Continued from Part 2

My apologies for the delay on this update: there have been major computer troubles here at EMSB HQ. We’re back in action now with the final piece of our scenario.

Ultimately, this patient was rapidly packaged and transported emergently to the nearer facility for immediate imaging to rule out intracranial hemorrhage. Her final diagnosis and disposition are not known.

This case demonstrates the ambiguity we’re often faced with in the field, where we may encounter findings in our assessment that are suggestive of Badness, but not definitively so. Particularly when faced with a patient whose complaints are minor or who generally presents well, it can be difficult to make the call to upgrade these patients to a higher level of care. Nobody wants to be the Boy Who Cried Wolf. However, our job is to get people to the most appropriate care, and although we should try to minimize overtriage, within reason, safe is better than sorry. The situation can be particularly difficult when we are dispatched as a low priority to an unremarkable complaint; changing gears from a low- to a high-severity mode takes more balls than merely continuing what’s already been set in motion.

 

Assessment: The Pink Flags

The suggestive if not outright alarming findings (I like to call them “pink flags” — not quite red, but close) with Ms. Smith were the following:

• A recent fall, reportedly with a blow to the head and loss of consciousness.
• A subsequent (apparently new) complaint of dysnomia (the inability to express oneself in words, a form of aphasia), which suggests some sort of neurological or metabolic insult.
• A subsequent and sudden onset of vomiting with no other apparent explanation. This could be a sign of hemorrhagic stroke, although more minor head injuries can also induce vomiting.
• A history of Coumadin (warfarin) use — a “blood thinner” or anticoagulant — which is a risk factor for intracranial bleeding.
• A complaint of “head pressure,” which remotely suggests headache, typical in head bleeds.
• A reported positive finding on a neurological test (failed finger-to-nose), which potentially supports a neurological event.
• A complaint of dizziness, which is suggestive of either a balance-type (inner ear) pathology or a neurological one.
• A finding of hypertension, which may or may not be elevated above the patient’s baseline.

On the other hand, the following findings point generally away from the likelihood of a stroke or intracranial bleed:

• An alert and oriented patient mentating at her cognitive baseline.
• A normal Cincinatti Stroke Scale, which assesses for arm drift, facial droop, and speech slurring.
• A lack of other “focal” neurological deficits (an abnormality that is localized to a single sensory or motor region, such as a droop in one half of the face, or loss of sensation in the left arm but not the right). She has equal peripheral CSM, no complaints of partial vision loss, and so forth.
• A lack of any significant headache. Although there is a vague complaint of pressure, which could be explained by the actual trauma to the head, headache associated with intracranial hemorrhage is typically severe and sudden.
• Equal and non-dilated pupils. (Although they do present as small, this is an unremarkable finding in the elderly, as is poor reactivity — constricted pupils can’t constrict much more.) Furthermore, the eyes track well towards all sectors; gaze paralysis is suggestive of brain damage. None of this is highly predictive, however.
• A lack of rigidity of the neck, which would support a hemorrhage.

Taken together, this cloud of positive and negative findings produces our clinical picture. We are not so fortunate that any one finding is diagnostic, or highly suggestive to either rule in or rule out Badness. Rather, we have a constellation of weak findings.

 

Differential: Strokes and Bleeds

It can be important to make a distinction between intracranial hemorrhage and stroke. Intracranial hemorrhage (we’ll call it ICH, not to be confused with “intracerebral hemorrhage,” discussed below — both abbreviations are seen in the literature) describes bleeding anywhere inside the dome of the skull, typically from a ruptured vein or artery. Sometimes, this occurs inside the skull but outside the brain, between the various membranes that lay between brain and skull: epidural (outside the dura), subdural (inside the dura), and subarachnoid (inside the arachnoid) are the main types and locations.

Bleeding deep within the tissue of the brain itself is also possible, and is a subcategory of ICH called intracerebral hemorrhage.

A stroke is a localized injury to brain tissue resulting in permanent neurological deficits. By far, the most common cause is known confusingly as ischemic stroke, and describes an event where a clot or other obstruction blocks an artery that feeds a portion of the brain. (This is the same mechanism that damages the heart in a myocardial infarction.) The other main cause of stroke is hemorrhagic, when an artery bleeds openly into the brain, causing damage both from the loss of perfusion to downstream tissue, as well as from the pressure caused by the growing pocket of blood. This is where stroke and head bleeds intersect: when either an intracerebral or subarachnoid hemorrhage is sufficient to cause local neurological damage and permanent loss of functional brain tissue, a stroke results. Epidural and subdural bleeds do not cause stroke per se, although they can still result in acute neurological symptoms due to the increase in intracranial pressure.

Although the effects of stroke are similar with either ischemic or hemorrhagic etiologies, hemorrhagic strokes may additionally produce the telltale signs of rising intracranial pressure, such as headache, vomiting, general (non-focal) neurological deficits, and in the late stages, Cushing’s triad (bradycardia, irregular respirations, and hypertension).

