52 Articles: Lysis vs Transfer for PCI (NEJM 2003)

ST segments:
fear
a lytic in my hand,
or transfer?

-Unknown, 2015

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

Discussing:

Andersen et al., NEJM 2003.  A Comparison of Coronary Angioplasty with Fibrinolytic Therapy in Acute Myocardial Infarction.

Main Points:

  1. This prospective randomly-controlled trial investigated whether patients with STEMIs who presented to community hospitals would benefit from transport to specialized centers for percutaneous coronary intervention (PCI) rather than remaining at the local hospital for fibrinolysis. The authors demonstrated an almost 5% reduction in reinfarction rate at 30 days between the two groups.
  1.  STEMI patients that presented to community centers and received aspirin+metoprolol+heparin+PCI within 2 hours, including transfer time, had statistically significantly fewer reinfarctions at 30 days than the STEMI patients who remained at the initial facility andon alteplase+aspirin+metoprolol+heparin.  Ultimately, PCI was shown to be superior to fibrinolytic if available in a timely fashion.

Background:

It is now an established tenet that timely PCI in an experienced center by experienced interventionalists is the best treatment for STEMI.  Historically, with no PCI available at the presenting facility, STEMI patients received anticoagulation and fibrinolytics.  But there were obvious and dangerous concerns in applying a “PCI-or-bust” policy universally, as there are only so many PCI centers to drive patients to, and “time is myocardium.”  So the best treatment for the patient with a STEMI in the middle of the proverbial forest was unknown.  Lyse or transfer?  This study made significant progress towards helping us answer this question.

Methods:

1572 patients were enrolled, 1129 from 24 referral hospitals and 443 from 5 PCI centers.  All of these patients were randomly assigned to receive lysis & anticoagulation (LA) or anticoagulation & PCI (APCI), with the patients from the referral hospitals therefore being transferred for their PCI.  And yes, patients who presented to PCI centers and were assigned LA therefore did not receive PCI.  Risk characteristics of all the patients were similar.  LA patients received 300mg aspirin PO, 20mg metoprolol IV, an “accelerated” alteplase treatment (15mg bolus + 0.75mg/kg over 30min + 0.5mg/kg over the next 60min), and unfractionated heparin for 48h (5000U bolus + infusion titrated to aPTT 70-90sec).  APCI patients received 300mg aspirin IV, 20mg metoprolol IV, unfractionated heparin (10,000U bolus + infusion during procedure to activated clotting time 350-450s).  In patients receiving PCI, GPIIb/IIIa blockers were given at discretion of proceduralist, arteries were treated only if stenosed >30% or if TIMI “flow grade” was <3, non-infarct-related arteries were NOT intervened on, and all patient received Ticlodipine (500mg) or Clopidogrel (75mg) for 1 month afterwards.  The primary endpoint was a composite of death from any cause, clinical reinfarction, or disabling stroke at 30 days follow up.

Results:

  • For patients presenting to PCI centers, there was a 45% reduction in composite outcome with PCI, from 12.3% in the LA group to 6.7% in the APCI group (P = 0.05).
  • For patients presenting to referral hospitals, there was a 40% reduction in the composite outcome with PCI, from 14.2% in the LA group to 8.5% in the APCI group (P = 0.002)
  • Driving the difference within the composite outcome was clinical reinfarction: 1.6% in all APCI vs 6.3% in all LA (P =  0.001).  Differences in death and stroke rates at 30 days were not statistically significantly different between all APCI and all LA patients, whether they were transferred to a PCI center or were already there.
  • The median distance from referral site to PCI center was 50 km
  • Transfer was highly protocolized, with emphasis on shaving-off every precious second of ischemic time.  This cooperation and efficiency resulted in 96% of referral patients landing on the nearest participating PCI table in 2 hours or less.
  • The study was stopped after the 1129 patients, when the third interim analysis showed referral APCIs were reinfarcting less than the referral LAs; this was built into the design as a study cutoff as it implies that APCI is better in both settings.

