Trauma Tuesday: Handlebar Injuries

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Case: Pediatric patient arrives after being overzealous on his bicycle with the following wound.

The first thing you do is recognize the sign. The second thing you do is ask to look at a video of what happened.

What we see above is the handlebar sign. It can present either as a longitudinal pattern of the bicycle handlebars strike the abdomen in collision or it may be a circular wound from the end of the handlebar impaling the abdomen.

Management:

An estimated 10% of bicycle injuries are related to contact with handlebars. Hemodynamically unstable patients should raise consideration for injury to the IVC or other abdominal vascular structures.

Your trauma survey places a lot of importance on the chest xray which can show diaphragmatic rupture or significant viscous perforation early on. Early laparotomy should occur in unstable patients, patients with significant peritonitis, or free air on x-ray.

Patients with isolated injuries to the abdomen, a negative FAST, normal labs (including LFTs/lipase/UA), and clinical improvement over 24 hours are safe for discharge.

Persistent LUQ pain that radiates to left shoulder during serial exams will generally require further investigation including advanced imaging like CT with IV contrast. If bilious vomiting ensues 24-48 hours after injury, consider a duodenal hematoma as hollow viscous injuries are rarely seen on CT scans.

Splenic injuries require serial hemoglobin/hematocrits, serial abdominal exams, and bed rest. Grades 1-4 are non-operative per American Pediatric Surgical Association. Splenectomy is rarely required though vaccination for encapsulated bacteria should be performed in the setting of severe injuries.

Read More: Gutierrez IM, Ben-Ishay O, Mooney DP. Pediatric thoracic and abdominal trauma. Minerva Chir 2013;68:263-274.

Puskarich MA, Marx JA: Abdominal Trauma, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 46:p 459-478,

Teisch LF, Allen CJ, Tashiro J, et al. Injury patterns and outcomes following pediatric bicycle accidents. Pediatr Surg Int 2015;31:1021-1025.


Headache and nausea after a night out on the town: Just a hangover? Or a "can't miss" diagnosis?

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It’s In-Service season, people! Let’s review the essentials of carbon monoxide poisoning. And before you start with your “Ugh, really? How many times do we have to—“, let me cut you off and have you gimme the full list of indications for hyperbaric oxygen therapy…. EXACTLY. Are you ready to review now?

1)  How do these patients present?

HISTORY, HISTORY, HISTORY. The classic example goes something like: A family of five presents from home in the dead of winter complaining of headaches associated with a myriad of vague, nonspecific complaints.

Later on, you overhear mom mention, out of frustration, that she had to pay for an Uber XL to get the whole fam to the ED tonight, since dad’s Camero was ‘on empty.’   Turns out, upon arriving home from the bars last night, dad accidentally left his car keys in the ignition before passing out in the doorway connecting the garage to the kitchen. (Ok, so maybe you won’t see that last part on the boards, but it’s my favorite real-life example).

The most common complaints: (1) HEADACHE, (2) nausea, (3) dizziness, and mental status changes with more severe toxicity (memory disturbances commonly manifested as amnesia, decreased cognition, stupor, coma, gait disturbances, etc). Keep in mind that the list of potential associated complaints is broad and encompass nearly every organ system.

Don’t count on the physical exam to nail the diagnosis. Remember that pulse oximetry is not affected. Know the traditional buzz words “cherry red” lips and skin for the boards; but also know that these are rarely seen in clinical practice.

2) How is it diagnosed?

Send a co-oximetry panel. Don’t get tripped up on details- you can send either a venous or arterial blood sample. If your clinical suspicion is high, do not delay treatment pending results.

A CO level >3% in non-smokers, or >10% in smokers, is diagnostic.

The actual percentages weakly correlate with associated symptoms and overall prognosis.  That being said, in the proper clinical setting, you can make the diagnosis and treat presumptively with normal or borderline CO levels.

3) How is it treated?

ABC’s- Intubate if the patient is altered and unable to protect his/her airway. Administer 100% oxygen via NRB. Keep this patient on a cardiac monitor. If for no other reason, CO binds to cardiac myoglobin with an even greater affinity than to hemoglobin, resulting in cardiac ischemia, ventricular arrhythmias, and cardiovascular collapse in severe cases. Finally, know your indications for Hyperbaric Oxygen (HBO).**

**note: this list is variable (and debatable) depending on the source, but generally accepted indications include: anyone who is pregnant, anyone who has signs of cardiac ischemia, history of prolonged LOC, or presence of neurological deficits.

