All posts by The Trauma Pro

Emergency Intubation: ED or OR?

March 24, 2023 The Trauma Pro Leave a comment

Decades ago, intubation of trauma patients only took place in the operating room, and only anesthesiologists performed it. As the discipline of Emergency Medicine came into being in the 1980s, emergency physicians became skilled in this procedure. Occasional trauma intubations had to occur in the ED, and typically anesthesia was called for it.

As the emergency physicians became more comfortable and improved their skills, they also started intubating. I distinctly remember a paper from the time (which I unfortunately do not have a reference to) stating that ED and OR intubation were equally safe if the ED intubation field could be made to look like the OR. This thinking has become commonplace, and in most trauma centers, intubation is now provided nearly exclusively by emergency physicians. Anesthesia is called only for extremely difficult cases.

But we have all been involved in cases where the patient is severely injured, usually hypotensive, and crashes and burns during or immediately after the procedure. This is likely due to a combination of loss of sympathetic tone due to the drugs administered, increased vagal tone from instrumenting the airway, and hypovolemia.

Authors from the University of Wisconsin, University of Pennsylvania, and Johns Hopkins hypothesized that ED intubation for patients requiring urgent operation for hemorrhage control was associated with adverse outcomes. They performed a three-year registry study from the National Trauma Program Databank of patients requiring laparotomy for hemorrhage control within 60 minutes of arrival. They excluded the dead and nearly dead (DOA, ED thoracotomy) and patients with immediate indications for intubation (head, neck, or facial trauma). They compared mortality, ED dwell time, blood transfusions, and major complications between patients with ED vs. OR intubation.

Here are the factoids:

Nearly 10,000 patients from 253 Level I or II trauma centers were included in the study
About 20% of patients underwent intubation in the ED, and they were more likely to have blunt trauma mechanism and higher ISS (22 vs. 17)
Initial vital signs were not clinically significant between the ED and OR groups
Mortality in the ED group was significantly higher (17% vs. 7%), the ED dwell time was significantly longer ( 31 vs. 22 minutes), required significantly more blood transfusion (6 vs. 4 units), and had a significantly higher risk of major complications (specifically cardiac arrest, AKI, and ARDS)
There was a wide variation in the rate of ED intubation across all the hospitals. Centers with the highest rate of ED intubations were 5x more likely to intubate than the lowest rate centers. The patient case mix could not explain this difference.
The lower ED intubation rate hospitals tended to be nonprofit Level I university hospitals
Centers with high levels of hemorrhage control surgery were more likely to intubate in the OR

Bottom line: From a purely technical perspective, the old dogma about patient location not making a difference is basically true. The process of getting an airway safely into the patient and secured is equivalent wherever it is done as long as the lighting, equipment, and skill levels are equivalent.

But when one considers the physiologic aftermath of this process, things are obviously more nuanced. Actively bleeding patients are extremely challenged, down to their organ and cellular levels. Disrupting their normal compensatory mechanisms is clearly associated with a significant downside.

We should clearly distinguish the patient who needs an airway for airway’s sake or cerebral protection from one who needs to be in the OR for bleeding control. Other papers have shown that mortality increases as each minute ticks by in the hemorrhaging patient. Trauma programs need to monitor these patients and do a performance improvement deep dive into all trauma patients intubated in the ED to ensure appropriate decision-making.

Reference: Emergency Department Versus Operating Room Intubation of Patients Undergoing Immediate Hemorrhage Control Surgery. Journal of Trauma and Acute Care Surgery, Publish Ahead of Print
DOI: 10.1097/TA.0000000000003907

Tips

Management Of Penetrating Neck Trauma: The Way We Were/Are

March 20, 2023 The Trauma Pro Leave a comment

The management of penetrating injuries to the neck has changed very little over the years. Could it be time? Today, I’ll review some of the basics of classic diagnosis and treatment. In my next post, I’ll discuss an alternative way to approach it.

First, lets look at the time-honored zones of the neck. Here’s a nice diagram from EMDocs.net:

The zones are numbered in reverse, from bottom to top, and in Roman numerals.