Discussion:

  • The bottom line is the balance between the proven benefits of PCI and the ischemic time on the myocardium.  There are many variables at play in the “lyse vs transfer (vs both)” decision (see below). These variables include: location and severity of the ischemia, comorbidities and stability of the patient, EMS capabilities, distance, receiving PCI center experience, available medications, etc.  The decision may not always be clear, every patient is probably different, and there is an overwhelming amount of research on this topic.  Do your best.
  • Implementing the airtight transfer logistics they executed here is an obstacle, science aside.
  • In hindsight, your heart has to go out (no pun intended) to the 12.3% of LA patients who presented to a PCI center, got heparin & alteplase, and had a poor outcome.  Their willingness to participate has certainly saved lives.
  • Did you notice that the referred APCI patients did not receive fibrinolysis, only asa, metoprolol, and UFH?  The older research on immediate PCI after fibrinolysis showed no benefit and increased adverse effects.  New and ongoing research on “facilitated PCI,” or PCI after fibrinolysis, using ever-advancing interventional equipment and techniques, may be changing this for some high risk patients for whom PCI is not available within 90 minutes.  For further reading, see these:

Herrmann HC, et al.  Benefit of facilitated percutaneous coronary intervention in high-risk ST-segment elevation myocardial infarction patients presenting to nonpercutaneous coronary intervention hospitals.  JACC Cardiovac Interv.  2009 Oct;2(10):917-24.

Ellis SG, et al.  Facilitated PCI in patients with ST-elevation myocardial infarction.  N Engl J Med. 2008 Maay 22;358(21):2205-17.

Ellis SG, et al. Facilitated percutaneous coronary intervention versus primary percutaneous coronary intervention: design and rationale of the Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events (FINESSE) trial. Am Heart J. 2004; 147: E16.

Level of Evidence:

Based on the ACEP grading system for therapeutic questions this study was graded level I.

Surprises:

The study inclusion criteria was defined as the symptoms for greater than 30 minutes, but less than 12 hours with associated cumulative ST-segment elevation of at least 4mm in at least two contiguous leads.

Resident Reviewer: Dr. Kazakin
Faculty Reviewer: Dr. Siket

Peds EM Follow Up 2015: Pediatric Osteomyelitis

2 Articles of Interest & An Excruciating, Detailed and Lengthy Guide to Diagnosis and Management

 

Dartnell J, Ramachandran M, Katchburian M. Haematogenous Acute and Subacute Paediatric Osteomyelitis: A Systematic Review of the Literature. J Bone Joint Surg Br. 2012 May;94(5):584-95.

  • A meta-analysis of 1854 papers, 132 of which were examined in detail
  • 40% of patients were afebrile
  • Tibia and femur were most common sites
  • Exam, labs, and imaging must be used in combination
  • S. aureus > Kingella > other
  • Typical treatment: start empiric IV abx, switch to PO when possible

Harris JC, et al. How Useful are Laboratory Investigations in the Emergency Department Evaluation of Possible Osteomyelitis? Emerg Med Australias. 2011 Jun;23(3):317-30. Epub 2011 Apr 4

  • A meta-analysis of 36 studies of adults and children
  • Recommended algorithm:
    • Adults and kids w/ low pretest probability: nL ESR and CRP<5 → done
    • Med/high pretest probability and puncture wounds: nL ESR and CRP<5 → LOW NPV
    • ESR >30 and/or CRP>10-30 → further investigation (imaging) required
    • WBC count is not especially helpful!