  • Focal neurological deficits, coma, h/o transient LOC (transient LOC = independent risk factor for increased morbidity)
  • Pregnancy (with CO > 15%)
  • Evidence of cardiac ischemia, usually on EKG (or h/o CAD with CO >20%)
  • Basically any symptoms with CO >40%
  • Symptoms that don’t resolve after 6 hrs of 100% O2 via NRB

KEEP IN MIND: Clearance of CO via:

Room air: ~300 minutes

100% NRB: ~90 minutes

HBO: ~15-30 minutes

IDEALLY, TRANSFER FOR HBO SHOULD BE MADE ON A CASE-BY-CASE BASIS, AND SHOULD TAKE INTO CONSIDERATION THE STABILITY OF THE PATIENT FOR TRANSFER AND THE TIME INVOLVED FOR THE TRANSFER PROCESS ITSELF, AMONG OTHER THINGS.

The reason we transfer patients for HBO therapy = prevention of long-term neurologic sequelae.  

 

Want to learn more?

https://lifeinthefastlane.com/ccc/carbon-monoxide-poisoning/

https://lifeinthefastlane.com/ccc/hyperbaric-oxygen-and-carbon-monoxide-poisoning/

https://emedicine.medscape.com/article/819987-treatment#d12

https://emcrit.org/racc/cardiac-arrest-after-smoke-inhalation/

 

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Can you ID the active ingredient in the Cyanokit?

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1) Name the active ingredient in the Cyanokit. The Cyanokit contains hydroxocobalamin (HCN), which is essentially Vitamin B12 + an extra hydroxyl group. It is one of two main antidote kits in circulation for treatment of cyanide poisoning. The other most commonly distributed kit is aptly named the Cyanide Antidote Kit. It contains amyl nitrite and sodium thiosulfate.

2) Why does this matter?

One of these two kits is contraindicated in patients with cyanide poisoning in whom there is a concomitant concern for carbon monoxide poisoning (ie: patients involved in home/commercial fires or smoke inhalation victims-- the most common presentation for cyanide toxicity).

And why is this so? These two kits contain two completely different active compounds that work to clear cyanide by two completely different mechanisms.

Cyanokit: Cyanide displaces the extra hydroxyl group on B12 to form cyanocobalamin, which is excreted by the kidneys.

Cyanide Antidote Kit: sodium nitrite (or any other kit utilizing nitrites) reacts with hemoglobin to form methemoglobin (met-hgb). Cyanide, which throws a wrench in oxidative metabolism by binding with cytochrome oxidase via the electron transport chain, preferentially binds to Met-Hgb over cytochrome oxidase.

Stay with me, people, we’re almost done…. We know that Met-Hgb shifts the oxygen dissociation curve to the left, causing decreased oxygen delivery to the tissues. And increased tissue hypoxia via the production of Met-Hgb compounded by carbon monoxide -induced tissue hypoxia = BAD.

 

3) Quick! How is the Cyanokit administered?

Each kit contains a vial with 5 g of hydroxocobalamin in powdered form, IV tubing, transfer spike and instruction card. You will need to grab a bag of 0.9% normal saline.

Inject 200ml of NS into the vial. Rock (do not shake) the vial back and forth for 60 seconds to mix. Hang and infuse over 15 minutes.  The standard 5 g dose should be sufficient without needing to re-dose.

Don’t forget to draw labs BEFORE starting the infusion, since hydroxocobalamin will interfere with the results of labs that rely on the use of colorimetric probes, which includes your carboxyhemoglobin level, as well as lactate and certain LFTs.

 

Want to learn more?

https://lifeinthefastlane.com/tox-library/toxicant/inhalation/cyanide/

http://www.thepoisonreview.com/2009/12/18/hydroxocobalamin-vs-sodium-nitrite-cyanide-antidote-smackdown/

http://www.thepoisonreview.com/2010/04/10/cyanide-antidote-smackdown-hydroxocobalamin-vs-sodium-nitrite/

https://emcrit.org/racc/cardiac-arrest-after-smoke-inhalation/

 

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