Category Archives: Thorax

Complications, Thorax

Retained Hemothorax Part 1: Lytics

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In my last pair of posts, we reviewed chest tube management. Now let’s dive into hemothorax. This gets a little complicated, because a chest tube doesn’t always do what it’s supposed to when it comes to blood and possible blood clots.

Hemothorax is a common complication of chest trauma, occurring in about one third of cases. It is commonly treated with a chest tube, which usually takes care of the problem. But in a few cases some blood remains, which can result in an entrapped lung or empyema.

There are several management options. Historically, these patients underwent thoracotomy to peel out the fibrinous collection stuck to lung and chest wall. This has given way to the more humane VATS procedure (video assisted thoracoscopic surgery) which accomplishes the same thing using a scope. In some cases, another tube can be inserted, sometimes under CT guidance, to try to drain the blood.

So what about lytics? It’s fibrin, right? So why not just dissolve it with tissue plasminogen activator (tPA)? There have been very few studies published over the years. The most recent was in 2014. I’ll review it today, and another tomorrow. Finally, I’ll give you my thoughts on the best way to deal with retained hemothorax.

Here are the factoids:

  • This was a single center, retrospective review of data from 1.5 years beginning in 2009
  • A total of seven patients were identified, and most had hemothorax due to rib fractures. Three presented immediately after their injury, 4 were delayed.
  • Median time from injury to chest tube placement was 11 days
  • Median time the chest tube was in place was 13 days, with an average hospital stay of 14 days
  • Patients received 1 to 5 treatments, averaging 24mg per dose
  • There was one death in the group, unrelated to TPA treatment
  • No patient “required” VATS, but one underwent thoracotomy, which turned out to be for a malignancy

Bottom line: The authors conclude that tPA use for busting retained hemothorax is both safe and effective. Really? With only seven patients? The biggest problem with this study is that it uses old, retrospective data. We have no idea why these patients were selected for tPA in this 5-year old cohort of patients. Why did it take so long to put in chest tubes? Why did the chest tubes stay in so long? Maybe this is why they were in the hospital so long?

Plus, tPA is expensive. A 100mg vial runs about $6000. Does repeatedly using an expensive drug and keeping a patient in the hospital an extra week or so make financial sense? So it better work damn well, and this small series doesn’t demonstrate that.

Tomorrow, I’ll look at the next most recent paper on the topic, from way back in 2004.

Reference: Evaluation of chest tube administration of tissue plasminogen activator to treat retained hemothorax. Am J Surg 267(6):960-963, 2014.

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Thorax

Practice Guideline: Chest Tube Management (Part 2)

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In my last post, I went over the rationale for developing a practice guideline for something as simple and lowly as chest tube management. Today, I’m posting the details of the guideline that’t been in use at my hospital for the past 15 years. I’ve updated it to reflect two lessons learned from actually using it.

Here’s an image of the practice guideline. Click to open a full-size copy in a new window:

Here are some key points:

  • Note the decision tree format. This eliminates uncertainty so that the clinician can stick to the script. There are no hedge words like “consider” used. Just real verbs.
  • We found that hospital length of stay improved when we changed the three parameters from daily monitoring to three consecutive shifts. We are prepared to pull the tube on any shift, not just during the day time. And it also allows this part of the guideline to be nursing driven. They remind the surgeons that criteria are met so we can immediately remove the tube.
  • Water seal is only used if there was an air leak at some point. This allows us to detect a slow ongoing leak that may not be present during our brief inspection of the system on rounds.
  • The American College of Surgeons Committee on Trauma expects trauma centers to monitor compliance with at least some of their guidelines. This one makes it easy for a PI nurse or other personnel to do so.
  • The first of the “new” parts of this guideline is: putting a 7 day cap on failure due to tube output greater than 150cc per three shifts. At that point, the infectious risks of keeping a tube in begin to outweigh its efficacy. Typically, a small effusion may appear the day following removal, then resolves shortly.
  • The second “new” part is moving to VATS early if it is clear that there is visible hemothorax that is not being drained by the system. Some centers may want to try irrigation or lytics, but the data for this is not great. I’ll republish my posts on this over the next two days.