Osteo locations

 

PEDIATRIC OSTEOMYELITIS:

  • Definition: bacteria infecting bone
  • Usually hematogenous spread, but can be direct inoculation (surgery, open trauma, puncture, etc) or contiguous spread (skin, sinus, dental infections)

CLINICAL PRESENTATION

  • Constitutional symptoms, irritability, decreased PO
  • +/- fever
  • Localized pain, bony tenderness
  • Functional limitations, i.e. unwilling to crawl or walk
  • Time course: usually several days to >1 week
  • Risk factors: bacteremia, sepsis, immunocompromised, indwelling catheters/hardware, prematurity, skin infection, complicated delivery, GU abnormalities

Continue reading

EUS: Retinal Detachment & SSTIs

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Brown Ultrasound Tape Review:  9:24:2015

 

ARTICLE #1  –  Suddenly, painlessly blind?  Keep calm and get the Ultrasound.

Vrablik et al.  The Diagnostic Accuracy of Bedside Ocular Ultrasonography for the Diagnosis of Retinal Detachment: A Systematic Review and Meta-analysis.  Annals of Emergency Medicine 2014; 20: 1-6.

 In this systematic review, Vrablik et al assessed the diagnostic accuracy of ED Ocular US for retinal detachment.  They whittled 7771 unique citations down to 4 trials that included a total of 201 ED patients, where EUS Dx was compared to Ophthalmologic evaluation and/or Orbital CT.  Prevalence was 15-38%, sensitivity and specificity of EUS were 97-100% and 83-100%, respectively.

 This modality may be helpful because 1) vision-threatening complaints are time sensitive, 2) formal dilated fundoscopic exam may be impractical or impossible in the busy ED setting, and 3) formal Ophtho consultation may be limited or unavailable in some EDs.  These studies were small and participating physician training was variable, but results showed that we can reliably make this diagnosis in the ED with a linear array probe.

  We discussed distinguishing retinal detachment from vitreous hemorrhage or vitreous detachment (keeping in mind these are not mutually exclusive).  Retinal detachment classically presents as sudden, painless, monocular visual impairment, like “looking through a curtain.”  EUS will show the “sail sign”, a funnel shaped, sharply defined, reflective, linear membrane anchored to the optic disc and waving serpiginously as the patient moves their eyes.  In vitreous detachment the patient may describe “floaters” or “flashes of light” that move with eye movement, and EUS will show the “seaweed sign”: fine, granular, swirling echogenic debris in the posterior eye, with no tethering to the disc.

Retinal_detachment  Retinal Detachment  (www.foamem.com)

Vtreous_Detachment_main  Vitreous Detachment  (www.ultrasoundvillage.com)

 

 

ARTICLE #2  –  To incise, or not to incise, that is the question.

Squire et al.  ABSCESS: Applied Bedside Sonography for Convenient Evaluation of Superficial Soft Tissue Infections.  Academic Emergency Medicine 2005; 12(7): 6011-607.

 This study investigated the utility of EUS in detecting subcutaneous abscesses in 107 patients with presentations concerning for cellulitis vs abscess.  Residents and Attendings who had received a 30min training session were eligible, and their Clinical and EUS diagnoses for “+/- abscess” were compared to +/- pus with I&D, or +/- antibiotic failure at 7 day follow up (failure meaning most likely it was an abscess).

 

Sensitivity NPV Specificity PPV
Clinical Dx 86% 77% 70% 81%
EUS Dx 98% 97% 88% 93%

 

Interestingly, there were 18 cases where EUS and Clinical Dx disagreed, and EUS proved correct in 94% (n=17) of them: 9 of the negative Clinical Dx cases (23%) became positive with EUS, and 9 of the positive Clinical Dx cases (13%) became negative with EUS.  Many of the ED sonographers also discovered nerves and vessels, which changed management…most significantly for 4 of the falsely positive Clinical Dx patients, of whom 3 had hematomas and 1 had an aneurysm (#whoathatwasclose).  But while the investigators did prove that EUS can more accurately identify abscesses, they did not report any patient-centered outcomes, such as less antibiotic use, faster recovery, fewer complications, fewer return visits, or less recurrence.  So in summary, it remains to be seen whether the findings here should definitely change practice at this time.

