15,16 Therefore, further research is needed to
clarify this issue.
Because of the complexity of the issue and the relevance of multiple
factors to pleural effusion, it is also recommended to look for other
indicators to determine when to remove the chest tube. However, it has
been suggested that the occurrence of pleural effusion may vary
depending on the geographical location of
individuals.26,27