insulin memory aid: Can I tell from the name if its short or longer acting?

30 May

nice memory tool pulled from an April emdocs post:

 

INSULINs:

rapid acting: LOGs (e.g. NovoLog, HumaLog)

short to intermediate acting: LINs

  • Lin R – Short acting (NovoLin R, HumuLin R)
  • Lin N – Intermediate acting (NovoLin N, HumuLin N)

long acting: other stuff (e.g. Lantus, Levemir)

 

There you go. Check out the original post, which has a nice chart on the pharmacokinetics, as well as this handy visual aid, too.

screen-shot-2015-08-16-at-10-53-37-am

 

References: http://www.emdocs.net/core-em-pharmacology-of-insulins/

Cranial Nerve VI Palsy

23 May

Submitted by Christina Brown, M.D.

Definition 

  • Abducens nerve, CN VI
  • a somatic, efferent (motor) nerve that controls a single muscle; lateral rectus. 
  • sixth cranial nerve has the longest subarachnoid course of all the cranial nerves. 
  • sixth nerve nucleus is located in the pons, just ventral to the floor of the fourth ventricle and just lateral to the medial longitudinal fasciculus (MLF) [5].

RBO revisada JAN-FEV-13-en.pmd

Epidemiology 

study of 213 patients with unilateral isolated sixth nerve palsies, non-traumatic

  • 78% experienced spontaneous recovery of their palsy,
  • 37% recovering by 8 weeks
  • 74% by 24 weeks [3].
  • Only 16% failed to recover; of this group, however, almost 40 percent had serious underlying pathology accounting for their palsy.

 

Presentation 

  • primarily c/o horizontal diplopia (double vision producing a side-by-side image with both eyes open). 
  • Patients with idiopathic sixth nerve palsy often present with the sudden onset of horizontal diplopia that is better at near and worse at a distance.
  • Patients also may present with a head-turn to maintain binocularity and to minimize diplopia. [5].  
  • A sudden onset distinguishes idiopathic sixth cranial nerve palsies from tumor or myasthenia gravis [6]. 
  • Other things to pay particular attention to when dealing with sixth nerve palsies
    • fifth nerve (reduced facial sensation, often around the upper face and cornea) pointing to a lesion in the cavernous sinus
    • papilledema, suggesting a mass lesion causing raised intracranial pressure and displacement of the brainstem and thus stretching of one or both sixth nerves.

 

DDx – Giant cell arteritis, Mass Lesion, Myasthenia Gravis, Lyme disease, syphilis, cavernous sinus lesion, Medial Orbital Wall Fracture, Horner’s Syndrome, diabetes, meningitis [1,6]

Evaluation – For idiopathic CNVI palsy, spontaneous improvement over several weeks to months is expected, and failure to improve suggests more serious intracranial pathology.

  • 1st – Onset of presentation? A sudden onset distinguishes idiopathic sixth cranial nerve palsies from tumor or myasthenia gravis.
  • 2nd – Is a single nerve involved? Involvement of other nerves, even the opposite cranial nerve (eg, bilateral sixth nerve palsy), suggests a more serious underlying pathology.
  • 3rd – Is there a medical excuse for the problem? Diabetes, myasthenia gravis, etc.  As an example, one is more likely to work up a young person with a sixth nerve palsy than an older person in his seventies.
  • 4th – Headache? The presence of severe headache of sudden onset demands an urgent evaluation for cerebral aneurysm
  • 5th – Signs of improvement over time? Almost always point to a benign process. Isolated fourth or sixth never palsies can be observed for a few weeks. More extensive work-up should be done if the palsy does not resolve or if other symptoms appear. Persistent esotropia may require a surgical procedure.

 

Management 

  • Ophthalmology C/S if bilateral nerve involvement, CNV involvement, persistent esotropia.
  • Neuroimaging if high clinical suspicion for mass lesion, cerebral aneurysm.
  • If elevated ESR, CRP pointing toward temporal arteritis, start high dose steroids.

 

References: 

  1. http://www.uptodate.com/contents/overview-of-diplopia?source=search_result&search=sixth+nerve+palsy&selectedTitle=1~50#H23
  2. Patel SV, Holmes JM, Hodge DO, Burke JP. Diabetes and hypertension in isolated sixth nerve palsy: a population-based study. Ophthalmology 2005; 112:760.
  3. King AJ, Stacey E, Stephenson G, Trimble RB. Spontaneous recovery rates for unilateral sixth nerve palsies. Eye (Lond) 1995; 9 ( Pt 4):476.
  4. Gutman I, Levartovski S, Goldhammer Y, et al. Sixth nerve palsy and unilateral Horner’s syndrome. Ophthalmology 1986; 93:913.
  5. http://emedicine.medscape.com/article/1198383-overview
  6. Kline LB, Glaser JS. Bilateral abducens nerve palsies from clivus chordoma. Ann Ophthalmol 1981; 13:705.
  7. picture

visual aid: facial nerve blocks

16 May

some very nice nerve landmark photos via a recent EM Docs post:

nerve lineup

the key takeaway here is that you can draw a line vertically through the middle of the eye, and that’s your rough horizontal landmark to aim your needle for a nerve block.