Click here to download a copy of this practice guideline for adults.

Click here to download the pediatric chest tube practice guideline.

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Thorax

Practice Guideline: Chest Tube Management (Part 1)

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I’m devoting the next series of posts to revisiting the management of hemo- and/or pneumothorax. These clinical issues are some of the most common sources of variability in how trauma professionals approach them. Let’s start with the seemingly simple chore of managing a lowly chest tube.

Management of chest tubes is one of those clinical situations that are just perfect for practice guideline development: commonly encountered, with lots of variability between trauma professionals. There are lots of potential areas for variation:

  • How long should the tube stay in?
  • What criteria should be used to determine when to pull it?
  • Water seal or no?
  • When should followup x-rays be done?

Every one of these questions will have a very real impact on that patient’s length of stay and potential for complications.

We developed a chest tube clinical practice guideline (CPG) at Regions Hospital way back in 2004! Of course, there was little literature available to guide us in answering the questions listed above. So we had to use the clinical experience and judgment of the trauma faculty to settle on a protocol that all were comfortable with.

Ultimately, we answered the questions like this:

  • The tube stays in until three specific criteria are met
  • The criteria are: <150 cc drainage over 3 shifts, no air leak, and no residual pneumothorax (or at least a small, stable one)
  • Use of water seal is predicated on whether there was ever an air leak
  • An x-ray is obtained to determine whether any significant pneumo- or hemothorax is present prior to pulling the tube, and 6 hours after pulling it

This CPG has been in effect for over 15 years with excellent results and dramatically shortened lengths of stay.  However, as with any good practice guideline, it needs occasional updates to stay abreast of new research literature or clinical experiences. We recognized that occasional patients had excessive drainage for an extended period of time. This led us to limit the length of time the tube was in to seven days. And we also noted that a few patients had visible hemothorax on their pre-pull imaging. These patients were very likely to return with clinical symptoms of lung entrapment, so we added a decision point to consider VATS at the end of the protocol.

I’ll share the full protocol tomorrow and provide a downloadable copy that you can modify for your own center. I’ll also give a little more commentary on the rationale for the key decision points in this CPG.

Related posts:

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Abstracts, Thorax

Best Of AAST 2021: Chest Tube Based On Pneumothorax Size

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How big is too big? That has been the question for a long time as it applies to pneumothorax and chest tubes. For many, it is a math problem that takes into account the appearance on chest x-ray, the physiology of the patient, and their ability to tolerate the pneumothorax based on any pre-existing medical conditions.

The group at Froedtert in Milwaukee has been trying to make this decision a bit more objective. They introduced the concept of CT based size measurement using a 35mm threshold at this very meeting three years ago. Read my review here. My criticisms at the time centered around the need to get a CT scan for diagnosis and their subjective definition of a failure requiring chest tube insertion. The abstract never did make it to publication.

The authors are back now with a follow-on study. This time, they made a rule that any pneumothorax less than 35mm from the chest wall would be observed without tube placement. The performed a retrospective review of their experience and divided it into two time periods: 2015-2016, before the new rule, and 2018-2019, after the new rule. They excluded any chest tubes inserted before the scan was performed, those that included a sizable hemothorax, and patients placed on a ventilator or who died.

Here are the factoids:

  • There were 93 patients in the early period and 154 in the later period
  • Chest tube use significantly declined from 20% to 10% between the two periods
  • Compliance with the rule significantly increased from 82% to 92%
  • There was no difference in length of stay, complications, or death
  • Observation failure was marginally less in the later period, and statistical significance depends on what method you use to calculate it
  • Patients in the later group were 2x more likely to be observed (by regression analysis)

The authors concluded that the 35mm rule resulted in a two-fold increase in observation and decreased the number of unnecessary CT scans.

Bottom line: I still have a few issues with this series of abstracts. First, decision to insert a chest tube requires a CT scan in a patient with a pneumothorax. This seems like extra radiation for patients who may not otherwise fit any of the usual blunt imaging criteria. And, like their 2018 abstract, there is no objective criteria for failure requiring tube insertion. So the number of insertions can potentially be quite subjective based on the whims of the individual surgeon.

