“Should You Find Yourself in Afghanistan.” A helpful tip from our Chief resident in this week’s Case Conference Summary

Conference moderator and forever resident Dr. Zach Adams leads off this week’s case conference with a 65-year-old female diabetic presenting with the always challenging chief complaint of a “room-spinning” dizziness, otherwise classified as vertigo. She describes it as worse with position, severe, and present intermittently for the past few days. Suspicious for peripheral vertigo, Dr. Adams performs the Dix-Hallpike maneuver (Figure 1). Seconds after placing the patient in the reclined position with head turned laterally, the patient displays strong rotary nystagmus and promptly vomits on Dr. Adams’ shoes. Confirming his suspicion for benign paroxysmal peripheral vertigo, Dr. Adams then successfully performs the Epley maneuver (Figure 2) to reposition the otoliths within the semicircular canal and relieve the patient’s vertigo.

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Figure 1: Dix-Hallpike Maneuver

 

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Figure 2: Epley Maneuver

 

However, what if this vertigo had not given a positive on the Dix-Hallpike test? Central vertigo needs to be ruled out.

 

This is done using the HINTS exam, or Head Impulse, Nystagmus, Test of Skew to diagnose, a beside examination that has been shown to be superior to early MRI in the detection of posterior strokes (Kattah et al., 2015).

 

Components

Head Impulse: Corrective saccade implies peripheral vertigo. Lack of corrective saccade means the vestibule-ocular reflex is intact, as you would find in central vertigo (or a person not actually suffering from vertigo at all, like you or me).

Nystagmus: unidirectional, horizontal nystagmus is suggestive of peripheral vertigo. If the nystagmus is bidirectional, torsional, or vertical, this is suggestive of a central cause

Test of Skew: Positive test is suggestive of central pathology

View the following video for instruction on how to correctly perform this maneuver!

https://www.youtube.com/watch?v=1q-VTKPweuk

Excellent article detailing the sensitivity of this test listed below. As Dr. Aziz pointed out, these tests were conducted by neuro-ophthalmologists, so be sure that you understand the tests themselves in order to be able to expect any sensitivity.

Kattah, J. C., Talkad, A. V., Wang, D. Z., Hsieh, Y.-H., & Newman-Toker, D. E. (October 26, 2009). HINTS to Diagnose Stroke in the Acute Vestibular Syndrome. Stroke, 40, 11, 3504-3510.

 

Dr. Yeh then shares the case of a schizophrenic gentleman, previously admitted the psych hospital, presenting back from psychiatry to the ED with the somewhat ironic chief complaint of altered mental status. Per report, he has had increasing fatigue and lethargy. His physical exam is significant for slow, one-word responses, slow gait without any focal neurologic deficits. A quick medication review revealed the recent addition of 1500mg of Depakote. His blood valproic acid level was found to be 130 mg/L, only slightly elevated, but given its recent addition to his medication list and coupled with the clinical scenario, the likely culprit in his altered mental status.

How to treat?

Discontinue the offending medication immediately. In order to treat hyperammonemia, lactulose should be given. How much you ask? “It should be given until the patient poops,” as Dr. Martinez reminds us. Additionally, in the case of severe toxicity where the patient is at risk for coma and death, dialysis should be considered. Dr. Rublee advises that this is most likely to be beneficial in the setting of high serum Depakote levels, as you can expect a high percentage of drug not already bound to serum protein.

 

Next up, is Dr. Schwab with a case of a friendly wrestling match gone wrong. Our patient comes in after feeling a “pop” sensation in his left arm while wrestling his roommate. His XR can be seen below:

postdisloc

Diagnosis? Posterior dislocation of the elbow without fracture. This needs to be reduced. But first, Dr. Schwab took a moment to discuss his sedation, which he accomplished with propofol.

 

He offers the following advice:

  • Ensure sedation is adequate. Do not be afraid to pause the reduction to do so.
  • When using propofol, start with a 1mg/kg bolus followed by 20mg ever 30s until desired sedation is achieved
  • Consider pre-medicating with fentanyl to decrease amount of propofol needed (though be wary of increased potential for adverse events from a respiratory standpoint)
  • Consider ketamine as adjunct – independent subdissociative doses vs ketofol

 

Once adequate sedation was ensured, reduction was accomplished using traction-counter-traction while applying firm pressure over the olecranon.

reduction

Video of proper reduction technique can be found here.

 

Dr. Rublee is up next with her case of a 29-year-old inmate whose face was on the receiving end of a flaming bowl of lit baby oil and chili powder. He presents in agonizing eye pain with concern for chemical and thermal damage to his eyes. Dr. Rublee quickly tested eye pH, finding it elevated (7-8 normal). Realizing the need for irrigation, she obtained a Morgan lens and began irrigation, choosing then to discuss its proper usage, as seen below.

  • Anesthetize with tetracaine, with care to ensure that pH has already been tested, as tetracaine may alter the pH.
  • Connect the Morgan lens to irrigation (LR preferred but normal saline works) and insert in a fashion similar to that of a contact lens
  • First irrigate under the upper eye lid for 30 minutes and then move to under the lower lid for an additional 30 minutes

 

When in doubt, the official instructions can be found on the manufacturer’s website:

 

morganlens

Dr. Carrol took this opportunity to remind us that this may not be a suitable option in young children as their eyes may be too small, in which case manual irrigation is the preferred option. Dr. Adams, before closing out the day, advises a quick and useful alternative to the Morgan lens, “should you find yourself in Afghanistan.” He recommends as a substitute placing the prongs of a nasal cannula on either side of the bridge of the nose. The NC can then be hooked up to a saline bag, providing continuous irrigation to both eyes.

This wraps up another week of AMP at The Ohio State University. Thanks for reading and check back next week!

 

 

 

 

 

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