Check out the site, which has a few other useful photos and tips, including this one for the auricular block:

screen-shot-2016-04-24-at-7-06-39-pm-546x1024

 

There you go.

 

References: emdocs post

Pneumocephalus

9 May

submitted by Christina Brown, M.D.

Definition – Air in the cranial vault.  

Mechanically speaking, intracranial air becomes trapped and expands due to a ball valve effect resulting in mass effect, can result in headache and signs and symptoms of increased ICP [5].  

Usually associated with neurosurgery, barotrauma, basilar skull fractures, sinus fractures, nasopharyngeal tumor invasion and meningitis [1, 2].

Presentation

  • Headache and altered consciousness are the most common symptoms [3].
  • Tension pneumocephalus = neurosurgical emergency

Imaging

  • X-rays can diagnose pneumocephalus, but CT scan is the modality of choice.
  • Classical CT sign of tension pneumocephalus = “Mount Fuji sign”: the massive accumulation of air that separates and compresses both frontal lobes and mimics the large volcano in Japan.  

 

Management

Conservative 

  • Neurosurgery C/S. In the vast majority, post-operative pneumocephalus is an expected finding in essentially all post-craniotomy patients.  Most cases of pneumocephalus resolve spontaneously, and conservative management should be provided.  
  • Non-operative management involves oxygen therapy, keeping the head of the bed elevated, prophylactic antimicrobial therapy (especially in post-traumatic cases), analgesia, frequent neurologic checks and repeated CT scans. 

 

Operative – In cases of tension pneumocephalus, a burr hole may need to be performed to relieve pressure. 

 

References

  1. Yildiz A, Duce MN, Ozer C, et al. Disseminated pneumocephalus secondary to an unusual facial trauma. Eur J Radiol. 2002;42:65–68. doi: 10.1016/S0720-048X(01)00383-7. 
  2. Jenson MB, Adams HP. Pneumocephalus after air travel. Neurology. 2004;63:400–401.
  3. Kapoor T, Shetty P. J Emerg Med. 2008;35:453–454. doi: 10.1016/j.jemermed.2007.03.046. 
  4. Satapathy GC, Dash HH. Tension pneumocephalus after neurosurgery in the supine position. Br J Anaesth. 2000;84:115–117. 
  5. Satapathy GC, Dash HH. Tension pneumocephalus after neurosurgery in the supine position. Br J Anaesth. 2000;84 (1): 115-7. Br J Anaesth (abstract)
  6. pictures

 

EM PULMONOLOGY QUICK HITS

31 Mar

Submitted by Amit Kumar, M.D.

ABG vs VBG:

Due to the ease/lack of another stick, VBG often preferred and sufficient in ED.

Two main indications to get ABG for accurate results:

  • patient in severe shock,
  • VBG PCO2 >45mmHg

 

BPAP basics:

-EPAP = CPAP = PEEP

-IPAP = Pressure support (what makes BPAP > CPAP)
Respiratory Failure:

Type I respiratory failure:

  • O2 problem (hypoxia)
  • Ex: ARDS, pneumonia, pulmonary edema, CHF
  • Treatment: ? EPAP, start with FiO2 100%

Type 2 respiratory failure:

  • CO2 problem (hypercarbia)
  • Ex: COPD, asthma
  • Treatment: ? IPAP, may start with FiO2 ~40% (hypoxia not the problem)

 

Continuous EtCO2 uses in ED:

Definition: Partial pressure of CO2 in exhaled breath

-During procedural sedation: Measure of ventilation. Increase to >50mm Hg/>10mmHg from baseline usually indication of oncoming hypoxia (in theory, hypoventillation preceeds hypoxia)

-During CPR: Measure of cardiac output. <10 mmHg hints towards inadequate compressions –> switch. Sudden increase (to ~35-45 mmHg) is a sign of ROSC.

 

References:

EM: RAP (Resp Failure types)

http://www.alaskasleep.com/blog/what-is-bipap-therapy-machine-bilevel-positive-airway-pressure (BiPAP vs CPAP)

http://www.med.upenn.edu/emig/capnography%20for%20procedural%20sedation%20in%20the%20ED.pdf (EtCO2 + procedural sedation)

 

 

C1-C2 Fractures (quick review)

23 Feb

Submitted by Christina Brown, M.D.

C1-C2 FRACTURES/DISRUPTION

Occipital Condyle Fracture  – Neurologic impairment such as lower cranial nerve deficits and/or limb weakness.  It’s rarely visible on plain films.

Occipito-atlantal Disassociation –Skull displaced anteriorly/posteriorly or distracted from cervical spine.  It frequently results in death.  “Basion-dental interval” – Distance between basion and superior cortex of dens.  Normally distance is less than 8.5mm on CT. (1)

C1 (ATLAS) Fractures

 Jefferson Fx.  – Due to axial loading resulting in outward displacement of lateral masses of C1.  If displacement is >7mm in total, rupture of the transverse ligament and likely unstable.  (1)

Transverse Ligament Disruption – TV ligament is crucial to stability of C1 and C2. 

