Tag Archives: Kongkatong

Spinal Fractures in AS vs. DISH

14 Jan

submitted by Matthew Kongkatong, M.D.


Ankylosing spondylitis:

-Chronic inflammation of the spine causes progressive ossification of the paraspinous ligaments

-Prevalence 0.1%-1.4%



AS: “bamboo spine”, ossification of disc spaces


Diffuse Idiopathic Skeletal Hyperostosis (DISH):

-Non-inflammatory process of known etiology causes progressive ossification of paraspinous ligaments.

-Prevalence varies 2.9%-25%

-Associated with obesity, advanced age, and diabetes mellitus


DISH: “flowing candle wax”, preserved disc spaces


Spine fractures in DISH and AS

-Review article of 93 papers including 345 AS patients and 66 DISH patients

65% of AS and 69% of DISH patients sustained fractures via low energy mechanisms life falling from sitting or standing

Most (80% in AS and 60% in DISH) fractures were in the cervical spine and most were hyperextension type injuries.

-67% of AS and 40% of DISH patients had a neurologic deficit on presentation and 13% of AS and 15% of DISH patients had neurologic deterioration ❤ months from presentation (compared to 0.08% in other population studies).

Most spine fractures are considered unstable because they extend into calcified ligaments and surrounding soft tissue, including into the intervertebral discs.

Calcified ligaments can transmit force and cause fractures in areas remote from the area of trauma.

References: Westerveld LA, Verlaan JJ, Oner FC: Spinal fractures in patients with ankylosing spinal disorders: a systematic review of the literature on treatment, neurological status and complications. Eur Spine J 2009, 18:145-156.; http://www.orthobullets.com/spine/2045/dish-diffuse-idiopathic-skeletal-hyperostosis


Dextromethorphan intoxication

8 Sep

Dextromethorphan (DXM):


Hepatic P450 enzymes into active metabolite dextrorphan.  10% of patients are poor metabolizers.

Time of peak serum concentration is 2-2.5 hours

Half-life for DXM is 1.5-4 hrs.  Half-life for dextrorphan is 3-6 hrs

Receptor activity

  • DXM is an opioid agonist at the brain stem cough center. Can cause respiratory depression, particularly in children
  • Dextrorphan
    1. serotonergic agonist: can cause serotonin syndrome
    2. adrenergic reuptake inhibitor: tachycardia, mydriasis, HTN, diaphoresis
    3. NMDA and glutamate antagonist: behavioral effects ranging from euphoria to complete dissociation. Gait ataxia.


Clinical effects are at plateaus of DXM doses.

  • Mild stimulation at 1.5 mg/kg or 100-200 mg
  • Euphoria and hallucination at 2.5-7.5 mg/kg or 200-400 mg
  • Partial dissociation at 7.5 mg-15 mg/kg or 300-600 mg
  • Complete dissociation at 15 mg/kg or >600 mg


Formulations are often combination medications with:  

  • diphenhydramine,
  • acetaminophen,
  • salicylates,
  • phenylephrine,
  • and pseudoephedrine.


Workup should include labs looking for coingestants like acetaminophen and salicylates. DXM levels are available only at dedicated toxicology laboratories and not helpful.

Treatment of respiratory depression is naloxone IV 0.1mg/kg.  Other than that, treatment is supportive and specific to coingestants.


Submitted by Matthew Kongkatong MD.



Dextromethorphan. DrugPoints summary. Micromedex 2.0. Truven Health Analytics, Inc. Greenwood Village, CO. Available at: http://www.micromedexsolutions.com. Accessed September 4, 2014.

Rosenbaum Chris and Edward Boyer. Dextromethorphan abuse and poisoning: clinical features and diagnosis. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA.

Rosenbaum Chris and Edward Boyer. Dextromethorphan poisoning: treatment. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA.