Thursday, 15 November 2012
All about chest tubes
Of all the interventions we perform, chest tube insertion is one of the most dangerous, complicated and misunderstood. Today I'll discuss not only the myths, but also some unfortunate realities that we must understand when we undertake this procedure.
Myth # 1
Bigger is better
I'm pretty sure we've all been told, partially thanks to ATLS, that we better put a 36 or 40 French chest tube in during trauma, otherwise the blood will clog up the tube and drainage will cease. Wrong, wrong, wrong!
This prospective, non randomized trial of trauma patients over a 3 year period from 2007-2010 compared small (28-32 French) with large (36-40 French) chest tubes. The operator chose tube size, and sicker patients got bigger tubes (More ISS >25, GCS <8, sBP <90, (all p<0.01) for large chest tube group) However, there was no difference in thoracic trauma pathology between the two groups (eg. flail chest, pulmonary contusions, PTX, pneumomediastinum, etc.)
Overall, there was no difference in the rate of complications between the two groups. This includes pneumonia, empyema and retained hemothorax. Further, there was no difference in interventions required for retained hemothorax (Additional chest tube insertion, intrapleural throombolysis, IR guided catheter insertion, VATS and thoracotomy)
When adjusted for ISS, GCS and sBP, there was still no difference between the two groups, with respect to complication rates or interventions for retained hemothorax.
When pneumothoraces were analyzed separately, there was no difference in rate of complications or requirement for further intervention in this group either.
The second hypothesis of this study was that bigger tubes are more painful, and a visual analogue scale was used to rate patient pain. There was no difference in VAS scores between the small and large chest tube groups.
Bottom Line: Any tube that is at least 28 French is suitable for draining a chest.
Although it might not hurt less than a larger tube, it may still pass through the intercostal space a little more easily, so go ahead with those smaller tubes. The logical next question is: Are tubes smaller than 28 French adequate? That remains to be studied.
Directing the chest tube. ie: Up for air, down for blood.
Every medical student/resident is asked this question repeatedly throughout their training. "Where would you put the tube for a hemothorax? What about a pneumothorax?" The answers is always posterobasal for fluid and apical for air, right?
2 things about this myth. First, once the tube gets inside the chest, our ability to direct it is poor. Second, as long as you are in the pleural space, you'll be fine. It is a closed system and you have suction. The fluid will drain regardless. You may still have complications, but it's not because you put the tube in the apex of a hemothorax.
More important than directing the chest tube is ensuring it's in the pleural space, not advancing when you meet resistance and not causing any other complications.
There is a BestBets on this topic which can be found here. There really isn't great data on this, so it is more of a physics myth than anything else.
Complications of chest tubes - This is not a myth, this is for real.
This is one critical point for all of us, but especially for residents inserting chest tubes.
The morbidity associated with chest tube insertions is astronomical! About 25-30% of chest tube insertions have a complication, regardless of who inserts them. A 2012 AAST study looking at post-traumatic empyema rates in major trauma centers is 27%. That is crazy.
However, as an EM resident, I was disappointed to read this article that suggests EM residents may be the worst of all. Really it's only a trend toward significance, and a retrospective study, but I'm still a bit sad to read it.
We have to do something to get these rates of complications down.
Use of antibiotic prophylaxis when inserting chest tubes is a topic of controversy. EAST (The Eastern Association for the Surgery of Trauma) published a guideline in 2000 suggesting antibiotic prophylaxis for chest tube insertion. More recently, this meta-analysis reviewing antibiotic prophylaxis was published in 2012.
For penetrating trauma, I would say that at least a single dose of antibiotic (1st gen cephalosporin) should be given at the time of insertion, if time and resources allow. This results in reduced rates of empyema and pneumonia, which in turn affects hospital and ICU LOS.
For blunt trauma, which is the majority of what we see in Canada, no statistically significant reduction in infectious complications was found, and you may choose to withhold antibiotics in this group.
In all cases, duration of therapy is controversial. It appears that short term (single dose or 24 hours) is equally effective as prolonged antibiotics (until time of chest tube removal).
Bottom line: Our rates of post-chest tube complications (empyema and pneumonia) are ridiculously high, even in major trauma centers. A single dose of cefazolin at the time of chest tube insertion is a pretty benign intervention, and in my opinion warranted, particularly in penetrating trauma.
I'm curious who is giving antibiotics and if so, is it single dose, 24 hours, or longer?
1)Any chest tube at least 28 French is suitable for traumatic hemo/pneumothorax.
2)Get the tube in the pleural space but direction doesn't matter.
3)Complications of chest tubes are exceedingly high. Give a single dose of peri-procedure antibiotics (particularly in penetrating trauma) and use sterile technique.
Until next time, I'll be standing on the corner, mindin' my own business.
References and some chest tube links from people much more intelligent than me:
Own the chest tube with Chris Nickson at Life in the Fast Lane
Michael McGonigal's Trauma Professionals Blog has some great videos and posts about chest tubes as well.
Eastern Association of Surgeons for Trauma (EAST) Guidelines for Hemothorax and Occult PTX can be found here.
EAST Guideline on antibiotic prophylaxis for tube thoracostomy can be found for free here.
This is the reference. J Trauma. 48(4): 758-759, April 2000.
2012 Meta-analysis for antibiotic prophylaxis
Bosman A, de Jong MB, Debeij J, van den Broek PJ, Schipper IB. Br J Surg. 2012 Apr;99(4):506-13
Chest tubes: Does Size Matter
Inaba, K et al. J Trauma 72(2):422-427, 2012.
Post-traumatic chest tube empyema rates
J Trauma 73(3):752-757, 2012.