All posts by TheTraumaPro

Another Way To Treat Tension Pneumothorax

Kenji Inaba and colleagues have done a lot of work on tension pneumothorax (tPTX) in the past few years. They’ve looked for the best devices and the best positions on the chest to quickly and effectively treat this emergency. Now, they’ve published a study on using what looks like a “better mousetrap” for relieving tension physiology.

Previous work from this lab has shown that up to a quarter of needle thoracostomies fail within 5 minutes due to mechanical reasons. This leaves a small window for insertion of the real chest tube. And even though much of the pressure may be relieved, a significant amount of air may be left in the chest, impeding recovery from PEA arrest.

They looked at the use of a 5mm laparoscopy port for relief of tension pneumothorax in Yorkshire swine. The exact size of the pigs was not listed, but these animals weigh 25 pounds at 6 weeks of age, and the pictures in the article show a reasonable sized animal. I’m not sure they were 70kg, though.

Here are the factoids:

  • Five animals were used, and 30 episodes of tPTX and 27 episodes of PEA arrest from tPTX
  • Tension pneumothorax was created by insufflating the chest with CO2 using a 10mm laparoscopic trocar
  • tPTX was completely relieved by insertion of the 5mm trocar in 100% of trials, with all physiologic measures returning to baseline within 1 minute
  • Circulation was restored to normal within 30 seconds in 100% of trials
  • There was no damage to heart or lung from trocar placement in any of the 5 animals

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Bottom line: Once again, Inaba and crew have added some interesting tidbits to our knowledge base. You already know I’m not a fan of animal studies like this, but this one lays the ground work for some work in humans. We still need to know how the “usual American body habitus” will affect the use of this device. The only downside is the expense of the trocar, which is a lot more than a simple long needle. But if it is as efficacious in humans as it is in pigs, it may be worth it!

Related posts:

Reference: Standard laparoscopic trocars for the treatment of tension pneumothorax: A superior alternative to needle decompression. J Trauma 77(1):170-175, 2014.

Procedural Complications: Residents vs Advanced Practice Providers

With the implementation of resident work hour restrictions 10 years ago, resident participation in clinical care has declined. In order to make up for this loss of clinical manpower and expertise, many hospitals have added advanced clinical providers (ACPs, nurse practitioners and physician assistants). These ACPs are being given more and more advanced responsibilities, in all clinical settings. This includes performing invasive procedures on critically ill patients. 

A recent study from Carolinas Medical Center in Charlotte NC compared complication rates for invasive procedures performed by ACPs vs residents in a Level I trauma center setting.

A one year retrospective study was carried out. Here are the factoids:

  • Residents were either surgery or emergency medicine PGY2s
  • ACPs and residents underwent an orientation and animal- or simulation-based training in procedures
  • All procedures were supervised by an attending physician
  • Arterial lines, central venous lines, chest tubes, percutaneous endoscopic gastrostomy, tracheostomy, and broncho-alveolar lavage performances were studied
  • Residents performed 1020 procedures and had 21 complications (2%)
  • ACPs performed 555 procedures and had 11 complications (2%)
  • ICU and hospital length of stay, and mortality rates were no different between the groups

Bottom line: Resident and ACP performance of invasive procedures is comparable. As residents become less available for these procedures, ACPs can (and will) be hired to  take their place. Although this is great news for hospitals that need manpower to assist their surgeons and emergency physicians, it should be another wakeup call for training programs and educators to show that resident education will continue to degrade.

Related posts:

Reference: Comparison of procedural complications between resident physicians and advanced clinical providers. J Trauma 77(1):143-147, 2014.

The Newest Trauma MedEd Newsletter Is Available!

After taking a travel break last month, it’s back! The latest edition of
the Trauma MedEd newsletter is now available for download. The subject is Abdomen. Included are articles on:

– How to close an abdominal stab laparoscopically
– FAST is FAST and FAST is last!
– FAST exam in children
– Performance improvement for FAST
– DPL: a dying art?
– Less morbidity from negative trauma laparotomy?

The web link to this month’s issue is http://bit.ly/TME-06-2014.

You can view and download back issues at http://www.TraumaMedEd.com

Liver Function Testing After Hepatic Injury

The liver is one of the two most commonly injured solid organs after blunt trauma. There are a variety of ways to manage solid organ injury, and many trauma centers are adopting solid organ injury protocols to streamline and improve care. I am occasionally asked whether there is a place for liver function testing after hepatic injury. 

In a previous post (see below), I cited some old literature refuting this idea. A more recent paper has now tried to answer this question. They retrospectively reviewed 3 years of data on patients admitted to a large hospital in Jiangsu, China. Only patients with blunt liver injury were included. They were interested to know if liver function testing helped identify the presence and severity of injury.

Here are the factoids:

  • 182 patients who had blunt abdominal injury and liver function testing were identified in their registry (AST, ALT, GGT, Alk PHos, LDH, bili)
  • 90 patients had liver injury and 92 did not
  • Grade of liver injury was fairly evenly distributed, with a few less grade IV and V
  • Elevated LFTs accurately predicted the presence of a liver injury. ALT > 57 U/L was the most accurate predictor.
  • There was no correlation between LFT values and severity of liver injury

Bottom line: Basically, routine liver function testing after blunt abdominal trauma is a waste of time. And obtaining LFTs after known liver injury is an even greater waste of time. You know your patient has the injury, and you know the grade from the CT scan you obtained (hopefully). And from personal experience, there is absolutely no value in “trending” liver functions to see how the liver is healing. If the patient develops an unexpected clinical finding at some point (new pain, jaundice, fever), then you may wish to order laboratory or imaging studies to help determine if a complication is developing.

Related posts:

Reference: Role of elevated liver transaminase levels in the diagnosis of blunt liver injury after blunt abdominal trauma. Experimental and Therapeutic Medicine 4(2):255-260, 2012.

The EMS Second IV In Trauma

One of the critical maneuvers that EMS providers perform is establishing initial vascular access. This IV is important for administering medications and for initiating volume resuscitation in trauma patients. Prehospital Trauma Life Support guidelines state that every trauma patient should receive two large bore IV lines. But is this really necessary?

The upside of having two IVs in the field is that the EMS provider can give lots of volume. However, a growing body of literature tells us that pushing systolic blood pressure up to “normal” levels in people (or animals) with an uncontrolled source of bleeding can increase mortality and hasten coagulopathy.

The downside of placing two lines is that it is challenging in a moving rig, sterility is difficult to maintain, and the chance of a needlestick exposure is doubled. So is it worth it?

A group at UMDNJ New Brunswick did a retrospective review of 320 trauma patients they received over a one year period who had IV lines established in the field. They found that, as expected, patients with two IVs received more fluid (average 348ml) before arriving at the hospital. There was no increase in systolic blood pressure, but there was a significant increase in diastolic pressure with two lines. The reason for this odd finding is not clear. There was no difference in the ultimate ISS calculated, or in mortality or readmission.

Bottom line: This study is limited by its design. However, it implies that the second field IV is not very useful. The amount of extra fluid infused was relatively small, not nearly enough to trigger additional bleeding or coagulopathy. So if another IV does not deliver significant additional fluid and could be harmful even if it did, it’s probably not useful. Prehospital standards organizations should critically look at this old dogma to see if it should be modified.

Reference:

  • Study of placing a second intravenous line in trauma. Prehospital Emerg Care 15:208-213, 2011.