 We also reviewed the EUS-for-abscess technique: with the linear probe placed on the skin, an abscess will appear as a hypoechoic heterogeneic mass, generally spherical with ill-defined borders, and with variable internal echoes (pus) that will “swirl” with compression.  Cellulitis is generally more hyperechoic and more uniform.

 

BROWNsound BONUS:   TAPE REVIEW RAPID FIRE!

– Achilles Tendon rupture: appears as a defect with surrounding hypoechoic hemorrhage

– B lines (lung US):

     1) must obliterate the A lines

     2) must be linear

     3) must go 18cm deep

     4) must be persistent

     5) must be more than 3 per zone

     6) must be more than 2 rib spaces per side to support HF

– Appendicitis:

     1) must be non-compressible

     2) must be a blind-ended pouch

     3) must be tender-to-palpation

     4) must be 6mm outside-to-outside to be “too big”

– Tamponade:  RV must collapse during diastole

– IUP:

     1) In the sagittal view the bladder apex correlates with the cervix, which may helps avoid confusion between the vagina and the endometrial stripe

     2) Key cutoff:  fluid tracking <2/3 up the uterus (in the caudal direction) may be physiologic; >2/3 is more likely pathologic

 

EUS: Comprehensive LE DVT studies & LP Guidance

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Brown Ultrasound Tape Review – 9:17:15

 

ARTICLE #1  –  If “2-Point Compression” is Good, Would “5-Point Compression” Be More Good?

Srikar et al.  Isolated Deep Venous Thrombosis: Implications for 2-Point Compression Ultrasonography of the Lower Extremity. Annals of Emergency Medicine 2015; 66: 262-267

For the evaluation of DVT, the American Institute of Ultrasound in Medicine recommends compressibility and spectral Doppler waveforms of the Common Femoral, proximal Deep Femoral, Femoral, Popliteal, and proximal Great Saphenous veins.  But ever since Bernardi et al found equivalence with “2-Point Compression” plus D-Dimer, many ER physicians have been employing this faster technique at the bedside, which uses compressibility and direct visualization of the Common Femoral and Popliteal veins only.  This study questioned whether we should consider assessing more veins by investigating the prevalence of thrombi elsewhere in symptomatic patients.  This was a 6 year retrospective study of 2451 symptomatic patients who received “comprehensive” studies of the Common Femoral, Deep Femoral, Femoral, Popliteal, and Calf veins, which were interpreted by vascular surgeons. Continue reading

ROCKstars – Case 1: US-Guided Central Venous Access (CIV)

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An elderly patient is in the RIH Critical Care bay with severe sepsis and needs central access.  Luckily, Drs. Adam “Hyperechoic” Haag and Eddie “Rule ‘Em Out” Ruhland are on shift.  They settle on the right Internal Jugular vein, but traditional sternocleidomastoid muscle (SCM) and clavicular bone landmarks are not apparent.  So a linear-array probe is correctly placed transversely over the triangle formed by the bifurcation of the SCM, to where the IJ and Carotid are seen in parallel…but there is some sort of hyperechoic, noncompressible mass…

They identify the thrombus, and instead find the Femoral vein, where CIV access is successfully achieved on the first attempt with no immediate complications.  The use of US to guide this procedure changed this patient’s course and potentially saved a complication.  

But exactly how much safer, faster, and more reliable is US-guided CIV placement?

THE ISSUE

  • Vascular access is critical in emergent situations
  • Body habitus, dehydration, poor perfusion, anatomical abnormalities, or history of IVDU can cause difficulties and delays when using landmark-based techniques
  • Complications of CIV placement include arterial puncture, excessive bleeding, vessel laceration, pneumothorax, hemothorax, and necessitation of multiple attempts
  • US guidance was identified in 2001 by United States Agency for Healthcare Research and Quality as one of the top 11 means of increasing patient safety, but this was based on one study of subclavian lines at one large urban center (1)

The “SOAP-3” Trial (2005)

