Tag Archives: estes

Humeral Shaft Fracture

9 Jul

Important anatomy:

-insertion for pectoralis major, deltoid, coracobrachialis

-origin for brachialis, triceps, brachioradialis

-radial nerve courses along spiral groove

 

Important to evaluate for radial nerve palsy (wrist extension)

 

Non-operative treatment: cooptation splint

-arm flexed to 90 degrees

-splint just distal to the elbow up to the AC joint (sugar tong)

-no sling; instead use a “cuff and collar”, which supports the arm, while applying traction (see picture)

ELBOW DISLOCATION 1

Acceptable reduction:

  • <20 degrees of anterior angulation;
  • <30 degrees of varus/valgus angulation;
  • < 3 cm shortnening

 

Source: orthobullets.com, picture: rch.org.au; anatomy picture

 

Submitted by K Estes.

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Useful Tool: Necrotizing fasciitis score

6 Jul

the LRINEC = laboratory risk indicator for necrotizing fasciitis

 

-the score is based off of a retrospective observational study comparing laboratory results of patients with confirmed necrotizing fasciitis and those with severe cellulitis or abscess

 

-six criteria: CRP, WBC, hemoglobin, sodium, creatinine, glucose

 

-each of the criteria are weighted with a point value

 

-values totaling a LRINEC score >6 had a sensitivity of 90% and specificity of 95%; PPV 92% and NPV 95%

 

-useful tool? Sure. But also keep in mind this cut-off still missed 10% of patients with necrotizing fasciitis

 

-Summary: a LRINEC score > 6 could be used as a potential tool to rule in necrotizing fasciitis, but a score <6 should not be used to rule out the diagnosis

 

Sources:

Wong CH, Khin LW, Heng KS, Tan KC, Low CO. The LRINEC (laboratory risk indicator for necrotizing fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med. 2004 Jul; 32 (7):1535-41. PubMed PMID: 15241098.; MDCalc site; picture

 

Submitted by K Estes

 

 

Quick Hit: D-Dimer false positives

30 Jun

Thinking about ordering a D-Dimer for PE rule-out? What are the clinical conditions to consider thatmay make your D-Dimer falsely elevated?

  • Myocardial infarction
  • Stroke
  • Atrial fibrillation
  • Preeclampsia and eclampsia
  • Cardiovascular disease
  • Congestive heart failure
  • Severe infection
  • Surgery/trauma
  • Sickle cell disease
  • Severe liver disease (decreased clearance)
  • Malignancy
  • Renal disease
  • Pregnancy

 

Source: uptodate.com; picture

 

Submitted by K Estes.

Hypertrophic Cardiomyopathy (HCM)

25 Jun

QUICK HITS:

-only about 50% of patients will have positive family history

-average age of diagnosis is 30-40 years -> not always a teenager or young adult!

-clinical features: syncope, chest pain, palpitations, dyspnea

systolic murmur at apex or LLSB

  • increases with valsalva and standing
  • decreases with trendelenburg and squatting

-ECG abnormalities present >85% of the time

            high left ventricular voltage, left atrial enlargement

            tall R wave in V1 (mimics posterior MI)

            deep, narrow Q-waves in inferior, lateral leads

-definitive diagnosis Doppler ECHO

-treatment: beta blockers, calcium channel blockers; these patients should be urgently referred to cardiology and be counseled to avoid strenuous activity

Source: lifeinthefastlane.com, Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.; picture

Submitted by K Estes.

Anbesol for babies: why worry?

23 Jun

Dapsone and topical anesthetic agents (benzocaine, the active ingredient in anbesol) are the most common causes of acquired methemoglobinemia

Acquired methemoglobinemia is a result of certain ingested drugs leading to a state of oxidized (ferric state Fe+++) of hemoglobin, which are unable to bind oxygen. The remaining hemoglobin groups have an increased oxygen affinity causing a left shift.

The overall result is a functional anemia.

There are two ways for methemoglobin to be reduced back to hemoglobin:

  1. NADH-dependent catalyzed by cytochrome b5 reductase (b5R)
  2. NADPH generated by glucose-6 phosphate dehydrogenase (G6PD), but in order for this pathway to be activated, an extrinsically administered electron acceptor is required (methylene blue and riboflavin)

Infants are more susceptible to the development of methemoglobinemia because their erythrocyte cytochrome b5 reductase activity is 50-60% of adult activity

Treatment includes administration of intravenous methylene blue, 1 to 2 mg/kg, given over five minutes

Source: uptodate.com

Submitted by K Estes.

Myth Buster: Egg allergies and Propofol

18 Jun

 

Bottom line: there is no confirmed report of propofol-induced anaphylaxis in egg-allergic patients.

 

Propofol is made up of an oil water emulsion using soybean oil (10%) and egg lecithin (1.2%).

 

Lecithin (from the Greek lekithos, which means egg yolk) is a purified phosphatide found in egg yolk.

 

Egg allergy is most common during childhood and is usually outgrown by adulthood. The five major allergens that have been characterized originate from the egg white. Chicken serum albumin is the major allergen that has been described from the egg yolk.

 

The cases documented of anaphylaxis that have been associated with propofol were never followed with formal skin testing.

 

Now that we are on the topic… what about allergies to soy? Should you be worried that patients with soy allergies will have anaphylaxis to propofol?

 

Refined soy oil, such that is used to make propofol, is safe for people with soy allergy because the allergenic proteins are removed during the refining process.

 

Source: Anesthesia in the patient with multiple drug allergies: are all allergies the same? Current Opinion in Anaesthesiology. June 2011. Issue: Volume 24 (3), p 320-325; picture

 

Submitted by K Estes.

Baclofen pump toxicity and withdrawl

30 Mar

Baclofen is a gamma-aminobutyric acid (GABA) derivative, an inhibitory neurotransmitter that functions ultimately to relieve muscle spasticity.

Conditions in which you might see it used:  cerebral palsy, spinal cord injury, generalized dystonia, multiple sclerosis, intractable hiccups

How it’s given: oral or IV, topical creams, intrathecal via implantable device (baclofen pump)

Abrupt discontinuation of intrathecal baclofen has resulted in

  • high fever,
  • altered mental status,
  • itching,
  • exaggerated rebound spasticity,
  • muscle rigidity,
  • rhabdomyolysis,
  • multiple organ-system failure,
  • and death.

Typically, neurosurgery or a pain specialist (anesthesia) can be consulted to interrogate the pump. Treatment involves supportive care, administration of oral or enteral baclofen, and benzodiazepines.

Toxicity results in

  • muscular hypotonia,
  • areflexia,
  • somnolence,
  • respiratory depression,
  • bradycardia,
  • hypotension,
  • temperature instability,
  • coma. 

Measuring serum levels are not always reliable- the diagnosis is clinical.

Treatment involves supportive measures (IV fluids, vasopressors for hypotension, airwary support), discontinuation of the pump (as well as draining the reservoir to stop the motor), withdraw fluid/CSF from the catheter access port (to extract any baclofen that is still in the catheter or adjacent to it), and consideration of physostigmine (be aware of side effects of bradycardia and increased airway secretions).

 

Submitted by K Estes

 

References: Yeh RN1, Nypaver MM, Deegan TJ, Ayyangar R. Baclofen toxicity in an 8-year-old with an intrathecal baclofen pump. J Emerg Med. 2004 Feb;26(2):163-7. PMID: 14980337.

Uptodate.com