Archive | January, 2012

Cocaine: quick review

31 Jan

PATHOPHYSIOLOGY:

  • Release of NE, blocks NE reuptake
  • Release & reuptake blockade of serotonin and dopamine
  • Na channel blockade – local anesthetic effect
  • Fat soluble – crosses blood brain barrier
  • Stimulates CNS, especially limbic system, which potentiates dopaminergic transmission – pleasurable behavioral effects
  • REMINDER: don’t treat with a beta-blocker (shunts to unopposed alpha receptors)


NOTABLE NUMBERS:

Route
Onset
Peak(min)
Duration(min)
 Half-life (min)
Inhalation
7s
1-5
20
40-60
IV
15s
3-5
20-30
40-60
Nasal
3min
15
45-90
60-90
Oral
10min
60
60
60-90

DEATH BY…

  • Tachydysrhythmias cause most non-traumatic deaths
  • Stroke
  • SAH
  • Hyperthermia
  • MI (acute vasospasm, dysrhythmia, chronic accelerate atherogenic disease)

HEART BREAKER:

  • Patients with cocaine-related MI often have fixed atherosclerotic lesions.
  • Cocaine can induce increased heart rate and BP, resulting in increased myocardial oxygen demand.
  • effects of cocaine also include myocarditis and dilated cardiomyopathy.

10-SECOND RECAP:
stims norepi, serotonin, dopa release, blocks reuptake; also Na+ channel blocker
DON’T treat with beta-blocker (unopposed alpha-receptor action)
–inhaled/IV works in seconds, nasal/oral works in minutes, lasts hour(s)
sympathomimetic response, and resulting problems (dysrhythmias, MI, stroke, SAH, hypertherm, etc.)
–say NO to drugs.

Submitted by J. Gullo. 

Intussusception: quick review

30 Jan
(scroll to bottom for 10-second version)
DEMOGRAPHICS
–most common cause of intestinal obstruction in kids 3 months-6 years of age.
male:female ratio is 4:1
–Seasonal variation with peaks after GI viral illness seasons.

PATHOPHYSIOLOGY
–In younger children, the ileum invaginates into the upper colon, bringing the mesentery with it (ileocolic).

–lead point is often lymphoid hyperplasia from viral gastroenteritis

–In older children, ileo-ileo intussusceptions are more common. 
–lead point causes include intestinal polyps, Meckel diverticulum, lymphosarcoma, or even HSP
–Constriction of the mesentery obstructs venous return, leading to bowel ischemia and bloody stools leading to the classic “currant jelly” stool, which is a late finding occurring in about 50% of cases

CLINICAL FEATURES

–Sudden colicky abdominal pain (child will stop, cry, draw up their legs, and then after a few minutes the child appears well). 
–As the condition progresses the time between episodes decreases.   
–Stool is generally guaiac positive even in the absence of gross blood. 
–A palpable sausage shaped mass can be found on the right side of the abdomen in about 2/3 of cases

DIAGNOSIS
–Diagnosis often made by history alone
KUB may suggest a filling defect in the right lower quadrant of the abdomen or can be normal
US can often show the classic target appearance of bowel within bowel (donut sign (transverse); sandwich sign (longitudinal)


TREATMENT
Air contrast enema is preferred over barium enema because it enables better control over colonic pressure and in the case of perforation prevents barium spillage into the peritoneum.
–Children generally admitted for observation because of the 5-10% recurrence rate.  A second attempt at air reduction is usually successful, but if further recurrences occur surgical reduction may be necessary.  

10-SECOND RECAP:
–most common in kids 3 mo-6 yrs old; male:female 4:1

ileocolic (younger), ileo-ileo (older), or wherever

–common lead points (lympoid hyperplasia from gastroenteritis, polyps, meckel’s, cancer, HSP, etc.)
–bowel ischemia -> guaiac+ stool -> occasionally currant jelly stool
history is key, palpable sausage in RLQ in 2/3, KUB maybe, ultrasound (donut/sandwich signs)
air contrast enema = diagnostic + therapeutic; surgery if that doesn’t work


Submitted by J. Grover.


Reference(s): Tintinalli’s Emergency Medicine, picture 1, KUB, donut, sandwich

hyoid bone fracture

27 Jan

QUICK OVERVIEW:
rare, due to protected location of the larynx (mandible is superior and anterior and spine is posterior)

Hyoid bone fractures from blunt trauma other than strangulation = 0.002%
Respiratory distress can progress rapidly: hematoma formation and soft tissue swelling leads to airway compromise and hypoxia

–Laryngeal injuries occur more commonly in males (77% vs 33%)

–Women have slimmer longer necks so they are more prone to hyoid bone fractures
symptoms: horseness, neck pain, dyspnea, dysphonia, aphonia, dysphasia, odynophonia/phagia, stridor (inspiratory), hemoptysis, subcutaneous emphysema, hematoma, ecchymosis, crepitus, loss of landmarks
Associated injuries w/laryngeal fractures: intracranial injury (13%), open neck injury (9%), C-spine fx (8%), esophageal injury (3%)
BOTTOM LINE:
hyoid bone fractures are rare
most are from strangulation, few from blunt trauma
respiratory compromise is the big issue (duh)
–associated with other head & neck badness
Submitted by J. Gullo.

