Air Embolism From an Intraosseous (IO) Line

IO lines are a godsend when we are faced with a patient who desperately needs access but has no veins. The tibia is generally easy to locate and the landmarks for insertion are straightforward. They are so easy to insert and use, we sometimes “set it and forget it”, in the words of infomercial guru Ron Popeil.

But complications are possible. The most common is an insertion “miss”, where the fluid then infuses into the knee joint or soft tissues of the leg. Problems can also arise when the tibia is fractured, leading to leakage into the soft tissues. Infection is extremely rare.

This photo shows the inferior vena cava of a patient with bilateral IO line insertions (black bubble at the top of the round IVC). During transport, one line was inadvertently disconnected and probably entrained some air. There was no adverse clinical effect, but if the problem is not recognized and the line closed, there could be.

Scoop and Run or Stay and Play for Trauma Care?

Scoop and run vs stay and play are traditionally EMS concepts. Do I stay at the scene to perform invasive procedures, or do I perform the minimum I can and get to the nearest hospital?

For trauma patients time is the enemy and there is a different flavor of scoop and run vs stay and play. Do I take the patient to a nearby hospital that is not a high level trauma center to stay and play, or do I scoop and run to the nearest Level I or II center?

Admissions to a group of 8 trauma centers were analyzed over a 3 year period. A total of 1112 patients were studied. Patients were divided into two groups: those who were taken directly to a Level I trauma center (76%), and those who were transferred from another hospital (24%). 

Patients who were taken to a non-trauma center first received 3 times more IV crystalloid, 12 times more blood, and were nearly 4 times more likely to die!

Obviously, the cause of this increased mortality cannot be determined from the data. The authors speculate that patients may undergo more aggressive resuscitation with crystalloid and blood at the outside hospital making them look better than they really are, and then they die. Alternatively, they may have been under-resuscitated at the outside hospital, making it more difficult to ensure survival at the trauma center.

Bottom line: this is an interesting paper, but there are a number of flaws that prevent us from mandating that all trauma patients should go directly to the trauma center. The authors never really define a “nontrauma hospital.” Does a Level III or IV center count? How did patients who stayed at the outside hospital do?

A lot of work needs to be done to add detail to this work. In the meantime, we have to trust our experienced prehospital providers to determine who really needs to go to the closest appropriate center, and what that really is.

Reference: Scoop and run to the trauma center or stay and play at the local hospital: hospital transfer’s effect on mortality. J Trauma 69(3):595-601, 2010.

Which Lacerations Can I Close?

There is always debate about which lacerations can be closed, but not a lot of literature to back it up. Here are some good rules to follow:

  • In general, close all face and scalp lacerations. They almost never get infected. Complicated ones may need extra care, debridement, or involvement of a plastic surgeon. 
  • Closing lacerations that are more than 24 hours old is risky (except for the face). They tend to be colonized with skin flora and become infected much more frequently.
  • Most other lacerations can be closed primarily within 24 hours. For the most part, it doesn’t matter what the cutting instrument was. One exception is an object that is heavily contaminated (e.g. freshly used pitchfork). Most knives don’t fall into this category. They are clean, but not sterile and the risk of infection is low.

All wounds should be inspected for foreign bodies. On occasion, this may require an xray. But remember that many foreign objects (wood, glass) are not radiopaque and will be invisible. Next, the wound should be copiously irrigated with sterile saline to flush out any small particles and reduce bacterial counts. Finally, if the edges are ragged the wound should be sharply debrided.

Antibiotics are not usually needed, since the few bacteria left will be rapidly taken care of by the patient’s immune system. If there are worries about contamination or the patient is immunocompromised, a very brief course of antibiotic is recommended. Tetanus toxoid should be given if indicated.

The most important issue is patient education. The signs and symptoms of early wound infection should be explained, and a phone number or location for followup should be clearly listed.

Bottom line: All lacerations can be safely closed within 24 hours, with a few exceptions. 

Yet Another Paper on Treating Pneumothorax With Oxygen?

Back in February, I thought I closed the door on using high inspired oxygen to try to speed up the resolution of pneumothorax (see related post below). I’ve just run across another attempt which is equally as bad!

This article was published in the Journal of Pediatric Surgery in 2000. The authors randomly divided 27 rabbits into three groups: room air, 40% O2, and 60% O2. Each was given a complete pneumothorax and received chest xrays twice a day. The average time to resolution was measured in each group.

At first glance, it appears that the higher O2 groups resolve faster. But wait, something’s fishy here! In the room air group, the complete pneumothorax went away on its own in 5 days. This doesn’t really happen in people. And in the 60% group, it disappeared in a day and a half! Miraculous!

Oh, and incidentally, a quarter of the rabbits died before completion of the study.

Bottom line: At first glance, these results sure look promising. However, they are rabbits, and they don’t act like people, let alone children! And the resolution times are unrealistic for humans. I still do not recommend the use of high inspired oxygen in an attempt to resolve a pneumothorax. Either some kind of tube is needed for larger volumes (small caliber if air only, bigger if blood is present), or it will go away on its own if the pneumothorax is small.

Related posts:

Reference: Zierold et al. Supplemental oxygen improves resolution of injury-induced pneumothorax. J Pediatric Surg 35(6):998-1001, 2000.

Radiation Exposure in Pediatric Trauma

The use of radiographic imaging in trauma patients has exploded over the past decade. A growing amount of research is looking at adult patients, but what about children?

Johns Hopkins did a one year retrospective review of radiographic imaging in kids age 14 and below. The studies performed and the estimated radiation dose was calculated for each child. A total of 719 children were studied and they underwent a total of 4603 studies:

  • CT scans – 1457 (32%)
  • Plain radiographs – 3097 (67%)
  • Fluoroscopy – 49 (1%)

CT accounted for only 32% of studies but delivered 91% of the total radiation dose. Children involved in car crashes received the highest dose of radiation (18mSv) versus burned children, who had the lowest dose (1.2 mSv). Radiation exposure increased as the injury severity increased. The average age was 8 years, which means that these children have a long time until possible side-effects emerge.

What to do? First, seriously weigh the risks and benefits of every radiographic study before you order it. If CT is not essential, do something else. The ALARA concept is key (as low as reasonably achievable):

  • Use weight-based CT protocols in order to deliver the minimum amount of radiation needed to get decent images
  • Shield all sensitive areas that are not being imaged
  • Use focused studies
  • Avoid repeat exams
  • Become knowledgeable about the effects of radiation exposure
  • Ask yourself: “What if this were my child?

Reference: Brown, et al. Diagnostic radiation exposure in pediatric trauma patients. J Trauma 2010, ahead of print.