Lateral Canthotomy For Orbital Compartment Syndrome
I’ve previously written about the orbital compartment syndrome and described the symptoms in the awake patient. I’d like to share a video of the procedure and provide a tip for diagnosing it in unconscious patients.
Patients at risk will have obvious facial trauma. During your physical exam, look for proptosis. This is caused by swelling or hemorrhage behind the globe pushing it forward. It may manifest itself as uneven opening of the eyelids, with the affected side being “propped" open (get it?). But in trauma, there may be significant edema which keeps the lid closed.
The easiest way to observe proptosis is to stand above the patients head, looking toward their feet. Crouch down so you can look across the lids in a direction horizontal to the floor. You should easily be able to detect if one eye protrudes further that the other.
You can also do a poor man’s compartment pressure test by gently using your thumbs to compress both globes simultaneously. If there is substantial difference in resistance between the two sides, a compartment syndrome may be present. Important note! Do a thorough globe exam first! If there is any evidence of globe rupture (hyphema, irregular pupil, extra tissue in the anterior compartment), don’t press the eye or perform a canthotomy. CT scan of the facial bones can help confirm the diagnosis if a mass effect is seen in the orbit or if the optic nerve appears to be on stretch.
The orbital compartment syndrome is an emergency! Once diagnosed, immediately proceed to canthotomy. Otherwise, damage to the optic nerve and retina is likely, and the patient may become blind in the affected eye.
Can You Reverse Clopidogrel (Plavix) With Platelets?
More and more of our patients are being placed on drugs that interfere with clotting in one way or another. I’ve written a number of articles on the trauma implications of warfarin and some of the newer anticoagulants, and provided some sample algorithms for reversal.
But what about antiplatelet agents? These are commonly used in patients with vascular disease, but can create problems when injury causes bleeding in dangerous areas like the inside of the skull. Can’t you just give a few bags of platelets and stop worrying?
A French group performed a prospective, observational study that monitored the response to platelet infusion in patients taking aspirin or clopidogrel. Patients requiring emergency surgery who were taking one or both of these agents and who were also confirmed as responding to therapy by the Verify Now device (Accumetrics, San Diego, CA) were enrolled.
Here are the factoids:
25 patients were enrolled during the 3 year study period
13 were taking aspirin, 8 clopidogrel, and 4 were taking both
Patients received an average platelet infusion of 0.1U/kg
Platelet function normalized in all but one of the aspirin patients
Platelet function improved but did not normalize in any of the clopidogrel patients
Bottom line: Surprised? The existing literature supports platelet infusion for aspirin, and suggests that it can correct platelet dysfunction after a loading dose of clopidogrel. But what about established therapy? This study shows that it improves function, but not necessarily enough to be safe.
Why? Most likely, the long-acting active metabolites of this drug are still circulating in the plasma and poison the new platelets as soon as they are given. Additional strategies (and more platelets?) will be needed to reverse the effect of clopidogrel in injured patients who are on established therapy.
Patients who have sustained a traumatic pneumothorax occasionally ask how soon they can fly in an airplane after they are discharged. What’s the right answer?
The basic problem has to do with 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 a volume of gas becomes. Most of us hang out pretty close to sea level, so this is not an issue.
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. If they are young and fit, they may never know anything is happening. But if they are elderly and/or have a limited pulmonary reserve, it may compromise enough lung function to make them symptomatic.
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 that has a single Level 2 recommendation that commercial air travel is safe 2 weeks after resolution of the pneumothorax, and that a chest xray should be obtained immediately prior to travel to confirm resolution.
Bottom line: 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.
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.
Every trauma professional knows that seat belts save lives. Numerous studies have borne out the survival benefits of wearing them. But do those same professionals practice what they preach?
A study by NHTSA study showed that at least 42% of police officers killed in car crashes were not wearing their seat belts. The number of officers killed in traffic accidents in 2010 has increased by 43% over 2009 numbers. Possible reasons may be that seat belts impede the process of getting into and out of the car quickly, and that the belt may get tangled in utility and gun belts.
What about paramedics and EMTs? I couldn’t find any studies looking at this group. However, observation tells me that medics in the patient care compartment don’t always buckle up. The reason typically given is that wearing a belt may compromise patient care by limiting access to equipment, using the radio, or performing CPR. However, I think that patient care is even more limited if the EMS professional is disabled or killed in a rig crash. The patient is much more likely to survive such a crash since they are firmly strapped into place.
How can you stay safe in the back?
Make a commitment to your colleagues (and family) to always belt in
If appropriate, try to do as much of your assessment and interventions as possible before moving
Organize your work area so that commonly used and critical equipment is within easy reach
Use a cell phone for communication if the radio mic is too far away
If you absolutely do need to unbelt, try to do so only when the rig is stopped at a light or stop sign.
I’m interested in your comments about how common of a problem this really is. Unfortunately, I don’t think NHTSA will be doing any studies on this one.
The Trauma Professional's Blog provides information on injury-related topics to trauma professionals. It is written by Michael McGonigal MD, the Director of Trauma Services at Regions Hospital in St. Paul, MN. Regions is a Level I Adult Trauma Center, and has partnered with Gillette Children's Specialty Hospital to become the first Level I Pediatric Trauma Center in the Upper Midwest.