The area below the cricoid cartilage is considered Zone I and contains many large vascular and aerodigestive structures that are relatively difficult to approach surgically. For this reason, diagnostic testing is recommended to assist in determining if an operation is actually needed and what the best surgical exposure would be. Obviously, this can only be considered in the stable patient. Unstable patients must go straight to the OR and the trauma surgeon will determine the surgical approach on the fly.

Similarly, the area above the angle of the mandible is Zone III, and is also difficult to expose. Injuries to this area may involve the distal carotid and vertebral arteries near the base of the skull, as well as the distal jugular vein. Surgical approach may require dislocation of or fracturing the mandible to get at this area. This is challenging and not that desirable, and few surgeons are familiar with the technique. For this reason, imaging is very desirable and often demonstrates that no significant injury is present. And endovascular / angiographic techniques are now available that may obviate the need for surgery.

Zone II is everything in-between the mandibular angle and cricoid cartilage. This is the surgical Easy Button. Exposure is simple and the operation is fun. In the old days, an injury to this area went straight to the OR regardless of whether there were signs or symptoms of injury. Yes, there were quite a few negative explorations. But we’ve become more selective now with the advent of improved resolution of our CT scans.

Currently, we usually follow a two-step approach to penetrating neck trauma:

Are there hard signs of injury present? These tell us that a structure that absolutely needs to be fixed has been injured. The patient should be taken directly to OR after control of the airway, if appropriate. Typical hard signs are:
1. Airway compromise
2. Active air bubbling from wound
3. Expanding or pulsatile hematoma
4. Active bleeding
5. Hematemesis
What zone is the injury in? And don’t just look at the obvious entry point. Gunshots (and long knives) may enter multiple zones. The zone then determines what happens next:
1. Zone I – CT angio of neck and chest. If positive, proceed to OR for repairs, and perform EGD and/or bronchoscopy as needed
2. Zone II – Old days: proceed to operating room for exploration, or angiogram, EGD, direct laryngoscopy, and bronchoscopy. Most chief residents chose the former. Current day: CTA of neck, followed by OR, EGD, bronchoscopy only if indicated.
3. Zone III – CT angio of the neck. If positive, consider angiography/endovascular consultation vs operation.

Changes from old days to more current thinking have been made possible by improvements in speed and resolution of our CT scanners. But why can’t we take this another step forward and streamline this process even more? I’ll propose some changes in my next post!

Reference: Western Trauma Association Critical Decisions in Trauma:
Penetrating neck trauma. J Trauma 75(6):936-940, 2013.

General

Flying Or Diving After Traumatic Pneumothorax: Part 2

March 17, 2023 The Trauma Pro Leave a comment

In my last post, I wrote about the accepted management of and delay in flying due to traumatic pneumothorax. I republished the post because of the publication of a paper from Oregon Health Science University in Portland. The authors specifically tried to assess timing of chest tube removal and long-distance flight, and to measure the risk of pneumothorax recurrence or other complications.

The authors performed a retrospective review of a series of military patients who had sustained chest injuries that were treated with chest tubes over a 5 year period from 2008 to 2012. After tube removal and a pneumothorax-free period of at least 24 hours (by chest x-ray), the patients were then transported by air from the military theater back to the United States.

Here are the factoids:

Of 517 patients screened in the military trauma registry database, only 73 were available for study after applying exclusion criteria
Subjects were predominantly young and male, as one would expect from the injured military population, and 74% were injured by a penetrating mechanism
Median time that the chest tube was in place was 4 days, and median time from tube removal to flight was 2.5 days
All patients had post-flight documentation available for review, but only half (37) had in-flight documentation available
Nearly half (40%) had positive pressure ventilation in place during the flight
Five patients had “in-flight medical concerns” (4 were ventilated), but none were related to the pneumothorax. The four ventilated patients had ventilator issues, the non-vented patient had “self-limited discomfort without evidence of respiratory distress.”
None of the subjects developed a recurrent pneumothorax, either post-flight or over the following 30 days

The authors conclude that air travel after tube removal and a 24-72 hour observation period “appears safe.”