What this abstract really shows is that compliance with the new rule increased, and there were no obvious complications from its use. The other numbers (chest tube insertions, observation failure) are just too subjective to learn much from.

Here are my questions for the presenter and authors:

  • Why was there such a large increase in the number of subjects for two identical-length time periods? Both were two years long, yet there were two-thirds more patients in the later period. Did your trauma center volumes go up that much? If not, could this represent some sort of selection bias that might change your numbers?
  • You concluded that your new rule decreased the number of “unnecessary” CT scans? How so? It looks like you are using more of them!
  • Do you routinely get a chest CT on all your patients with pneumothorax? Seems like a lot of radiation just to decide whether or not to put a tube in.
  • How do you manage a pneumothorax found on chest x-ray? Must they get a CT? Or are you willing to watch them and follow with serial x-rays?
  • How do you decide to take out the chest tube? Hopefully not another scan!

There should be some very interesting discussion of this abstract!

Reference: THE 35-MM RULE TO GUIDE PNEUMOTHORAX MANAGEMENT: INCREASES APPROPRIATE OBSERVATION AND DECREASES UNNECESARY CHEST TUBES. AAST 2021, Oral abstract #56.

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Abstracts, Thorax

Best Of AAST 2021: Liposomal Bupivacaine For Rib Fractures

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The mainstays of rib fracture management are pain control and pulmonary toilet. The pain part of the equation can be managed in many ways, using topical, oral, IV, and injectable medications.

Rib blocks have been a mainstay for achieving some degree of local pain control. Classically, xylocaine was injected in the area around the costal nerve at or proximal to the fracture site. Then we found that if we combined the anesthetic agent with epinephrine, we could prolong the effect. New, longer-acting agents came around, and we could achieve a longer duration of action.

Then there is the new kid on the block: liposomal bupivacaine, also known as Exparel in the US.  The manufacturer was able to take molecules of bupivacaine and encapsulate them in a lipid membrane. When injected, these little liposomes slowly release their cargo, with a more prolonged anesthetic effect. Allegedly.

Sounds great! But does it work? The group at University of Cincinnati designed a prospective, double-blinded, randomized placebo control study of liposomal bupivacaine vs saline injection for pain control in up to six rib fractures. Subjects had significant injury as measured by their inability to achieve at least 50% of the desired inspiratory capacity. The authors monitored a number of respiratory parameters, as well as the pain score.

Here are the factoids:

  • Two cohorts of 50 patients were recruited, one received liposomal bupivacaine in up to six rib fractures, and the other received saline injections
  • The bupivacaine group achieved higher incentive spirometry volumes over the first two days, by about 200 cc
  • There was no change in daily pain scores in either group
  • Both groups showed a similar decrease in opioid use over time
  • Hospital and ICU lengths of stay were the same, and there were no complications or adverse events

Bottom line: Hmm. What’s going on here? There is a moderate amount of literature out there that does indicate a positive effect from liposomal bupivacaine in other conditions. But there are also some blinded, randomized studies that fail as well. So there are three possibilities:

  1. Liposomal bupivacaine isn’t a panacea, and works better in some situations than others
  2. This study failed to show a real difference for some reason
  3. A combination of both

This is a relatively small study, and the authors were not able to share their power analysis. They did not state if the spirometry volumes were significantly different, although I’m not sure 200 cc is clinically relevant. Maybe. But pain scores remained similar and opioid use declined as expected in both. 

These kinds of studies can be important. The difference in cost between injecting liposomal bupivacaine ($19 / ml) vs regular bupivacaine (10 cents / ml) vs saline/nothing (free) is striking. The premium price for the liposomal form needs to have a clear benefit or a cheaper product should be used.

Here are my questions for the presenter and authors:

  • Was your study big enough to show a result? Show us your power analysis.
  • How significant was the incentive spirometry result. Was the difference clinically noticeable?
  • What is your takeaway for this study? Your conclusion parrots the results. What will you do differently now, if anything?

Reference: INTERCOSTAL LIPOSOMAL BUPIVACAINE INJECTION FOR
RIB FRACTURES. AAST 2021, Oral abstract #20.

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