brace vs. cast for Salter I & II distal fibula fractures

26 Jan
QUICK OVERVIEW:
–Isolated non-displaced Salter type I & II distal fibula fx’s and avulsion fx’s are very low risk for long-term complications (i.e. growth arrest – no reports found after lit review)
–For an unstable ankle, the ligaments connecting the tibia, fibula and talus must be broken in 2 places; with Salter I/II fibula fx ligament only broken in 1 place
removable ankle brace (e.g. Air-Stirrup) vs. traditional castsin a non-inferiority RCT single blind study, removable ankle brace patients had…

  • less functional morbidity
  • more rapid return to baseline activity (~80% back to baseline activity with brace in 4 wks, vs ~60% of those with cast)
  • preferred by patient and families
  • more cost-effective
–Can advise parents/patient to expect pain for next 2-4 weeks, full return to competitive sports usually in 6-12 weeks
Submitted by F. DiFranco. 
Reference(s): Boutis, K., et al. A randomized controlled trial of removable brace versus casting in children with low-risk ankle fractures. Pediatrics. 119(6):1256-1263, June 2007; Boutis, K., et al. Common pediatric fractures treated with minimal intervention. Pediatric Emergency Care. 26(2):152-157, Feb. 2010., picture

steroids and sore throat

25 Jan
(scroll to bottom for 10-second version)
REVIEW ARTICLE:
–includes 5 adult trials of IM vs oral steroids for acute pharyngitis
–suggested earlier reduction of pain and shorter time to complete relief as well as 3 pediatric trials using oral dex (0.6 mg/kg to a max of 10 mg) as a single dose or given over 3 days showed earlier pain reduction compared to controls
no benefit to 3 day vs. single dose
META-ANALYSIS:
–includes 8 RCT’s comparing systemic corticosteroids and placebo
–when given with antibiotics, patients who received steroids had an average onset of pain relief 6.3 hours earlier
INTRAMUSCULAR STEROIDS:
–turkish study; single dose IM dex vs. placebo for patients with 2+ Centor criteria
average onset to pain relief of 8.1 hrs in steroid group vs. 19.9 hrs in placebo group
complete pain relief of 28.9 hrs (steroid) vs 53.7 hrs (placebo)
PO vs. IM STEROIDS:
–single dose oral prednisone vs IM dexamethasone
no difference in pain scores or number of hours to relief of pain
10-SECOND RECAP:
steroids in acute pharyngitis: hastens pain relief by about 6-24 hours (vs. placebo)
single dose probably just as good as 3-day course
dexamethasone IM vs. prednisone PO: works about the same
Submitted by F. DiFranco.
Reference(s): Hayward, G., et al. Corticosteroids for pain relief in sore throat: systematic review and meta-analysis. British Medical Journal. 339:b2976, Aug. 2009; Korb, K., et al. Steroids as adjuvant therapy for acute pharyngitis in ambulatory patients: a systematic review. Annals of Family Medicine. 8(1):58, Jan.-Feb. 2010; Marvez-Valls, E., et al. A randomized clinical trial of oral versus intramuscular delivery of steroids in acute exudative pharyngitis. Academic Emergency Medicine. 9(1):1, Jan. 2002; Tasar, A., et al. Clinical efficacy of dexamethasone for acute exudative pharyngitis. Journal of Emergency Medicine. 35(4):363, Nov. 2008; picture

where do patient’s with Marfan Syndrome dissect?

24 Jan

AORTIC DISSECTION & MARFAN SYNDROME:
The major cardiovascular manifestation in Marfan Syndrome is a progressive dilatation of the ascending aorta, leading to aortic aneurysm formation and eventually to fatal aortic rupture or dissection. Aortic dissection in early adult life is the leading cause of death.

The ascending and descending aorta are both abnormal in Marfan Syndrome.

· The descending aorta is affected in two out of three patients during aortic dissection, and is the site of most complications which occur during follow-up.

· Aortic dissection limited to the descending aorta can occur in patients without dilatation of the ascending aorta.

–Dissection of the descending aorta was associated with dissection of ascending aorta in 43% and was isolated in 20% of cases.

BOTTOM LINE:
–dissections in Marfan involve descending aorta ~2/3 of the time, but these frequently involve the ascending aorta also
–if you have a patient with Marfan, and are worried about a dissection…worry about both (ascending/descending)
Submitted by J. Gullo.

Reference(s): PMID: 20232788, medscape article, picture

how often is manual testicular detorsion successful?

24 Jan

STUDY 1:

–over 10 years, looked at 35 of 104 patients who underwent pre-op manual detorsion. 
–of the 34 evaluable patients, all the testes were salvaged (i.e. 100%)

STUDY 2:
–16 Total cases of acute torsion, 15 underwent successful detorsion

93% testicular salvage in the 15 who underwent detorsion

STUDY 3:
14 of 17 patients had successful manual detorsion with no testicular atrophy noted after 22 months
BOTTOM LINE:
–manual testicular detorsion works pretty well
–most torsion is medial, so to detors, twist 180 degrees laterally (like opening a book); should relieve symptoms
–then call urology
Submitted by J. Gullo.
Reference(s): study 1, study 2, study 3, picture