Bottom line: Not so fast! This is yet another small, retrospective study making grand claims. The study group is a very unique population: healthy, fit young men with penetrating injury. Your average civilian trauma patient is older, less healthy, and usually has a blunt mechanism with multiple rib fractures. In-flight documentation was not available in half of the cases. And a full medical team was present on the aircraft had a problem actually occurred.

Contrast this with a civilian patient on a commercial aircraft with very limited medical equipment and expertise on board. What could go wrong? I definitely do not recommend changing our practice on these patients yet based on this one paper. Until we have better guidance (more good papers) stick to the usual wait time to ensure a safe flight for your patient.

Reference: Trauma patients are safe to fly 72 hours after tube thoracostomy removal. J Trauma, published ahead of print, May 18 2018.

Thorax

Flying Or Diving After Traumatic Pneumothorax: Part 1

March 15, 2023 The Trauma Pro Leave a comment

Today, I’m dusting off an old post on flying and diving after pneumothorax. This shows the thinking up until a few years ago. In my next post, I’ll write about a more recent paper that suggests that we can shorten the “no-fly” time considerably.

Hint: no changes to the diving recommendations. One pneumothorax is likely to ground you forever. (pardon the pun)

Patients who have sustained a traumatic pneumothorax occasionally ask how soon they can fly in an airplane or scuba dive after they are discharged. What’s the right answer?

The basic problem concerns Boyle’s Law (remember that from high school?). The volume of a gas varies inversely with the barometric pressure. So the lower the pressure, the larger the volume of gas becomes. Most of us hang out close to sea level, so this is not an issue. But for flyers or divers, it may be.

Flying

Helicopters typically fly only one to two thousand feet above the ground, so the air pressure is about the same as standing on the earth. However, flying in a commercial airliner is different. Even though the aircraft may cruise at 30,000+ feet, the inside of the cabin remains considerably lower though not at sea level. Typically, the cabin altitude goes up to about 8,000 to 9,000 feet. Using Boyle’s law, any volume of gas (say, a pneumothorax in your chest) will increase by about a third on a commercial flight.

The physiologic effect of this increase depends upon the patient. They may never know anything is happening if they are young and fit. But if they are elderly and/or have a limited pulmonary reserve, it may compromise enough lung function to make them symptomatic. And having a medical problem in an aluminum tube at 30,000 feet is never good.

Commercial guidelines for travel after pneumothorax range from 2-6 weeks. The Aerospace Medical Association published guidelines that state that 2-3 weeks is acceptable. The Orlando Regional Medical Center reviewed the literature and devised a practice guideline with a single Level 2 recommendation that commercial air travel is safe 2 weeks after resolution of the pneumothorax, an that a chest x-ray should be obtained immediately before travel to confirm resolution.

Diving

Diving would seem to be pretty safe, right? Any pneumothorax would just shrink while the diver was at depth, then re-expand to the original size when he or she surfaces, right?

Not so fast. You are forgetting why the pneumothorax was there in the first place. The lung was injured, most likely via tearing it, penetration by something sharp, or popping a bleb. If the injured area has not completely healed, then air may begin to escape through it again. And since the air used in scuba diving is delivered under pressure, this could result in a tension pneumothorax. This is disastrous underwater!

Most injuries leading to pneumothorax heal completely. However, if there are bone spicules stuck in the lung or more complicated parenchymal injuries from penetrating injury, they may never completely heal. This makes the diver susceptible to a tension pneumothorax anytime they use their regulator.

Bottom line: Most patients can safely travel on commercial aircraft 2 weeks after resolution of pneumothorax. Ideally, a chest xray should be obtained shortly before travel to confirm that it is gone. Helicopter travel is okay at any time, since they typically fly at 1,500 feet or less.

Divers should see a physician trained in dive medicine to evaluate their injury and imaging prior to making another dive.

Tomorrow: new info on flying after pneumothorax

References:

Divers Alert Network – Pneumothorax – click to download
Practice Guideline, Orlando Regional Medical Center. Air travel following traumatic pneumothorax. October 2009.
Medical Guidelines for Airline Travel, 2nd edition. Aerospace Medical Association. Aviation, Space, and Environmental Medicine 74(5) Section II Supplement, May 2003.

Home of the Trauma Professional's Blog