  • A concealed, randomized, controlled study of 201 patients
  • Studies dating back to the 1990s in EM and Anesthesia (4) had demonstrated the efficacy of ultrasound-guidance, but this was the first study in the ED setting comparing the anatomical landmark method, the static “quick look” US-guided method, and dynamic “real time” US-guided method
  • In the “quick look” group, US was used to identify landmarks, the skin was marked, and the catheter was placed without real-time US guidance
  • EM residents and Attendings passed a 1h training course, then placed 10 CIVs with dynamic US guidance to qualify to participate

RESULTS

Dynamic

US Guidance

Static

US Guidance

Anatomical Landmarks Method
Overall Success 98% 82% 64%
First-Attempt Success

(OR vs LM)

5.8 3.4
Avg # of Attempts 1.7 1.6 3.2
Avg Total Sec 30 20 150
Complications 2 2 8

DISCUSSION

  • Dynamic guidance is superior but requires the most training
  • Static guidance is vastly superior to Landmark, and while slightly inferior to Dynamic, it requires less training
  • 10% of the study patients had “extremely narrow” (<5mm) IJs bilaterally, which could explain the inferior performance of the LM technique, even with experienced practitioners
  • All the complications were arterial punctures, and these were not statistically significant

References

  1. Agency for Health Care Research and Quality (AHRQ). Evidence Report/Technology Assessment: Number 43. Making Health Care Safer. A Critical Analysis of Patient Safety Practices: Summary 2001. 2007.
  1. Milling, et al. Randomized, controlled clinical trial of point-of-care limited ultrasonography assistance of central venous cannulation: The Third Sonography Outcomes Assessment Program (SOAP-3) Trial.  Critical Care Medicine, 2005, Aug;33(8); 1764-9.
  1. Sulek et al.  A Randomized Study of Left versus Right Internal Jugular Vein Cannulation in Adults.  J Clin Anesth, 2000, Mar; 12(2): 142-5
  1. www.sonoguide.com/line_placement.html

EUS for Increased ICP & Proximal Lower Extremity DVT

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Brown Ultrasound Tape Review  –  9:3:2015

 

Article #1:  Increased ICP via Optic Nerve Sheath Diameter (ONSD)

Amini, et al. (2013). Use of the Sonographic Diameter of Optic Nerve Sheath to Estimate Intracranial Pressure. American Journal of Emergency Medicine 2013; 31: 236–239.

In this 2013 study, Amini et al measured the ONSD of 50 non-traumatized patients undergoing LP and found that an ONSD >5.5mm correlated with an ICP >20mm Hg with a sensitivity and specificity of 100%.  While this sounds great, we discussed well known concerns regarding inter-operator reliability and the technical aspects of accurately measuring the ONSD; measuring Optic Disc elevation is an alternative strategy.

The bottom line:   while normal ONSD measurements cannot rule out increased ICP, it may be a useful adjunct in patients with low pre-test probability.

 

Article #2:  Proximal Lower Extremity DVT

Crisp, et al. (2010).  Compression Ultrasonography of the Lower Extremity with Portable Vascular Ultrasonography Can Accurately Detect Deep Vein Thrombosis in the Emergency Department.  Annals of Emergency Medicine 2010; 56 (6): 601-611.

In this 2010 study by Crisp et al, 47 ED physicians performed “2 Point Compression” on the Common Femoral and Popliteal veins in 199 patients, and their results were compared to the “comprehensive” results from the Department of Radiology studies that each patient also received.  The physicians took a 10 minutes training session, and the test was “positive” if a thrombus was visualized, or if the vein was non-compressible.  When compared to the Radiology results, the ED docs were 100% sensitive and specific for DVTs in these locations.  Our discussion centered around whether calf veins (which 2 Point Compression does not search for) are worth searching for (no one knows).

The bottom line:  2-point compression with a D-Dimer (and follow up comprehensive study if positive) may be an acceptable strategy for the management of DVT in the ED.

 

Special thanks and credit to Jon Thorndike