 

Applying the Differential

Ms. Smith’s history is certainly suggestive for a bleed. Head trauma is the most common cause of ICH, and with her Coumadin use, she should probably be worked up regardless of her minimal complaints. Her additional neurological complaints make this a potential “uh oh,” advising transport to a facility that can provide immediate care. However, there are some notable negatives that tamper this enthusiasm.

For one thing, it would be unusual for a bleed of this type to present so inconspicuously. If severe, we would expect to see a profoundly altered mental status, up to and including outright coma, and probably a significant headache. If there is also the localized infarct of a stroke, we would expect focal neurological complaints — local damage should cause focal deficits. The reason that the Cincinatti Stroke Scale uses facial droop and arm drift to screen for stroke is because the majority of strokes will be revealed by unilateral deficits. Ms. Smith has none of this.

If there is indeed a stroke, the type most consistent with her presentation is probably a cerebellar stroke affecting the vestibular (balance) system. This region is responsible for coordinating motor and sensory signals, allowing synchronized behavior, such as the finger-to-nose test she failed. It’s also responsible for proprioception and balance; hence, damage could produce her complaint of dizziness. It is always important to distinguish “dizziness” (a sensation of spinning, consistent with either vestibular stroke or BPPV) with “lightheadedness” (a dimming of the vision, as seen in orthostatic hypotension). This is a notable possibility mainly because cerebellar injuries often do not produce the focal deficits characteristic of other strokes.

If you are very enterprising, Dr. Scott Weingart describes a three-test screen (introduced by Dr. David Newman-Toker and Dr. Jorge Kattah here) which can help catch vestibular stroke in borderline cases such as these. It uses two simple and easy tests, plus a third — involving a head twist — which is more difficult to assess and vaguely terrifying to perform. If you plan to use any of them, it’s the sort of thing you should be practicing beforehand. (I personally find the head twist finicky and liability-prone in most circumstances.) Like all such tests, their role in the field should only be to help determine transport destination and priority, and give you additional information on how hard to push a reluctant patient towards transport. It is not appropriate for enterprising Dr. Medics to use as ammunition to say, “oh, it’s negative, you’re clearly fine.” The weight of a thousand lawyers will descend upon you, and rightly so, the day you decide that you have the power to rule out major sickness from your ambulance.

If an extra-cerebral hemorrhage proved to be the culprit, a subdural bleed is probably the most plausible, due to the relatively slow and insidious development of the symptoms.

Additional tests that were not performed, but might have been useful, include a visual field test (testing at minimum eyesight in both visual hemispheres), a “stick out your tongue” test (looking for deviation to either side), and a more complete test of reasoning and recall (portions of the Folstein Mini-Mental, for instance).

Many of the major components of the peripheral neurological exam we performed are taken from this excellent lecture by Dr. Gene Hern of AMR Contra Costa County (see 37:20 through 40:50), and is my favorite expansion on the typical “squeeze my hands.” Sharp sensation can be tested with the tip of a pen — or you can use Dr. Hern’s pinching method.

Two other tips: when performing the facial droop test, “show me your teeth” produces better results than “smile” — patients tend to give a larger, more symmetrical smile using more muscles. And when testing for arm drift, remember that the patient’s eyes should be shut, and the hands should be facing upward (supinated); this is a more difficult test and therefore more sensitive.

 

Treatment and Transport

The key points on our differential therefore come down to two: intracranial hemorrhage vs. anything else. “Anything else” could be any number of things that produce diffuse and global symptoms, including metabolic problems or even a brain tumor. Diabetic etiologies are always be a possibility, although glucometry was fortunately available to rule that out. In general, the old standby AEIOUTIPS is the sort of thing we’re looking at here. And remember, multiple concomitant pathologies are just as likely as one all-encompassing Badness, if not more so. As a starting point, we should bear in mind that around two-thirds of falls with loss of consciousness in the elderly will end in death. The risk is high.

As always, the differential only matters to the extent that it will affect our decisions. What will our field treatment be?

Certainly oxygen. Although hypoxia is unlikely to be significantly contributing to Ms. Smith’s complaints, it could be playing a role. Depending on local protocol, low-flow through a nasal cannula may be plenty.

In the case of stroke, there is some evidence that hyperoxygenation with high-flow O2 can contribute to worse outcomes. The 2010 Emergency Cardiovascular Care guidelines from the American Heart Association recommends titrating oxygen therapy to maintain an oxygen saturation of at least 94%, but not necessarily slapping on a non-rebreather at 15LPM. Depending on whether oximetry is available to you, and depending on your local policies and attitudes, this may or may not fly; it’s something to ask your boss and medical director.

