Category Archives: General

Management of CSF Otorrhea/Rhinorrhea

The management of CSF leaks after trauma remains somewhat controversial. The literature is sparse, and generally consists of observational studies. However, some general guidelines are supported by large numbers of retrospectively reviewed patients.

  • Ensure that the patient actually has a CSF leak. In most patients, this is obvious because they have clear fluid leaking from ear or nose that was not present preinjury. Here are the options when the diagnosis is less obvious (i.e. serosanguinous drainage):
    • High resolution images of the temporal bones and skull base. If an obvious breach is noted, especially if fluid is seen in the adjacent sinuses, then a CSF leak is extremely likely.
    • Glucose testing. CSF glucose is low compared to serum glucose. 
    • Beta 2 transferrin assay. This marker is very specific to CSF. However, the test is expensive and results may take several days to a few weeks to receive. Most leaks will have closed before the results are available, making this a poor test.
  • Place the patient at bed rest with the head elevated. The basic concept is to decrease intracranial pressure, which in turn should decrease the rate of leakage. This same technique is used for management of mild ICP increases after head injury.
  • Consider prophylactic antibiotics carefully. The clinician must balance the likelihood of meningitis with the possibility of selecting resistant bacteria. If the likelihood of contamination is low and the patient is immunocompetent, antibiotics may not be needed.
  • Ear drops are probably not necessary. They may confuse the picture when gauging resolution of the CSF leak.
  • Wait. Most tramatic leaks will close spontaneously within 7-10 days. If it does not, a neurosurgeon or ENT surgeon should be consulted to consider surgical closure.

References:

  1. Brodie HA, Thompson TC. Management of complications from 820 temporal bone fractures. Am J Otol, 1997;18:188-197.
  2. Brodie HA. Prophylactic antibiotics for posttraumatic cerebrospinal fluid fistulas. Arch Otolaryngol Head, Neck Surg. 123:749-752.
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In my last post, I discussed the Passy-Muir valve, which allows patients who have a tracheostomy tube in place, and are not on a ventilator, to talk. But what about patients who are still vent dependent? It’s very frustrating for both patient and trauma professionals when we can’t communicate with each other.

Pulmodyne, Inc. makes the Blom tracheostomy tube system, which solves this problem. This device has a large fenestration in the back of the tube with a special bubble valve (see below), coupled with an inner cannula that has a 1-way flap valve. This allows controlled release of air into the pharynx, enabling speech while on the ventilator.

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A multicenter study looked at voice production and intelligibility of speech in a group of 23 ventilated patients with a trach tube in place. Although not entirely clear in the paper, it appears that all were changed to Blom trach tubes for the study (2 had one in place at the beginning of the study). Overall, voice production and intelligibility were good. Most were able to begin audible speech within about 6 minutes of initial application. One deconditioned patient took longer. The video below shows an example of the speech that is achievable.

Bottom line: This novel product allows a subset of trauma patients to speak while still on the ventilator. It is most appropriate for those who do not have significant head injury, especially those with facial trauma requiring airway protection with a tracheostomy.

Related post:

I have no financial interest in Pulmodyne, Inc.

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What Is: A Passy-Muir Valve?

Some critically injured patients undergo tracheostomy due to prolonged ventilatory failure. As they recover, the trach tube is usually downsized over time until it can be permanently removed. Unfortunately, this process may take a month or more, and the patient is generally unable to speak during this time. Writing and other forms of communication are both slow and frustrating, so a Passy-Muir valve may be attached to the trach to allow (nearly) normal speech during the recovery process.

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The Passy-Muir is a one way valve that allows air to be inhaled through the trach tube, but not exhaled through it. Instead, the air must circulate around the tube and up through the trachea to the pharynx. This particular brand has features that help keep the tube from collecting secretions during speech. See the brief video from the manufacturer below.

The downside to this device is that it increases the work of breathing during exhalation because air must flow around the entire trach tube, which is narrowing the available tracheal lumen. Note: if the trach tube has a balloon, it must be deflated or the patient will not be able to breathe! Some patients do not have enough strength to overcome this narrowing initially, and may not be able to speak or say more than a few words at a time. This improves with practice, and helps speed up tube removal.

Use of a fenestrated tracheostomy tube with the Passy-Muir is helpful, because it has a strategically placed (but small) hole that allows air flow through a portion of the tube. When this type of tube is used, the balloon must also be deflated, since it is subject to mucus plugging which would completely obstruct the airway. Work of breathing is still increased because this hole is small relative to the diameter of the trachea.

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Note: I have no financial interest in Passy-Muir Inc or any other tracheostomy product manufacturers.

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Flying After Pneumothorax

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.

Related post:

References:

  • 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.
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Why People Don’t Change Their Minds Despite The Data

Has this happened to you?

Your (emergency physician / neurosurgeon / orthopaedic surgeon) colleague wants to (get rib detail xrays / administer steroids / wait a few days before doing a femur ORIF). You question it based on your interpretation of the literature. You even provide a stack of papers to them to prove your point. Do they buy it? Even in the presence of randomized, double-blinded, placebo-controlled studies with thousands of patients (good luck finding those)?

The answer is generally NO! Why not? It’s science. It’s objective data. WTF?

Sociologists and psychologists have shown that there is a concept that they call the Backfire Effect. Essentially, once you come to believe something, you do your best to protect it from harm. You become more skeptical of facts that refute your beliefs, and less skeptical of the items that support them. Having one’s beliefs challenged, even with objective and authoritative data, causes us to hold them even more deeply. There are plenty of examples of this in everyday life. The absence of weapons of mass destruction in Iraq. The number of shooters in the JFK assassination. President Obama’s citizenship.

Bottom line: It’s human nature to try to pick apart a scientific article that challenges your biases, looking for every possible fault. It’s the Backfire Effect. Be aware of this built in flaw (protective mechanism?) in our psyche. And always ask yourself, “what if?” Look at the issue through the eyes of someone not familiar with the concepts. If someone challenges your beliefs, welcome it! Be skeptical of both them AND yourself. You might just learn something new!

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