  • On lateral radiograph, the predental space should be less than 3mm in adults vs <2mm on CT. 
  • A predental space >3mm on lateral radiograph implies damage to TV ligament. 
  • >5mm indicates rupture. 

Avulsion Fx of Anterior or Posterior Arch of Atlas – Hyperextension injury.  Lateral XR.  An isolated avulsion of anterior tubercle is considered a stable fracture. 

 

C2 (AXIS) Fractures

Odontoid Fx – Frequently involve other injuries to cervical spine and multisystem trauma.  Clinical signs – Severe, high cervical pain w/ muscle spasm worsened by movement.  Neurologic injury in 18-25% odontoid fractures ranging from paresthesias to quadriplegia.  (1)

Type I – Avulsion of tip.  Stable, good prognosis. 

Type II – Junction of odontoid w/ body of C2, unstable. 

Type III – Through body of C2.  Unstable.  (1)

 

 

Hangman’s Fx – C2 (Axis) pedicle fractures.  Unstable injury d/t hyperextension following abrupt deceleration. 

Initial Management

Spinal Immobilization – There is no high quality evidence stating that it prevents spinal injury or improves outcome (2).  It’s recommended to remove patient from the backboard as soon as possible. 

Definitive Management – If a spinal column injury is deemed unstable, hospital admission and spine surgery consultation is mandatory.

Conservative Management – Closed reduction under fluoroscopy and halo-vest immobilization. The halo vest = graphite or metal and is secured to the frontal and parietal areas of the skull with metal pins.  The halo is the most common device applied for treatment of unstable cervical fractures.  (4)

 

Common Pitfalls

  • No spine immobilization
  • Low suspicion of spinal injury in multi trauma patient
  • Accepting radiographs that are inadequate to appropriately evaluate for spinal column injury
  • Failure to appreciate the high false negative rate of plain radiographs in diagnosing unstable burst fractures; failure to obtain a CT scan in such cases (2)
  • Failure to radiograph the entire spine when a fracture at one spinal level is demonstrated

 

 

References:

  1. Baron BJ, McSherry KJ, Larson JL, Jr., Scalea TM. Baron B.J., McSherry K.J., Larson J.L., Jr., Scalea T.M. Baron, Bonny J., et al.Chapter 255. Spine and Spinal Cord Trauma. In: Tintinalli JE, Stapczynski J, Ma O, Cline DM, Cydulka RK, Meckler GD, T. Tintinalli J.E., Stapczynski J, Ma O, Cline D.M., Cydulka R.K., Meckler G.D., T Judith E. Tintinalli, et al.eds.Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. New York, NY: McGraw-Hill; 2011. http://accessmedicine.mhmedical.com/content.aspx?bookid=348&Sectionid=40381743
  2. http://www.uptodate.com/contents/evaluation-and-acute-management-of-cervical-spinal-column-injuries-in-adults?source=search_result&search=cervical+fracture&selectedTitle=2~30
  3. http://www.uptodate.com/contents/spinal-column-injuries-in-adults-definitions-mechanisms-and-radiographs?source=search_result&search=cervical+fracture&selectedTitle=1~30
  4. Botte MJ, Byrne TP, Abrams RA, Garfin SR. Halo Skeletal Fixation: Techniques of Application and Prevention of Complications. J Am Acad Orthop Surg 1996; 4:44.
  1. Images +: https://www.med-ed.virginia.edu/courses/rad/cspine/index.html
  2. Odontoid types image: http://accessemergencymedicine.mhmedical.com/data/Books/schw1/schw1_c042f012.gif 

 

strength in numbers: Pyelonephritis

3 Feb

some interesting stats, via a recent emdocs overview of pyelonephritis:

Clinical:

  • fever – present in up to 77% of patients
  • flank pain or CVA tenderness – 86%
  • elderly patients with NO fever – up to 33% (just to make our jobs difficult)

 

Urinalysis:

  • needs 10,000 colony forming units (CFU) per mm3 to confirm diagnosis
  • leukocyte esterase (LE):
    • sensitivity: 72% to 97%
    • specificity: 41% to 86%
  • nitrites:
    • sensitivity: 19% to 48%
    • specificity: 92% to 100%
  • Urine cultures positive in 90%

urine-analysis-28-638

Patient with symptoms, but negative dipstick: what now?

“urine dipstick showed sensitivities as low as 75%, which is not acceptable if the patient has symptoms.”

also beware of pyelo mimics (e.g. pneumonia, PE, AAA, chronic pyelonephritis, PID, pelvic pain syndrome, prostatitis, diverticulitis, appendicitis, ovarian/testicular torsion, HZV, epidural abscess, and ectopic pregnancy)

 

Food for thought.

 

References: emdocs article; picture

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