What about C-spine immobilization? As always, this will be a matter of opinion and protocol. In some areas, any fall from standing height, with a blow to the head — especially for an elderly patient — must always be immobilized. However, clinically I would not consider it indicated here. Whatever criteria or standards you adhere to for selective immobilization, Ms. Smith likely meets them: she has had no peripheral neurological deficits (weakness, tingling, numbness, pain), no neck or back pain or tenderness, no factors that would impair her reporting of the above (such as distracting injuries or altered mental status), turns her head freely, and although not ambulatory on our arrival was obviously ambulatory for several hours prior. Remember that the only reason for the immobilization of blunt head trauma patients is the suspicion that any injury substantial enough to cause ICH may also be substantial enough to cause a cervical spine fracture — and while a valid reason for suspicion, this is just one factor to consider. (Conversely, if we had found focal neurological deficits, we would have likely been unable to determine whether it was secondary to the suspected ICH, or secondary to a spinal injury — immobilization would have been unavoidable.)

Close monitoring will be warranted, especially if we do suspect a bleed. Although Ms. Smith appears currently stable, there is a real possibility of her mental status deteriorating; epidural bleeds in particular are famous for a “lucid interval” following the initial trauma, after which the patient suddenly and catastrophically decompensates. Control of the airway and ventilatory support should be provided as necessary. If there are signs of herniation syndrome — an acute rise in intracranial pressure, resulting in “coning,” or the brain being forced through the openings in the skull — it may be reasonable to hyperventilate the patient slightly, at a rate of 1 breath every 3 seconds. Although the drop in systemic CO2 caused by a higher ventilatory rate results in a systemic respiratory alkalosis (high PH), which tends to reduce inflammation and hence lower intracranial pressure, it also reduces cerebral perfusion; it is therefore no longer recommended as a routine practice. Intracranial pressure is a challenging problem that produces a physiological tightrope that we need to delicately walk; hyperventilation is a last-ditch flailing that’s only advisable when things can’t get much worse.

Is an ALS intercept appropriate? Again, this may depend on your protocols. As Ms. Smith currently presents, there is no benefit to ALS care; whether or not she’s hemorrhaging, that’s a matter for the hospital, not the field. However, if should deteriorate, then ALS could prove very valuable in the management of her airway, seizures, cardiac arrhythmias, and other complications. With Ms. Smith’s currently excellent clinical picture, and the short transport to definitive care, I would not attempt to meet the paramedics unless I tripped over them in the driveway. However, the opposing argument can easily be made, and I wouldn’t call it wrong.

The most appropriate destination for this patient will likely be the nearest primary stroke center. A “primary” stroke center is required to have various resources available 24/7, the most important in our case being a CT scanner. The definitive determination of the presence or absence of our possible bleed will be via some form of CT, or possibly by MRI (if available).

Treatment may or may not involve surgical intervention, depending on location and severity. Many of these cases are managed conservatively, both because the benefits of surgery are often small and the harm (especially in deep brain bleeds) often large. As a result, my personal inclination is to steer towards the nearest facility that can provide immediate imaging; if surgical intervention beyond their capabilities is found to be indicated, transfer can be arranged. I would not advise transporting to the more distant requested facility; the only notable benefit other than the patient’s convenience and comfort (which we won’t diminish) is that her medical records and following physicians may be available there, and her history doesn’t seem complex enough for this to matter significantly.

In some areas, a few hospitals are designated as “comprehensive” stroke centers, a step above primary. These facilities are specialty centers with the most advanced stroke management capabilities, which may include diagnostic and interventional methods that would be appropriate to us. The system of comprehensive centers is still inchoate and only available in some states; check if yours is one of them.

Your local hospitals may follow a prehospital protocol that allows for a “stroke activation,” similar in principle to trauma or cath lab activations, where appropriate resources are mobilized by request of EMS and waiting upon your arrival. Depending on the local indications (for instance, your hospitals may demand a positive Cincinatti Stroke Scale), Ms. Smith might qualify.

 

Conclusion

In the end, I was unable to obtain patient follow-up on Ms. Smith. She received low-flow O2, was not C-spine immobilized, and was diverted to the nearer stroke center with an emergent transport and no ALS. An entry notification was made with an advisory of her status, although no formal stroke alert was given. She was stable throughout.

It’s important to note that our assessment of Ms. Smith, our analysis of her differential, and our resulting treatment and transport decisions, are not actually dependent on her eventual diagnosis. It doesn’t matter whether we ended up being “right” — hence, it doesn’t matter that we never found out the “answer,” even though I do love a good puzzle and I admit that I wanted to know. As long as we made an appropriate interpretation of our assessment findings, and made appropriate decisions based on them, then we got it right. Perhaps her complaints turned out to result from an alien egg incubating in her chest; that wouldn’t make us wrong, it would only mean that she was an aberration. Our business in the field is to play the odds in a responsible way, weighing risk-vs-benefit to provide our patient with the best chance of a good outcome.

That’s all. And that’s plenty.