Archive | July, 2015

strength in numbers: subarachnoid hemorrhage

30 Jul

via a recent EP monthly article on acute SAH vs. traumatic tap:

 

sensitivity of CT for diagnosing aSAH: 93% (95% CI 89-96%)

sensitivity of CT  within 6 hrs of headache onset: 100% (95% CI 97-100%)

sensitivity of CT beyond 6 hrs: 86% (95% CI 78-91%)

 

traumatic taps in up to 30% of LPs

 

one study (caveats: required dx of aneurysmal aSAH on CTA, and 8/15 SAH dx by LP were missed on initial CT read):

  • cutoff of <2000 x 10^6/L  CSF RBCs: 93% sensitivity (CI 66-99.7%)
  • cutoff of <2000… RBCs + no xanthochromia: 100% sensitivity (CI 74.7-100%)
  • only 15 cases of aSAH diagnosed by LP at 12 academic centers in 10 years
  • interesting, but not practice changing just yet

 

Food for thought.

 

References: epmonthly article, picture

Humeral IO

28 Jul

back from vacation with some quick procedural tips via a recent EM Resident article:

HUMERAL INTRAOSSEOUS (IO) ACCESS:

Basics:

  • proximal humerus
  • higher flow rates vs. tibia (~ 2x)
  • closer proximity to central circulation

 

Contraindications (to any IO site):

  • unhealed fracture
  • active soft tissue infection
  • previous IO attempt within 48 hrs
  • inability to find landmarks
  • joint replacement/prosthetic

 

The Procedure:

  • Positioning (3 possibilities):
    • palm over the umbilicus
    • flexed arm behind back (i.e. palm “under” the umbilicus) — useful during CPR
    • elbow extended, adducted, hyperpronated (i.e. straight arm by side, hyperprone)

  •  Placement:
    • palpate greater tubercle
    • feel surgical neck
    • pick site 1 cm above surgical neck
    • aim 45 degree angle towards contralateral hip

There you go.  Add it to the toolbox.

 

References: EM Resident article + picture; humerus picture

 

 

visual aid: ultrasound for pneumothorax

21 Jul

great visual aid reminders for the ultrasound findings for a normal lung vs. pneumothorax via June’s Emed Journal:

Linear probe

2nd intercostal space, mid-clavicular, anterior chest wall

NORMAL LUNG (“waves on the beach”)

 

PNEUMOTHORAX (barcode sign)

References: emed journal article

What is Palcohol?

17 Jul

some tidbits for the near-the-horizon coming of Powdered ALCOHOL (Palcohol), via this month’s EM News:

 

concentrated powdered alcohol

>= 55% alcohol by weight, 10% by volume

palcohol

the idea:

mix with warm water, imbibe

the concerns:

hidden ingestion (e.g. slipping it into drinks, spiking food)

non-PO routes (e.g. snorting, IV)

 

deterrents (hopefully)

volume — packet says 200ml with water added, so would take a lot powder to spike/snort/shoot 1 shot of liquor’s worth

pain — snorting or IV injection seems caustic and painful

 

There you go.  Be on the lookout.

 

References: EM News article + picture; SA article

 

ACUTE LIMB ISCHEMIA

14 Jul

manifests as:

  • ischemic rest pain
  • ischemic ulcers
  • gangrene

 

ETIOLOGY 

  • Embolus from a proximal source lodging into a more distal vessel
  • dissection of an artery or direct trauma to an artery

 

RISK FACTORS

  • atrial fibrillation,
  • Recent myocardial infarction
  • Aortic atherosclerosis,
  • aneurysmal disease (eg, aortic aneurysm, popliteal aneurysm)
  • Prior lower extremity revascularization (angioplasty/stent, bypass graft),
  • Risk factors for aortic dissection (HTN, etc)
  • Arterial trauma
  • Deep vein thrombosis (paradoxical embolism)
  • left ventricular dysfunction
  • debris from prosthetic valves and infected cardiac valves (septic emboli)

 

Arterial Trauma — Acute arterial occlusion following interventional procedures has become a more frequent cause — the incidence of arterial complications following interventional cardiac catheterization is ~1.5 to 9 percent 

 

6 P’s

  • paresthesia,
  • pain,
  • pallor,
  • pulselessness,
  • poikilothermia,
  • paralysis

 

Variations Blue toe syndrome — sudden appearance of a cool, painful, cyanotic toe(s) or forefoot in the often perplexing presence of strong pedal pulses and a warm foot.  The blue toe syndrome is usually due to embolic occlusion of digital arteries with atherothrombotic material from proximal arterial sources.

IMAGING 

First LineComputed tomographic angiography with runoff, noninvasive duplex ultrasonography, or magnetic resonance angiography

 

MANAGEMENT

intravenous heparin bolus followed by a continuous heparin infusion 

Preoperative eval, including blood tests (PT/PTT, CBC) and electrocardiography (ECG)

Surgical thromboembolectomy and bypass grafting – Were the mainstays of therapy for many years. Subsequently, thrombolytic therapy and percutaneous transluminal angioplasty (PTA) have become treatment options for selected patients. 

Consult Vascular Surgery.

Submitted by Christina Brown.

 

References: uptodate.com, Norgren L, Hiatt WR, Dormandy JA, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg 2007; 45 Suppl S:S5Nasser TK, Mohler ER 3rd, Wilensky RL, Hathaway DR. Peripheral vascular complications following coronary interventional procedures. Clin Cardiol 1995; 18:609.Alonso-Coello P, Bellmunt S, McGorrian C, et al. Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012; 141:e669S.Yeager RA, Moneta GL, Taylor LM Jr, et al. Surgical management of severe acute lower extremity ischemia. J Vasc Surg 1992; 15:385.; picture 

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.

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